[PATCH net-next v2 13/21] virtio_net: xsk: tx: support wakeup

Xuan Zhuo
2023-11-07T03:12:49Z

xsk wakeup is used to trigger the logic for xsk xmit by xsk framework or
user.

Virtio-net does not support to actively generate an interruption, so it
tries to trigger tx NAPI on the local cpu.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/net/virtio/main.c | 20 ++++++--------------
drivers/net/virtio/virtio_net.h | 9 +++++++++
drivers/net/virtio/xsk.c | 23 +++++++++++++++++++++++
drivers/net/virtio/xsk.h | 1 +
4 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
index ff6bc764089d..6a5e74c482f3 100644
--- a/drivers/net/virtio/main.c
+++ b/drivers/net/virtio/main.c
@@ -233,15 +233,6 @@ static void disable_delayed_refill(struct virtnet_info *vi)
spin_unlock_bh(&vi->refill_lock);
}

-static void virtqueue_napi_schedule(struct napi_struct *napi,
- struct virtqueue *vq)
-{
- if (napi_schedule_prep(napi)) {
- virtqueue_disable_cb(vq);
- __napi_schedule(napi);
- }
-}
-
static void virtqueue_napi_complete(struct napi_struct *napi,
struct virtqueue *vq, int processed)
{
@@ -250,7 +241,7 @@ static void virtqueue_napi_complete(struct napi_struct *napi,
opaque = virtqueue_enable_cb_prepare(vq);
if (napi_complete_done(napi, processed)) {
if (unlikely(virtqueue_poll(vq, opaque)))
- virtqueue_napi_schedule(napi, vq);
+ virtnet_vq_napi_schedule(napi, vq);
} else {
virtqueue_disable_cb(vq);
}
@@ -265,7 +256,7 @@ static void skb_xmit_done(struct virtqueue *vq)
virtqueue_disable_cb(vq);

if (napi->weight)
- virtqueue_napi_schedule(napi, vq);
+ virtnet_vq_napi_schedule(napi, vq);
else
/* We were probably waiting for more output buffers. */
netif_wake_subqueue(vi->dev, vq2txq(vq));
@@ -667,7 +658,7 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
netif_stop_subqueue(dev, qnum);
if (use_napi) {
if (unlikely(!virtqueue_enable_cb_delayed(sq->vq)))
- virtqueue_napi_schedule(&sq->napi, sq->vq);
+ virtnet_vq_napi_schedule(&sq->napi, sq->vq);
} else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
/* More just got used, free them then recheck. */
free_old_xmit(sq, false);
@@ -1834,7 +1825,7 @@ static void skb_recv_done(struct virtqueue *rvq)
struct virtnet_info *vi = rvq->vdev->priv;
struct virtnet_rq *rq = &vi->rq[vq2rxq(rvq)];

- virtqueue_napi_schedule(&rq->napi, rvq);
+ virtnet_vq_napi_schedule(&rq->napi, rvq);
}

static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
@@ -1846,7 +1837,7 @@ static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
* Call local_bh_enable after to trigger softIRQ processing.
*/
local_bh_disable();
- virtqueue_napi_schedule(napi, vq);
+ virtnet_vq_napi_schedule(napi, vq);
local_bh_enable();
}

@@ -3818,6 +3809,7 @@ static const struct net_device_ops virtnet_netdev = {
.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
.ndo_bpf = virtnet_xdp,
.ndo_xdp_xmit = virtnet_xdp_xmit,
+ .ndo_xsk_wakeup = virtnet_xsk_wakeup,
.ndo_features_check = passthru_features_check,
.ndo_get_phys_port_name = virtnet_get_phys_port_name,
.ndo_set_features = virtnet_set_features,
diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
index 1c21af47e13c..a431a2c1ee47 100644
--- a/drivers/net/virtio/virtio_net.h
+++ b/drivers/net/virtio/virtio_net.h
@@ -302,6 +302,15 @@ static inline bool virtnet_is_xdp_raw_buffer_queue(struct virtnet_info *vi, int
return false;
}

+static inline void virtnet_vq_napi_schedule(struct napi_struct *napi,
+ struct virtqueue *vq)
+{
+ if (napi_schedule_prep(napi)) {
+ virtqueue_disable_cb(vq);
+ __napi_schedule(napi);
+ }
+}
+
void virtnet_rx_pause(struct virtnet_info *vi, struct virtnet_rq *rq);
void virtnet_rx_resume(struct virtnet_info *vi, struct virtnet_rq *rq);
void virtnet_tx_pause(struct virtnet_info *vi, struct virtnet_sq *sq);
diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c
index caa448308232..ea5804ddd44e 100644
--- a/drivers/net/virtio/xsk.c
+++ b/drivers/net/virtio/xsk.c
@@ -117,6 +117,29 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool,
return sent == budget;
}

+int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+ struct virtnet_sq *sq;
+
+ if (!netif_running(dev))
+ return -ENETDOWN;
+
+ if (qid >= vi->curr_queue_pairs)
+ return -EINVAL;
+
+ sq = &vi->sq[qid];
+
+ if (napi_if_scheduled_mark_missed(&sq->napi))
+ return 0;
+
+ local_bh_disable();
+ virtnet_vq_napi_schedule(&sq->napi, sq->vq);
+ local_bh_enable();
+
+ return 0;
+}
+
static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct virtnet_rq *rq,
struct xsk_buff_pool *pool)
{
diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h
index 73ca8cd5308b..1bd19dcda649 100644
--- a/drivers/net/virtio/xsk.h
+++ b/drivers/net/virtio/xsk.h
@@ -17,4 +17,5 @@ static inline void *virtnet_xsk_to_ptr(u32 len)
int virtnet_xsk_pool_setup(struct net_device *dev, struct netdev_bpf *xdp);
bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool,
int budget);
+int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag);
#endif
--
2.32.0.3.g01195cf9f