diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2025-10-27 14:33:51 -0500 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2025-11-14 10:30:12 -0800 |
| commit | 7a61d61396b97fd6bb9b9bde321c68513034ad11 (patch) | |
| tree | ff251d5f2f76059fe57ff64995c471268015ea5a | |
| parent | c9434e64e8b4d17511f514f7495008f573595e3e (diff) | |
KVM: SEV: Publish supported SEV-SNP policy bits
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 <thomas.lendacky@amd.com>
Link: https://patch.msgid.link/c596f7529518f3f826a57970029451d9385949e5.1761593632.git.thomas.lendacky@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/include/uapi/asm/kvm.h | 1 | ||||
| -rw-r--r-- | 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 @@ out: 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 |