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 CCC911369BB; Fri, 4 Oct 2024 10:36:32 +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=1728038195; cv=none; b=ql3Sfevd8iyTysK6uvu5gEABSyxKMX3N05FI4+Hx5HsTF0MalbCMQa6Nkj8DpfqvC0FKdXNwr52t4pnYdLUpZWqAMaCNfhNZCWahIJsgUCPyPNaYFJtJBzc1+GDrrxwFbRjoTZRWq22GNzF+oa1s8Gbdl/5IhqWfBd0Xn7M1wUE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728038195; c=relaxed/simple; bh=GrbPeAK5qkQQQwjlzw5HoXFZHBNyvLny9Hy3BfR+P00=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=B7UM5j5KXvqwjLdW5rQ/RLNnB4GBbOdkOaw6qWPOnGivLT1BZYTi8fn1rhmLrIHoy8ZhXM9NltHmBEz/hymsV8qArnU/K5x0AzpiVJ4Ya0pdQWaQGl9Vr/IfyeBOohnVoImnfGGI992JTb87Z4XsjCbAdMuUFXUsKhzhR/PHIX4= 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=NTzg6eCi; 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="NTzg6eCi" 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:To:From:Sender:Reply-To: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=/QkDROfGDvJqG3hdiAViZ9A3NRJn+vKEY02ZDZuWBAs=; b=NTzg6eCip1bXj4b+mJrtsVSKkG brkV800C7iWdYj9nQZOiN9GF1wqVl54fU3p0Wu0Yf821ssjmHMCtrH2QrbT6sN395/Mmo+gXkU1QU 1h8d2eG9N6Iv5FVjJx+aTEiqb2cYcvp5F4bC7eexjmRPrQhPvCkKN76xU3pDHnxTtPnc=; Received: from localhost.syndicat.com ([127.0.0.1]:54665 helo=localhost) by mail.syndicat.com with esmtp (Syndicat PostHamster 12.2 4.96.1) (envelope-from ) id 1swffQ-0005tE-0T; Fri, 04 Oct 2024 12:36:12 +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 Yx5r5LuOo7ZZ; Fri, 4 Oct 2024 12:36:11 +0200 (CEST) Received: from [62.89.4.53] (port=48282 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 1swffP-0003ug-1l; Fri, 04 Oct 2024 12:36:11 +0200 From: Niels Dettenbach To: x86@kernel.org, Borislav Petkov , =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Cc: Dave Hansen , "H. Peter Anvin" , "Peter Zijlstra (Intel)" , Ingo Molnar , Thomas Gleixner , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [PATCH 1/1] x86: SMP broken on Xen PV DomU since 6.9 Date: Fri, 04 Oct 2024 12:36:09 +0200 Message-ID: <14053472.RDIVbhacDa@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-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart13610981.dW097sEU6C"; 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 --nextPart13610981.dW097sEU6C Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8"; protected-headers="v1" From: Niels Dettenbach Subject: Re: [PATCH 1/1] x86: SMP broken on Xen PV DomU since 6.9 Date: Fri, 04 Oct 2024 12:36:09 +0200 Message-ID: <14053472.RDIVbhacDa@gongov> Organization: Syndicat IT&Internet Disposition-Notification-To: Niels Dettenbach In-Reply-To: <45f3a10c-8695-42cb-abb8-8c13ce1a476b@suse.com> MIME-Version: 1.0 Am Freitag, 4. Oktober 2024, 12:29:57 schrieben Sie: > On 04.10.24 12:05, Niels Dettenbach wrote: > > 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 > Does the attached patch instead of yours help? >=20 > Compile tested only. Thanks J=C3=BCrgen - will try until monday... niels. --nextPart13610981.dW097sEU6C Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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