From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5BAF61940A1 for ; Fri, 14 Feb 2025 21:08:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739567326; cv=none; b=UDpYAue6Z0KqwP6D4LCCL91Lx8GirBP/PpNr1KAr6wNI9e1DEkjTgl7ZQyZBfksJHWP++J2iZbbKElw5b2D7j5xE94Wj+ATMRFs24OXdt+KI4qSI806jSOKaxZ8R1UO9cub7Bfbm3Z+cxG8w9AE8UQOjXYc0M1zTQP8cgIH4xxY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739567326; c=relaxed/simple; bh=TABwW3ceukCNtXZ6II8q8PhTuJdg9NELJOoW5SvPSxI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=aUNzrKciWPHafPJSGCco7YKIa+WEX0sXXYP6HRen+hu0WkDuXYgHefVsMTDgzyQ24/djd9WIbpLagFfTZqLlM6yzPI4d4756aFCT6KJnikMGKh3WZUW+aAZN0BdO8u19CfCiWJKrWRkLl0XunDnWPZufmAiTsdlQU2/18KOfOsk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=o2AyZwLk; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="o2AyZwLk" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-21fb94c7fc6so51203695ad.1 for ; Fri, 14 Feb 2025 13:08:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1739567324; x=1740172124; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=NDk9Bd6Y/gy2sTN8NncOlmLs9sUGP6oX096KSBQmv2E=; b=o2AyZwLkD2ETHCjiegJneBZ50czWafrXH93eGhdfIT4qsM1KrykBi/SK5kjZ8AGMbj J/dFV1r2rOTgkgWyPfspmSaRzx0jAcx2avbO6o9Lle5PL1O8BLDmLlzvU3J6rUweZ1SS dpql/SdfhF/S+5OgcqEW/tYWTSMwgCiqYAwiMPFESjgnLnN6oSnXdPQh7YvfF71zIuTr A6H7RfeW0kaSBYz6fS2QI5hZYnbPRa/zWoqcRiw+8bhRLbjdB6uBXHcr5pV2/3klyjDI vUo4NTXJw/yBCCDdj0WXZHrjYS6UHSDQLKt3nFKJkym8zF5GSAOrwkFuXTJPHux0kyhV 9Jvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739567324; x=1740172124; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=NDk9Bd6Y/gy2sTN8NncOlmLs9sUGP6oX096KSBQmv2E=; b=IAOsWuFCxSfdGLXvsUvMYnlV142jHLKujBcf9MsidSqQAtWjHdEGpP5MWJ1HrhWB2E BOghFTjudnjT47Y1nRU7j9ocz864T8rWfzbKr+C6JEqAZnaqRXyIAaGl0rOid9K2t/+7 XhU0dsCjtwUqEKcsdI4VUTipkr9K2swOvcNFtwCqBN8Chkpx5+W7mY9t8gbdSRpy04Zo l8hxG9Bgk/P+ICsHex+eTMP3r1kfTm7OK78K2NXlkXczlKuRCjwiuLRZxrjY+0OWQp2Z xoDLJ/PUy4bH0U0TGrkqaxcgTEb5m2Ug2NKNKqv2t29rWErVKzIvyVkNV1eGDw6cb0/c 1r9A== X-Forwarded-Encrypted: i=1; AJvYcCXJPSDhcKYLYS51nwZ0EFX9E8LrrIr/sslKZbK2ZW0+AL8CJgw1vSAmNT+Hpkg2famLywqWfjusEtwyufI=@vger.kernel.org X-Gm-Message-State: AOJu0YyUdHtXAtM5V1rWjlCr1cZxhNsSE0bQFVUMPABuZKZS5S1lfUTj dnRjSLO65S26nvTUqdA+4H6VaORNeslOl2X0NUrQX6Oscm2zNj2BjXwBOgsU1ZEGK/PYESHask1 7/g== X-Google-Smtp-Source: AGHT+IHGrqSV53zwVxDPFhenez3hyCmOAIu+9D/XKocIxWU0Dw1My/XXweOF81M6LpwkA3MOCD/JQLSXGkQ= X-Received: from pgf7.prod.google.com ([2002:a05:6a02:4d07:b0:ad7:adb7:8c14]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:2341:b0:21f:9107:fca3 with SMTP id d9443c01a7336-2210405c6ccmr11127175ad.30.1739567324694; Fri, 14 Feb 2025 13:08:44 -0800 (PST) Date: Fri, 14 Feb 2025 13:08:43 -0800 In-Reply-To: <20240914101728.33148-14-dapeng1.mi@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240914101728.33148-1-dapeng1.mi@linux.intel.com> <20240914101728.33148-14-dapeng1.mi@linux.intel.com> Message-ID: Subject: Re: [kvm-unit-tests patch v6 13/18] x86: pmu: Improve instruction and branches events verification From: Sean Christopherson To: Dapeng Mi Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Jim Mattson , Mingwei Zhang , Xiong Zhang , Zhenyu Wang , Like Xu , Jinrong Liang , Yongwei Ma , Dapeng Mi Content-Type: text/plain; charset="us-ascii" On Sat, Sep 14, 2024, Dapeng Mi wrote: > If HW supports GLOBAL_CTRL MSR, enabling and disabling PMCs are moved in > __precise_count_loop(). Thus, instructions and branches events can be > verified against a precise count instead of a rough range. > > BTW, some intermittent failures on AMD processors using PerfMonV2 is > seen due to variance in counts. This probably has to do with the way > instructions leading to a VM-Entry or VM-Exit are accounted when > counting retired instructions and branches. AMD counts VMRUN as a branch in guest context. > + * We see some intermittent failures on AMD processors using PerfMonV2 > + * due to variance in counts. This probably has to do with the way > + * instructions leading to a VM-Entry or VM-Exit are accounted when > + * counting retired instructions and branches. Thus only enable the > + * precise validation for Intel processors. > + */ > + if (pmu.is_intel && this_cpu_has_perf_global_ctrl()) { > + /* instructions event */ These comments are useless. > + gp_events[instruction_idx].min = LOOP_INSTRNS; > + gp_events[instruction_idx].max = LOOP_INSTRNS; > + /* branches event */ > + gp_events[branch_idx].min = LOOP_BRANCHES; > + gp_events[branch_idx].max = LOOP_BRANCHES; > + } > +}