@@ -135,6 +135,9 @@ struct send_queue {
struct virtnet_sq_stats stats;
struct napi_struct napi;
+
+ /* Record whether sq is in reset state. */
+ bool reset;
};
/* Internal representation of a receive virtqueue */
@@ -279,6 +282,7 @@ struct padded_vnet_hdr {
};
static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf);
+static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
static bool is_xdp_frame(void *ptr)
{
@@ -1603,6 +1607,11 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
return;
if (__netif_tx_trylock(txq)) {
+ if (READ_ONCE(sq->reset)) {
+ __netif_tx_unlock(txq);
+ return;
+ }
+
do {
virtqueue_disable_cb(sq->vq);
free_old_xmit_skbs(sq, true);
@@ -1868,6 +1877,45 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
return err;
}
+static int virtnet_tx_resize(struct virtnet_info *vi,
+ struct send_queue *sq, u32 ring_num)
+{
+ struct netdev_queue *txq;
+ int err, qindex;
+
+ qindex = sq - vi->sq;
+
+ virtnet_napi_tx_disable(&sq->napi);
+
+ txq = netdev_get_tx_queue(vi->dev, qindex);
+
+ /* 1. wait all ximt complete
+ * 2. fix the race of netif_stop_subqueue() vs netif_start_subqueue()
+ */
+ __netif_tx_lock_bh(txq);
+
+ /* Prevent rx poll from accessing sq. */
+ WRITE_ONCE(sq->reset, true);
+
+ /* Prevent the upper layer from trying to send packets. */
+ netif_stop_subqueue(vi->dev, qindex);
+
+ __netif_tx_unlock_bh(txq);
+
+ err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf);
+ if (err)
+ netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err);
+
+ /* Memory barrier before set reset and start subqueue. */
+ smp_mb();
+
+ WRITE_ONCE(sq->reset, false);
+ netif_tx_wake_queue(txq);
+
+ virtnet_napi_tx_enable(vi, sq->vq, &sq->napi);
+ return err;
+}
+
/*
* Send command via the control virtqueue and check status. Commands
* supported by the hypervisor, as indicated by feature bits, should
This patch implements the resize function of the tx queues. Based on this function, it is possible to modify the ring num of the queue. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/net/virtio_net.c | 48 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+)