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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 28DB6C433ED for ; Thu, 22 Apr 2021 00:18:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB6216144A for ; Thu, 22 Apr 2021 00:18:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343879AbhDVATY (ORCPT ); Wed, 21 Apr 2021 20:19:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343871AbhDVATX (ORCPT ); Wed, 21 Apr 2021 20:19:23 -0400 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82EC2C06138B for ; Wed, 21 Apr 2021 17:18:48 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id m130-20020a628c880000b029021007090c43so12104292pfd.22 for ; Wed, 21 Apr 2021 17:18:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=InGXRJoehZzqf88O4Bt+zuFetATrFUWqYs8yN3vRqLA=; b=l9+yX1Z7vIwgD/vS0LRjEANK7LrzEFSQS1x8Gr8oiIZIShujccwJ1QurNQu5vqZP4F FVD5t+FBBqjuSgYtxgoZDyRv4izWBSe1Lp8yT82WEqrpEaDFYRP18UwuIttJLqVZCApB zFV5FJKrQYb+pX2en4+9oshJ6eYUpk7SqLq4AkNuPh232UpzRZXVvAgwnOIZ7SdHYWWp yVH2PanXvEqlPGr8mCffE628ISqz2EqfmM71Ok4NBvSOaR+FDF/2f+mmUqsJvqiXbE5W cCCrLlpx4FmwQ28gUyZ+CnjSIGJL0r/RtFv3PVXfkSc6r2fWiJERy5XRCW82osbrqHYc Y8+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=InGXRJoehZzqf88O4Bt+zuFetATrFUWqYs8yN3vRqLA=; b=SWUdfBVrYTahLw9USsFwtNj+reZ3GkiuhldxWPIXrXlCZQHkHT9idL1BpJWfhVMlOf 6EuB+pTFbDt8CCYJQijNKJ976n32W0oBS/sbvmDr/+3W93qUUbMIe0XMMAMiRv72cpjH H/SInTukwK4Ia5T4i77WBH40KvfbJVq9DBO8ap2CaANvynm8Ar0/Q3GcmKIiy4tgm7YU EfmfbaaBt0h098SdTdeQXM8qqqMDpzqtk0/SYh8c7A1BL1YV7bxFd0b+/sBPFLv4ipqZ msTeml1eSA7DyMbmfA+IZTtgnyczCZlTFxRWfvmVgm2FDDyJ6ujKlsO0Bed5xUVjIaE5 Cr4Q== X-Gm-Message-State: AOAM5315EWQ5rsqhqgryomhd7lcqnHTabrZb/BJ7CmxGcYyoCLiQqs4M BAdPs/TEUJHANXUNSKN9LNL/ToVDncBo0w== X-Google-Smtp-Source: ABdhPJzJwJ1k4tRTd5q22O87C7x61PVXv2hGBgVu77fDStDkGXMd3CX3lSCY8kDOvDhwshFVHXo98qs6MyMlrQ== X-Received: from tortoise.c.googlers.com ([fda3:e722:ac3:10:7f:e700:c0a8:1a0d]) (user=jmattson job=sendgmr) by 2002:a62:920d:0:b029:25d:102a:f0a4 with SMTP id o13-20020a62920d0000b029025d102af0a4mr679659pfd.37.1619050727976; Wed, 21 Apr 2021 17:18:47 -0700 (PDT) Date: Wed, 21 Apr 2021 17:18:34 -0700 Message-Id: <20210422001834.1748319-1-jmattson@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.31.1.368.gbe11c130af-goog Subject: [PATCH] perf/x86/kvm: Fix Broadwell Xeon stepping in isolation_ucodes[] From: Jim Mattson To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Kan Liang , Andi Kleen , linux-kernel@vger.kernel.org, kvm-list@vger.kernel.org Cc: Jim Mattson , Peter Shier Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The only stepping of Broadwell Xeon parts is stepping 1. Fix the relevant isolation_ucodes[] entry, which previously enumerated stepping 2. Although the original commit was characterized as an optimization, it is also a workaround for a correctness issue. If a PMI arrives between kvm's call to perf_guest_get_msrs() and the subsequent VM-entry, a stale value for the IA32_PEBS_ENABLE MSR may be restored at the next VM-exit. This is because, unbeknownst to kvm, PMI throttling may clear bits in the IA32_PEBS_ENABLE MSR. CPUs with "PEBS isolation" don't suffer from this issue, because perf_guest_get_msrs() doesn't report the IA32_PEBS_ENABLE value. Fixes: 9b545c04abd4f ("perf/x86/kvm: Avoid unnecessary work in guest filtering") Cc: Andi Kleen Reported-by: Peter Shier Signed-off-by: Jim Mattson Reviewed-by: Peter Shier --- arch/x86/events/intel/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 37ce38403cb8..c57ec8e27907 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -4516,7 +4516,7 @@ static const struct x86_cpu_desc isolation_ucodes[] = { INTEL_CPU_DESC(INTEL_FAM6_BROADWELL_D, 3, 0x07000009), INTEL_CPU_DESC(INTEL_FAM6_BROADWELL_D, 4, 0x0f000009), INTEL_CPU_DESC(INTEL_FAM6_BROADWELL_D, 5, 0x0e000002), - INTEL_CPU_DESC(INTEL_FAM6_BROADWELL_X, 2, 0x0b000014), + INTEL_CPU_DESC(INTEL_FAM6_BROADWELL_X, 1, 0x0b000014), INTEL_CPU_DESC(INTEL_FAM6_SKYLAKE_X, 3, 0x00000021), INTEL_CPU_DESC(INTEL_FAM6_SKYLAKE_X, 4, 0x00000000), INTEL_CPU_DESC(INTEL_FAM6_SKYLAKE_X, 5, 0x00000000), -- 2.31.1.368.gbe11c130af-goog