Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] KVM: x86: Fix perfctr WRMSR for running counters
To:     Eric Hankland <ehankland@google.com>
Cc:     Jim Mattson <jmattson@google.com>, Peter Shier <pshier@google.com>,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org
References: <20200127212256.194310-1-ehankland@google.com>
 <2a394c6d-c453-6559-bf33-f654af7922bd@redhat.com>
 <CAOyeoRVaV3Dh=M4ioiT3DU+p5ZnQGRcy9_PssJZ=a36MhL-xHQ@mail.gmail.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <c1cec3c8-570f-d824-cb20-6641cf686981@redhat.com>
Date:   Sat, 1 Feb 2020 19:51:40 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.1.1
MIME-Version: 1.0
In-Reply-To: <CAOyeoRVaV3Dh=M4ioiT3DU+p5ZnQGRcy9_PssJZ=a36MhL-xHQ@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 30/01/20 02:09, Eric Hankland wrote:
> Sorry - I forgot to switch to plain text mode on my first reply.
> 
>> I think this best written as it was before commit 2924b52117:
>>
>>                         if (!msr_info->host_initiated)
>>                                 data = (s64)(s32)data;
>>                         pmc->counter += data - pmc_read_counter(pmc);
> Sounds good to me.
> 
>> Do you have a testcase?
> I added a testcase to kvm-unit-tests/x86/pmu.c that fails without this
> patch and passes with it. Should I send out that patch now?

Yes, please send it!  Thanks,

Paolo