Add interfaces to allow tests to create SEV guests. The additional
requirements for SEV guests PTs and other state is encapsulated by the
new vm_sev_create_with_one_vcpu() function. This can future be
generalized for more vCPUs but the first set of SEV selftests in this
series only uses a single vCPU.
Cc: Paolo Bonzini <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Vishal Annapurve <[email protected]>
Cc: Ackerley Tng <[email protected]>
cc: Andrew Jones <[email protected]>
Originally-by: Michael Roth <[email protected]>
Co-developed-by: Ackerley Tng <[email protected]>
Signed-off-by: Peter Gonda <[email protected]>
---
tools/arch/x86/include/asm/kvm_host.h | 1 +
tools/testing/selftests/kvm/Makefile | 3 +-
.../selftests/kvm/include/kvm_util_base.h | 15 +-
.../selftests/kvm/include/x86_64/processor.h | 1 +
.../selftests/kvm/include/x86_64/sev.h | 27 ++
tools/testing/selftests/kvm/lib/kvm_util.c | 8 +-
.../selftests/kvm/lib/x86_64/processor.c | 45 +++-
tools/testing/selftests/kvm/lib/x86_64/sev.c | 254 ++++++++++++++++++
8 files changed, 343 insertions(+), 11 deletions(-)
create mode 100644 tools/testing/selftests/kvm/include/x86_64/sev.h
create mode 100644 tools/testing/selftests/kvm/lib/x86_64/sev.c
diff --git a/tools/arch/x86/include/asm/kvm_host.h b/tools/arch/x86/include/asm/kvm_host.h
index d8f48fe835fb..c95041e92fb5 100644
--- a/tools/arch/x86/include/asm/kvm_host.h
+++ b/tools/arch/x86/include/asm/kvm_host.h
@@ -8,6 +8,7 @@
struct kvm_vm_arch {
uint64_t c_bit;
uint64_t s_bit;
+ bool is_pt_protected;
};
#endif // _TOOLS_LINUX_ASM_X86_KVM_HOST_H
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 1750f91dd936..b7cfb15712d1 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -39,6 +39,7 @@ LIBKVM_x86_64 += lib/x86_64/processor.c
LIBKVM_x86_64 += lib/x86_64/svm.c
LIBKVM_x86_64 += lib/x86_64/ucall.c
LIBKVM_x86_64 += lib/x86_64/vmx.c
+LIBKVM_x86_64 += lib/x86_64/sev.c
LIBKVM_aarch64 += lib/aarch64/gic.c
LIBKVM_aarch64 += lib/aarch64/gic_v3.c
@@ -199,7 +200,7 @@ CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \
-fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \
-I$(LINUX_TOOL_ARCH_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude \
-I$(<D) -Iinclude/$(ARCH_DIR) -I ../rseq -I.. $(EXTRA_CFLAGS) \
- $(KHDR_INCLUDES)
+ $(KHDR_INCLUDES) -static -gdwarf-4
no-pie-option := $(call try-run, echo 'int main(void) { return 0; }' | \
$(CC) -Werror $(CFLAGS) -no-pie -x c - -o "$$TMP", -no-pie)
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 5f3150ecfbbf..b5283bcc1d02 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -89,6 +89,13 @@ enum kvm_mem_region_type {
NR_MEM_REGIONS,
};
+/* VM protection policy/configuration. */
+struct protected_vm {
+ bool enabled;
+ bool has_protected_bit;
+ int8_t protected_bit;
+};
+
struct kvm_vm {
int mode;
unsigned long type;
@@ -711,6 +718,10 @@ static inline vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
return _vm_phy_pages_alloc(vm, num, paddr_min, memslot, vm->protected);
}
+uint64_t vm_nr_pages_required(enum vm_guest_mode mode,
+ uint32_t nr_runnable_vcpus,
+ uint64_t extra_mem_pages);
+
/*
* ____vm_create() does KVM_CREATE_VM and little else. __vm_create() also
* loads the test binary into guest memory and creates an IRQ chip (x86 only).
@@ -767,8 +778,8 @@ unsigned long vm_compute_max_gfn(struct kvm_vm *vm);
unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size);
unsigned int vm_num_host_pages(enum vm_guest_mode mode, unsigned int num_guest_pages);
unsigned int vm_num_guest_pages(enum vm_guest_mode mode, unsigned int num_host_pages);
-static inline unsigned int
-vm_adjust_num_guest_pages(enum vm_guest_mode mode, unsigned int num_guest_pages)
+static inline unsigned int vm_adjust_num_guest_pages(enum vm_guest_mode mode,
+ unsigned int num_guest_pages)
{
unsigned int n;
n = vm_num_guest_pages(mode, vm_num_host_pages(mode, num_guest_pages));
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 2a5f47d51388..1c72fb5672a9 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -916,6 +916,7 @@ static inline void vcpu_set_msr(struct kvm_vcpu *vcpu, uint64_t msr_index,
void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits);
+void kvm_init_vm_address_properties(struct kvm_vm *vm);
bool vm_is_unrestricted_guest(struct kvm_vm *vm);
struct ex_regs {
diff --git a/tools/testing/selftests/kvm/include/x86_64/sev.h b/tools/testing/selftests/kvm/include/x86_64/sev.h
new file mode 100644
index 000000000000..e212b032cd77
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/x86_64/sev.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Helpers used for SEV guests
+ *
+ */
+#ifndef SELFTEST_KVM_SEV_H
+#define SELFTEST_KVM_SEV_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "kvm_util.h"
+
+#define CPUID_MEM_ENC_LEAF 0x8000001f
+#define CPUID_EBX_CBIT_MASK 0x3f
+
+#define SEV_POLICY_NO_DBG (1UL << 0)
+#define SEV_POLICY_ES (1UL << 2)
+
+bool is_kvm_sev_supported(void);
+
+void sev_vm_init(struct kvm_vm *vm);
+
+struct kvm_vm *vm_sev_create_with_one_vcpu(uint32_t policy, void *guest_code,
+ struct kvm_vcpu **cpu);
+
+#endif /* SELFTEST_KVM_SEV_H */
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 0d0a7ad7632d..99983a5c5558 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -151,6 +151,7 @@ const char *vm_guest_mode_string(uint32_t i)
[VM_MODE_P40V48_16K] = "PA-bits:40, VA-bits:48, 16K pages",
[VM_MODE_P40V48_64K] = "PA-bits:40, VA-bits:48, 64K pages",
[VM_MODE_PXXV48_4K] = "PA-bits:ANY, VA-bits:48, 4K pages",
+ [VM_MODE_PXXV48_4K_SEV] = "PA-bits:ANY, VA-bits:48, 4K pages",
[VM_MODE_P47V64_4K] = "PA-bits:47, VA-bits:64, 4K pages",
[VM_MODE_P44V64_4K] = "PA-bits:44, VA-bits:64, 4K pages",
[VM_MODE_P36V48_4K] = "PA-bits:36, VA-bits:48, 4K pages",
@@ -176,6 +177,7 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
[VM_MODE_P40V48_16K] = { 40, 48, 0x4000, 14 },
[VM_MODE_P40V48_64K] = { 40, 48, 0x10000, 16 },
[VM_MODE_PXXV48_4K] = { 0, 0, 0x1000, 12 },
+ [VM_MODE_PXXV48_4K_SEV] = { 0, 0, 0x1000, 12 },
[VM_MODE_P47V64_4K] = { 47, 64, 0x1000, 12 },
[VM_MODE_P44V64_4K] = { 44, 64, 0x1000, 12 },
[VM_MODE_P36V48_4K] = { 36, 48, 0x1000, 12 },
@@ -254,9 +256,11 @@ struct kvm_vm *____vm_create(enum vm_guest_mode mode)
case VM_MODE_P36V47_16K:
vm->pgtable_levels = 3;
break;
+ case VM_MODE_PXXV48_4K_SEV:
case VM_MODE_PXXV48_4K:
#ifdef __x86_64__
kvm_get_cpu_address_width(&vm->pa_bits, &vm->va_bits);
+ kvm_init_vm_address_properties(vm);
/*
* Ignore KVM support for 5-level paging (vm->va_bits == 57),
* it doesn't take effect unless a CR4.LA57 is set, which it
@@ -270,7 +274,7 @@ struct kvm_vm *____vm_create(enum vm_guest_mode mode)
vm->pgtable_levels = 4;
vm->va_bits = 48;
#else
- TEST_FAIL("VM_MODE_PXXV48_4K not supported on non-x86 platforms");
+ TEST_FAIL("VM_MODE_PXXV48_4K* not supported on non-x86 platforms");
#endif
break;
case VM_MODE_P47V64_4K:
@@ -303,7 +307,7 @@ struct kvm_vm *____vm_create(enum vm_guest_mode mode)
return vm;
}
-static uint64_t vm_nr_pages_required(enum vm_guest_mode mode,
+uint64_t vm_nr_pages_required(enum vm_guest_mode mode,
uint32_t nr_runnable_vcpus,
uint64_t extra_mem_pages)
{
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index d03cefd9f6cd..557146ba85a8 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -8,6 +8,7 @@
#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"
+#include "sev.h"
#ifndef NUM_INTERRUPTS
#define NUM_INTERRUPTS 256
@@ -119,10 +120,16 @@ bool kvm_is_tdp_enabled(void)
return get_kvm_amd_param_bool("npt");
}
+static void assert_supported_guest_mode(struct kvm_vm *vm)
+{
+ TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K || vm->mode == VM_MODE_PXXV48_4K_SEV,
+ "Attempt to use unknown or unsupported guest mode, mode: 0x%x",
+ vm->mode);
+}
+
void virt_arch_pgd_alloc(struct kvm_vm *vm)
{
- TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
- "unknown or unsupported guest mode, mode: 0x%x", vm->mode);
+ assert_supported_guest_mode(vm);
/* If needed, create page map l4 table. */
if (!vm->pgd_created) {
@@ -186,8 +193,7 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level)
uint64_t *pml4e, *pdpe, *pde;
uint64_t *pte;
- TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K,
- "Unknown or unsupported guest mode, mode: 0x%x", vm->mode);
+ assert_supported_guest_mode(vm);
TEST_ASSERT((vaddr % pg_size) == 0,
"Virtual address not aligned,\n"
@@ -273,11 +279,14 @@ uint64_t *__vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr,
{
uint64_t *pml4e, *pdpe, *pde;
+ TEST_ASSERT(
+ !vm->arch.is_pt_protected,
+ "Protected guests have their page tables protected so gva2gpa conversions are not possible.");
+
TEST_ASSERT(*level >= PG_LEVEL_NONE && *level < PG_LEVEL_NUM,
"Invalid PG_LEVEL_* '%d'", *level);
- TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
- "unknown or unsupported guest mode, mode: 0x%x", vm->mode);
+ assert_supported_guest_mode(vm);
TEST_ASSERT(sparsebit_is_set(vm->vpages_valid,
(vaddr >> vm->page_shift)),
"Invalid virtual address, vaddr: 0x%lx",
@@ -543,6 +552,7 @@ static void vcpu_setup(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
kvm_setup_gdt(vm, &sregs.gdt);
switch (vm->mode) {
+ case VM_MODE_PXXV48_4K_SEV:
case VM_MODE_PXXV48_4K:
sregs.cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
sregs.cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR;
@@ -566,6 +576,10 @@ static void vcpu_setup(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
void kvm_arch_vm_post_create(struct kvm_vm *vm)
{
vm_create_irqchip(vm);
+
+ if (vm->mode == VM_MODE_PXXV48_4K_SEV) {
+ sev_vm_init(vm);
+ }
}
struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
@@ -1050,6 +1064,25 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)
}
}
+static void configure_sev_pte_masks(struct kvm_vm *vm)
+{
+ uint32_t eax, ebx, ecx, edx, enc_bit;
+
+ cpuid(CPUID_MEM_ENC_LEAF, &eax, &ebx, &ecx, &edx);
+ enc_bit = ebx & CPUID_EBX_CBIT_MASK;
+
+ vm->arch.c_bit = 1ULL << enc_bit;
+ vm->protected = true;
+ vm->gpa_protected_mask = vm->arch.c_bit;
+}
+
+void kvm_init_vm_address_properties(struct kvm_vm *vm)
+{
+ if (vm->mode == VM_MODE_PXXV48_4K_SEV) {
+ configure_sev_pte_masks(vm);
+ }
+}
+
static void set_idt_entry(struct kvm_vm *vm, int vector, unsigned long addr,
int dpl, unsigned short selector)
{
diff --git a/tools/testing/selftests/kvm/lib/x86_64/sev.c b/tools/testing/selftests/kvm/lib/x86_64/sev.c
new file mode 100644
index 000000000000..3e20f15dd098
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/x86_64/sev.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Helpers used for SEV guests
+ *
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "kvm_util.h"
+#include "svm_util.h"
+#include "linux/psp-sev.h"
+#include "processor.h"
+#include "sev.h"
+
+#define SEV_FW_REQ_VER_MAJOR 0
+#define SEV_FW_REQ_VER_MINOR 17
+
+enum sev_guest_state {
+ SEV_GSTATE_UNINIT = 0,
+ SEV_GSTATE_LUPDATE,
+ SEV_GSTATE_LSECRET,
+ SEV_GSTATE_RUNNING,
+};
+
+static void sev_ioctl(int cmd, void *data)
+{
+ int ret;
+ struct sev_issue_cmd arg;
+
+ arg.cmd = cmd;
+ arg.data = (unsigned long)data;
+ ret = ioctl(open_sev_dev_path_or_exit(), SEV_ISSUE_CMD, &arg);
+ TEST_ASSERT(ret == 0, "SEV ioctl %d failed, error: %d, fw_error: %d",
+ cmd, ret, arg.error);
+}
+
+static void kvm_sev_ioctl(struct kvm_vm *vm, int cmd, void *data)
+{
+ struct kvm_sev_cmd arg = {0};
+ int ret;
+
+ arg.id = cmd;
+ arg.sev_fd = open_sev_dev_path_or_exit();
+ arg.data = (__u64)data;
+
+ ret = ioctl(vm->fd, KVM_MEMORY_ENCRYPT_OP, &arg);
+ TEST_ASSERT(
+ ret == 0,
+ "SEV KVM ioctl %d failed, rc: %i errno: %i (%s), fw_error: %d",
+ cmd, ret, errno, strerror(errno), arg.error);
+}
+
+static void sev_register_user_region(struct kvm_vm *vm, struct userspace_mem_region *region)
+{
+ struct kvm_enc_region range = {0};
+ int ret;
+
+ range.addr = (__u64)region->region.userspace_addr;
+ ;
+ range.size = region->region.memory_size;
+
+ ret = ioctl(vm->fd, KVM_MEMORY_ENCRYPT_REG_REGION, &range);
+ TEST_ASSERT(ret == 0, "failed to register user range, errno: %i\n",
+ errno);
+}
+
+static void sev_launch_update_data(struct kvm_vm *vm, vm_paddr_t gpa, uint64_t size)
+{
+ struct kvm_sev_launch_update_data ksev_update_data = {0};
+
+ pr_debug("%s: addr: 0x%lx, size: %lu\n", __func__, gpa, size);
+
+ ksev_update_data.uaddr = (__u64)addr_gpa2hva(vm, gpa);
+ ksev_update_data.len = size;
+
+ kvm_sev_ioctl(vm, KVM_SEV_LAUNCH_UPDATE_DATA, &ksev_update_data);
+}
+
+
+/*
+ * Iterate over set ranges within sparsebit @s. In each iteration,
+ * @range_begin and @range_end will take the beginning and end of the set
+ * range, which are of type sparsebit_idx_t.
+ *
+ * For example, if the range [3, 7] (inclusive) is set, within the
+ * iteration,@range_begin will take the value 3 and @range_end will take
+ * the value 7.
+ *
+ * Ensure that there is at least one bit set before using this macro with
+ * sparsebit_any_set(), because sparsebit_first_set() will abort if none
+ * are set.
+ */
+#define sparsebit_for_each_set_range(s, range_begin, range_end) \
+ for (range_begin = sparsebit_first_set(s), \
+ range_end = \
+ sparsebit_next_clear(s, range_begin) - 1; \
+ range_begin && range_end; \
+ range_begin = sparsebit_next_set(s, range_end), \
+ range_end = \
+ sparsebit_next_clear(s, range_begin) - 1)
+
+/*
+ * sparsebit_next_clear() can return 0 if [x, 2**64-1] are all set, and the
+ * -1 would then cause an underflow back to 2**64 - 1. This is expected and
+ * correct.
+ *
+ * If the last range in the sparsebit is [x, y] and we try to iterate,
+ * sparsebit_next_set() will return 0, and sparsebit_next_clear() will try
+ * and find the first range, but that's correct because the condition
+ * expression would cause us to quit the loop.
+ */
+static void encrypt_region(struct kvm_vm *vm, struct userspace_mem_region *region)
+{
+ const struct sparsebit *protected_phy_pages =
+ region->protected_phy_pages;
+ const vm_paddr_t gpa_base = region->region.guest_phys_addr;
+ const sparsebit_idx_t lowest_page_in_region = gpa_base >> vm->page_shift;
+
+ sparsebit_idx_t i;
+ sparsebit_idx_t j;
+
+ if (!sparsebit_any_set(protected_phy_pages))
+ return;
+
+ sev_register_user_region(vm, region);
+
+ sparsebit_for_each_set_range(protected_phy_pages, i, j) {
+ const uint64_t size_to_load = (j - i + 1) * vm->page_size;
+ const uint64_t offset = (i - lowest_page_in_region) * vm->page_size;
+ const uint64_t gpa = gpa_base + offset;
+
+ sev_launch_update_data(vm, gpa, size_to_load);
+ }
+}
+
+static void sev_encrypt(struct kvm_vm *vm)
+{
+ int ctr;
+ struct userspace_mem_region *region;
+
+ hash_for_each(vm->regions.slot_hash, ctr, region, slot_node) {
+ encrypt_region(vm, region);
+ }
+
+ vm->arch.is_pt_protected = true;
+}
+
+bool is_kvm_sev_supported(void)
+{
+ struct sev_user_data_status sev_status;
+
+ sev_ioctl(SEV_PLATFORM_STATUS, &sev_status);
+
+ if (!(sev_status.api_major > SEV_FW_REQ_VER_MAJOR ||
+ (sev_status.api_major == SEV_FW_REQ_VER_MAJOR &&
+ sev_status.api_minor >= SEV_FW_REQ_VER_MINOR))) {
+ pr_info("SEV FW version too old. Have API %d.%d (build: %d), need %d.%d, skipping test.\n",
+ sev_status.api_major, sev_status.api_minor,
+ sev_status.build, SEV_FW_REQ_VER_MAJOR,
+ SEV_FW_REQ_VER_MINOR);
+ return false;
+ }
+
+ return true;
+}
+
+static void sev_vm_launch(struct kvm_vm *vm, uint32_t policy)
+{
+ struct kvm_sev_launch_start ksev_launch_start = {0};
+ struct kvm_sev_guest_status ksev_status;
+
+ ksev_launch_start.policy = policy;
+ kvm_sev_ioctl(vm, KVM_SEV_LAUNCH_START, &ksev_launch_start);
+ kvm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &ksev_status);
+ TEST_ASSERT(ksev_status.policy == policy, "Incorrect guest policy.");
+ TEST_ASSERT(ksev_status.state == SEV_GSTATE_LUPDATE,
+ "Unexpected guest state: %d", ksev_status.state);
+
+ ucall_init(vm, 0);
+
+ sev_encrypt(vm);
+}
+
+static void sev_vm_launch_measure(struct kvm_vm *vm, uint8_t *measurement)
+{
+ struct kvm_sev_launch_measure ksev_launch_measure;
+ struct kvm_sev_guest_status ksev_guest_status;
+
+ ksev_launch_measure.len = 256;
+ ksev_launch_measure.uaddr = (__u64)measurement;
+ kvm_sev_ioctl(vm, KVM_SEV_LAUNCH_MEASURE, &ksev_launch_measure);
+
+ kvm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &ksev_guest_status);
+ TEST_ASSERT(ksev_guest_status.state == SEV_GSTATE_LSECRET,
+ "Unexpected guest state: %d", ksev_guest_status.state);
+}
+
+static void sev_vm_launch_finish(struct kvm_vm *vm)
+{
+ struct kvm_sev_guest_status ksev_status;
+
+ kvm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &ksev_status);
+ TEST_ASSERT(ksev_status.state == SEV_GSTATE_LUPDATE ||
+ ksev_status.state == SEV_GSTATE_LSECRET,
+ "Unexpected guest state: %d", ksev_status.state);
+
+ kvm_sev_ioctl(vm, KVM_SEV_LAUNCH_FINISH, NULL);
+
+ kvm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &ksev_status);
+ TEST_ASSERT(ksev_status.state == SEV_GSTATE_RUNNING,
+ "Unexpected guest state: %d", ksev_status.state);
+}
+
+static void sev_vm_measure(struct kvm_vm *vm)
+{
+ uint8_t measurement[512];
+ int i;
+
+ sev_vm_launch_measure(vm, measurement);
+
+ /* TODO: Validate the measurement is as expected. */
+ pr_debug("guest measurement: ");
+ for (i = 0; i < 32; ++i)
+ pr_debug("%02x", measurement[i]);
+ pr_debug("\n");
+}
+
+void sev_vm_init(struct kvm_vm *vm)
+{
+ kvm_sev_ioctl(vm, KVM_SEV_INIT, NULL);
+}
+
+struct kvm_vm *vm_sev_create_with_one_vcpu(uint32_t policy, void *guest_code,
+ struct kvm_vcpu **cpu)
+{
+ enum vm_guest_mode mode = VM_MODE_PXXV48_4K_SEV;
+ struct kvm_vm *vm;
+ struct kvm_vcpu *cpus[1];
+
+ vm = __vm_create_with_vcpus(mode, 1, 0, guest_code, cpus);
+ *cpu = cpus[0];
+
+ sev_vm_launch(vm, policy);
+
+ sev_vm_measure(vm);
+
+ sev_vm_launch_finish(vm);
+
+ pr_info("SEV guest created, policy: 0x%x\n", policy);
+
+ return vm;
+}
--
2.39.0.314.g84b9a713c41-goog
On Tue, Jan 10, 2023, Peter Gonda wrote:
> Add interfaces to allow tests to create SEV guests. The additional
> requirements for SEV guests PTs and other state is encapsulated by the
> new vm_sev_create_with_one_vcpu() function. This can future be
> generalized for more vCPUs but the first set of SEV selftests in this
> series only uses a single vCPU.
>
> Cc: Paolo Bonzini <[email protected]>
> Cc: Sean Christopherson <[email protected]>
> Cc: Vishal Annapurve <[email protected]>
> Cc: Ackerley Tng <[email protected]>
> cc: Andrew Jones <[email protected]>
> Originally-by: Michael Roth <[email protected]>
> Co-developed-by: Ackerley Tng <[email protected]>
> Signed-off-by: Peter Gonda <[email protected]>
>
> ---
> tools/arch/x86/include/asm/kvm_host.h | 1 +
> tools/testing/selftests/kvm/Makefile | 3 +-
> .../selftests/kvm/include/kvm_util_base.h | 15 +-
> .../selftests/kvm/include/x86_64/processor.h | 1 +
> .../selftests/kvm/include/x86_64/sev.h | 27 ++
> tools/testing/selftests/kvm/lib/kvm_util.c | 8 +-
> .../selftests/kvm/lib/x86_64/processor.c | 45 +++-
> tools/testing/selftests/kvm/lib/x86_64/sev.c | 254 ++++++++++++++++++
> 8 files changed, 343 insertions(+), 11 deletions(-)
> create mode 100644 tools/testing/selftests/kvm/include/x86_64/sev.h
> create mode 100644 tools/testing/selftests/kvm/lib/x86_64/sev.c
>
> diff --git a/tools/arch/x86/include/asm/kvm_host.h b/tools/arch/x86/include/asm/kvm_host.h
> index d8f48fe835fb..c95041e92fb5 100644
> --- a/tools/arch/x86/include/asm/kvm_host.h
> +++ b/tools/arch/x86/include/asm/kvm_host.h
> @@ -8,6 +8,7 @@
> struct kvm_vm_arch {
> uint64_t c_bit;
> uint64_t s_bit;
> + bool is_pt_protected;
Leftover crud from a previous version, no? I.e. can't this just use vm->protected?
> };
>
> #endif // _TOOLS_LINUX_ASM_X86_KVM_HOST_H
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index 1750f91dd936..b7cfb15712d1 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -39,6 +39,7 @@ LIBKVM_x86_64 += lib/x86_64/processor.c
> LIBKVM_x86_64 += lib/x86_64/svm.c
> LIBKVM_x86_64 += lib/x86_64/ucall.c
> LIBKVM_x86_64 += lib/x86_64/vmx.c
> +LIBKVM_x86_64 += lib/x86_64/sev.c
>
> LIBKVM_aarch64 += lib/aarch64/gic.c
> LIBKVM_aarch64 += lib/aarch64/gic_v3.c
> @@ -199,7 +200,7 @@ CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \
> -fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \
> -I$(LINUX_TOOL_ARCH_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude \
> -I$(<D) -Iinclude/$(ARCH_DIR) -I ../rseq -I.. $(EXTRA_CFLAGS) \
> - $(KHDR_INCLUDES)
> + $(KHDR_INCLUDES) -static -gdwarf-4
Spurious stuff from your environment, which by the way can just use EXTRA_CFLAGS,
e.g. I build selftests with
EXTRA_CFLAGS="$static -Werror -gdwarf-4"
where $static varies based on the host.
> no-pie-option := $(call try-run, echo 'int main(void) { return 0; }' | \
> $(CC) -Werror $(CFLAGS) -no-pie -x c - -o "$$TMP", -no-pie)
> diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
> index 5f3150ecfbbf..b5283bcc1d02 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util_base.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
> @@ -89,6 +89,13 @@ enum kvm_mem_region_type {
> NR_MEM_REGIONS,
> };
>
> +/* VM protection policy/configuration. */
> +struct protected_vm {
> + bool enabled;
> + bool has_protected_bit;
> + int8_t protected_bit;
> +};
More leftover crud.
> +
> struct kvm_vm {
> int mode;
> unsigned long type;
> @@ -711,6 +718,10 @@ static inline vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
> return _vm_phy_pages_alloc(vm, num, paddr_min, memslot, vm->protected);
> }
>
> +uint64_t vm_nr_pages_required(enum vm_guest_mode mode,
> + uint32_t nr_runnable_vcpus,
> + uint64_t extra_mem_pages);
> +
Making vm_nr_pages_required() globally visible is no longer needed (upstream
changed).
> +#endif /* SELFTEST_KVM_SEV_H */
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 0d0a7ad7632d..99983a5c5558 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -151,6 +151,7 @@ const char *vm_guest_mode_string(uint32_t i)
> [VM_MODE_P40V48_16K] = "PA-bits:40, VA-bits:48, 16K pages",
> [VM_MODE_P40V48_64K] = "PA-bits:40, VA-bits:48, 64K pages",
> [VM_MODE_PXXV48_4K] = "PA-bits:ANY, VA-bits:48, 4K pages",
> + [VM_MODE_PXXV48_4K_SEV] = "PA-bits:ANY, VA-bits:48, 4K pages",
> [VM_MODE_P47V64_4K] = "PA-bits:47, VA-bits:64, 4K pages",
> [VM_MODE_P44V64_4K] = "PA-bits:44, VA-bits:64, 4K pages",
> [VM_MODE_P36V48_4K] = "PA-bits:36, VA-bits:48, 4K pages",
> @@ -176,6 +177,7 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
> [VM_MODE_P40V48_16K] = { 40, 48, 0x4000, 14 },
> [VM_MODE_P40V48_64K] = { 40, 48, 0x10000, 16 },
> [VM_MODE_PXXV48_4K] = { 0, 0, 0x1000, 12 },
> + [VM_MODE_PXXV48_4K_SEV] = { 0, 0, 0x1000, 12 },
Aha! An excuse to use my "mode overloading" idea[*]. Similar to concerns I had with
the UPM restricted memory stuff, adding dedicated enums for modifier is going to
be a maintenance problem. So rather than have VM_MODE_PXXV48_4K_SEV, I propose we
split @mode into a set of masks and then have a "primary mode" and a "vm type".
Note, Andrew requested using a struct, so this may need a fair bit of massaging.
[*] https://lore.kernel.org/all/[email protected]
> +static void assert_supported_guest_mode(struct kvm_vm *vm)
> +{
> + TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K || vm->mode == VM_MODE_PXXV48_4K_SEV,
> + "Attempt to use unknown or unsupported guest mode, mode: 0x%x",
> + vm->mode);
These changes all go away if we use a modifier for the VM type.
> +}
> +
> void virt_arch_pgd_alloc(struct kvm_vm *vm)
> {
> - TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
> - "unknown or unsupported guest mode, mode: 0x%x", vm->mode);
> + assert_supported_guest_mode(vm);
>
> /* If needed, create page map l4 table. */
> if (!vm->pgd_created) {
> @@ -186,8 +193,7 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level)
> uint64_t *pml4e, *pdpe, *pde;
> uint64_t *pte;
>
> - TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K,
> - "Unknown or unsupported guest mode, mode: 0x%x", vm->mode);
> + assert_supported_guest_mode(vm);
>
> TEST_ASSERT((vaddr % pg_size) == 0,
> "Virtual address not aligned,\n"
> @@ -273,11 +279,14 @@ uint64_t *__vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr,
> {
> uint64_t *pml4e, *pdpe, *pde;
>
> + TEST_ASSERT(
> + !vm->arch.is_pt_protected,
> + "Protected guests have their page tables protected so gva2gpa conversions are not possible.");
Eww, Google3 C++ "readability".
TEST_ASSERT(!vm->protected,
"Walking page tables of protected guests is impossible");
> @@ -566,6 +576,10 @@ static void vcpu_setup(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
> void kvm_arch_vm_post_create(struct kvm_vm *vm)
> {
> vm_create_irqchip(vm);
> +
> + if (vm->mode == VM_MODE_PXXV48_4K_SEV) {
Unnecesary braces.
> + sev_vm_init(vm);
> + }
> }
>
> struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id,
> @@ -1050,6 +1064,25 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)
> }
> }
>
> +static void configure_sev_pte_masks(struct kvm_vm *vm)
> +{
> + uint32_t eax, ebx, ecx, edx, enc_bit;
> +
> + cpuid(CPUID_MEM_ENC_LEAF, &eax, &ebx, &ecx, &edx);
> + enc_bit = ebx & CPUID_EBX_CBIT_MASK;
Add X86_PROPERTY_SEV_C_BIT (or something along those lines).
> +
> + vm->arch.c_bit = 1ULL << enc_bit;
> + vm->protected = true;
> + vm->gpa_protected_mask = vm->arch.c_bit;
> +}
> +
> +void kvm_init_vm_address_properties(struct kvm_vm *vm)
> +{
> + if (vm->mode == VM_MODE_PXXV48_4K_SEV) {
Unnecessary braces as written, but having a helper is just silly.
> + configure_sev_pte_masks(vm);
if (vm->type == VM_TYPE_SEV) {
vm->protected = true;
vm->arch.c_bit = this_cpu_property(X86_PROPERTY_SEV_C_BIT);
vm->gpa_tag_mask = vm->arch.c_bit;
}
> + }
> +}
...
> +static void sev_ioctl(int cmd, void *data)
> +{
> + int ret;
> + struct sev_issue_cmd arg;
> +
> + arg.cmd = cmd;
> + arg.data = (unsigned long)data;
> + ret = ioctl(open_sev_dev_path_or_exit(), SEV_ISSUE_CMD, &arg);
> + TEST_ASSERT(ret == 0, "SEV ioctl %d failed, error: %d, fw_error: %d",
> + cmd, ret, arg.error);
This leaks the fd, and it should use kvm_ioctl(). Yean, it's not technically a
KVM ioctl(), but there's no need to reinvent the wheel.
> +}
> +
> +static void kvm_sev_ioctl(struct kvm_vm *vm, int cmd, void *data)
> +{
> + struct kvm_sev_cmd arg = {0};
> + int ret;
> +
> + arg.id = cmd;
> + arg.sev_fd = open_sev_dev_path_or_exit();
> + arg.data = (__u64)data;
Use a struct initializer:
struct kvm_sev_cmd sev_cmd = {
.id = cmd,
.sev_fd = vm->sev_fd,
.data = (unsigned long)data,
};
> +
> + ret = ioctl(vm->fd, KVM_MEMORY_ENCRYPT_OP, &arg);
> + TEST_ASSERT(
> + ret == 0,
> + "SEV KVM ioctl %d failed, rc: %i errno: %i (%s), fw_error: %d",
> + cmd, ret, errno, strerror(errno), arg.error);
Google3 horrors aside, just use vm_ioctl().
vm_ioctl(vm, KVM_MEMORY_ENCRYPT_OP, &sev_cmd);
> +}
> +
> +static void sev_register_user_region(struct kvm_vm *vm, struct userspace_mem_region *region)
> +{
> + struct kvm_enc_region range = {0};
> + int ret;
> +
> + range.addr = (__u64)region->region.userspace_addr;
> + ;
> + range.size = region->region.memory_size;
> +
> + ret = ioctl(vm->fd, KVM_MEMORY_ENCRYPT_REG_REGION, &range);
> + TEST_ASSERT(ret == 0, "failed to register user range, errno: %i\n",
> + errno);
See above.
> +}
> +
> +static void sev_launch_update_data(struct kvm_vm *vm, vm_paddr_t gpa, uint64_t size)
> +{
> + struct kvm_sev_launch_update_data ksev_update_data = {0};
These are _local_ variables, there's no need to namespace them, i.e. delete kvev_.
> +
> + pr_debug("%s: addr: 0x%lx, size: %lu\n", __func__, gpa, size);
> +
> + ksev_update_data.uaddr = (__u64)addr_gpa2hva(vm, gpa);
> + ksev_update_data.len = size;
Struct initializer.
> +
> + kvm_sev_ioctl(vm, KVM_SEV_LAUNCH_UPDATE_DATA, &ksev_update_data);
> +}
> +
> +
> +/*
> + * Iterate over set ranges within sparsebit @s. In each iteration,
> + * @range_begin and @range_end will take the beginning and end of the set
> + * range, which are of type sparsebit_idx_t.
> + *
> + * For example, if the range [3, 7] (inclusive) is set, within the
> + * iteration,@range_begin will take the value 3 and @range_end will take
> + * the value 7.
> + *
> + * Ensure that there is at least one bit set before using this macro with
> + * sparsebit_any_set(), because sparsebit_first_set() will abort if none
> + * are set.
> + */
> +#define sparsebit_for_each_set_range(s, range_begin, range_end) \
> + for (range_begin = sparsebit_first_set(s), \
> + range_end = \
> + sparsebit_next_clear(s, range_begin) - 1; \
> + range_begin && range_end; \
> + range_begin = sparsebit_next_set(s, range_end), \
> + range_end = \
> + sparsebit_next_clear(s, range_begin) - 1)
This belongs in tools/testing/selftests/kvm/include/sparsebit.h.
> +
> +/*
> + * sparsebit_next_clear() can return 0 if [x, 2**64-1] are all set, and the
> + * -1 would then cause an underflow back to 2**64 - 1. This is expected and
> + * correct.
> + *
> + * If the last range in the sparsebit is [x, y] and we try to iterate,
> + * sparsebit_next_set() will return 0, and sparsebit_next_clear() will try
> + * and find the first range, but that's correct because the condition
> + * expression would cause us to quit the loop.
> + */
> +static void encrypt_region(struct kvm_vm *vm, struct userspace_mem_region *region)
> +{
> + const struct sparsebit *protected_phy_pages =
> + region->protected_phy_pages;
Don't wrap, 3 chars in the case is fine. You didn't wrap two lines below, which
runs over by 2 chars, so spontaneous combustion is unlikely.
> + const vm_paddr_t gpa_base = region->region.guest_phys_addr;
> + const sparsebit_idx_t lowest_page_in_region = gpa_base >> vm->page_shift;
> +
> + sparsebit_idx_t i;
> + sparsebit_idx_t j;
> +
> + if (!sparsebit_any_set(protected_phy_pages))
> + return;
> +
> + sev_register_user_region(vm, region);
> +
> + sparsebit_for_each_set_range(protected_phy_pages, i, j) {
> + const uint64_t size_to_load = (j - i + 1) * vm->page_size;
> + const uint64_t offset = (i - lowest_page_in_region) * vm->page_size;
> + const uint64_t gpa = gpa_base + offset;
> +
> + sev_launch_update_data(vm, gpa, size_to_load);
> + }
> +}
> +
> +static void sev_encrypt(struct kvm_vm *vm)
Open code this in its one caller.
> +{
> + int ctr;
> + struct userspace_mem_region *region;
> +
> + hash_for_each(vm->regions.slot_hash, ctr, region, slot_node) {
> + encrypt_region(vm, region);
> + }
> +
> + vm->arch.is_pt_protected = true;
Ah, that's why is_pt_protected exists. Yeah, no. I despise that SEV doesn't
actually protect guest memory until a magic command is issued. Unless there is a
really, _really_ good reason not to treat the VM as fully protected from time zero,
let's ignore that detail in selftests.
> +}
> +
> +bool is_kvm_sev_supported(void)
> +{
> + struct sev_user_data_status sev_status;
> +
> + sev_ioctl(SEV_PLATFORM_STATUS, &sev_status);
> +
> + if (!(sev_status.api_major > SEV_FW_REQ_VER_MAJOR ||
> + (sev_status.api_major == SEV_FW_REQ_VER_MAJOR &&
> + sev_status.api_minor >= SEV_FW_REQ_VER_MINOR))) {
This needs a comment explaining what on earth the major+minor stuff is, and why
we care.
> + pr_info("SEV FW version too old. Have API %d.%d (build: %d), need %d.%d, skipping test.\n",
> + sev_status.api_major, sev_status.api_minor,
> + sev_status.build, SEV_FW_REQ_VER_MAJOR,
> + SEV_FW_REQ_VER_MINOR);
The pr_info() seems kinda pointless. If someone is running these and the firmware
is too old, I assume they're going to have to do a lot of dirty work to get the
firmware updated. And this is much easier on the eyes:
struct sev_user_data_status sev_status;
sev_ioctl(SEV_PLATFORM_STATUS, &sev_status);
return sev_status.api_major > SEV_FW_REQ_VER_MAJOR ||
(sev_status.api_major == SEV_FW_REQ_VER_MAJOR &&
sev_status.api_minor >= SEV_FW_REQ_VER_MINOR);
If the pr_info() really does add value, then do something like:
supported = sev_status.api_major > SEV_FW_REQ_VER_MAJOR ||
(sev_status.api_major == SEV_FW_REQ_VER_MAJOR &&
sev_status.api_minor >= SEV_FW_REQ_VER_MINOR);
if (!supported)
pr_info();
return supported;
> +static void sev_vm_launch(struct kvm_vm *vm, uint32_t policy)
> +{
> + struct kvm_sev_launch_start ksev_launch_start = {0};
> + struct kvm_sev_guest_status ksev_status;
See above.
> +
> + ksev_launch_start.policy = policy;
> + kvm_sev_ioctl(vm, KVM_SEV_LAUNCH_START, &ksev_launch_start);
> + kvm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &ksev_status);
> + TEST_ASSERT(ksev_status.policy == policy, "Incorrect guest policy.");
> + TEST_ASSERT(ksev_status.state == SEV_GSTATE_LUPDATE,
> + "Unexpected guest state: %d", ksev_status.state);
Print the expected vs. actual.
> +
> + ucall_init(vm, 0);
> +
> + sev_encrypt(vm);
> +}
> +
> +static void sev_vm_launch_measure(struct kvm_vm *vm, uint8_t *measurement)
> +{
> + struct kvm_sev_launch_measure ksev_launch_measure;
> + struct kvm_sev_guest_status ksev_guest_status;
> +
> + ksev_launch_measure.len = 256;
> + ksev_launch_measure.uaddr = (__u64)measurement;
> + kvm_sev_ioctl(vm, KVM_SEV_LAUNCH_MEASURE, &ksev_launch_measure);
See above.
> +
> + kvm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &ksev_guest_status);
> + TEST_ASSERT(ksev_guest_status.state == SEV_GSTATE_LSECRET,
> + "Unexpected guest state: %d", ksev_guest_status.state);
Expected vs. actual