From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f50.google.com (mail-wm1-f50.google.com [209.85.128.50]) (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 8812F12F399 for ; Mon, 21 Apr 2025 19:32:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745263966; cv=none; b=Zg2ZyBpP0z0Ustvc/no1/LxPphaxkdcK6BNGUHSNj2Ncw274IT9COPBxG/FFICgOUpFyuvLW3HIDqo9sSdA+kFIWSrFaE7kB0AzzFtlgrJkmX/aCFLNK7bfzHwe7J4Fait/u456CHEqxPdZs3YSXeAXhNE14ebgrBOKT4ys4t3g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745263966; c=relaxed/simple; bh=qIbxaMpRyRPS338Tm5o730kOGM0Ig0vZeilxlqEAma0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hA2rDSISFlhiNvQje9tlvINw4K+7K/2VnV1gj9TUqFyXcIr829F7SIg+61KbSToMmp3VXjX1ZIyfacN/J00/n2vaOR3I7FlsRT2AmWo8zX9qWLmYfhdMoQdW8kkHTd1vArQ5iItPjOPNcXLqjHOnz65oEl133HW5Yq/EYuGuOdA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=citrix.com; spf=pass smtp.mailfrom=cloud.com; dkim=pass (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b=blZ2b7+m; arc=none smtp.client-ip=209.85.128.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=citrix.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=cloud.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="blZ2b7+m" Received: by mail-wm1-f50.google.com with SMTP id 5b1f17b1804b1-43cf06eabdaso42539995e9.2 for ; Mon, 21 Apr 2025 12:32:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.com; s=google; t=1745263963; x=1745868763; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=/kacNZ/6skUjkEZrrtvXbll6b4DFBykRT2FZt/z4qKo=; b=blZ2b7+mv0UAqRQM8qnE2g8A+lgugqxPttrid4l57affSJ/ohmBKel3ld+QJoTPgK9 nnu9vfB96dGKC4TtfPxX6YYCfLzo+aKwUdbuyPNzZ7j+Foxsnvz0hvs+i8n8f+2LbX0R saWvsWWsrCYNcbFvwsd5s9j4xpKSo+vRFkruA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1745263963; x=1745868763; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=/kacNZ/6skUjkEZrrtvXbll6b4DFBykRT2FZt/z4qKo=; b=Hn7Tz2ZMg8lu6j6onIAA9tmZNaTwc0srzdcDJHTkWh8gw+xMYTiwBIZeiePZclBMEX M2TXTS0BFaO9CJ4vxWy0u/moAxIJ24ojd3muWzJ2w43kapVZm9AOO/bFTsuzjcrJ3uri cChdXMbdAiK5AQpm0+LrbvsqO38fH+CrVrAVXM+RK1lQ/g8R//gaR1EqfxksIz7vhqNe ikfG6MpkSlzmzqcJO3IWYAOIGayXB6F8Ed8sSWC8ADb5FTdBkKQiB7rBpMLyvsGQ9I48 KTvnfGD3HXuVRavOv21GSB/dFziOQWtwK5WlaPBZmY9MvKsZqtTkCsKMSKl5zOyRDeG5 7n+A== X-Forwarded-Encrypted: i=1; AJvYcCVyc9cX6qOli64AydrEJkyij0Z0t37D9wLJDAVwvVHCamgji/8tHoChvAiseGWVrqVZn4J2NH9DGPGu1qw=@vger.kernel.org X-Gm-Message-State: AOJu0Yxc16PimqZpRf5jqJgmRJram/VCYoqdtH3svCRkq42eSJ7tL4oz ZAflQ9gL+KOTbog8JaBN1NWlqoVT7OlvjFsODHz5HlBbA9xuuudD1bFxYXn0nrQ= X-Gm-Gg: ASbGncuC8Yl/3kawpgZr/0EIPCJ39GIXybV5xWyImDN6rW7lGQYmSu2Ouy/y2YLnzrL djZ1AkpSJf+QiQAeS3kHIfqPOkQbboBzBzI7FEA9bX/OLOQZuo7HV40z7w+OwYSzlGLGvAWNpZq ZL6wOdjvWMqzoH2zp1WiSW+xrSwJuHHML7S6TvUw4G/+foELiCepkqpD09hfoUiDdkjJIpmIZT3 7fmNO7UxIkpDGXR9ISg8OinUMOo2qJP1q+PiKlmsHC420HBCOvl3VJiY+izRacQ9OwsIWp6PseH aPxi3u2zbheicgMHLFup/tbLj3//t/scywZZLBpSrFlsWo/Ox49X2w== X-Google-Smtp-Source: AGHT+IEWF27e2Lk3TsGhhPtp8i9MuVYFTgyYsjytcbKCN2ZLg9KCqINVbRgQ08dNGo3HiHLFyWP2HA== X-Received: by 2002:a05:6000:40dc:b0:39c:30cd:352c with SMTP id ffacd0b85a97d-39efba383bbmr9041307f8f.8.1745263962782; Mon, 21 Apr 2025 12:32:42 -0700 (PDT) Received: from [192.168.86.29] ([83.104.178.215]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-39efa43319csm12972645f8f.38.2025.04.21.12.32.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 21 Apr 2025 12:32:42 -0700 (PDT) Message-ID: <6142d360-889d-44bb-9a94-b5d2084f90e9@citrix.com> Date: Mon, 21 Apr 2025 20:32:41 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] Handle Ice Lake MONITOR erratum To: Dave Hansen , linux-kernel@vger.kernel.org Cc: x86@kernel.org, Len Brown , Peter Zijlstra , "Rafael J. Wysocki" , Srinivas Pandruvada , stable@vger.kernel.org, =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Frediano Ziglio References: <20250421192205.7CC1A7D9@davehans-spike.ostc.intel.com> Content-Language: en-GB From: Andrew Cooper Autocrypt: addr=andrew.cooper3@citrix.com; keydata= xsFNBFLhNn8BEADVhE+Hb8i0GV6mihnnr/uiQQdPF8kUoFzCOPXkf7jQ5sLYeJa0cQi6Penp VtiFYznTairnVsN5J+ujSTIb+OlMSJUWV4opS7WVNnxHbFTPYZVQ3erv7NKc2iVizCRZ2Kxn srM1oPXWRic8BIAdYOKOloF2300SL/bIpeD+x7h3w9B/qez7nOin5NzkxgFoaUeIal12pXSR Q354FKFoy6Vh96gc4VRqte3jw8mPuJQpfws+Pb+swvSf/i1q1+1I4jsRQQh2m6OTADHIqg2E ofTYAEh7R5HfPx0EXoEDMdRjOeKn8+vvkAwhviWXTHlG3R1QkbE5M/oywnZ83udJmi+lxjJ5 YhQ5IzomvJ16H0Bq+TLyVLO/VRksp1VR9HxCzItLNCS8PdpYYz5TC204ViycobYU65WMpzWe LFAGn8jSS25XIpqv0Y9k87dLbctKKA14Ifw2kq5OIVu2FuX+3i446JOa2vpCI9GcjCzi3oHV e00bzYiHMIl0FICrNJU0Kjho8pdo0m2uxkn6SYEpogAy9pnatUlO+erL4LqFUO7GXSdBRbw5 gNt25XTLdSFuZtMxkY3tq8MFss5QnjhehCVPEpE6y9ZjI4XB8ad1G4oBHVGK5LMsvg22PfMJ ISWFSHoF/B5+lHkCKWkFxZ0gZn33ju5n6/FOdEx4B8cMJt+cWwARAQABzSlBbmRyZXcgQ29v cGVyIDxhbmRyZXcuY29vcGVyM0BjaXRyaXguY29tPsLBegQTAQgAJAIbAwULCQgHAwUVCgkI CwUWAgMBAAIeAQIXgAUCWKD95wIZAQAKCRBlw/kGpdefoHbdD/9AIoR3k6fKl+RFiFpyAhvO 59ttDFI7nIAnlYngev2XUR3acFElJATHSDO0ju+hqWqAb8kVijXLops0gOfqt3VPZq9cuHlh IMDquatGLzAadfFx2eQYIYT+FYuMoPZy/aTUazmJIDVxP7L383grjIkn+7tAv+qeDfE+txL4 SAm1UHNvmdfgL2/lcmL3xRh7sub3nJilM93RWX1Pe5LBSDXO45uzCGEdst6uSlzYR/MEr+5Z JQQ32JV64zwvf/aKaagSQSQMYNX9JFgfZ3TKWC1KJQbX5ssoX/5hNLqxMcZV3TN7kU8I3kjK mPec9+1nECOjjJSO/h4P0sBZyIUGfguwzhEeGf4sMCuSEM4xjCnwiBwftR17sr0spYcOpqET ZGcAmyYcNjy6CYadNCnfR40vhhWuCfNCBzWnUW0lFoo12wb0YnzoOLjvfD6OL3JjIUJNOmJy RCsJ5IA/Iz33RhSVRmROu+TztwuThClw63g7+hoyewv7BemKyuU6FTVhjjW+XUWmS/FzknSi dAG+insr0746cTPpSkGl3KAXeWDGJzve7/SBBfyznWCMGaf8E2P1oOdIZRxHgWj0zNr1+ooF /PzgLPiCI4OMUttTlEKChgbUTQ+5o0P080JojqfXwbPAyumbaYcQNiH1/xYbJdOFSiBv9rpt TQTBLzDKXok86M7BTQRS4TZ/ARAAkgqudHsp+hd82UVkvgnlqZjzz2vyrYfz7bkPtXaGb9H4 Rfo7mQsEQavEBdWWjbga6eMnDqtu+FC+qeTGYebToxEyp2lKDSoAsvt8w82tIlP/EbmRbDVn 7bhjBlfRcFjVYw8uVDPptT0TV47vpoCVkTwcyb6OltJrvg/QzV9f07DJswuda1JH3/qvYu0p vjPnYvCq4NsqY2XSdAJ02HrdYPFtNyPEntu1n1KK+gJrstjtw7KsZ4ygXYrsm/oCBiVW/OgU g/XIlGErkrxe4vQvJyVwg6YH653YTX5hLLUEL1NS4TCo47RP+wi6y+TnuAL36UtK/uFyEuPy wwrDVcC4cIFhYSfsO0BumEI65yu7a8aHbGfq2lW251UcoU48Z27ZUUZd2Dr6O/n8poQHbaTd 6bJJSjzGGHZVbRP9UQ3lkmkmc0+XCHmj5WhwNNYjgbbmML7y0fsJT5RgvefAIFfHBg7fTY/i kBEimoUsTEQz+N4hbKwo1hULfVxDJStE4sbPhjbsPCrlXf6W9CxSyQ0qmZ2bXsLQYRj2xqd1 bpA+1o1j2N4/au1R/uSiUFjewJdT/LX1EklKDcQwpk06Af/N7VZtSfEJeRV04unbsKVXWZAk uAJyDDKN99ziC0Wz5kcPyVD1HNf8bgaqGDzrv3TfYjwqayRFcMf7xJaL9xXedMcAEQEAAcLB XwQYAQgACQUCUuE2fwIbDAAKCRBlw/kGpdefoG4XEACD1Qf/er8EA7g23HMxYWd3FXHThrVQ HgiGdk5Yh632vjOm9L4sd/GCEACVQKjsu98e8o3ysitFlznEns5EAAXEbITrgKWXDDUWGYxd pnjj2u+GkVdsOAGk0kxczX6s+VRBhpbBI2PWnOsRJgU2n10PZ3mZD4Xu9kU2IXYmuW+e5KCA vTArRUdCrAtIa1k01sPipPPw6dfxx2e5asy21YOytzxuWFfJTGnVxZZSCyLUO83sh6OZhJkk b9rxL9wPmpN/t2IPaEKoAc0FTQZS36wAMOXkBh24PQ9gaLJvfPKpNzGD8XWR5HHF0NLIJhgg 4ZlEXQ2fVp3XrtocHqhu4UZR4koCijgB8sB7Tb0GCpwK+C4UePdFLfhKyRdSXuvY3AHJd4CP 4JzW0Bzq/WXY3XMOzUTYApGQpnUpdOmuQSfpV9MQO+/jo7r6yPbxT7CwRS5dcQPzUiuHLK9i nvjREdh84qycnx0/6dDroYhp0DFv4udxuAvt1h4wGwTPRQZerSm4xaYegEFusyhbZrI0U9tJ B8WrhBLXDiYlyJT6zOV2yZFuW47VrLsjYnHwn27hmxTC/7tvG3euCklmkn9Sl9IAKFu29RSo d5bD8kMSCYsTqtTfT6W4A3qHGvIDta3ptLYpIAOD2sY3GYq2nf3Bbzx81wZK14JdDDHUX2Rs 6+ahAA== In-Reply-To: <20250421192205.7CC1A7D9@davehans-spike.ostc.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 21/04/2025 8:22 pm, Dave Hansen wrote: > From: Dave Hansen > > 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 > > Signed-off-by: Dave Hansen > Cc: Andrew Cooper > Cc: Rafael J. Wysocki > Cc: Len Brown > Cc: Srinivas Pandruvada > Cc: Peter Zijlstra > Cc: stable@vger.kernel.org CC Roger/Frediano, who did most of the work here.  (I mostly just talked to people). https://lore.kernel.org/xen-devel/20250417161913.14661-1-roger.pau@citrix.com/T/#u ~Andrew > > --- > > b/arch/x86/include/asm/mwait.h | 3 +++ > b/arch/x86/kernel/cpu/intel.c | 17 ++++++++++++++--- > 2 files changed, 17 insertions(+), 3 deletions(-) > > diff -puN arch/x86/kernel/cpu/intel.c~ICX-MONITOR-bug arch/x86/kernel/cpu/intel.c > --- a/arch/x86/kernel/cpu/intel.c~ICX-MONITOR-bug 2025-04-18 13:54:46.022590596 -0700 > +++ b/arch/x86/kernel/cpu/intel.c 2025-04-18 15:15:19.374365069 -0700 > @@ -513,6 +513,19 @@ static void init_intel_misc_features(str > } > > /* > + * These CPUs have buggy MWAIT/MONITOR implementations that > + * usually manifest as hangs or stalls at boot. > + */ > +#define MWAIT_VFM(_vfm) \ > + X86_MATCH_VFM_FEATURE(_vfm, X86_FEATURE_MWAIT, 0) > +static const struct x86_cpu_id monitor_bug_list[] = { > + MWAIT_VFM(INTEL_ATOM_GOLDMONT), > + MWAIT_VFM(INTEL_LUNARLAKE_M), > + MWAIT_VFM(INTEL_ICELAKE_X), /* Erratum ICX143 */ > + {}, > +}; > + > +/* > * This is a list of Intel CPUs that are known to suffer from downclocking when > * ZMM registers (512-bit vectors) are used. On these CPUs, when the kernel > * executes SIMD-optimized code such as cryptography functions or CRCs, it > @@ -565,9 +578,7 @@ static void init_intel(struct cpuinfo_x8 > c->x86_vfm == INTEL_WESTMERE_EX)) > set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR); > > - if (boot_cpu_has(X86_FEATURE_MWAIT) && > - (c->x86_vfm == INTEL_ATOM_GOLDMONT || > - c->x86_vfm == INTEL_LUNARLAKE_M)) > + if (x86_match_cpu(monitor_bug_list)) > set_cpu_bug(c, X86_BUG_MONITOR); > > #ifdef CONFIG_X86_64 > diff -puN arch/x86/include/asm/mwait.h~ICX-MONITOR-bug arch/x86/include/asm/mwait.h > --- a/arch/x86/include/asm/mwait.h~ICX-MONITOR-bug 2025-04-18 15:17:18.353749634 -0700 > +++ b/arch/x86/include/asm/mwait.h 2025-04-18 15:20:06.037927656 -0700 > @@ -110,6 +110,9 @@ static __always_inline void __sti_mwait( > * through MWAIT. Whenever someone changes need_resched, we would be woken > * up from MWAIT (without an IPI). > * > + * Buggy (X86_BUG_MONITOR) CPUs will never set the polling bit and will > + * always be sent IPIs. > + * > * New with Core Duo processors, MWAIT can take some hints based on CPU > * capability. > */ > _