diff options
| author | Cornelia Huck <cornelia.huck@de.ibm.com> | 2015-12-02 18:31:57 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2015-12-02 19:34:11 +0200 |
| commit | 11380b36196c483ff5c7f800b0f7af6aa53b5657 (patch) | |
| tree | 616f8cd145d8c08199f51ba39d9cae715c6d5b9a /include/hw/virtio/virtio-bus.h | |
| parent | 6d0b908a628a7086fa855c68b217cc1e2a5c4c19 (diff) | |
| download | qemu-11380b36196c483ff5c7f800b0f7af6aa53b5657.zip | |
virtio: handle non-virtio-1-capable backend for ccw
If you run a qemu advertising VERSION_1 with an old kernel where
vhost did not yet support VERSION_1, you'll end up with a device
that is {modern pci|ccw revision 1} but does not advertise VERSION_1.
This is not a sensible configuration and is rejected by the Linux
guest drivers.
To fix this, add a ->post_plugged() callback invoked after features
have been queried that can handle the VERSION_1 bit being withdrawn
and change ccw to fall back to revision 0 if VERSION_1 is gone.
Note that pci is _not_ fixed; we'll need to rethink the approach
for the next release but at least for pci it's not a regression.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'include/hw/virtio/virtio-bus.h')
| -rw-r--r-- | include/hw/virtio/virtio-bus.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h index 6c3d4cb19e..3f2c1363d0 100644 --- a/include/hw/virtio/virtio-bus.h +++ b/include/hw/virtio/virtio-bus.h @@ -60,6 +60,11 @@ typedef struct VirtioBusClass { */ void (*device_plugged)(DeviceState *d, Error **errp); /* + * Re-evaluate setup after feature bits have been validated + * by the device backend. + */ + void (*post_plugged)(DeviceState *d, Error **errp); + /* * transport independent exit function. * This is called by virtio-bus just before the device is unplugged. */ |