On Tue, 30 Jun 2020 13:10:37 +0100 Stefan Hajnoczi <stefa...@redhat.com> wrote:
> On Mon, Jun 29, 2020 at 12:27:58PM +0200, Cornelia Huck wrote:
> > virtio-fs devices are only specified for virtio-1, so it is unclear
> > how a legacy or transitional device should behave.
> >
> > Signed-off-by: Cornelia Huck <coh...@redhat.com>
> > ---
>
> I thought that the following already forced VIRTIO 1.0 because it
> doesn't advertize Legacy or Transitional devices:
>
> static const VirtioPCIDeviceTypeInfo vhost_user_fs_pci_info = {
> .base_name = TYPE_VHOST_USER_FS_PCI,
> .non_transitional_name = "vhost-user-fs-pci",
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> .instance_size = sizeof(VHostUserFSPCI),
> .instance_init = vhost_user_fs_pci_instance_init,
> .class_init = vhost_user_fs_pci_class_init,
> };
This indeed makes vhost-user-fs-pci modern-only, I had not spotted that
when I wrote the patch. Other modern-only devices do not go down this
route and use the virtio_pci_force_virtio_1() approach.
>
> Do you have a guest that sees this VIRTIO 1.0 device and still fails to
> negotiate the VERSION_1 feature bit?
>
> > diff --git a/hw/virtio/vhost-user-fs-pci.c b/hw/virtio/vhost-user-fs-pci.c
> > index e11c889d82b3..244205edf765 100644
> > --- a/hw/virtio/vhost-user-fs-pci.c
> > +++ b/hw/virtio/vhost-user-fs-pci.c
> > @@ -44,6 +44,7 @@ static void vhost_user_fs_pci_realize(VirtIOPCIProxy
> > *vpci_dev, Error **errp)
> > vpci_dev->nvectors = dev->vdev.conf.num_request_queues + 2;
> > }
> >
> > + virtio_pci_force_virtio_1(vpci_dev);
>
> Can this be moved to virtio_pci_types_register() so that it
> automatically happens for .non_transitional_name devices?
There are several existing modern-only devices that don't use that kind
of naming scheme...
What bothers me most is that you need to explicitly request a device to
be modern-only, while that should be the default for any newly added
device. Hence the approach with the centralized list of device types
mentioned in a parallel thread. The main problem with that is that the
proxy device starts getting realized before the virtio device with its
id is present... I failed to find a solution so far. But I'd really
like an approach that can work for all transports.
pgpql4Fbs44H2.pgp
Description: OpenPGP digital signature
