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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=ham 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 BA819C3F2D0 for ; Tue, 10 Mar 2020 09:44:30 +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 93C0B2467F for ; Tue, 10 Mar 2020 09:44:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 93C0B2467F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56392 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jBbR7-00088A-QG for qemu-devel@archiver.kernel.org; Tue, 10 Mar 2020 05:44:29 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54581) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jBbQS-0007ce-Kc for qemu-devel@nongnu.org; Tue, 10 Mar 2020 05:43:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jBbQR-0003bI-69 for qemu-devel@nongnu.org; Tue, 10 Mar 2020 05:43:48 -0400 Received: from 14.mo6.mail-out.ovh.net ([46.105.56.113]:43690) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jBbQQ-0003TQ-VB for qemu-devel@nongnu.org; Tue, 10 Mar 2020 05:43:47 -0400 Received: from player691.ha.ovh.net (unknown [10.108.54.119]) by mo6.mail-out.ovh.net (Postfix) with ESMTP id 68CE8203BBD for ; Tue, 10 Mar 2020 10:43:44 +0100 (CET) Received: from kaod.org (lns-bzn-46-82-253-208-248.adsl.proxad.net [82.253.208.248]) (Authenticated sender: groug@kaod.org) by player691.ha.ovh.net (Postfix) with ESMTPSA id 07B2D1054117A; Tue, 10 Mar 2020 09:43:32 +0000 (UTC) Date: Tue, 10 Mar 2020 10:43:29 +0100 From: Greg Kurz To: David Gibson Subject: Re: [PATCH v3 1/2] spapr: Disable legacy virtio devices for pseries-5.0 and later Message-ID: <20200310104329.3dd232d2@bahia.home> In-Reply-To: <20200305113146.6850f04b@bahia.home> References: <20200305043009.611636-1-david@gibson.dropbear.id.au> <20200305043009.611636-2-david@gibson.dropbear.id.au> <20200305113146.6850f04b@bahia.home> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Ovh-Tracer-Id: 7011823147303279078 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedugedruddvtddgtdeiucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepfffhvffukfgjfhfogggtgfesthejredtredtvdenucfhrhhomhepifhrvghgucfmuhhriicuoehgrhhouhhgsehkrghougdrohhrgheqnecukfhppedtrddtrddtrddtpdekvddrvdehfedrvddtkedrvdegkeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhhouggvpehsmhhtphdqohhuthdphhgvlhhopehplhgrhigvrheiledurdhhrgdrohhvhhdrnhgvthdpihhnvghtpedtrddtrddtrddtpdhmrghilhhfrhhomhepghhrohhugheskhgrohgurdhorhhgpdhrtghpthhtohepqhgvmhhuqdguvghvvghlsehnohhnghhnuhdrohhrgh X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 46.105.56.113 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: pair@us.ibm.com, mst@redhat.com, aik@ozlabs.ru, qemu-devel@nongnu.org, paulus@samba.org, clg@kaod.org, mdroth@us.ibm.com, qemu-ppc@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 5 Mar 2020 11:31:46 +0100 Greg Kurz wrote: > On Thu, 5 Mar 2020 15:30:08 +1100 > David Gibson wrote: > > > PAPR specifies a kind of odd, paravirtualized PCI bus, which looks to > > the guess mostly like classic PCI, even if some of the individual > > devices on the bus are PCI Express. One consequence of that is that > > virtio-pci devices still default to being in transitional mode, though > > legacy mode is now disabled by default on current q35 x86 machine > > types. > > > > Legacy mode virtio devices aren't really necessary any more, and are > > causing some problems for future changes. Therefore, for the > > pseries-5.0 machine type (and onwards), switch to modern-only > > virtio-pci devices by default. > > > > This does mean we no longer support guest kernels prior to 4.0, unless > > they have modern virtio support backported (which some distro kernels > > like that in RHEL7 do). > > > > Signed-off-by: David Gibson > > --- > > Reviewed-by: Greg Kurz > > FWIW, I could test the following: > - allows a RHEL7 guest with pre 4.0 kernel to boot, as mentioned > in the changelog > - breaks boot of older RHEL 6.10 guests as expected > - allows migration of older machine types to/from QEMU 4.2 > > Tested-by: Greg Kurz > Wait... I gave a try to virtiofsd and there's a problem: $ ./ppc64-softmmu/qemu-system-ppc64 -device vhost-user-fs-pci Unexpected error in object_property_find() at /home/greg/Work/qemu/qemu-ppc/qom/object.c:1231: qemu-system-ppc64: -device vhost-user-fs-pci: can't apply global virtio-pci.disable-legacy=on: Property '.disable-legacy' not found Aborted (core dumped) It is still not possible to set the disable-legacy prop on the vhost-user-fs-pci device, even without this patch, but QEMU doesn't abort: $ ./ppc64-softmmu/qemu-system-ppc64 -device vhost-user-fs-pci -global virtio-pci.disable-legacy=on qemu-system-ppc64: -device vhost-user-fs-pci: can't apply global virtio-pci.disable-legacy=on: Property '.disable-legacy' not found $ It seems to be related to the fact that vhost-user-fs-pci is a non-transitional only device, as shown with this workaround: --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -4574,7 +4574,7 @@ static void spapr_machine_latest_class_options(MachineClass *mc) * class since it doesn't have a compat_props. */ static GlobalProperty compat[] = { - { TYPE_VIRTIO_PCI, "disable-legacy", "on", }, + { TYPE_VIRTIO_PCI "-transitional", "disable-legacy", "on", }, }; mc->alias = "pseries"; but there's probably a better way to address this. MST, Any suggestion ? > > hw/ppc/spapr.c | 17 +++++++++++++++++ > > 1 file changed, 17 insertions(+) > > > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > > index 2eb0d8f70d..3cfc98ac61 100644 > > --- a/hw/ppc/spapr.c > > +++ b/hw/ppc/spapr.c > > @@ -65,6 +65,7 @@ > > > > #include "hw/pci/pci.h" > > #include "hw/scsi/scsi.h" > > +#include "hw/virtio/virtio-pci.h" > > #include "hw/virtio/virtio-scsi.h" > > #include "hw/virtio/vhost-scsi-common.h" > > > > @@ -4566,8 +4567,20 @@ static const TypeInfo spapr_machine_info = { > > > > static void spapr_machine_latest_class_options(MachineClass *mc) > > { > > + /* > > + * Most defaults for the latest behaviour are inherited from the > > + * base class, but we need to override the (non ppc specific) > > + * default behaviour for virtio. We can't do that from the base > > + * class since it doesn't have a compat_props. > > + */ > > + static GlobalProperty compat[] = { > > + { TYPE_VIRTIO_PCI, "disable-legacy", "on", }, > > + }; > > + > > mc->alias = "pseries"; > > mc->is_default = true; > > + > > + compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat)); > > } > > > > #define DEFINE_SPAPR_MACHINE(suffix, verstr, latest) \ > > @@ -4607,6 +4620,9 @@ DEFINE_SPAPR_MACHINE(5_0, "5.0", true); > > static void spapr_machine_4_2_class_options(MachineClass *mc) > > { > > SpaprMachineClass *smc = SPAPR_MACHINE_CLASS(mc); > > + static GlobalProperty compat[] = { > > + { TYPE_VIRTIO_PCI, "disable-legacy", "auto" }, > > + }; > > > > spapr_machine_5_0_class_options(mc); > > compat_props_add(mc->compat_props, hw_compat_4_2, hw_compat_4_2_len); > > @@ -4614,6 +4630,7 @@ static void spapr_machine_4_2_class_options(MachineClass *mc) > > smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_OFF; > > smc->rma_limit = 16 * GiB; > > mc->nvdimm_supported = false; > > + compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat)); > > } > > > > DEFINE_SPAPR_MACHINE(4_2, "4.2", false); >