From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joerg Roedel <joro@8bytes.org>
Subject: Re: [RFC PATCH 00/62] Linux as SEV-ES Guest Support
Date: Tue, 11 Feb 2020 16:43:21 +0100
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To: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, hpa@zytor.com, Andy Lutomirski <luto@kernel.org>, Dave Hansen <dave.hansen@linux.intel.com>, Thomas Hellstrom <thellstrom@vmware.com>, Jiri Slaby <jslaby@suse.cz>, Dan Williams <dan.j.williams@intel.com>, Tom Lendacky <thomas.lendacky@amd.com>, Juergen Gross <jgross@suse.com>, Kees Cook <keescook@chromium.org>, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, Joerg Roedel <jroedel@suse.de>
List-Id: virtualization@lists.linuxfoundation.org

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