From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 3E80725F7B9 for ; Thu, 28 May 2026 03:06:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779937588; cv=none; b=ecZSaZdXWeAPhGUqXD3GSneakFT1dvbTW2yAv5JzsAEHsju/UaIKrIO5UpQHV85LSmoKJI63FXeCR6RTKsRYcD0o1SvyDNTba/NakArVXPHzvDsHHVUQ01DaPJDFFlIXmBC8yDa+nmvo1yMJyEax6MfZXUS8eZ5h4wGl5INhN1g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779937588; c=relaxed/simple; bh=FjEGp8HMT0oolbQ26cn1yayF1giLEkRPKwUDUeUuvQ0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=tVeLAfHh/zQ4P6QuOcGHOKVaLgTsD9rWLVr+72dTtvqF9NDLUlx7SaAgdtprYoZlAshzFN+kTaBEXOrWoxa7BeMHnuKwZzOiTAeJI7PIWglv2ylG+7yLSWVEic0psMehLi2OB9eCIiNIWt9B8HNeLPow6o2AY/37AQr9qnzJ4jE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jmattson.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=QPPZgK09; arc=none smtp.client-ip=209.85.216.74 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--jmattson.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="QPPZgK09" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-368edd5fec4so13382110a91.0 for ; Wed, 27 May 2026 20:06:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779937586; x=1780542386; 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=4J5mJMP9YWZVlhj9armvKuV994c2vU0LljAhFOdkDPE=; b=QPPZgK09Mu5/ZwRwDq9UNDEhwTbLbVhf8t6KHMjBMBSeqx0WbN17pQ7EBaFDyAgCbu vi6PF38RXrApE9aJ+7PlHUxRjQB7EyLdIbIWFnvljT1PWzpntr9BdZW9i96CniTNKqcC qxB5I5Y/lVO0hYLRlhye4lmQM90PBGWwr4i9mof4u6VOlWa2b4THJsRXJfhsIgChHVsa mYhI1sLqTavCRHO36UdiInQBQhe3oHs9/n2JpeRo4y9ULheD34D/SkHTnn9gO/B02nkY mgZuPwiGqHTUcS/9fT60BvpeoSmG7lY2TcO8m5f2fy74L9VqNSB4MUUqbZZJup1P8zpK mUbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779937586; x=1780542386; 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=4J5mJMP9YWZVlhj9armvKuV994c2vU0LljAhFOdkDPE=; b=iK/dFgiavV/7jUZRHTpURN7a44VCCucaDvfix1MaDiyNdd/DyEDjBdoWTmcKncuBOx q/j4h1WCdjT/4TkbuFabKcw+G4na1vXut8EfiF1C/Qxn/uGX7vLtGlIQ56hpXFh4Fset PCySMV4vA1Jt1oaVlKF7mQdb60xCTqkqcz5dcgWc1KM0c/vE84BvFHz3QsgvP8rK9rUo Gn2GpmHBGMYZn0wT5cxO/iZgGqUVfVgieSXmorRGesMv7rCd0t4fQ/wfqaQ7FB5p5h2k YRJihDhWw5nuJE7paBNxv8MZAO0vhCcd0RZIQTNKVOfx2qcDE73yFkuaAtYzRrCDO72h EP8Q== X-Forwarded-Encrypted: i=1; AFNElJ9l+DgciCiVxDbD2Tm9hbwuH1MfXRW5OMwEkLwvTsElvaA9JpwpYrcPhREk2y2a1kk8tv4CAUmwMYXuMEI=@vger.kernel.org X-Gm-Message-State: AOJu0YwDj7rDkEhWYBY2n+yPd+7yU+Tc7cn9eGm3IvdMQEK7FZYc8kr0 1eHV8JvTtTgew357Hm2w1DGO8X5zpUdfEfwHwkyU1524+nnCvF9fcZHkIqLBMaFp2wq6WWmNQmi yDOoF+jPM+kxHPA== X-Received: from pjbfa6.prod.google.com ([2002:a17:90a:f0c6:b0:366:260e:87a8]) (user=jmattson job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:5188:b0:369:7421:b36f with SMTP id 98e67ed59e1d1-36a678479d6mr24285194a91.21.1779937586208; Wed, 27 May 2026 20:06:26 -0700 (PDT) Date: Wed, 27 May 2026 20:06:04 -0700 In-Reply-To: <20250421192205.7CC1A7D9@davehans-spike.ostc.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250421192205.7CC1A7D9@davehans-spike.ostc.intel.com> X-Mailer: git-send-email 2.54.0.794.g4f17f83d09-goog Message-ID: <20260528030604.2669758-1-jmattson@google.com> Subject: Re: [PATCH] Handle Ice Lake MONITOR erratum From: Jim Mattson To: dave.hansen@linux.intel.com Cc: andrew.cooper3@citrix.com, len.brown@intel.com, linux-kernel@vger.kernel.org, peterz@infradead.org, rafael.j.wysocki@intel.com, srinivas.pandruvada@linux.intel.com, stable@vger.kernel.org, x86@kernel.org, meenashanmugam@google.com, eranian@google.com, Jim Mattson Content-Type: text/plain; charset="UTF-8" On Mon, Apr 21, 2025 at 12:22:05PM -0700, Dave Hansen wrote: > Andrew Cooper reported some boot issues on Ice Lake servers when > running Xen that he tracked down to MWAIT not waking up. Do the safe > thing and consider them buggy since there's a published erratum. > Note: I've seen no reports of this occurring on Linux. > > Add Ice Lake servers to the list of shaky MONITOR implementations with > no workaround available. Also, before the if() gets too unwieldy, move > it over to a x86_cpu_id array. Additionally, add a comment to the > X86_BUG_MONITOR consumption site to make it clear how and why affected > CPUs get IPIs to wake them up. > > There is no equivalent erratum for the "Xeon D" Ice Lakes so > INTEL_ICELAKE_D is not affected. > > The erratum is called ICX143 in the "3rd Gen Intel Xeon Scalable > Processors, Codename Ice Lake Specification Update". It is Intel > document 637780, currently available here: > > https://cdrdv2.intel.com/v1/dl/getContent/637780 The erratum says, "Due to this erratum, the processor may hang." We are seeing some Ice Lake Xeon E5 machines panic due to hard lockups, and then the kdump kernel dies with "Fatal machine check from unknown source." Is this behavior consistent with this erratum? This seems to only happen on Cloud machines, but we always intercept MONITOR and MWAIT on Ice Lake hosts, so I'm not sure why virtualization would be a factor. Thanks, --jim