This callback is called by main loop before polling s->fd, if it returns false, the fd will not be polled in this iteration.
This is redundant with checks inside read callback. After this patch, the data will be copied from s->fd to s->iov when it arrives. If the device can't receive, it will be queued to incoming_queue, and when the device status changes, this queue will be flushed. Also remove the qemu_can_send_packet() check in netmap_send. If it's true, we are good; if it's false, the qemu_sendv_packet_async would return 0 and read poll will be disabled until netmap_send_completed is called. Signed-off-by: Fam Zheng <f...@redhat.com> --- net/netmap.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/net/netmap.c b/net/netmap.c index 0c1772b..b3efb5b 100644 --- a/net/netmap.c +++ b/net/netmap.c @@ -132,23 +132,13 @@ error: return -1; } -/* Tell the event-loop if the netmap backend can send packets - to the frontend. */ -static int netmap_can_send(void *opaque) -{ - NetmapState *s = opaque; - - return qemu_can_send_packet(&s->nc); -} - static void netmap_send(void *opaque); static void netmap_writable(void *opaque); /* Set the event-loop handlers for the netmap backend. */ static void netmap_update_fd_handler(NetmapState *s) { - qemu_set_fd_handler2(s->me.fd, - s->read_poll ? netmap_can_send : NULL, + qemu_set_fd_handler2(s->me.fd, NULL, s->read_poll ? netmap_send : NULL, s->write_poll ? netmap_writable : NULL, s); @@ -317,7 +307,7 @@ static void netmap_send(void *opaque) /* Keep sending while there are available packets into the netmap RX ring and the forwarding path towards the peer is open. */ - while (!nm_ring_empty(ring) && qemu_can_send_packet(&s->nc)) { + while (!nm_ring_empty(ring)) { uint32_t i; uint32_t idx; bool morefrag; -- 2.4.1