linux-kernel - Re: [PATCH] KVM: nSVM: Drop redundant/wrong comment in nested_vmcb02_prepare

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Message-ID: <csyb3r77vfuzns7r4xfge7smxyw7vumdpjkntxctzkwu3cixib@dlo7kt7vgmcq>
Date: Tue, 13 Jan 2026 17:29:32 +0000
From: Yosry Ahmed <yosry.ahmed@...ux.dev>
To: Sean Christopherson <seanjc@...gle.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>, kvm@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] KVM: nSVM: Drop redundant/wrong comment in
 nested_vmcb02_prepare_save()

On Tue, Jan 13, 2026 at 05:28:07PM +0000, Yosry Ahmed wrote:
> The comment above DR6 and DR7 initializations is redundant, because the
> entire function follows the same pattern of only initializing the fields
> in vmcb02 if the vmcb12 changed or the fields are dirty, which handles
> the first execution case.
> 
> Also, the comment refers to new_vmcb12 as new_vmcs12. Just drop the
> comment.
> 
> No functional change intended.
> 
> Change-Id: Ib924765541fe3d8753b84b7ead8b47d8a24f0c8d

Lesson learned: no patch is too simple to run checkpatch.pl

> Signed-off-by: Yosry Ahmed <yosry.ahmed@...ux.dev>
> ---
>  arch/x86/kvm/svm/nested.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index f295a41ec659..cb00829896cc 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -699,7 +699,6 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12
>  	vmcb02->save.rsp = vmcb12->save.rsp;
>  	vmcb02->save.rip = vmcb12->save.rip;
>  
> -	/* These bits will be set properly on the first execution when new_vmc12 is true */
>  	if (unlikely(new_vmcb12 || vmcb_is_dirty(vmcb12, VMCB_DR))) {
>  		vmcb02->save.dr7 = svm->nested.save.dr7 | DR7_FIXED_1;
>  		svm->vcpu.arch.dr6  = svm->nested.save.dr6 | DR6_ACTIVE_LOW;
> 
> base-commit: f62b64b970570c92fe22503b0cdc65be7ce7fc7c
> -- 
> 2.52.0.457.g6b5491de43-goog
>