[PATCH 07/16] virtio-net: support queue reset

[Kangjie Xu]

From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

virtio-net implements queue reset. Queued packets in the corresponding
queue pair are flushed or purged.

Queue reset is currently only implemented for non-vhosts.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 hw/net/virtio-net.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 7ad948ee7c..8396e21a67 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -531,6 +531,19 @@ static RxFilterInfo 
*virtio_net_query_rxfilter(NetClientState *nc)
     return info;
 }
 
+static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t queue_index)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
+
+    if (!nc->peer) {
+        return;
+    }
+
+    qemu_flush_or_purge_queued_packets(nc->peer, true);
+    assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
+}
+
 static void virtio_net_reset(VirtIODevice *vdev)
 {
     VirtIONet *n = VIRTIO_NET(vdev);
@@ -741,6 +754,7 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, 
uint64_t features,
     }
 
     if (!get_vhost_net(nc->peer)) {
+        virtio_add_feature(&features, VIRTIO_F_RING_RESET);
         return features;
     }
 
@@ -3766,6 +3780,7 @@ static void virtio_net_class_init(ObjectClass *klass, 
void *data)
     vdc->set_features = virtio_net_set_features;
     vdc->bad_features = virtio_net_bad_features;
     vdc->reset = virtio_net_reset;
+    vdc->queue_reset = virtio_net_queue_reset;
     vdc->set_status = virtio_net_set_status;
     vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
     vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;
-- 
2.32.0