virtio: remove NO_NOTIFY optimization

NO_NOTIFY is an optimization to reduce the number of exits,
but using it requires careful synchronization with host,
forcing read/write ordering for the CPU. Otherwise we
risk not kicking a host when it is waiting for more buffers,
resulting in a deadlock.

Let's just always kick, it's way simpler.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
1 file changed
tree: b783159cf1b04002b43ea0641f2a81d83e2f7d8b
  1. .gitignore
  2. COPYING
  3. COPYING.LESSER
  4. Makefile
  5. README
  6. TODO
  7. src/
  8. tools/
  9. vgasrc/