On Tue, Sep 14, 2021, Peter Gonda wrote: > Copying an ASID into new vCPUs will not work for SEV-ES since the vCPUs > VMSAs need to be setup and measured before SEV_LAUNCH_FINISH. Return an > error if a users tries to KVM_CAP_VM_COPY_ENC_CONTEXT_FROM from an > SEV-ES guest. What happens if userspace does KVM_CAP_VM_COPY_ENC_CONTEXT_FROM before the source has created vCPUs, i.e. before it has done SEV_LAUNCH_FINISH? Might be worth noting that the destination cannot be an SEV guest, and therefore can't be an SEV-ES guest either. > Fixes: 54526d1fd593 ("KVM: x86: Support KVM VMs sharing SEV context") Cc: stable@xxxxxxxxxxxxxxx