From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 F103B19AD70; Tue, 22 Apr 2025 06:47:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745304424; cv=none; b=gg1r6pRFgMGtPYYvzJMSHSjIIiXsYzeR/7JONHsccJWFv50pKSliJSwneaOB7K1UR25PGDYb95quYUnyH1on9ZxnuQnzHQWw87jZD4vSfkablY6v3iNqdfCuqTq5NtGbOvC+z0BoqnA0cE2zJRS6lYPZ2JL3lGHIJQW1xXSBGFs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745304424; c=relaxed/simple; bh=248s4YbqUI0bkXldB1s2DNY9icarQmLxLtUIqWeTp48=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=orNi5eT0PAnVyOhuiFcgQCNFnwYGry0dtxTp0LOfmuXW/APmvU8PiEYeziuX4nikI7mjpaT/vR3Lf9aCv3bwwCmr7L4kwYVT+tU1Hyga3gLSDlzklOF6YcJ4j6QCe/PA3K91hqV76lPAwgXzA2fSH8q5k6tvUTc9Nm6ohSyel5I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=P7lqufgC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="P7lqufgC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17BC9C4CEE9; Tue, 22 Apr 2025 06:47:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745304423; bh=248s4YbqUI0bkXldB1s2DNY9icarQmLxLtUIqWeTp48=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=P7lqufgC1r1MRyreG2VdkJT8kZZOh/jxKD4YvTBbtx4CISvgjmXjhpqq/9EmYMIhm jbHU8lSyFbgntE2aIf0qTKkEOjS3pihkKpIlyqnSRHrwxQrLhJkOccoFUW3vHTKM3e ACSYYEGZHwsAKnkji+/29pGUrDCpnpI/pvji6JaoF6wHWgxqwlcUHwIA3Ni2pB1ejM hlEWblTydv21Zmy5NsWr2l2KlbGqUTZTqGX5KGIisxiJ99xC1qk1nxFdShm6ih9Yi+ tccEW6nfFNzHcyCrrxMfJMQj/DXeQ38tYTtHOWEm0LbhQfle6j8NQOTaREOubPj/G/ dxaeooQ8vSteg== Date: Tue, 22 Apr 2025 08:46:59 +0200 From: Ingo Molnar To: Dave Hansen Cc: linux-kernel@vger.kernel.org, x86@kernel.org, andrew.cooper3@citrix.com, Len Brown , Peter Zijlstra , "Rafael J. Wysocki" , Srinivas Pandruvada , stable@vger.kernel.org Subject: Re: [PATCH] Handle Ice Lake MONITOR erratum Message-ID: References: <20250421192205.7CC1A7D9@davehans-spike.ostc.intel.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250421192205.7CC1A7D9@davehans-spike.ostc.intel.com> * 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 > > --- > > 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 */ > + {}, > +}; While it's just an internal helper, macro names should still be intuitive: s/MWAIT_VFM /VFM_MWAIT_BUG or so? Thanks, Ingo