Re: [PATCH net-next v1 15/19] virtio_net: xsk: rx: introduce add_recvbuf_xsk()
On Fri, 20 Oct 2023 14:56:51 +0800, Jason Wang wrote:
> On Mon, Oct 16, 2023 at 8:01 PM Xuan Zhuo wrote:
> >
> > Implement the logic of filling vq with XSK buffer.
> >
> > Signed-off-by: Xuan Zhuo
> > ---
> > drivers/net/virtio/main.c | 13 +++
> > drivers/net/virtio/virtio_net.h | 5 +++
> > drivers/net/virtio/xsk.c| 66 -
> > drivers/net/virtio/xsk.h| 2 +
> > 4 files changed, 85 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
> > index 58bb38f9b453..0e740447b142 100644
> > --- a/drivers/net/virtio/main.c
> > +++ b/drivers/net/virtio/main.c
> > @@ -1787,9 +1787,20 @@ static int add_recvbuf_mergeable(struct virtnet_info
> > *vi,
> > static bool try_fill_recv(struct virtnet_info *vi, struct virtnet_rq *rq,
> > gfp_t gfp)
> > {
> > + struct xsk_buff_pool *pool;
> > int err;
> > bool oom;
> >
> > + rcu_read_lock();
>
> A question here: should we sync with refill work during rx_pause?
>
> > + pool = rcu_dereference(rq->xsk.pool);
> > + if (pool) {
> > + err = virtnet_add_recvbuf_xsk(vi, rq, pool, gfp);
> > + oom = err == -ENOMEM;
> > + rcu_read_unlock();
> > + goto kick;
> > + }
> > + rcu_read_unlock();
>
> And if we synchronize with that there's probably no need for the rcu
> and we can merge the logic with the following ones?
YES. we synchronize the rx_pause and this.
But for the rcu object, I think we should use rcu_xxx() API.
Thanks.
>
> Thanks
>
>
> > +
> > do {
> > if (vi->mergeable_rx_bufs)
> > err = add_recvbuf_mergeable(vi, rq, gfp);
> > @@ -1802,6 +1813,8 @@ static bool try_fill_recv(struct virtnet_info *vi,
> > struct virtnet_rq *rq,
> > if (err)
> > break;
> > } while (rq->vq->num_free);
> > +
> > +kick:
> > if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
> > unsigned long flags;
> >
> > diff --git a/drivers/net/virtio/virtio_net.h
> > b/drivers/net/virtio/virtio_net.h
> > index d4e620a084f4..6e71622fca45 100644
> > --- a/drivers/net/virtio/virtio_net.h
> > +++ b/drivers/net/virtio/virtio_net.h
> > @@ -156,6 +156,11 @@ struct virtnet_rq {
> >
> > /* xdp rxq used by xsk */
> > struct xdp_rxq_info xdp_rxq;
> > +
> > + struct xdp_buff **xsk_buffs;
> > + u32 nxt_idx;
> > + u32 num;
> > + u32 size;
> > } xsk;
> > };
> >
> > diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c
> > index 973e783260c3..841fb078882a 100644
> > --- a/drivers/net/virtio/xsk.c
> > +++ b/drivers/net/virtio/xsk.c
> > @@ -37,6 +37,58 @@ static void virtnet_xsk_check_queue(struct virtnet_sq
> > *sq)
> > netif_stop_subqueue(dev, qnum);
> > }
> >
> > +static int virtnet_add_recvbuf_batch(struct virtnet_info *vi, struct
> > virtnet_rq *rq,
> > +struct xsk_buff_pool *pool, gfp_t gfp)
> > +{
> > + struct xdp_buff **xsk_buffs;
> > + dma_addr_t addr;
> > + u32 len, i;
> > + int err = 0;
> > +
> > + xsk_buffs = rq->xsk.xsk_buffs;
> > +
> > + if (rq->xsk.nxt_idx >= rq->xsk.num) {
> > + rq->xsk.num = xsk_buff_alloc_batch(pool, xsk_buffs,
> > rq->xsk.size);
> > + if (!rq->xsk.num)
> > + return -ENOMEM;
> > + rq->xsk.nxt_idx = 0;
> > + }
> > +
> > + while (rq->xsk.nxt_idx < rq->xsk.num) {
> > + i = rq->xsk.nxt_idx;
> > +
> > + /* use the part of XDP_PACKET_HEADROOM as the virtnet hdr
> > space */
> > + addr = xsk_buff_xdp_get_dma(xsk_buffs[i]) - vi->hdr_len;
> > + len = xsk_pool_get_rx_frame_size(pool) + vi->hdr_len;
> > +
> > + sg_init_table(rq->sg, 1);
> > + sg_fill_dma(rq->sg, addr, len);
> > +
> > + err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, xsk_buffs[i],
> > gfp);
> > + if (err)
> > + return err;
> > +
> > + rq->xsk.nxt_idx++;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct virtnet_rq *rq,
> > + struct xsk_buff_pool *pool, gfp_t gfp)
> > +{
> > + int err;
> > +
> > + do {
> > + err = virtnet_add_recvbuf_batch(vi, rq, pool, gfp);
> > + if (err)
> > + return err;
> > +
> > + } while (rq->vq->num_free);
> > +
> > + return 0;
> > +}
> > +
> > static int virtnet_xsk_xmit_one(struct virtnet_sq *sq,
> > struct xsk_buff_pool *pool,
> > struct xdp_desc *desc)
> > @@ -244,7 +296,7 @@ static int vir
Re: [PATCH net-next v1 15/19] virtio_net: xsk: rx: introduce add_recvbuf_xsk()
On Mon, Oct 16, 2023 at 8:01 PM Xuan Zhuo wrote:
>
> Implement the logic of filling vq with XSK buffer.
>
> Signed-off-by: Xuan Zhuo
> ---
> drivers/net/virtio/main.c | 13 +++
> drivers/net/virtio/virtio_net.h | 5 +++
> drivers/net/virtio/xsk.c| 66 -
> drivers/net/virtio/xsk.h| 2 +
> 4 files changed, 85 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
> index 58bb38f9b453..0e740447b142 100644
> --- a/drivers/net/virtio/main.c
> +++ b/drivers/net/virtio/main.c
> @@ -1787,9 +1787,20 @@ static int add_recvbuf_mergeable(struct virtnet_info
> *vi,
> static bool try_fill_recv(struct virtnet_info *vi, struct virtnet_rq *rq,
> gfp_t gfp)
> {
> + struct xsk_buff_pool *pool;
> int err;
> bool oom;
>
> + rcu_read_lock();
A question here: should we sync with refill work during rx_pause?
> + pool = rcu_dereference(rq->xsk.pool);
> + if (pool) {
> + err = virtnet_add_recvbuf_xsk(vi, rq, pool, gfp);
> + oom = err == -ENOMEM;
> + rcu_read_unlock();
> + goto kick;
> + }
> + rcu_read_unlock();
And if we synchronize with that there's probably no need for the rcu
and we can merge the logic with the following ones?
Thanks
> +
> do {
> if (vi->mergeable_rx_bufs)
> err = add_recvbuf_mergeable(vi, rq, gfp);
> @@ -1802,6 +1813,8 @@ static bool try_fill_recv(struct virtnet_info *vi,
> struct virtnet_rq *rq,
> if (err)
> break;
> } while (rq->vq->num_free);
> +
> +kick:
> if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
> unsigned long flags;
>
> diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
> index d4e620a084f4..6e71622fca45 100644
> --- a/drivers/net/virtio/virtio_net.h
> +++ b/drivers/net/virtio/virtio_net.h
> @@ -156,6 +156,11 @@ struct virtnet_rq {
>
> /* xdp rxq used by xsk */
> struct xdp_rxq_info xdp_rxq;
> +
> + struct xdp_buff **xsk_buffs;
> + u32 nxt_idx;
> + u32 num;
> + u32 size;
> } xsk;
> };
>
> diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c
> index 973e783260c3..841fb078882a 100644
> --- a/drivers/net/virtio/xsk.c
> +++ b/drivers/net/virtio/xsk.c
> @@ -37,6 +37,58 @@ static void virtnet_xsk_check_queue(struct virtnet_sq *sq)
> netif_stop_subqueue(dev, qnum);
> }
>
> +static int virtnet_add_recvbuf_batch(struct virtnet_info *vi, struct
> virtnet_rq *rq,
> +struct xsk_buff_pool *pool, gfp_t gfp)
> +{
> + struct xdp_buff **xsk_buffs;
> + dma_addr_t addr;
> + u32 len, i;
> + int err = 0;
> +
> + xsk_buffs = rq->xsk.xsk_buffs;
> +
> + if (rq->xsk.nxt_idx >= rq->xsk.num) {
> + rq->xsk.num = xsk_buff_alloc_batch(pool, xsk_buffs,
> rq->xsk.size);
> + if (!rq->xsk.num)
> + return -ENOMEM;
> + rq->xsk.nxt_idx = 0;
> + }
> +
> + while (rq->xsk.nxt_idx < rq->xsk.num) {
> + i = rq->xsk.nxt_idx;
> +
> + /* use the part of XDP_PACKET_HEADROOM as the virtnet hdr
> space */
> + addr = xsk_buff_xdp_get_dma(xsk_buffs[i]) - vi->hdr_len;
> + len = xsk_pool_get_rx_frame_size(pool) + vi->hdr_len;
> +
> + sg_init_table(rq->sg, 1);
> + sg_fill_dma(rq->sg, addr, len);
> +
> + err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, xsk_buffs[i],
> gfp);
> + if (err)
> + return err;
> +
> + rq->xsk.nxt_idx++;
> + }
> +
> + return 0;
> +}
> +
> +int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct virtnet_rq *rq,
> + struct xsk_buff_pool *pool, gfp_t gfp)
> +{
> + int err;
> +
> + do {
> + err = virtnet_add_recvbuf_batch(vi, rq, pool, gfp);
> + if (err)
> + return err;
> +
> + } while (rq->vq->num_free);
> +
> + return 0;
> +}
> +
> static int virtnet_xsk_xmit_one(struct virtnet_sq *sq,
> struct xsk_buff_pool *pool,
> struct xdp_desc *desc)
> @@ -244,7 +296,7 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
> struct virtnet_sq *sq;
> struct device *dma_dev;
> dma_addr_t hdr_dma;
> - int err;
> + int err, size;
>
> /* In big_packets mode, xdp cannot work, so there is no need to
> * initialize xsk of rq.
> @@ -276,6 +328,16 @@ static int virtnet_xsk_pool_enable(struct net_device
> *dev,
> if (!dma_dev)
> return -EPERM;
>
> + size = vir
[PATCH net-next v1 15/19] virtio_net: xsk: rx: introduce add_recvbuf_xsk()
Implement the logic of filling vq with XSK buffer.
Signed-off-by: Xuan Zhuo
---
drivers/net/virtio/main.c | 13 +++
drivers/net/virtio/virtio_net.h | 5 +++
drivers/net/virtio/xsk.c| 66 -
drivers/net/virtio/xsk.h| 2 +
4 files changed, 85 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
index 58bb38f9b453..0e740447b142 100644
--- a/drivers/net/virtio/main.c
+++ b/drivers/net/virtio/main.c
@@ -1787,9 +1787,20 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi,
static bool try_fill_recv(struct virtnet_info *vi, struct virtnet_rq *rq,
gfp_t gfp)
{
+ struct xsk_buff_pool *pool;
int err;
bool oom;
+ rcu_read_lock();
+ pool = rcu_dereference(rq->xsk.pool);
+ if (pool) {
+ err = virtnet_add_recvbuf_xsk(vi, rq, pool, gfp);
+ oom = err == -ENOMEM;
+ rcu_read_unlock();
+ goto kick;
+ }
+ rcu_read_unlock();
+
do {
if (vi->mergeable_rx_bufs)
err = add_recvbuf_mergeable(vi, rq, gfp);
@@ -1802,6 +1813,8 @@ static bool try_fill_recv(struct virtnet_info *vi, struct
virtnet_rq *rq,
if (err)
break;
} while (rq->vq->num_free);
+
+kick:
if (virtqueue_kick_prepare(rq->vq) && virtqueue_notify(rq->vq)) {
unsigned long flags;
diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
index d4e620a084f4..6e71622fca45 100644
--- a/drivers/net/virtio/virtio_net.h
+++ b/drivers/net/virtio/virtio_net.h
@@ -156,6 +156,11 @@ struct virtnet_rq {
/* xdp rxq used by xsk */
struct xdp_rxq_info xdp_rxq;
+
+ struct xdp_buff **xsk_buffs;
+ u32 nxt_idx;
+ u32 num;
+ u32 size;
} xsk;
};
diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c
index 973e783260c3..841fb078882a 100644
--- a/drivers/net/virtio/xsk.c
+++ b/drivers/net/virtio/xsk.c
@@ -37,6 +37,58 @@ static void virtnet_xsk_check_queue(struct virtnet_sq *sq)
netif_stop_subqueue(dev, qnum);
}
+static int virtnet_add_recvbuf_batch(struct virtnet_info *vi, struct
virtnet_rq *rq,
+struct xsk_buff_pool *pool, gfp_t gfp)
+{
+ struct xdp_buff **xsk_buffs;
+ dma_addr_t addr;
+ u32 len, i;
+ int err = 0;
+
+ xsk_buffs = rq->xsk.xsk_buffs;
+
+ if (rq->xsk.nxt_idx >= rq->xsk.num) {
+ rq->xsk.num = xsk_buff_alloc_batch(pool, xsk_buffs,
rq->xsk.size);
+ if (!rq->xsk.num)
+ return -ENOMEM;
+ rq->xsk.nxt_idx = 0;
+ }
+
+ while (rq->xsk.nxt_idx < rq->xsk.num) {
+ i = rq->xsk.nxt_idx;
+
+ /* use the part of XDP_PACKET_HEADROOM as the virtnet hdr space
*/
+ addr = xsk_buff_xdp_get_dma(xsk_buffs[i]) - vi->hdr_len;
+ len = xsk_pool_get_rx_frame_size(pool) + vi->hdr_len;
+
+ sg_init_table(rq->sg, 1);
+ sg_fill_dma(rq->sg, addr, len);
+
+ err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, xsk_buffs[i], gfp);
+ if (err)
+ return err;
+
+ rq->xsk.nxt_idx++;
+ }
+
+ return 0;
+}
+
+int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct virtnet_rq *rq,
+ struct xsk_buff_pool *pool, gfp_t gfp)
+{
+ int err;
+
+ do {
+ err = virtnet_add_recvbuf_batch(vi, rq, pool, gfp);
+ if (err)
+ return err;
+
+ } while (rq->vq->num_free);
+
+ return 0;
+}
+
static int virtnet_xsk_xmit_one(struct virtnet_sq *sq,
struct xsk_buff_pool *pool,
struct xdp_desc *desc)
@@ -244,7 +296,7 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
struct virtnet_sq *sq;
struct device *dma_dev;
dma_addr_t hdr_dma;
- int err;
+ int err, size;
/* In big_packets mode, xdp cannot work, so there is no need to
* initialize xsk of rq.
@@ -276,6 +328,16 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
if (!dma_dev)
return -EPERM;
+ size = virtqueue_get_vring_size(rq->vq);
+
+ rq->xsk.xsk_buffs = kcalloc(size, sizeof(*rq->xsk.xsk_buffs),
GFP_KERNEL);
+ if (!rq->xsk.xsk_buffs)
+ return -ENOMEM;
+
+ rq->xsk.size = size;
+ rq->xsk.nxt_idx = 0;
+ rq->xsk.num = 0;
+
hdr_dma = dma_map_single(dma_dev, &xsk_hdr, vi->hdr_len, DMA_TO_DEVICE);
if (dma_mapping_error(dma_dev, hdr_dma))
return -ENOMEM;
@@ -338,6 +400,8 @@ static int virtnet_xsk_pool_disable(struct net_device *dev,
u16 qid)
