From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 7/9] KVM: Expose the architectural performance monitoring CPUID leaf Date: Tue, 01 Nov 2011 12:51:53 +0200 Message-ID: <4EAFCF49.2070508@redhat.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, mtosatti@redhat.com, mingo@elte.hu, a.p.zijlstra@chello.nl, acme@ghostprotocols.net To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:2502 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753005Ab1KAKwL (ORCPT ); Tue, 1 Nov 2011 06:52:11 -0400 In-Reply-To: <1319993624-20247-8-git-send-email-gleb@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 10/30/2011 06:53 PM, 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); What if num_counters_gp is larger than our array? > + entry->ebx = cap.events_mask; > + entry->ecx = 0; > + entry->edx = cap.num_counters_fixed > + | (cap.bit_width_fixed << 5); Ditto. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.