From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:59586) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gfMSd-0001Ay-Hs for qemu-devel@nongnu.org; Fri, 04 Jan 2019 05:12:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gfMSZ-0001Kg-Cf for qemu-devel@nongnu.org; Fri, 04 Jan 2019 05:12:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46492) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gfMSZ-0001C6-2Y for qemu-devel@nongnu.org; Fri, 04 Jan 2019 05:12:11 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 999D95F726 for ; Fri, 4 Jan 2019 10:12:08 +0000 (UTC) Date: Fri, 4 Jan 2019 10:12:00 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20190104101200.GA2494@work-vm> References: <20190104032226.21428-1-ehabkost@redhat.com> <20190103232012-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190103232012-mutt-send-email-mst@kernel.org> Subject: Re: [Qemu-devel] [PATCH] compat: Use explicit type names on HW_COMPAT_2_6 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Eduardo Habkost , qemu-devel@nongnu.org, Thomas Huth , Cornelia Huck * Michael S. Tsirkin (mst@redhat.com) wrote: > On Fri, Jan 04, 2019 at 01:22:26AM -0200, Eduardo Habkost wrote: > > The virtio-pci entries in HW_COMPAT_2_6 had an implicit > > assumption: that all virtio-pci subclasses support the > > disable-legacy and disable-modern options. > > > > That assumption was broken by commit f6e501a28ef9 ("virtio: > > Provide version-specific variants of virtio PCI devices"). This > > caused QEMU to crash if using the new -non-transitional or > > -transitional device types: > > > > $ qemu-system-x86_64 -machine pc-i440fx-2.6 \ > > -device virtio-net-pci-non-transitional > > Unexpected error in object_property_find() at qom/object.c:1092: > > qemu-system-x86_64: -device virtio-net-pci-non-transitional: can't apply \ > > global virtio-pci.disable-modern=on: Property '.disable-modern' not found > > Aborted (core dumped) > > > > Replace the virtio-pci.disable-legacy=off and > > virtio-pci.disable-modern=on entries on HW_COMPAT_2_6 with > > explicit entries for each generic virtio device type. > > > > The full list of generic virtio device types was extracted by > > just grepping for ".generic_name". Note that we don't need to > > worry about listing new virtio-pci devices in HW_COMPAT_2_6 in > > the future, because new devices won't require QEMU 2.6 > > compatibility. > > I fully expect that e.g. packed ring support will need > to affect all virtio devices too. And it's likely > that we'll have some new virtio-pci transport features too. > > > This makes the compat entries annoyingly verbose, but is simpler > > than the alternative of making the virtio-pci type inheritance > > rules even more complex. > > God forbid we forgot something, the only way to notice is to > run a cross version migration with an old qemu. > I think we need to come up with something less verbose and fragile. I guess we could use a script like tests/acceptance/virtio_version.py to do a check? As for something less verbose, I guess something is doable with a few macros (more complex but less verbose); or I guess you could add these properties to the other devices but just refuse to operate when they were set the wrong way. Dave > > > Reported-by: Thomas Huth > > Signed-off-by: Eduardo Habkost > > --- > > --- > > include/hw/compat.h | 140 +++++++++++++++++++++++++++++++++++++++++++- > > 1 file changed, 138 insertions(+), 2 deletions(-) > > > > diff --git a/include/hw/compat.h b/include/hw/compat.h > > index 3ca85b037c..fbb6c1138a 100644 > > --- a/include/hw/compat.h > > +++ b/include/hw/compat.h > > @@ -163,11 +163,147 @@ > > .property = "format_transport_address",\ > > .value = "off",\ > > },{\ > > - .driver = "virtio-pci",\ > > + .driver = "vhost-scsi-pci",\ > > .property = "disable-modern",\ > > .value = "on",\ > > },{\ > > - .driver = "virtio-pci",\ > > + .driver = "vhost-scsi-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "vhost-user-blk-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "vhost-user-blk-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "vhost-user-scsi-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "vhost-user-scsi-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "vhost-vsock-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "vhost-vsock-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-9p-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-9p-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-balloon-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-balloon-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-blk-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-blk-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-crypto-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-crypto-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-gpu-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-gpu-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-input-host-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-input-host-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-keyboard-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-keyboard-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-mouse-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-mouse-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-net-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-net-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-rng-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-rng-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-scsi-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-scsi-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-serial-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-serial-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-tablet-pci",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-tablet-pci",\ > > + .property = "disable-legacy",\ > > + .value = "off",\ > > + },{\ > > + .driver = "virtio-vga",\ > > + .property = "disable-modern",\ > > + .value = "on",\ > > + },{\ > > + .driver = "virtio-vga",\ > > .property = "disable-legacy",\ > > .value = "off",\ > > }, > > -- > > 2.18.0.rc1.1.g3f1ff2140 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK