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authorLaurent Vivier <lvivier@redhat.com>2022-10-20 11:58:46 +0200
committerJason Wang <jasowang@redhat.com>2022-10-28 13:28:52 +0800
commit7550a82259fcf9ce5f1f6443ced779d0eb8afdca (patch)
tree42abd6f57db3904c9b2e77d84a69eff6a9a7794b /hw/net
parentdf8d07081718c29d04d106583d9c300128686cda (diff)
virtio-net: fix TX timer with tx_burst
When virtio_net_flush_tx() reaches the tx_burst value all the queue is not flushed and nothing restart the timer. Fix that by doing for TX timer as we do for bottom half TX: rearming the timer if we find any packet to send during the virtio_net_flush_tx() call. Fixes: e3f30488e5f8 ("virtio-net: Limit number of packets sent per TX flush") Cc: alex.williamson@redhat.com Signed-off-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
Diffstat (limited to 'hw/net')
-rw-r--r--hw/net/virtio-net.c50
1 files changed, 41 insertions, 9 deletions
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 1fbf2f3e19..b6903aea54 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -2536,14 +2536,19 @@ static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
virtio_queue_set_notification(q->tx_vq, 1);
ret = virtio_net_flush_tx(q);
- if (q->tx_bh && ret >= n->tx_burst) {
+ if (ret >= n->tx_burst) {
/*
* the flush has been stopped by tx_burst
* we will not receive notification for the
* remainining part, so re-schedule
*/
virtio_queue_set_notification(q->tx_vq, 0);
- qemu_bh_schedule(q->tx_bh);
+ if (q->tx_bh) {
+ qemu_bh_schedule(q->tx_bh);
+ } else {
+ timer_mod(q->tx_timer,
+ qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
+ }
q->tx_waiting = 1;
}
}
@@ -2644,6 +2649,8 @@ drop:
return num_packets;
}
+static void virtio_net_tx_timer(void *opaque);
+
static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIONet *n = VIRTIO_NET(vdev);
@@ -2661,15 +2668,13 @@ static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
}
if (q->tx_waiting) {
- virtio_queue_set_notification(vq, 1);
+ /* We already have queued packets, immediately flush */
timer_del(q->tx_timer);
- q->tx_waiting = 0;
- if (virtio_net_flush_tx(q) == -EINVAL) {
- return;
- }
+ virtio_net_tx_timer(q);
} else {
+ /* re-arm timer to flush it (and more) on next tick */
timer_mod(q->tx_timer,
- qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
+ qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
q->tx_waiting = 1;
virtio_queue_set_notification(vq, 0);
}
@@ -2702,6 +2707,8 @@ static void virtio_net_tx_timer(void *opaque)
VirtIONetQueue *q = opaque;
VirtIONet *n = q->n;
VirtIODevice *vdev = VIRTIO_DEVICE(n);
+ int ret;
+
/* This happens when device was stopped but BH wasn't. */
if (!vdev->vm_running) {
/* Make sure tx waiting is set, so we'll run when restarted. */
@@ -2716,8 +2723,33 @@ static void virtio_net_tx_timer(void *opaque)
return;
}
+ ret = virtio_net_flush_tx(q);
+ if (ret == -EBUSY || ret == -EINVAL) {
+ return;
+ }
+ /*
+ * If we flush a full burst of packets, assume there are
+ * more coming and immediately rearm
+ */
+ if (ret >= n->tx_burst) {
+ q->tx_waiting = 1;
+ timer_mod(q->tx_timer,
+ qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
+ return;
+ }
+ /*
+ * If less than a full burst, re-enable notification and flush
+ * anything that may have come in while we weren't looking. If
+ * we find something, assume the guest is still active and rearm
+ */
virtio_queue_set_notification(q->tx_vq, 1);
- virtio_net_flush_tx(q);
+ ret = virtio_net_flush_tx(q);
+ if (ret > 0) {
+ virtio_queue_set_notification(q->tx_vq, 0);
+ q->tx_waiting = 1;
+ timer_mod(q->tx_timer,
+ qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
+ }
}
static void virtio_net_tx_bh(void *opaque)