From: Brijesh Singh <brijesh.singh@amd.com>

The KVM_SEV_SNP_LAUNCH_FINISH finalize the cryptographic digest and stores
it as the measurement of the guest at launch.

While finalizing the launch flow, it also issues the LAUNCH_UPDATE command
to encrypt the VMSA pages.

If its an SNP guest, then VMSA was added in the RMP entry as
a guest owned page and also removed from the kernel direct map
so flush it later after it is transitioned back to hypervisor
state and restored in the direct map.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Harald Hoyer <harald@profian.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
 .../virt/kvm/x86/amd-memory-encryption.rst    |  23 ++++
 arch/x86/kvm/svm/sev.c                        | 122 ++++++++++++++++++
 include/uapi/linux/kvm.h                      |  14 ++
 3 files changed, 159 insertions(+)

[...]

+#define KVM_SEV_SNP_ID_BLOCK_SIZE      96
+#define KVM_SEV_SNP_ID_AUTH_SIZE       4096
+#define KVM_SEV_SNP_FINISH_DATA_SIZE   32
+
+struct kvm_sev_snp_launch_finish {
+       __u64 id_block_uaddr;
+       __u64 id_auth_uaddr;
+       __u8 id_block_en;
+       __u8 auth_key_en;
+       __u8 host_data[KVM_SEV_SNP_FINISH_DATA_SIZE];
+       __u8 pad[6];

The LAUNCH_FINISH command received a new argument to disable VCEK (VCEK_DIS). Shouldn't we add that in this patch already?


Alex