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 3B7EEC433F5 for ; Mon, 2 May 2022 23:51:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229473AbiEBXzD (ORCPT ); Mon, 2 May 2022 19:55:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232216AbiEBXyO (ORCPT ); Mon, 2 May 2022 19:54:14 -0400 Received: from mail-oo1-xc32.google.com (mail-oo1-xc32.google.com [IPv6:2607:f8b0:4864:20::c32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4390A6 for ; Mon, 2 May 2022 16:50:44 -0700 (PDT) Received: by mail-oo1-xc32.google.com with SMTP id a23-20020a4ad5d7000000b0035ee70da7a9so851557oot.1 for ; Mon, 02 May 2022 16:50:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=z7Cw+Kh2PwkVaz2CcLvmIqjqnZHIcRL3vzxNDm28vQI=; b=qUJMJzIghsthGyWraON5sQRLlRKSCoeCtBLqhKJxW+nZKX+BqUjkWgnilkYzSgnBqs ZgN1/gkwEi+9c2RnHpNtWioNpP/BXFLJBZdzymI1P+EuPoyeJWQL/nxy1AnvGQ159gqR zXwryGn81LW3dUC6mRtWsiyH4qnVUV+qCk+lcynIagdTX4YkYsJ3A6WfUAZnf2QV0BKv kWxI50BXL7mFaYi67tBF1BlWawAv+ZAAsnLzMI0Vdw3tg7DP8ChWMB7X3AnzKqttwNpo E7TF149IXP7bGqe9ftVMsqI8K5u+dBCsBKqJT/UeB3z3AIs17lfGrqtomLhC/oR0QrF5 ZgQQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=z7Cw+Kh2PwkVaz2CcLvmIqjqnZHIcRL3vzxNDm28vQI=; b=CjDibAv/be6xGZrfJS6B6krUCMQYBjjIofaoM+ZAvffkDl8wn4qdZFSYWjqJS0qxDi JgmevUJSUjYoOaHMRHWlgPJYTwVKfYzFGlcvIY74juvJe/VUzGChg4jdUL7ark4n+72H JDwxKpV1dpVQW6K9QwLMu0yYei3/RgUxy6boZRulI0AfBKuByokAfSnk5eze0GwksxjK DgPFdanl9Op3u1SlAM+Ik92a+aQX06lyGOjK0vUOIoEhLNqEdYKx6VC/nIVQZDrDzOrh NdlhHecHWHSWpW2+F+sI0r5bYVnlDpdRqPFPBVjd/whL99+xCerLamCu6b5r5LgZCZGO ZpzQ== X-Gm-Message-State: AOAM531WQLqHpUKTit5TqjonjpU/pcyldWl/Z6qFgllqROJwYU3NWbUv 8IJOr5fa4weEPh4DyhjbWoIGmdUjMcXMAGeYvg/0JQ== X-Google-Smtp-Source: ABdhPJwXgvnATQa1rZ5EKOQDBk3E5T5DKJmlC3FwomnAmQjTyGDvBY73DuXdqDwMNiO01v0nBWKkIHXKLl9A2AM2Jpw= X-Received: by 2002:a4a:bb10:0:b0:35e:d6a9:3208 with SMTP id f16-20020a4abb10000000b0035ed6a93208mr4306723oop.85.1651535443613; Mon, 02 May 2022 16:50:43 -0700 (PDT) MIME-Version: 1.0 References: <3fef83d9c2b2f7516e8ff50d60851f29a4bcb716.1651058600.git.sandipan.das@amd.com> In-Reply-To: <3fef83d9c2b2f7516e8ff50d60851f29a4bcb716.1651058600.git.sandipan.das@amd.com> From: Jim Mattson Date: Mon, 2 May 2022 16:50:32 -0700 Message-ID: Subject: Re: [PATCH v4 7/7] kvm: x86/cpuid: Fix CPUID leaf 0xA To: Sandipan Das Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, x86@kernel.org, peterz@infradead.org, bp@alien8.de, dave.hansen@linux.intel.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, namhyung@kernel.org, jolsa@kernel.org, tglx@linutronix.de, mingo@redhat.com, pbonzini@redhat.com, like.xu.linux@gmail.com, eranian@google.com, puwen@hygon.cn, ananth.narayan@amd.com, ravi.bangoria@amd.com, santosh.shukla@amd.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org On Wed, Apr 27, 2022 at 4:34 AM Sandipan Das wrote: > > On some x86 processors, CPUID leaf 0xA provides information > on Architectural Performance Monitoring features. It > advertises a PMU version which Qemu uses to determine the > availability of additional MSRs to manage the PMCs. > > Upon receiving a KVM_GET_SUPPORTED_CPUID ioctl request for > the same, the kernel constructs return values based on the > x86_pmu_capability irrespective of the vendor. > > This leaf and the additional MSRs are not supported on AMD > and Hygon processors. If AMD PerfMonV2 is detected, the PMU > version is set to 2 and guest startup breaks because of an > attempt to access a non-existent MSR. Return zeros to avoid > this. > > Fixes: a6c06ed1a60a ("KVM: Expose the architectural performance monitoring CPUID leaf") > Reported-by: Vasant Hegde > Signed-off-by: Sandipan Das > --- > arch/x86/kvm/cpuid.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 4b62d80bb22f..e66ebb747084 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -872,6 +872,11 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) > union cpuid10_eax eax; > union cpuid10_edx edx; > > + if (!static_cpu_has(X86_FEATURE_ARCH_PERFMON)) { Should this be checking kvm_cpu_cap_has(X86_FEATURE_ARCH_PERFMON) instead? > + entry->eax = entry->ebx = entry->ecx = entry->edx = 0; > + break; > + } > + > perf_get_x86_pmu_capability(&cap); > > /* > -- > 2.34.1 >