guest to remote communication with vhost net sometimes stops until guest driver is restarted. This happens when we get guest kick precisely when the backend send queue is full, as a result handle_tx() returns without polling backend. This patch fixes this by restarting tx poll on this condition. Signed-off-by: Sridhar Samudrala <samudrala@us.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Tom Lendacky <toml@us.ibm.com>