From: Sean Christopherson <[email protected]>
Add X86_FEATURE_SGX from CPUID.(EAX=7, ECX=1), which informs whether the
CPU has SGX.
Add X86_FEATURE_SGX1 and X86_FEATURE_SGX2 from CPUID.(EAX=12H, ECX=0),
which describe the level of SGX support available [1].
Add IA32_FEATURE_CONTROL.SGX_ENABLE. BIOS can use this bit to opt-in SGX
before locking the feature control MSR [2].
[1] Intel SDM: 36.7.2 Intel® SGX Resource Enumeration Leaves
[2] Intel SDM: 36.7.1 Intel® SGX Opt-In Configuration
Reviewed-by: Borislav Petkov <[email protected]>
Acked-by: Jethro Beekman <[email protected]>
Reviewed-by: Darren Kenny <[email protected]>
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/cpufeature.h | 5 +++--
arch/x86/include/asm/cpufeatures.h | 7 ++++++-
arch/x86/include/asm/disabled-features.h | 18 +++++++++++++++---
arch/x86/include/asm/msr-index.h | 1 +
arch/x86/include/asm/required-features.h | 2 +-
arch/x86/kernel/cpu/common.c | 4 ++++
6 files changed, 30 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 59bf91c57aa8..efbdba5170a3 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -30,6 +30,7 @@ enum cpuid_leafs
CPUID_7_ECX,
CPUID_8000_0007_EBX,
CPUID_7_EDX,
+ CPUID_12_EAX,
};
#ifdef CONFIG_X86_FEATURE_NAMES
@@ -89,7 +90,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \
CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \
REQUIRED_MASK_CHECK || \
- BUILD_BUG_ON_ZERO(NCAPINTS != 19))
+ BUILD_BUG_ON_ZERO(NCAPINTS != 20))
#define DISABLED_MASK_BIT_SET(feature_bit) \
( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \
@@ -112,7 +113,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \
CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \
DISABLED_MASK_CHECK || \
- BUILD_BUG_ON_ZERO(NCAPINTS != 19))
+ BUILD_BUG_ON_ZERO(NCAPINTS != 20))
#define cpu_has(c, bit) \
(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index dad350d42ecf..7150001d5232 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -13,7 +13,7 @@
/*
* Defines x86 CPU feature bits
*/
-#define NCAPINTS 19 /* N 32-bit words worth of info */
+#define NCAPINTS 20 /* N 32-bit words worth of info */
#define NBUGINTS 1 /* N 32-bit bug flags */
/*
@@ -241,6 +241,7 @@
/* 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 */
@@ -381,6 +382,10 @@
#define X86_FEATURE_CORE_CAPABILITIES (18*32+30) /* "" IA32_CORE_CAPABILITIES MSR */
#define X86_FEATURE_SPEC_CTRL_SSBD (18*32+31) /* "" Speculative Store Bypass Disable */
+/* Intel-defined SGX features, CPUID level 0x00000012:0 (EAX), word 19 */
+#define X86_FEATURE_SGX1 (19*32+ 0) /* SGX1 leaf functions */
+#define X86_FEATURE_SGX2 (19*32+ 1) /* SGX2 leaf functions */
+
/*
* BUG word(s)
*/
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 5861d34f9771..689a100948eb 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -28,13 +28,18 @@
# define DISABLE_CYRIX_ARR (1<<(X86_FEATURE_CYRIX_ARR & 31))
# define DISABLE_CENTAUR_MCR (1<<(X86_FEATURE_CENTAUR_MCR & 31))
# define DISABLE_PCID 0
+# define DISABLE_SGX1 0
+# define DISABLE_SGX2 0
#else
# define DISABLE_VME 0
# define DISABLE_K6_MTRR 0
# define DISABLE_CYRIX_ARR 0
# define DISABLE_CENTAUR_MCR 0
# define DISABLE_PCID (1<<(X86_FEATURE_PCID & 31))
-#endif /* CONFIG_X86_64 */
+# define DISABLE_SGX1 (1<<(X86_FEATURE_SGX1 & 31))
+# define DISABLE_SGX2 (1<<(X86_FEATURE_SGX2 & 31))
+ #endif /* CONFIG_X86_64 */
+
#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
# define DISABLE_PKU 0
@@ -62,6 +67,12 @@
# define DISABLE_ENQCMD (1 << (X86_FEATURE_ENQCMD & 31))
#endif
+#ifdef CONFIG_INTEL_SGX
+# define DISABLE_SGX 0
+#else
+# define DISABLE_SGX (1 << (X86_FEATURE_SGX & 31))
+#endif
+
/*
* Make sure to add features to the correct mask
*/
@@ -74,7 +85,7 @@
#define DISABLED_MASK6 0
#define DISABLED_MASK7 (DISABLE_PTI)
#define DISABLED_MASK8 0
-#define DISABLED_MASK9 (DISABLE_SMAP)
+#define DISABLED_MASK9 (DISABLE_SMAP|DISABLE_SGX)
#define DISABLED_MASK10 0
#define DISABLED_MASK11 0
#define DISABLED_MASK12 0
@@ -85,6 +96,7 @@
DISABLE_ENQCMD)
#define DISABLED_MASK17 0
#define DISABLED_MASK18 0
-#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19)
+#define DISABLED_MASK19 (DISABLE_SGX1|DISABLE_SGX2)
+#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20)
#endif /* _ASM_X86_DISABLED_FEATURES_H */
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 972a34d93505..258d555d22f2 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -609,6 +609,7 @@
#define FEAT_CTL_LOCKED BIT(0)
#define FEAT_CTL_VMX_ENABLED_INSIDE_SMX BIT(1)
#define FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX BIT(2)
+#define FEAT_CTL_SGX_ENABLED BIT(18)
#define FEAT_CTL_LMCE_ENABLED BIT(20)
#define MSR_IA32_TSC_ADJUST 0x0000003b
diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h
index 3ff0d48469f2..6a02e04c90fb 100644
--- a/arch/x86/include/asm/required-features.h
+++ b/arch/x86/include/asm/required-features.h
@@ -101,6 +101,6 @@
#define REQUIRED_MASK16 0
#define REQUIRED_MASK17 0
#define REQUIRED_MASK18 0
-#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19)
+#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20)
#endif /* _ASM_X86_REQUIRED_FEATURES_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 6220fae87263..d940db176901 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -932,6 +932,10 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
c->x86_capability[CPUID_D_1_EAX] = eax;
}
+ /* Additional Intel-defined SGX flags: level 0x00000012 */
+ if (c->cpuid_level >= 0x00000012)
+ c->x86_capability[CPUID_12_EAX] = cpuid_eax(0x00000012);
+
/* AMD-defined flags: level 0x80000001 */
eax = cpuid_eax(0x80000000);
c->extended_cpuid_level = eax;
--
2.25.1
On 10/2/20 9:50 PM, Jarkko Sakkinen wrote:
>
> Add X86_FEATURE_SGX1 and X86_FEATURE_SGX2 from CPUID.(EAX=12H, ECX=0),
> which describe the level of SGX support available [1].
The SDM says there are 6 leaf functions added with SGX2 (SDM Vol 3D
Table 36-2):
ENCLS[EAUG]
ENCLS[EMODPR]
ENCLS[EMODT]
ENCLU[EACCEPT]
ENCLU[EMODPE]
ENCLU[EACCEPTCOPY]
But I don't see *ANY* of those in use in this patch set. I know we
added a bunch of infrastructure around mitigating if EMODPE got *used*,
but does the kernel need to change its behavior if SGX1 vs. SGX2 is
supported?
BTW, the SG2 bit is defined:
Bit 01: SGX2. If 1, Indicates Intel SGX supports the collection
of SGX2 leaf functions.
which makes me think it's for leaf functions only.
On Mon, Oct 19, 2020 at 07:10:58AM -0700, Dave Hansen wrote:
> On 10/2/20 9:50 PM, Jarkko Sakkinen wrote:
> >
> > Add X86_FEATURE_SGX1 and X86_FEATURE_SGX2 from CPUID.(EAX=12H, ECX=0),
> > which describe the level of SGX support available [1].
>
> The SDM says there are 6 leaf functions added with SGX2 (SDM Vol 3D
> Table 36-2):
>
> ENCLS[EAUG]
> ENCLS[EMODPR]
> ENCLS[EMODT]
> ENCLU[EACCEPT]
> ENCLU[EMODPE]
> ENCLU[EACCEPTCOPY]
>
> But I don't see *ANY* of those in use in this patch set. I know we
> added a bunch of infrastructure around mitigating if EMODPE got *used*,
> but does the kernel need to change its behavior if SGX1 vs. SGX2 is
> supported?
>
> BTW, the SG2 bit is defined:
>
> Bit 01: SGX2. If 1, Indicates Intel SGX supports the collection
> of SGX2 leaf functions.
>
> which makes me think it's for leaf functions only.
As mentioned in the other thread, SGX1 hardware takes an erratum on the #PF
behavior of the EPCM, i.e. on SGX2+, EPCM violations generate #PF with
PFEC.SGX=1, whereas SGX1 hardware will #GP.