KVM/SVM: add support for SEV attestation command

The SEV FW version >= 0.23 added a new command that can be used to query
the attestation report containing the SHA-256 digest of the guest memory
encrypted through the KVM_SEV_LAUNCH_UPDATE_{DATA, VMSA} commands and
sign the report with the Platform Endorsement Key (PEK).

See the SEV FW API spec section 6.8 for more details.

Note there already exist a command (KVM_SEV_LAUNCH_MEASURE) that can be
used to get the SHA-256 digest. The main difference between the
KVM_SEV_LAUNCH_MEASURE and KVM_SEV_ATTESTATION_REPORT is that the latter
can be called while the guest is running and the measurement value is
signed with PEK.

Cc: James Bottomley <[email protected]>
Cc: Tom Lendacky <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: John Allen <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: [email protected]
Reviewed-by: Tom Lendacky <[email protected]>
Acked-by: David Rientjes <[email protected]>
Tested-by: James Bottomley <[email protected]>
Signed-off-by: Brijesh Singh <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 374c67875cdb..07c194e2c302 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1593,6 +1593,8 @@ enum sev_cmd_id {
 	KVM_SEV_DBG_ENCRYPT,
 	/* Guest certificates commands */
 	KVM_SEV_CERT_EXPORT,
+	/* Attestation report */
+	KVM_SEV_GET_ATTESTATION_REPORT,
 
 	KVM_SEV_NR_MAX,
 };
@@ -1645,6 +1647,12 @@ struct kvm_sev_dbg {
 	__u32 len;
 };
 
+struct kvm_sev_attestation_report {
+	__u8 mnonce[16];
+	__u64 uaddr;
+	__u32 len;
+};
+
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
 #define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)
 #define KVM_DEV_ASSIGN_MASK_INTX	(1 << 2)