Calling a vhost operation may fail, for example with disconnected
vhost-user backend, but qemu shouldn't abort in this case.
Log an error instead, except on error and cleanup code paths where it
can be mostly ignored.
Let's use a VHOST_OPS_DEBUG macro to easily disable those messages once
disconnected backend stabilizes.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
162bba7fa8