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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no 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 66CFAC433DB for ; Fri, 15 Jan 2021 18:52:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C855238D7 for ; Fri, 15 Jan 2021 18:52:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733168AbhAOSw0 (ORCPT ); Fri, 15 Jan 2021 13:52:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726751AbhAOSw0 (ORCPT ); Fri, 15 Jan 2021 13:52:26 -0500 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66712C0613C1 for ; Fri, 15 Jan 2021 10:51:46 -0800 (PST) Received: by mail-pg1-x536.google.com with SMTP id z21so6587301pgj.4 for ; Fri, 15 Jan 2021 10:51:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=2ch/HrNBo6bzToTGSnl4rPPwVNGRB87UYiv3EcbSK1A=; b=YQICljedlfUn40WJz//j5+ER9vk1pScXgKsDDNe7FyYz5lsdeqQkqsTFs3I1x7ntX7 XORtjdwUG8HeO2yy9ztInzXwlnAvitykLL5ct3WYSNFdYpMBltGFAyvNIvcsnZlYP289 5zXy4qo4ROo3qeRLPlMjjoTWnr7dwKjTYR2Ou7Kv+3/RhzKCHhabnT/dCb5RThGC0OW8 dToZpdK0ZcgjpT0GSzx13vKYO/WMr77V6Z9KJhNLZ+La21CEgk96ECFn/uvHeT5pgzuR syAbVm0++FXKjvN7WR1qaU6+3KJ6qo5x+LODk8nVTFqcB0hS2w2TmKVedjzeQh8iODjb wk0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=2ch/HrNBo6bzToTGSnl4rPPwVNGRB87UYiv3EcbSK1A=; b=BK+5mVMIFbDaEVubKUXoC3BLEIz/YC9+9YLuwhOuqwOf/LE9BmEFLMPWmT6A/za6Bn Hix1gLYena8b7/hd8AwVfi/jmZ7XuPd8pBZSPV4mo/OQ7CJ/ycUylepfmQMtmrzSZco6 fueKcDGJm9GUcDtbkfnr1lyr3LDILqgyLpBOz3Db2qpZDvTVhp1MLUXOipHAM3hh8YVI 0y4agqgNhAOse4Lq8uXBbwd0tPsCndsF+pm7f+UJcjnk9TLjUcYmiPzp6s1xyK0D97zg roq8t6HHSDIYL72ikBWuetGo67wyTLJjW3GYxIJG1Dt24VfO6RCCBRyr76qGdE887zu2 rqpw== X-Gm-Message-State: AOAM531r4M+NZDjl9jcOJzKGKDnQwKWqo/vF0LyqKPUpJqlmOK3kO0/5 msdNZpWhteHbsg3HPL6Rf7YAtg== X-Google-Smtp-Source: ABdhPJzw+DF3EGhYkuUWWEp4oPb5WDMjMyG9DZjiwqyFa8uXr7OII9LofoGR6AruuCBiYif69f35xw== X-Received: by 2002:a63:4923:: with SMTP id w35mr13774358pga.404.1610736705803; Fri, 15 Jan 2021 10:51:45 -0800 (PST) Received: from google.com ([2620:15c:f:10:1ea0:b8ff:fe73:50f5]) by smtp.gmail.com with ESMTPSA id a18sm8754939pfg.107.2021.01.15.10.51.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 Jan 2021 10:51:45 -0800 (PST) Date: Fri, 15 Jan 2021 10:51:38 -0800 From: Sean Christopherson To: Andi Kleen Cc: "Xu, Like" , Kan Liang , Peter Zijlstra , Paolo Bonzini , eranian@google.com, kvm@vger.kernel.org, Ingo Molnar , Thomas Gleixner , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , wei.w.wang@intel.com, luwei.kang@intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 00/17] KVM: x86/pmu: Add support to enable Guest PEBS via DS Message-ID: References: <20210104131542.495413-1-like.xu@linux.intel.com> <20210115182700.byczztx3vjhsq3p3@two.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210115182700.byczztx3vjhsq3p3@two.firstfloor.org> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Jan 15, 2021, Andi Kleen wrote: > > I'm asking about ucode/hardare. Is the "guest pebs buffer write -> PEBS PMI" > > guaranteed to be atomic? > > Of course not. So there's still a window where the guest could observe the bad counter index, correct?