Reject COPY_ENC_CONTEXT_FROM if the destination VM has created vCPUs.
KVM relies on SEV activation to occur before vCPUs are created, e.g. to
set VMCB flags and intercepts correctly.
Fixes: 54526d1fd593 ("KVM: x86: Support KVM VMs sharing SEV context")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Peter Gonda <pgonda@xxxxxxxxxx>
Cc: Marc Orr <marcorr@xxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Nathan Tempelman <natet@xxxxxxxxxx>
Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/svm/sev.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 3e2769855e51..eeec499e4372 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1775,7 +1775,12 @@ int svm_vm_copy_asid_from(struct kvm *kvm, unsigned int source_fd)
mutex_unlock(&source_kvm->lock);
mutex_lock(&kvm->lock);
- if (sev_guest(kvm)) {
+ /*
+ * Disallow out-of-band SEV/SEV-ES init if the target is already an
+ * SEV guest, or if vCPUs have been created. KVM relies on vCPUs being
+ * created after SEV/SEV-ES initialization, e.g. to init intercepts.
+ */
+ if (sev_guest(kvm) || kvm->created_vcpus) {
ret = -EINVAL;
goto e_mirror_unlock;
}
--
2.34.0.rc0.344.g81b53c2807-goog
