Extend the SEV library to include support for SNP ioctl() wrappers, which aid in launching and interacting with a SEV-SNP guest.
Signed-off-by: Pratik R. Sampat prsampat@amd.com --- v4..v5 * encrypt_region() cleanup of code flow * minor changes to comments --- --- tools/testing/selftests/kvm/include/x86/sev.h | 49 ++++++++++- tools/testing/selftests/kvm/lib/x86/sev.c | 82 +++++++++++++++++-- 2 files changed, 125 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86/sev.h b/tools/testing/selftests/kvm/include/x86/sev.h index faed91435963..fd5d5261e10e 100644 --- a/tools/testing/selftests/kvm/include/x86/sev.h +++ b/tools/testing/selftests/kvm/include/x86/sev.h @@ -22,9 +22,20 @@ enum sev_guest_state { SEV_GUEST_STATE_RUNNING, };
+/* Minimum firmware version required for the SEV-SNP support */ +#define SNP_MIN_API_MAJOR 1 +#define SNP_MIN_API_MINOR 51 + #define SEV_POLICY_NO_DBG (1UL << 0) #define SEV_POLICY_ES (1UL << 2)
+#define SNP_POLICY_SMT (1ULL << 16) +#define SNP_POLICY_RSVD_MBO (1ULL << 17) +#define SNP_POLICY_DBG (1ULL << 19) + +#define SNP_FW_VER_MINOR(min) ((uint8_t)(min) << 0) +#define SNP_FW_VER_MAJOR(maj) ((uint8_t)(maj) << 8) + #define GHCB_MSR_TERM_REQ 0x100
#define VMGEXIT() { __asm__ __volatile__("rep; vmmcall"); } @@ -36,13 +47,35 @@ bool is_sev_snp_vm(struct kvm_vm *vm); void sev_vm_launch(struct kvm_vm *vm, uint32_t policy); void sev_vm_launch_measure(struct kvm_vm *vm, uint8_t *measurement); void sev_vm_launch_finish(struct kvm_vm *vm); +void snp_vm_launch_start(struct kvm_vm *vm, uint64_t policy); +void snp_vm_launch_update(struct kvm_vm *vm); +void snp_vm_launch_finish(struct kvm_vm *vm);
struct kvm_vm *vm_sev_create_with_one_vcpu(uint32_t type, void *guest_code, struct kvm_vcpu **cpu); -void vm_sev_launch(struct kvm_vm *vm, uint32_t policy, uint8_t *measurement); +void vm_sev_launch(struct kvm_vm *vm, uint64_t policy, uint8_t *measurement);
kvm_static_assert(SEV_RET_SUCCESS == 0);
+/* + * A SEV-SNP VM requires the policy reserved bit to always be set. + * The SMT policy bit is also required to be set based on SMT being + * available and active on the system. + */ +static inline u64 snp_default_policy(void) +{ + bool smt_active = false; + FILE *f; + + f = fopen("/sys/devices/system/cpu/smt/active", "r"); + if (f) { + smt_active = fgetc(f) - '0'; + fclose(f); + } + + return SNP_POLICY_RSVD_MBO | (smt_active ? SNP_POLICY_SMT : 0); +} + /* * The KVM_MEMORY_ENCRYPT_OP uAPI is utter garbage and takes an "unsigned long" * instead of a proper struct. The size of the parameter is embedded in the @@ -76,6 +109,7 @@ kvm_static_assert(SEV_RET_SUCCESS == 0);
void sev_vm_init(struct kvm_vm *vm); void sev_es_vm_init(struct kvm_vm *vm); +void snp_vm_init(struct kvm_vm *vm);
static inline void sev_register_encrypted_memory(struct kvm_vm *vm, struct userspace_mem_region *region) @@ -99,4 +133,17 @@ static inline void sev_launch_update_data(struct kvm_vm *vm, vm_paddr_t gpa, vm_sev_ioctl(vm, KVM_SEV_LAUNCH_UPDATE_DATA, &update_data); }
+static inline void snp_launch_update_data(struct kvm_vm *vm, vm_paddr_t gpa, + uint64_t hva, uint64_t size, uint8_t type) +{ + struct kvm_sev_snp_launch_update update_data = { + .uaddr = hva, + .gfn_start = gpa >> PAGE_SHIFT, + .len = size, + .type = type, + }; + + vm_sev_ioctl(vm, KVM_SEV_SNP_LAUNCH_UPDATE, &update_data); +} + #endif /* SELFTEST_KVM_SEV_H */ diff --git a/tools/testing/selftests/kvm/lib/x86/sev.c b/tools/testing/selftests/kvm/lib/x86/sev.c index 280ec42e281b..17d493e9907a 100644 --- a/tools/testing/selftests/kvm/lib/x86/sev.c +++ b/tools/testing/selftests/kvm/lib/x86/sev.c @@ -31,7 +31,8 @@ bool is_sev_vm(struct kvm_vm *vm) * 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) +static void encrypt_region(struct kvm_vm *vm, struct userspace_mem_region *region, + uint8_t page_type) { const struct sparsebit *protected_phy_pages = region->protected_phy_pages; const vm_paddr_t gpa_base = region->region.guest_phys_addr; @@ -41,13 +42,35 @@ static void encrypt_region(struct kvm_vm *vm, struct userspace_mem_region *regio if (!sparsebit_any_set(protected_phy_pages)) return;
- sev_register_encrypted_memory(vm, region); + if (!is_sev_snp_vm(vm)) + sev_register_encrypted_memory(vm, region);
sparsebit_for_each_set_range(protected_phy_pages, i, j) { const uint64_t size = (j - i + 1) * vm->page_size; const uint64_t offset = (i - lowest_page_in_region) * vm->page_size;
- sev_launch_update_data(vm, gpa_base + offset, size); + if (is_sev_snp_vm(vm)) { + snp_launch_update_data(vm, gpa_base + offset, + (uint64_t)addr_gpa2hva(vm, gpa_base + offset), + size, page_type); + } else { + sev_launch_update_data(vm, gpa_base + offset, size); + } + } +} + +static void privatize_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, j; + + sparsebit_for_each_set_range(protected_phy_pages, i, j) { + const uint64_t size = (j - i + 1) * vm->page_size; + const uint64_t offset = (i - lowest_page_in_region) * vm->page_size; + + vm_mem_set_private(vm, gpa_base + offset, size); } }
@@ -77,6 +100,14 @@ void sev_es_vm_init(struct kvm_vm *vm) } }
+void snp_vm_init(struct kvm_vm *vm) +{ + struct kvm_sev_init init = { 0 }; + + assert(vm->type == KVM_X86_SNP_VM); + vm_sev_ioctl(vm, KVM_SEV_INIT2, &init); +} + void sev_vm_launch(struct kvm_vm *vm, uint32_t policy) { struct kvm_sev_launch_start launch_start = { @@ -93,7 +124,7 @@ void sev_vm_launch(struct kvm_vm *vm, uint32_t policy) TEST_ASSERT_EQ(status.state, SEV_GUEST_STATE_LAUNCH_UPDATE);
hash_for_each(vm->regions.slot_hash, ctr, region, slot_node) - encrypt_region(vm, region); + encrypt_region(vm, region, 0);
if (policy & SEV_POLICY_ES) vm_sev_ioctl(vm, KVM_SEV_LAUNCH_UPDATE_VMSA, NULL); @@ -129,6 +160,35 @@ void sev_vm_launch_finish(struct kvm_vm *vm) TEST_ASSERT_EQ(status.state, SEV_GUEST_STATE_RUNNING); }
+void snp_vm_launch_start(struct kvm_vm *vm, uint64_t policy) +{ + struct kvm_sev_snp_launch_start launch_start = { + .policy = policy, + }; + + vm_sev_ioctl(vm, KVM_SEV_SNP_LAUNCH_START, &launch_start); +} + +void snp_vm_launch_update(struct kvm_vm *vm) +{ + struct userspace_mem_region *region; + int ctr; + + hash_for_each(vm->regions.slot_hash, ctr, region, slot_node) { + privatize_region(vm, region); + encrypt_region(vm, region, KVM_SEV_SNP_PAGE_TYPE_NORMAL); + } + + vm->arch.is_pt_protected = true; +} + +void snp_vm_launch_finish(struct kvm_vm *vm) +{ + struct kvm_sev_snp_launch_finish launch_finish = { 0 }; + + vm_sev_ioctl(vm, KVM_SEV_SNP_LAUNCH_FINISH, &launch_finish); +} + struct kvm_vm *vm_sev_create_with_one_vcpu(uint32_t type, void *guest_code, struct kvm_vcpu **cpu) { @@ -145,8 +205,20 @@ struct kvm_vm *vm_sev_create_with_one_vcpu(uint32_t type, void *guest_code, return vm; }
-void vm_sev_launch(struct kvm_vm *vm, uint32_t policy, uint8_t *measurement) +void vm_sev_launch(struct kvm_vm *vm, uint64_t policy, uint8_t *measurement) { + if (is_sev_snp_vm(vm)) { + vm_enable_cap(vm, KVM_CAP_EXIT_HYPERCALL, (1 << KVM_HC_MAP_GPA_RANGE)); + + snp_vm_launch_start(vm, policy); + + snp_vm_launch_update(vm); + + snp_vm_launch_finish(vm); + + return; + } + sev_vm_launch(vm, policy);
if (!measurement)