From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 876C9C432C3 for ; Wed, 20 Nov 2019 11:43:09 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 52D9B21906 for ; Wed, 20 Nov 2019 11:43:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="GUhPW766" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 52D9B21906 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56776 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iXOO4-0001wh-Fb for qemu-devel@archiver.kernel.org; Wed, 20 Nov 2019 06:43:08 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:42891) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iXOMs-0000xf-FM for qemu-devel@nongnu.org; Wed, 20 Nov 2019 06:41:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iXOMp-0007GX-Pl for qemu-devel@nongnu.org; Wed, 20 Nov 2019 06:41:54 -0500 Received: from bilbo.ozlabs.org ([2401:3900:2:1::2]:42757 helo=ozlabs.org) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iXOMo-00078x-WD; Wed, 20 Nov 2019 06:41:51 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 47J14T2cTkz9sPc; Wed, 20 Nov 2019 22:41:45 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1574250105; bh=xm/OD7gHeqIK4V+e5RzwnfYaJi2fQC8X9pkmZJcIJqo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GUhPW766y0JWPtM9MDBSIxTN8ffRomhwEMpynGNRDG41ePqNu1n+/+M0Riw5yzCiP /gsyBYVP/oY+EfTu5SfwaY7HqtOrXnCz2KaN8RaTNwz+rr5LANMNXyEfexhiqYz5He /DLQK1hlbcc9RMEjhvk7xU1/cmYj+XNau2aiLSJQ= Date: Wed, 20 Nov 2019 22:41:28 +1100 From: David Gibson To: Laurent Vivier Subject: Re: [PATCH] spapr: Fix VSMT mode when it is not supported by the kernel Message-ID: <20191120114128.GN5582@umbus.fritz.box> References: <20191108154035.12913-1-lvivier@redhat.com> <20191108174759.2d4040f1@bahia.lan> <20191119010012.GI5582@umbus.fritz.box> <20191119164526.0e980a37@bahia.lan> <20191120043653.GG5582@umbus.fritz.box> <0c1f57ac-0823-4268-429b-d1aee8f7f8d5@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="L0wVL3lRYNLgmYWy" Content-Disposition: inline In-Reply-To: <0c1f57ac-0823-4268-429b-d1aee8f7f8d5@redhat.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2401:3900:2:1::2 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?utf-8?B?THVrw6HFoQ==?= Doktor , Juan Quintela , qemu-devel@nongnu.org, Greg Kurz , "Dr . David Alan Gilbert" , qemu-ppc@nongnu.org, clg@kaod.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --L0wVL3lRYNLgmYWy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Nov 20, 2019 at 12:28:19PM +0100, Laurent Vivier wrote: > On 20/11/2019 10:00, Laurent Vivier wrote: > > On 20/11/2019 05:36, David Gibson wrote: > >> On Tue, Nov 19, 2019 at 04:45:26PM +0100, Greg Kurz wrote: > >>> On Tue, 19 Nov 2019 15:06:51 +0100 > >>> Laurent Vivier wrote: > >>> > >>>> On 19/11/2019 02:00, David Gibson wrote: > >>>>> On Fri, Nov 08, 2019 at 05:47:59PM +0100, Greg Kurz wrote: > >>>>>> On Fri, 8 Nov 2019 16:40:35 +0100 > >>>>>> Laurent Vivier wrote: > >>>>>> > >>>>>>> Commit 29cb4187497d sets by default the VSMT to smp_threads, > >>>>>>> but older kernels (< 4.13) don't support that. > >>>>>>> > >>>>>>> We can reasonably restore previous behavior with this kernel > >>>>>>> to allow to run QEMU as before. > >>>>>>> > >>>>>>> If VSMT is not supported, VSMT will be set to MAX(8, smp_threads) > >>>>>>> as it is done for previous machine types (< pseries-4.2) > >>>>>>> > >>>>>> > >>>>>> It is usually _bad_ to base the machine behavior on host capabilit= ies. > >>>>>> What happens if we migrate between an older kernel and a recent on= e ? > >>>>> > >>>>> Right. We're really trying to remove instaces of such behaviour. = I'd > >>>>> prefer to completely revert Greg's original patch than to re-introd= uce > >>>>> host configuration dependency into the guest configuration.. > >>>>> > >>>>>> I understand this is to fix tests/migration-test on older kernels. > >>>>>> Couldn't this be achieved with migration-test doing some introspec= tion > >>>>>> and maybe pass vsmt=3D8 on the QEMU command line ? > >>>>> > >>>>> ..adjusting the test case like this might be a better idea, though. > >>>>> > >>>>> What's the test setup where we're using the old kernel? I really o= nly > >>>>> applied the original patch on the guess that we didn't really care > >>>>> about kernels that old. The fact you've hit this in practice makes= me > >>>>> doubt that assumption. > >>>>> > >>>> > >>>> The way to fix the tests is to add "-smp threads=3D8" on the command= line > >>>> (for all tests, so basically in qtest_init_without_qmp_handshake(), = and > >>>> it will impact all the machine types), and we have to check if it is > >>> > >>> Ohhh... it isn't possible to initialize Qtest with machine specific > >>> properties ? That's a bit unfortunate :-\ > >> > >> Uhh... I don't see why we can't. Couldn't we just put either -machine > >> vsmt=3D8 or -smp 8 into the cmd_src / cmd_dst printfs() in the > >> strcmp(arch, "ppc64") case? > >=20 > > Yes, but we need to do that to all other tests that fail. test-migration > > is not the only one impacted by the problem (we have also pxe-test), so > > it's why I thought to fix the problem in a generic place. > >=20 > > But it seems there are only this couple of tests that are impacted so I > > can modify both instead. I think only tests that really start CPU have > > the problem. > >=20 > > I'm going to send a patch to fix that. >=20 > And again, it's a little bit more complicated than expected: setting > vsmt to 8 works only with kvm_hv, but breaks in case of TCG or kvm_pr. > So the test must check what is in use... Ugh, yeah, that's getting too ugly. I think the feasible options are either to revert the patch, or just say that upstream qemu no longer supports a RHEL7 host. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --L0wVL3lRYNLgmYWy Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAl3VJmYACgkQbDjKyiDZ s5LVww/9Gsbxgu86Sx6FHj5lzp8rEFC5hNHIsaNLB8jort06k0nhzwGR/81SqaZu mWwwSzrXYGVsCtlUy+cs30n7niktbJ62Rs7GC2hpK/Xhm/W2NTVSw8xc0Aq6R2LI duAzsKB2rJG4n3jeM3yDwpkXYa5j0r2dYgRoXqobfaM1cNKJseuNVlXfGVnWZjZi 6dgxWNSNsQDs9gCIx2DRqbkCNvHqldYa3nNFw4N4dAJu9U5Rrty+r8BPepetmduf NuS1rCoVX+i41JaHT4ULEtAvGG0GI8oc/qqm8x5ZORQaJYQ3kU2EAISE1IExeToO XtXrfhFkpF8sM/r3bVaXNcTlWPvAjIZPJCzb5W7ILmh/vnDaSh9SZXejtZz+W6D6 2HFID4rZYrcmnOVe6BZOvMSZCo1m/NDl73ZDZOik8LNyTNPVYHowcz4SJYmS3Kj1 eBQBVA8JJ44/JUDjkvE8zT4r6W1dbXRih43NCNmuDGG0MuaioOrU2LjX/4BUYnc4 V9yIrRFQdeKh+YJAVWyt4FEWGddjTxGM4RfjIokQViSXLJgTyjkHJTHRYLMC8Y+P NwNW+/ttLJc0p9hApAu7cgNUEqUQmtU4muq2Hezb8K3o3gYf1WmfwwxhrIx+oiCC 4HETOfO8rzyaPsxBiGh8y/6osGs00MhzxaFkog6++Wm82Uxvpk0= =vx8b -----END PGP SIGNATURE----- --L0wVL3lRYNLgmYWy--