linux-kernel - Re: [PATCH v2 2/4] KVM: VMX: Handle #MCs on VM-Enter/TD-Enter outside of the fastpath

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Message-ID: <aSC2czXKanvvtcLJ@google.com>
Date: Fri, 21 Nov 2025 10:58:59 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Binbin Wu <binbin.wu@...ux.intel.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>, "Kirill A. Shutemov" <kas@...nel.org>, kvm@...r.kernel.org, 
	x86@...nel.org, linux-coco@...ts.linux.dev, linux-kernel@...r.kernel.org, 
	Rick Edgecombe <rick.p.edgecombe@...el.com>, Jon Kohler <jon@...anix.com>, 
	Tony Lindgren <tony.lindgren@...ux.intel.com>
Subject: Re: [PATCH v2 2/4] KVM: VMX: Handle #MCs on VM-Enter/TD-Enter outside
 of the fastpath

On Fri, Nov 21, 2025, Binbin Wu wrote:
> On 11/19/2025 6:23 AM, Sean Christopherson wrote:
> > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> > index fdcc519348cd..f369c499b2c3 100644
> > --- a/arch/x86/kvm/vmx/vmx.c
> > +++ b/arch/x86/kvm/vmx/vmx.c
> > @@ -7062,10 +7062,19 @@ void vmx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
> 
> I think the bug in v1 is because the fact that the function is the common path
> for both VMX and TDX is overlooked. Do you think it is worth a comment to
> tell the function is the common path for both VMX and TDX?

Probably not?  Addressing that quirk crossed my mind as well, but there are so
many dependencies and so much interaction between VMX and TDX code that I think
we just need get used to things and not assuming TDX is isolated.  I.e. trying
to add comments and/or tweak names will probably be a game of whack-a-mole, and
will likely cause confusion, e.g. due to some flows being commented and others
not.