From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Wang Subject: Re: [PATCH v3 3/5] KVM/x86: expose MSR_IA32_PERF_CAPABILITIES to the guest Date: Thu, 20 Sep 2018 20:38:20 +0800 Message-ID: <5BA394BC.1070804@intel.com> References: <1537437959-8751-1-git-send-email-wei.w.wang@intel.com> <1537437959-8751-4-git-send-email-wei.w.wang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: kan.liang@intel.com, peterz@infradead.org, mingo@redhat.com, rkrcmar@redhat.com, like.xu@intel.com, jannh@google.com, arei.gonglei@huawei.com To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, pbonzini@redhat.com, ak@linux.intel.com Return-path: In-Reply-To: <1537437959-8751-4-git-send-email-wei.w.wang@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 09/20/2018 06:05 PM, Wei Wang wrote: > Bits [0, 5] of MSR_IA32_PERF_CAPABILITIES tell about the format of > the addresses stored in the LBR stack. Expose those bits to the guest > when the guest lbr feature is enabled. > > Signed-off-by: Like Xu > Signed-off-by: Wei Wang > Cc: Paolo Bonzini > Cc: Andi Kleen > --- > arch/x86/include/asm/perf_event.h | 2 ++ > arch/x86/kvm/cpuid.c | 2 +- > arch/x86/kvm/vmx.c | 7 +++++++ > 3 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h > index 84cc8cb..e893a69 100644 > --- a/arch/x86/include/asm/perf_event.h > +++ b/arch/x86/include/asm/perf_event.h > @@ -79,6 +79,8 @@ > #define ARCH_PERFMON_BRANCH_MISSES_RETIRED 6 > #define ARCH_PERFMON_EVENTS_COUNT 7 > > +#define PERF_CAP_MASK_LBR_FMT 0x3f > + > /* > * Intel "Architectural Performance Monitoring" CPUID > * detection/enumeration details: > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 7bcfa61..3b8a57b 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -365,7 +365,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | > 0 /* DS-CPL, VMX, SMX, EST */ | > 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | > - F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | > + F(FMA) | F(CX16) | 0 /* xTPR Update*/ | F(PDCM) | > F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | > F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | > 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 533a327..92705b5 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -4134,6 +4134,13 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP)) > return 1; > /* Otherwise falls through */ > + case MSR_IA32_PERF_CAPABILITIES: > + if (!boot_cpu_has(X86_FEATURE_PDCM)) > + return 1; > + msr_info->data = native_read_msr(MSR_IA32_PERF_CAPABILITIES); > + if (vcpu->kvm->arch.guest_lbr_enabled) > + msr_info->data &= PERF_CAP_MASK_LBR_FMT; > + break; Sorry about a mistake here. Will move "case MSR_IA32_PERF_CAPABILITIES" one step above - above "case TSC_AUX". Best, Wei