7957ee71c7
MSI-X works slightly different than INTx; the doorbell registers are not necessarily used as MSI-X interrupts are directed anyway. So the head pointer on the reply queue needs to be updated as soon as a frame is completed, and we can set the doorbell only when in INTx mode. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>