vhost: allow per device message handler

This patch allow device to register its own message handler during
vhost_dev_init(). vDPA device will use it to implement its own DMA
mapping logic.

Signed-off-by: Jason Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>
5 files changed