linux-kernel - Re: [PATCH 10/21] KVM: SEV: Use a VMSA physical address variable for populating VMCB

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Message-ID: <Zd6T06Qghvutp8Qw@google.com>
Date: Tue, 27 Feb 2024 18:00:51 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Paolo Bonzini <pbonzini@...hat.com>
Cc: linux-kernel@...r.kernel.org, kvm@...r.kernel.org, michael.roth@....com, 
	isaku.yamahata@...el.com, thomas.lendacky@....com, 
	Ashish Kalra <ashish.kalra@....com>
Subject: Re: [PATCH 10/21] KVM: SEV: Use a VMSA physical address variable for
 populating VMCB

On Tue, Feb 27, 2024, Paolo Bonzini wrote:
> From: Tom Lendacky <thomas.lendacky@....com>
> 
> In preparation to support SEV-SNP AP Creation, use a variable that holds
> the VMSA physical address rather than converting the virtual address.
> This will allow SEV-SNP AP Creation to set the new physical address that
> will be used should the vCPU reset path be taken.

No, this patch belongs in the SNP series.  The hanlding of vmsa_pa is broken
(KVM leaks the page set by the guest; I need to follow-up in the SNP series).
On top of that, I detest duplicat variables, and I don't like that KVM keeps its
original VMSA (kernel allocation) after the guest creates its own.

I can't possibly imagine why this needs to be pulled in early.  There's no way
TDX needs this, and while this patch is _small_, the functional change it leads
to is not.