[PATCH 1/2] KVM: SEV: Do not allow SEV-SNP VMs from intra-host migration

[Atish Patra]

From: Atish Patra <atishp@xxxxxxxx>

The intra-host migration feature is not fully implemented for SEV-SNP
VMs which require additional SNP-specific state such as guest_req_mutex,
guest_req_buf, and guest_resp_buf to be transferred or initialized on
the destination.

Reject SNP source VMs in sev_vm_move_enc_context_from() until proper
SNP state transfer is implemented.

Fixes: 0b020f5af092 ("KVM: SEV: Add support for SEV-ES intra host migration")

Reported-by: Chris Mason <clm@xxxxxxxx>
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Atish Patra <atishp@xxxxxxxx>
---
 arch/x86/kvm/svm/sev.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index c2126b3c3072..aff6a0cf5bfe 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2142,7 +2142,8 @@ int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd)
 		return ret;
 
 	if (kvm->arch.vm_type != source_kvm->arch.vm_type ||
-	    sev_guest(kvm) || !sev_guest(source_kvm)) {
+	    sev_guest(kvm) || !sev_guest(source_kvm) ||
+	    sev_snp_guest(source_kvm)) {
 		ret = -EINVAL;
 		goto out_unlock;
 	}

-- 
2.53.0-Meta