Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <7f3842a2-879b-2460-229e-745b7122b36a@gmail.com>
Date:   Mon, 29 May 2023 22:36:39 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0)
 Gecko/20100101 Thunderbird/102.11.0
Subject: Re: [PATCH 5/5] KVM: x86/pmu: Hide guest counter updates from the
 VMRUN instruction
Content-Language: en-US
To:     Jim Mattson <jmattson@google.com>,
        Sean Christopherson <seanjc@google.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Ravi Bangoria <ravi.bangoria@amd.com>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230310105346.12302-1-likexu@tencent.com>
 <20230310105346.12302-6-likexu@tencent.com> <ZG6AUjci2J9WpT2z@google.com>
 <CALMp9eSe+kx8s5rkypvHWjFr45L_foXiDi1Vdp3R=AmRwA3RAQ@mail.gmail.com>
From:   Like Xu <like.xu.linux@gmail.com>
In-Reply-To: <CALMp9eSe+kx8s5rkypvHWjFr45L_foXiDi1Vdp3R=AmRwA3RAQ@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 25/5/2023 5:30 am, Jim Mattson wrote:
> Note that there's a bug in the original code for this that has
> probably never been fixed: it ignores CMASK and INV in the PerfEvtSel.

Regarding the emulation of CMASK, INV and PIN_CONTROL bits on vPMU,
please forgive me for never having the right expectations (so there will be no
correct emulation), an share more *architecture* descriptions of those hw
behavior, and it would be great to have corresponding selftests as a bug report.