On 11/16/20 12:09 PM, Paolo Bonzini wrote: > On 16/11/20 18:02, Tom Lendacky wrote: >> From: Tom Lendacky<thomas.lendacky@xxxxxxx> >> >> Currently, the nested state format is hardcoded to VMX. This will result >> in kvm_put_nested_state() returning an error because the KVM SVM support >> checks for the nested state to be KVM_STATE_NESTED_FORMAT_SVM. As a >> result, kvm_arch_put_registers() errors out early. >> >> Update the setting of the format based on the virtualization feature: >> VMX - KVM_STATE_NESTED_FORMAT_VMX >> SVM - KVM_STATE_NESTED_FORMAT_SVM > > Looks good, but what are the symptoms of this in practice? I discovered this while testing my SEV-ES patches. When I specified the '+svm' feature, the new SEV-ES reset address for the APs wasn't getting set because kvm_arch_put_registers() erred out before it could call kvm_getput_regs(). This resulted in the guest crashing when OVMF tried to start the APs. For a non-SEV-ES guest, I'm not sure if other updates could be missed, potentially. Thanks, Tom > > Paolo >
