Consolidate SEV policy bit definitions into a single file. Use include/linux/psp-sev.h to hold the definitions and remove the current definitions from the arch/x86/kvm/svm/sev.c and arch/x86/include/svm.h files. No functional change intended. Signed-off-by: Tom Lendacky --- arch/x86/kvm/svm/sev.c | 16 ++++------------ arch/x86/kvm/svm/svm.h | 3 --- include/linux/psp-sev.h | 19 +++++++++++++++++++ 3 files changed, 23 insertions(+), 15 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 0835c664fbfd..f04589ae76bb 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -65,15 +65,7 @@ module_param_named(ciphertext_hiding_asids, nr_ciphertext_hiding_asids, uint, 04 #define AP_RESET_HOLD_NAE_EVENT 1 #define AP_RESET_HOLD_MSR_PROTO 2 -/* As defined by SEV-SNP Firmware ABI, under "Guest Policy". */ -#define SNP_POLICY_MASK_API_MINOR GENMASK_ULL(7, 0) -#define SNP_POLICY_MASK_API_MAJOR GENMASK_ULL(15, 8) -#define SNP_POLICY_MASK_SMT BIT_ULL(16) -#define SNP_POLICY_MASK_RSVD_MBO BIT_ULL(17) -#define SNP_POLICY_MASK_DEBUG BIT_ULL(19) -#define SNP_POLICY_MASK_SINGLE_SOCKET BIT_ULL(20) - -#define SNP_POLICY_MASK_VALID (SNP_POLICY_MASK_API_MINOR | \ +#define KVM_SNP_POLICY_MASK_VALID (SNP_POLICY_MASK_API_MINOR | \ SNP_POLICY_MASK_API_MAJOR | \ SNP_POLICY_MASK_SMT | \ SNP_POLICY_MASK_RSVD_MBO | \ @@ -2207,7 +2199,7 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) if (params.flags) return -EINVAL; - if (params.policy & ~SNP_POLICY_MASK_VALID) + if (params.policy & ~KVM_SNP_POLICY_MASK_VALID) return -EINVAL; /* Check for policy bits that must be set */ @@ -5085,10 +5077,10 @@ struct vmcb_save_area *sev_decrypt_vmsa(struct kvm_vcpu *vcpu) /* Check if the SEV policy allows debugging */ if (sev_snp_guest(vcpu->kvm)) { - if (!(sev->policy & SNP_POLICY_DEBUG)) + if (!(sev->policy & SNP_POLICY_MASK_DEBUG)) return NULL; } else { - if (sev->policy & SEV_POLICY_NODBG) + if (sev->policy & SEV_POLICY_MASK_NODBG) return NULL; } diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index e4b04f435b3d..379e14ad30e5 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -117,9 +117,6 @@ struct kvm_sev_info { cpumask_var_t have_run_cpus; /* CPUs that have done VMRUN for this VM. */ }; -#define SEV_POLICY_NODBG BIT_ULL(0) -#define SNP_POLICY_DEBUG BIT_ULL(19) - struct kvm_svm { struct kvm kvm; diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h index e0dbcb4b4fd9..27c92543bf38 100644 --- a/include/linux/psp-sev.h +++ b/include/linux/psp-sev.h @@ -14,6 +14,25 @@ #include +/* As defined by SEV API, under "Guest Policy". */ +#define SEV_POLICY_MASK_NODBG BIT(0) +#define SEV_POLICY_MASK_NOKS BIT(1) +#define SEV_POLICY_MASK_ES BIT(2) +#define SEV_POLICY_MASK_NOSEND BIT(3) +#define SEV_POLICY_MASK_DOMAIN BIT(4) +#define SEV_POLICY_MASK_SEV BIT(5) +#define SEV_POLICY_MASK_API_MAJOR GENMASK(23, 16) +#define SEV_POLICY_MASK_API_MINOR GENMASK(31, 24) + +/* As defined by SEV-SNP Firmware ABI, under "Guest Policy". */ +#define SNP_POLICY_MASK_API_MINOR GENMASK_ULL(7, 0) +#define SNP_POLICY_MASK_API_MAJOR GENMASK_ULL(15, 8) +#define SNP_POLICY_MASK_SMT BIT_ULL(16) +#define SNP_POLICY_MASK_RSVD_MBO BIT_ULL(17) +#define SNP_POLICY_MASK_MIGRATE_MA BIT_ULL(18) +#define SNP_POLICY_MASK_DEBUG BIT_ULL(19) +#define SNP_POLICY_MASK_SINGLE_SOCKET BIT_ULL(20) + #define SEV_FW_BLOB_MAX_SIZE 0x4000 /* 16KB */ /** -- 2.51.1 Supported policy bits are dependent on the level of SEV firmware that is currently running. Create an API to return the supported policy bits for the current level of firmware. Signed-off-by: Tom Lendacky --- drivers/crypto/ccp/sev-dev.c | 37 ++++++++++++++++++++++++++++++++++++ include/linux/psp-sev.h | 20 +++++++++++++++++++ 2 files changed, 57 insertions(+) diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 0d13d47c164b..db7c7c50cebc 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -2777,6 +2777,43 @@ void sev_platform_shutdown(void) } EXPORT_SYMBOL_GPL(sev_platform_shutdown); +u64 sev_get_snp_policy_bits(void) +{ + struct psp_device *psp = psp_master; + struct sev_device *sev; + u64 policy_bits; + + if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP)) + return 0; + + if (!psp || !psp->sev_data) + return 0; + + sev = psp->sev_data; + + policy_bits = SNP_POLICY_MASK_BASE; + + if (sev->snp_plat_status.feature_info) { + if (sev->snp_feat_info_0.ecx & SNP_RAPL_DISABLE_SUPPORTED) + policy_bits |= SNP_POLICY_MASK_RAPL_DIS; + + if (sev->snp_feat_info_0.ecx & SNP_CIPHER_TEXT_HIDING_SUPPORTED) + policy_bits |= SNP_POLICY_MASK_CIPHERTEXT_HIDING_DRAM; + + if (sev->snp_feat_info_0.ecx & SNP_AES_256_XTS_POLICY_SUPPORTED) + policy_bits |= SNP_POLICY_MASK_MEM_AES_256_XTS; + + if (sev->snp_feat_info_0.ecx & SNP_CXL_ALLOW_POLICY_SUPPORTED) + policy_bits |= SNP_POLICY_MASK_CXL_ALLOW; + + if (sev_version_greater_or_equal(1, 58)) + policy_bits |= SNP_POLICY_MASK_PAGE_SWAP_DISABLE; + } + + return policy_bits; +} +EXPORT_SYMBOL_GPL(sev_get_snp_policy_bits); + void sev_dev_destroy(struct psp_device *psp) { struct sev_device *sev = psp->sev_data; diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h index 27c92543bf38..1b4c68ec5c65 100644 --- a/include/linux/psp-sev.h +++ b/include/linux/psp-sev.h @@ -32,6 +32,20 @@ #define SNP_POLICY_MASK_MIGRATE_MA BIT_ULL(18) #define SNP_POLICY_MASK_DEBUG BIT_ULL(19) #define SNP_POLICY_MASK_SINGLE_SOCKET BIT_ULL(20) +#define SNP_POLICY_MASK_CXL_ALLOW BIT_ULL(21) +#define SNP_POLICY_MASK_MEM_AES_256_XTS BIT_ULL(22) +#define SNP_POLICY_MASK_RAPL_DIS BIT_ULL(23) +#define SNP_POLICY_MASK_CIPHERTEXT_HIDING_DRAM BIT_ULL(24) +#define SNP_POLICY_MASK_PAGE_SWAP_DISABLE BIT_ULL(25) + +/* Base SEV-SNP policy bitmask for minimum supported SEV firmware version */ +#define SNP_POLICY_MASK_BASE (SNP_POLICY_MASK_API_MINOR | \ + SNP_POLICY_MASK_API_MAJOR | \ + SNP_POLICY_MASK_SMT | \ + SNP_POLICY_MASK_RSVD_MBO | \ + SNP_POLICY_MASK_MIGRATE_MA | \ + SNP_POLICY_MASK_DEBUG | \ + SNP_POLICY_MASK_SINGLE_SOCKET) #define SEV_FW_BLOB_MAX_SIZE 0x4000 /* 16KB */ @@ -868,7 +882,10 @@ struct snp_feature_info { u32 edx; } __packed; +#define SNP_RAPL_DISABLE_SUPPORTED BIT(2) #define SNP_CIPHER_TEXT_HIDING_SUPPORTED BIT(3) +#define SNP_AES_256_XTS_POLICY_SUPPORTED BIT(4) +#define SNP_CXL_ALLOW_POLICY_SUPPORTED BIT(5) #ifdef CONFIG_CRYPTO_DEV_SP_PSP @@ -1014,6 +1031,7 @@ void *snp_alloc_firmware_page(gfp_t mask); void snp_free_firmware_page(void *addr); void sev_platform_shutdown(void); bool sev_is_snp_ciphertext_hiding_supported(void); +u64 sev_get_snp_policy_bits(void); #else /* !CONFIG_CRYPTO_DEV_SP_PSP */ @@ -1052,6 +1070,8 @@ static inline void sev_platform_shutdown(void) { } static inline bool sev_is_snp_ciphertext_hiding_supported(void) { return false; } +static inline u64 sev_get_snp_policy_bits(void) { return 0; } + #endif /* CONFIG_CRYPTO_DEV_SP_PSP */ #endif /* __PSP_SEV_H__ */ -- 2.51.1 Define the set of policy bits that KVM currently knows as not requiring any implementation support within KVM. Provide this value to userspace via the KVM_GET_DEVICE_ATTR ioctl. Signed-off-by: Tom Lendacky --- arch/x86/include/uapi/asm/kvm.h | 1 + arch/x86/kvm/svm/sev.c | 13 +++++++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h index d420c9c066d4..7ceff6583652 100644 --- a/arch/x86/include/uapi/asm/kvm.h +++ b/arch/x86/include/uapi/asm/kvm.h @@ -502,6 +502,7 @@ struct kvm_sync_regs { /* vendor-specific groups and attributes for system fd */ #define KVM_X86_GRP_SEV 1 # define KVM_X86_SEV_VMSA_FEATURES 0 +# define KVM_X86_SNP_POLICY_BITS 1 struct kvm_vmx_nested_state_data { __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index f04589ae76bb..a425674fe993 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -72,6 +72,8 @@ module_param_named(ciphertext_hiding_asids, nr_ciphertext_hiding_asids, uint, 04 SNP_POLICY_MASK_DEBUG | \ SNP_POLICY_MASK_SINGLE_SOCKET) +static u64 snp_supported_policy_bits __ro_after_init; + #define INITIAL_VMSA_GPA 0xFFFFFFFFF000 static u8 sev_enc_bit; @@ -2135,6 +2137,10 @@ int sev_dev_get_attr(u32 group, u64 attr, u64 *val) *val = sev_supported_vmsa_features; return 0; + case KVM_X86_SNP_POLICY_BITS: + *val = snp_supported_policy_bits; + return 0; + default: return -ENXIO; } @@ -2199,7 +2205,7 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) if (params.flags) return -EINVAL; - if (params.policy & ~KVM_SNP_POLICY_MASK_VALID) + if (params.policy & ~snp_supported_policy_bits) return -EINVAL; /* Check for policy bits that must be set */ @@ -3092,8 +3098,11 @@ void __init sev_hardware_setup(void) else if (sev_snp_supported) sev_snp_supported = is_sev_snp_initialized(); - if (sev_snp_supported) + if (sev_snp_supported) { + snp_supported_policy_bits = sev_get_snp_policy_bits() & + KVM_SNP_POLICY_MASK_VALID; nr_ciphertext_hiding_asids = init_args.max_snp_asid; + } /* * If ciphertext hiding is enabled, the joint SEV-ES/SEV-SNP -- 2.51.1 Add to the known supported SEV-SNP policy bits that don't require any implementation support from KVM in order to successfully use them. At this time, this includes: - CXL_ALLOW - MEM_AES_256_XTS - RAPL_DIS - CIPHERTEXT_HIDING_DRAM - PAGE_SWAP_DISABLE Arguably, RAPL_DIS and CIPHERTEXT_HIDING_DRAM require KVM and the CCP driver to enable these features in order for the setting of the policy bits to be successfully handled. But, a guest owner may not wish their guest to run on a system that doesn't provide support for those features, so allowing the specification of these bits accomplishes that. Whether or not the bit is supported by SEV firmware, a system that doesn't support these features will either fail during the KVM validation of supported policy bits before issuing the LAUNCH_START or fail during the LAUNCH_START. Signed-off-by: Tom Lendacky --- arch/x86/kvm/svm/sev.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index a425674fe993..f59c65abe3cf 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -65,12 +65,22 @@ module_param_named(ciphertext_hiding_asids, nr_ciphertext_hiding_asids, uint, 04 #define AP_RESET_HOLD_NAE_EVENT 1 #define AP_RESET_HOLD_MSR_PROTO 2 -#define KVM_SNP_POLICY_MASK_VALID (SNP_POLICY_MASK_API_MINOR | \ - SNP_POLICY_MASK_API_MAJOR | \ - SNP_POLICY_MASK_SMT | \ - SNP_POLICY_MASK_RSVD_MBO | \ - SNP_POLICY_MASK_DEBUG | \ - SNP_POLICY_MASK_SINGLE_SOCKET) +/* + * SEV-SNP policy bits that can be supported by KVM. These include policy bits + * that have implementation support within KVM or policy bits that do not + * require implementation support within KVM to enforce the policy. + */ +#define KVM_SNP_POLICY_MASK_VALID (SNP_POLICY_MASK_API_MINOR | \ + SNP_POLICY_MASK_API_MAJOR | \ + SNP_POLICY_MASK_SMT | \ + SNP_POLICY_MASK_RSVD_MBO | \ + SNP_POLICY_MASK_DEBUG | \ + SNP_POLICY_MASK_SINGLE_SOCKET | \ + SNP_POLICY_MASK_CXL_ALLOW | \ + SNP_POLICY_MASK_MEM_AES_256_XTS | \ + SNP_POLICY_MASK_RAPL_DIS | \ + SNP_POLICY_MASK_CIPHERTEXT_HIDING_DRAM | \ + SNP_POLICY_MASK_PAGE_SWAP_DISABLE) static u64 snp_supported_policy_bits __ro_after_init; -- 2.51.1