On Tue, Feb 11, 2020 at 03:50:08PM +0100, Peter Zijlstra wrote:
 

Oh gawd; so instead of improving the whole NMI situation, AMD went and
made it worse still ?!?

Well, depends on how you want to see it. Under SEV-ES an IRET will not
re-open the NMI window, but the guest has to tell the hypervisor
explicitly when it is ready to receive new NMIs via the NMI_COMPLETE
message.  NMIs stay blocked even when an exception happens in the
handler, so this could also be seen as a (slight) improvement.

Regards,

	Joerg