linux-kernel - Re: [PATCH 8/8] KVM: x86: SVM: remove vgif

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Message-ID: <00fbd38e-2a9c-fda2-2565-6a53940b43e6@redhat.com>
Date:   Wed, 30 Mar 2022 14:08:56 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Maxim Levitsky <mlevitsk@...hat.com>
Cc:     kvm@...r.kernel.org, Jim Mattson <jmattson@...gle.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Borislav Petkov <bp@...en8.de>, Joerg Roedel <joro@...tes.org>,
        Ingo Molnar <mingo@...hat.com>,
        Suravee Suthikulpanit <suravee.suthikulpanit@....com>,
        x86@...nel.org, "H. Peter Anvin" <hpa@...or.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        linux-kernel@...r.kernel.org,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH 8/8] KVM: x86: SVM: remove vgif_enabled()

On 3/30/22 02:20, Sean Christopherson wrote:
> It'd be helpful to explicitly call out that KVM always takes V_GIF_ENABLE_MASK
> from vmcs01, otherwise this looks like it does unintentend things when KVM is
> runing vmcb02.

I will add a note to the commit message.

More precisely, because KVM does not (as of this patch) support vGIF 
when L1 runs L2, the vmcb02's V_GIF_MASK and V_GIF_ENABLE_MASK also 
control L1's GIF and are the same as vmcs01's.

Paolo