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From:   Jim Mattson <jmattson@google.com>
Date:   Wed, 29 Jul 2020 14:23:35 -0700
Message-ID: <CALMp9eQUNLXgveya3TpyCH7L8EbEUEdPy+_ee_wSXwxqsKPDwQ@mail.gmail.com>
Subject: Re: [PATCH v3 06/11] KVM: SVM: Add new intercept vector in vmcb_control_area
To:     Babu Moger <babu.moger@amd.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        kvm list <kvm@vger.kernel.org>, Joerg Roedel <joro@8bytes.org>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H . Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>
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On Tue, Jul 28, 2020 at 4:38 PM Babu Moger <babu.moger@amd.com> wrote:
>
> The new intercept bits have been added in vmcb control area to support
> few more interceptions. Here are the some of them.
>  - INTERCEPT_INVLPGB,
>  - INTERCEPT_INVLPGB_ILLEGAL,
>  - INTERCEPT_INVPCID,
>  - INTERCEPT_MCOMMIT,
>  - INTERCEPT_TLBSYNC,
>
> Add new intercept vector in vmcb_control_area to support these instructio=
ns.
> Also update kvm_nested_vmrun trace function to support the new addition.
>
> AMD documentation for these instructions is available at "AMD64
> Architecture Programmer=E2=80=99s Manual Volume 2: System Programming, Pu=
b. 24593
> Rev. 3.34(or later)"
>
> The documentation can be obtained at the links below:
> Link: https://www.amd.com/system/files/TechDocs/24593.pdf
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=3D206537
>
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> ---

> @@ -16,6 +16,7 @@ enum vector_offset {
>         EXCEPTION_VECTOR,
>         INTERCEPT_VECTOR_3,
>         INTERCEPT_VECTOR_4,
> +       INTERCEPT_VECTOR_5,
>         MAX_VECTORS,
>  };

Is this enumeration actually adding any value?
vmcb->control.intercepts[INTERCEPT_VECTOR_5] doesn't seem in any way
"better" than just vmcb->control.intercepts[5].

Reviewed-by: Jim Mattson <jmattson@google.com>