From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9E01ECAAD5 for ; Mon, 5 Sep 2022 17:37:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237446AbiIERhF (ORCPT ); Mon, 5 Sep 2022 13:37:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230035AbiIERhD (ORCPT ); Mon, 5 Sep 2022 13:37:03 -0400 Received: from mail-oa1-x2c.google.com (mail-oa1-x2c.google.com [IPv6:2001:4860:4864:20::2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED8B25E668 for ; Mon, 5 Sep 2022 10:37:02 -0700 (PDT) Received: by mail-oa1-x2c.google.com with SMTP id 586e51a60fabf-1279948d93dso3015152fac.10 for ; Mon, 05 Sep 2022 10:37:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date; bh=a1Wl5OOBM+OdiCqwjpRNbQVvWBi9SOkRJQ7j+gqJGAI=; b=omXxCPqBgDlAxdUX5U3YmgblCVqUcKpbsoTO+4DUk94Iq8Ti9QLdiueFbqZ+DgSlp1 V8iuStpxP2j4Ww3tI5mVwdlgs1zcuRT7t7INHg1D0a7/IAnd9sXOCdqgra40rPUE8wD0 cg4U3zqiRno6i+kIK7wfyr0jwxRhlU3xtFU/jTVDRYdedLsMRBHOcbn1RUKJY2Unmeeb 4iCsdLOAZ4xhRkAWzbOtmAMh4Fj2HMXy2Og0EuTF0lq0EjrIGgbFcqz+I3BrU271nVeH fzkUWc7H43GObS8fzc6AQAbWhMpWmlJsPGwVRHukT8vRkg/NL9sNpwmkJRLBvILW1I/Q 3qpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date; bh=a1Wl5OOBM+OdiCqwjpRNbQVvWBi9SOkRJQ7j+gqJGAI=; b=yO8r/8yPaKUdwsU5zLnFmcIBwLPPrBqgw0yOKuobIQ7rNsRuCY2+pvXsPX4o5Esg2Q L0rVvx3oX5YUCnzjQnuf5V0cnQWNGegKE6DFhuXBWunPFSHObMw+5dNK3bZnkmAWuDLz YoTZJBLOX5NJw/H/ieAxJUHreZYeEdY1GfLJgAYovRLfZJKXs6FnSSMGsa6j58gCkkt/ rrVd8NX/pmOtdofhMzUalVAaKfeiPCujYKAfJXlDoW4nzvceDW+JbRpXVTQBt6at0GoF 29yA2sogVscyypMgSefyMurptUOcMICeqC3J3rwJpv54DRD7CgZGv52v59ueHQ1606Mp GPpg== X-Gm-Message-State: ACgBeo2VS/sbQFE3EwR3ldQtqzmOajycDBJNWPtQgQd9r+d4QMXju0+0 Dp00VObfoqRCQL5oyNdDB1Lq7so+3FoP2tyhPJdt4Q== X-Google-Smtp-Source: AA6agR5aL8W3+sousDudZxT+/nLQAmWyTAA2BbxmIIkDasYIK+tFHEa7u4ZnJLfSCaHD7jyPJkRRUB/yg6ndTpAc0Jk= X-Received: by 2002:a05:6808:150f:b0:343:3202:91cf with SMTP id u15-20020a056808150f00b00343320291cfmr8032565oiw.112.1662399422082; Mon, 05 Sep 2022 10:37:02 -0700 (PDT) MIME-Version: 1.0 References: <20220905123946.95223-1-likexu@tencent.com> <20220905123946.95223-5-likexu@tencent.com> In-Reply-To: <20220905123946.95223-5-likexu@tencent.com> From: Jim Mattson Date: Mon, 5 Sep 2022 10:36:51 -0700 Message-ID: Subject: Re: [PATCH 4/4] KVM: x86/cpuid: Add AMD CPUID ExtPerfMonAndDbg leaf 0x80000022 To: Like Xu Cc: Sean Christopherson , Paolo Bonzini , Sandipan Das , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Sep 5, 2022 at 5:45 AM Like Xu wrote: > > From: Sandipan Das > > CPUID leaf 0x80000022 i.e. ExtPerfMonAndDbg advertises some > new performance monitoring features for AMD processors. > > Bit 0 of EAX indicates support for Performance Monitoring > Version 2 (PerfMonV2) features. If found to be set during > PMU initialization, the EBX bits of the same CPUID function > can be used to determine the number of available PMCs for > different PMU types. > > Expose the relevant bits via KVM_GET_SUPPORTED_CPUID so > that guests can make use of the PerfMonV2 features. > > Co-developed-by: Like Xu > Signed-off-by: Like Xu > Signed-off-by: Sandipan Das > --- > arch/x86/include/asm/perf_event.h | 8 ++++++++ > arch/x86/kvm/cpuid.c | 21 ++++++++++++++++++++- > 2 files changed, 28 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h > index f6fc8dd51ef4..c848f504e467 100644 > --- a/arch/x86/include/asm/perf_event.h > +++ b/arch/x86/include/asm/perf_event.h > @@ -214,6 +214,14 @@ union cpuid_0x80000022_ebx { > unsigned int full; > }; > > +union cpuid_0x80000022_eax { > + struct { > + /* Performance Monitoring Version 2 Supported */ > + unsigned int perfmon_v2:1; > + } split; > + unsigned int full; > +}; > + > struct x86_pmu_capability { > int version; > int num_counters_gp; > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 75dcf7a72605..08a29ab096d2 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -1094,7 +1094,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) > entry->edx = 0; > break; > case 0x80000000: > - entry->eax = min(entry->eax, 0x80000021); > + entry->eax = min(entry->eax, 0x80000022); > /* > * Serializing LFENCE is reported in a multitude of ways, and > * NullSegClearsBase is not reported in CPUID on Zen2; help > @@ -1203,6 +1203,25 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) > if (!static_cpu_has_bug(X86_BUG_NULL_SEG)) > entry->eax |= BIT(6); > break; > + /* AMD Extended Performance Monitoring and Debug */ > + case 0x80000022: { > + union cpuid_0x80000022_eax eax; > + union cpuid_0x80000022_ebx ebx; > + > + entry->eax = entry->ebx = entry->ecx = entry->edx = 0; > + if (!enable_pmu) > + break; > + > + if (kvm_pmu_cap.version > 1) { > + /* AMD PerfMon is only supported up to V2 in the KVM. */ > + eax.split.perfmon_v2 = 1; > + ebx.split.num_core_pmc = min(kvm_pmu_cap.num_counters_gp, > + KVM_AMD_PMC_MAX_GENERIC); Note that the number of core PMCs has to be at least 6 if guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE). I suppose this leaf could claim fewer, but the first 6 PMCs must work, per the v1 PMU spec. That is, software that knows about PERFCTR_CORE, but not about PMU v2, can rightfully expect 6 PMCs. > + } > + entry->eax = eax.full; > + entry->ebx = ebx.full; > + break; > + } > /*Add support for Centaur's CPUID instruction*/ > case 0xC0000000: > /*Just support up to 0xC0000004 now*/ > -- > 2.37.3 >