Intel(R) SGX is a set of CPU instructions that can be used by applications
to set aside private regions of code and data. The code outside the enclave
is disallowed to access the memory inside the enclave by the CPU access
control. In a way you can think that SGX provides inverted sandbox. It
protects the application from a malicious host.
There is a new hardware unit in the processor called Memory Encryption
Engine (MEE) starting from the Skylake microacrhitecture. BIOS can define
one or many MEE regions that can hold enclave data by configuring them with
PRMRR registers.
The MEE automatically encrypts the data leaving the processor package to
the MEE regions. The data is encrypted using a random key whose life-time
is exactly one power cycle.
The current implementation requires that the firmware sets
IA32_SGXLEPUBKEYHASH* MSRs as writable so that ultimately the kernel can
decide what enclaves it wants run. The implementation does not create
any bottlenecks to support read-only MSRs later on.
You can tell if your CPU supports SGX by looking into /proc/cpuinfo:
cat /proc/cpuinfo | grep sgx
v15:
* Split into more digestable size patches.
* Lots of small fixes and clean ups.
* Signal a "plain" SIGSEGV on an EPCM violation.
v14:
* Change the comment about X86_FEATURE_SGX_LC from “SGX launch
configuration” to “SGX launch control”.
* Move the SGX-related CPU feature flags as part of the Linux defined
virtual leaf 8.
* Add SGX_ prefix to the constants defining the ENCLS leaf functions.
* Use GENMASK*() and BIT*() in sgx_arch.h instead of raw hex numbers.
* Refine the long description for CONFIG_INTEL_SGX_CORE.
* Do not use pr_*_ratelimited() in the driver. The use of the rate limited
versions is legacy cruft from the prototyping phase.
* Detect sleep with SGX_INVALID_EINIT_TOKEN instead of counting power
cycles.
* Manually prefix with “sgx:” in the core SGX code instead of redefining
pr_fmt.
* Report if IA32_SGXLEPUBKEYHASHx MSRs are not writable in the driver
instead of core because it is a driver requirement.
* Change prompt to bool in the entry for CONFIG_INTEL_SGX_CORE because the
default is ‘n’.
* Rename struct sgx_epc_bank as struct sgx_epc_section in order to match
the SDM.
* Allocate struct sgx_epc_page instances one at a time.
* Use “__iomem void *” pointers for the mapped EPC memory consistently.
* Retry once on SGX_INVALID_TOKEN in sgx_einit() instead of counting power
cycles.
* Call enclave swapping operations directly from the driver instead of
calling them .indirectly through struct sgx_epc_page_ops because indirect
calls are not required yet as the patch set does not contain the KVM
support.
* Added special signal SEGV_SGXERR to notify about SGX EPCM violation
errors.
v13:
* Always use SGX_CPUID constant instead of a hardcoded value.
* Simplified and documented the macros and functions for ENCLS leaves.
* Enable sgx_free_page() to free active enclave pages on demand
in order to allow sgx_invalidate() to delete enclave pages.
It no longer performs EREMOVE if a page is in the process of
being reclaimed.
* Use PM notifier per enclave so that we don't have to traverse
the global list of active EPC pages to find enclaves.
* Removed unused SGX_LE_ROLLBACK constant from uapi/asm/sgx.h
* Always use ioremap() to map EPC banks as we only support 64-bit kernel.
* Invalidate IA32_SGXLEPUBKEYHASH cache used by sgx_einit() when going
to sleep.
v12:
* Split to more narrow scoped commits in order to ease the review process and
use co-developed-by tag for co-authors of commits instead of listing them in
the source files.
* Removed cruft EXPORT_SYMBOL() declarations and converted to static variables.
* Removed in-kernel LE i.e. this version of the SGX software stack only
supports unlocked IA32_SGXLEPUBKEYHASHx MSRs.
* Refined documentation on launching enclaves, swapping and enclave
construction.
* Refined sgx_arch.h to include alignment information for every struct that
requires it and removed structs that are not needed without an LE.
* Got rid of SGX_CPUID.
* SGX detection now prints log messages about firmware configuration issues.
v11:
* Polished ENCLS wrappers with refined exception handling.
* ksgxswapd was not stopped (regression in v5) in
sgx_page_cache_teardown(), which causes a leaked kthread after driver
deinitialization.
* Shutdown sgx_le_proxy when going to suspend because its EPC pages will be
invalidated when resuming, which will cause it not function properly
anymore.
* Set EINITTOKEN.VALID to zero for a token that is passed when
SGXLEPUBKEYHASH matches MRSIGNER as alloc_page() does not give a zero
page.
* Fixed the check in sgx_edbgrd() for a TCS page. Allowed to read offsets
around the flags field, which causes a #GP. Only flags read is readable.
* On read access memcpy() call inside sgx_vma_access() had src and dest
parameters in wrong order.
* The build issue with CONFIG_KASAN is now fixed. Added undefined symbols
to LE even if “KASAN_SANITIZE := false” was set in the makefile.
* Fixed a regression in the #PF handler. If a page has
SGX_ENCL_PAGE_RESERVED flag the #PF handler should unconditionally fail.
It did not, which caused weird races when trying to change other parts of
swapping code.
* EPC management has been refactored to a flat LRU cache and moved to
arch/x86. The swapper thread reads a cluster of EPC pages and swaps all
of them. It can now swap from multiple enclaves in the same round.
* For the sake of consistency with SGX_IOC_ENCLAVE_ADD_PAGE, return -EINVAL
when an enclave is already initialized or dead instead of zero.
v10:
* Cleaned up anon inode based IPC between the ring-0 and ring-3 parts
of the driver.
* Unset the reserved flag from an enclave page if EDBGRD/WR fails
(regression in v6).
* Close the anon inode when LE is stopped (regression in v9).
* Update the documentation with a more detailed description of SGX.
v9:
* Replaced kernel-LE IPC based on pipes with an anonymous inode.
The driver does not require anymore new exports.
v8:
* Check that public key MSRs match the LE public key hash in the
driver initialization when the MSRs are read-only.
* Fix the race in VA slot allocation by checking the fullness
immediately after succeesful allocation.
* Fix the race in hash mrsigner calculation between the launch
enclave and user enclaves by having a separate lock for hash
calculation.
v7:
* Fixed offset calculation in sgx_edbgr/wr(). Address was masked with PAGE_MASK
when it should have been masked with ~PAGE_MASK.
* Fixed a memory leak in sgx_ioc_enclave_create().
* Simplified swapping code by using a pointer array for a cluster
instead of a linked list.
* Squeezed struct sgx_encl_page to 32 bytes.
* Fixed deferencing of an RSA key on OpenSSL 1.1.0.
* Modified TC's CMAC to use kernel AES-NI. Restructured the code
a bit in order to better align with kernel conventions.
v6:
* Fixed semaphore underrun when accessing /dev/sgx from the launch enclave.
* In sgx_encl_create() s/IS_ERR(secs)/IS_ERR(encl)/.
* Removed virtualization chapter from the documentation.
* Changed the default filename for the signing key as signing_key.pem.
* Reworked EPC management in a way that instead of a linked list of
struct sgx_epc_page instances there is an array of integers that
encodes address and bank of an EPC page (the same data as 'pa' field
earlier). The locking has been moved to the EPC bank level instead
of a global lock.
* Relaxed locking requirements for EPC management. EPC pages can be
released back to the EPC bank concurrently.
* Cleaned up ptrace() code.
* Refined commit messages for new architectural constants.
* Sorted includes in every source file.
* Sorted local variable declarations according to the line length in
every function.
* Style fixes based on Darren's comments to sgx_le.c.
v5:
* Described IPC between the Launch Enclave and kernel in the commit messages.
* Fixed all relevant checkpatch.pl issues that I have forgot fix in earlier
versions except those that exist in the imported TinyCrypt code.
* Fixed spelling mistakes in the documentation.
* Forgot to check the return value of sgx_drv_subsys_init().
* Encapsulated properly page cache init and teardown.
* Collect epc pages to a temp list in sgx_add_epc_bank
* Removed SGX_ENCLAVE_INIT_ARCH constant.
v4:
* Tied life-cycle of the sgx_le_proxy process to /dev/sgx.
* Removed __exit annotation from sgx_drv_subsys_exit().
* Fixed a leak of a backing page in sgx_process_add_page_req() in the
case when vm_insert_pfn() fails.
* Removed unused symbol exports for sgx_page_cache.c.
* Updated sgx_alloc_page() to require encl parameter and documented the
behavior (Sean Christopherson).
* Refactored a more lean API for sgx_encl_find() and documented the behavior.
* Moved #PF handler to sgx_fault.c.
* Replaced subsys_system_register() with plain bus_register().
* Retry EINIT 2nd time only if MSRs are not locked.
v3:
* Check that FEATURE_CONTROL_LOCKED and FEATURE_CONTROL_SGX_ENABLE are set.
* Return -ERESTARTSYS in __sgx_encl_add_page() when sgx_alloc_page() fails.
* Use unused bits in epc_page->pa to store the bank number.
* Removed #ifdef for WQ_NONREENTRANT.
* If mmu_notifier_register() fails with -EINTR, return -ERESTARTSYS.
* Added --remove-section=.got.plt to objcopy flags in order to prevent a
dummy .got.plt, which will cause an inconsistent size for the LE.
* Documented sgx_encl_* functions.
* Added remark about AES implementation used inside the LE.
* Removed redundant sgx_sys_exit() from le/main.c.
* Fixed struct sgx_secinfo alignment from 128 to 64 bytes.
* Validate miscselect in sgx_encl_create().
* Fixed SSA frame size calculation to take the misc region into account.
* Implemented consistent exception handling to __encls() and __encls_ret().
* Implemented a proper device model in order to allow sysfs attributes
and in-kernel API.
* Cleaned up various "find enclave" implementations to the unified
sgx_encl_find().
* Validate that vm_pgoff is zero.
* Discard backing pages with shmem_truncate_range() after EADD.
* Added missing EEXTEND operations to LE signing and launch.
* Fixed SSA size for GPRS region from 168 to 184 bytes.
* Fixed the checks for TCS flags. Now DBGOPTIN is allowed.
* Check that TCS addresses are in ELRANGE and not just page aligned.
* Require kernel to be compiled with X64_64 and CPU_SUP_INTEL.
* Fixed an incorrect value for SGX_ATTR_DEBUG from 0x01 to 0x02.
v2:
* get_rand_uint32() changed the value of the pointer instead of value
where it is pointing at.
* Launch enclave incorrectly used sigstruct attributes-field instead of
enclave attributes-field.
* Removed unused struct sgx_add_page_req from sgx_ioctl.c
* Removed unused sgx_has_sgx2.
* Updated arch/x86/include/asm/sgx.h so that it provides stub
implementations when sgx in not enabled.
* Removed cruft rdmsr-calls from sgx_set_pubkeyhash_msrs().
* return -ENOMEM in sgx_alloc_page() when VA pages consume too much space
* removed unused global sgx_nr_pids
* moved sgx_encl_release to sgx_encl.c
* return -ERESTARTSYS instead of -EINTR in sgx_encl_init()
Jarkko Sakkinen (12):
x86/sgx: Update MAINTAINERS
x86/sgx: Define SGX1 and SGX2 ENCLS leafs
x86/sgx: Add ENCLS architectural error codes
x86/sgx: Add SGX1 and SGX2 architectural data structures
x86/sgx: Add definitions for SGX's CPUID leaf and variable sub-leafs
x86/sgx: Add wrappers for ENCLS leaf functions
x86/sgx: Add functions to allocate and free EPC pages
platform/x86: Intel SGX driver
platform/x86: sgx: Add swapping functionality to the Intel SGX driver
x86/sgx: Add a simple swapper for the EPC memory manager
platform/x86: ptrace() support for the SGX driver
x86/sgx: Driver documentation
Kai Huang (2):
x86/cpufeatures: Add Intel-defined SGX feature bit
x86/cpufeatures: Add Intel-defined SGX_LC feature bit
Sean Christopherson (9):
x86/cpufeatures: Add SGX sub-features (as Linux-defined bits)
x86/msr: Add IA32_FEATURE_CONTROL.SGX_ENABLE definition
x86/cpu/intel: Detect SGX support and update caps appropriately
x86/mm: x86/sgx: Add new 'PF_SGX' page fault error code bit
x86/mm: x86/sgx: Signal SIGSEGV for userspace #PFs w/ PF_SGX
x86/msr: Add SGX Launch Control MSR definitions
x86/cpu/intel: Clear SGX_LC capability if not enabled in
FEATURE_CONTROL
x86/sgx: Enumerate and track EPC sections
x86/sgx: Add sgx_einit() for initializing enclaves
Documentation/index.rst | 1 +
Documentation/x86/intel_sgx.rst | 185 ++++
MAINTAINERS | 7 +
arch/x86/Kconfig | 18 +
arch/x86/include/asm/cpufeatures.h | 23 +-
arch/x86/include/asm/msr-index.h | 8 +
arch/x86/include/asm/sgx.h | 326 ++++++
arch/x86/include/asm/sgx_arch.h | 400 +++++++
arch/x86/include/asm/traps.h | 1 +
arch/x86/include/uapi/asm/sgx.h | 59 ++
arch/x86/include/uapi/asm/sgx_errno.h | 91 ++
arch/x86/kernel/cpu/Makefile | 1 +
arch/x86/kernel/cpu/intel.c | 29 +
arch/x86/kernel/cpu/intel_sgx.c | 479 +++++++++
arch/x86/kernel/cpu/scattered.c | 2 +
arch/x86/mm/fault.c | 13 +
drivers/platform/x86/Kconfig | 2 +
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/intel_sgx/Kconfig | 20 +
drivers/platform/x86/intel_sgx/Makefile | 14 +
drivers/platform/x86/intel_sgx/sgx.h | 212 ++++
drivers/platform/x86/intel_sgx/sgx_encl.c | 977 ++++++++++++++++++
.../platform/x86/intel_sgx/sgx_encl_page.c | 178 ++++
drivers/platform/x86/intel_sgx/sgx_fault.c | 109 ++
drivers/platform/x86/intel_sgx/sgx_ioctl.c | 234 +++++
drivers/platform/x86/intel_sgx/sgx_main.c | 267 +++++
drivers/platform/x86/intel_sgx/sgx_util.c | 156 +++
drivers/platform/x86/intel_sgx/sgx_vma.c | 167 +++
tools/arch/x86/include/asm/cpufeatures.h | 21 +-
29 files changed, 3989 insertions(+), 12 deletions(-)
create mode 100644 Documentation/x86/intel_sgx.rst
create mode 100644 arch/x86/include/asm/sgx.h
create mode 100644 arch/x86/include/asm/sgx_arch.h
create mode 100644 arch/x86/include/uapi/asm/sgx.h
create mode 100644 arch/x86/include/uapi/asm/sgx_errno.h
create mode 100644 arch/x86/kernel/cpu/intel_sgx.c
create mode 100644 drivers/platform/x86/intel_sgx/Kconfig
create mode 100644 drivers/platform/x86/intel_sgx/Makefile
create mode 100644 drivers/platform/x86/intel_sgx/sgx.h
create mode 100644 drivers/platform/x86/intel_sgx/sgx_encl.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_encl_page.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_fault.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_ioctl.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_main.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_util.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_vma.c
--
2.19.1
Add the maintainer information for the SGX subsystem.
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 02a39617ec82..a5597a89c7a9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7595,6 +7595,13 @@ L: [email protected]
S: Maintained
F: drivers/gpio/gpio-intel-mid.c
+INTEL SGX
+M: Jarkko Sakkinen <[email protected]>
+L: [email protected]
+Q: https://patchwork.kernel.org/project/intel-sgx/list/
+F: drivers/platform/x86/intel_sgx/
+K: \bSGX_
+
INVENSENSE MPU-3050 GYROSCOPE DRIVER
M: Linus Walleij <[email protected]>
L: [email protected]
--
2.19.1
From: Kai Huang <[email protected]>
X86_FEATURE_SGX reflects whether or not the CPU supports Intel's
Software Guard eXtensions (SGX).
Signed-off-by: Kai Huang <[email protected]>
---
arch/x86/include/asm/cpufeatures.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 89a048c2faec..22271752fd1e 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -236,6 +236,7 @@
/* Intel-defined CPU features, CPUID level 0x00000007:0 (EBX), word 9 */
#define X86_FEATURE_FSGSBASE ( 9*32+ 0) /* RDFSBASE, WRFSBASE, RDGSBASE, WRGSBASE instructions*/
#define X86_FEATURE_TSC_ADJUST ( 9*32+ 1) /* TSC adjustment MSR 0x3B */
+#define X86_FEATURE_SGX ( 9*32+ 2) /* Software Guard Extensions */
#define X86_FEATURE_BMI1 ( 9*32+ 3) /* 1st group bit manipulation extensions */
#define X86_FEATURE_HLE ( 9*32+ 4) /* Hardware Lock Elision */
#define X86_FEATURE_AVX2 ( 9*32+ 5) /* AVX2 instructions */
--
2.19.1
From: Sean Christopherson <[email protected]>
CPUID_12_EAX is an Intel-defined feature bits leaf dedicated for SGX
that enumerates the SGX instruction sets that are supported by the
CPU, e.g. SGX1, SGX2, etc... Because Linux currently only cares about
two bits (SGX1 and SGX2) and there are currently only four documented
bits in total, relocate the bits to Linux-defined word 8 to conserve
space.
But, keep the bit positions identical between the Intel-defined value
and the Linux-defined value, e.g. keep SGX1 at bit 0. This allows KVM
to use its existing code for probing guest CPUID bits using Linux's
X86_FEATURE_* definitions. To do so, shift around some existing bits
to effectively reserve bits 0-7 of word 8 for SGX sub-features.
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/include/asm/cpufeatures.h | 21 +++++++++++++++------
arch/x86/kernel/cpu/scattered.c | 2 ++
tools/arch/x86/include/asm/cpufeatures.h | 21 +++++++++++++++------
3 files changed, 32 insertions(+), 12 deletions(-)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 22271752fd1e..1b8dea9a06cb 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -222,12 +222,21 @@
#define X86_FEATURE_L1TF_PTEINV ( 7*32+29) /* "" L1TF workaround PTE inversion */
#define X86_FEATURE_IBRS_ENHANCED ( 7*32+30) /* Enhanced IBRS */
-/* Virtualization flags: Linux defined, word 8 */
-#define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */
-#define X86_FEATURE_VNMI ( 8*32+ 1) /* Intel Virtual NMI */
-#define X86_FEATURE_FLEXPRIORITY ( 8*32+ 2) /* Intel FlexPriority */
-#define X86_FEATURE_EPT ( 8*32+ 3) /* Intel Extended Page Table */
-#define X86_FEATURE_VPID ( 8*32+ 4) /* Intel Virtual Processor ID */
+/*
+ * Scattered Intel features: Linux defined, word 8.
+ *
+ * Note that the bit location of the SGX features is meaningful as KVM expects
+ * the Linux defined bit to match the Intel defined bit, e.g. X86_FEATURE_SGX1
+ * must remain at bit 0, SGX2 at bit 1, etc...
+ */
+#define X86_FEATURE_SGX1 ( 8*32+ 0) /* SGX1 leaf functions */
+#define X86_FEATURE_SGX2 ( 8*32+ 1) /* SGX2 leaf functions */
+
+#define X86_FEATURE_TPR_SHADOW ( 8*32+ 8) /* Intel TPR Shadow */
+#define X86_FEATURE_VNMI ( 8*32+ 9) /* Intel Virtual NMI */
+#define X86_FEATURE_FLEXPRIORITY ( 8*32+10) /* Intel FlexPriority */
+#define X86_FEATURE_EPT ( 8*32+11) /* Intel Extended Page Table */
+#define X86_FEATURE_VPID ( 8*32+12) /* Intel Virtual Processor ID */
#define X86_FEATURE_VMMCALL ( 8*32+15) /* Prefer VMMCALL to VMCALL */
#define X86_FEATURE_XENPV ( 8*32+16) /* "" Xen paravirtual guest */
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 772c219b6889..f7f0970b8f89 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -26,6 +26,8 @@ static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_CDP_L3, CPUID_ECX, 2, 0x00000010, 1 },
{ X86_FEATURE_CDP_L2, CPUID_ECX, 2, 0x00000010, 2 },
{ X86_FEATURE_MBA, CPUID_EBX, 3, 0x00000010, 0 },
+ { X86_FEATURE_SGX1, CPUID_EAX, 0, 0x00000012, 0 },
+ { X86_FEATURE_SGX2, CPUID_EAX, 1, 0x00000012, 0 },
{ X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
{ X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
{ X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/include/asm/cpufeatures.h
index 89a048c2faec..9cc7628b9845 100644
--- a/tools/arch/x86/include/asm/cpufeatures.h
+++ b/tools/arch/x86/include/asm/cpufeatures.h
@@ -222,12 +222,21 @@
#define X86_FEATURE_L1TF_PTEINV ( 7*32+29) /* "" L1TF workaround PTE inversion */
#define X86_FEATURE_IBRS_ENHANCED ( 7*32+30) /* Enhanced IBRS */
-/* Virtualization flags: Linux defined, word 8 */
-#define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */
-#define X86_FEATURE_VNMI ( 8*32+ 1) /* Intel Virtual NMI */
-#define X86_FEATURE_FLEXPRIORITY ( 8*32+ 2) /* Intel FlexPriority */
-#define X86_FEATURE_EPT ( 8*32+ 3) /* Intel Extended Page Table */
-#define X86_FEATURE_VPID ( 8*32+ 4) /* Intel Virtual Processor ID */
+/*
+ * Scattered Intel features: Linux defined, word 8.
+ *
+ * Note that the bit numbers of the SGX features are meaningful as KVM expects
+ * the Linux defined bit to match the Intel defined bit, e.g. X86_FEATURE_SGX1
+ * must remain at bit 0, SGX2 at bit 1, etc...
+ */
+#define X86_FEATURE_SGX1 ( 8*32+ 0) /* SGX1 leaf functions */
+#define X86_FEATURE_SGX2 ( 8*32+ 1) /* SGX2 leaf functions */
+
+#define X86_FEATURE_TPR_SHADOW ( 8*32+ 8) /* Intel TPR Shadow */
+#define X86_FEATURE_VNMI ( 8*32+ 9) /* Intel Virtual NMI */
+#define X86_FEATURE_FLEXPRIORITY ( 8*32+10) /* Intel FlexPriority */
+#define X86_FEATURE_EPT ( 8*32+11) /* Intel Extended Page Table */
+#define X86_FEATURE_VPID ( 8*32+12) /* Intel Virtual Processor ID */
#define X86_FEATURE_VMMCALL ( 8*32+15) /* Prefer VMMCALL to VMCALL */
#define X86_FEATURE_XENPV ( 8*32+16) /* "" Xen paravirtual guest */
--
2.19.1
From: Sean Christopherson <[email protected]>
Add a new IA32_FEATURE_CONTROL bit, SGX_ENABLE, which must be set in
order to execute SGX instructions, i.e. ENCL{S,U,V}. The existence of
the bit is enumerated by CPUID as X86_FEATURE_SGX. Like all other
flags in IA32_FEATURE_CONTROL, the MSR must be locked for SGX_ENABLE
to take effect.
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/include/asm/msr-index.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 4731f0cf97c5..2837f65ac817 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -486,6 +486,7 @@
#define FEATURE_CONTROL_LOCKED (1<<0)
#define FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX (1<<1)
#define FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX (1<<2)
+#define FEATURE_CONTROL_SGX_ENABLE (1<<18)
#define FEATURE_CONTROL_LMCE (1<<20)
#define MSR_IA32_APICBASE 0x0000001b
--
2.19.1
From: Sean Christopherson <[email protected]>
Similar to other large Intel features such as VMX and TXT, SGX must be
explicitly enabled in IA32_FEATURE_CONTROL MSR to be truly usable.
Clear all SGX related capabilities if SGX is not fully enabled in
IA32_FEATURE_CONTROL or if the SGX1 instruction set isn't supported
(impossible on bare metal, theoretically possible in a VM if the VMM
is doing something weird).
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/kernel/cpu/intel.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index fc3c07fe7df5..9bf8fe2c04ac 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -596,6 +596,30 @@ static void detect_tme(struct cpuinfo_x86 *c)
c->x86_phys_bits -= keyid_bits;
}
+static void detect_sgx(struct cpuinfo_x86 *c)
+{
+ bool unsupported = false;
+ unsigned long long fc;
+
+ rdmsrl(MSR_IA32_FEATURE_CONTROL, fc);
+ if (!(fc & FEATURE_CONTROL_LOCKED)) {
+ pr_err_once("sgx: IA32_FEATURE_CONTROL MSR is not locked\n");
+ unsupported = true;
+ } else if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) {
+ pr_err_once("sgx: not enabled in IA32_FEATURE_CONTROL MSR\n");
+ unsupported = true;
+ } else if (!cpu_has(c, X86_FEATURE_SGX1)) {
+ pr_err_once("sgx: SGX1 instruction set not supported\n");
+ unsupported = true;
+ }
+
+ if (unsupported) {
+ setup_clear_cpu_cap(X86_FEATURE_SGX);
+ setup_clear_cpu_cap(X86_FEATURE_SGX1);
+ setup_clear_cpu_cap(X86_FEATURE_SGX2);
+ }
+}
+
static void init_intel_energy_perf(struct cpuinfo_x86 *c)
{
u64 epb;
@@ -763,6 +787,9 @@ static void init_intel(struct cpuinfo_x86 *c)
if (cpu_has(c, X86_FEATURE_TME))
detect_tme(c);
+ if (cpu_has(c, X86_FEATURE_SGX))
+ detect_sgx(c);
+
init_intel_energy_perf(c);
init_intel_misc_features(c);
--
2.19.1
From: Sean Christopherson <[email protected]>
The SGX bit is set in the #PF error code if and only if the fault is
detected by the Enclave Page Cache Map (EPCM), a hardware-managed
table that enforces the paging permissions defined by the enclave,
e.g. to prevent the kernel from changing the permissions of an
enclave's page(s).
Cc: Dave Hansen <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/include/asm/traps.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 3de69330e6c5..165c93dd700e 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -162,5 +162,6 @@ enum x86_pf_error_code {
X86_PF_RSVD = 1 << 3,
X86_PF_INSTR = 1 << 4,
X86_PF_PK = 1 << 5,
+ X86_PF_SGX = 1 << 15,
};
#endif /* _ASM_X86_TRAPS_H */
--
2.19.1
From: Sean Christopherson <[email protected]>
The PF_SGX bit is set if and only if the #PF is detected by the SGX
Enclave Page Cache Map (EPCM). The EPCM is a hardware-managed table
that enforces accesses to an enclave's EPC pages in addition to the
software-managed kernel page tables, i.e. the effective permissions
for an EPC page are a logical AND of the kernel's page tables and
the corresponding EPCM entry.
The EPCM is consulted only after an access walks the kernel's page
tables, i.e.:
a. the access was allowed by the kernel
b. the kernel's tables have become less restrictive than the EPCM
c. the kernel cannot fixup the cause of the fault
Noteably, (b) implies that either the kernel has botched the EPC
mappings or the EPCM has been invalidated (see below). Regardless of
why the fault occurred, userspace needs to be alerted so that it can
take appropriate action, e.g. restart the enclave. This is reinforced
by (c) as the kernel doesn't really have any other reasonable option,
i.e. signalling SIGSEGV is actually the least severe action possible.
Although the primary purpose of the EPCM is to prevent a malicious or
compromised kernel from attacking an enclave, e.g. by modifying the
enclave's page tables, do not WARN on a #PF w/ PF_SGX set. The SGX
architecture effectively allows the CPU to invalidate all EPCM entries
at will and requires that software be prepared to handle an EPCM fault
at any time. The architecture defines this behavior because the EPCM
is encrypted with an ephemeral key that isn't exposed to software. As
such, the EPCM entries cannot be preserved across transitions that
result in a new key being used, e.g. CPU power down as part of an S3
transition or when a VM is live migrated to a new physical system.
Cc: Andy Lutomirski <[email protected]>
Cc: Dave Hansen <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/mm/fault.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 47bebfe6efa7..11d16bcf6e64 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1153,6 +1153,19 @@ access_error(unsigned long error_code, struct vm_area_struct *vma)
if (error_code & X86_PF_PK)
return 1;
+ /*
+ * Access is blocked by the Enclave Page Cache Map (EPCM), i.e. the
+ * access is allowed by the PTE but not the EPCM. This usually happens
+ * when the EPCM is yanked out from under us, e.g. by hardware after a
+ * suspend/resume cycle. In any case, software, i.e. the kernel, can't
+ * fix the source of the fault as the EPCM can't be directly modified
+ * by software. Handle the fault as an access error in order to signal
+ * userspace, e.g. so that userspace can rebuild their enclave(s), even
+ * though userspace may not have actually violated access permissions.
+ */
+ if (unlikely(error_code & X86_PF_SGX))
+ return 1;
+
/*
* Make sure to check the VMA so that we do not perform
* faults just to hit a X86_PF_PK as soon as we fill in a
--
2.19.1
ENCLS, a.k.a. Enclave System instruction, is an umbrella instruction
for a variety of privileged SGX functions. The ENCLS function to be
executed is specified in EAX, a la GETSEC of SMX/TXT fame. Leafs may
use additional registers for function-specific operands. ENCLS also
introduces its own set of error codes that (some) leafs use to return
pass/fail information to software. Leafs that return an error code
also modify RFLAGS. And finally, ENCLS generates ENCLS-specific #GPs
and #PFs.
ENCLS leafs functions are organized under SGX sub-features, e.g. SGX1
defines the base ENCLS function set and SGX2 adds ENCLS functions to
enable dynamic EPC management. At this time, only the SGX1 and SGX2
function sets are supported by Linux; the other published sets relate
to VMM EPC oversubscription, which is far out on the horizon.
Define the ENCLS leafs in a dedicated file as more architecturally
defined SGX constants and data structures will be introduced in short
order.
Co-developed-by: Sean Christopherson <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
arch/x86/include/asm/sgx_arch.h | 54 +++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)
create mode 100644 arch/x86/include/asm/sgx_arch.h
diff --git a/arch/x86/include/asm/sgx_arch.h b/arch/x86/include/asm/sgx_arch.h
new file mode 100644
index 000000000000..e068db46835e
--- /dev/null
+++ b/arch/x86/include/asm/sgx_arch.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/**
+ * Copyright(c) 2016-18 Intel Corporation.
+ *
+ * Contains data structures defined by the SGX architecture. Data structures
+ * defined by the Linux software stack should not be placed here.
+ */
+#ifndef _ASM_X86_SGX_ARCH_H
+#define _ASM_X86_SGX_ARCH_H
+
+/**
+ * enum sgx_encls_leaves - ENCLS leaf functions
+ * %SGX_ECREATE: Create an enclave.
+ * %SGX_EADD: Add a page to an uninitialized enclave.
+ * %SGX_EINIT: Initialize an enclave, i.e. launch an enclave.
+ * %SGX_EREMOVE: Remove a page from an enclave.
+ * %SGX_EDBGRD: Read a word from an enclve (peek).
+ * %SGX_EDBGWR: Write a word to an enclave (poke).
+ * %SGX_EEXTEND: Measure 256 bytes of an added enclave page.
+ * %SGX_ELDB: Load a swapped page in blocked state.
+ * %SGX_ELDU: Load a swapped page in unblocked state.
+ * %SGX_EBLOCK: Change page state to blocked i.e. entering hardware
+ * threads cannot access it and create new TLB entries.
+ * %SGX_EPA: Create a Version Array (VA) page used to store isvsvn
+ * number for a swapped EPC page.
+ * %SGX_EWB: Swap an enclave page to the regular memory. Checks that
+ * all threads have exited that were in the previous
+ * shoot-down sequence.
+ * %SGX_ETRACK: Start a new shoot down sequence. Used to together with
+ * EBLOCK to make sure that a page is safe to swap.
+ * %SGX_EAUG: Add a page to an initialized enclave.
+ * %SGX_EMODPR: Restrict an EPC page's permissions.
+ * %SGX_EMODT: Modify the page type of an EPC page.
+ */
+enum sgx_encls_leaves {
+ SGX_ECREATE = 0x00,
+ SGX_EADD = 0x01,
+ SGX_EINIT = 0x02,
+ SGX_EREMOVE = 0x03,
+ SGX_EDGBRD = 0x04,
+ SGX_EDGBWR = 0x05,
+ SGX_EEXTEND = 0x06,
+ SGX_ELDB = 0x07,
+ SGX_ELDU = 0x08,
+ SGX_EBLOCK = 0x09,
+ SGX_EPA = 0x0A,
+ SGX_EWB = 0x0B,
+ SGX_ETRACK = 0x0C,
+ SGX_EAUG = 0x0D,
+ SGX_EMODPR = 0x0E,
+ SGX_EMODT = 0x0F,
+};
+
+#endif /* _ASM_X86_SGX_ARCH_H */
--
2.19.1
Define the data structures used by various ENCLS functions needed for
Linux to support all SGX1 and SGX2 ENCLS leaf functions. This is not
an exhaustive representation of all SGX data structures as several are
only consumed by ENCLU (userspace), e.g. REPORT and KEYREQUEST, while
others are only consumed by future features, e.g. RDINFO.
Co-developed-by: Sean Christopherson <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
arch/x86/include/asm/sgx_arch.h | 329 ++++++++++++++++++++++++++++++++
1 file changed, 329 insertions(+)
diff --git a/arch/x86/include/asm/sgx_arch.h b/arch/x86/include/asm/sgx_arch.h
index 6cd572fa95fa..d4c57154e6e6 100644
--- a/arch/x86/include/asm/sgx_arch.h
+++ b/arch/x86/include/asm/sgx_arch.h
@@ -8,6 +8,7 @@
#ifndef _ASM_X86_SGX_ARCH_H
#define _ASM_X86_SGX_ARCH_H
+#include <linux/types.h>
#include <uapi/asm/sgx_errno.h>
/**
@@ -53,4 +54,332 @@ enum sgx_encls_leaves {
SGX_EMODT = 0x0F,
};
+#define SGX_MODULUS_SIZE 384
+
+/**
+ * enum sgx_miscselect - additional information to an SSA frame
+ * %SGX_MISC_EXINFO: Report #PF or #GP to the SSA frame.
+ *
+ * Save State Area (SSA) is a stack inside the enclave used to store processor
+ * state when an exception or interrupt occurs. This enum defines additional
+ * information stored to an SSA frame.
+ */
+enum sgx_miscselect {
+ SGX_MISC_EXINFO = BIT(0),
+ SGX_MISC_RESERVED_MASK = GENMASK_ULL(63, 1)
+};
+
+#define SGX_SSA_GPRS_SIZE 182
+#define SGX_SSA_MISC_EXINFO_SIZE 16
+
+/**
+ * enum sgx_attributes - the attributes field in &struct sgx_secs
+ * %SGX_ATTR_INIT: Enclave can be entered (is initialized).
+ * %SGX_ATTR_DEBUG: Allow ENCLS(EDBGRD) and ENCLS(EDBGWR).
+ * %SGX_ATTR_MODE64BIT: Tell that this a 64-bit enclave.
+ * %SGX_ATTR_PROVISIONKEY: Allow to use provisioning keys for remote
+ * attestation.
+ * %SGX_ATTR_EINITTOKENKEY: Allow to use token signing key that is used to
+ * sign cryptographic tokens that can be passed to
+ * EINIT as an authorization to run an enclave.
+ */
+enum sgx_attribute {
+ SGX_ATTR_INIT = BIT(0),
+ SGX_ATTR_DEBUG = BIT(1),
+ SGX_ATTR_MODE64BIT = BIT(2),
+ SGX_ATTR_PROVISIONKEY = BIT(4),
+ SGX_ATTR_EINITTOKENKEY = BIT(5),
+ SGX_ATTR_RESERVED_MASK = BIT_ULL(3) | GENMASK_ULL(63, 6)
+};
+
+#define SGX_SECS_RESERVED1_SIZE 24
+#define SGX_SECS_RESERVED2_SIZE 32
+#define SGX_SECS_RESERVED3_SIZE 96
+#define SGX_SECS_RESERVED4_SIZE 3836
+
+/**
+ * struct sgx_secs - SGX Enclave Control Structure (SECS)
+ * @size: size of the address space
+ * @base: base address of the address space
+ * @ssa_frame_size: size of an SSA frame
+ * @miscselect: additional information stored to an SSA frame
+ * @attributes: attributes for enclave
+ * @xfrm: XSave-Feature Request Mask (subset of XCR0)
+ * @mrenclave: SHA256-hash of the enclave contents
+ * @mrsigner: SHA256-hash of the public key used to sign the SIGSTRUCT
+ * @isvprodid: a user-defined value that is used in key derivation
+ * @isvsvn: a user-defined value that is used in key derivation
+ *
+ * SGX Enclave Control Structure (SECS) is a special enclave page that is not
+ * visible in the address space. In fact, this structure defines the address
+ * range and other global attributes for the enclave and it is the first EPC
+ * page created for any enclave. It is moved from a temporary buffer to an EPC
+ * by the means of ENCLS(ECREATE) leaf.
+ */
+struct sgx_secs {
+ u64 size;
+ u64 base;
+ u32 ssa_frame_size;
+ u32 miscselect;
+ u8 reserved1[SGX_SECS_RESERVED1_SIZE];
+ u64 attributes;
+ u64 xfrm;
+ u32 mrenclave[8];
+ u8 reserved2[SGX_SECS_RESERVED2_SIZE];
+ u32 mrsigner[8];
+ u8 reserved3[SGX_SECS_RESERVED3_SIZE];
+ u16 isvprodid;
+ u16 isvsvn;
+ u8 reserved4[SGX_SECS_RESERVED4_SIZE];
+} __packed;
+
+/**
+ * enum sgx_tcs_flags - execution flags for TCS
+ * %SGX_TCS_DBGOPTIN: If enabled allows single-stepping and breakpoints
+ * inside an enclave. It is cleared by EADD but can
+ * be set later with EDBGWR.
+ */
+enum sgx_tcs_flags {
+ SGX_TCS_DBGOPTIN = 0x01,
+ SGX_TCS_RESERVED_MASK = GENMASK_ULL(63, 1)
+};
+
+#define SGX_TCS_RESERVED_SIZE 4024
+
+/**
+ * struct sgx_tcs - Thread Control Structure (TCS)
+ * @state: used to mark an entered TCS
+ * @flags: execution flags (cleared by EADD)
+ * @ssa_offset: SSA stack offset relative to the enclave base
+ * @ssa_index: the current SSA frame index (cleard by EADD)
+ * @nr_ssa_frames: the number of frame in the SSA stack
+ * @entry_offset: entry point offset relative to the enclave base
+ * @exit_addr: address outside the enclave to exit on an exception or
+ * interrupt
+ * @fs_offset: offset relative to the enclave base to become FS
+ * segment inside the enclave
+ * @gs_offset: offset relative to the enclave base to become GS
+ * segment inside the enclave
+ * @fs_limit: size to become a new FS-limit (only 32-bit enclaves)
+ * @gs_limit: size to become a new GS-limit (only 32-bit enclaves)
+ *
+ * Thread Control Structure (TCS) is an enclave page visible in its address
+ * space that defines an entry point inside the enclave. A thread enters inside
+ * an enclave by supplying address of TCS to ENCLU(EENTER). A TCS can be entered
+ * by only one thread at a time.
+ */
+struct sgx_tcs {
+ u64 state;
+ u64 flags;
+ u64 ssa_offset;
+ u32 ssa_index;
+ u32 nr_ssa_frames;
+ u64 entry_offset;
+ u64 exit_addr;
+ u64 fs_offset;
+ u64 gs_offset;
+ u32 fs_limit;
+ u32 gs_limit;
+ u8 reserved[SGX_TCS_RESERVED_SIZE];
+} __packed;
+
+/**
+ * struct sgx_pageinfo - an enclave page descriptor
+ * @addr: address of the enclave page
+ * @contents: pointer to the page contents
+ * @metadata: pointer either to a SECINFO or PCMD instance
+ * @secs: address of the SECS page
+ */
+struct sgx_pageinfo {
+ u64 addr;
+ u64 contents;
+ u64 metadata;
+ u64 secs;
+} __packed __aligned(32);
+
+
+/**
+ * enum sgx_page_type - bits in the SECINFO flags defining the page type
+ * %SGX_PAGE_TYPE_SECS: a SECS page
+ * %SGX_PAGE_TYPE_TCS: a TCS page
+ * %SGX_PAGE_TYPE_REG: a regular page
+ * %SGX_PAGE_TYPE_VA: a VA page
+ * %SGX_PAGE_TYPE_TRIM: a page in trimmed state
+ */
+enum sgx_page_type {
+ SGX_PAGE_TYPE_SECS = 0,
+ SGX_PAGE_TYPE_TCS = 1,
+ SGX_PAGE_TYPE_REG = 2,
+ SGX_PAGE_TYPE_VA = 3,
+ SGX_PAGE_TYPE_TRIM = 4,
+ SGX_PAGE_TYPE_MASK = GENMASK(7, 0)
+};
+
+/**
+ * enum sgx_secinfo_flags - the flags field in &struct sgx_secinfo
+ * %SGX_SECINFO_R: allow read
+ * %SGX_SECINFO_W: allow write
+ * %SGX_SECINFO_X: allow execution
+ * %SGX_SECINFO_SECS: a SECS page
+ * %SGX_SECINFO_TCS: a TCS page
+ * %SGX_SECINFO_REG: a regular page
+ * %SGX_SECINFO_VA: a VA page
+ * %SGX_SECINFO_TRIM: a page in trimmed state
+ */
+enum sgx_secinfo_flags {
+ SGX_SECINFO_R = BIT(0),
+ SGX_SECINFO_W = BIT(1),
+ SGX_SECINFO_X = BIT(2),
+ SGX_SECINFO_PERMISSION_MASK = GENMASK_ULL(2, 0),
+ SGX_SECINFO_SECS = (SGX_PAGE_TYPE_SECS << 8),
+ SGX_SECINFO_TCS = (SGX_PAGE_TYPE_TCS << 8),
+ SGX_SECINFO_REG = (SGX_PAGE_TYPE_REG << 8),
+ SGX_SECINFO_VA = (SGX_PAGE_TYPE_VA << 8),
+ SGX_SECINFO_TRIM = (SGX_PAGE_TYPE_TRIM << 8),
+ SGX_SECINFO_PAGE_TYPE_MASK = (SGX_PAGE_TYPE_MASK << 8),
+ SGX_SECINFO_RESERVED_MASK = ~(SGX_SECINFO_PERMISSION_MASK |
+ SGX_SECINFO_PAGE_TYPE_MASK)
+};
+
+#define SGX_SECINFO_RESERVED_SIZE 56
+
+/**
+ * struct sgx_secinfo - describes attributes of an EPC page
+ * @flags: permissions and type
+ *
+ * Used together with ENCLS leaves that add or modify an EPC page to an
+ * enclave to define page permissions and type.
+ */
+struct sgx_secinfo {
+ u64 flags;
+ u8 reserved[SGX_SECINFO_RESERVED_SIZE];
+} __packed __aligned(64);
+
+#define SGX_PCMD_RESERVED_SIZE 40
+
+/**
+ * struct sgx_pcmd - Paging Crypto Metadata (PCMD)
+ * @enclave_id: enclave identifier
+ * @mac: MAC over PCMD, page contents and isvsvn
+ *
+ * PCMD is stored for every swapped page to the regular memory. When ELDU loads
+ * the page back it recalculates the MAC by using a isvsvn number stored in a
+ * VA page. Together these two structures bring integrity and rollback
+ * protection.
+ */
+struct sgx_pcmd {
+ struct sgx_secinfo secinfo;
+ u64 enclave_id;
+ u8 reserved[SGX_PCMD_RESERVED_SIZE];
+ u8 mac[16];
+} __packed __aligned(128);
+
+#define SGX_SIGSTRUCT_RESERVED1_SIZE 84
+#define SGX_SIGSTRUCT_RESERVED2_SIZE 20
+#define SGX_SIGSTRUCT_RESERVED3_SIZE 32
+#define SGX_SIGSTRUCT_RESERVED4_SIZE 12
+
+/**
+ * struct sgx_sigstruct - an enclave signature
+ * @header1: a constant byte string
+ * @vendor: must be either 0x0000 or 0x8086
+ * @date: YYYYMMDD in BCD
+ * @header2: a costant byte string
+ * @application: an application defined value
+ * @modulus: the modulus of the public key
+ * @exponent: the exponent of the public key
+ * @signature: the signature calculated over the fields except modulus,
+ * exponent, signature, reserved4, q1 and q2
+ * @miscselect: additional information stored to an SSA frame
+ * @misc_mask: required miscselect in SECS
+ * @attributes: attributes for enclave
+ * @xfrm: XSave-Feature Request Mask (subset of XCR0)
+ * @attributes_mask: required attributes in SECS
+ * @xfrm_mask: required XFRM in SECS
+ * @mrenclave: SHA256-hash of the enclave contents
+ * @isvprodid: a user-defined value that is used in key derivation
+ * @isvsvn: a user-defined value that is used in key derivation
+ * @q1: a value used in RSA signature verification
+ * @q2: a value used in RSA signature verification
+ */
+struct sgx_sigstruct {
+ u64 header1[2];
+ u32 vendor;
+ u32 date;
+ u64 header2[2];
+ u32 application;
+ u8 reserved1[SGX_SIGSTRUCT_RESERVED1_SIZE];
+ u8 modulus[SGX_MODULUS_SIZE];
+ u32 exponent;
+ u8 signature[SGX_MODULUS_SIZE];
+ u32 miscselect;
+ u32 misc_mask;
+ u8 reserved2[SGX_SIGSTRUCT_RESERVED2_SIZE];
+ u64 attributes;
+ u64 xfrm;
+ u64 attributes_mask;
+ u64 xfrm_mask;
+ u8 mrenclave[32];
+ u8 reserved3[SGX_SIGSTRUCT_RESERVED3_SIZE];
+ u16 isvprodid;
+ u16 isvsvn;
+ u8 reserved4[SGX_SIGSTRUCT_RESERVED4_SIZE];
+ u8 q1[SGX_MODULUS_SIZE];
+ u8 q2[SGX_MODULUS_SIZE];
+} __packed __aligned(4096);
+
+#define SGX_EINITTOKEN_RESERVED1_SIZE 11
+#define SGX_EINITTOKEN_RESERVED2_SIZE 32
+#define SGX_EINITTOKEN_RESERVED3_SIZE 32
+#define SGX_EINITTOKEN_RESERVED4_SIZE 24
+
+/**
+ * struct sgx_einittoken - a token permitting to launch an enclave
+ * @valid: one if valid and zero if invalid
+ * @attributes: attributes for enclave
+ * @xfrm: XSave-Feature Request Mask (subset of XCR0)
+ * @mrenclave: SHA256-hash of the enclave contents
+ * @mrsigner: SHA256-hash of the public key used to sign the
+ * SIGSTRUCT
+ * @le_cpusvn: a value that reflects the SGX implementation
+ * running in in the CPU
+ * @le_isvprodid: a user-defined value that is used in key
+ * derivation
+ * @le_isvsvn: a user-defined value that is used in key
+ * derivation
+ * @le_keyed_miscselect: LE's miscselect masked with the token keys
+ * miscselect
+ * @le_keyed_attributes: LE's attributes masked with the token keys
+ * attributes
+ * @le_keyed_xfrm: LE's XFRM masked with the token keys xfrm
+ * @salt: random salt for wear-out protection
+ * @mac: CMAC over the preceding fields
+ *
+ * An enclave with EINITTOKENKEY attribute can access a key with the same name
+ * by using ENCLS(EGETKEY) and use this to sign cryptographic tokens that can
+ * be passed to ENCLS(EINIT) to permit the launch of other enclaves. This is
+ * the only viable way to launch enclaves if IA32_SGXLEPUBKEYHASHn MSRs are
+ * locked assuming that there is a Launch Enclave (LE) available that can be
+ * used for generating these tokens.
+ */
+struct sgx_einittoken {
+ u32 valid;
+ u32 reserved1[SGX_EINITTOKEN_RESERVED1_SIZE];
+ u64 attributes;
+ u64 xfrm;
+ u8 mrenclave[32];
+ u8 reserved2[SGX_EINITTOKEN_RESERVED2_SIZE];
+ u8 mrsigner[32];
+ u8 reserved3[SGX_EINITTOKEN_RESERVED3_SIZE];
+ u8 le_cpusvn[16];
+ u16 le_isvprodid;
+ u16 le_isvsvn;
+ u8 reserved4[SGX_EINITTOKEN_RESERVED4_SIZE];
+ u32 le_keyed_miscselect;
+ u64 le_keyed_attributes;
+ u64 le_keyed_xfrm;
+ u8 salt[32];
+ u8 mac[16];
+} __packed __aligned(512);
+
#endif /* _ASM_X86_SGX_ARCH_H */
--
2.19.1
SGX defines its own CPUID leaf, 0x12, along with a variable number of
sub-leafs. Sub-leafs 0 and 1 are always available if SGX is supported
and enumerate various SGX features, e.g. instruction sets and enclave
capabilities. Sub-leafs 2+ are variable, both in their existence and
in what they enumerate. Bits 3:0 of EAX report the sub-leaf type,
with the remaining bits in EAX, EBX, ECX and EDX being type-specific.
Currently, the only known sub-leaf type enumerates an EPC section. An
EPC section is simply a range of EPC memory available to software.
The "list" of varaible SGX sub-leafs is NULL-terminated, i.e. software
is expected to query CPUID until an invalid sub-leaf is encountered.
Co-developed-by: Sean Christopherson <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
arch/x86/include/asm/sgx_arch.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/arch/x86/include/asm/sgx_arch.h b/arch/x86/include/asm/sgx_arch.h
index d4c57154e6e6..29c37971e8b3 100644
--- a/arch/x86/include/asm/sgx_arch.h
+++ b/arch/x86/include/asm/sgx_arch.h
@@ -11,6 +11,21 @@
#include <linux/types.h>
#include <uapi/asm/sgx_errno.h>
+#define SGX_CPUID 0x12
+#define SGX_CPUID_FIRST_VARIABLE_SUB_LEAF 2
+
+/**
+ * enum sgx_sub_leaf_types - SGX CPUID variable sub-leaf types
+ * %SGX_CPUID_SUB_LEAF_INVALID: Indicates this sub-leaf is invalid.
+ * %SGX_CPUID_SUB_LEAF_EPC_SECTION: Sub-leaf enumerates an EPC section.
+ * %SGX_CPUID_SUB_LEAF_TYPE_MASK: Mask for bits containing the type.
+ */
+enum sgx_sub_leaf_types {
+ SGX_CPUID_SUB_LEAF_INVALID = 0x0,
+ SGX_CPUID_SUB_LEAF_EPC_SECTION = 0x1,
+ SGX_CPUID_SUB_LEAF_TYPE_MASK = 0xF,
+};
+
/**
* enum sgx_encls_leaves - ENCLS leaf functions
* %SGX_ECREATE: Create an enclave.
--
2.19.1
From: Kai Huang <[email protected]>
X86_FEATURE_SGX_LC reflects whether or not the CPU supports SGX Launch
Control, i.e. enumerates the existence of IA32_FEATURE_CONTROL's
SGX_LE_WR bit and the IA32_SGXLEPUBKEYHASH MSRs.
Signed-off-by: Kai Huang <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/include/asm/cpufeatures.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 1b8dea9a06cb..1213e68f87e7 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -341,6 +341,7 @@
#define X86_FEATURE_LA57 (16*32+16) /* 5-level page tables */
#define X86_FEATURE_RDPID (16*32+22) /* RDPID instruction */
#define X86_FEATURE_CLDEMOTE (16*32+25) /* CLDEMOTE instruction */
+#define X86_FEATURE_SGX_LC (16*32+30) /* Software Guard Extensions Launch Control */
/* AMD-defined CPU features, CPUID level 0x80000007 (EBX), word 17 */
#define X86_FEATURE_OVERFLOW_RECOV (17*32+ 0) /* MCA overflow recovery support */
--
2.19.1
From: Sean Christopherson <[email protected]>
Like SGX itself, SGX Launch Control must be explicitly enabled via a
flag in IA32_FEATURE_CONTROL. Clear the SGX_LC capability if Launch
Control is not fully enabled (or obviously if SGX itself is disabled).
Note that clearing X86_FEATURE_SGX_LC creates a bit of a conundrum
regarding the SGXLEPUBKEYHASH MSRs, as it may be desirable to read the
MSRs even if they are not writable, e.g. to query the configured key,
but clearing the capability leaves no breadcrum for discerning whether
or not the MSRs exist. But, such usage will be rare (KVM is the only
known case at this time) and not performance critical, so it's not
unreasonable to require the use of rdmsr_safe(). Clearing the cap bit
eliminates the need for an additional flag to track whether or not
Launch Control is truly enabled, which is what we care about the vast
majority of the time.
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/kernel/cpu/intel.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 9bf8fe2c04ac..bc52c52f7025 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -618,6 +618,8 @@ static void detect_sgx(struct cpuinfo_x86 *c)
setup_clear_cpu_cap(X86_FEATURE_SGX1);
setup_clear_cpu_cap(X86_FEATURE_SGX2);
}
+ if (unsupported || !(fc & FEATURE_CONTROL_SGX_LE_WR))
+ setup_clear_cpu_cap(X86_FEATURE_SGX_LC);
}
static void init_intel_energy_perf(struct cpuinfo_x86 *c)
--
2.19.1
The SGX architecture defines an extensive set of error codes that are
used by ENCL{S,U,V} instructions to provide software with (somewhat)
precise error information. Though they are architectural, define the
known error codes in a separate file from sgx_arch.h so that they can
be exposed to userspace. For some ENCLS leafs, e.g. EINIT, returning
the exact error code on failure can enable userspace to make informed
decisions when an operation fails.
Co-developed-by: Sean Christopherson <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
arch/x86/include/asm/sgx_arch.h | 2 +
arch/x86/include/uapi/asm/sgx_errno.h | 91 +++++++++++++++++++++++++++
2 files changed, 93 insertions(+)
create mode 100644 arch/x86/include/uapi/asm/sgx_errno.h
diff --git a/arch/x86/include/asm/sgx_arch.h b/arch/x86/include/asm/sgx_arch.h
index e068db46835e..6cd572fa95fa 100644
--- a/arch/x86/include/asm/sgx_arch.h
+++ b/arch/x86/include/asm/sgx_arch.h
@@ -8,6 +8,8 @@
#ifndef _ASM_X86_SGX_ARCH_H
#define _ASM_X86_SGX_ARCH_H
+#include <uapi/asm/sgx_errno.h>
+
/**
* enum sgx_encls_leaves - ENCLS leaf functions
* %SGX_ECREATE: Create an enclave.
diff --git a/arch/x86/include/uapi/asm/sgx_errno.h b/arch/x86/include/uapi/asm/sgx_errno.h
new file mode 100644
index 000000000000..48b87aed58d7
--- /dev/null
+++ b/arch/x86/include/uapi/asm/sgx_errno.h
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
+/*
+ * Copyright(c) 2018 Intel Corporation.
+ *
+ * Contains the architecturally defined error codes that are returned by SGX
+ * instructions, e.g. ENCLS, and may be propagated to userspace via errno.
+ */
+
+#ifndef _UAPI_ASM_X86_SGX_ERRNO_H
+#define _UAPI_ASM_X86_SGX_ERRNO_H
+
+/**
+ * enum sgx_encls_leaves - return codes for ENCLS, ENCLU and ENCLV
+ * %SGX_SUCCESS: No error.
+ * %SGX_INVALID_SIG_STRUCT: SIGSTRUCT contains an invalid value.
+ * %SGX_INVALID_ATTRIBUTE: Enclave is not attempting to access a resource
+ * for which it is not authorized.
+ * %SGX_BLKSTATE: EPC page is already blocked.
+ * %SGX_INVALID_MEASUREMENT: SIGSTRUCT or EINITTOKEN contains an incorrect
+ * measurement.
+ * %SGX_NOTBLOCKABLE: EPC page type is not one which can be blocked.
+ * %SGX_PG_INVLD: EPC page is invalid (and cannot be blocked).
+ * %SGX_EPC_PAGE_CONFLICT: EPC page in use by another SGX instruction.
+ * %SGX_INVALID_SIGNATURE: Enclave's signature does not validate with
+ * public key enclosed in SIGSTRUCT.
+ * %SGX_MAC_COMPARE_FAIL: MAC check failed when reloading EPC page.
+ * %SGX_PAGE_NOT_BLOCKED: EPC page is not marked as blocked.
+ * %SGX_NOT_TRACKED: ETRACK has not been completed on the EPC page.
+ * %SGX_VA_SLOT_OCCUPIED: Version array slot contains a valid entry.
+ * %SGX_CHILD_PRESENT: Enclave has child pages present in the EPC.
+ * %SGX_ENCLAVE_ACT: Logical processors are currently executing
+ * inside the enclave.
+ * %SGX_ENTRYEPOCH_LOCKED: SECS locked for EPOCH update, i.e. an ETRACK is
+ * currently executing on the SECS.
+ * %SGX_INVALID_EINITTOKEN: EINITTOKEN is invalid and enclave signer's
+ * public key does not match IA32_SGXLEPUBKEYHASH.
+ * %SGX_PREV_TRK_INCMPL: All processors did not complete the previous
+ * tracking sequence.
+ * %SGX_PG_IS_SECS: Target EPC page is an SECS and cannot be
+ * blocked.
+ * %SGX_PAGE_ATTRIBUTES_MISMATCH: Attributes of the EPC page do not match
+ * the expected values.
+ * %SGX_PAGE_NOT_MODIFIABLE: EPC page cannot be modified because it is in
+ * the PENDING or MODIFIED state.
+ * %SGX_PAGE_NOT_DEBUGGABLE: EPC page cannot be modified because it is in
+ * the PENDING or MODIFIED state.
+ * %SGX_INVALID_COUNTER: {In,De}crementing a counter would cause it to
+ * {over,under}flow.
+ * %SGX_PG_NONEPC: Target page is not an EPC page.
+ * %SGX_TRACK_NOT_REQUIRED: Target page type does not require tracking.
+ * %SGX_INVALID_CPUSVN: Security version number reported by CPU is less
+ * than what is required by the enclave.
+ * %SGX_INVALID_ISVSVN: Security version number of enclave is less than
+ * what is required by the KEYREQUEST struct.
+ * %SGX_UNMASKED_EVENT: An unmasked event, e.g. INTR, was received
+ * while the instruction was executing.
+ * %SGX_INVALID_KEYNAME: Requested key is not supported by hardware.
+ */
+enum sgx_return_codes {
+ SGX_SUCCESS = 0,
+ SGX_INVALID_SIG_STRUCT = 1,
+ SGX_INVALID_ATTRIBUTE = 2,
+ SGX_BLKSTATE = 3,
+ SGX_INVALID_MEASUREMENT = 4,
+ SGX_NOTBLOCKABLE = 5,
+ SGX_PG_INVLD = 6,
+ SGX_EPC_PAGE_CONFLICT = 7,
+ SGX_INVALID_SIGNATURE = 8,
+ SGX_MAC_COMPARE_FAIL = 9,
+ SGX_PAGE_NOT_BLOCKED = 10,
+ SGX_NOT_TRACKED = 11,
+ SGX_VA_SLOT_OCCUPIED = 12,
+ SGX_CHILD_PRESENT = 13,
+ SGX_ENCLAVE_ACT = 14,
+ SGX_ENTRYEPOCH_LOCKED = 15,
+ SGX_INVALID_EINITTOKEN = 16,
+ SGX_PREV_TRK_INCMPL = 17,
+ SGX_PG_IS_SECS = 18,
+ SGX_PAGE_ATTRIBUTES_MISMATCH = 19,
+ SGX_PAGE_NOT_MODIFIABLE = 20,
+ SGX_PAGE_NOT_DEBUGGABLE = 21,
+ SGX_INVALID_COUNTER = 25,
+ SGX_PG_NONEPC = 26,
+ SGX_TRACK_NOT_REQUIRED = 27,
+ SGX_INVALID_CPUSVN = 32,
+ SGX_INVALID_ISVSVN = 64,
+ SGX_UNMASKED_EVENT = 128,
+ SGX_INVALID_KEYNAME = 256,
+};
+
+#endif /* _UAPI_ASM_X86_SGX_ERRNO_H */
--
2.19.1
At this time there is no support for reclaiming pages prior to the
owner explicitly freeing the page. As for freeing pages, because
freeing a page is expected to succeed in the vast majority of cases
and because most call sites will not be equipped to handle failure,
provide a variant for freeing a page that warns on failure, e.g. due
to ENCLS[EREMOVE] failing.
Co-developed-by: Sean Christopherson <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
arch/x86/include/asm/sgx.h | 4 ++
arch/x86/kernel/cpu/intel_sgx.c | 77 +++++++++++++++++++++++++++++++++
2 files changed, 81 insertions(+)
diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index aa51165eb3a8..4e39bcfad018 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -309,4 +309,8 @@ static inline int __emodt(struct sgx_secinfo *secinfo, void __iomem *addr)
return __encls_ret_2(SGX_EMODT, secinfo, addr);
}
+struct sgx_epc_page *sgx_alloc_page(void);
+int __sgx_free_page(struct sgx_epc_page *page);
+void sgx_free_page(struct sgx_epc_page *page);
+
#endif /* _ASM_X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/intel_sgx.c b/arch/x86/kernel/cpu/intel_sgx.c
index b86aa4111592..b06709a9ea65 100644
--- a/arch/x86/kernel/cpu/intel_sgx.c
+++ b/arch/x86/kernel/cpu/intel_sgx.c
@@ -15,6 +15,83 @@ EXPORT_SYMBOL_GPL(sgx_epc_sections);
static int sgx_nr_epc_sections;
+/**
+ * sgx_alloc_page - Allocate an EPC page
+ *
+ * Try to grab a page from the free EPC page list.
+ *
+ * Return:
+ * a pointer to a &struct sgx_epc_page instance,
+ * -errno on error
+ */
+struct sgx_epc_page *sgx_alloc_page(void)
+{
+ struct sgx_epc_section *section;
+ struct sgx_epc_page *page;
+ int i;
+
+ for (i = 0; i < sgx_nr_epc_sections; i++) {
+ section = &sgx_epc_sections[i];
+ spin_lock(§ion->lock);
+ if (section->free_cnt) {
+ page = section->pages[section->free_cnt - 1];
+ section->free_cnt--;
+ }
+ spin_unlock(§ion->lock);
+
+ if (page)
+ return page;
+ }
+
+ return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL_GPL(sgx_alloc_page);
+
+/**
+ * __sgx_free_page - Free an EPC page
+ * @page: pointer a previously allocated EPC page
+ *
+ * EREMOVE an EPC page and insert it back to the list of free pages.
+ *
+ * Return:
+ * 0 on success
+ * SGX error code if EREMOVE fails
+ */
+int __sgx_free_page(struct sgx_epc_page *page)
+{
+ struct sgx_epc_section *section = sgx_epc_section(page);
+ int ret;
+
+ ret = __eremove(sgx_epc_addr(page));
+ if (ret)
+ return ret;
+
+ spin_lock(§ion->lock);
+ section->pages[section->free_cnt++] = page;
+ spin_unlock(§ion->lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__sgx_free_page);
+
+/**
+ * sgx_free_page - Free an EPC page and WARN on failure
+ * @page: pointer to a previously allocated EPC page
+ *
+ * EREMOVE an EPC page and insert it back to the list of free pages, and WARN
+ * if EREMOVE fails. For use when the call site cannot (or chooses not to)
+ * handle failure, i.e. the page is leaked on failure.
+ */
+void sgx_free_page(struct sgx_epc_page *page)
+{
+ int ret;
+
+ ret = __sgx_free_page(page);
+ WARN(ret > 0, "sgx: EREMOVE returned %d (0x%x)", ret, ret);
+}
+EXPORT_SYMBOL_GPL(sgx_free_page);
+
+
static __init void sgx_free_epc_section(struct sgx_epc_section *section)
{
int i;
--
2.19.1
ENCLS is an umbrella instruction for a variety of cpl0 SGX functions.
The ENCLS function that is executed is specified in EAX, with each
function potentially having more leaf-specific operands beyond EAX.
ENCLS introduces its own (positive value) error codes that (some)
leafs use to return failure information in EAX. Leafs that return
an error code also modify RFLAGS. And finally, ENCLS generates
ENCLS-specific non-fatal #GPs and #PFs, i.e. a bug-free kernel may
encounter faults on ENCLS that must be handled gracefully.
Because of the complexity involved in encoding ENCLS and handling its
assortment of failure paths, executing any given leaf is not a simple
matter of emitting ENCLS.
To enable adding support for ENCLS leafs with minimal fuss, add a
two-layer macro system along with an encoding scheme to allow wrappers
to return trap numbers along ENCLS-specific error codes. The bottom
layer of the macro system splits between the leafs that return an
error code and those that do not. The second layer generates the
correct input/output annotations based on the number of operands for
each leaf function.
Co-developed-by: Sean Christopherson <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
arch/x86/include/asm/sgx.h | 255 +++++++++++++++++++++++++++++++++++++
1 file changed, 255 insertions(+)
create mode 100644 arch/x86/include/asm/sgx.h
diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
new file mode 100644
index 000000000000..23361d508348
--- /dev/null
+++ b/arch/x86/include/asm/sgx.h
@@ -0,0 +1,255 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/**
+ * Copyright(c) 2016-18 Intel Corporation.
+ */
+#ifndef _ASM_X86_SGX_H
+#define _ASM_X86_SGX_H
+
+#include <asm/asm.h>
+#include <asm/sgx_arch.h>
+
+/**
+ * ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
+ *
+ * ENCLS has its own (positive value) error codes and also generates
+ * ENCLS specific #GP and #PF faults. And the ENCLS values get munged
+ * with system error codes as everything percolates back up the stack.
+ * Unfortunately (for us), we need to precisely identify each unique
+ * error code, e.g. the action taken if EWB fails varies based on the
+ * type of fault and on the exact SGX error code, i.e. we can't simply
+ * convert all faults to -EFAULT.
+ *
+ * To make all three error types coexist, we set bit 30 to identify an
+ * ENCLS fault. Bit 31 (technically bits N:31) is used to differentiate
+ * between positive (faults and SGX error codes) and negative (system
+ * error codes) values.
+ */
+#define ENCLS_FAULT_FLAG 0x40000000
+
+/**
+ * Check for a fault by looking for a postive value with the fault
+ * flag set. The postive value check is needed to filter out system
+ * error codes since negative values will have all higher order bits
+ * set, including ENCLS_FAULT_FLAG.
+ */
+#define IS_ENCLS_FAULT(r) ((int)(r) > 0 && ((r) & ENCLS_FAULT_FLAG))
+
+/**
+ * Retrieve the encoded trapnr from the specified return code.
+ */
+#define ENCLS_TRAPNR(r) ((r) & ~ENCLS_FAULT_FLAG)
+
+/**
+ * encls_to_err - translate an ENCLS fault or SGX code into a system error code
+ * @ret: positive value return code
+ *
+ * Translate a postive return code, e.g. from ENCLS, into a system error
+ * code. Primarily used by functions that cannot return a non-negative
+ * error code, e.g. kernel callbacks.
+ *
+ * Return:
+ * 0 on success,
+ * -errno on failure
+ */
+static inline int encls_to_err(int ret)
+{
+ if (IS_ENCLS_FAULT(ret))
+ return -EFAULT;
+
+ switch (ret) {
+ case SGX_UNMASKED_EVENT:
+ return -EINTR;
+ case SGX_INVALID_SIG_STRUCT:
+ case SGX_INVALID_ATTRIBUTE:
+ case SGX_INVALID_MEASUREMENT:
+ case SGX_INVALID_EINITTOKEN:
+ case SGX_INVALID_CPUSVN:
+ case SGX_INVALID_ISVSVN:
+ case SGX_INVALID_KEYNAME:
+ return -EINVAL;
+ case SGX_ENCLAVE_ACT:
+ case SGX_CHILD_PRESENT:
+ case SGX_ENTRYEPOCH_LOCKED:
+ case SGX_PREV_TRK_INCMPL:
+ case SGX_PAGE_NOT_MODIFIABLE:
+ case SGX_PAGE_NOT_DEBUGGABLE:
+ return -EBUSY;
+ default:
+ return -EIO;
+ };
+}
+
+/**
+ * __encls_ret_N - encode an ENCLS leaf that returns an error code in EAX
+ * @rax: leaf number
+ * @inputs: asm inputs for the leaf
+ *
+ * Emit assembly for an ENCLS leaf that returns an error code, e.g. EREMOVE.
+ * And because SGX isn't complex enough as it is, leafs that return an error
+ * code also modify flags.
+ *
+ * Return:
+ * 0 on success,
+ * SGX error code on failure
+ */
+#define __encls_ret_N(rax, inputs...) \
+ ({ \
+ int ret; \
+ asm volatile( \
+ "1: .byte 0x0f, 0x01, 0xcf;\n\t" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \
+ " jmp 2b\n" \
+ ".previous\n" \
+ _ASM_EXTABLE_FAULT(1b, 3b) \
+ : "=a"(ret) \
+ : "a"(rax), inputs \
+ : "memory", "cc"); \
+ ret; \
+ })
+
+#define __encls_ret_1(rax, rcx) \
+ ({ \
+ __encls_ret_N(rax, "c"(rcx)); \
+ })
+
+#define __encls_ret_2(rax, rbx, rcx) \
+ ({ \
+ __encls_ret_N(rax, "b"(rbx), "c"(rcx)); \
+ })
+
+#define __encls_ret_3(rax, rbx, rcx, rdx) \
+ ({ \
+ __encls_ret_N(rax, "b"(rbx), "c"(rcx), "d"(rdx)); \
+ })
+
+/**
+ * __encls_N - encode an ENCLS leaf that doesn't return an error code
+ * @rax: leaf number
+ * @rbx_out: optional output variable
+ * @inputs: asm inputs for the leaf
+ *
+ * Emit assembly for an ENCLS leaf that does not return an error code,
+ * e.g. ECREATE. Leaves without error codes either succeed or fault.
+ * @rbx_out is an optional parameter for use by EDGBRD, which returns
+ * the the requested value in RBX.
+ *
+ * Return:
+ * 0 on success,
+ * trapnr with ENCLS_FAULT_FLAG set on fault
+ */
+#define __encls_N(rax, rbx_out, inputs...) \
+ ({ \
+ int ret; \
+ asm volatile( \
+ "1: .byte 0x0f, 0x01, 0xcf;\n\t" \
+ " xor %%eax,%%eax;\n" \
+ "2:\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \
+ " jmp 2b\n" \
+ ".previous\n" \
+ _ASM_EXTABLE_FAULT(1b, 3b) \
+ : "=a"(ret), "=b"(rbx_out) \
+ : "a"(rax), inputs \
+ : "memory"); \
+ ret; \
+ })
+
+#define __encls_2(rax, rbx, rcx) \
+ ({ \
+ unsigned long ign_rbx_out; \
+ __encls_N(rax, ign_rbx_out, "b"(rbx), "c"(rcx)); \
+ })
+
+#define __encls_1_1(rax, data, rcx) \
+ ({ \
+ unsigned long rbx_out; \
+ int ret = __encls_N(rax, rbx_out, "c"(rcx)); \
+ if (!ret) \
+ data = rbx_out; \
+ ret; \
+ })
+
+static inline int __ecreate(struct sgx_pageinfo *pginfo, void __iomem *secs)
+{
+ return __encls_2(SGX_ECREATE, pginfo, secs);
+}
+
+static inline int __eextend(void __iomem *secs, void __iomem *addr)
+{
+ return __encls_2(SGX_EEXTEND, secs, addr);
+}
+
+static inline int __eadd(struct sgx_pageinfo *pginfo, void __iomem *addr)
+{
+ return __encls_2(SGX_EADD, pginfo, addr);
+}
+
+static inline int __einit(void *sigstruct, struct sgx_einittoken *einittoken,
+ void __iomem *secs)
+{
+ return __encls_ret_3(SGX_EINIT, sigstruct, secs, einittoken);
+}
+
+static inline int __eremove(void __iomem *addr)
+{
+ return __encls_ret_1(SGX_EREMOVE, addr);
+}
+
+static inline int __edbgwr(void __iomem *addr, unsigned long *data)
+{
+ return __encls_2(SGX_EDGBWR, *data, addr);
+}
+
+static inline int __edbgrd(void __iomem *addr, unsigned long *data)
+{
+ return __encls_1_1(SGX_EDGBRD, *data, addr);
+}
+
+static inline int __etrack(void __iomem *addr)
+{
+ return __encls_ret_1(SGX_ETRACK, addr);
+}
+
+static inline int __eldu(struct sgx_pageinfo *pginfo, void __iomem *addr,
+ void *va)
+{
+ return __encls_ret_3(SGX_ELDU, pginfo, addr, va);
+}
+
+static inline int __eblock(void __iomem *addr)
+{
+ return __encls_ret_1(SGX_EBLOCK, addr);
+}
+
+static inline int __epa(void __iomem *addr)
+{
+ unsigned long rbx = SGX_PAGE_TYPE_VA;
+
+ return __encls_2(SGX_EPA, rbx, addr);
+}
+
+static inline int __ewb(struct sgx_pageinfo *pginfo, void __iomem *addr,
+ void __iomem *va)
+{
+ return __encls_ret_3(SGX_EWB, pginfo, addr, va);
+}
+
+static inline int __eaug(struct sgx_pageinfo *pginfo, void __iomem *addr)
+{
+ return __encls_2(SGX_EAUG, pginfo, addr);
+}
+
+static inline int __emodpr(struct sgx_secinfo *secinfo, void __iomem *addr)
+{
+ return __encls_ret_2(SGX_EMODPR, secinfo, addr);
+}
+
+static inline int __emodt(struct sgx_secinfo *secinfo, void __iomem *addr)
+{
+ return __encls_ret_2(SGX_EMODT, secinfo, addr);
+}
+
+#endif /* _ASM_X86_SGX_H */
--
2.19.1
From: Sean Christopherson <[email protected]>
Add a new IA32_FEATURE_CONTROL bit, SGX_LE_WR. When set, SGX_LE_WR
allows software to write the SGXLEPUBKEYHASH MSRs (see below). The
The existence of the bit is enumerated by CPUID as X86_FEATURE_SGX_LC.
Like all other flags in IA32_FEATURE_CONTROL, the MSR must be locked
for SGX_LE_WR to take effect.
Add four MSRs, SGXLEPUBKEYHASH{0,1,2,3}, or in human readable form,
the SGX Launch Enclave Public Key Hash MSRs. These MSRs correspond to
the key that is used by the CPU to determine whether or not to allow
software to enter an enclave. When ENCLS[EINIT] is executed, which is
a prerequisite to entering the enclave, the CPU compares the key
(technically its hash) used to sign the enclave with the key hash
stored in the MSRs, and will reject EINIT if the keys do not match.
Enclaves can also be blessed by proxy, in which case a Launch Enclave
generates and signs an EINIT TOKEN. If a valid token is provided,
ENCLS[EINIT] compares the signer of the token against the MSRs instead
of the signer of the enclave. The SGXLEPUBKEYHASH MSRs only exist on
CPUs that support SGX Launch Control, enumerated by X86_FEATURE_SGX_LC.
CPUs without Launch Control use a hardcoded key for the ENCLS[EINIT]
checks. An internal hardcoded key is also used as the reset value for
the hash MSRs when they exist.
As a final note, the SGX_LEPUBKEYHASH MSRs can also be written by
pre-boot firmware prior to activating SGX (SGX activation is done by
setting bit 0 in MSR 0x7A). Thus, firmware can lock the MSRs to a
non-Intel value by writing the MSRs and locking IA32_FEATURE_CONTROL
without setting SGX_LE_WR.
Co-developed-by: Haim Cohen <[email protected]>
Signed-off-by: Haim Cohen <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/include/asm/msr-index.h | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 2837f65ac817..ffae9df1c0ab 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -486,6 +486,7 @@
#define FEATURE_CONTROL_LOCKED (1<<0)
#define FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX (1<<1)
#define FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX (1<<2)
+#define FEATURE_CONTROL_SGX_LE_WR (1<<17)
#define FEATURE_CONTROL_SGX_ENABLE (1<<18)
#define FEATURE_CONTROL_LMCE (1<<20)
@@ -499,6 +500,12 @@
#define MSR_IA32_UCODE_WRITE 0x00000079
#define MSR_IA32_UCODE_REV 0x0000008b
+/* Intel SGX Launch Enclave Public Key Hash MSRs */
+#define MSR_IA32_SGXLEPUBKEYHASH0 0x0000008C
+#define MSR_IA32_SGXLEPUBKEYHASH1 0x0000008D
+#define MSR_IA32_SGXLEPUBKEYHASH2 0x0000008E
+#define MSR_IA32_SGXLEPUBKEYHASH3 0x0000008F
+
#define MSR_IA32_SMM_MONITOR_CTL 0x0000009b
#define MSR_IA32_SMBASE 0x0000009e
--
2.19.1
Because the kernel is untrusted, swapping pages in/out of the Enclave
Page Cache (EPC) has specialized requirements:
* The kernel cannot directly access EPC memory, i.e. cannot copy data
to/from the EPC.
* To evict a page from the EPC, the kernel must "prove" to hardware that
are no valid TLB entries for said page since a stale TLB entry would
allow an attacker to bypass SGX access controls.
* When loading a page back into the EPC, hardware must be able to verify
the integrity and freshness of the data.
* When loading an enclave page, e.g. regular pages and Thread Control
Structures (TCS), hardware must be able to associate the page with a
Secure Enclave Control Structure (SECS).
To satisfy the above requirements, the CPU provides dedicated ENCLS
functions to support paging data in/out of the EPC:
* EBLOCK: Mark a page as blocked in the EPC Map (EPCM). Attempting
to access a blocked page that misses the TLB will fault.
* ETRACK: Activate blocking tracking. Hardware verifies that all
translations for pages marked as "blocked" have been flushed
from the TLB.
* EPA: Add version array page to the EPC. As the name suggests, a
VA page is an 512-entry array of version numbers that are
used to uniquely identify pages evicted from the EPC.
* EWB: Write back a page from EPC to memory, e.g. RAM. Software
must supply a VA slot, memory to hold the a Paging Crypto
Metadata (PCMD) of the page and obviously backing for the
evicted page.
* ELD{B,U}: Load a page in {un}blocked state from memory to EPC. The
driver only uses the ELDU variant as there is no use case
for loading a page as "blocked" in a bare metal environment.
To top things off, all of the above ENCLS functions are subject to
strict concurrency rules, e.g. many operations will #GP fault if two
or more operations attempt to access common pages/structures.
To put it succinctly, paging in/out of the EPC requires coordinating
with the SGX driver where all of an enclave's tracking resides. But,
simply shoving all reclaim logic into the driver is not desirable as
doing so has unwanted long term implications:
* Oversubscribing EPC to KVM guests, i.e. virtualizing SGX in KVM and
swapping a guest's EPC pages (without the guest's cooperation) needs
the same high level flows for reclaim but has painfully different
semantics in the details.
* Accounting EPC, i.e. adding an EPC cgroup controller, is desirable
as EPC is effectively a specialized memory type and even more scarce
than system memory. Providing a single touchpoint for EPC accounting
regardless of end consumer greatly simplifies the EPC controller.
* Allowing the userspace-facing driver to be built as a loaded module
is desirable, e.g. for debug, testing and development. The cgroup
infrastructure does not support dependencies on loadable modules.
* Separating EPC swapping from the driver once it has been tightly
coupled to the driver is non-trivial (speaking from experience).
So, although the SGX driver is currently the sole consumer of EPC,
encapsulate EPC swapping in the driver to minimize the dependencies
between the core SGX code and driver, and do so in a way that can be
extended to an abstracted interface with minimal effort.
To that end, add functions to swap EPC pages to the driver. The user
of these functions will be the core SGX subsystem, which will be enabled
in a future patch.
* sgx_encl_page_{get,put}() - Attempt to pin/unpin (the owner of) an EPC
page so that it can be operated on by a reclaimer.
* sgx_encl_page_reclaim() - Mark a page as being reclaimed. The
page is considered reclaimable if it hasn't been accessed recently and
it isn't reserved by the driver for other use.
* sgx_encl_page_block() - EBLOCK an EPC page
* sgx_encl_page_write() - Evict an EPC page to the regular memory via
EWB. Activates ETRACK (via sgx_encl_track()) if necessary.
Since we also need to be able to fault pages back into the EPC, add a
page fault handler to allocate an EPC page and ELDU a previously evicted
page.
Signed-off-by: Jarkko Sakkinen <[email protected]>
Co-developed-by: Sean Christopherson <[email protected]>
Co-developed-by: Serge Ayoun <[email protected]>
Co-developed-by: Shay Katz-zamir <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Serge Ayoun <[email protected]>
Signed-off-by: Shay Katz-zamir <[email protected]>
---
drivers/platform/x86/intel_sgx/Makefile | 2 +
drivers/platform/x86/intel_sgx/sgx.h | 32 +++
drivers/platform/x86/intel_sgx/sgx_encl.c | 194 +++++++++++++++++-
.../platform/x86/intel_sgx/sgx_encl_page.c | 179 ++++++++++++++++
drivers/platform/x86/intel_sgx/sgx_fault.c | 108 ++++++++++
drivers/platform/x86/intel_sgx/sgx_util.c | 71 +++++++
drivers/platform/x86/intel_sgx/sgx_vma.c | 15 ++
7 files changed, 600 insertions(+), 1 deletion(-)
create mode 100644 drivers/platform/x86/intel_sgx/sgx_encl_page.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_fault.c
diff --git a/drivers/platform/x86/intel_sgx/Makefile b/drivers/platform/x86/intel_sgx/Makefile
index 117e97effeff..5023c5ebd57d 100644
--- a/drivers/platform/x86/intel_sgx/Makefile
+++ b/drivers/platform/x86/intel_sgx/Makefile
@@ -6,6 +6,8 @@ obj-$(CONFIG_INTEL_SGX) += intel_sgx.o
intel_sgx-$(CONFIG_INTEL_SGX) += \
sgx_encl.o \
+ sgx_encl_page.o \
+ sgx_fault.o \
sgx_ioctl.o \
sgx_main.o \
sgx_util.o \
diff --git a/drivers/platform/x86/intel_sgx/sgx.h b/drivers/platform/x86/intel_sgx/sgx.h
index 67bd8ea1d53d..f707701e422d 100644
--- a/drivers/platform/x86/intel_sgx/sgx.h
+++ b/drivers/platform/x86/intel_sgx/sgx.h
@@ -36,16 +36,32 @@
#define SGX_EINIT_SLEEP_COUNT 50
#define SGX_EINIT_SLEEP_TIME 20
+#define SGX_VA_SLOT_COUNT 512
+
+struct sgx_va_page {
+ struct sgx_epc_page *epc_page;
+ DECLARE_BITMAP(slots, SGX_VA_SLOT_COUNT);
+ struct list_head list;
+};
+
/**
* enum sgx_encl_page_desc - defines bits for an enclave page's descriptor
* %SGX_ENCL_PAGE_TCS: The page is a TCS page.
* %SGX_ENCL_PAGE_LOADED: The page is not swapped.
+ * %SGX_ENCL_PAGE_RESERVED: The page cannot be reclaimed.
+ * %SGX_ENCL_PAGE_RECLAIMED: The page is in the process of being
+ * reclaimed.
+ * %SGX_ENCL_PAGE_VA_OFFSET_MASK: Holds the offset in the Version Array
+ * (VA) page for a swapped page.
* %SGX_ENCL_PAGE_ADDR_MASK: Holds the virtual address of the page.
*/
enum sgx_encl_page_desc {
SGX_ENCL_PAGE_TCS = BIT(0),
SGX_ENCL_PAGE_LOADED = BIT(1),
/* Bits 11:3 are available when the page is not swapped. */
+ SGX_ENCL_PAGE_RESERVED = BIT(3),
+ SGX_ENCL_PAGE_RECLAIMED = BIT(4),
+ SGX_ENCL_PAGE_VA_OFFSET_MASK = GENMASK_ULL(11, 3),
SGX_ENCL_PAGE_ADDR_MASK = PAGE_MASK,
};
@@ -79,10 +95,12 @@ struct sgx_encl {
struct mutex lock;
struct mm_struct *mm;
struct file *backing;
+ struct file *pcmd;
struct kref refcount;
unsigned long base;
unsigned long size;
unsigned long ssaframesize;
+ struct list_head va_pages;
struct radix_tree_root page_tree;
struct list_head add_page_reqs;
struct work_struct add_page_work;
@@ -102,6 +120,16 @@ static inline pgoff_t sgx_encl_page_backing_index(struct sgx_encl_page *page,
return PFN_DOWN(page->desc - encl->base);
}
+static inline int sgx_encl_page_pcmd_offset(struct sgx_encl_page *page,
+ struct sgx_encl *encl)
+{
+ int index;
+
+ index = sgx_encl_page_backing_index(page, encl);
+ return (index & (PAGE_SIZE / sizeof(struct sgx_pcmd) - 1)) *
+ sizeof(struct sgx_pcmd);
+}
+
extern struct workqueue_struct *sgx_add_page_wq;
extern u64 sgx_encl_size_max_32;
extern u64 sgx_encl_size_max_64;
@@ -174,6 +202,10 @@ int sgx_test_and_clear_young(struct sgx_encl_page *page);
void sgx_flush_cpus(struct sgx_encl *encl);
void sgx_set_page_loaded(struct sgx_encl_page *encl_page,
struct sgx_epc_page *epc_page);
+struct sgx_epc_page *sgx_alloc_va_page(void);
+unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page);
+void sgx_free_va_slot(struct sgx_va_page *va_page, unsigned int offset);
+bool sgx_va_page_full(struct sgx_va_page *va_page);
struct page *sgx_get_backing(struct file *file, pgoff_t index);
void sgx_put_backing(struct page *backing_page, bool write);
diff --git a/drivers/platform/x86/intel_sgx/sgx_encl.c b/drivers/platform/x86/intel_sgx/sgx_encl.c
index 6bed944c2f92..1d0a51120e3d 100644
--- a/drivers/platform/x86/intel_sgx/sgx_encl.c
+++ b/drivers/platform/x86/intel_sgx/sgx_encl.c
@@ -53,6 +53,19 @@ int sgx_encl_find(struct mm_struct *mm, unsigned long addr,
return encl ? 0 : -ENOENT;
}
+static void sgx_free_va_pages(struct sgx_encl *encl)
+{
+ struct sgx_va_page *va_page;
+
+ while (!list_empty(&encl->va_pages)) {
+ va_page = list_first_entry(&encl->va_pages, struct sgx_va_page,
+ list);
+ list_del(&va_page->list);
+ sgx_free_page(va_page->epc_page);
+ kfree(va_page);
+ }
+}
+
/**
* sgx_invalidate - kill an enclave
* @encl: an &sgx_encl instance
@@ -88,7 +101,12 @@ void sgx_invalidate(struct sgx_encl *encl, bool flush_cpus)
}
radix_tree_for_each_slot(slot, &encl->page_tree, &iter, 0) {
entry = *slot;
- if (entry->desc & SGX_ENCL_PAGE_LOADED) {
+ /*
+ * If the page has RECLAIMED set, the reclaimer effectively
+ * owns the page, i.e. we need to let the reclaimer free it.
+ */
+ if ((entry->desc & SGX_ENCL_PAGE_LOADED) &&
+ !(entry->desc & SGX_ENCL_PAGE_RECLAIMED)) {
if (!__sgx_free_page(entry->epc_page)) {
encl->secs_child_cnt--;
entry->desc &= ~SGX_ENCL_PAGE_LOADED;
@@ -101,6 +119,7 @@ void sgx_invalidate(struct sgx_encl *encl, bool flush_cpus)
encl->secs.desc &= ~SGX_ENCL_PAGE_LOADED;
sgx_free_page(encl->secs.epc_page);
}
+ sgx_free_va_pages(encl);
}
static bool sgx_process_add_page_req(struct sgx_add_page_req *req,
@@ -303,6 +322,51 @@ static const struct mmu_notifier_ops sgx_mmu_notifier_ops = {
.release = sgx_mmu_notifier_release,
};
+static int sgx_encl_grow(struct sgx_encl *encl)
+{
+ struct sgx_va_page *va_page;
+ int ret;
+
+ BUILD_BUG_ON(SGX_VA_SLOT_COUNT !=
+ (SGX_ENCL_PAGE_VA_OFFSET_MASK >> 3) + 1);
+
+ mutex_lock(&encl->lock);
+ if (encl->flags & SGX_ENCL_DEAD) {
+ mutex_unlock(&encl->lock);
+ return -EFAULT;
+ }
+
+ if (!(encl->page_cnt % SGX_VA_SLOT_COUNT)) {
+ mutex_unlock(&encl->lock);
+
+ va_page = kzalloc(sizeof(*va_page), GFP_KERNEL);
+ if (!va_page)
+ return -ENOMEM;
+ va_page->epc_page = sgx_alloc_va_page();
+ if (IS_ERR(va_page->epc_page)) {
+ ret = PTR_ERR(va_page->epc_page);
+ kfree(va_page);
+ return ret;
+ }
+
+ mutex_lock(&encl->lock);
+ if (encl->flags & SGX_ENCL_DEAD) {
+ sgx_free_page(va_page->epc_page);
+ kfree(va_page);
+ mutex_unlock(&encl->lock);
+ return -EFAULT;
+ } else if (encl->page_cnt % SGX_VA_SLOT_COUNT) {
+ sgx_free_page(va_page->epc_page);
+ kfree(va_page);
+ } else {
+ list_add(&va_page->list, &encl->va_pages);
+ }
+ }
+ encl->page_cnt++;
+ mutex_unlock(&encl->lock);
+ return 0;
+}
+
/**
* sgx_encl_alloc - allocate memory for an enclave and set attributes
*
@@ -321,6 +385,7 @@ struct sgx_encl *sgx_encl_alloc(struct sgx_secs *secs)
unsigned long ssaframesize;
struct sgx_encl *encl;
struct file *backing;
+ struct file *pcmd;
ssaframesize = sgx_calc_ssaframesize(secs->miscselect, secs->xfrm);
if (sgx_validate_secs(secs, ssaframesize))
@@ -331,9 +396,17 @@ struct sgx_encl *sgx_encl_alloc(struct sgx_secs *secs)
if (IS_ERR(backing))
return ERR_CAST(backing);
+ pcmd = shmem_file_setup("[dev/sgx]", (secs->size + PAGE_SIZE) >> 5,
+ VM_NORESERVE);
+ if (IS_ERR(pcmd)) {
+ fput(backing);
+ return ERR_CAST(pcmd);
+ }
+
encl = kzalloc(sizeof(*encl), GFP_KERNEL);
if (!encl) {
fput(backing);
+ fput(pcmd);
return ERR_PTR(-ENOMEM);
}
@@ -342,6 +415,7 @@ struct sgx_encl *sgx_encl_alloc(struct sgx_secs *secs)
kref_init(&encl->refcount);
INIT_LIST_HEAD(&encl->add_page_reqs);
+ INIT_LIST_HEAD(&encl->va_pages);
INIT_RADIX_TREE(&encl->page_tree, GFP_KERNEL);
mutex_init(&encl->lock);
INIT_WORK(&encl->add_page_work, sgx_add_page_worker);
@@ -351,6 +425,7 @@ struct sgx_encl *sgx_encl_alloc(struct sgx_secs *secs)
encl->size = secs->size;
encl->ssaframesize = secs->ssa_frame_size;
encl->backing = backing;
+ encl->pcmd = pcmd;
return encl;
}
@@ -402,6 +477,10 @@ int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs)
encl->secs.encl = encl;
encl->tgid = get_pid(task_tgid(current));
+ ret = sgx_encl_grow(encl);
+ if (ret)
+ return ret;
+
pginfo.addr = 0;
pginfo.contents = (unsigned long)secs;
pginfo.metadata = (unsigned long)&secinfo;
@@ -632,6 +711,9 @@ int sgx_encl_add_page(struct sgx_encl *encl, unsigned long addr, void *data,
if (ret)
return ret;
}
+ ret = sgx_encl_grow(encl);
+ if (ret)
+ return ret;
mutex_lock(&encl->lock);
if (encl->flags & (SGX_ENCL_INITIALIZED | SGX_ENCL_DEAD)) {
mutex_unlock(&encl->lock);
@@ -746,6 +828,111 @@ int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct,
return ret;
}
+/**
+ * sgx_encl_block - block an enclave page
+ * @encl_page: an enclave page
+ *
+ * Changes the state of the associated EPC page to blocked.
+ */
+void sgx_encl_block(struct sgx_encl_page *encl_page)
+{
+ unsigned long addr = SGX_ENCL_PAGE_ADDR(encl_page);
+ struct sgx_encl *encl = encl_page->encl;
+ struct vm_area_struct *vma;
+ int ret;
+
+ if (encl->flags & SGX_ENCL_DEAD)
+ return;
+
+ ret = sgx_encl_find(encl->mm, addr, &vma);
+ if (!ret && encl == vma->vm_private_data)
+ zap_vma_ptes(vma, addr, PAGE_SIZE);
+
+ ret = __eblock(sgx_epc_addr(encl_page->epc_page));
+ SGX_INVD(ret, encl, "EBLOCK returned %d (0x%x)", ret, ret);
+}
+
+/**
+ * sgx_encl_track - start tracking pages in the blocked state
+ * @encl: an enclave
+ *
+ * Start blocking accesses for pages in the blocked state for threads that enter
+ * inside the enclave by executing the ETRACK leaf instruction. This starts a
+ * shootdown sequence for threads that entered before ETRACK.
+ *
+ * The caller must take care (with an IPI when necessary) to make sure that the
+ * previous shootdown sequence was completed before calling this function. If
+ * this is not the case, the callee prints a critical error to the klog and
+ * kills the enclave.
+ */
+void sgx_encl_track(struct sgx_encl *encl)
+{
+ int ret = __etrack(sgx_epc_addr(encl->secs.epc_page));
+
+ SGX_INVD(ret, encl, "ETRACK returned %d (0x%x)", ret, ret);
+}
+
+/**
+ * sgx_encl_load_page - load an enclave page
+ * @encl_page: an enclave page
+ * @epc_page: an EPC page
+ *
+ * Loads an enclave page from the regular memory to the EPC. The pages, which
+ * are not children of a SECS (eg SECS itself and VA pages) should set their
+ * address to zero.
+ *
+ * Return:
+ * 0 on success,
+ * -errno or SGX error code on failure
+ */
+int sgx_encl_load_page(struct sgx_encl_page *encl_page,
+ struct sgx_epc_page *epc_page)
+{
+ unsigned long addr = SGX_ENCL_PAGE_ADDR(encl_page);
+ struct sgx_encl *encl = encl_page->encl;
+ struct sgx_pageinfo pginfo;
+ unsigned long pcmd_offset;
+ unsigned long va_offset;
+ pgoff_t backing_index;
+ struct page *backing;
+ struct page *pcmd;
+ int ret;
+
+ backing_index = sgx_encl_page_backing_index(encl_page, encl);
+ pcmd_offset = sgx_encl_page_pcmd_offset(encl_page, encl);
+ va_offset = SGX_ENCL_PAGE_VA_OFFSET(encl_page);
+
+ backing = sgx_get_backing(encl->backing, backing_index);
+ if (IS_ERR(backing))
+ return PTR_ERR(backing);
+
+ pcmd = sgx_get_backing(encl->pcmd, backing_index >> 5);
+ if (IS_ERR(pcmd)) {
+ sgx_put_backing(backing, false);
+ return PTR_ERR(pcmd);
+ }
+
+ pginfo.addr = addr;
+ pginfo.contents = (unsigned long)kmap_atomic(backing);
+ pginfo.metadata = (unsigned long)kmap_atomic(pcmd) + pcmd_offset;
+ pginfo.secs = addr ? (unsigned long)sgx_epc_addr(encl->secs.epc_page) :
+ 0;
+
+ ret = __eldu(&pginfo, sgx_epc_addr(epc_page),
+ sgx_epc_addr(encl_page->va_page->epc_page) + va_offset);
+ if (ret) {
+ SGX_INVD(ret, encl, "ELDU returned %d (0x%x)", ret, ret);
+ ret = encls_to_err(ret);
+ }
+
+ kunmap_atomic((void *)(unsigned long)(pginfo.metadata - pcmd_offset));
+ kunmap_atomic((void *)(unsigned long)pginfo.contents);
+
+ sgx_put_backing(pcmd, false);
+ sgx_put_backing(backing, false);
+ return ret;
+}
+
/**
* sgx_encl_release - destroy an enclave instance
* @kref: address of a kref inside &sgx_encl
@@ -774,11 +961,16 @@ void sgx_encl_release(struct kref *ref)
if (encl->tgid)
put_pid(encl->tgid);
+ sgx_free_va_pages(encl);
+
if (encl->secs.desc & SGX_ENCL_PAGE_LOADED)
sgx_free_page(encl->secs.epc_page);
if (encl->backing)
fput(encl->backing);
+ if (encl->pcmd)
+ fput(encl->pcmd);
+
kfree(encl);
}
diff --git a/drivers/platform/x86/intel_sgx/sgx_encl_page.c b/drivers/platform/x86/intel_sgx/sgx_encl_page.c
new file mode 100644
index 000000000000..fc9bea9f4aea
--- /dev/null
+++ b/drivers/platform/x86/intel_sgx/sgx_encl_page.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2016-18 Intel Corporation.
+
+#include <linux/device.h>
+#include <linux/freezer.h>
+#include <linux/highmem.h>
+#include <linux/kthread.h>
+#include <linux/ratelimit.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include "sgx.h"
+
+static inline struct sgx_encl_page *to_encl_page(struct sgx_epc_page *epc_page)
+{
+ WARN_ON_ONCE(1);
+ return NULL;
+}
+
+bool sgx_encl_page_get(struct sgx_epc_page *epc_page)
+{
+ struct sgx_encl_page *encl_page = to_encl_page(epc_page);
+ struct sgx_encl *encl = encl_page->encl;
+
+ return kref_get_unless_zero(&encl->refcount) != 0;
+}
+
+void sgx_encl_page_put(struct sgx_epc_page *epc_page)
+{
+ struct sgx_encl_page *encl_page = to_encl_page(epc_page);
+ struct sgx_encl *encl = encl_page->encl;
+
+ kref_put(&encl->refcount, sgx_encl_release);
+}
+
+bool sgx_encl_page_reclaim(struct sgx_epc_page *epc_page)
+{
+ struct sgx_encl_page *encl_page = to_encl_page(epc_page);
+ struct sgx_encl *encl = encl_page->encl;
+ bool ret;
+
+ down_read(&encl->mm->mmap_sem);
+ mutex_lock(&encl->lock);
+
+ if (encl->flags & SGX_ENCL_DEAD)
+ ret = true;
+ else if (encl_page->desc & SGX_ENCL_PAGE_RESERVED)
+ ret = false;
+ else
+ ret = !sgx_test_and_clear_young(encl_page);
+ if (ret)
+ encl_page->desc |= SGX_ENCL_PAGE_RECLAIMED;
+
+ mutex_unlock(&encl->lock);
+ up_read(&encl->mm->mmap_sem);
+
+ return ret;
+}
+
+void sgx_encl_page_block(struct sgx_epc_page *epc_page)
+{
+ struct sgx_encl_page *encl_page = to_encl_page(epc_page);
+ struct sgx_encl *encl = encl_page->encl;
+
+ down_read(&encl->mm->mmap_sem);
+ mutex_lock(&encl->lock);
+ sgx_encl_block(encl_page);
+ mutex_unlock(&encl->lock);
+ up_read(&encl->mm->mmap_sem);
+}
+
+static int sgx_ewb(struct sgx_encl *encl, struct sgx_epc_page *epc_page,
+ struct sgx_va_page *va_page, unsigned int va_offset)
+{
+ struct sgx_encl_page *encl_page = to_encl_page(epc_page);
+ int pcmd_offset = sgx_encl_page_pcmd_offset(encl_page, encl);
+ struct sgx_pageinfo pginfo;
+ pgoff_t backing_index;
+ struct page *backing;
+ struct page *pcmd;
+ int ret;
+
+ backing_index = sgx_encl_page_backing_index(encl_page, encl);
+
+ backing = sgx_get_backing(encl->backing, backing_index);
+ if (IS_ERR(backing)) {
+ ret = PTR_ERR(backing);
+ return ret;
+ }
+
+ pcmd = sgx_get_backing(encl->pcmd, backing_index >> 5);
+ if (IS_ERR(pcmd)) {
+ ret = PTR_ERR(pcmd);
+ sgx_put_backing(backing, true);
+ return ret;
+ }
+
+ pginfo.addr = 0;
+ pginfo.contents = (unsigned long)kmap_atomic(backing);
+ pginfo.metadata = (unsigned long)kmap_atomic(pcmd) + pcmd_offset;
+ pginfo.secs = 0;
+ ret = __ewb(&pginfo, sgx_epc_addr(epc_page),
+ sgx_epc_addr(va_page->epc_page) + va_offset);
+ kunmap_atomic((void *)(unsigned long)(pginfo.metadata - pcmd_offset));
+ kunmap_atomic((void *)(unsigned long)pginfo.contents);
+
+ sgx_put_backing(pcmd, true);
+ sgx_put_backing(backing, true);
+
+ return ret;
+}
+
+/**
+ * sgx_write_page - write a page to the regular memory
+ *
+ * Writes an EPC page to the shmem file associated with the enclave. Flushes
+ * CPUs and retries if there are hardware threads that can potentially have TLB
+ * entries to the page (indicated by SGX_NOT_TRACKED). Clears the reserved flag
+ * after the page is swapped.
+ *
+ * @epc_page: an EPC page
+ */
+static void sgx_write_page(struct sgx_epc_page *epc_page, bool do_free)
+{
+ struct sgx_encl_page *encl_page = to_encl_page(epc_page);
+ struct sgx_encl *encl = encl_page->encl;
+ struct sgx_va_page *va_page;
+ unsigned int va_offset;
+ int ret;
+
+ encl_page->desc &= ~(SGX_ENCL_PAGE_LOADED | SGX_ENCL_PAGE_RECLAIMED);
+
+ if (!(encl->flags & SGX_ENCL_DEAD)) {
+ va_page = list_first_entry(&encl->va_pages, struct sgx_va_page,
+ list);
+ va_offset = sgx_alloc_va_slot(va_page);
+ if (sgx_va_page_full(va_page))
+ list_move_tail(&va_page->list, &encl->va_pages);
+
+ ret = sgx_ewb(encl, epc_page, va_page, va_offset);
+ if (ret == SGX_NOT_TRACKED) {
+ sgx_encl_track(encl);
+ ret = sgx_ewb(encl, epc_page, va_page, va_offset);
+ if (ret == SGX_NOT_TRACKED) {
+ /* slow path, IPI needed */
+ sgx_flush_cpus(encl);
+ ret = sgx_ewb(encl, epc_page, va_page,
+ va_offset);
+ }
+ }
+ SGX_INVD(ret, encl, "EWB returned %d (0x%x)", ret, ret);
+
+ SGX_INVD(encl_page->desc & SGX_ENCL_PAGE_VA_OFFSET_MASK, encl,
+ "Flags set in VA offset area: %lx", encl_page->desc);
+ encl_page->desc |= va_offset;
+ encl_page->va_page = va_page;
+ } else if (!do_free) {
+ ret = __eremove(sgx_epc_addr(epc_page));
+ WARN(ret, "EREMOVE returned %d\n", ret);
+ }
+
+ if (do_free)
+ sgx_free_page(epc_page);
+}
+
+void sgx_encl_page_write(struct sgx_epc_page *epc_page)
+{
+ struct sgx_encl_page *encl_page = to_encl_page(epc_page);
+ struct sgx_encl *encl = encl_page->encl;
+
+ down_read(&encl->mm->mmap_sem);
+ mutex_lock(&encl->lock);
+ sgx_write_page(epc_page, false);
+ encl->secs_child_cnt--;
+ if (!encl->secs_child_cnt &&
+ (encl->flags & (SGX_ENCL_INITIALIZED | SGX_ENCL_DEAD)))
+ sgx_write_page(encl->secs.epc_page, true);
+ mutex_unlock(&encl->lock);
+ up_read(&encl->mm->mmap_sem);
+}
diff --git a/drivers/platform/x86/intel_sgx/sgx_fault.c b/drivers/platform/x86/intel_sgx/sgx_fault.c
new file mode 100644
index 000000000000..61d77e9f8fec
--- /dev/null
+++ b/drivers/platform/x86/intel_sgx/sgx_fault.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2016-18 Intel Corporation.
+
+#include <linux/highmem.h>
+#include <linux/sched/mm.h>
+#include "sgx.h"
+
+static struct sgx_epc_page *__sgx_load_faulted_page(
+ struct sgx_encl_page *encl_page)
+{
+ unsigned long va_offset = SGX_ENCL_PAGE_VA_OFFSET(encl_page);
+ struct sgx_encl *encl = encl_page->encl;
+ struct sgx_epc_page *epc_page;
+ int ret;
+
+ epc_page = sgx_alloc_page();
+ if (IS_ERR(epc_page))
+ return epc_page;
+ ret = sgx_encl_load_page(encl_page, epc_page);
+ if (ret) {
+ sgx_free_page(epc_page);
+ return ERR_PTR(ret);
+ }
+ sgx_free_va_slot(encl_page->va_page, va_offset);
+ list_move(&encl_page->va_page->list, &encl->va_pages);
+ encl_page->desc &= ~SGX_ENCL_PAGE_VA_OFFSET_MASK;
+ sgx_set_page_loaded(encl_page, epc_page);
+ return epc_page;
+}
+
+static struct sgx_encl_page *__sgx_fault_page(struct vm_area_struct *vma,
+ unsigned long addr,
+ bool do_reserve)
+{
+ struct sgx_encl *encl = vma->vm_private_data;
+ struct sgx_epc_page *epc_page;
+ struct sgx_encl_page *entry;
+ int rc = 0;
+
+ if ((encl->flags & SGX_ENCL_DEAD) ||
+ !(encl->flags & SGX_ENCL_INITIALIZED))
+ return ERR_PTR(-EFAULT);
+
+ entry = radix_tree_lookup(&encl->page_tree, addr >> PAGE_SHIFT);
+ if (!entry)
+ return ERR_PTR(-EFAULT);
+
+ /* Page is already resident in the EPC. */
+ if (entry->desc & SGX_ENCL_PAGE_LOADED) {
+ if (entry->desc & SGX_ENCL_PAGE_RESERVED) {
+ sgx_dbg(encl, "EPC page 0x%p is already reserved\n",
+ (void *)SGX_ENCL_PAGE_ADDR(entry));
+ return ERR_PTR(-EBUSY);
+ }
+ if (entry->desc & SGX_ENCL_PAGE_RECLAIMED) {
+ sgx_dbg(encl, "EPC page 0x%p is being reclaimed\n",
+ (void *)SGX_ENCL_PAGE_ADDR(entry));
+ return ERR_PTR(-EBUSY);
+ }
+ if (do_reserve)
+ entry->desc |= SGX_ENCL_PAGE_RESERVED;
+ return entry;
+ }
+
+ if (!(encl->secs.desc & SGX_ENCL_PAGE_LOADED)) {
+ epc_page = __sgx_load_faulted_page(&encl->secs);
+ if (IS_ERR(epc_page))
+ return ERR_CAST(epc_page);
+ }
+ epc_page = __sgx_load_faulted_page(entry);
+ if (IS_ERR(epc_page))
+ return ERR_CAST(epc_page);
+
+ encl->secs_child_cnt++;
+ sgx_test_and_clear_young(entry);
+ if (do_reserve)
+ entry->desc |= SGX_ENCL_PAGE_RESERVED;
+
+ rc = vmf_insert_pfn(vma, addr, PFN_DOWN(entry->epc_page->desc));
+ if (rc != VM_FAULT_NOPAGE) {
+ sgx_invalidate(encl, true);
+ return ERR_PTR(-EFAULT);
+ }
+
+ return entry;
+}
+
+struct sgx_encl_page *sgx_fault_page(struct vm_area_struct *vma,
+ unsigned long addr, bool do_reserve)
+{
+ struct sgx_encl *encl = vma->vm_private_data;
+ struct sgx_encl_page *entry;
+
+ /* If process was forked, VMA is still there but vm_private_data is set
+ * to NULL.
+ */
+ if (!encl)
+ return ERR_PTR(-EFAULT);
+ do {
+ mutex_lock(&encl->lock);
+ entry = __sgx_fault_page(vma, addr, do_reserve);
+ mutex_unlock(&encl->lock);
+ if (!do_reserve)
+ break;
+ } while (PTR_ERR(entry) == -EBUSY);
+
+ return entry;
+}
diff --git a/drivers/platform/x86/intel_sgx/sgx_util.c b/drivers/platform/x86/intel_sgx/sgx_util.c
index cbea4c0e794b..eb8072b36a47 100644
--- a/drivers/platform/x86/intel_sgx/sgx_util.c
+++ b/drivers/platform/x86/intel_sgx/sgx_util.c
@@ -67,6 +67,77 @@ void sgx_set_page_loaded(struct sgx_encl_page *encl_page,
encl_page->epc_page = epc_page;
}
+/**
+ * sgx_alloc_page - allocate a VA page
+ *
+ * Allocates an &sgx_epc_page instance and converts it to a VA page.
+ *
+ * Return:
+ * a &struct sgx_va_page instance,
+ * -errno otherwise
+ */
+struct sgx_epc_page *sgx_alloc_va_page(void)
+{
+ struct sgx_epc_page *epc_page;
+ int ret;
+
+ epc_page = sgx_alloc_page();
+ if (IS_ERR(epc_page))
+ return ERR_CAST(epc_page);
+
+ ret = __epa(sgx_epc_addr(epc_page));
+ if (ret) {
+ WARN_ONCE(1, "sgx: EPA returned %d (0x%x)", ret, ret);
+ sgx_free_page(epc_page);
+ return ERR_PTR(encls_to_err(ret));
+ }
+
+ return epc_page;
+}
+
+/**
+ * sgx_alloc_va_slot - allocate a VA slot
+ * @va_page: a &struct sgx_va_page instance
+ *
+ * Allocates a slot from a &struct sgx_va_page instance.
+ *
+ * Return: offset of the slot inside the VA page
+ */
+unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page)
+{
+ int slot = find_first_zero_bit(va_page->slots, SGX_VA_SLOT_COUNT);
+
+ if (slot < SGX_VA_SLOT_COUNT)
+ set_bit(slot, va_page->slots);
+
+ return slot << 3;
+}
+
+/**
+ * sgx_free_va_slot - free a VA slot
+ * @va_page: a &struct sgx_va_page instance
+ * @offset: offset of the slot inside the VA page
+ *
+ * Frees a slot from a &struct sgx_va_page instance.
+ */
+void sgx_free_va_slot(struct sgx_va_page *va_page, unsigned int offset)
+{
+ clear_bit(offset >> 3, va_page->slots);
+}
+
+/**
+ * sgx_va_page_full - is the VA page full?
+ * @va_page: a &struct sgx_va_page instance
+ *
+ * Return: true if all slots have been taken
+ */
+bool sgx_va_page_full(struct sgx_va_page *va_page)
+{
+ int slot = find_first_zero_bit(va_page->slots, SGX_VA_SLOT_COUNT);
+
+ return slot == SGX_VA_SLOT_COUNT;
+}
+
struct page *sgx_get_backing(struct file *file, pgoff_t index)
{
struct inode *inode = file->f_path.dentry->d_inode;
diff --git a/drivers/platform/x86/intel_sgx/sgx_vma.c b/drivers/platform/x86/intel_sgx/sgx_vma.c
index 17e95a0c734c..cc0993b4fd40 100644
--- a/drivers/platform/x86/intel_sgx/sgx_vma.c
+++ b/drivers/platform/x86/intel_sgx/sgx_vma.c
@@ -37,7 +37,22 @@ static void sgx_vma_close(struct vm_area_struct *vma)
kref_put(&encl->refcount, sgx_encl_release);
}
+static int sgx_vma_fault(struct vm_fault *vmf)
+{
+ unsigned long addr = (unsigned long)vmf->address;
+ struct vm_area_struct *vma = vmf->vma;
+ struct sgx_encl_page *entry;
+
+ entry = sgx_fault_page(vma, addr, 0);
+
+ if (!IS_ERR(entry) || PTR_ERR(entry) == -EBUSY)
+ return VM_FAULT_NOPAGE;
+ else
+ return VM_FAULT_SIGBUS;
+}
+
const struct vm_operations_struct sgx_vm_ops = {
.close = sgx_vma_close,
.open = sgx_vma_open,
+ .fault = sgx_vma_fault,
};
--
2.19.1
From: Sean Christopherson <[email protected]>
Enumerate Enclave Page Cache (EPC) sections via CPUID and add the data
structures necessary to track EPC pages so that they can be allocated,
freed and managed. As a system may have multiple EPC sections, invoke
CPUID on SGX sub-leafs until an invalid leaf is encountered.
On NUMA systems, a node can have at most one bank. A bank can be at
most part of two nodes. SGX supports both nodes with a single memory
controller and also sub-cluster nodes with severals memory controllers
on a single die.
For simplicity, support a maximum of eight EPC sections. Current
client hardware supports only a single section, while upcoming server
hardware will support at most eight sections. Bounding the number of
sections also allows the section ID to be embedded along with a page's
offset in a single unsigned long, enabling easy retrieval of both the
VA and PA for a given page.
Co-developed-by: Jarkko Sakkinen <[email protected]>
Co-developed-by: Suresh Siddha <[email protected]>
Co-developed-by: Serge Ayoun <[email protected]>
Signed-off-by: Serge Ayoun <[email protected]>
Signed-off-by: Suresh Siddha <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
arch/x86/Kconfig | 17 ++++
arch/x86/include/asm/sgx.h | 57 +++++++++++++
arch/x86/kernel/cpu/Makefile | 1 +
arch/x86/kernel/cpu/intel_sgx.c | 137 ++++++++++++++++++++++++++++++++
4 files changed, 212 insertions(+)
create mode 100644 arch/x86/kernel/cpu/intel_sgx.c
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1a0be022f91d..b47e1a144409 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1913,6 +1913,23 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS
If unsure, say y.
+config INTEL_SGX_CORE
+ bool "Intel SGX core functionality"
+ depends on X86_64 && CPU_SUP_INTEL
+ help
+ Intel Software Guard eXtensions (SGX) CPU feature that allows ring 3
+ applications to create enclaves: private regions of memory that are
+ architecturally protected from unauthorized access and/or modification.
+
+ This option enables kernel recognition of SGX, high-level management
+ of the Enclave Page Cache (EPC), tracking and writing of SGX Launch
+ Enclave Hash MSRs, and allows for virtualization of SGX via KVM. By
+ itself, this option does not provide SGX support to userspace.
+
+ For details, see Documentation/x86/intel_sgx.rst
+
+ If unsure, say N.
+
config EFI
bool "EFI runtime service support"
depends on ACPI
diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index 23361d508348..aa51165eb3a8 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -5,9 +5,66 @@
#ifndef _ASM_X86_SGX_H
#define _ASM_X86_SGX_H
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/rwsem.h>
+#include <linux/types.h>
#include <asm/asm.h>
#include <asm/sgx_arch.h>
+struct sgx_epc_page {
+ unsigned long desc;
+ struct list_head list;
+};
+
+/**
+ * struct sgx_epc_section
+ *
+ * The firmware can define multiple chunks of EPC to the different areas of the
+ * physical memory e.g. for memory areas of the each node. This structure is
+ * used to store EPC pages for one EPC section and virtual memory area where
+ * the pages have been mapped.
+ */
+struct sgx_epc_section {
+ unsigned long pa;
+ void __iomem *va;
+ struct sgx_epc_page **pages;
+ unsigned long free_cnt;
+ spinlock_t lock;
+};
+
+#define SGX_MAX_EPC_SECTIONS 8
+
+extern struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS];
+
+/**
+ * enum sgx_epc_page_desc - bits and masks for an EPC page's descriptor
+ * %SGX_EPC_SECTION_MASK: SGX allows to have multiple EPC sections in the
+ * physical memory. The existing and near-future
+ * hardware defines at most eight sections, hence
+ * three bits to hold a section.
+ * %SGX_EPC_PAGE_RECLAIMABLE: The page page is reclaimable. Used when freeing
+ * a page to know that we also need to remove the
+ * page from the list of reclaimable pages.
+ */
+enum sgx_epc_page_desc {
+ SGX_EPC_SECTION_MASK = GENMASK_ULL(3, 0),
+ SGX_EPC_PAGE_RECLAIMABLE = BIT(4),
+ /* bits 12-63 are reserved for the physical page address of the page */
+};
+
+static inline struct sgx_epc_section *sgx_epc_section(struct sgx_epc_page *page)
+{
+ return &sgx_epc_sections[page->desc & SGX_EPC_SECTION_MASK];
+}
+
+static inline void __iomem *sgx_epc_addr(struct sgx_epc_page *page)
+{
+ struct sgx_epc_section *section = sgx_epc_section(page);
+
+ return section->va + (page->desc & PAGE_MASK) - section->pa;
+}
+
/**
* ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
*
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 347137e80bf5..71876f2b35fc 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_CPU_SUP_UMC_32) += umc.o
obj-$(CONFIG_INTEL_RDT) += intel_rdt.o intel_rdt_rdtgroup.o intel_rdt_monitor.o
obj-$(CONFIG_INTEL_RDT) += intel_rdt_ctrlmondata.o intel_rdt_pseudo_lock.o
CFLAGS_intel_rdt_pseudo_lock.o = -I$(src)
+obj-$(CONFIG_INTEL_SGX_CORE) += intel_sgx.o
obj-$(CONFIG_X86_MCE) += mcheck/
obj-$(CONFIG_MTRR) += mtrr/
diff --git a/arch/x86/kernel/cpu/intel_sgx.c b/arch/x86/kernel/cpu/intel_sgx.c
new file mode 100644
index 000000000000..b86aa4111592
--- /dev/null
+++ b/arch/x86/kernel/cpu/intel_sgx.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2016-17 Intel Corporation.
+
+#include <linux/freezer.h>
+#include <linux/highmem.h>
+#include <linux/kthread.h>
+#include <linux/pagemap.h>
+#include <linux/ratelimit.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <asm/sgx.h>
+
+struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS];
+EXPORT_SYMBOL_GPL(sgx_epc_sections);
+
+static int sgx_nr_epc_sections;
+
+static __init void sgx_free_epc_section(struct sgx_epc_section *section)
+{
+ int i;
+
+ for (i = 0; i < section->free_cnt && section->pages[i]; i++)
+ kfree(section->pages[i]);
+ kfree(section->pages);
+ iounmap(section->va);
+}
+
+static __init int sgx_init_epc_section(u64 addr, u64 size, unsigned long index,
+ struct sgx_epc_section *section)
+{
+ unsigned long nr_pages = size >> PAGE_SHIFT;
+ unsigned long i;
+
+ section->va = ioremap_cache(addr, size);
+ if (!section->va)
+ return -ENOMEM;
+
+ section->pa = addr;
+ section->free_cnt = nr_pages;
+ spin_lock_init(§ion->lock);
+
+ section->pages = kcalloc(nr_pages, sizeof(struct sgx_epc_page *),
+ GFP_KERNEL);
+ if (!section->pages)
+ goto out;
+
+ for (i = 0; i < nr_pages; i++) {
+ section->pages[i] = kzalloc(sizeof(struct sgx_epc_page),
+ GFP_KERNEL);
+ if (!section->pages[i])
+ goto out;
+
+ section->pages[i]->desc = (addr + (i << PAGE_SHIFT)) | index;
+ }
+
+ return 0;
+out:
+ sgx_free_epc_section(section);
+ return -ENOMEM;
+}
+
+static __init void sgx_page_cache_teardown(void)
+{
+ int i;
+
+ for (i = 0; i < sgx_nr_epc_sections; i++)
+ sgx_free_epc_section(&sgx_epc_sections[i]);
+}
+
+/**
+ * A section metric is concatenated in a way that @low bits 12-31 define the
+ * bits 12-31 of the metric and @high bits 0-19 define the bits 32-51 of the
+ * metric.
+ */
+static inline u64 sgx_calc_section_metric(u64 low, u64 high)
+{
+ return (low & GENMASK_ULL(31, 12)) +
+ ((high & GENMASK_ULL(19, 0)) << 32);
+}
+
+static __init int sgx_page_cache_init(void)
+{
+ u32 eax, ebx, ecx, edx, type;
+ u64 pa, size;
+ int ret;
+ int i;
+
+ BUILD_BUG_ON(SGX_MAX_EPC_SECTIONS > (SGX_EPC_SECTION_MASK + 1));
+
+ for (i = 0; i < SGX_MAX_EPC_SECTIONS; i++) {
+ cpuid_count(SGX_CPUID, i + SGX_CPUID_FIRST_VARIABLE_SUB_LEAF,
+ &eax, &ebx, &ecx, &edx);
+
+ type = eax & SGX_CPUID_SUB_LEAF_TYPE_MASK;
+ if (type == SGX_CPUID_SUB_LEAF_INVALID)
+ break;
+ if (type != SGX_CPUID_SUB_LEAF_EPC_SECTION) {
+ pr_err_once("sgx: Unknown sub-leaf type: %u\n", type);
+ continue;
+ }
+
+ pa = sgx_calc_section_metric(eax, ebx);
+ size = sgx_calc_section_metric(ecx, edx);
+ pr_info("sgx: EPC section 0x%llx-0x%llx\n", pa, pa + size - 1);
+
+ ret = sgx_init_epc_section(pa, size, i, &sgx_epc_sections[i]);
+ if (ret) {
+ sgx_page_cache_teardown();
+ return ret;
+ }
+
+ sgx_nr_epc_sections++;
+ }
+
+ if (!sgx_nr_epc_sections) {
+ pr_err("sgx: There are zero EPC sections.\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static __init int sgx_init(void)
+{
+ int ret;
+
+ if (!boot_cpu_has(X86_FEATURE_SGX))
+ return false;
+
+ ret = sgx_page_cache_init();
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+arch_initcall(sgx_init);
--
2.19.1
Intel Software Guard eXtensions (SGX) is a set of CPU instructions that
can be used by applications to set aside private regions of code and
data. The code outside the enclave is disallowed to access the memory
inside the enclave by the CPU access control.
SGX driver provides a ioctl API for loading and initializing enclaves.
Address range for enclaves is reserved with mmap() and they are
destroyed with munmap(). Enclave construction, measurement and
initialization is done with the provided the ioctl API.
Signed-off-by: Jarkko Sakkinen <[email protected]>
Co-developed-by: Sean Christopherson <[email protected]>
Co-developed-by: Serge Ayoun <[email protected]>
Co-developed-by: Shay Katz-zamir <[email protected]>
Co-developed-by: Suresh Siddha <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Serge Ayoun <[email protected]>
Signed-off-by: Shay Katz-zamir <[email protected]>
Signed-off-by: Suresh Siddha <[email protected]>
---
arch/x86/include/uapi/asm/sgx.h | 59 ++
drivers/platform/x86/Kconfig | 2 +
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/intel_sgx/Kconfig | 20 +
drivers/platform/x86/intel_sgx/Makefile | 12 +
drivers/platform/x86/intel_sgx/sgx.h | 180 +++++
drivers/platform/x86/intel_sgx/sgx_encl.c | 784 +++++++++++++++++++++
drivers/platform/x86/intel_sgx/sgx_ioctl.c | 234 ++++++
drivers/platform/x86/intel_sgx/sgx_main.c | 267 +++++++
drivers/platform/x86/intel_sgx/sgx_util.c | 85 +++
drivers/platform/x86/intel_sgx/sgx_vma.c | 43 ++
11 files changed, 1687 insertions(+)
create mode 100644 arch/x86/include/uapi/asm/sgx.h
create mode 100644 drivers/platform/x86/intel_sgx/Kconfig
create mode 100644 drivers/platform/x86/intel_sgx/Makefile
create mode 100644 drivers/platform/x86/intel_sgx/sgx.h
create mode 100644 drivers/platform/x86/intel_sgx/sgx_encl.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_ioctl.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_main.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_util.c
create mode 100644 drivers/platform/x86/intel_sgx/sgx_vma.c
diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h
new file mode 100644
index 000000000000..aadf9c76e360
--- /dev/null
+++ b/arch/x86/include/uapi/asm/sgx.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/**
+ * Copyright(c) 2016-18 Intel Corporation.
+ */
+#ifndef _UAPI_ASM_X86_SGX_H
+#define _UAPI_ASM_X86_SGX_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+#define SGX_MAGIC 0xA4
+
+#define SGX_IOC_ENCLAVE_CREATE \
+ _IOW(SGX_MAGIC, 0x00, struct sgx_enclave_create)
+#define SGX_IOC_ENCLAVE_ADD_PAGE \
+ _IOW(SGX_MAGIC, 0x01, struct sgx_enclave_add_page)
+#define SGX_IOC_ENCLAVE_INIT \
+ _IOW(SGX_MAGIC, 0x02, struct sgx_enclave_init)
+
+/* IOCTL return values */
+#define SGX_POWER_LOST_ENCLAVE 0x40000000
+
+/**
+ * struct sgx_enclave_create - parameter structure for the
+ * %SGX_IOC_ENCLAVE_CREATE ioctl
+ * @src: address for the SECS page data
+ */
+struct sgx_enclave_create {
+ __u64 src;
+};
+
+/**
+ * struct sgx_enclave_add_page - parameter structure for the
+ * %SGX_IOC_ENCLAVE_ADD_PAGE ioctl
+ * @addr: address within the ELRANGE
+ * @src: address for the page data
+ * @secinfo: address for the SECINFO data
+ * @mrmask: bitmask for the measured 256 byte chunks
+ */
+struct sgx_enclave_add_page {
+ __u64 addr;
+ __u64 src;
+ __u64 secinfo;
+ __u16 mrmask;
+} __attribute__((__packed__));
+
+
+/**
+ * struct sgx_enclave_init - parameter structure for the
+ * %SGX_IOC_ENCLAVE_INIT ioctl
+ * @addr: address within the ELRANGE
+ * @sigstruct: address for the SIGSTRUCT data
+ */
+struct sgx_enclave_init {
+ __u64 addr;
+ __u64 sigstruct;
+};
+
+#endif /* _UAPI_ASM_X86_SGX_H */
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 0c1aa6c314f5..66a1ab6235e2 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1229,6 +1229,8 @@ config I2C_MULTI_INSTANTIATE
To compile this driver as a module, choose M here: the module
will be called i2c-multi-instantiate.
+source "drivers/platform/x86/intel_sgx/Kconfig"
+
endif # X86_PLATFORM_DEVICES
config PMC_ATOM
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index e6d1becf81ce..d0db8c66ed3c 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -92,3 +92,4 @@ obj-$(CONFIG_MLX_PLATFORM) += mlx-platform.o
obj-$(CONFIG_INTEL_TURBO_MAX_3) += intel_turbo_max_3.o
obj-$(CONFIG_INTEL_CHTDC_TI_PWRBTN) += intel_chtdc_ti_pwrbtn.o
obj-$(CONFIG_I2C_MULTI_INSTANTIATE) += i2c-multi-instantiate.o
+obj-$(CONFIG_INTEL_SGX) += intel_sgx/
diff --git a/drivers/platform/x86/intel_sgx/Kconfig b/drivers/platform/x86/intel_sgx/Kconfig
new file mode 100644
index 000000000000..7d22d44acce9
--- /dev/null
+++ b/drivers/platform/x86/intel_sgx/Kconfig
@@ -0,0 +1,20 @@
+#
+# Intel SGX
+#
+
+config INTEL_SGX
+ tristate "Intel(R) SGX Driver"
+ depends on X86_64 && CPU_SUP_INTEL && INTEL_SGX_CORE
+ select MMU_NOTIFIER
+ select CRYPTO
+ select CRYPTO_SHA256
+ help
+ Intel(R) SGX is a set of CPU instructions that can be used by
+ applications to set aside private regions of code and data. The code
+ outside the enclave is disallowed to access the memory inside the
+ enclave by the CPU access control.
+
+ The firmware uses PRMRR registers to reserve an area of physical memory
+ called Enclave Page Cache (EPC). There is a hardware unit in the
+ processor called Memory Encryption Engine. The MEE encrypts and decrypts
+ the EPC pages as they enter and leave the processor package.
diff --git a/drivers/platform/x86/intel_sgx/Makefile b/drivers/platform/x86/intel_sgx/Makefile
new file mode 100644
index 000000000000..117e97effeff
--- /dev/null
+++ b/drivers/platform/x86/intel_sgx/Makefile
@@ -0,0 +1,12 @@
+#
+# Intel SGX
+#
+
+obj-$(CONFIG_INTEL_SGX) += intel_sgx.o
+
+intel_sgx-$(CONFIG_INTEL_SGX) += \
+ sgx_encl.o \
+ sgx_ioctl.o \
+ sgx_main.o \
+ sgx_util.o \
+ sgx_vma.o \
diff --git a/drivers/platform/x86/intel_sgx/sgx.h b/drivers/platform/x86/intel_sgx/sgx.h
new file mode 100644
index 000000000000..67bd8ea1d53d
--- /dev/null
+++ b/drivers/platform/x86/intel_sgx/sgx.h
@@ -0,0 +1,180 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/**
+ * Copyright(c) 2016-18 Intel Corporation.
+ */
+#ifndef __ARCH_INTEL_SGX_H__
+#define __ARCH_INTEL_SGX_H__
+
+#include <crypto/hash.h>
+#include <linux/kref.h>
+#include <linux/mmu_notifier.h>
+#include <linux/mmu_notifier.h>
+#include <linux/radix-tree.h>
+#include <linux/radix-tree.h>
+#include <linux/rbtree.h>
+#include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/workqueue.h>
+#include <asm/sgx.h>
+#include <uapi/asm/sgx.h>
+
+#define sgx_pr(level, encl, fmt, ...) \
+ pr_ ## level("sgx: [%d:0x%p] " fmt, pid_nr((encl)->tgid), \
+ (void *)(encl)->base, ##__VA_ARGS__)
+#define sgx_dbg(encl, fmt, ...) \
+ sgx_pr(debug, encl, fmt, ##__VA_ARGS__)
+#define sgx_info(encl, fmt, ...) \
+ sgx_pr(info, encl, fmt, ##__VA_ARGS__)
+#define sgx_warn(encl, fmt, ...) \
+ sgx_pr(warn, encl, fmt, ##__VA_ARGS__)
+#define sgx_err(encl, fmt, ...) \
+ sgx_pr(err, encl, fmt, ##__VA_ARGS__)
+#define sgx_crit(encl, fmt, ...) \
+ sgx_pr(crit, encl, fmt, ##__VA_ARGS__)
+
+#define SGX_EINIT_SPIN_COUNT 20
+#define SGX_EINIT_SLEEP_COUNT 50
+#define SGX_EINIT_SLEEP_TIME 20
+
+/**
+ * enum sgx_encl_page_desc - defines bits for an enclave page's descriptor
+ * %SGX_ENCL_PAGE_TCS: The page is a TCS page.
+ * %SGX_ENCL_PAGE_LOADED: The page is not swapped.
+ * %SGX_ENCL_PAGE_ADDR_MASK: Holds the virtual address of the page.
+ */
+enum sgx_encl_page_desc {
+ SGX_ENCL_PAGE_TCS = BIT(0),
+ SGX_ENCL_PAGE_LOADED = BIT(1),
+ /* Bits 11:3 are available when the page is not swapped. */
+ SGX_ENCL_PAGE_ADDR_MASK = PAGE_MASK,
+};
+
+#define SGX_ENCL_PAGE_ADDR(encl_page) \
+ ((encl_page)->desc & SGX_ENCL_PAGE_ADDR_MASK)
+#define SGX_ENCL_PAGE_VA_OFFSET(encl_page) \
+ ((encl_page)->desc & SGX_ENCL_PAGE_VA_OFFSET_MASK)
+
+struct sgx_encl_page {
+ unsigned long desc;
+ union {
+ struct sgx_epc_page *epc_page;
+ struct sgx_va_page *va_page;
+ };
+ struct sgx_encl *encl;
+};
+
+enum sgx_encl_flags {
+ SGX_ENCL_INITIALIZED = BIT(0),
+ SGX_ENCL_DEBUG = BIT(1),
+ SGX_ENCL_SUSPEND = BIT(2),
+ SGX_ENCL_DEAD = BIT(3),
+};
+
+struct sgx_encl {
+ unsigned int flags;
+ uint64_t attributes;
+ uint64_t xfrm;
+ unsigned int page_cnt;
+ unsigned int secs_child_cnt;
+ struct mutex lock;
+ struct mm_struct *mm;
+ struct file *backing;
+ struct kref refcount;
+ unsigned long base;
+ unsigned long size;
+ unsigned long ssaframesize;
+ struct radix_tree_root page_tree;
+ struct list_head add_page_reqs;
+ struct work_struct add_page_work;
+ struct sgx_encl_page secs;
+ struct pid *tgid;
+ struct mmu_notifier mmu_notifier;
+ struct notifier_block pm_notifier;
+};
+
+static inline pgoff_t sgx_encl_page_backing_index(struct sgx_encl_page *page,
+ struct sgx_encl *encl)
+{
+ /* The backing page for SECS is located after the enclave pages. */
+ if (!PFN_DOWN(page->desc))
+ return PFN_DOWN(encl->size);
+
+ return PFN_DOWN(page->desc - encl->base);
+}
+
+extern struct workqueue_struct *sgx_add_page_wq;
+extern u64 sgx_encl_size_max_32;
+extern u64 sgx_encl_size_max_64;
+extern u64 sgx_xfrm_mask;
+extern u32 sgx_misc_reserved;
+extern u32 sgx_xsave_size_tbl[64];
+extern int sgx_epcm_trapnr;
+
+extern const struct vm_operations_struct sgx_vm_ops;
+
+int sgx_encl_find(struct mm_struct *mm, unsigned long addr,
+ struct vm_area_struct **vma);
+void sgx_invalidate(struct sgx_encl *encl, bool flush_cpus);
+
+/**
+ * SGX_INVD - invalidate an enclave on failure, i.e. if ret != 0
+ *
+ * @ret: a return code to check
+ * @encl: pointer to an enclave
+ * @fmt: message for WARN if failure is detected
+ * @...: optional arguments used by @fmt
+ *
+ * SGX_INVD is used in flows where an error, i.e. @ret is non-zero, is
+ * indicative of a driver bug. Invalidate @encl if @ret indicates an
+ * error and WARN on error unless the error was due to a fault signaled
+ * by the EPCM.
+ *
+ * Faults from the EPCM occur in normal kernel operation, e.g. due to
+ * misonfigured mprotect() from userspace or because the EPCM invalidated
+ * all EPC pages. The EPCM invalidates the EPC on transitions to S3 or
+ * lower sleep states, and VMMs emulate loss of EPC when migrating VMs.
+ *
+ * Defined as a macro instead of a function so that WARN can provide a
+ * more precise trace.
+ */
+#define SGX_INVD(ret, encl, fmt, ...) \
+do { \
+ if (unlikely(ret)) { \
+ int trapnr = IS_ENCLS_FAULT(ret) ? ENCLS_TRAPNR(ret) : 0; \
+ WARN(trapnr != sgx_epcm_trapnr, fmt, ##__VA_ARGS__); \
+ sgx_invalidate(encl, true); \
+ } \
+} while (0)
+
+struct sgx_encl *sgx_encl_alloc(struct sgx_secs *secs);
+int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs);
+struct sgx_encl_page *sgx_encl_alloc_page(struct sgx_encl *encl,
+ unsigned long addr);
+void sgx_encl_free_page(struct sgx_encl_page *encl_page);
+int sgx_encl_add_page(struct sgx_encl *encl, unsigned long addr, void *data,
+ struct sgx_secinfo *secinfo, unsigned int mrmask);
+int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct,
+ struct sgx_einittoken *einittoken);
+void sgx_encl_block(struct sgx_encl_page *encl_page);
+void sgx_encl_track(struct sgx_encl *encl);
+int sgx_encl_load_page(struct sgx_encl_page *encl_page,
+ struct sgx_epc_page *epc_page);
+void sgx_encl_release(struct kref *ref);
+
+long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg);
+#ifdef CONFIG_COMPAT
+long sgx_compat_ioctl(struct file *filep, unsigned int cmd, unsigned long arg);
+#endif
+
+struct sgx_encl_page *sgx_fault_page(struct vm_area_struct *vma,
+ unsigned long addr,
+ bool do_reserve);
+
+int sgx_test_and_clear_young(struct sgx_encl_page *page);
+void sgx_flush_cpus(struct sgx_encl *encl);
+void sgx_set_page_loaded(struct sgx_encl_page *encl_page,
+ struct sgx_epc_page *epc_page);
+struct page *sgx_get_backing(struct file *file, pgoff_t index);
+void sgx_put_backing(struct page *backing_page, bool write);
+
+#endif /* __ARCH_X86_INTEL_SGX_H__ */
diff --git a/drivers/platform/x86/intel_sgx/sgx_encl.c b/drivers/platform/x86/intel_sgx/sgx_encl.c
new file mode 100644
index 000000000000..6bed944c2f92
--- /dev/null
+++ b/drivers/platform/x86/intel_sgx/sgx_encl.c
@@ -0,0 +1,784 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2016-18 Intel Corporation.
+
+#include <asm/mman.h>
+#include <linux/delay.h>
+#include <linux/file.h>
+#include <linux/hashtable.h>
+#include <linux/highmem.h>
+#include <linux/ratelimit.h>
+#include <linux/sched/signal.h>
+#include <linux/shmem_fs.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+#include "sgx.h"
+
+struct sgx_add_page_req {
+ struct sgx_encl *encl;
+ struct sgx_encl_page *encl_page;
+ struct sgx_secinfo secinfo;
+ unsigned long mrmask;
+ struct list_head list;
+};
+
+/**
+ * sgx_encl_find - find an enclave
+ * @mm: mm struct of the current process
+ * @addr: address in the ELRANGE
+ * @vma: the resulting VMA
+ *
+ * Finds an enclave identified by the given address. Gives back the VMA, that
+ * is part of the enclave, located in that address. The VMA is given back if it
+ * is a proper enclave VMA even if an &sgx_encl instance does not exist
+ * yet (enclave creation has not been performed).
+ *
+ * Return:
+ * 0 on success,
+ * -EINVAL if an enclave was not found,
+ * -ENOENT if the enclave has not been created yet
+ */
+int sgx_encl_find(struct mm_struct *mm, unsigned long addr,
+ struct vm_area_struct **vma)
+{
+ struct vm_area_struct *result;
+ struct sgx_encl *encl;
+
+ result = find_vma(mm, addr);
+ if (!result || result->vm_ops != &sgx_vm_ops || addr < result->vm_start)
+ return -EINVAL;
+
+ encl = result->vm_private_data;
+ *vma = result;
+
+ return encl ? 0 : -ENOENT;
+}
+
+/**
+ * sgx_invalidate - kill an enclave
+ * @encl: an &sgx_encl instance
+ * @flush_cpus Set if there can be active threads inside the enclave.
+ *
+ * Mark the enclave as dead and immediately free its EPC pages (but not
+ * its resources). For active enclaves, the entry points to the enclave
+ * are destroyed first and hardware threads are kicked out so that the
+ * EPC pages can be safely manipulated.
+ */
+void sgx_invalidate(struct sgx_encl *encl, bool flush_cpus)
+{
+ struct sgx_encl_page *entry;
+ struct radix_tree_iter iter;
+ struct vm_area_struct *vma;
+ unsigned long addr;
+ void **slot;
+
+ if (encl->flags & SGX_ENCL_DEAD)
+ return;
+
+ encl->flags |= SGX_ENCL_DEAD;
+ if (flush_cpus && (encl->flags & SGX_ENCL_INITIALIZED)) {
+ radix_tree_for_each_slot(slot, &encl->page_tree, &iter, 0) {
+ entry = *slot;
+ addr = SGX_ENCL_PAGE_ADDR(entry);
+ if ((entry->desc & SGX_ENCL_PAGE_LOADED) &&
+ (entry->desc & SGX_ENCL_PAGE_TCS) &&
+ !sgx_encl_find(encl->mm, addr, &vma))
+ zap_vma_ptes(vma, addr, PAGE_SIZE);
+ }
+ sgx_flush_cpus(encl);
+ }
+ radix_tree_for_each_slot(slot, &encl->page_tree, &iter, 0) {
+ entry = *slot;
+ if (entry->desc & SGX_ENCL_PAGE_LOADED) {
+ if (!__sgx_free_page(entry->epc_page)) {
+ encl->secs_child_cnt--;
+ entry->desc &= ~SGX_ENCL_PAGE_LOADED;
+ }
+ }
+ }
+
+ if (!encl->secs_child_cnt &&
+ (encl->secs.desc & SGX_ENCL_PAGE_LOADED)) {
+ encl->secs.desc &= ~SGX_ENCL_PAGE_LOADED;
+ sgx_free_page(encl->secs.epc_page);
+ }
+}
+
+static bool sgx_process_add_page_req(struct sgx_add_page_req *req,
+ struct sgx_epc_page *epc_page)
+{
+ struct sgx_encl_page *encl_page = req->encl_page;
+ struct sgx_encl *encl = req->encl;
+ struct sgx_secinfo secinfo;
+ struct sgx_pageinfo pginfo;
+ struct vm_area_struct *vma;
+ pgoff_t backing_index;
+ struct page *backing;
+ unsigned long addr;
+ int ret;
+ int i;
+
+ if (encl->flags & (SGX_ENCL_SUSPEND | SGX_ENCL_DEAD))
+ return false;
+
+ addr = SGX_ENCL_PAGE_ADDR(encl_page);
+ ret = sgx_encl_find(encl->mm, addr, &vma);
+ if (ret)
+ return false;
+
+ backing_index = sgx_encl_page_backing_index(encl_page, encl);
+ backing = sgx_get_backing(encl->backing, backing_index);
+ if (IS_ERR(backing))
+ return false;
+
+ ret = vmf_insert_pfn(vma, addr, PFN_DOWN(epc_page->desc));
+ if (ret != VM_FAULT_NOPAGE) {
+ sgx_put_backing(backing, false);
+ return false;
+ }
+
+ /*
+ * The SECINFO field must be 64-byte aligned, copy it to a local
+ * variable that is guaranteed to be aligned as req->secinfo may
+ * or may not be 64-byte aligned, e.g. req may have been allocated
+ * via kzalloc which is not aware of __aligned attributes.
+ */
+ memcpy(&secinfo, &req->secinfo, sizeof(secinfo));
+
+ pginfo.secs = (unsigned long)sgx_epc_addr(encl->secs.epc_page);
+ pginfo.addr = addr;
+ pginfo.metadata = (unsigned long)&secinfo;
+ pginfo.contents = (unsigned long)kmap_atomic(backing);
+ ret = __eadd(&pginfo, sgx_epc_addr(epc_page));
+ kunmap_atomic((void *)(unsigned long)pginfo.contents);
+
+ sgx_put_backing(backing, false);
+ if (ret) {
+ SGX_INVD(ret, encl, "EADD returned %d (0x%x)", ret, ret);
+ zap_vma_ptes(vma, addr, PAGE_SIZE);
+ return false;
+ }
+
+ for_each_set_bit(i, &req->mrmask, 16) {
+ ret = __eextend(sgx_epc_addr(encl->secs.epc_page),
+ sgx_epc_addr(epc_page) + (i * 0x100));
+ if (ret) {
+ SGX_INVD(ret, encl, "EEXTEND returned %d (0x%x)", ret, ret);
+ zap_vma_ptes(vma, addr, PAGE_SIZE);
+ return ret;
+ }
+ }
+
+ encl_page->encl = encl;
+ encl->secs_child_cnt++;
+ sgx_set_page_loaded(encl_page, epc_page);
+ sgx_test_and_clear_young(encl_page);
+ return true;
+}
+
+static void sgx_add_page_worker(struct work_struct *work)
+{
+ struct sgx_add_page_req *req;
+ bool skip_rest = false;
+ bool is_empty = false;
+ struct sgx_encl *encl;
+ struct sgx_epc_page *epc_page;
+
+ encl = container_of(work, struct sgx_encl, add_page_work);
+
+ do {
+ schedule();
+
+ mutex_lock(&encl->lock);
+ if (encl->flags & SGX_ENCL_DEAD)
+ skip_rest = true;
+
+ req = list_first_entry(&encl->add_page_reqs,
+ struct sgx_add_page_req, list);
+ list_del(&req->list);
+ is_empty = list_empty(&encl->add_page_reqs);
+ mutex_unlock(&encl->lock);
+
+ if (skip_rest)
+ goto next;
+
+ epc_page = sgx_alloc_page();
+ down_read(&encl->mm->mmap_sem);
+ mutex_lock(&encl->lock);
+
+ if (IS_ERR(epc_page)) {
+ sgx_invalidate(encl, false);
+ skip_rest = true;
+ } else if (!sgx_process_add_page_req(req, epc_page)) {
+ sgx_free_page(epc_page);
+ sgx_invalidate(encl, false);
+ skip_rest = true;
+ }
+
+ mutex_unlock(&encl->lock);
+ up_read(&encl->mm->mmap_sem);
+
+next:
+ kfree(req);
+ } while (!kref_put(&encl->refcount, sgx_encl_release) && !is_empty);
+}
+
+static u32 sgx_calc_ssaframesize(u32 miscselect, u64 xfrm)
+{
+ u32 size_max = PAGE_SIZE;
+ u32 size;
+ int i;
+
+ for (i = 2; i < 64; i++) {
+ if (!((1 << i) & xfrm))
+ continue;
+
+ size = SGX_SSA_GPRS_SIZE + sgx_xsave_size_tbl[i];
+ if (miscselect & SGX_MISC_EXINFO)
+ size += SGX_SSA_MISC_EXINFO_SIZE;
+
+ if (size > size_max)
+ size_max = size;
+ }
+
+ return PFN_UP(size_max);
+}
+
+static int sgx_validate_secs(const struct sgx_secs *secs,
+ unsigned long ssaframesize)
+{
+ if (secs->size < (2 * PAGE_SIZE) || !is_power_of_2(secs->size))
+ return -EINVAL;
+
+ if (secs->base & (secs->size - 1))
+ return -EINVAL;
+
+ if (secs->attributes & SGX_ATTR_RESERVED_MASK ||
+ secs->miscselect & sgx_misc_reserved)
+ return -EINVAL;
+
+ if (secs->attributes & SGX_ATTR_MODE64BIT) {
+ if (secs->size > sgx_encl_size_max_64)
+ return -EINVAL;
+ } else {
+ /* On 64-bit architecture allow 32-bit encls only in
+ * the compatibility mode.
+ */
+ if (!test_thread_flag(TIF_ADDR32))
+ return -EINVAL;
+ if (secs->size > sgx_encl_size_max_32)
+ return -EINVAL;
+ }
+
+ if (!(secs->xfrm & XFEATURE_MASK_FP) ||
+ !(secs->xfrm & XFEATURE_MASK_SSE) ||
+ (((secs->xfrm >> XFEATURE_BNDREGS) & 1) !=
+ ((secs->xfrm >> XFEATURE_BNDCSR) & 1)) ||
+ (secs->xfrm & ~sgx_xfrm_mask))
+ return -EINVAL;
+
+ if (!secs->ssa_frame_size || ssaframesize > secs->ssa_frame_size)
+ return -EINVAL;
+
+ if (memchr_inv(secs->reserved1, 0, SGX_SECS_RESERVED1_SIZE) ||
+ memchr_inv(secs->reserved2, 0, SGX_SECS_RESERVED2_SIZE) ||
+ memchr_inv(secs->reserved3, 0, SGX_SECS_RESERVED3_SIZE) ||
+ memchr_inv(secs->reserved4, 0, SGX_SECS_RESERVED4_SIZE))
+ return -EINVAL;
+
+ return 0;
+}
+
+static void sgx_mmu_notifier_release(struct mmu_notifier *mn,
+ struct mm_struct *mm)
+{
+ struct sgx_encl *encl =
+ container_of(mn, struct sgx_encl, mmu_notifier);
+
+ mutex_lock(&encl->lock);
+ encl->flags |= SGX_ENCL_DEAD;
+ mutex_unlock(&encl->lock);
+}
+
+static const struct mmu_notifier_ops sgx_mmu_notifier_ops = {
+ .release = sgx_mmu_notifier_release,
+};
+
+/**
+ * sgx_encl_alloc - allocate memory for an enclave and set attributes
+ *
+ * @secs: SECS data (must be page aligned)
+ *
+ * Allocates a new &sgx_encl instance. Validates SECS attributes, creates
+ * backing storage for the enclave and sets enclave attributes to sane initial
+ * values.
+ *
+ * Return:
+ * an &sgx_encl instance,
+ * -errno otherwise
+ */
+struct sgx_encl *sgx_encl_alloc(struct sgx_secs *secs)
+{
+ unsigned long ssaframesize;
+ struct sgx_encl *encl;
+ struct file *backing;
+
+ ssaframesize = sgx_calc_ssaframesize(secs->miscselect, secs->xfrm);
+ if (sgx_validate_secs(secs, ssaframesize))
+ return ERR_PTR(-EINVAL);
+
+ backing = shmem_file_setup("[dev/sgx]", secs->size + PAGE_SIZE,
+ VM_NORESERVE);
+ if (IS_ERR(backing))
+ return ERR_CAST(backing);
+
+ encl = kzalloc(sizeof(*encl), GFP_KERNEL);
+ if (!encl) {
+ fput(backing);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ encl->attributes = secs->attributes;
+ encl->xfrm = secs->xfrm;
+
+ kref_init(&encl->refcount);
+ INIT_LIST_HEAD(&encl->add_page_reqs);
+ INIT_RADIX_TREE(&encl->page_tree, GFP_KERNEL);
+ mutex_init(&encl->lock);
+ INIT_WORK(&encl->add_page_work, sgx_add_page_worker);
+
+ encl->mm = current->mm;
+ encl->base = secs->base;
+ encl->size = secs->size;
+ encl->ssaframesize = secs->ssa_frame_size;
+ encl->backing = backing;
+
+ return encl;
+}
+
+static int sgx_encl_pm_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct sgx_encl *encl = container_of(nb, struct sgx_encl, pm_notifier);
+
+ if (action != PM_SUSPEND_PREPARE && action != PM_HIBERNATION_PREPARE)
+ return NOTIFY_DONE;
+
+ mutex_lock(&encl->lock);
+ sgx_invalidate(encl, false);
+ encl->flags |= SGX_ENCL_SUSPEND;
+ mutex_unlock(&encl->lock);
+ flush_work(&encl->add_page_work);
+ return NOTIFY_DONE;
+}
+
+/**
+ * sgx_encl_create - create an enclave
+ *
+ * @encl: an enclave
+ * @secs: page aligned SECS data
+ *
+ * Validates SECS attributes, allocates an EPC page for the SECS and creates
+ * the enclave by performing ECREATE.
+ *
+ * Return:
+ * 0 on success,
+ * -errno otherwise
+ */
+int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs)
+{
+ struct vm_area_struct *vma;
+ struct sgx_pageinfo pginfo;
+ struct sgx_secinfo secinfo;
+ struct sgx_epc_page *secs_epc;
+ long ret;
+
+ secs_epc = sgx_alloc_page();
+ if (IS_ERR(secs_epc)) {
+ ret = PTR_ERR(secs_epc);
+ return ret;
+ }
+
+ sgx_set_page_loaded(&encl->secs, secs_epc);
+ encl->secs.encl = encl;
+ encl->tgid = get_pid(task_tgid(current));
+
+ pginfo.addr = 0;
+ pginfo.contents = (unsigned long)secs;
+ pginfo.metadata = (unsigned long)&secinfo;
+ pginfo.secs = 0;
+ memset(&secinfo, 0, sizeof(secinfo));
+ ret = __ecreate((void *)&pginfo, sgx_epc_addr(secs_epc));
+
+ if (ret) {
+ sgx_dbg(encl, "ECREATE returned %ld\n", ret);
+ return ret;
+ }
+
+ if (secs->attributes & SGX_ATTR_DEBUG)
+ encl->flags |= SGX_ENCL_DEBUG;
+
+ encl->mmu_notifier.ops = &sgx_mmu_notifier_ops;
+ ret = mmu_notifier_register(&encl->mmu_notifier, encl->mm);
+ if (ret) {
+ if (ret == -EINTR)
+ ret = -ERESTARTSYS;
+ encl->mmu_notifier.ops = NULL;
+ return ret;
+ }
+
+ encl->pm_notifier.notifier_call = &sgx_encl_pm_notifier;
+ ret = register_pm_notifier(&encl->pm_notifier);
+ if (ret) {
+ encl->pm_notifier.notifier_call = NULL;
+ return ret;
+ }
+
+ down_read(¤t->mm->mmap_sem);
+ ret = sgx_encl_find(current->mm, secs->base, &vma);
+ if (ret != -ENOENT) {
+ if (!ret)
+ ret = -EINVAL;
+ up_read(¤t->mm->mmap_sem);
+ return ret;
+ }
+
+ if (vma->vm_start != secs->base ||
+ vma->vm_end != (secs->base + secs->size) ||
+ vma->vm_pgoff != 0) {
+ ret = -EINVAL;
+ up_read(¤t->mm->mmap_sem);
+ return ret;
+ }
+
+ vma->vm_private_data = encl;
+ up_read(¤t->mm->mmap_sem);
+ return 0;
+}
+
+static int sgx_validate_secinfo(struct sgx_secinfo *secinfo)
+{
+ u64 page_type = secinfo->flags & SGX_SECINFO_PAGE_TYPE_MASK;
+ u64 perm = secinfo->flags & SGX_SECINFO_PERMISSION_MASK;
+ int i;
+
+ if ((secinfo->flags & SGX_SECINFO_RESERVED_MASK) ||
+ ((perm & SGX_SECINFO_W) && !(perm & SGX_SECINFO_R)) ||
+ (page_type != SGX_SECINFO_TCS &&
+ page_type != SGX_SECINFO_REG))
+ return -EINVAL;
+
+ for (i = 0; i < SGX_SECINFO_RESERVED_SIZE; i++)
+ if (secinfo->reserved[i])
+ return -EINVAL;
+
+ return 0;
+}
+
+static bool sgx_validate_offset(struct sgx_encl *encl, unsigned long offset)
+{
+ if (offset & (PAGE_SIZE - 1))
+ return false;
+
+ if (offset >= encl->size)
+ return false;
+
+ return true;
+}
+
+static int sgx_validate_tcs(struct sgx_encl *encl, struct sgx_tcs *tcs)
+{
+ int i;
+
+ if (tcs->flags & SGX_TCS_RESERVED_MASK)
+ return -EINVAL;
+
+ if (tcs->flags & SGX_TCS_DBGOPTIN)
+ return -EINVAL;
+
+ if (!sgx_validate_offset(encl, tcs->ssa_offset))
+ return -EINVAL;
+
+ if (!sgx_validate_offset(encl, tcs->fs_offset))
+ return -EINVAL;
+
+ if (!sgx_validate_offset(encl, tcs->gs_offset))
+ return -EINVAL;
+
+ if ((tcs->fs_limit & 0xFFF) != 0xFFF)
+ return -EINVAL;
+
+ if ((tcs->gs_limit & 0xFFF) != 0xFFF)
+ return -EINVAL;
+
+ for (i = 0; i < SGX_TCS_RESERVED_SIZE; i++)
+ if (tcs->reserved[i])
+ return -EINVAL;
+
+ return 0;
+}
+
+static int __sgx_encl_add_page(struct sgx_encl *encl,
+ struct sgx_encl_page *encl_page,
+ void *data,
+ struct sgx_secinfo *secinfo,
+ unsigned int mrmask)
+{
+ u64 page_type = secinfo->flags & SGX_SECINFO_PAGE_TYPE_MASK;
+ struct sgx_add_page_req *req = NULL;
+ pgoff_t backing_index;
+ struct page *backing;
+ void *backing_ptr;
+ int empty;
+
+ req = kzalloc(sizeof(*req), GFP_KERNEL);
+ if (!req)
+ return -ENOMEM;
+
+ backing_index = sgx_encl_page_backing_index(encl_page, encl);
+ backing = sgx_get_backing(encl->backing, backing_index);
+ if (IS_ERR(backing)) {
+ kfree(req);
+ return PTR_ERR(backing);
+ }
+ backing_ptr = kmap(backing);
+ memcpy(backing_ptr, data, PAGE_SIZE);
+ kunmap(backing);
+ if (page_type == SGX_SECINFO_TCS)
+ encl_page->desc |= SGX_ENCL_PAGE_TCS;
+ memcpy(&req->secinfo, secinfo, sizeof(*secinfo));
+ req->encl = encl;
+ req->encl_page = encl_page;
+ req->mrmask = mrmask;
+ empty = list_empty(&encl->add_page_reqs);
+ kref_get(&encl->refcount);
+ list_add_tail(&req->list, &encl->add_page_reqs);
+ if (empty)
+ queue_work(sgx_add_page_wq, &encl->add_page_work);
+ sgx_put_backing(backing, true /* write */);
+ return 0;
+}
+
+/**
+ * sgx_encl_alloc_page - allocate a new enclave page
+ * @encl: an enclave
+ * @addr: page address in the ELRANGE
+ *
+ * Return:
+ * an &sgx_encl_page instance on success,
+ * -errno otherwise
+ */
+struct sgx_encl_page *sgx_encl_alloc_page(struct sgx_encl *encl,
+ unsigned long addr)
+{
+ struct sgx_encl_page *encl_page;
+ int ret;
+
+ if (radix_tree_lookup(&encl->page_tree, PFN_DOWN(addr)))
+ return ERR_PTR(-EEXIST);
+ encl_page = kzalloc(sizeof(*encl_page), GFP_KERNEL);
+ if (!encl_page)
+ return ERR_PTR(-ENOMEM);
+ encl_page->desc = addr;
+ encl_page->encl = encl;
+ ret = radix_tree_insert(&encl->page_tree, PFN_DOWN(encl_page->desc),
+ encl_page);
+ if (ret) {
+ kfree(encl_page);
+ return ERR_PTR(ret);
+ }
+ return encl_page;
+}
+
+/**
+ * sgx_encl_free_page - free an enclave page
+ * @encl_page: an enclave page
+ */
+void sgx_encl_free_page(struct sgx_encl_page *encl_page)
+{
+ radix_tree_delete(&encl_page->encl->page_tree,
+ PFN_DOWN(encl_page->desc));
+ if (encl_page->desc & SGX_ENCL_PAGE_LOADED)
+ sgx_free_page(encl_page->epc_page);
+ kfree(encl_page);
+}
+
+/**
+ * sgx_encl_add_page - add a page to the enclave
+ *
+ * @encl: an enclave
+ * @addr: page address in the ELRANGE
+ * @data: page data
+ * @secinfo: page permissions
+ * @mrmask: bitmask to select the 256 byte chunks to be measured
+ *
+ * Creates a new enclave page and enqueues an EADD operation that will be
+ * processed by a worker thread later on.
+ *
+ * Return:
+ * 0 on success,
+ * -errno otherwise
+ */
+int sgx_encl_add_page(struct sgx_encl *encl, unsigned long addr, void *data,
+ struct sgx_secinfo *secinfo, unsigned int mrmask)
+{
+ u64 page_type = secinfo->flags & SGX_SECINFO_PAGE_TYPE_MASK;
+ struct sgx_encl_page *encl_page;
+ int ret;
+
+ if (sgx_validate_secinfo(secinfo))
+ return -EINVAL;
+ if (page_type == SGX_SECINFO_TCS) {
+ ret = sgx_validate_tcs(encl, data);
+ if (ret)
+ return ret;
+ }
+ mutex_lock(&encl->lock);
+ if (encl->flags & (SGX_ENCL_INITIALIZED | SGX_ENCL_DEAD)) {
+ mutex_unlock(&encl->lock);
+ return -EINVAL;
+ }
+ encl_page = sgx_encl_alloc_page(encl, addr);
+ if (IS_ERR(encl_page)) {
+ mutex_unlock(&encl->lock);
+ return PTR_ERR(encl_page);
+ }
+ ret = __sgx_encl_add_page(encl, encl_page, data, secinfo, mrmask);
+ if (ret)
+ sgx_encl_free_page(encl_page);
+ mutex_unlock(&encl->lock);
+ return ret;
+}
+
+static int __sgx_get_key_hash(struct crypto_shash *tfm, const void *modulus,
+ void *hash)
+{
+ SHASH_DESC_ON_STACK(shash, tfm);
+
+ shash->tfm = tfm;
+ shash->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ return crypto_shash_digest(shash, modulus, SGX_MODULUS_SIZE, hash);
+}
+
+static int sgx_get_key_hash(const void *modulus, void *hash)
+{
+ struct crypto_shash *tfm;
+ int ret;
+
+ tfm = crypto_alloc_shash("sha256", 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ ret = __sgx_get_key_hash(tfm, modulus, hash);
+
+ crypto_free_shash(tfm);
+ return ret;
+}
+
+/**
+ * sgx_encl_init - perform EINIT for the given enclave
+ *
+ * @encl: an enclave
+ * @sigstruct: SIGSTRUCT for the enclave
+ * @token: EINITTOKEN for the enclave
+ *
+ * Retries a few times in order to perform EINIT operation on an enclave
+ * because there could be potentially an interrupt storm.
+ *
+ * Return:
+ * 0 on success,
+ * SGX error code on EINIT failure,
+ * -errno otherwise
+ */
+int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct,
+ struct sgx_einittoken *token)
+{
+ u64 mrsigner[4];
+ int ret;
+ int i;
+ int j;
+
+ ret = sgx_get_key_hash(sigstruct->modulus, mrsigner);
+ if (ret)
+ return ret;
+
+ flush_work(&encl->add_page_work);
+
+ mutex_lock(&encl->lock);
+
+ if (encl->flags & SGX_ENCL_INITIALIZED) {
+ mutex_unlock(&encl->lock);
+ return 0;
+ }
+ if (encl->flags & SGX_ENCL_DEAD) {
+ mutex_unlock(&encl->lock);
+ return -EFAULT;
+ }
+
+ for (i = 0; i < SGX_EINIT_SLEEP_COUNT; i++) {
+ for (j = 0; j < SGX_EINIT_SPIN_COUNT; j++) {
+ ret = sgx_einit(sigstruct, token, encl->secs.epc_page,
+ mrsigner);
+ if (ret == SGX_UNMASKED_EVENT)
+ continue;
+ else
+ break;
+ }
+
+ if (ret != SGX_UNMASKED_EVENT)
+ break;
+
+ msleep_interruptible(SGX_EINIT_SLEEP_TIME);
+ if (signal_pending(current)) {
+ mutex_unlock(&encl->lock);
+ return -ERESTARTSYS;
+ }
+ }
+
+ if (unlikely(IS_ENCLS_FAULT(ret)))
+ SGX_INVD(ret, encl, "EINIT returned %d (%x)", ret, ret);
+ else if (ret > 0)
+ sgx_dbg(encl, "EINIT returned %d\n", ret);
+ else if (!ret)
+ encl->flags |= SGX_ENCL_INITIALIZED;
+ mutex_unlock(&encl->lock);
+
+ return ret;
+}
+
+/**
+ * sgx_encl_release - destroy an enclave instance
+ * @kref: address of a kref inside &sgx_encl
+ *
+ * Used together with kref_put(). Frees all the resources associated with the
+ * enclave and the instance itself.
+ */
+void sgx_encl_release(struct kref *ref)
+{
+ struct sgx_encl *encl = container_of(ref, struct sgx_encl, refcount);
+ struct sgx_encl_page *entry;
+ struct radix_tree_iter iter;
+ void **slot;
+
+ if (encl->mmu_notifier.ops)
+ mmu_notifier_unregister(&encl->mmu_notifier, encl->mm);
+
+ if (encl->pm_notifier.notifier_call)
+ unregister_pm_notifier(&encl->pm_notifier);
+
+ radix_tree_for_each_slot(slot, &encl->page_tree, &iter, 0) {
+ entry = *slot;
+ sgx_encl_free_page(entry);
+ }
+
+ if (encl->tgid)
+ put_pid(encl->tgid);
+
+ if (encl->secs.desc & SGX_ENCL_PAGE_LOADED)
+ sgx_free_page(encl->secs.epc_page);
+
+ if (encl->backing)
+ fput(encl->backing);
+
+ kfree(encl);
+}
diff --git a/drivers/platform/x86/intel_sgx/sgx_ioctl.c b/drivers/platform/x86/intel_sgx/sgx_ioctl.c
new file mode 100644
index 000000000000..4edf1cc956b1
--- /dev/null
+++ b/drivers/platform/x86/intel_sgx/sgx_ioctl.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2016-18 Intel Corporation.
+
+#include <asm/mman.h>
+#include <linux/delay.h>
+#include <linux/file.h>
+#include <linux/hashtable.h>
+#include <linux/highmem.h>
+#include <linux/ratelimit.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include "sgx.h"
+
+static int sgx_encl_get(unsigned long addr, struct sgx_encl **encl)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ int ret;
+
+ if (addr & (PAGE_SIZE - 1))
+ return -EINVAL;
+
+ down_read(&mm->mmap_sem);
+
+ ret = sgx_encl_find(mm, addr, &vma);
+ if (!ret) {
+ *encl = vma->vm_private_data;
+
+ if ((*encl)->flags & SGX_ENCL_SUSPEND)
+ ret = SGX_POWER_LOST_ENCLAVE;
+ else
+ kref_get(&(*encl)->refcount);
+ }
+
+ up_read(&mm->mmap_sem);
+ return ret;
+}
+
+/**
+ * sgx_ioc_enclave_create - handler for %SGX_IOC_ENCLAVE_CREATE
+ * @filep: open file to /dev/sgx
+ * @cmd: the command value
+ * @arg: pointer to an &sgx_enclave_create instance
+ *
+ * Validates SECS attributes, allocates an EPC page for the SECS and performs
+ * ECREATE.
+ *
+ * Return:
+ * 0 on success,
+ * -errno otherwise
+ */
+static long sgx_ioc_enclave_create(struct file *filep, unsigned int cmd,
+ unsigned long arg)
+{
+ struct sgx_enclave_create *createp = (struct sgx_enclave_create *)arg;
+ struct page *secs_page;
+ struct sgx_secs *secs;
+ struct sgx_encl *encl;
+ int ret;
+
+ secs_page = alloc_page(GFP_HIGHUSER);
+ if (!secs_page)
+ return -ENOMEM;
+
+ secs = kmap(secs_page);
+ ret = copy_from_user(secs, (void __user *)createp->src, sizeof(*secs));
+ if (ret)
+ goto out;
+
+ encl = sgx_encl_alloc(secs);
+ if (IS_ERR(encl)) {
+ ret = PTR_ERR(encl);
+ goto out;
+ }
+
+ ret = sgx_encl_create(encl, secs);
+ if (ret)
+ kref_put(&encl->refcount, sgx_encl_release);
+
+out:
+ kunmap(secs_page);
+ __free_page(secs_page);
+ return ret;
+}
+
+/**
+ * sgx_ioc_enclave_add_page - handler for %SGX_IOC_ENCLAVE_ADD_PAGE
+ *
+ * @filep: open file to /dev/sgx
+ * @cmd: the command value
+ * @arg: pointer to an &sgx_enclave_add_page instance
+ *
+ * Creates a new enclave page and enqueues an EADD operation that will be
+ * processed by a worker thread later on.
+ *
+ * Return:
+ * 0 on success,
+ * -errno otherwise
+ */
+static long sgx_ioc_enclave_add_page(struct file *filep, unsigned int cmd,
+ unsigned long arg)
+{
+ struct sgx_enclave_add_page *addp = (void *)arg;
+ struct sgx_secinfo secinfo;
+ struct sgx_encl *encl;
+ struct page *data_page;
+ void *data;
+ int ret;
+
+ ret = sgx_encl_get(addp->addr, &encl);
+ if (ret)
+ return ret;
+
+ if (copy_from_user(&secinfo, (void __user *)addp->secinfo,
+ sizeof(secinfo))) {
+ kref_put(&encl->refcount, sgx_encl_release);
+ return -EFAULT;
+ }
+
+ data_page = alloc_page(GFP_HIGHUSER);
+ if (!data_page) {
+ kref_put(&encl->refcount, sgx_encl_release);
+ return -ENOMEM;
+ }
+
+ data = kmap(data_page);
+
+ ret = copy_from_user((void *)data, (void __user *)addp->src, PAGE_SIZE);
+ if (ret)
+ goto out;
+
+ ret = sgx_encl_add_page(encl, addp->addr, data, &secinfo, addp->mrmask);
+ if (ret)
+ goto out;
+
+out:
+ kref_put(&encl->refcount, sgx_encl_release);
+ kunmap(data_page);
+ __free_page(data_page);
+ return ret;
+}
+
+/**
+ * sgx_ioc_enclave_init - handler for %SGX_IOC_ENCLAVE_INIT
+ *
+ * @filep: open file to /dev/sgx
+ * @cmd: the command value
+ * @arg: pointer to an &sgx_enclave_init instance
+ *
+ * Flushes the remaining enqueued EADD operations and performs EINIT. Does not
+ * allow the EINITTOKENKEY attribute for an enclave.
+ *
+ * Return:
+ * 0 on success,
+ * SGX error code on EINIT failure,
+ * -errno otherwise
+ */
+static long sgx_ioc_enclave_init(struct file *filep, unsigned int cmd,
+ unsigned long arg)
+{
+ struct sgx_enclave_init *initp = (struct sgx_enclave_init *)arg;
+ struct sgx_sigstruct *sigstruct;
+ struct sgx_einittoken *einittoken;
+ struct sgx_encl *encl;
+ struct page *initp_page;
+ int ret;
+
+ initp_page = alloc_page(GFP_HIGHUSER);
+ if (!initp_page)
+ return -ENOMEM;
+
+ sigstruct = kmap(initp_page);
+ einittoken = (struct sgx_einittoken *)
+ ((unsigned long)sigstruct + PAGE_SIZE / 2);
+ memset(einittoken, 0, sizeof(*einittoken));
+
+ ret = copy_from_user(sigstruct, (void __user *)initp->sigstruct,
+ sizeof(*sigstruct));
+ if (ret)
+ goto out;
+ if (sigstruct->attributes & SGX_ATTR_EINITTOKENKEY) {
+ ret = EINVAL;
+ goto out;
+ }
+
+ ret = sgx_encl_get(initp->addr, &encl);
+ if (ret)
+ goto out;
+
+ ret = sgx_encl_init(encl, sigstruct, einittoken);
+
+ kref_put(&encl->refcount, sgx_encl_release);
+
+out:
+ kunmap(initp_page);
+ __free_page(initp_page);
+ return ret;
+}
+
+typedef long (*sgx_ioc_t)(struct file *filep, unsigned int cmd,
+ unsigned long arg);
+
+long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
+{
+ char data[256];
+ sgx_ioc_t handler = NULL;
+ long ret;
+
+ switch (cmd) {
+ case SGX_IOC_ENCLAVE_CREATE:
+ handler = sgx_ioc_enclave_create;
+ break;
+ case SGX_IOC_ENCLAVE_ADD_PAGE:
+ handler = sgx_ioc_enclave_add_page;
+ break;
+ case SGX_IOC_ENCLAVE_INIT:
+ handler = sgx_ioc_enclave_init;
+ break;
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ if (copy_from_user(data, (void __user *)arg, _IOC_SIZE(cmd)))
+ return -EFAULT;
+
+ ret = handler(filep, cmd, (unsigned long)((void *)data));
+ if (!ret && (cmd & IOC_OUT)) {
+ if (copy_to_user((void __user *)arg, data, _IOC_SIZE(cmd)))
+ return -EFAULT;
+ }
+ if (IS_ENCLS_FAULT(ret))
+ return -EFAULT;
+ return ret;
+}
diff --git a/drivers/platform/x86/intel_sgx/sgx_main.c b/drivers/platform/x86/intel_sgx/sgx_main.c
new file mode 100644
index 000000000000..4312eab29775
--- /dev/null
+++ b/drivers/platform/x86/intel_sgx/sgx_main.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2016-18 Intel Corporation.
+
+#include <linux/acpi.h>
+#include <linux/cdev.h>
+#include <linux/platform_device.h>
+#include <linux/suspend.h>
+#include <asm/traps.h>
+#include "sgx.h"
+
+MODULE_DESCRIPTION("Intel SGX Driver");
+MODULE_AUTHOR("Jarkko Sakkinen <[email protected]>");
+MODULE_LICENSE("Dual BSD/GPL");
+
+struct workqueue_struct *sgx_add_page_wq;
+u64 sgx_encl_size_max_32;
+u64 sgx_encl_size_max_64;
+u64 sgx_xfrm_mask = 0x3;
+u32 sgx_misc_reserved;
+u32 sgx_xsave_size_tbl[64];
+int sgx_epcm_trapnr;
+
+#ifdef CONFIG_COMPAT
+long sgx_compat_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
+{
+ return sgx_ioctl(filep, cmd, arg);
+}
+#endif
+
+static int sgx_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ vma->vm_ops = &sgx_vm_ops;
+ vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP | VM_IO |
+ VM_DONTCOPY;
+
+ return 0;
+}
+
+static unsigned long sgx_get_unmapped_area(struct file *file,
+ unsigned long addr,
+ unsigned long len,
+ unsigned long pgoff,
+ unsigned long flags)
+{
+ if (len < 2 * PAGE_SIZE || (len & (len - 1)))
+ return -EINVAL;
+
+ if (len > sgx_encl_size_max_64)
+ return -EINVAL;
+
+ if (len > sgx_encl_size_max_32 && test_thread_flag(TIF_ADDR32))
+ return -EINVAL;
+
+ addr = current->mm->get_unmapped_area(file, addr, 2 * len, pgoff,
+ flags);
+ if (IS_ERR_VALUE(addr))
+ return addr;
+
+ addr = (addr + (len - 1)) & ~(len - 1);
+
+ return addr;
+}
+
+static const struct file_operations sgx_fops = {
+ .owner = THIS_MODULE,
+ .unlocked_ioctl = sgx_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = sgx_compat_ioctl,
+#endif
+ .mmap = sgx_mmap,
+ .get_unmapped_area = sgx_get_unmapped_area,
+};
+
+static struct bus_type sgx_bus_type = {
+ .name = "sgx",
+};
+
+struct sgx_context {
+ struct device dev;
+ struct cdev cdev;
+};
+
+static dev_t sgx_devt;
+
+static void sgx_dev_release(struct device *dev)
+{
+ struct sgx_context *ctx = container_of(dev, struct sgx_context, dev);
+
+ kfree(ctx);
+}
+
+static struct sgx_context *sgx_ctx_alloc(struct device *parent)
+{
+ struct sgx_context *ctx;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return ERR_PTR(-ENOMEM);
+
+ device_initialize(&ctx->dev);
+
+ ctx->dev.bus = &sgx_bus_type;
+ ctx->dev.parent = parent;
+ ctx->dev.devt = MKDEV(MAJOR(sgx_devt), 0);
+ ctx->dev.release = sgx_dev_release;
+
+ dev_set_name(&ctx->dev, "sgx");
+
+ cdev_init(&ctx->cdev, &sgx_fops);
+ ctx->cdev.owner = THIS_MODULE;
+
+ dev_set_drvdata(parent, ctx);
+
+ return ctx;
+}
+
+static struct sgx_context *sgxm_ctx_alloc(struct device *parent)
+{
+ struct sgx_context *ctx;
+ int rc;
+
+ ctx = sgx_ctx_alloc(parent);
+ if (IS_ERR(ctx))
+ return ctx;
+
+ rc = devm_add_action_or_reset(parent, (void (*)(void *))put_device,
+ &ctx->dev);
+ if (rc) {
+ kfree(ctx);
+ return ERR_PTR(rc);
+ }
+
+ return ctx;
+}
+
+static int sgx_dev_init(struct device *parent)
+{
+ struct sgx_context *sgx_dev;
+ unsigned int eax;
+ unsigned int ebx;
+ unsigned int ecx;
+ unsigned int edx;
+ int ret;
+ int i;
+
+ sgx_dev = sgxm_ctx_alloc(parent);
+
+ cpuid_count(SGX_CPUID, 0, &eax, &ebx, &ecx, &edx);
+ /* Only allow misc bits supported by the driver. */
+ sgx_misc_reserved = ~ebx | SGX_MISC_RESERVED_MASK;
+ sgx_encl_size_max_64 = 1ULL << ((edx >> 8) & 0xFF);
+ sgx_encl_size_max_32 = 1ULL << (edx & 0xFF);
+
+ if (boot_cpu_has(X86_FEATURE_OSXSAVE)) {
+ cpuid_count(SGX_CPUID, 1, &eax, &ebx, &ecx, &edx);
+ sgx_xfrm_mask = (((u64)edx) << 32) + (u64)ecx;
+
+ for (i = 2; i < 64; i++) {
+ cpuid_count(0x0D, i, &eax, &ebx, &ecx, &edx);
+ if ((1 << i) & sgx_xfrm_mask)
+ sgx_xsave_size_tbl[i] = eax + ebx;
+ }
+ }
+
+ sgx_epcm_trapnr = boot_cpu_has(X86_FEATURE_SGX2) ? X86_TRAP_PF :
+ X86_TRAP_GP;
+
+ sgx_add_page_wq = alloc_workqueue("intel_sgx-add-page-wq",
+ WQ_UNBOUND | WQ_FREEZABLE, 1);
+ if (!sgx_add_page_wq)
+ return -ENOMEM;
+
+ ret = cdev_device_add(&sgx_dev->cdev, &sgx_dev->dev);
+ if (ret)
+ goto out_workqueue;
+
+ return 0;
+out_workqueue:
+ destroy_workqueue(sgx_add_page_wq);
+ return ret;
+}
+
+static int sgx_drv_probe(struct platform_device *pdev)
+{
+ if (!boot_cpu_has(X86_FEATURE_SGX))
+ return -ENODEV;
+
+ if (!boot_cpu_has(X86_FEATURE_SGX_LC)) {
+ pr_warn("sgx: IA32_SGXLEPUBKEYHASHx MSRs are not writable\n");
+ return -ENODEV;
+ }
+
+ return sgx_dev_init(&pdev->dev);
+}
+
+static int sgx_drv_remove(struct platform_device *pdev)
+{
+ struct sgx_context *ctx = dev_get_drvdata(&pdev->dev);
+
+ cdev_device_del(&ctx->cdev, &ctx->dev);
+ destroy_workqueue(sgx_add_page_wq);
+
+ return 0;
+}
+
+#ifdef CONFIG_ACPI
+static struct acpi_device_id sgx_device_ids[] = {
+ {"INT0E0C", 0},
+ {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, sgx_device_ids);
+#endif
+
+static struct platform_driver sgx_drv = {
+ .probe = sgx_drv_probe,
+ .remove = sgx_drv_remove,
+ .driver = {
+ .name = "intel_sgx",
+ .acpi_match_table = ACPI_PTR(sgx_device_ids),
+ },
+};
+
+static int __init sgx_drv_subsys_init(void)
+{
+ int ret;
+
+ ret = bus_register(&sgx_bus_type);
+ if (ret)
+ return ret;
+
+ ret = alloc_chrdev_region(&sgx_devt, 0, 1, "sgx");
+ if (ret < 0) {
+ bus_unregister(&sgx_bus_type);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void sgx_drv_subsys_exit(void)
+{
+ bus_unregister(&sgx_bus_type);
+ unregister_chrdev_region(sgx_devt, 1);
+}
+
+static int __init sgx_drv_init(void)
+{
+ int ret;
+
+ ret = sgx_drv_subsys_init();
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&sgx_drv);
+ if (ret)
+ sgx_drv_subsys_exit();
+
+ return ret;
+}
+module_init(sgx_drv_init);
+
+static void __exit sgx_drv_exit(void)
+{
+ platform_driver_unregister(&sgx_drv);
+ sgx_drv_subsys_exit();
+}
+module_exit(sgx_drv_exit);
diff --git a/drivers/platform/x86/intel_sgx/sgx_util.c b/drivers/platform/x86/intel_sgx/sgx_util.c
new file mode 100644
index 000000000000..cbea4c0e794b
--- /dev/null
+++ b/drivers/platform/x86/intel_sgx/sgx_util.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2016-18 Intel Corporation.
+
+#include <linux/mm.h>
+#include <linux/shmem_fs.h>
+#include "sgx.h"
+
+static int sgx_test_and_clear_young_cb(pte_t *ptep, pgtable_t token,
+ unsigned long addr, void *data)
+{
+ pte_t pte;
+ int ret;
+
+ ret = pte_young(*ptep);
+ if (ret) {
+ pte = pte_mkold(*ptep);
+ set_pte_at((struct mm_struct *)data, addr, ptep, pte);
+ }
+
+ return ret;
+}
+
+/**
+ * sgx_test_and_clear_young() - Test and reset the accessed bit
+ * @page: enclave page to be tested for recent access
+ *
+ * Checks the Access (A) bit from the PTE corresponding to the
+ * enclave page and clears it. Returns 1 if the page has been
+ * recently accessed and 0 if not.
+ */
+int sgx_test_and_clear_young(struct sgx_encl_page *page)
+{
+ unsigned long addr = SGX_ENCL_PAGE_ADDR(page);
+ struct sgx_encl *encl = page->encl;
+ struct vm_area_struct *vma;
+ int ret;
+
+ ret = sgx_encl_find(encl->mm, addr, &vma);
+ if (ret)
+ return 0;
+
+ if (encl != vma->vm_private_data)
+ return 0;
+
+ return apply_to_page_range(vma->vm_mm, addr, PAGE_SIZE,
+ sgx_test_and_clear_young_cb, vma->vm_mm);
+}
+
+static void sgx_ipi_cb(void *info)
+{
+}
+
+void sgx_flush_cpus(struct sgx_encl *encl)
+{
+ on_each_cpu_mask(mm_cpumask(encl->mm), sgx_ipi_cb, NULL, 1);
+}
+
+/**
+ * sgx_set_page_loaded - associate an EPC page with an enclave page
+ * @encl_page: an enclave page
+ * @epc_page: the EPC page to attach to @encl_page
+ */
+void sgx_set_page_loaded(struct sgx_encl_page *encl_page,
+ struct sgx_epc_page *epc_page)
+{
+ encl_page->desc |= SGX_ENCL_PAGE_LOADED;
+ encl_page->epc_page = epc_page;
+}
+
+struct page *sgx_get_backing(struct file *file, pgoff_t index)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct address_space *mapping = inode->i_mapping;
+ gfp_t gfpmask = mapping_gfp_mask(mapping);
+
+ return shmem_read_mapping_page_gfp(mapping, index, gfpmask);
+}
+
+void sgx_put_backing(struct page *backing_page, bool write)
+{
+ if (write)
+ set_page_dirty(backing_page);
+
+ put_page(backing_page);
+}
diff --git a/drivers/platform/x86/intel_sgx/sgx_vma.c b/drivers/platform/x86/intel_sgx/sgx_vma.c
new file mode 100644
index 000000000000..17e95a0c734c
--- /dev/null
+++ b/drivers/platform/x86/intel_sgx/sgx_vma.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2016-18 Intel Corporation.
+
+#include <asm/mman.h>
+#include <linux/delay.h>
+#include <linux/file.h>
+#include <linux/hashtable.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/ratelimit.h>
+#include <linux/slab.h>
+#include "sgx.h"
+
+static void sgx_vma_open(struct vm_area_struct *vma)
+{
+ struct sgx_encl *encl = vma->vm_private_data;
+
+ if (!encl)
+ return;
+
+ /* kref cannot underflow because ECREATE ioctl checks that there is only
+ * one single VMA for the enclave before proceeding.
+ */
+ kref_get(&encl->refcount);
+}
+
+static void sgx_vma_close(struct vm_area_struct *vma)
+{
+ struct sgx_encl *encl = vma->vm_private_data;
+
+ if (!encl)
+ return;
+
+ mutex_lock(&encl->lock);
+ sgx_invalidate(encl, true);
+ mutex_unlock(&encl->lock);
+ kref_put(&encl->refcount, sgx_encl_release);
+}
+
+const struct vm_operations_struct sgx_vm_ops = {
+ .close = sgx_vma_close,
+ .open = sgx_vma_open,
+};
--
2.19.1
Add VMA callbacks for ptrace() that can be used with debug enclaves.
With debug enclaves data can be read and write the memory word at a time
by using ENCLS(EDBGRD) and ENCLS(EDBGWR) leaf instructions.
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
drivers/platform/x86/intel_sgx/sgx_vma.c | 109 +++++++++++++++++++++++
1 file changed, 109 insertions(+)
diff --git a/drivers/platform/x86/intel_sgx/sgx_vma.c b/drivers/platform/x86/intel_sgx/sgx_vma.c
index cc0993b4fd40..df604e4d0d0a 100644
--- a/drivers/platform/x86/intel_sgx/sgx_vma.c
+++ b/drivers/platform/x86/intel_sgx/sgx_vma.c
@@ -51,8 +51,117 @@ static int sgx_vma_fault(struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
}
+static int sgx_edbgrd(struct sgx_encl *encl, struct sgx_encl_page *page,
+ unsigned long addr, void *data)
+{
+ unsigned long offset;
+ int ret;
+
+ offset = addr & ~PAGE_MASK;
+
+ if ((page->desc & SGX_ENCL_PAGE_TCS) &&
+ offset > offsetof(struct sgx_tcs, gs_limit))
+ return -ECANCELED;
+
+ ret = __edbgrd(sgx_epc_addr(page->epc_page) + offset, data);
+ if (ret) {
+ sgx_dbg(encl, "EDBGRD returned %d\n", ret);
+ return encls_to_err(ret);
+ }
+
+ return 0;
+}
+
+static int sgx_edbgwr(struct sgx_encl *encl, struct sgx_encl_page *page,
+ unsigned long addr, void *data)
+{
+ unsigned long offset;
+ int ret;
+
+ offset = addr & ~PAGE_MASK;
+
+ /* Writing anything else than flags will cause #GP */
+ if ((page->desc & SGX_ENCL_PAGE_TCS) &&
+ offset != offsetof(struct sgx_tcs, flags))
+ return -ECANCELED;
+
+ ret = __edbgwr(sgx_epc_addr(page->epc_page) + offset, data);
+ if (ret) {
+ sgx_dbg(encl, "EDBGWR returned %d\n", ret);
+ return encls_to_err(ret);
+ }
+
+ return 0;
+}
+
+static int sgx_vma_access(struct vm_area_struct *vma, unsigned long addr,
+ void *buf, int len, int write)
+{
+ struct sgx_encl *encl = vma->vm_private_data;
+ struct sgx_encl_page *entry = NULL;
+ unsigned long align;
+ char data[sizeof(unsigned long)];
+ int offset;
+ int cnt;
+ int ret = 0;
+ int i;
+
+ /* If process was forked, VMA is still there but vm_private_data is set
+ * to NULL.
+ */
+ if (!encl)
+ return -EFAULT;
+
+ if (!(encl->flags & SGX_ENCL_DEBUG) ||
+ !(encl->flags & SGX_ENCL_INITIALIZED) ||
+ (encl->flags & SGX_ENCL_DEAD))
+ return -EFAULT;
+
+ for (i = 0; i < len; i += cnt) {
+ if (!entry || !((addr + i) & (PAGE_SIZE - 1))) {
+ if (entry)
+ entry->desc &= ~SGX_ENCL_PAGE_RESERVED;
+
+ entry = sgx_fault_page(vma, (addr + i) & PAGE_MASK,
+ true);
+ if (IS_ERR(entry)) {
+ ret = PTR_ERR(entry);
+ entry = NULL;
+ break;
+ }
+ }
+
+ /* Locking is not needed because only immutable fields of the
+ * page are accessed and page itself is reserved so that it
+ * cannot be swapped out in the middle.
+ */
+
+ align = ALIGN_DOWN(addr + i, sizeof(unsigned long));
+ offset = (addr + i) & (sizeof(unsigned long) - 1);
+ cnt = sizeof(unsigned long) - offset;
+ cnt = min(cnt, len - i);
+
+ ret = sgx_edbgrd(encl, entry, align, data);
+ if (ret)
+ break;
+ if (write) {
+ memcpy(data + offset, buf + i, cnt);
+ ret = sgx_edbgwr(encl, entry, align, data);
+ if (ret)
+ break;
+ } else
+ memcpy(buf + i, data + offset, cnt);
+ }
+
+ if (entry)
+ entry->desc &= ~SGX_ENCL_PAGE_RESERVED;
+
+ return ret < 0 ? ret : i;
+}
+
const struct vm_operations_struct sgx_vm_ops = {
.close = sgx_vma_close,
.open = sgx_vma_open,
.fault = sgx_vma_fault,
+ .access = sgx_vma_access,
};
--
2.19.1
From: Sean Christopherson <[email protected]>
Add a helper function to perform ENCLS(EINIT) with the correct LE
hash MSR values. ENCLS[EINIT] initializes an enclave, verifying the
enclave's measurement and preparing it for execution, i.e. the enclave
cannot be run until it has been initialized. The measurement aspect
of EINIT references the MSR_IA32_SGXLEPUBKEYHASH* MSRs, with the CPU
comparing CPU compares the key (technically its hash) used to sign the
enclave[1] with the key hash stored in the MSRs, and will reject EINIT
if the keys do not match.
A per-cpu cache is used to avoid writing the MSRs as writing the MSRs
is extraordinarily expensive, e.g. 300-400 cycles per MSR. Because
the cache may become stale, force update the MSRs and retry EINIT if
the first EINIT fails due to an "invalid token". An invalid token
error does not necessarily mean the MSRs need to be updated, but the
cost of an unnecessary write is minimal relative to the cost of EINIT
itself.
[1] For EINIT's purposes, the effective signer of the enclave may be
the enclave's owner, or a separate Launch Enclave that has created
an EINIT token for the target enclave. When using an EINIT token,
the key used to sign the token must match the MSRs in order for
EINIT to succeed.
Signed-off-by: Sean Christopherson <[email protected]>
Co-developed-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
arch/x86/include/asm/sgx.h | 2 ++
arch/x86/kernel/cpu/intel_sgx.c | 50 +++++++++++++++++++++++++++++++++
2 files changed, 52 insertions(+)
diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index 4e39bcfad018..b6f014d0d88d 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -312,5 +312,7 @@ static inline int __emodt(struct sgx_secinfo *secinfo, void __iomem *addr)
struct sgx_epc_page *sgx_alloc_page(void);
int __sgx_free_page(struct sgx_epc_page *page);
void sgx_free_page(struct sgx_epc_page *page);
+int sgx_einit(struct sgx_sigstruct *sigstruct, struct sgx_einittoken *token,
+ struct sgx_epc_page *secs, u64 *lepubkeyhash);
#endif /* _ASM_X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/intel_sgx.c b/arch/x86/kernel/cpu/intel_sgx.c
index b06709a9ea65..19041e96d1da 100644
--- a/arch/x86/kernel/cpu/intel_sgx.c
+++ b/arch/x86/kernel/cpu/intel_sgx.c
@@ -15,6 +15,9 @@ EXPORT_SYMBOL_GPL(sgx_epc_sections);
static int sgx_nr_epc_sections;
+/* A per-cpu cache for the last known values of IA32_SGXLEPUBKEYHASHx MSRs. */
+static DEFINE_PER_CPU(u64 [4], sgx_lepubkeyhash_cache);
+
/**
* sgx_alloc_page - Allocate an EPC page
*
@@ -91,6 +94,53 @@ void sgx_free_page(struct sgx_epc_page *page)
}
EXPORT_SYMBOL_GPL(sgx_free_page);
+static void sgx_update_lepubkeyhash_msrs(u64 *lepubkeyhash, bool enforce)
+{
+ u64 __percpu *cache;
+ int i;
+
+ cache = per_cpu(sgx_lepubkeyhash_cache, smp_processor_id());
+ for (i = 0; i < 4; i++) {
+ if (enforce || (lepubkeyhash[i] != cache[i])) {
+ wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]);
+ cache[i] = lepubkeyhash[i];
+ }
+ }
+}
+
+/**
+ * sgx_einit - initialize an enclave
+ * @sigstruct: a pointer a SIGSTRUCT
+ * @token: a pointer an EINITTOKEN (optional)
+ * @secs: a pointer a SECS
+ * @lepubkeyhash: the desired value for IA32_SGXLEPUBKEYHASHx MSRs
+ *
+ * Execute ENCLS[EINIT], writing the IA32_SGXLEPUBKEYHASHx MSRs according
+ * to @lepubkeyhash (if possible and necessary).
+ *
+ * Return:
+ * 0 on success,
+ * -errno or SGX error on failure
+ */
+int sgx_einit(struct sgx_sigstruct *sigstruct, struct sgx_einittoken *token,
+ struct sgx_epc_page *secs, u64 *lepubkeyhash)
+{
+ int ret;
+
+ if (!boot_cpu_has(X86_FEATURE_SGX_LC))
+ return __einit(sigstruct, token, sgx_epc_addr(secs));
+
+ preempt_disable();
+ sgx_update_lepubkeyhash_msrs(lepubkeyhash, false);
+ ret = __einit(sigstruct, token, sgx_epc_addr(secs));
+ if (ret == SGX_INVALID_EINITTOKEN) {
+ sgx_update_lepubkeyhash_msrs(lepubkeyhash, true);
+ ret = __einit(sigstruct, token, sgx_epc_addr(secs));
+ }
+ preempt_enable();
+ return ret;
+}
+EXPORT_SYMBOL(sgx_einit);
static __init void sgx_free_epc_section(struct sgx_epc_section *section)
{
--
2.19.1
Documentation of the features of the Software Guard eXtensions used
by the Linux kernel and basic design choices for the core and driver
and functionality.
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
Documentation/index.rst | 1 +
Documentation/x86/intel_sgx.rst | 185 ++++++++++++++++++++++++++++++++
2 files changed, 186 insertions(+)
create mode 100644 Documentation/x86/intel_sgx.rst
diff --git a/Documentation/index.rst b/Documentation/index.rst
index 5db7e87c7cb1..1cdc139adb40 100644
--- a/Documentation/index.rst
+++ b/Documentation/index.rst
@@ -104,6 +104,7 @@ implementation.
:maxdepth: 2
sh/index
+ x86/index
Filesystem Documentation
------------------------
diff --git a/Documentation/x86/intel_sgx.rst b/Documentation/x86/intel_sgx.rst
new file mode 100644
index 000000000000..f6b7979c41f2
--- /dev/null
+++ b/Documentation/x86/intel_sgx.rst
@@ -0,0 +1,185 @@
+===================
+Intel(R) SGX driver
+===================
+
+Introduction
+============
+
+Intel(R) SGX is a set of CPU instructions that can be used by applications to
+set aside private regions of code and data. The code outside the enclave is
+disallowed to access the memory inside the enclave by the CPU access control.
+In a way you can think that SGX provides inverted sandbox. It protects the
+application from a malicious host.
+
+You can tell if your CPU supports SGX by looking into ``/proc/cpuinfo``:
+
+ ``cat /proc/cpuinfo | grep sgx``
+
+Overview of SGX
+===============
+
+SGX has a set of data structures to maintain information about the enclaves and
+their security properties. BIOS reserves a fixed size region of physical memory
+for these structures by setting Processor Reserved Memory Range Registers
+(PRMRR).
+
+This memory range is protected from outside access by the CPU and all the data
+coming in and out of the CPU package is encrypted by a key that is generated for
+each boot cycle.
+
+Enclaves execute in ring-3 in a special enclave submode using pages from the
+reserved memory range. A fixed logical address range for the enclave is reserved
+by ENCLS(ECREATE), a leaf instruction used to create enclaves. It is referred in
+the documentation commonly as the ELRANGE.
+
+Every memory access to the ELRANGE is asserted by the CPU. If the CPU is not
+executing in the enclave mode inside the enclave, #GP is raised. On the other
+hand enclave code can make memory accesses both inside and outside of the
+ELRANGE.
+
+Enclave can only execute code inside the ELRANGE. Instructions that may cause
+VMEXIT, IO instructions and instructions that require a privilege change are
+prohibited inside the enclave. Interrupts and exceptions always cause enclave
+to exit and jump to an address outside the enclave given when the enclave is
+entered by using the leaf instruction ENCLS(EENTER).
+
+Data types
+----------
+
+The protected memory range contains the following data:
+
+* **Enclave Page Cache (EPC):** protected pages
+* **Enclave Page Cache Map (EPCM):** a database that describes the state of the
+ pages and link them to an enclave.
+
+EPC has a number of different types of pages:
+
+* **SGX Enclave Control Structure (SECS)**: describes the global
+ properties of an enclave.
+* **Regular (REG):** code and data pages in the ELRANGE.
+* **Thread Control Structure (TCS):** pages that define entry points inside an
+ enclave. The enclave can only be entered through these entry points and each
+ can host a single hardware thread at a time.
+* **Version Array (VA)**: 64-bit version numbers for pages that have been
+ swapped outside the enclave. Each page contains 512 version numbers.
+
+Launch control
+--------------
+
+To launch an enclave, two structures must be provided for ENCLS(EINIT):
+
+1. **SIGSTRUCT:** signed measurement of the enclave binary.
+2. **EINITTOKEN:** a cryptographic token CMAC-signed with a AES256-key called
+ *launch key*, which is re-generated for each boot cycle.
+
+The CPU holds a SHA256 hash of a 3072-bit RSA public key inside
+IA32_SGXLEPUBKEYHASHn MSRs. Enclaves with a SIGSTRUCT that is signed with this
+key do not require a valid EINITTOKEN and can be authorized with special
+privileges. One of those privileges is ability to acquire the launch key with
+ENCLS(EGETKEY).
+
+**IA32_FEATURE_CONTROL[17]** is used by the BIOS configure whether
+IA32_SGXLEPUBKEYHASH MSRs are read-only or read-write before locking the
+feature control register and handing over control to the operating system.
+
+Enclave construction
+--------------------
+
+The construction is started by filling out the SECS that contains enclave
+address range, privileged attributes and measurement of TCS and REG pages (pages
+that will be mapped to the address range) among the other things. This structure
+is passed out to the ENCLS(ECREATE) together with a physical address of a page
+in EPC that will hold the SECS.
+
+The pages are added with ENCLS(EADD) and measured with ENCLS(EEXTEND) i.e.
+SHA256 hash MRENCLAVE residing in the SECS is extended with the page data.
+
+After all of the pages have been added, the enclave is initialized with
+ENCLS(EINIT). ENCLS(INIT) checks that the SIGSTRUCT is signed with the contained
+public key. If the given EINITTOKEN has the valid bit set, the CPU checks that
+the token is valid (CMAC'd with the launch key). If the token is not valid,
+the CPU will check whether the enclave is signed with a key matching to the
+IA32_SGXLEPUBKEYHASHn MSRs.
+
+Swapping pages
+--------------
+
+Enclave pages can be swapped out with ENCLS(EWB) to the unprotected memory. In
+addition to the EPC page, ENCLS(EWB) takes in a VA page and address for PCMD
+structure (Page Crypto MetaData) as input. The VA page will seal a version
+number for the page. PCMD is 128 byte structure that contains tracking
+information for the page, most importantly its MAC. With these structures the
+enclave is sealed and rollback protected while it resides in the unprotected
+memory.
+
+Before the page can be swapped out it must not have any active TLB references.
+ENCLS(EBLOCK) instruction moves a page to the *blocked* state, which means
+that no new TLB entries can be created to it by the hardware threads.
+
+After this a shootdown sequence is started with ENCLS(ETRACK), which sets an
+increased counter value to the entering hardware threads. ENCLS(EWB) will
+return SGX_NOT_TRACKED error while there are still threads with the earlier
+couner value because that means that there might be hardware thread inside
+the enclave with TLB entries to pages that are to be swapped.
+
+Kernel internals
+================
+
+Requirements
+------------
+
+Because SGX has an ever evolving and expanding feature set, it's possible for
+a BIOS or VMM to configure a system in such a way that not all CPUs are equal,
+e.g. where Launch Control is only enabled on a subset of CPUs. Linux does
+*not* support such a heterogeneous system configuration, nor does it even
+attempt to play nice in the face of a misconfigured system. With the exception
+of Launch Control's hash MSRs, which can vary per CPU, Linux assumes that all
+CPUs have a configuration that is identical to the boot CPU.
+
+
+Roles and responsibilities
+--------------------------
+
+SGX introduces system resources, e.g. EPC memory, that must be accessible to
+multiple entities, e.g. the native kernel driver (to expose SGX to userspace)
+and KVM (to expose SGX to VMs), ideally without introducing any dependencies
+between each SGX entity. To that end, the kernel owns and manages the shared
+system resources, i.e. the EPC and Launch Control MSRs, and defines functions
+that provide appropriate access to the shared resources. SGX support for
+user space and VMs is left to the SGX platform driver and KVM respectively.
+
+Launching enclaves
+------------------
+
+The current kernel implementation supports only unlocked MSRs i.e.
+FEATURE_CONTROL_SGX_LE_WR must be set. The launch is performed by setting the
+MSRs to the hash of the public key modulus of the enclave signer, which is one
+f the fields in the SIGSTRUCT.
+
+EPC management
+--------------
+
+Due to the unique requirements for swapping EPC pages, and because EPC pages
+(currently) do not have associated page structures, management of the EPC is
+not handled by the standard Linux swapper. SGX directly handles swapping
+of EPC pages, including a kthread to initiate reclaim and a rudimentary LRU
+mechanism. The consumers of EPC pages, e.g. the SGX driver, are required to
+implement function callbacks that can be invoked by the kernel to age,
+swap, and/or forcefully reclaim a target EPC page. In effect, the kernel
+controls what happens and when, while the consumers (driver, KVM, etc..) do
+the actual work.
+
+SGX uapi
+========
+
+.. kernel-doc:: drivers/platform/x86/intel_sgx/sgx_ioctl.c
+ :functions: sgx_ioc_enclave_create
+ sgx_ioc_enclave_add_page
+ sgx_ioc_enclave_init
+
+.. kernel-doc:: arch/x86/include/uapi/asm/sgx.h
+
+References
+==========
+
+* System Programming Manual: 39.1.4 Intel® SGX Launch Control Configuration
--
2.19.1
Wire up the EPC manager's reclaim flow to the SGX driver's swapping
functionality. In the long term there will be multiple users of the
EPC manager, e.g. SGX driver and KVM, thus the interface between the
EPC manager and the driver is fairly genericized and decoupled. But
to avoid adding unusued infrastructure, do not add any indirection
between the EPC manager and the SGX driver. This has the unfortunate
and odd side effect of preventing the SGX driver from being compiled
as a loadable module. However, this should be a temporary situation
that is remedied when a second user of EPC is added, i.e. KVM.
The swapper thread ksgxswapd reclaims pages on the event when the number
of free EPC pages goes below %SGX_NR_LOW_PAGES up until it reaches
%SGX_NR_HIGH_PAGES.
Pages are reclaimed in LRU fashion from a global list. The consumers
take care of calling EBLOCK (block page from new accesses), ETRACK
(restart counting the entering hardware threads) and EWB (write page to
the regular memory) because executing these operations usually (if not
always) requires to do some subsystem-internal locking operations.
Signed-off-by: Jarkko Sakkinen <[email protected]>
Co-developed-by: Sean Christopherson <[email protected]>
Co-developed-by: Serge Ayoun <[email protected]>
Co-developed-by: Shay Katz-zamir <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Serge Ayoun <[email protected]>
Signed-off-by: Shay Katz-zamir <[email protected]>
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/sgx.h | 10 +-
arch/x86/kernel/cpu/intel_sgx.c | 241 +++++++++++++++++-
drivers/platform/x86/intel_sgx/sgx_encl.c | 5 +-
.../platform/x86/intel_sgx/sgx_encl_page.c | 3 +-
drivers/platform/x86/intel_sgx/sgx_fault.c | 3 +-
drivers/platform/x86/intel_sgx/sgx_util.c | 2 +-
7 files changed, 245 insertions(+), 20 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b47e1a144409..5c329dfd0fd9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1916,6 +1916,7 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS
config INTEL_SGX_CORE
bool "Intel SGX core functionality"
depends on X86_64 && CPU_SUP_INTEL
+ select INTEL_SGX
help
Intel Software Guard eXtensions (SGX) CPU feature that allows ring 3
applications to create enclaves: private regions of memory that are
diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index b6f014d0d88d..865e753e7745 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -14,6 +14,7 @@
struct sgx_epc_page {
unsigned long desc;
+ void *owner;
struct list_head list;
};
@@ -309,10 +310,17 @@ static inline int __emodt(struct sgx_secinfo *secinfo, void __iomem *addr)
return __encls_ret_2(SGX_EMODT, secinfo, addr);
}
-struct sgx_epc_page *sgx_alloc_page(void);
+struct sgx_epc_page *sgx_alloc_page(void *owner, bool reclaim);
int __sgx_free_page(struct sgx_epc_page *page);
void sgx_free_page(struct sgx_epc_page *page);
int sgx_einit(struct sgx_sigstruct *sigstruct, struct sgx_einittoken *token,
struct sgx_epc_page *secs, u64 *lepubkeyhash);
+void sgx_page_reclaimable(struct sgx_epc_page *page);
+
+bool sgx_encl_page_get(struct sgx_epc_page *epc_page);
+void sgx_encl_page_put(struct sgx_epc_page *epc_page);
+bool sgx_encl_page_reclaim(struct sgx_epc_page *epc_page);
+void sgx_encl_page_block(struct sgx_epc_page *epc_page);
+void sgx_encl_page_write(struct sgx_epc_page *epc_page);
#endif /* _ASM_X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/intel_sgx.c b/arch/x86/kernel/cpu/intel_sgx.c
index 19041e96d1da..cc8c4a1e6650 100644
--- a/arch/x86/kernel/cpu/intel_sgx.c
+++ b/arch/x86/kernel/cpu/intel_sgx.c
@@ -10,24 +10,141 @@
#include <linux/slab.h>
#include <asm/sgx.h>
+/**
+ * enum sgx_swap_constants - the constants used by the swapping code
+ * %SGX_NR_TO_SCAN: the number of pages to scan in a single round
+ * %SGX_NR_LOW_PAGES: the low watermark for ksgxswapd when it starts to swap
+ * pages.
+ * %SGX_NR_HIGH_PAGES: the high watermark for ksgxswapd what it stops swapping
+ * pages.
+ */
+enum sgx_swap_constants {
+ SGX_NR_TO_SCAN = 16,
+ SGX_NR_LOW_PAGES = 32,
+ SGX_NR_HIGH_PAGES = 64,
+};
+
struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS];
EXPORT_SYMBOL_GPL(sgx_epc_sections);
static int sgx_nr_epc_sections;
+static LIST_HEAD(sgx_active_page_list);
+static DEFINE_SPINLOCK(sgx_active_page_list_lock);
+static struct task_struct *ksgxswapd_tsk;
+static DECLARE_WAIT_QUEUE_HEAD(ksgxswapd_waitq);
/* A per-cpu cache for the last known values of IA32_SGXLEPUBKEYHASHx MSRs. */
static DEFINE_PER_CPU(u64 [4], sgx_lepubkeyhash_cache);
/**
- * sgx_alloc_page - Allocate an EPC page
- *
- * Try to grab a page from the free EPC page list.
+ * sgx_reclaim_pages - reclaim EPC pages from the consumers
*
- * Return:
- * a pointer to a &struct sgx_epc_page instance,
- * -errno on error
+ * Takes a fixed chunk of pages from the global list of consumed EPC pages and
+ * tries to swap them. Only the pages that are either being freed by the
+ * consumer or actively used are skipped.
*/
-struct sgx_epc_page *sgx_alloc_page(void)
+static void sgx_reclaim_pages(void)
+{
+ struct sgx_epc_page *chunk[SGX_NR_TO_SCAN + 1];
+ struct sgx_epc_page *epc_page;
+ struct sgx_epc_section *section;
+ int i, j;
+
+ spin_lock(&sgx_active_page_list_lock);
+ for (i = 0, j = 0; i < SGX_NR_TO_SCAN; i++) {
+ if (list_empty(&sgx_active_page_list))
+ break;
+
+ epc_page = list_first_entry(&sgx_active_page_list,
+ struct sgx_epc_page, list);
+ list_del_init(&epc_page->list);
+
+ if (sgx_encl_page_get(epc_page))
+ chunk[j++] = epc_page;
+ else
+ /* The owner is freeing the page. No need to add the
+ * page back to the list of reclaimable pages.
+ */
+ epc_page->desc &= ~SGX_EPC_PAGE_RECLAIMABLE;
+ }
+ spin_unlock(&sgx_active_page_list_lock);
+
+ for (i = 0; i < j; i++) {
+ epc_page = chunk[i];
+ if (sgx_encl_page_reclaim(epc_page))
+ continue;
+
+ sgx_encl_page_put(epc_page);
+
+ spin_lock(&sgx_active_page_list_lock);
+ list_add_tail(&epc_page->list, &sgx_active_page_list);
+ spin_unlock(&sgx_active_page_list_lock);
+
+ chunk[i] = NULL;
+ }
+
+ for (i = 0; i < j; i++) {
+ epc_page = chunk[i];
+ if (epc_page)
+ sgx_encl_page_block(epc_page);
+ }
+
+ for (i = 0; i < j; i++) {
+ epc_page = chunk[i];
+ if (epc_page) {
+ sgx_encl_page_write(epc_page);
+ sgx_encl_page_put(epc_page);
+ epc_page->desc &= ~SGX_EPC_PAGE_RECLAIMABLE;
+
+ section = sgx_epc_section(epc_page);
+ spin_lock(§ion->lock);
+ section->pages[section->free_cnt++] = epc_page;
+ spin_unlock(§ion->lock);
+ }
+ }
+}
+
+static unsigned long sgx_calc_free_cnt(void)
+{
+ struct sgx_epc_section *section;
+ unsigned long free_cnt = 0;
+ int i;
+
+ for (i = 0; i < sgx_nr_epc_sections; i++) {
+ section = &sgx_epc_sections[i];
+ free_cnt += section->free_cnt;
+ }
+
+ return free_cnt;
+}
+
+static inline bool sgx_should_reclaim(void)
+{
+ return sgx_calc_free_cnt() < SGX_NR_HIGH_PAGES &&
+ !list_empty(&sgx_active_page_list);
+}
+
+static int ksgxswapd(void *p)
+{
+ set_freezable();
+
+ while (!kthread_should_stop()) {
+ if (try_to_freeze())
+ continue;
+
+ wait_event_freezable(ksgxswapd_waitq, kthread_should_stop() ||
+ sgx_should_reclaim());
+
+ if (sgx_should_reclaim())
+ sgx_reclaim_pages();
+
+ cond_resched();
+ }
+
+ return 0;
+}
+
+static struct sgx_epc_page *sgx_try_alloc_page(void *owner)
{
struct sgx_epc_section *section;
struct sgx_epc_page *page;
@@ -42,11 +159,58 @@ struct sgx_epc_page *sgx_alloc_page(void)
}
spin_unlock(§ion->lock);
- if (page)
+ if (page) {
+ page->owner = owner;
return page;
+ }
}
- return ERR_PTR(-ENOMEM);
+ return NULL;
+}
+
+/**
+ * sgx_alloc_page - Allocate an EPC page
+ * @owner: the owner of the EPC page
+ * @reclaim: reclaim pages if necessary
+ *
+ * Try to grab a page from the free EPC page list. If there is a free page
+ * available, it is returned to the caller. The @reclaim parameter hints
+ * the EPC memory manager to swap pages when required.
+ *
+ * Return:
+ * a pointer to a &struct sgx_epc_page instance,
+ * -errno on error
+ */
+struct sgx_epc_page *sgx_alloc_page(void *owner, bool reclaim)
+{
+ struct sgx_epc_page *entry;
+
+ for ( ; ; ) {
+ entry = sgx_try_alloc_page(owner);
+ if (entry)
+ break;
+
+ if (list_empty(&sgx_active_page_list))
+ return ERR_PTR(-ENOMEM);
+
+ if (!reclaim) {
+ entry = ERR_PTR(-EBUSY);
+ break;
+ }
+
+ if (signal_pending(current)) {
+ entry = ERR_PTR(-ERESTARTSYS);
+ break;
+ }
+
+ sgx_reclaim_pages();
+ schedule();
+ }
+
+ if (sgx_calc_free_cnt() < SGX_NR_LOW_PAGES)
+ wake_up(&ksgxswapd_waitq);
+
+ return entry;
}
EXPORT_SYMBOL_GPL(sgx_alloc_page);
@@ -54,10 +218,12 @@ EXPORT_SYMBOL_GPL(sgx_alloc_page);
* __sgx_free_page - Free an EPC page
* @page: pointer a previously allocated EPC page
*
- * EREMOVE an EPC page and insert it back to the list of free pages.
+ * EREMOVE an EPC page and insert it back to the list of free pages. If the
+ * page is reclaimable, delete it from the active page list.
*
* Return:
* 0 on success
+ * -EBUSY if the page cannot be removed from the active list
* SGX error code if EREMOVE fails
*/
int __sgx_free_page(struct sgx_epc_page *page)
@@ -65,6 +231,23 @@ int __sgx_free_page(struct sgx_epc_page *page)
struct sgx_epc_section *section = sgx_epc_section(page);
int ret;
+ /*
+ * Remove the page from the active list if necessary. If the page
+ * is actively being reclaimed, i.e. RECLAIMABLE is set but the
+ * page isn't on the active list, return -EBUSY as we can't free
+ * the page at this time since it is "owned" by the reclaimer.
+ */
+ spin_lock(&sgx_active_page_list_lock);
+ if (page->desc & SGX_EPC_PAGE_RECLAIMABLE) {
+ if (list_empty(&page->list)) {
+ spin_unlock(&sgx_active_page_list_lock);
+ return -EBUSY;
+ }
+ list_del(&page->list);
+ page->desc &= ~SGX_EPC_PAGE_RECLAIMABLE;
+ }
+ spin_unlock(&sgx_active_page_list_lock);
+
ret = __eremove(sgx_epc_addr(page));
if (ret)
return ret;
@@ -81,15 +264,17 @@ EXPORT_SYMBOL_GPL(__sgx_free_page);
* sgx_free_page - Free an EPC page and WARN on failure
* @page: pointer to a previously allocated EPC page
*
- * EREMOVE an EPC page and insert it back to the list of free pages, and WARN
- * if EREMOVE fails. For use when the call site cannot (or chooses not to)
- * handle failure, i.e. the page is leaked on failure.
+ * EREMOVE an EPC page and insert it back to the list of free pages. If the
+ * page is reclaimable, delete it from the active page list. WARN on any
+ * failure. For use when the call site cannot (or chooses not to) handle
+ * failure, i.e. the page is leaked on failure.
*/
void sgx_free_page(struct sgx_epc_page *page)
{
int ret;
ret = __sgx_free_page(page);
+ WARN(ret < 0, "sgx: cannot free page, reclaim in-progress");
WARN(ret > 0, "sgx: EREMOVE returned %d (0x%x)", ret, ret);
}
EXPORT_SYMBOL_GPL(sgx_free_page);
@@ -142,6 +327,23 @@ int sgx_einit(struct sgx_sigstruct *sigstruct, struct sgx_einittoken *token,
}
EXPORT_SYMBOL(sgx_einit);
+/**
+ * sgx_page_reclaimable - mark a page as reclaimable
+ *
+ * @page: EPC page
+ *
+ * Mark a page as reclaimable and add it to the active page list. Pages
+ * are automatically removed from the active list when freed.
+ */
+void sgx_page_reclaimable(struct sgx_epc_page *page)
+{
+ spin_lock(&sgx_active_page_list_lock);
+ page->desc |= SGX_EPC_PAGE_RECLAIMABLE;
+ list_add_tail(&page->list, &sgx_active_page_list);
+ spin_unlock(&sgx_active_page_list_lock);
+}
+EXPORT_SYMBOL_GPL(sgx_page_reclaimable);
+
static __init void sgx_free_epc_section(struct sgx_epc_section *section)
{
int i;
@@ -190,6 +392,11 @@ static __init void sgx_page_cache_teardown(void)
{
int i;
+ if (ksgxswapd_tsk) {
+ kthread_stop(ksgxswapd_tsk);
+ ksgxswapd_tsk = NULL;
+ }
+
for (i = 0; i < sgx_nr_epc_sections; i++)
sgx_free_epc_section(&sgx_epc_sections[i]);
}
@@ -249,6 +456,7 @@ static __init int sgx_page_cache_init(void)
static __init int sgx_init(void)
{
+ struct task_struct *tsk;
int ret;
if (!boot_cpu_has(X86_FEATURE_SGX))
@@ -258,6 +466,13 @@ static __init int sgx_init(void)
if (ret)
return ret;
+ tsk = kthread_run(ksgxswapd, NULL, "ksgxswapd");
+ if (IS_ERR(tsk)) {
+ sgx_page_cache_teardown();
+ return PTR_ERR(tsk);
+ }
+ ksgxswapd_tsk = tsk;
+
return 0;
}
diff --git a/drivers/platform/x86/intel_sgx/sgx_encl.c b/drivers/platform/x86/intel_sgx/sgx_encl.c
index 1d0a51120e3d..5ef2fa7e92c3 100644
--- a/drivers/platform/x86/intel_sgx/sgx_encl.c
+++ b/drivers/platform/x86/intel_sgx/sgx_encl.c
@@ -191,6 +191,7 @@ static bool sgx_process_add_page_req(struct sgx_add_page_req *req,
encl->secs_child_cnt++;
sgx_set_page_loaded(encl_page, epc_page);
sgx_test_and_clear_young(encl_page);
+ sgx_page_reclaimable(encl_page->epc_page);
return true;
}
@@ -220,7 +221,7 @@ static void sgx_add_page_worker(struct work_struct *work)
if (skip_rest)
goto next;
- epc_page = sgx_alloc_page();
+ epc_page = sgx_alloc_page(req->encl_page, true);
down_read(&encl->mm->mmap_sem);
mutex_lock(&encl->lock);
@@ -467,7 +468,7 @@ int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs)
struct sgx_epc_page *secs_epc;
long ret;
- secs_epc = sgx_alloc_page();
+ secs_epc = sgx_alloc_page(&encl->secs, true);
if (IS_ERR(secs_epc)) {
ret = PTR_ERR(secs_epc);
return ret;
diff --git a/drivers/platform/x86/intel_sgx/sgx_encl_page.c b/drivers/platform/x86/intel_sgx/sgx_encl_page.c
index fc9bea9f4aea..885eea019c86 100644
--- a/drivers/platform/x86/intel_sgx/sgx_encl_page.c
+++ b/drivers/platform/x86/intel_sgx/sgx_encl_page.c
@@ -12,8 +12,7 @@
static inline struct sgx_encl_page *to_encl_page(struct sgx_epc_page *epc_page)
{
- WARN_ON_ONCE(1);
- return NULL;
+ return (struct sgx_encl_page *)epc_page->owner;
}
bool sgx_encl_page_get(struct sgx_epc_page *epc_page)
diff --git a/drivers/platform/x86/intel_sgx/sgx_fault.c b/drivers/platform/x86/intel_sgx/sgx_fault.c
index 61d77e9f8fec..71acb2d3f65c 100644
--- a/drivers/platform/x86/intel_sgx/sgx_fault.c
+++ b/drivers/platform/x86/intel_sgx/sgx_fault.c
@@ -13,7 +13,7 @@ static struct sgx_epc_page *__sgx_load_faulted_page(
struct sgx_epc_page *epc_page;
int ret;
- epc_page = sgx_alloc_page();
+ epc_page = sgx_alloc_page(encl_page, false);
if (IS_ERR(epc_page))
return epc_page;
ret = sgx_encl_load_page(encl_page, epc_page);
@@ -73,6 +73,7 @@ static struct sgx_encl_page *__sgx_fault_page(struct vm_area_struct *vma,
encl->secs_child_cnt++;
sgx_test_and_clear_young(entry);
+ sgx_page_reclaimable(entry->epc_page);
if (do_reserve)
entry->desc |= SGX_ENCL_PAGE_RESERVED;
diff --git a/drivers/platform/x86/intel_sgx/sgx_util.c b/drivers/platform/x86/intel_sgx/sgx_util.c
index eb8072b36a47..1480c4ad0d33 100644
--- a/drivers/platform/x86/intel_sgx/sgx_util.c
+++ b/drivers/platform/x86/intel_sgx/sgx_util.c
@@ -81,7 +81,7 @@ struct sgx_epc_page *sgx_alloc_va_page(void)
struct sgx_epc_page *epc_page;
int ret;
- epc_page = sgx_alloc_page();
+ epc_page = sgx_alloc_page(NULL, true);
if (IS_ERR(epc_page))
return ERR_CAST(epc_page);
--
2.19.1
On Sat, Nov 03, 2018 at 01:11:01AM +0200, Jarkko Sakkinen wrote:
> From: Kai Huang <[email protected]>
>
> X86_FEATURE_SGX reflects whether or not the CPU supports Intel's
> Software Guard eXtensions (SGX).
>
> Signed-off-by: Kai Huang <[email protected]>
This and all the other patches of which you're not the author, need to
have your SOB after the author's SOB.
See Documentation/process/submitting-patches.rst
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
On Sat, Nov 03, 2018 at 12:33:01AM +0100, Borislav Petkov wrote:
> On Sat, Nov 03, 2018 at 01:11:01AM +0200, Jarkko Sakkinen wrote:
> > From: Kai Huang <[email protected]>
> >
> > X86_FEATURE_SGX reflects whether or not the CPU supports Intel's
> > Software Guard eXtensions (SGX).
> >
> > Signed-off-by: Kai Huang <[email protected]>
>
> This and all the other patches of which you're not the author, need to
> have your SOB after the author's SOB.
>
> See Documentation/process/submitting-patches.rst
Right. I know this but forgot to go through this step.
/Jarkko
On 2018-11-02 16:11, Jarkko Sakkinen wrote:
> diff --git a/arch/x86/kernel/cpu/intel_sgx.c b/arch/x86/kernel/cpu/intel_sgx.c
> new file mode 100644
> index 000000000000..b86aa4111592
> --- /dev/null
> +++ b/arch/x86/kernel/cpu/intel_sgx.c
>
> ...
>
> +static __init int sgx_page_cache_init(void)
> +{
> + u32 eax, ebx, ecx, edx, type;
> + u64 pa, size;
> + int ret;
> + int i;
> +
> + BUILD_BUG_ON(SGX_MAX_EPC_SECTIONS > (SGX_EPC_SECTION_MASK + 1));
> +
> + for (i = 0; i < SGX_MAX_EPC_SECTIONS; i++) {
Perhaps print a warning if there are more than SGX_MAX_EPC_SECTIONS
sections reported by CPUID.
> + cpuid_count(SGX_CPUID, i + SGX_CPUID_FIRST_VARIABLE_SUB_LEAF,
> + &eax, &ebx, &ecx, &edx);
> +
> + type = eax & SGX_CPUID_SUB_LEAF_TYPE_MASK;
> + if (type == SGX_CPUID_SUB_LEAF_INVALID)
> + break;
> + if (type != SGX_CPUID_SUB_LEAF_EPC_SECTION) {
> + pr_err_once("sgx: Unknown sub-leaf type: %u\n", type);
> + continue;
> + }
> +
> + pa = sgx_calc_section_metric(eax, ebx);
> + size = sgx_calc_section_metric(ecx, edx);
> + pr_info("sgx: EPC section 0x%llx-0x%llx\n", pa, pa + size - 1);
> +
> + ret = sgx_init_epc_section(pa, size, i, &sgx_epc_sections[i]);
> + if (ret) {
> + sgx_page_cache_teardown();
> + return ret;
> + }
> +
> + sgx_nr_epc_sections++;
> + }
> +
> + if (!sgx_nr_epc_sections) {
> + pr_err("sgx: There are zero EPC sections.\n");
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
--
Jethro Beekman | Fortanix
On Sat, Nov 3, 2018 at 1:16 AM Jarkko Sakkinen
<[email protected]> wrote:
>
> From: Sean Christopherson <[email protected]>
>
> Similar to other large Intel features such as VMX and TXT, SGX must be
> explicitly enabled in IA32_FEATURE_CONTROL MSR to be truly usable.
> Clear all SGX related capabilities if SGX is not fully enabled in
> IA32_FEATURE_CONTROL or if the SGX1 instruction set isn't supported
> (impossible on bare metal, theoretically possible in a VM if the VMM
> is doing something weird).
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> arch/x86/kernel/cpu/intel.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
> index fc3c07fe7df5..9bf8fe2c04ac 100644
> --- a/arch/x86/kernel/cpu/intel.c
> +++ b/arch/x86/kernel/cpu/intel.c
> @@ -596,6 +596,30 @@ static void detect_tme(struct cpuinfo_x86 *c)
> c->x86_phys_bits -= keyid_bits;
> }
>
> +static void detect_sgx(struct cpuinfo_x86 *c)
> +{
> + bool unsupported = false;
> + unsigned long long fc;
> +
> + rdmsrl(MSR_IA32_FEATURE_CONTROL, fc);
> + if (!(fc & FEATURE_CONTROL_LOCKED)) {
> + pr_err_once("sgx: IA32_FEATURE_CONTROL MSR is not locked\n");
> + unsupported = true;
> + } else if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) {
> + pr_err_once("sgx: not enabled in IA32_FEATURE_CONTROL MSR\n");
> + unsupported = true;
> + } else if (!cpu_has(c, X86_FEATURE_SGX1)) {
> + pr_err_once("sgx: SGX1 instruction set not supported\n");
> + unsupported = true;
> + }
If you do
} else {
/* Supported */
return;
}
here, you may get rid of temporary variable.
(Up to you)
> +
> + if (unsupported) {
> + setup_clear_cpu_cap(X86_FEATURE_SGX);
> + setup_clear_cpu_cap(X86_FEATURE_SGX1);
> + setup_clear_cpu_cap(X86_FEATURE_SGX2);
> + }
> +}
> +
> static void init_intel_energy_perf(struct cpuinfo_x86 *c)
> {
> u64 epb;
> @@ -763,6 +787,9 @@ static void init_intel(struct cpuinfo_x86 *c)
> if (cpu_has(c, X86_FEATURE_TME))
> detect_tme(c);
>
> + if (cpu_has(c, X86_FEATURE_SGX))
> + detect_sgx(c);
> +
> init_intel_energy_perf(c);
>
> init_intel_misc_features(c);
> --
> 2.19.1
>
--
With Best Regards,
Andy Shevchenko
On Sat, Nov 3, 2018 at 1:16 AM Jarkko Sakkinen
<[email protected]> wrote:
>
> SGX defines its own CPUID leaf, 0x12, along with a variable number of
> sub-leafs. Sub-leafs 0 and 1 are always available if SGX is supported
> and enumerate various SGX features, e.g. instruction sets and enclave
> capabilities. Sub-leafs 2+ are variable, both in their existence and
> in what they enumerate. Bits 3:0 of EAX report the sub-leaf type,
> with the remaining bits in EAX, EBX, ECX and EDX being type-specific.
> Currently, the only known sub-leaf type enumerates an EPC section. An
> EPC section is simply a range of EPC memory available to software.
> The "list" of varaible SGX sub-leafs is NULL-terminated, i.e. software
> is expected to query CPUID until an invalid sub-leaf is encountered.
> + SGX_CPUID_SUB_LEAF_TYPE_MASK = 0xF,
GENMASK() if it suits here?
P.S. Btw, BIT() and GENMASK() macros are now in a separate header,
i.e. linux/bits.h, perhaps you might need to revisit code to include
it explicitly
--
With Best Regards,
Andy Shevchenko
On Sat, Nov 3, 2018 at 1:17 AM Jarkko Sakkinen
<[email protected]> wrote:
>
> From: Sean Christopherson <[email protected]>
>
> Like SGX itself, SGX Launch Control must be explicitly enabled via a
> flag in IA32_FEATURE_CONTROL. Clear the SGX_LC capability if Launch
> Control is not fully enabled (or obviously if SGX itself is disabled).
>
> Note that clearing X86_FEATURE_SGX_LC creates a bit of a conundrum
> regarding the SGXLEPUBKEYHASH MSRs, as it may be desirable to read the
> MSRs even if they are not writable, e.g. to query the configured key,
> but clearing the capability leaves no breadcrum for discerning whether
> or not the MSRs exist. But, such usage will be rare (KVM is the only
> known case at this time) and not performance critical, so it's not
> unreasonable to require the use of rdmsr_safe(). Clearing the cap bit
> eliminates the need for an additional flag to track whether or not
> Launch Control is truly enabled, which is what we care about the vast
> majority of the time.
> @@ -618,6 +618,8 @@ static void detect_sgx(struct cpuinfo_x86 *c)
> setup_clear_cpu_cap(X86_FEATURE_SGX1);
> setup_clear_cpu_cap(X86_FEATURE_SGX2);
> }
> + if (unsupported || !(fc & FEATURE_CONTROL_SGX_LE_WR))
> + setup_clear_cpu_cap(X86_FEATURE_SGX_LC);
> }
A-ha, I see how you use this variable here (though it's still possible
to get rid of it, choose what is better for readability /
maintenance).
--
With Best Regards,
Andy Shevchenko
On Sat, Nov 3, 2018 at 1:18 AM Jarkko Sakkinen
<[email protected]> wrote:
>
> ENCLS is an umbrella instruction for a variety of cpl0 SGX functions.
> The ENCLS function that is executed is specified in EAX, with each
> function potentially having more leaf-specific operands beyond EAX.
> ENCLS introduces its own (positive value) error codes that (some)
> leafs use to return failure information in EAX. Leafs that return
> an error code also modify RFLAGS. And finally, ENCLS generates
> ENCLS-specific non-fatal #GPs and #PFs, i.e. a bug-free kernel may
> encounter faults on ENCLS that must be handled gracefully.
>
> Because of the complexity involved in encoding ENCLS and handling its
> assortment of failure paths, executing any given leaf is not a simple
> matter of emitting ENCLS.
>
> To enable adding support for ENCLS leafs with minimal fuss, add a
> two-layer macro system along with an encoding scheme to allow wrappers
> to return trap numbers along ENCLS-specific error codes. The bottom
> layer of the macro system splits between the leafs that return an
> error code and those that do not. The second layer generates the
> correct input/output annotations based on the number of operands for
> each leaf function.
> +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
> +/**
I dunno if kernel-doc script still complains about this.
> + * Copyright(c) 2016-18 Intel Corporation.
> + */
--
With Best Regards,
Andy Shevchenko
On Sat, Nov 3, 2018 at 1:17 AM Jarkko Sakkinen
<[email protected]> wrote:
>
> From: Sean Christopherson <[email protected]>
>
> Enumerate Enclave Page Cache (EPC) sections via CPUID and add the data
> structures necessary to track EPC pages so that they can be allocated,
> freed and managed. As a system may have multiple EPC sections, invoke
> CPUID on SGX sub-leafs until an invalid leaf is encountered.
>
> On NUMA systems, a node can have at most one bank. A bank can be at
> most part of two nodes. SGX supports both nodes with a single memory
> controller and also sub-cluster nodes with severals memory controllers
> on a single die.
>
> For simplicity, support a maximum of eight EPC sections. Current
> client hardware supports only a single section, while upcoming server
> hardware will support at most eight sections. Bounding the number of
> sections also allows the section ID to be embedded along with a page's
> offset in a single unsigned long, enabling easy retrieval of both the
> VA and PA for a given page.
> + iounmap(section->va);
> + section->va = ioremap_cache(addr, size);
> + if (!section->va)
> + return -ENOMEM;
I forgot if it's a place in code on which we discussed ioremap() vs.
memremap() call.
And I forgot why the conclusion is to leave ioremap().
Sorry, if I'm mistaken.
--
With Best Regards,
Andy Shevchenko
On Sat, Nov 03, 2018 at 01:11:22AM +0200, Jarkko Sakkinen wrote:
> Documentation of the features of the Software Guard eXtensions used
> by the Linux kernel and basic design choices for the core and driver
> and functionality.
>
> Signed-off-by: Jarkko Sakkinen <[email protected]>
> ---
> Documentation/index.rst | 1 +
> Documentation/x86/intel_sgx.rst | 185 ++++++++++++++++++++++++++++++++
> 2 files changed, 186 insertions(+)
> create mode 100644 Documentation/x86/intel_sgx.rst
>
> diff --git a/Documentation/index.rst b/Documentation/index.rst
> index 5db7e87c7cb1..1cdc139adb40 100644
> --- a/Documentation/index.rst
> +++ b/Documentation/index.rst
> @@ -104,6 +104,7 @@ implementation.
> :maxdepth: 2
>
> sh/index
> + x86/index
It seems there is no Documentation/x86/index.rst, probably you'd want to
create one and link intel_sgx.rst there
>
> Filesystem Documentation
> ------------------------
> diff --git a/Documentation/x86/intel_sgx.rst b/Documentation/x86/intel_sgx.rst
> new file mode 100644
> index 000000000000..f6b7979c41f2
> --- /dev/null
> +++ b/Documentation/x86/intel_sgx.rst
> @@ -0,0 +1,185 @@
> +===================
> +Intel(R) SGX driver
> +===================
> +
> +Introduction
> +============
> +
> +Intel(R) SGX is a set of CPU instructions that can be used by applications to
> +set aside private regions of code and data. The code outside the enclave is
> +disallowed to access the memory inside the enclave by the CPU access control.
> +In a way you can think that SGX provides inverted sandbox. It protects the
> +application from a malicious host.
> +
> +You can tell if your CPU supports SGX by looking into ``/proc/cpuinfo``:
> +
> + ``cat /proc/cpuinfo | grep sgx``
> +
> +Overview of SGX
> +===============
> +
> +SGX has a set of data structures to maintain information about the enclaves and
> +their security properties. BIOS reserves a fixed size region of physical memory
> +for these structures by setting Processor Reserved Memory Range Registers
> +(PRMRR).
> +
> +This memory range is protected from outside access by the CPU and all the data
> +coming in and out of the CPU package is encrypted by a key that is generated for
> +each boot cycle.
> +
> +Enclaves execute in ring-3 in a special enclave submode using pages from the
> +reserved memory range. A fixed logical address range for the enclave is reserved
> +by ENCLS(ECREATE), a leaf instruction used to create enclaves. It is referred in
> +the documentation commonly as the ELRANGE.
> +
> +Every memory access to the ELRANGE is asserted by the CPU. If the CPU is not
> +executing in the enclave mode inside the enclave, #GP is raised. On the other
> +hand enclave code can make memory accesses both inside and outside of the
comma ^
> +ELRANGE.
> +
> +Enclave can only execute code inside the ELRANGE. Instructions that may cause
> +VMEXIT, IO instructions and instructions that require a privilege change are
> +prohibited inside the enclave. Interrupts and exceptions always cause enclave
> +to exit and jump to an address outside the enclave given when the enclave is
> +entered by using the leaf instruction ENCLS(EENTER).
> +
> +Data types
> +----------
> +
> +The protected memory range contains the following data:
> +
> +* **Enclave Page Cache (EPC):** protected pages
> +* **Enclave Page Cache Map (EPCM):** a database that describes the state of the
> + pages and link them to an enclave.
I think it's better to use "definition list" here
http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html#definition-lists
> +EPC has a number of different types of pages:
> +
> +* **SGX Enclave Control Structure (SECS)**: describes the global
> + properties of an enclave.
> +* **Regular (REG):** code and data pages in the ELRANGE.
> +* **Thread Control Structure (TCS):** pages that define entry points inside an
> + enclave. The enclave can only be entered through these entry points and each
> + can host a single hardware thread at a time.
> +* **Version Array (VA)**: 64-bit version numbers for pages that have been
> + swapped outside the enclave. Each page contains 512 version numbers.
ditto
> +Launch control
> +--------------
> +
> +To launch an enclave, two structures must be provided for ENCLS(EINIT):
> +
> +1. **SIGSTRUCT:** signed measurement of the enclave binary.
> +2. **EINITTOKEN:** a cryptographic token CMAC-signed with a AES256-key called
> + *launch key*, which is re-generated for each boot cycle.
ditto
> +The CPU holds a SHA256 hash of a 3072-bit RSA public key inside
> +IA32_SGXLEPUBKEYHASHn MSRs. Enclaves with a SIGSTRUCT that is signed with this
> +key do not require a valid EINITTOKEN and can be authorized with special
> +privileges. One of those privileges is ability to acquire the launch key with
> +ENCLS(EGETKEY).
> +
> +**IA32_FEATURE_CONTROL[17]** is used by the BIOS configure whether
> +IA32_SGXLEPUBKEYHASH MSRs are read-only or read-write before locking the
> +feature control register and handing over control to the operating system.
> +
> +Enclave construction
> +--------------------
> +
> +The construction is started by filling out the SECS that contains enclave
> +address range, privileged attributes and measurement of TCS and REG pages (pages
> +that will be mapped to the address range) among the other things. This structure
> +is passed out to the ENCLS(ECREATE) together with a physical address of a page
> +in EPC that will hold the SECS.
> +
> +The pages are added with ENCLS(EADD) and measured with ENCLS(EEXTEND) i.e.
> +SHA256 hash MRENCLAVE residing in the SECS is extended with the page data.
> +
> +After all of the pages have been added, the enclave is initialized with
> +ENCLS(EINIT). ENCLS(INIT) checks that the SIGSTRUCT is signed with the contained
EINIT?
> +public key. If the given EINITTOKEN has the valid bit set, the CPU checks that
> +the token is valid (CMAC'd with the launch key). If the token is not valid,
> +the CPU will check whether the enclave is signed with a key matching to the
> +IA32_SGXLEPUBKEYHASHn MSRs.
> +
> +Swapping pages
> +--------------
> +
> +Enclave pages can be swapped out with ENCLS(EWB) to the unprotected memory. In
> +addition to the EPC page, ENCLS(EWB) takes in a VA page and address for PCMD
> +structure (Page Crypto MetaData) as input. The VA page will seal a version
> +number for the page. PCMD is 128 byte structure that contains tracking
> +information for the page, most importantly its MAC. With these structures the
> +enclave is sealed and rollback protected while it resides in the unprotected
> +memory.
> +
> +Before the page can be swapped out it must not have any active TLB references.
> +ENCLS(EBLOCK) instruction moves a page to the *blocked* state, which means
> +that no new TLB entries can be created to it by the hardware threads.
> +
> +After this a shootdown sequence is started with ENCLS(ETRACK), which sets an
> +increased counter value to the entering hardware threads. ENCLS(EWB) will
> +return SGX_NOT_TRACKED error while there are still threads with the earlier
> +couner value because that means that there might be hardware thread inside
> +the enclave with TLB entries to pages that are to be swapped.
> +
> +Kernel internals
> +================
> +
> +Requirements
> +------------
> +
> +Because SGX has an ever evolving and expanding feature set, it's possible for
> +a BIOS or VMM to configure a system in such a way that not all CPUs are equal,
> +e.g. where Launch Control is only enabled on a subset of CPUs. Linux does
> +*not* support such a heterogeneous system configuration, nor does it even
> +attempt to play nice in the face of a misconfigured system. With the exception
> +of Launch Control's hash MSRs, which can vary per CPU, Linux assumes that all
> +CPUs have a configuration that is identical to the boot CPU.
> +
> +
> +Roles and responsibilities
> +--------------------------
> +
> +SGX introduces system resources, e.g. EPC memory, that must be accessible to
> +multiple entities, e.g. the native kernel driver (to expose SGX to userspace)
> +and KVM (to expose SGX to VMs), ideally without introducing any dependencies
> +between each SGX entity. To that end, the kernel owns and manages the shared
> +system resources, i.e. the EPC and Launch Control MSRs, and defines functions
> +that provide appropriate access to the shared resources. SGX support for
> +user space and VMs is left to the SGX platform driver and KVM respectively.
> +
> +Launching enclaves
> +------------------
> +
> +The current kernel implementation supports only unlocked MSRs i.e.
> +FEATURE_CONTROL_SGX_LE_WR must be set. The launch is performed by setting the
> +MSRs to the hash of the public key modulus of the enclave signer, which is one
> +f the fields in the SIGSTRUCT.
of
> +
> +EPC management
> +--------------
> +
> +Due to the unique requirements for swapping EPC pages, and because EPC pages
> +(currently) do not have associated page structures, management of the EPC is
> +not handled by the standard Linux swapper. SGX directly handles swapping
> +of EPC pages, including a kthread to initiate reclaim and a rudimentary LRU
> +mechanism. The consumers of EPC pages, e.g. the SGX driver, are required to
> +implement function callbacks that can be invoked by the kernel to age,
> +swap, and/or forcefully reclaim a target EPC page. In effect, the kernel
> +controls what happens and when, while the consumers (driver, KVM, etc..) do
> +the actual work.
> +
> +SGX uapi
> +========
> +
> +.. kernel-doc:: drivers/platform/x86/intel_sgx/sgx_ioctl.c
> + :functions: sgx_ioc_enclave_create
> + sgx_ioc_enclave_add_page
> + sgx_ioc_enclave_init
> +
> +.. kernel-doc:: arch/x86/include/uapi/asm/sgx.h
> +
> +References
> +==========
> +
> +* System Programming Manual: 39.1.4 Intel? SGX Launch Control Configuration
> --
> 2.19.1
>
--
Sincerely yours,
Mike.
On Mon, Nov 05, 2018 at 04:09:33PM +0200, Jarkko Sakkinen wrote:
> On Sat, Nov 03, 2018 at 03:05:39PM +0200, Andy Shevchenko wrote:
> > > +static void detect_sgx(struct cpuinfo_x86 *c)
> > > +{
> > > + bool unsupported = false;
> > > + unsigned long long fc;
> > > +
> > > + rdmsrl(MSR_IA32_FEATURE_CONTROL, fc);
> > > + if (!(fc & FEATURE_CONTROL_LOCKED)) {
> > > + pr_err_once("sgx: IA32_FEATURE_CONTROL MSR is not locked\n");
> > > + unsupported = true;
> > > + } else if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) {
> > > + pr_err_once("sgx: not enabled in IA32_FEATURE_CONTROL MSR\n");
> > > + unsupported = true;
> > > + } else if (!cpu_has(c, X86_FEATURE_SGX1)) {
> > > + pr_err_once("sgx: SGX1 instruction set not supported\n");
> > > + unsupported = true;
> > > + }
> >
> > If you do
> >
> > } else {
> > /* Supported */
> > return;
> > }
>
> Agree. Would this be a more clean flow in the attached patch?
Actually I'll paste the whole function for clarity because it is not too
long:
static void detect_sgx(struct cpuinfo_x86 *c)
{
unsigned long long fc;
rdmsrl(MSR_IA32_FEATURE_CONTROL, fc);
if (!(fc & FEATURE_CONTROL_LOCKED)) {
pr_err_once("sgx: IA32_FEATURE_CONTROL MSR is not locked\n");
goto out_unsupported;
}
if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) {
pr_err_once("sgx: not enabled in IA32_FEATURE_CONTROL MSR\n");
goto out_unsupported;
}
if (!cpu_has(c, X86_FEATURE_SGX1)) {
pr_err_once("sgx: SGX1 instruction set not supported\n");
goto out_unsupported;
}
if (!(fc & FEATURE_CONTROL_SGX_LE_WR)) {
pr_info_once("sgx: launch control MSRs are not writable\n");
goto out_msrs_rdonly;
}
return;
out_unsupported:
setup_clear_cpu_cap(X86_FEATURE_SGX);
setup_clear_cpu_cap(X86_FEATURE_SGX1);
setup_clear_cpu_cap(X86_FEATURE_SGX2);
out_msrs_rdonly:
setup_clear_cpu_cap(X86_FEATURE_SGX_LC);
}
/Jarkko
On Sat, Nov 03, 2018 at 03:05:39PM +0200, Andy Shevchenko wrote:
> > +static void detect_sgx(struct cpuinfo_x86 *c)
> > +{
> > + bool unsupported = false;
> > + unsigned long long fc;
> > +
> > + rdmsrl(MSR_IA32_FEATURE_CONTROL, fc);
> > + if (!(fc & FEATURE_CONTROL_LOCKED)) {
> > + pr_err_once("sgx: IA32_FEATURE_CONTROL MSR is not locked\n");
> > + unsupported = true;
> > + } else if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) {
> > + pr_err_once("sgx: not enabled in IA32_FEATURE_CONTROL MSR\n");
> > + unsupported = true;
> > + } else if (!cpu_has(c, X86_FEATURE_SGX1)) {
> > + pr_err_once("sgx: SGX1 instruction set not supported\n");
> > + unsupported = true;
> > + }
>
> If you do
>
> } else {
> /* Supported */
> return;
> }
Agree. Would this be a more clean flow in the attached patch?
/Jarkko
On Mon, Nov 05, 2018 at 04:09:33PM +0200, Jarkko Sakkinen wrote:
> On Sat, Nov 03, 2018 at 03:05:39PM +0200, Andy Shevchenko wrote:
> Agree. Would this be a more clean flow in the attached patch?
LGTM.
> From 3b863a7db00cefffc15df918a5132c35ea313c27 Mon Sep 17 00:00:00 2001
> From: Jarkko Sakkinen <[email protected]>
> Date: Mon, 5 Nov 2018 16:06:06 +0200
> Subject: [PATCH] x86/cpu/intel: clean up detect_sgx() flow
>
> Signed-off-by: Jarkko Sakkinen <[email protected]>
> ---
> arch/x86/kernel/cpu/intel.c | 32 ++++++++++++++++++++------------
> 1 file changed, 20 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
> index bc52c52f7025..8a20a193d399 100644
> --- a/arch/x86/kernel/cpu/intel.c
> +++ b/arch/x86/kernel/cpu/intel.c
> @@ -598,28 +598,36 @@ static void detect_tme(struct cpuinfo_x86 *c)
>
> static void detect_sgx(struct cpuinfo_x86 *c)
> {
> - bool unsupported = false;
> unsigned long long fc;
>
> rdmsrl(MSR_IA32_FEATURE_CONTROL, fc);
> if (!(fc & FEATURE_CONTROL_LOCKED)) {
> pr_err_once("sgx: IA32_FEATURE_CONTROL MSR is not locked\n");
> - unsupported = true;
> - } else if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) {
> + goto out_unsupported;
> + }
> +
> + if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) {
> pr_err_once("sgx: not enabled in IA32_FEATURE_CONTROL MSR\n");
> - unsupported = true;
> - } else if (!cpu_has(c, X86_FEATURE_SGX1)) {
> + goto out_unsupported;
> + }
> +
> + if (!cpu_has(c, X86_FEATURE_SGX1)) {
> pr_err_once("sgx: SGX1 instruction set not supported\n");
> - unsupported = true;
> + goto out_unsupported;
> }
>
> - if (unsupported) {
> - setup_clear_cpu_cap(X86_FEATURE_SGX);
> - setup_clear_cpu_cap(X86_FEATURE_SGX1);
> - setup_clear_cpu_cap(X86_FEATURE_SGX2);
> + if (!(fc & FEATURE_CONTROL_SGX_LE_WR)) {
> + pr_info_once("sgx: launch control MSRs are not writable\n");
> + goto out_msrs_rdonly;
> }
> - if (unsupported || !(fc & FEATURE_CONTROL_SGX_LE_WR))
> - setup_clear_cpu_cap(X86_FEATURE_SGX_LC);
> +
> + return;
> +out_unsupported:
> + setup_clear_cpu_cap(X86_FEATURE_SGX);
> + setup_clear_cpu_cap(X86_FEATURE_SGX1);
> + setup_clear_cpu_cap(X86_FEATURE_SGX2);
> +out_msrs_rdonly:
> + setup_clear_cpu_cap(X86_FEATURE_SGX_LC);
> }
>
> static void init_intel_energy_perf(struct cpuinfo_x86 *c)
> --
> 2.19.1
>
--
With Best Regards,
Andy Shevchenko
On Sat, Nov 03, 2018 at 03:11:39PM +0200, Andy Shevchenko wrote:
> On Sat, Nov 3, 2018 at 1:16 AM Jarkko Sakkinen
> <[email protected]> wrote:
> >
> > SGX defines its own CPUID leaf, 0x12, along with a variable number of
> > sub-leafs. Sub-leafs 0 and 1 are always available if SGX is supported
> > and enumerate various SGX features, e.g. instruction sets and enclave
> > capabilities. Sub-leafs 2+ are variable, both in their existence and
> > in what they enumerate. Bits 3:0 of EAX report the sub-leaf type,
> > with the remaining bits in EAX, EBX, ECX and EDX being type-specific.
> > Currently, the only known sub-leaf type enumerates an EPC section. An
> > EPC section is simply a range of EPC memory available to software.
> > The "list" of varaible SGX sub-leafs is NULL-terminated, i.e. software
> > is expected to query CPUID until an invalid sub-leaf is encountered.
>
> > + SGX_CPUID_SUB_LEAF_TYPE_MASK = 0xF,
>
> GENMASK() if it suits here?
>
> P.S. Btw, BIT() and GENMASK() macros are now in a separate header,
> i.e. linux/bits.h, perhaps you might need to revisit code to include
> it explicitly
Agreed. I would also think that is should be renamed simply as
SGX_CPUID_SUBLEAF_MASK.
/Jarkko
On Sat, Nov 03, 2018 at 03:15:15PM +0200, Andy Shevchenko wrote:
> > @@ -618,6 +618,8 @@ static void detect_sgx(struct cpuinfo_x86 *c)
> > setup_clear_cpu_cap(X86_FEATURE_SGX1);
> > setup_clear_cpu_cap(X86_FEATURE_SGX2);
> > }
> > + if (unsupported || !(fc & FEATURE_CONTROL_SGX_LE_WR))
> > + setup_clear_cpu_cap(X86_FEATURE_SGX_LC);
> > }
>
> A-ha, I see how you use this variable here (though it's still possible
> to get rid of it, choose what is better for readability /
> maintenance).
I would propose to squash this one to the earlier commit and refactor
it in a way that I proposed. Having this part as a separate commit in
my opinion is a bit confusing.
/Jarkko
On Sat, Nov 03, 2018 at 03:17:35PM +0200, Andy Shevchenko wrote:
> On Sat, Nov 3, 2018 at 1:18 AM Jarkko Sakkinen
> <[email protected]> wrote:
> >
> > ENCLS is an umbrella instruction for a variety of cpl0 SGX functions.
> > The ENCLS function that is executed is specified in EAX, with each
> > function potentially having more leaf-specific operands beyond EAX.
> > ENCLS introduces its own (positive value) error codes that (some)
> > leafs use to return failure information in EAX. Leafs that return
> > an error code also modify RFLAGS. And finally, ENCLS generates
> > ENCLS-specific non-fatal #GPs and #PFs, i.e. a bug-free kernel may
> > encounter faults on ENCLS that must be handled gracefully.
> >
> > Because of the complexity involved in encoding ENCLS and handling its
> > assortment of failure paths, executing any given leaf is not a simple
> > matter of emitting ENCLS.
> >
> > To enable adding support for ENCLS leafs with minimal fuss, add a
> > two-layer macro system along with an encoding scheme to allow wrappers
> > to return trap numbers along ENCLS-specific error codes. The bottom
> > layer of the macro system splits between the leafs that return an
> > error code and those that do not. The second layer generates the
> > correct input/output annotations based on the number of operands for
> > each leaf function.
>
> > +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
>
> > +/**
>
> I dunno if kernel-doc script still complains about this.
Is there a way to ask for make htmldocs to do only a subset of docs?
Still kind of trying to figure out what would be a good flow for
working with Sphinx.
/Jarkko
On Sat, Nov 03, 2018 at 01:07:27AM +0000, Jethro Beekman wrote:
> > + for (i = 0; i < SGX_MAX_EPC_SECTIONS; i++) {
>
> Perhaps print a warning if there are more than SGX_MAX_EPC_SECTIONS sections
> reported by CPUID.
Makes sense. I'll add it.
/Jarkko
On Sat, Nov 03, 2018 at 03:22:34PM +0200, Andy Shevchenko wrote:
> On Sat, Nov 3, 2018 at 1:17 AM Jarkko Sakkinen
> <[email protected]> wrote:
> >
> > From: Sean Christopherson <[email protected]>
> >
> > Enumerate Enclave Page Cache (EPC) sections via CPUID and add the data
> > structures necessary to track EPC pages so that they can be allocated,
> > freed and managed. As a system may have multiple EPC sections, invoke
> > CPUID on SGX sub-leafs until an invalid leaf is encountered.
> >
> > On NUMA systems, a node can have at most one bank. A bank can be at
> > most part of two nodes. SGX supports both nodes with a single memory
> > controller and also sub-cluster nodes with severals memory controllers
> > on a single die.
> >
> > For simplicity, support a maximum of eight EPC sections. Current
> > client hardware supports only a single section, while upcoming server
> > hardware will support at most eight sections. Bounding the number of
> > sections also allows the section ID to be embedded along with a page's
> > offset in a single unsigned long, enabling easy retrieval of both the
> > VA and PA for a given page.
>
> > + iounmap(section->va);
>
> > + section->va = ioremap_cache(addr, size);
> > + if (!section->va)
> > + return -ENOMEM;
>
> I forgot if it's a place in code on which we discussed ioremap() vs.
> memremap() call.
> And I forgot why the conclusion is to leave ioremap().
>
> Sorry, if I'm mistaken.
Thanks for pointing this out. It very well might I have either
1. forgotten to do the switch.
2. had some open about it that I forgot to ask.
Anyway, I'll check this and at minimum document the reason to the
change log if there is one to keep the ioremap().
/Jarkko
On Sun, Nov 04, 2018 at 10:15:13AM +0200, Mike Rapoport wrote:
> On Sat, Nov 03, 2018 at 01:11:22AM +0200, Jarkko Sakkinen wrote:
> > Documentation of the features of the Software Guard eXtensions used
> > by the Linux kernel and basic design choices for the core and driver
> > and functionality.
> >
> > Signed-off-by: Jarkko Sakkinen <[email protected]>
> > ---
> > Documentation/index.rst | 1 +
> > Documentation/x86/intel_sgx.rst | 185 ++++++++++++++++++++++++++++++++
> > 2 files changed, 186 insertions(+)
> > create mode 100644 Documentation/x86/intel_sgx.rst
> >
> > diff --git a/Documentation/index.rst b/Documentation/index.rst
> > index 5db7e87c7cb1..1cdc139adb40 100644
> > --- a/Documentation/index.rst
> > +++ b/Documentation/index.rst
> > @@ -104,6 +104,7 @@ implementation.
> > :maxdepth: 2
> >
> > sh/index
> > + x86/index
>
> It seems there is no Documentation/x86/index.rst, probably you'd want to
> create one and link intel_sgx.rst there
Thanks I'll update this!
>
> >
> > Filesystem Documentation
> > ------------------------
> > diff --git a/Documentation/x86/intel_sgx.rst b/Documentation/x86/intel_sgx.rst
> > new file mode 100644
> > index 000000000000..f6b7979c41f2
> > --- /dev/null
> > +++ b/Documentation/x86/intel_sgx.rst
> > @@ -0,0 +1,185 @@
> > +===================
> > +Intel(R) SGX driver
> > +===================
> > +
> > +Introduction
> > +============
> > +
> > +Intel(R) SGX is a set of CPU instructions that can be used by applications to
> > +set aside private regions of code and data. The code outside the enclave is
> > +disallowed to access the memory inside the enclave by the CPU access control.
> > +In a way you can think that SGX provides inverted sandbox. It protects the
> > +application from a malicious host.
> > +
> > +You can tell if your CPU supports SGX by looking into ``/proc/cpuinfo``:
> > +
> > + ``cat /proc/cpuinfo | grep sgx``
> > +
> > +Overview of SGX
> > +===============
> > +
> > +SGX has a set of data structures to maintain information about the enclaves and
> > +their security properties. BIOS reserves a fixed size region of physical memory
> > +for these structures by setting Processor Reserved Memory Range Registers
> > +(PRMRR).
> > +
> > +This memory range is protected from outside access by the CPU and all the data
> > +coming in and out of the CPU package is encrypted by a key that is generated for
> > +each boot cycle.
> > +
> > +Enclaves execute in ring-3 in a special enclave submode using pages from the
> > +reserved memory range. A fixed logical address range for the enclave is reserved
> > +by ENCLS(ECREATE), a leaf instruction used to create enclaves. It is referred in
> > +the documentation commonly as the ELRANGE.
> > +
> > +Every memory access to the ELRANGE is asserted by the CPU. If the CPU is not
> > +executing in the enclave mode inside the enclave, #GP is raised. On the other
> > +hand enclave code can make memory accesses both inside and outside of the
>
> comma ^
>
> > +ELRANGE.
> > +
> > +Enclave can only execute code inside the ELRANGE. Instructions that may cause
> > +VMEXIT, IO instructions and instructions that require a privilege change are
> > +prohibited inside the enclave. Interrupts and exceptions always cause enclave
> > +to exit and jump to an address outside the enclave given when the enclave is
> > +entered by using the leaf instruction ENCLS(EENTER).
> > +
> > +Data types
> > +----------
> > +
> > +The protected memory range contains the following data:
> > +
> > +* **Enclave Page Cache (EPC):** protected pages
> > +* **Enclave Page Cache Map (EPCM):** a database that describes the state of the
> > + pages and link them to an enclave.
>
> I think it's better to use "definition list" here
>
> http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html#definition-lists
Ack.
>
> > +EPC has a number of different types of pages:
> > +
> > +* **SGX Enclave Control Structure (SECS)**: describes the global
> > + properties of an enclave.
> > +* **Regular (REG):** code and data pages in the ELRANGE.
> > +* **Thread Control Structure (TCS):** pages that define entry points inside an
> > + enclave. The enclave can only be entered through these entry points and each
> > + can host a single hardware thread at a time.
> > +* **Version Array (VA)**: 64-bit version numbers for pages that have been
> > + swapped outside the enclave. Each page contains 512 version numbers.
>
> ditto
>
> > +Launch control
> > +--------------
> > +
> > +To launch an enclave, two structures must be provided for ENCLS(EINIT):
> > +
> > +1. **SIGSTRUCT:** signed measurement of the enclave binary.
> > +2. **EINITTOKEN:** a cryptographic token CMAC-signed with a AES256-key called
> > + *launch key*, which is re-generated for each boot cycle.
>
> ditto
>
> > +The CPU holds a SHA256 hash of a 3072-bit RSA public key inside
> > +IA32_SGXLEPUBKEYHASHn MSRs. Enclaves with a SIGSTRUCT that is signed with this
> > +key do not require a valid EINITTOKEN and can be authorized with special
> > +privileges. One of those privileges is ability to acquire the launch key with
> > +ENCLS(EGETKEY).
> > +
> > +**IA32_FEATURE_CONTROL[17]** is used by the BIOS configure whether
> > +IA32_SGXLEPUBKEYHASH MSRs are read-only or read-write before locking the
> > +feature control register and handing over control to the operating system.
> > +
> > +Enclave construction
> > +--------------------
> > +
> > +The construction is started by filling out the SECS that contains enclave
> > +address range, privileged attributes and measurement of TCS and REG pages (pages
> > +that will be mapped to the address range) among the other things. This structure
> > +is passed out to the ENCLS(ECREATE) together with a physical address of a page
> > +in EPC that will hold the SECS.
> > +
> > +The pages are added with ENCLS(EADD) and measured with ENCLS(EEXTEND) i.e.
> > +SHA256 hash MRENCLAVE residing in the SECS is extended with the page data.
> > +
> > +After all of the pages have been added, the enclave is initialized with
> > +ENCLS(EINIT). ENCLS(INIT) checks that the SIGSTRUCT is signed with the contained
>
> EINIT?
Yep.
>
> > +public key. If the given EINITTOKEN has the valid bit set, the CPU checks that
> > +the token is valid (CMAC'd with the launch key). If the token is not valid,
> > +the CPU will check whether the enclave is signed with a key matching to the
> > +IA32_SGXLEPUBKEYHASHn MSRs.
> > +
> > +Swapping pages
> > +--------------
> > +
> > +Enclave pages can be swapped out with ENCLS(EWB) to the unprotected memory. In
> > +addition to the EPC page, ENCLS(EWB) takes in a VA page and address for PCMD
> > +structure (Page Crypto MetaData) as input. The VA page will seal a version
> > +number for the page. PCMD is 128 byte structure that contains tracking
> > +information for the page, most importantly its MAC. With these structures the
> > +enclave is sealed and rollback protected while it resides in the unprotected
> > +memory.
> > +
> > +Before the page can be swapped out it must not have any active TLB references.
> > +ENCLS(EBLOCK) instruction moves a page to the *blocked* state, which means
> > +that no new TLB entries can be created to it by the hardware threads.
> > +
> > +After this a shootdown sequence is started with ENCLS(ETRACK), which sets an
> > +increased counter value to the entering hardware threads. ENCLS(EWB) will
> > +return SGX_NOT_TRACKED error while there are still threads with the earlier
> > +couner value because that means that there might be hardware thread inside
> > +the enclave with TLB entries to pages that are to be swapped.
> > +
> > +Kernel internals
> > +================
> > +
> > +Requirements
> > +------------
> > +
> > +Because SGX has an ever evolving and expanding feature set, it's possible for
> > +a BIOS or VMM to configure a system in such a way that not all CPUs are equal,
> > +e.g. where Launch Control is only enabled on a subset of CPUs. Linux does
> > +*not* support such a heterogeneous system configuration, nor does it even
> > +attempt to play nice in the face of a misconfigured system. With the exception
> > +of Launch Control's hash MSRs, which can vary per CPU, Linux assumes that all
> > +CPUs have a configuration that is identical to the boot CPU.
> > +
> > +
> > +Roles and responsibilities
> > +--------------------------
> > +
> > +SGX introduces system resources, e.g. EPC memory, that must be accessible to
> > +multiple entities, e.g. the native kernel driver (to expose SGX to userspace)
> > +and KVM (to expose SGX to VMs), ideally without introducing any dependencies
> > +between each SGX entity. To that end, the kernel owns and manages the shared
> > +system resources, i.e. the EPC and Launch Control MSRs, and defines functions
> > +that provide appropriate access to the shared resources. SGX support for
> > +user space and VMs is left to the SGX platform driver and KVM respectively.
> > +
> > +Launching enclaves
> > +------------------
> > +
> > +The current kernel implementation supports only unlocked MSRs i.e.
> > +FEATURE_CONTROL_SGX_LE_WR must be set. The launch is performed by setting the
> > +MSRs to the hash of the public key modulus of the enclave signer, which is one
> > +f the fields in the SIGSTRUCT.
>
> of
>
> > +
> > +EPC management
> > +--------------
> > +
> > +Due to the unique requirements for swapping EPC pages, and because EPC pages
> > +(currently) do not have associated page structures, management of the EPC is
> > +not handled by the standard Linux swapper. SGX directly handles swapping
> > +of EPC pages, including a kthread to initiate reclaim and a rudimentary LRU
> > +mechanism. The consumers of EPC pages, e.g. the SGX driver, are required to
> > +implement function callbacks that can be invoked by the kernel to age,
> > +swap, and/or forcefully reclaim a target EPC page. In effect, the kernel
> > +controls what happens and when, while the consumers (driver, KVM, etc..) do
> > +the actual work.
> > +
> > +SGX uapi
> > +========
> > +
> > +.. kernel-doc:: drivers/platform/x86/intel_sgx/sgx_ioctl.c
> > + :functions: sgx_ioc_enclave_create
> > + sgx_ioc_enclave_add_page
> > + sgx_ioc_enclave_init
> > +
> > +.. kernel-doc:: arch/x86/include/uapi/asm/sgx.h
> > +
> > +References
> > +==========
> > +
> > +* System Programming Manual: 39.1.4 Intel? SGX Launch Control Configuration
> > --
> > 2.19.1
> >
>
> --
> Sincerely yours,
> Mike.
>
Thank for your remarks!
/Jarkko
On 11/2/18 4:11 PM, Jarkko Sakkinen wrote:
> Documentation/index.rst | 1 +
> Documentation/x86/intel_sgx.rst | 185 ++++++++++++++++++++++++++++++++
> 2 files changed, 186 insertions(+)
> create mode 100644 Documentation/x86/intel_sgx.rst
This patch set establishes an ABI. It basically sets in stone a bunch
of behaviors that the enclave, the kernel, and the out-of-enclave code
must follow.
There are a bunch of things that the enclave can do to %rsp or %rip, for
instance, that it is capable and/or permitted to do.
The ABI seems entirely undocumented and rather lightly designed, which
seems like something we should fix before this is merged.
Also, for a feature as massive and complicated as this one, it seems
irresponsible to not have a selftest. Is that not feasible for some reason?
On Mon, Nov 5, 2018 at 7:30 PM Jarkko Sakkinen
<[email protected]> wrote:
>
> On Sat, Nov 03, 2018 at 03:17:35PM +0200, Andy Shevchenko wrote:
> > On Sat, Nov 3, 2018 at 1:18 AM Jarkko Sakkinen
> > <[email protected]> wrote:
> > >
> > > ENCLS is an umbrella instruction for a variety of cpl0 SGX functions.
> > > The ENCLS function that is executed is specified in EAX, with each
> > > function potentially having more leaf-specific operands beyond EAX.
> > > ENCLS introduces its own (positive value) error codes that (some)
> > > leafs use to return failure information in EAX. Leafs that return
> > > an error code also modify RFLAGS. And finally, ENCLS generates
> > > ENCLS-specific non-fatal #GPs and #PFs, i.e. a bug-free kernel may
> > > encounter faults on ENCLS that must be handled gracefully.
> > >
> > > Because of the complexity involved in encoding ENCLS and handling its
> > > assortment of failure paths, executing any given leaf is not a simple
> > > matter of emitting ENCLS.
> > >
> > > To enable adding support for ENCLS leafs with minimal fuss, add a
> > > two-layer macro system along with an encoding scheme to allow wrappers
> > > to return trap numbers along ENCLS-specific error codes. The bottom
> > > layer of the macro system splits between the leafs that return an
> > > error code and those that do not. The second layer generates the
> > > correct input/output annotations based on the number of operands for
> > > each leaf function.
> >
> > > +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
> >
> > > +/**
> >
> > I dunno if kernel-doc script still complains about this.
>
> Is there a way to ask for make htmldocs to do only a subset of docs?
> Still kind of trying to figure out what would be a good flow for
> working with Sphinx.
What I'm telling here is about Copyright notice, which in my
understanding is not a part of kernel-doc formatting. Though I might
be mistaken.
I remember some USB code has that and I saw a warning.
--
With Best Regards,
Andy Shevchenko
On Mon, Nov 05, 2018 at 12:27:11PM -0800, Dave Hansen wrote:
> The ABI seems entirely undocumented and rather lightly designed, which
> seems like something we should fix before this is merged.
ABI is documented in arch/x86/include/uapi/asm/sgx.h that from which the
documentation is included to intel_sgx.rst. I'm not saying that there is
no space refine it but it is neither undocumented.
> Also, for a feature as massive and complicated as this one, it seems
> irresponsible to not have a selftest. Is that not feasible for some reason?
I do have the in-kernel launch enclave stuff backed up here:
https://github.com/jsakkine-intel/sgx-le-host
https://github.com/jsakkine-intel/sgx-le
This is about as simple as it gets without any type of run-time.
/Jarkko
On Tue, Nov 06, 2018 at 07:49:11AM +0200, Jarkko Sakkinen wrote:
> On Mon, Nov 05, 2018 at 12:27:11PM -0800, Dave Hansen wrote:
> > The ABI seems entirely undocumented and rather lightly designed, which
> > seems like something we should fix before this is merged.
>
> ABI is documented in arch/x86/include/uapi/asm/sgx.h that from which the
> documentation is included to intel_sgx.rst. I'm not saying that there is
> no space refine it but it is neither undocumented.
>
> > Also, for a feature as massive and complicated as this one, it seems
> > irresponsible to not have a selftest. Is that not feasible for some reason?
>
> I do have the in-kernel launch enclave stuff backed up here:
>
> https://github.com/jsakkine-intel/sgx-le-host
> https://github.com/jsakkine-intel/sgx-le
>
> This is about as simple as it gets without any type of run-time.
Of course the enclave could be simplified considerably since now it has
full code for EINITTOKEN generation, which is probably an overkill for a
selftest.
It could be simple as just enter and return to and from enclave or
something in-between in terms of complexity.
Even for the simplest enclave you need a signing tool (see sgxsign.c in
my sgx-le repository), a custom linker script and a sophisticated
makefile.
/Jarkko
On Mon, Nov 05, 2018 at 12:27:11PM -0800, Dave Hansen wrote:
> This patch set establishes an ABI. It basically sets in stone a bunch
> of behaviors that the enclave, the kernel, and the out-of-enclave code
> must follow.
>
> There are a bunch of things that the enclave can do to %rsp or %rip, for
> instance, that it is capable and/or permitted to do.
Just want to ask a follow-up from this so that I understand you better.
Now we are talking abou ioctl API, right? I'm not exactly sure how
EENTER/EEXIT/ERESUME behavior connects to that. I understand the tail
of your message but this paragraph left me a bit puzzled...
/Jarkko
On Mon, Nov 05, 2018 at 10:39:46PM +0200, Andy Shevchenko wrote:
> On Mon, Nov 5, 2018 at 7:30 PM Jarkko Sakkinen
> <[email protected]> wrote:
> >
> > On Sat, Nov 03, 2018 at 03:17:35PM +0200, Andy Shevchenko wrote:
> > > On Sat, Nov 3, 2018 at 1:18 AM Jarkko Sakkinen
> > > <[email protected]> wrote:
> > > >
> > > > ENCLS is an umbrella instruction for a variety of cpl0 SGX functions.
> > > > The ENCLS function that is executed is specified in EAX, with each
> > > > function potentially having more leaf-specific operands beyond EAX.
> > > > ENCLS introduces its own (positive value) error codes that (some)
> > > > leafs use to return failure information in EAX. Leafs that return
> > > > an error code also modify RFLAGS. And finally, ENCLS generates
> > > > ENCLS-specific non-fatal #GPs and #PFs, i.e. a bug-free kernel may
> > > > encounter faults on ENCLS that must be handled gracefully.
> > > >
> > > > Because of the complexity involved in encoding ENCLS and handling its
> > > > assortment of failure paths, executing any given leaf is not a simple
> > > > matter of emitting ENCLS.
> > > >
> > > > To enable adding support for ENCLS leafs with minimal fuss, add a
> > > > two-layer macro system along with an encoding scheme to allow wrappers
> > > > to return trap numbers along ENCLS-specific error codes. The bottom
> > > > layer of the macro system splits between the leafs that return an
> > > > error code and those that do not. The second layer generates the
> > > > correct input/output annotations based on the number of operands for
> > > > each leaf function.
> > >
> > > > +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
> > >
> > > > +/**
> > >
> > > I dunno if kernel-doc script still complains about this.
> >
> > Is there a way to ask for make htmldocs to do only a subset of docs?
> > Still kind of trying to figure out what would be a good flow for
> > working with Sphinx.
>
> What I'm telling here is about Copyright notice, which in my
> understanding is not a part of kernel-doc formatting. Though I might
> be mistaken.
> I remember some USB code has that and I saw a warning.
>
> --
> With Best Regards,
> Andy Shevchenko
I'll remove it because I don't find it in other headers under arch/x86.
/Jarkko
On Sat, Nov 03, 2018 at 03:22:34PM +0200, Andy Shevchenko wrote:
> On Sat, Nov 3, 2018 at 1:17 AM Jarkko Sakkinen
> <[email protected]> wrote:
> >
> > From: Sean Christopherson <[email protected]>
> >
> > Enumerate Enclave Page Cache (EPC) sections via CPUID and add the data
> > structures necessary to track EPC pages so that they can be allocated,
> > freed and managed. As a system may have multiple EPC sections, invoke
> > CPUID on SGX sub-leafs until an invalid leaf is encountered.
> >
> > On NUMA systems, a node can have at most one bank. A bank can be at
> > most part of two nodes. SGX supports both nodes with a single memory
> > controller and also sub-cluster nodes with severals memory controllers
> > on a single die.
> >
> > For simplicity, support a maximum of eight EPC sections. Current
> > client hardware supports only a single section, while upcoming server
> > hardware will support at most eight sections. Bounding the number of
> > sections also allows the section ID to be embedded along with a page's
> > offset in a single unsigned long, enabling easy retrieval of both the
> > VA and PA for a given page.
>
> > + iounmap(section->va);
>
> > + section->va = ioremap_cache(addr, size);
> > + if (!section->va)
> > + return -ENOMEM;
>
> I forgot if it's a place in code on which we discussed ioremap() vs.
> memremap() call.
> And I forgot why the conclusion is to leave ioremap().
>
> Sorry, if I'm mistaken.
As far as I can tell you are not mistaken. It happened that in the patch
set version that you gave this comment I first the fixed missing __iomem
annotations because I like to do other changes on top of code that has
no known regressions. Then I guess I simply forgot to replace it with
memremap(). I will do it for the next version.
/Jarkko
On 11/5/18 9:49 PM, Jarkko Sakkinen wrote:
> On Mon, Nov 05, 2018 at 12:27:11PM -0800, Dave Hansen wrote:
>> The ABI seems entirely undocumented and rather lightly designed, which
>> seems like something we should fix before this is merged.
>
> ABI is documented in arch/x86/include/uapi/asm/sgx.h that from which the
> documentation is included to intel_sgx.rst. I'm not saying that there is
> no space refine it but it is neither undocumented.
I specifically mean the instruction flow around asynchronous exits or
explicit enclave exit calls via EEXIT. Signals are part of the ABI but
go unmentioned in the documentation.
It's also worth noting that EENTER *can* act (from the kernel's
perspective) like an instruction that both jumps and sets a bunch of
registers (including %rsp). It's certainly abnormal in that regard.
In fact, in the docs:
> +Enclave can only execute code inside the ELRANGE. Instructions that may cause
> +VMEXIT, IO instructions and instructions that require a privilege change are
> +prohibited inside the enclave. Interrupts and exceptions always cause enclave
> +to exit and jump to an address outside the enclave given when the enclave is
> +entered by using the leaf instruction ENCLS(EENTER).
it's probably a really good idea to explain that the address outside of
the enclave is enclave-provided, and is not, for instance, just the next
instruction after EENTER.
>> Also, for a feature as massive and complicated as this one, it seems
>> irresponsible to not have a selftest. Is that not feasible for some reason?
>
> I do have the in-kernel launch enclave stuff backed up here:
>
> https://github.com/jsakkine-intel/sgx-le-host
> https://github.com/jsakkine-intel/sgx-le
>
> This is about as simple as it gets without any type of run-time.
Does this code run when I type "make kselftest"? If not, I think we
should rectify that.
On Tue, Nov 06, 2018 at 08:45:37AM -0800, Dave Hansen wrote:
> On 11/5/18 9:49 PM, Jarkko Sakkinen wrote:
> > On Mon, Nov 05, 2018 at 12:27:11PM -0800, Dave Hansen wrote:
> >> The ABI seems entirely undocumented and rather lightly designed, which
> >> seems like something we should fix before this is merged.
> >
> > ABI is documented in arch/x86/include/uapi/asm/sgx.h that from which the
> > documentation is included to intel_sgx.rst. I'm not saying that there is
> > no space refine it but it is neither undocumented.
>
> I specifically mean the instruction flow around asynchronous exits or
> explicit enclave exit calls via EEXIT. Signals are part of the ABI but
> go unmentioned in the documentation.
Ok, thanks for clarification. We will document it.
>
> It's also worth noting that EENTER *can* act (from the kernel's
> perspective) like an instruction that both jumps and sets a bunch of
> registers (including %rsp). It's certainly abnormal in that regard.
Agreed.
> In fact, in the docs:
>
> > +Enclave can only execute code inside the ELRANGE. Instructions that may cause
> > +VMEXIT, IO instructions and instructions that require a privilege change are
> > +prohibited inside the enclave. Interrupts and exceptions always cause enclave
> > +to exit and jump to an address outside the enclave given when the enclave is
> > +entered by using the leaf instruction ENCLS(EENTER).
>
> it's probably a really good idea to explain that the address outside of
> the enclave is enclave-provided, and is not, for instance, just the next
> instruction after EENTER.
>
> >> Also, for a feature as massive and complicated as this one, it seems
> >> irresponsible to not have a selftest. Is that not feasible for some reason?
> >
> > I do have the in-kernel launch enclave stuff backed up here:
> >
> > https://github.com/jsakkine-intel/sgx-le-host
> > https://github.com/jsakkine-intel/sgx-le
> >
> > This is about as simple as it gets without any type of run-time.
>
> Does this code run when I type "make kselftest"? If not, I think we
> should rectify that.
No, it doesn't. It is just my backup for the non-SDK user space code
that I've made that I will use to fork my user space SGX projects in
the future.
I can work-out a selftest (and provide a new patch in the series) but
I'm still wondering what the enclave should do. I would suggest that
we start with an enclave that does just EEXIT and nothing else.
/Jarkko
On 11/7/18 8:30 AM, Jarkko Sakkinen wrote:
>> Does this code run when I type "make kselftest"? If not, I think we
>> should rectify that.
> No, it doesn't. It is just my backup for the non-SDK user space code
> that I've made that I will use to fork my user space SGX projects in
> the future.
>
> I can work-out a selftest (and provide a new patch in the series) but
> I'm still wondering what the enclave should do. I would suggest that
> we start with an enclave that does just EEXIT and nothing else.
Yeah, that's a start. But, a good selftest would include things like
faults and error conditions.
On Wed, Nov 07, 2018 at 09:09:37AM -0800, Dave Hansen wrote:
> On 11/7/18 8:30 AM, Jarkko Sakkinen wrote:
> >> Does this code run when I type "make kselftest"? If not, I think we
> >> should rectify that.
> > No, it doesn't. It is just my backup for the non-SDK user space code
> > that I've made that I will use to fork my user space SGX projects in
> > the future.
> >
> > I can work-out a selftest (and provide a new patch in the series) but
> > I'm still wondering what the enclave should do. I would suggest that
> > we start with an enclave that does just EEXIT and nothing else.
>
> Yeah, that's a start. But, a good selftest would include things like
> faults and error conditions.
Great. We can add more entry points to the enclave for different tests
but I'll start with a bare minimum. And yeah but ever goes into next
version I'll document the fault handling.
/Jarkko
On Thu, Nov 08, 2018 at 04:39:42PM +0200, Jarkko Sakkinen wrote:
> On Wed, Nov 07, 2018 at 09:09:37AM -0800, Dave Hansen wrote:
> > On 11/7/18 8:30 AM, Jarkko Sakkinen wrote:
> > >> Does this code run when I type "make kselftest"? If not, I think we
> > >> should rectify that.
> > > No, it doesn't. It is just my backup for the non-SDK user space code
> > > that I've made that I will use to fork my user space SGX projects in
> > > the future.
> > >
> > > I can work-out a selftest (and provide a new patch in the series) but
> > > I'm still wondering what the enclave should do. I would suggest that
> > > we start with an enclave that does just EEXIT and nothing else.
> >
> > Yeah, that's a start. But, a good selftest would include things like
> > faults and error conditions.
>
> Great. We can add more entry points to the enclave for different tests
> but I'll start with a bare minimum. And yeah but ever goes into next
> version I'll document the fault handling.
For the v17 I'll add exactly two test cases:
1. EENTER/EEXIT
2. EENTER/exception
So that it will easier to evaluate and demonstrate exception handling.
/Jarkko
On Thu, Nov 08, 2018 at 09:20:40PM +0200, Jarkko Sakkinen wrote:
> On Thu, Nov 08, 2018 at 04:39:42PM +0200, Jarkko Sakkinen wrote:
> > On Wed, Nov 07, 2018 at 09:09:37AM -0800, Dave Hansen wrote:
> > > On 11/7/18 8:30 AM, Jarkko Sakkinen wrote:
> > > >> Does this code run when I type "make kselftest"? If not, I think we
> > > >> should rectify that.
> > > > No, it doesn't. It is just my backup for the non-SDK user space code
> > > > that I've made that I will use to fork my user space SGX projects in
> > > > the future.
> > > >
> > > > I can work-out a selftest (and provide a new patch in the series) but
> > > > I'm still wondering what the enclave should do. I would suggest that
> > > > we start with an enclave that does just EEXIT and nothing else.
> > >
> > > Yeah, that's a start. But, a good selftest would include things like
> > > faults and error conditions.
> >
> > Great. We can add more entry points to the enclave for different tests
> > but I'll start with a bare minimum. And yeah but ever goes into next
> > version I'll document the fault handling.
>
> For the v17 I'll add exactly two test cases:
>
> 1. EENTER/EEXIT
> 2. EENTER/exception
>
> So that it will easier to evaluate and demonstrate exception handling.
>
> /Jarkko
Here is my test program now:
https://github.com/jsakkine-intel/sgx-selftest
It is ~1100 lines ATM. Next I'll deploy it to the kernel tree. It has
only (1) now but I'll add (2) too when I convert this to a kernel patch
(probably by doing sgx_call() with a NULL pointer).
/Jarkko