From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.syndicat.com (mail.syndicat.com [62.146.89.62]) (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 884B94317E; Mon, 7 Oct 2024 10:30:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.146.89.62 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728297043; cv=none; b=GZwCb3K3hSnSB48gWjH3pkerk9MjRSWIxfIM0QVzGnwizVgbOp0ybIV5HcRM9YIcTswTaOeUaZ2Fz+vyFv/55vqW/3Ue9DDiQcg7513WC4p05LQ4Xb9boWUyS//jKANVdSrZghwCTnix2syLn8vZ9qPBu8GPwg4RU429Tx0tDK0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728297043; c=relaxed/simple; bh=ZDdQxa2zW8ATvib8cfZrqB0d6UaFhGcApr3Y+DfNnoE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=uyYZYc7Vmn2xOfRTe/6vr2uxxGDF1o/EvN4RnSI6uAYVmBS4BDVmbaoAzJEN8t5L7Yvgl/AacdnxKL6nDRLSemdls0c82+v1VIxmZrXaAqNNQryFkGXSAVK/KyNOgD9MO87nTPK5GcgoCh2jlXMGTg9L1yeNRx0B9P1NbBYgDrk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=syndicat.com; spf=pass smtp.mailfrom=syndicat.com; dkim=pass (1024-bit key) header.d=syndicat.com header.i=@syndicat.com header.b=q80ZG8fe; arc=none smtp.client-ip=62.146.89.62 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=syndicat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=syndicat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=syndicat.com header.i=@syndicat.com header.b="q80ZG8fe" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=syndicat.com; s=x; h=Content-Type:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:Reply-To:To:From:Sender:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=EAprCz2Gwkm9+pncvZr2IJ9AQor7OnWEiPmOKypE4qM=; b=q80ZG8feEmafqmtw50AGULQgzC IwN3tCOeXvM5hn1fH50Ucu4L6mzmZIoDlIrYPC0yiQNideCrU3IdTqYtQ50ikYSSj0bTzM7voe/9D BYz1SC6qdLx8BGQJUAgxcfKWBkMnJ8JNITx6w3PL5lejmIZKo+Sb5KSRO4s7wBs5YoSE=; Received: from localhost.syndicat.com ([127.0.0.1]:62311 helo=localhost) by mail.syndicat.com with esmtp (Syndicat PostHamster 12.2 4.96.1) (envelope-from ) id 1sxkzy-0002o3-0X; Mon, 07 Oct 2024 12:29:54 +0200 X-Virus-Scanned: amavisd-new at syndicat.com Received: from mail.syndicat.com ([127.0.0.1]) by localhost (mail.syndicat.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id S8PNeOnJl_IF; Mon, 7 Oct 2024 12:29:53 +0200 (CEST) Received: from [62.89.4.53] (port=62965 helo=gongov.localnet) by mail.syndicat.com with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Syndicat PostHamster 12.2 4.96.1) (envelope-from ) id 1sxkzx-0007Je-1p; Mon, 07 Oct 2024 12:29:53 +0200 From: Niels Dettenbach To: x86@kernel.org, "H. Peter Anvin" Reply-To: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Cc: Borislav Petkov , Dave Hansen , "Peter Zijlstra (Intel)" , Ingo Molnar , Thomas Gleixner , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, xen-devel@lists.xenproject.org Subject: Re: [PATCH 1/1] x86: SMP broken on Xen PV DomU since 6.9 Date: Mon, 07 Oct 2024 12:29:46 +0200 Message-ID: <3635258.LM0AJKV5NW@gongov> Organization: Syndicat IT&Internet In-Reply-To: <45f3a10c-8695-42cb-abb8-8c13ce1a476b@suse.com> References: <2210883.Icojqenx9y@gongov> <864022534.0ifERbkFSE@gongov> <45f3a10c-8695-42cb-abb8-8c13ce1a476b@suse.com> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart16948470.geO5KgaWL5"; micalg="pgp-sha512"; protocol="application/pgp-signature" X-Report-Abuse-To: abuse@syndicat.com (see https://www.syndicat.com/kontakt/kontakte/) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - mail.syndicat.com X-AntiAbuse: Original Domain - X-AntiAbuse: Sender Address Domain - syndicat.com --nextPart16948470.geO5KgaWL5 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8"; protected-headers="v1" From: Niels Dettenbach To: x86@kernel.org, "H. Peter Anvin" Reply-To: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Subject: Re: [PATCH 1/1] x86: SMP broken on Xen PV DomU since 6.9 Date: Mon, 07 Oct 2024 12:29:46 +0200 Message-ID: <3635258.LM0AJKV5NW@gongov> Organization: Syndicat IT&Internet In-Reply-To: <45f3a10c-8695-42cb-abb8-8c13ce1a476b@suse.com> MIME-Version: 1.0 Am Freitag, 4. Oktober 2024, 12:29:57 schrieb J=C3=BCrgen Gro=C3=9F: > On 04.10.24 12:05, Niels Dettenbach wrote: >=20 > > Virtual machines under Xen Hypervisor (DomU) running in Xen PV mode use > > a > > special, nonstandard synthetized CPU topology which "just works" under > > kernels 6.9.x while newer kernels wrongly assuming a "crash kernel" and > > disable SMP (reducing to one CPU core) because the newer topology > > implementation produces a wrong error "[Firmware Bug]: APIC enumeration > > order not specification compliant" after new topology checks which are > > improper for Xen PV platform. As a result, the kernel disables SMP and > > activates just one CPU core within the PV DomU "VM" (DomU in PV mode). > >=20 > > The patch disables the regarding checks if it is running in Xen PV > > mode (only) and bring back SMP / all CPUs as in the past to such DomU > > VMs. The Xen subsystem takes care of the proper interaction between > > "guest" (DomU) and the "host" (Dom0). > >=20 > > Signed-off-by: Niels Dettenbach >=20 >=20 > Does the attached patch instead of yours help? >=20 > Compile tested only. it does =C3=9F))) domU: =2D- snip -- vcpus=3D6 cpu=3D"12,13,14,15,23,24" =2D- snap -- =2D- snip -- [ 0.500458] cpu 0 spinlock event irq 1 [ 0.500485] VPMU disabled by hypervisor. [ 0.501273] Performance Events: unsupported p6 CPU model 62 no PMU drive= r, software events only. [ 0.501304] signal: max sigframe size: 1776 [ 0.501410] rcu: Hierarchical SRCU implementation. [ 0.501428] rcu: Max phase no-delay instances is 400. [ 0.502032] NMI watchdog: Perf NMI watchdog permanently disabled [ 0.502309] smp: Bringing up secondary CPUs ... [ 0.502759] installing Xen timer for CPU 2 [ 0.503384] installing Xen timer for CPU 4 [ 0.503838] cpu 2 spinlock event irq 16 [ 0.503870] cpu 4 spinlock event irq 17 [ 0.504867] installing Xen timer for CPU 1 [ 0.505495] installing Xen timer for CPU 3 [ 0.506125] installing Xen timer for CPU 5 [ 0.506363] cpu 1 spinlock event irq 33 [ 0.507869] cpu 3 spinlock event irq 34 [ 0.507901] cpu 5 spinlock event irq 35 [ 0.507923] smp: Brought up 1 node, 6 CPUs =2D- snap -- thank you very much! niels. --nextPart16948470.geO5KgaWL5 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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