From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH] pmu: prepare for migration support Date: Tue, 2 Apr 2013 17:43:00 +0300 Message-ID: <20130402144300.GG3889@redhat.com> References: <1364487515-6454-1-git-send-email-pbonzini@redhat.com> <1364487515-6454-2-git-send-email-pbonzini@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: Paolo Bonzini Return-path: Received: from mx1.redhat.com ([209.132.183.28]:32054 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759790Ab3DBOnC (ORCPT ); Tue, 2 Apr 2013 10:43:02 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r32Eh2nx032303 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 2 Apr 2013 10:43:02 -0400 Content-Disposition: inline In-Reply-To: <1364487515-6454-2-git-send-email-pbonzini@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Mar 28, 2013 at 05:18:35PM +0100, Paolo Bonzini wrote: > In order to migrate the PMU state correctly, we need to restore the > values of MSR_CORE_PERF_GLOBAL_STATUS (a read-only register) and > MSR_CORE_PERF_GLOBAL_OVF_CTRL (which has side effects when written). > We also need to write the full 40-bit value of the performance counter, > > which would only be possible with a v3 architectural PMU's > > full-width counter MSRs. > > > > To distinguish host-initiated writes from the guest's, pass the > > full struct msr_data to kvm_pmu_set_msr. > > Signed-off-by: Paolo Bonzini Applied, thanks. > --- > arch/x86/include/asm/kvm_host.h | 2 +- > arch/x86/kvm/pmu.c | 14 +++++++++++--- > arch/x86/kvm/x86.c | 4 ++-- > 3 files changed, 14 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 36fba01..e2e09f3 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1029,7 +1029,7 @@ void kvm_pmu_reset(struct kvm_vcpu *vcpu); > void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu); > bool kvm_pmu_msr(struct kvm_vcpu *vcpu, u32 msr); > int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data); > -int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data); > +int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info); > int kvm_pmu_read_pmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data); > void kvm_handle_pmu_event(struct kvm_vcpu *vcpu); > void kvm_deliver_pmi(struct kvm_vcpu *vcpu); > diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c > index cfc258a..c53e797 100644 > --- a/arch/x86/kvm/pmu.c > +++ b/arch/x86/kvm/pmu.c > @@ -360,10 +360,12 @@ int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data) > return 1; > } > > -int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data) > +int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > { > struct kvm_pmu *pmu = &vcpu->arch.pmu; > struct kvm_pmc *pmc; > + u32 index = msr_info->index; > + u64 data = msr_info->data; > > switch (index) { > case MSR_CORE_PERF_FIXED_CTR_CTRL: > @@ -375,6 +377,10 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data) > } > break; > case MSR_CORE_PERF_GLOBAL_STATUS: > + if (msr_info->host_initiated) { > + pmu->global_status = data; > + return 0; > + } > break; /* RO MSR */ > case MSR_CORE_PERF_GLOBAL_CTRL: > if (pmu->global_ctrl == data) > @@ -386,7 +392,8 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data) > break; > case MSR_CORE_PERF_GLOBAL_OVF_CTRL: > if (!(data & (pmu->global_ctrl_mask & ~(3ull<<62)))) { > - pmu->global_status &= ~data; > + if (!msr_info->host_initiated) > + pmu->global_status &= ~data; > pmu->global_ovf_ctrl = data; > return 0; > } > @@ -394,7 +401,8 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data) > default: > if ((pmc = get_gp_pmc(pmu, index, MSR_IA32_PERFCTR0)) || > (pmc = get_fixed_pmc(pmu, index))) { > - data = (s64)(s32)data; > + if (!msr_info->host_initiated) > + data = (s64)(s32)data; > pmc->counter += data - read_pmc(pmc); > return 0; > } else if ((pmc = get_gp_pmc(pmu, index, MSR_P6_EVNTSEL0))) { > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 3e0a8ba..1d928af 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -2042,7 +2042,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > case MSR_P6_EVNTSEL0: > case MSR_P6_EVNTSEL1: > if (kvm_pmu_msr(vcpu, msr)) > - return kvm_pmu_set_msr(vcpu, msr, data); > + return kvm_pmu_set_msr(vcpu, msr_info); > > if (pr || data != 0) > vcpu_unimpl(vcpu, "disabled perfctr wrmsr: " > @@ -2088,7 +2088,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > if (msr && (msr == vcpu->kvm->arch.xen_hvm_config.msr)) > return xen_hvm_config(vcpu, data); > if (kvm_pmu_msr(vcpu, msr)) > - return kvm_pmu_set_msr(vcpu, msr, data); > + return kvm_pmu_set_msr(vcpu, msr_info); > if (!ignore_msrs) { > vcpu_unimpl(vcpu, "unhandled wrmsr: 0x%x data %llx\n", > msr, data); > -- > 1.8.1.4 -- Gleb.