From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 870D81C68B0; Wed, 29 May 2024 21:12:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717017175; cv=none; b=fcWWyKnxqnjhrqNvaSEw1Rpv45RrAp039MfQJUtFfkYJGJNpl2f7AnQ0Rd4+ip2TgqnNatNfmp7ys2cVCCSgMTW5k6IQlxYLp8pdv0RkJlX6k077cGYjTzNYmF1csoewS8NBjDrjh3jyexx9xtYTPfiI7MyoniAwEfQKo8FmaQI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717017175; c=relaxed/simple; bh=WyvJEaiV7vktTeJBx3VE7SviCdnt2j0L8vmtJoH9v9M=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XYBbsndIDXJAgmy10P75sXalXB41br4uVSjPq96SBXYpnBXK0xY9O5nZe35UVY29m03zLcPJfwEvz9q7+ShE/sBGTb/802xyet3zBv5DYzw3n0Vk3oHKexlcOnZUQNXcu7F5cIY4xQkgnhTwTcCA3v7pPmR/4UrCb8uFKWww3Co= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=V94eJpoK; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="V94eJpoK" Received: from [IPV6:2601:646:8002:4641:eb14:ad94:2806:1c1a] ([IPv6:2601:646:8002:4641:eb14:ad94:2806:1c1a]) (authenticated bits=0) by mail.zytor.com (8.17.2/8.17.1) with ESMTPSA id 44TLCPAl3724046 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Wed, 29 May 2024 14:12:25 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 44TLCPAl3724046 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024051501; t=1717017146; bh=dXiIrmdSV6YGWgsb6HsVTYKu3Nn4eD0Hhuc5MMdf2M0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=V94eJpoK7Pauzv0PihWtJ9ZIjlxhYhPW3LzJ4ZdUYEZ5x2JJpvu2AER8MjThSsV+5 aWZkE6hqhCjBlYbJNlpCblhjdAGnNNmSuDYDimD6KZpsqo2jBglOso0H1ViDKxYJFQ pOwWgWCnA1nEY88n8C85KfBqvFfOSiW5a2jgc+yinW0WkEPWAmE4VXLcS44dil/OyY XwwdyFTQP2uzrlGYqwd5/YTkLOPgXLAaqrcQyAFzlQyQCN8mSTpdKdTOfcgXJRgxC6 B149MVWVAK2wZqsTEaQbZyAJCCDM1oxloJ8lXqT3DeDoG6NMDHGX93Y5IilCdg/34V B8FUZ3CKwM94Q== Message-ID: Date: Wed, 29 May 2024 14:12:19 -0700 Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 4/6] x86/irq: Process nmi sources in NMI handler To: Jacob Pan , X86 Kernel , LKML , Thomas Gleixner , Dave Hansen , Ingo Molnar , Borislav Petkov , linux-perf-users@vger.kernel.org, Peter Zijlstra Cc: Andi Kleen , Xin Li References: <20240529203325.3039243-1-jacob.jun.pan@linux.intel.com> <20240529203325.3039243-5-jacob.jun.pan@linux.intel.com> Content-Language: en-US From: "H. Peter Anvin" In-Reply-To: <20240529203325.3039243-5-jacob.jun.pan@linux.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 5/29/24 13:33, Jacob Pan wrote: > + > + rcu_read_lock(); > + /* Bit 0 is for unknown NMI sources, skip it. */ > + for_each_set_bit_from(vec, &source_bitmask, NR_NMI_SOURCE_VECTORS) { > + a = rcu_dereference(nmiaction_src_table[vec]); > + if (!a) { > + pr_warn_ratelimited("NMI received %d no handler", vec); > + continue; > + } In this case, you should assume some chipset hardware or VMM is giving you garbage in the event bitmask, and treat it as if bit 0 were set. -hpa