[PATCH vhost v3 17/19] virtio_net: unify the code for recycling the xmit ptr

Xuan Zhuo
2024-02-29T07:21:16Z

There are two completely similar and independent implementations. This
is inconvenient for the subsequent addition of new types. So extract a
function from this piece of code and call this function uniformly to
recover old xmit ptr.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/virtio_net.c | 82 +++++++++++++++++++---------------------
1 file changed, 39 insertions(+), 43 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 140b2c155650..62f65e2cacd5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -80,6 +80,11 @@ struct virtnet_stat_desc {
size_t offset;
};

+struct virtnet_sq_free_stats {
+ u64 packets;
+ u64 bytes;
+};
+
struct virtnet_sq_stats {
struct u64_stats_sync syncp;
u64_stats_t packets;
@@ -363,6 +368,31 @@ static struct xdp_frame *ptr_to_xdp(void *ptr)
return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
}

+static void __free_old_xmit(struct send_queue *sq, bool in_napi,
+ struct virtnet_sq_free_stats *stats)
+{
+ unsigned int len;
+ void *ptr;
+
+ while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
+ ++stats->packets;
+
+ if (!is_xdp_frame(ptr)) {
+ struct sk_buff *skb = ptr;
+
+ pr_debug("Sent skb %p\n", skb);
+
+ stats->bytes += skb->len;
+ napi_consume_skb(skb, in_napi);
+ } else {
+ struct xdp_frame *frame = ptr_to_xdp(ptr);
+
+ stats->bytes += xdp_get_frame_len(frame);
+ xdp_return_frame(frame);
+ }
+ }
+}
+
/* Converting between virtqueue no. and kernel tx/rx queue no.
* 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
*/
@@ -759,37 +789,19 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)

static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
{
- unsigned int len;
- unsigned int packets = 0;
- unsigned int bytes = 0;
- void *ptr;
+ struct virtnet_sq_free_stats stats = {0};

- while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
- if (likely(!is_xdp_frame(ptr))) {
- struct sk_buff *skb = ptr;
-
- pr_debug("Sent skb %p\n", skb);
-
- bytes += skb->len;
- napi_consume_skb(skb, in_napi);
- } else {
- struct xdp_frame *frame = ptr_to_xdp(ptr);
-
- bytes += xdp_get_frame_len(frame);
- xdp_return_frame(frame);
- }
- packets++;
- }
+ __free_old_xmit(sq, in_napi, &stats);

/* Avoid overhead when no packets have been processed
* happens when called speculatively from start_xmit.
*/
- if (!packets)
+ if (!stats.packets)
return;

u64_stats_update_begin(&sq->stats.syncp);
- u64_stats_add(&sq->stats.bytes, bytes);
- u64_stats_add(&sq->stats.packets, packets);
+ u64_stats_add(&sq->stats.bytes, stats.bytes);
+ u64_stats_add(&sq->stats.packets, stats.packets);
u64_stats_update_end(&sq->stats.syncp);
}

@@ -928,15 +940,12 @@ static int virtnet_xdp_xmit(struct net_device *dev,
int n, struct xdp_frame **frames, u32 flags)
{
struct virtnet_info *vi = netdev_priv(dev);
+ struct virtnet_sq_free_stats stats = {0};
struct receive_queue *rq = vi->rq;
struct bpf_prog *xdp_prog;
struct send_queue *sq;
- unsigned int len;
- int packets = 0;
- int bytes = 0;
int nxmit = 0;
int kicks = 0;
- void *ptr;
int ret;
int i;

@@ -955,20 +964,7 @@ static int virtnet_xdp_xmit(struct net_device *dev,
}

/* Free up any pending old buffers before queueing new ones. */
- while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
- if (likely(is_xdp_frame(ptr))) {
- struct xdp_frame *frame = ptr_to_xdp(ptr);
-
- bytes += xdp_get_frame_len(frame);
- xdp_return_frame(frame);
- } else {
- struct sk_buff *skb = ptr;
-
- bytes += skb->len;
- napi_consume_skb(skb, false);
- }
- packets++;
- }
+ __free_old_xmit(sq, false, &stats);

for (i = 0; i < n; i++) {
struct xdp_frame *xdpf = frames[i];
@@ -988,8 +984,8 @@ static int virtnet_xdp_xmit(struct net_device *dev,
}
out:
u64_stats_update_begin(&sq->stats.syncp);
- u64_stats_add(&sq->stats.bytes, bytes);
- u64_stats_add(&sq->stats.packets, packets);
+ u64_stats_add(&sq->stats.bytes, stats.bytes);
+ u64_stats_add(&sq->stats.packets, stats.packets);
u64_stats_add(&sq->stats.xdp_tx, n);
u64_stats_add(&sq->stats.xdp_tx_drops, n - nxmit);
u64_stats_add(&sq->stats.kicks, kicks);
--
2.32.0.3.g01195cf9f