From 102f29c3a03f4643cda3cee0482b1f410888d60e Mon Sep 17 00:00:00 2001 From: Mark McLoughlin Date: Mon, 11 Aug 2008 21:12:05 +0100 Subject: [PATCH] Remove virtio_net tx ring-full heuristic virtio_net tries to guess when it has received a tx notification from the guest whether it indicates that the guest has no more room in the tx ring and it should immediately flush the queued buffers. The heuristic is based on the fact that there are 128 buffer entries in the ring and each packet uses 2 buffers (i.e. the virtio_net_hdr and the packet's linear data). Using GSO or increasing the size of the rings will break that heuristic, so let's remove it and assume that any notification from the guest after we've disabled notifications indicates that we should flush our buffers. Signed-off-by: Mark McLoughlin Signed-off-by: Avi Kivity --- hw/virtio-net.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/hw/virtio-net.c b/hw/virtio-net.c index 3a39c8f134..b001475875 100644 --- a/hw/virtio-net.c +++ b/hw/virtio-net.c @@ -175,8 +175,7 @@ static void virtio_net_handle_tx(VirtIODevice *vdev, VirtQueue *vq) { VirtIONet *n = to_virtio_net(vdev); - if (n->tx_timer_active && - (vq->vring.avail->idx - vq->last_avail_idx) == 64) { + if (n->tx_timer_active) { vq->vring.used->flags &= ~VRING_USED_F_NO_NOTIFY; qemu_del_timer(n->tx_timer); n->tx_timer_active = 0; -- 2.11.4.GIT