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@xxxxxxx>
---
arch/x86/include/uapi/asm/kvm.h | 1 +
arch/x86/kvm/svm/sev.c | 11 ++++++++++-
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 0f15d683817d..90e9c4551fa6 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -468,6 +468,7 @@ 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 2fbdebf79fbb..7e6ce092628a 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -78,6 +78,8 @@ static u64 sev_supported_vmsa_features;
SNP_POLICY_MASK_DEBUG | \
SNP_POLICY_MASK_SINGLE_SOCKET)
+static u64 snp_supported_policy_bits;
+
#define INITIAL_VMSA_GPA 0xFFFFFFFFF000
static u8 sev_enc_bit;
@@ -2113,6 +2115,10 @@ 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;
}
@@ -2177,7 +2183,7 @@ 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 & ~snp_supported_policy_bits)
return -EINVAL;
/* Check for policy bits that must be set */
@@ -3054,6 +3060,9 @@ void __init sev_hardware_setup(void)
sev_supported = sev_es_supported = sev_snp_supported = false;
else if (sev_snp_supported)
sev_snp_supported = is_sev_snp_initialized();
+
+ if (sev_snp_supported)
+ snp_supported_policy_bits = SNP_POLICY_MASK_VALID;
}
if (boot_cpu_has(X86_FEATURE_SEV))
--
2.46.2
