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| 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 /hw/virtio | |
| parent | 6d0b908a628a7086fa855c68b217cc1e2a5c4c19 (diff) | |
| download | qemu-11380b36196c483ff5c7f800b0f7af6aa53b5657.tar.gz qemu-11380b36196c483ff5c7f800b0f7af6aa53b5657.tar.bz2 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have been queried that can handle the VERSION_1 bit being withdrawn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 'hw/virtio')
| -rw-r--r-- | hw/virtio/virtio-bus.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c index febda76b94..81c7cdd507 100644 --- a/hw/virtio/virtio-bus.c +++ b/hw/virtio/virtio-bus.c @@ -56,6 +56,9 @@ void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp) assert(vdc->get_features != NULL); vdev->host_features = vdc->get_features(vdev, vdev->host_features, errp); + if (klass->post_plugged != NULL) { + klass->post_plugged(qbus->parent, errp); + } } /* Reset the virtio_bus */ |