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Date: Wed, 17 Jun 2026 16:44:54 +0200
From: =?utf-8?B?SsO2cmcgUsO2ZGVs?= <joro@8bytes.org>
To: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>, x86@kernel.org, 
	Tom Lendacky <thomas.lendacky@amd.com>, Michael Roth <michael.roth@amd.com>, kvm@vger.kernel.org, 
	linux-kernel@vger.kernel.org, coconut-svsm@lists.linux.dev, 
	Joerg Roedel <joerg.roedel@amd.com>, Jethro Beekman <jethro@fortanix.com>
Subject: Re: [PATCH 4/4] kvm: svm: Support KVM_SEV_SNP_PAGE_TYPE_VMSA at
 SNP_LAUNCH_UPDATE
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On Wed, Jun 17, 2026 at 06:37:52AM -0700, Sean Christopherson wrote:
> Ok, so it took us a few times to learn our lesson.  I still don't see that as a
> strong argument for new uAPI, especially not for VMSA pages.  I am very firmly
> of the opinion that letting anything but the host kernel configure the VMSA is
> beyond stupid, but unfortunately we're stuck with AP_CREATION.  Expanding that
> surface has a very, very, VERY high bar to get over.

The strongest argument in my view (and the main reason we are doing this) is
actually the predictable launch measurement. On SEV-SNP this is a requirement
to use platform VM-identity features like the ID Block.

-Joerg