From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:53557) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gf0Ym-0003dq-JX for qemu-devel@nongnu.org; Thu, 03 Jan 2019 05:49:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gf0Yi-0005WI-Mn for qemu-devel@nongnu.org; Thu, 03 Jan 2019 05:49:08 -0500 Date: Thu, 3 Jan 2019 11:48:37 +0100 From: Cornelia Huck Message-ID: <20190103114837.66429dbb.cohuck@redhat.com> In-Reply-To: <6d25cdc7-60f9-a0e0-b3be-d78da86752b5@redhat.com> References: <20181205195704.17605-1-ehabkost@redhat.com> <20181205195704.17605-3-ehabkost@redhat.com> <6d25cdc7-60f9-a0e0-b3be-d78da86752b5@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH for-4.0 v4 2/2] virtio: Provide version-specific variants of virtio PCI devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth Cc: Eduardo Habkost , qemu-devel@nongnu.org, "Michael S. Tsirkin" , Kevin Wolf , Fam Zheng , Amit Shah , qemu-s390x@nongnu.org, Markus Armbruster , Jason Wang , Andrea Bolognani , Wainer dos Santos Moschetta , Max Reitz , Caio Carrara , Gonglei , Laine Stump , Gerd Hoffmann , Stefan Hajnoczi , Cleber Rosa , Paolo Bonzini , Philippe =?UTF-8?B?TWF0aGlldS1EYXVkw6k=?= On Thu, 3 Jan 2019 11:14:44 +0100 Thomas Huth wrote: > On 2019-01-03 10:38, Thomas Huth wrote: > > On 2018-12-05 20:57, Eduardo Habkost wrote: > >> Many of the current virtio-*-pci device types actually represent > >> 3 different types of devices: > >> * virtio 1.0 non-transitional devices > >> * virtio 1.0 transitional devices > >> * virtio 0.9 ("legacy device" in virtio 1.0 terminology) > >> > >> That would be just an annoyance if it didn't break our device/bus > >> compatibility QMP interfaces. With these multi-purpose device > >> types, there's no way to tell management software that > >> transitional devices and legacy devices require a Conventional > >> PCI bus. > >> > >> The multi-purpose device types would also prevent us from telling > >> management software what's the PCI vendor/device ID for them, > >> because their PCI IDs change at runtime depending on the bus > >> where they were plugged. > >> > >> This patch adds separate device types for each of those virtio > >> device flavors: > >> > >> - virtio-*-pci: the existing multi-purpose device types > >> - Configurable using `disable-legacy` and `disable-modern` > >> properties > >> - Legacy driver support is automatically enabled/disabled > >> depending on the bus where it is plugged > >> - Supports Conventional PCI and PCI Express buses > >> (but Conventional PCI is incompatible with > >> disable-legacy=off) > >> - Changes PCI vendor/device IDs at runtime > >> - virtio-*-pci-transitional: virtio-1.0 device supporting legacy drivers > >> - Supports Conventional PCI buses only, because > >> it has a PIO BAR > >> - virtio-*-pci-non-transitional: modern-only > >> - Supports both Conventional PCI and PCI Express buses > >> > >> The existing TYPE_* macros for these types will point to an > >> abstract base type, so existing casts in the code will keep > >> working for all variants. > >> > >> A simple test script (tests/acceptance/virtio_version.py) is > >> included, to check if the new device types are equivalent to > >> using the `disable-legacy` and `disable-modern` options. > >> > >> Acked-by: Andrea Bolognani > >> Reviewed-by: Cornelia Huck > >> Signed-off-by: Eduardo Habkost > > > > Hi Eduardo, > > > > with these new devices, I can trigger an abort on s390x: > > > > $ qemu-system-s390x -M s390-ccw-virtio-2.5 -monitor stdio -no-shutdown > > QEMU 3.1.50 monitor - type 'help' for more information > > (qemu) device_add vhost-scsi-pci-non-transitional > > qemu-system-s390x: hw/core/qdev-properties.c:1236: > > qdev_prop_set_globals: Assertion `prop->user_provided' failed. > > Aborted (core dumped) > FWIW, it happens with x86, too: > > $ qemu-system-x86_64 -M pc-i440fx-2.6 -monitor stdio > QEMU 3.1.50 monitor - type 'help' for more information > (qemu) device_add vhost-scsi-pci-non-transitional > qemu-system-x86_64: hw/core/qdev-properties.c:1236: > qdev_prop_set_globals: Assertion `prop->user_provided' failed. > Aborted (core dumped) > > Only machine types newer than 2.7 seem to be OK. It also fails for vhost-scsi-pci-transitional on 2.6 and older machines. The problem is that HW_COMPAT_2_6 tries to set the disable_modern property, which the version-specific variants of virtio-pci do not have. Not sure how to fix this. The version-specific devices cannot really work on the compat machine.