[PATCH 0/6] virtio: graceful failure with get == NULL

["Michael S. Tsirkin" <mst@redhat.com>]

virtio 1.0 says device configuration is optional, but most drivers treat it as
mandatory.  Even if presented by device, guest bios might disable the BAR
holding that configuration, so we can't assume it's there, but we also don't
want to fail if not in case drivers can cope with it's absence - such as caif
or rng.

Add code to drivers to check presence of get callback and fail gracefully.

Michael S. Tsirkin (6):
  virtio/9p: verify device has config space
  virtio/blk: verify device has config space
  virtio/console: verify device has config space
  virtio/net: verify device has config space
  virtio/scsi: verify device has config space
  virtio/balloon: verify device has config space

 drivers/block/virtio_blk.c      | 6 ++++++
 drivers/char/virtio_console.c   | 6 ++++++
 drivers/net/virtio_net.c        | 6 ++++++
 drivers/scsi/virtio_scsi.c      | 6 ++++++
 drivers/virtio/virtio_balloon.c | 6 ++++++
 net/9p/trans_virtio.c           | 6 ++++++
 6 files changed, 36 insertions(+)

-- 
MST