From: Andrew Jones <drjones@redhat.com>
To: Wei Huang <wei@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
pbonzini@redhat.com, gleb@kernel.org, tglx@linutronix.de,
mingo@redhat.com, hpa@zytor.com, x86@kernel.org, joro@8bytes.org,
trivial@kernel.org
Subject: Re: [KVM x86 vPMU Patch 2/2] KVM: x86/vPMU: Fix unnecessary signed extension for AMD PERFCTRn
Date: Tue, 11 Aug 2015 09:33:18 +0200 [thread overview]
Message-ID: <20150811073318.GE4441@hawk.localdomain> (raw)
In-Reply-To: <1438977210-24787-3-git-send-email-wei@redhat.com>
On Fri, Aug 07, 2015 at 03:53:30PM -0400, Wei Huang wrote:
> According to AMD programmer's manual, AMD PERFCTRn is 64-bit MSR which,
> unlike Intel perf counters, doesn't require signed extension. This
> patch removes the unnecessary conversion in SVM vPMU code when PERFCTRn
> is being updated.
>
> Signed-off-by: Wei Huang <wei@redhat.com>
> ---
> arch/x86/kvm/pmu_amd.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/arch/x86/kvm/pmu_amd.c b/arch/x86/kvm/pmu_amd.c
> index 886aa25..39b9112 100644
> --- a/arch/x86/kvm/pmu_amd.c
> +++ b/arch/x86/kvm/pmu_amd.c
> @@ -133,8 +133,6 @@ static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
> /* MSR_K7_PERFCTRn */
> pmc = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0);
> if (pmc) {
> - if (!msr_info->host_initiated)
> - data = (s64)data;
> pmc->counter += data - pmc_read_counter(pmc);
> return 0;
> }
> --
> 1.8.3.1
Reviewed-by: Andrew Jones <drjones@redhat.com>
next prev parent reply other threads:[~2015-08-11 7:33 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-07 19:53 [KVM x86 vPMU Patch 0/2] Two vPMU Trivial Patches Wei Huang
2015-08-07 19:53 ` [KVM x86 vPMU Patch 1/2] KVM: x86/vPMU: Move the definition of kvm_pmu_ops to arch-specific files Wei Huang
2015-08-11 7:32 ` Andrew Jones
2015-08-07 19:53 ` [KVM x86 vPMU Patch 2/2] KVM: x86/vPMU: Fix unnecessary signed extension for AMD PERFCTRn Wei Huang
2015-08-11 7:33 ` Andrew Jones [this message]
2015-08-11 13:21 ` [KVM x86 vPMU Patch 0/2] Two vPMU Trivial Patches Paolo Bonzini
2015-08-11 14:52 ` Wei Huang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150811073318.GE4441@hawk.localdomain \
--to=drjones@redhat.com \
--cc=gleb@kernel.org \
--cc=hpa@zytor.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=tglx@linutronix.de \
--cc=trivial@kernel.org \
--cc=wei@redhat.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox