linux-next: manual merge of the virtio tree with the net-next tree

From: Stephen Rothwell
Date: Sun Dec 09 2012 - 21:28:10 EST

Hi Rusty,

Today's linux-next merge of the virtio tree got a conflict in
drivers/net/virtio_net.c between commit e9d7417b97f4 ("virtio-net:
separate fields of sending/receiving queue from virtnet_info") and
986a4f4d452d ("virtio_net: multiqueue support") from the net-next tree
and commit a89f05573fa2 ("virtio-net: remove unused skb_vnet_hdr->num_sg
field"), 2c6d439a7316 ("virtio-net: correct capacity math on ring full"),
e794093a52cd ("virtio_net: don't rely on virtqueue_add_buf() returning
capacity") and 7dc5f95d9b6c ("virtio: net: make it clear that
virtqueue_add_buf() no longer returns > 0") from the virtio tree.

I fixed it up (I think - see below) and can carry the fix as necessary
(no action is required).

--
Cheers,
Stephen Rothwell sfr@xxxxxxxxxxxxxxxx

diff --cc drivers/net/virtio_net.c
index a644eeb,6289891..0000000
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@@ -523,20 -464,21 +522,21 @@@ static bool try_fill_recv(struct receiv

do {
if (vi->mergeable_rx_bufs)
- err = add_recvbuf_mergeable(vi, gfp);
+ err = add_recvbuf_mergeable(rq, gfp);
else if (vi->big_packets)
- err = add_recvbuf_big(vi, gfp);
+ err = add_recvbuf_big(rq, gfp);
else
- err = add_recvbuf_small(vi, gfp);
+ err = add_recvbuf_small(rq, gfp);

oom = err == -ENOMEM;
- if (err < 0)
+ if (err)
break;
- ++vi->num;
- } while (vi->rvq->num_free);
+ ++rq->num;
- } while (err > 0);
++ } while (rq->vq->num_free);
+
- if (unlikely(vi->num > vi->max))
- vi->max = vi->num;
- virtqueue_kick(vi->rvq);
+ if (unlikely(rq->num > rq->max))
+ rq->max = rq->num;
+ virtqueue_kick(rq->vq);
return !oom;
}

@@@ -625,29 -557,13 +625,29 @@@ again
return received;
}

-static void free_old_xmit_skbs(struct virtnet_info *vi)
+static int virtnet_open(struct net_device *dev)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+ int i;
+
+ for (i = 0; i < vi->max_queue_pairs; i++) {
+ /* Make sure we have some buffers: if oom use wq. */
+ if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
+ schedule_delayed_work(&vi->refill, 0);
+ virtnet_napi_enable(&vi->rq[i]);
+ }
+
+ return 0;
+}
+
- static unsigned int free_old_xmit_skbs(struct send_queue *sq)
++static void free_old_xmit_skbs(struct send_queue *sq)
{
struct sk_buff *skb;
- unsigned int len, tot_sgs = 0;
+ unsigned int len;
+ struct virtnet_info *vi = sq->vq->vdev->priv;
struct virtnet_stats *stats = this_cpu_ptr(vi->stats);

- while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
+ while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
pr_debug("Sent skb %p\n", skb);

u64_stats_update_begin(&stats->tx_syncp);
@@@ -655,17 -571,15 +655,16 @@@
stats->tx_packets++;
u64_stats_update_end(&stats->tx_syncp);

- tot_sgs += skb_vnet_hdr(skb)->num_sg;
dev_kfree_skb_any(skb);
}
- return tot_sgs;
}

-static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
+static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
{
struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
+ unsigned num_sg;
+ struct virtnet_info *vi = sq->vq->vdev->priv;

pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);

@@@ -700,42 -614,32 +699,35 @@@

/* Encode metadata header at front. */
if (vi->mergeable_rx_bufs)
- sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr);
+ sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
else
- sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr);
+ sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);

- hdr->num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
- return virtqueue_add_buf(sq->vq, sq->sg, hdr->num_sg,
- num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1;
- return virtqueue_add_buf(vi->svq, vi->tx_sg, num_sg,
++ num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
++ return virtqueue_add_buf(sq->vq, sq->sg, num_sg,
0, skb, GFP_ATOMIC);
}

static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
+ int qnum = skb_get_queue_mapping(skb);
+ struct send_queue *sq = &vi->sq[qnum];
- int capacity;
+ int err;

/* Free up any pending old buffers before queueing new ones. */
- free_old_xmit_skbs(vi);
+ free_old_xmit_skbs(sq);

/* Try to transmit */
- capacity = xmit_skb(sq, skb);
-
- /* This can happen with OOM and indirect buffers. */
- if (unlikely(capacity < 0)) {
- if (likely(capacity == -ENOMEM)) {
- if (net_ratelimit())
- dev_warn(&dev->dev,
- "TXQ (%d) failure: out of memory\n",
- qnum);
- } else {
- dev->stats.tx_fifo_errors++;
- if (net_ratelimit())
- dev_warn(&dev->dev,
- "Unexpected TXQ (%d) failure: %d\n",
- qnum, capacity);
- }
- err = xmit_skb(vi, skb);
++ err = xmit_skb(sq, skb);
+
+ /* This should not happen! */
+ if (unlikely(err)) {
+ dev->stats.tx_fifo_errors++;
+ if (net_ratelimit())
+ dev_warn(&dev->dev,
- "Unexpected TX queue failure: %d\n", err);
++ "Unexpected TXQ (%d) failure: %d\n",
++ qnum, err);
dev->stats.tx_dropped++;
kfree_skb(skb);
return NETDEV_TX_OK;
@@@ -748,14 -652,14 +740,13 @@@

/* Apparently nice girls don't return TX_BUSY; stop the queue
* before it gets out of hand. Naturally, this wastes entries. */
- if (capacity < 2+MAX_SKB_FRAGS) {
- if (vi->svq->num_free < 2+MAX_SKB_FRAGS) {
- netif_stop_queue(dev);
- if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) {
++ if (sq->vq->num_free < 2+MAX_SKB_FRAGS) {
+ netif_stop_subqueue(dev, qnum);
+ if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
/* More just got used, free them then recheck. */
- capacity += free_old_xmit_skbs(sq);
- if (capacity >= 2+MAX_SKB_FRAGS) {
- free_old_xmit_skbs(vi);
- if (vi->svq->num_free >= 2+MAX_SKB_FRAGS) {
- netif_start_queue(dev);
- virtqueue_disable_cb(vi->svq);
++ if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
+ netif_start_subqueue(dev, qnum);
+ virtqueue_disable_cb(sq->vq);
}
}
}

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