linux-kernel - Re: [PATCH v3 02/11] KVM: SVM: Change intercept

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Message-ID: <67dad5ee-1c70-b892-918a-8e7126aa4a5f@redhat.com>
Date:   Thu, 30 Jul 2020 01:08:10 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Babu Moger <babu.moger@....com>, Jim Mattson <jmattson@...gle.com>
Cc:     Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        kvm list <kvm@...r.kernel.org>, Joerg Roedel <joro@...tes.org>,
        the arch/x86 maintainers <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H . Peter Anvin" <hpa@...or.com>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH v3 02/11] KVM: SVM: Change intercept_cr to generic
 intercepts

On 29/07/20 18:08, Babu Moger wrote:
>>>
>>>         if (g->int_ctl & V_INTR_MASKING_MASK) {
>>>                 /* We only want the cr8 intercept bits of L1 */
>>> -               c->intercept_cr &= ~(1U << INTERCEPT_CR8_READ);
>>> -               c->intercept_cr &= ~(1U << INTERCEPT_CR8_WRITE);
>>> +               __clr_intercept(&c->intercepts, INTERCEPT_CR8_READ);
>>> +               __clr_intercept(&c->intercepts, INTERCEPT_CR8_WRITE);
>> Why the direct calls to the __clr_intercept worker function? Can't these be calls
>> to clr_cr_intercept()?
>> Likewise throughout.
> This code uses the address to clear the bits.  So called __clr_intercept
> directly. The call clr_cr_intercept() passes the structure vcpu_svm and
> then uses get_host_vmcb to get the address.

Yes, this is correct.

Paolo