From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [PATCH 7/9] KVM: Expose the architectural performance monitoring CPUID leaf Date: Tue, 01 Nov 2011 09:49:27 -0600 Message-ID: <4EB01507.1020607@gmail.com> References: <1319993624-20247-1-git-send-email-gleb@redhat.com> <1319993624-20247-8-git-send-email-gleb@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, avi@redhat.com, mtosatti@redhat.com, linux-kernel@redhat.com, mingo@elte.hu, a.p.zijlstra@chello.nl, acme@ghostprotocols.net To: Gleb Natapov Return-path: Received: from mail-gx0-f174.google.com ([209.85.161.174]:37605 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752683Ab1KAPtd (ORCPT ); Tue, 1 Nov 2011 11:49:33 -0400 Received: by mail-gx0-f174.google.com with SMTP id b1so7167214ggn.19 for ; Tue, 01 Nov 2011 08:49:32 -0700 (PDT) In-Reply-To: <1319993624-20247-8-git-send-email-gleb@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 10/30/2011 10:53 AM, Gleb Natapov wrote: > From: Avi Kivity > > Provide a CPUID leaf that describes the emulated PMU. > > Signed-off-by: Avi Kivity > Signed-off-by: Gleb Natapov > --- > arch/x86/kvm/x86.c | 23 ++++++++++++++++++++++- > 1 files changed, 22 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 5ea4cb8..56153a9 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -2543,6 +2543,28 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > } > case 9: > break; > + case 0xa: { /* Architectural Performance Monitoring */ > + struct x86_pmu_capability cap; > + > + perf_get_x86_pmu_capability(&cap); > + > + /* > + * Only support guest architectural pmu on a host > + * with architectural pmu. > + */ > + if (!cap.version) > + memset(&cap, 0, sizeof(cap)); > + > + entry->eax = min(cap.version, 2) > + | (cap.num_counters_gp << 8) > + | (cap.bit_width_gp << 16) > + | (cap.events_mask_len << 24); > + entry->ebx = cap.events_mask; > + entry->ecx = 0; > + entry->edx = cap.num_counters_fixed > + | (cap.bit_width_fixed << 5); > + break; > + } If PERF_EVENTS is disabled in the host kernel will KVM return the right thing for the guest that might have PERF_EVENTS enabled? David > /* function 0xb has additional index. */ > case 0xb: { > int i, level_type; > @@ -2637,7 +2659,6 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > case 3: /* Processor serial number */ > case 5: /* MONITOR/MWAIT */ > case 6: /* Thermal management */ > - case 0xA: /* Architectural Performance Monitoring */ > case 0x80000007: /* Advanced power management */ > case 0xC0000002: > case 0xC0000003: