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 X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57702C433E7 for ; Wed, 14 Oct 2020 12:50:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2BEE2173E for ; Wed, 14 Oct 2020 12:50:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JJVoI9zz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730888AbgJNMu2 (ORCPT ); Wed, 14 Oct 2020 08:50:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:43302 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729399AbgJNMu2 (ORCPT ); Wed, 14 Oct 2020 08:50:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602679827; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=MMxmagzUGQGP4XInFkt7451v8xVF11xKUk5UyjYEMMU=; b=JJVoI9zz4deLypUhW762AihleYHLZ7f4lcEii20kkMbgbBEh+9VZzw8+6UKDzjwulA8lz/ 3WtYI9rz9sZe8myICylAt8HeuXcGQg41P8/gVk6ioXTwueSy7juVS6YXibroi5XesagPbs MG0YpPnvM/mGQwExmDriq035XmLR/K4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-153-2Lq70kDlO0Sv7pwogcjvXg-1; Wed, 14 Oct 2020 08:50:25 -0400 X-MC-Unique: 2Lq70kDlO0Sv7pwogcjvXg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E12571062721; Wed, 14 Oct 2020 12:50:23 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.194.105]) by smtp.corp.redhat.com (Postfix) with ESMTP id D0C9760BE2; Wed, 14 Oct 2020 12:50:21 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , linux-kernel@vger.kernel.org Subject: [PATCH] KVM: x86: Filter out more Intel-specific PMU MSRs in kvm_init_msr_list() Date: Wed, 14 Oct 2020 14:50:20 +0200 Message-Id: <20201014125020.2406434-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When running KVM selftest in a Hyper-V VM they stumble upon Unexpected result from KVM_GET_MSRS, r: 14 (failed MSR was 0x309) MSR_ARCH_PERFMON_FIXED_CTR[0..3] along with MSR_CORE_PERF_FIXED_CTR_CTRL, MSR_CORE_PERF_GLOBAL_STATUS, MSR_CORE_PERF_GLOBAL_CTRL, MSR_CORE_PERF_GLOBAL_OVF_CTRL are only valid for Intel PMU ver > 1 but Hyper-V instances have CPUID.0AH.EAX == 0 (so perf code falls back to p6_pmu instead of intel_pmu). Surprisingly, unlike on AMD hardware for example, our rdmsr_safe() check passes and MSRs are not filtered out. MSR_ARCH_PERFMON_FIXED_CTR[0..3] can probably be checked against x86_pmu.num_counters_fixed and the rest is only present with x86_pmu.version > 1. Unfortunately, full elimination of the disconnection between system-wide KVM_GET_MSR_INDEX_LIST/KVM_GET_MSR_FEATURE_INDEX_LIST and per-VCPU KVM_GET_MSRS/KVM_SET_MSRS seem to be impossible as per-vCPU PMU setup depends on guest CPUIDs which can always be altered. Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/x86.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ce856e0ece84..85d72b125fba 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5436,6 +5436,15 @@ static void kvm_init_msr_list(void) min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp)) continue; break; + case MSR_ARCH_PERFMON_FIXED_CTR0 ... MSR_ARCH_PERFMON_FIXED_CTR0 + 3: + if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_FIXED_CTR0 >= + min(INTEL_PMC_MAX_FIXED, x86_pmu.num_counters_fixed)) + continue; + break; + case MSR_CORE_PERF_FIXED_CTR_CTRL ... MSR_CORE_PERF_GLOBAL_OVF_CTRL: + if (x86_pmu.version <= 1) + continue; + break; default: break; } -- 2.25.4