From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Huang 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 Message-ID: <1438977210-24787-3-git-send-email-wei@redhat.com> References: <1438977210-24787-1-git-send-email-wei@redhat.com> 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 To: kvm@vger.kernel.org Return-path: In-Reply-To: <1438977210-24787-1-git-send-email-wei@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org 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 --- 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