From: Wei Huang <wei@redhat.com>
To: kvm@vger.kernel.org
Cc: 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, drjones@redhat.com
Subject: [KVM x86 vPMU Patch 2/2] KVM: x86/vPMU: Fix unnecessary signed extension for AMD PERFCTRn
Date: Fri, 7 Aug 2015 15:53:30 -0400 [thread overview]
Message-ID: <1438977210-24787-3-git-send-email-wei@redhat.com> (raw)
In-Reply-To: <1438977210-24787-1-git-send-email-wei@redhat.com>
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
next prev parent reply other threads:[~2015-08-07 19:53 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 ` Wei Huang [this message]
2015-08-11 7:33 ` [KVM x86 vPMU Patch 2/2] KVM: x86/vPMU: Fix unnecessary signed extension for AMD PERFCTRn Andrew Jones
2015-08-11 13:21 ` [KVM x86 vPMU Patch 0/2] Two vPMU Trivial Patches Paolo Bonzini
2015-08-11 14:52 ` Wei Huang
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