151fcdfd62
The virtio standard specifies that any non-transitional device must reject commands prior to revision setting (which we do). Devices that are transitional need to assume revision 0 (legacy) if the driver sends a non-revision-setting command first in order to support legacy drivers. We neglected to do the latter. Fortunately, nearly everything worked as intended anyway; the only problem was not properly rejecting revision setting after some other command had been issued. Easy to fix by setting revision to 0 if we see a non-revision command on a legacy-capable revision-less device. Found by code inspection, not observed in the wild. Signed-off-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Halil Pasic <pasic@linux.ibm.com> Message-Id: <20210216111830.1087847-1-cohuck@redhat.com>