[PATCH net-next v2 09/21] virtio_net: xsk: bind/unbind xsk

Xuan Zhuo
2023-11-07T03:12:46Z

This patch implement the logic of bind/unbind xsk pool to sq and rq.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/net/virtio/Makefile | 2 +-
drivers/net/virtio/main.c | 11 +-
drivers/net/virtio/virtio_net.h | 16 +++
drivers/net/virtio/xsk.c | 187 ++++++++++++++++++++++++++++++++
drivers/net/virtio/xsk.h | 7 ++
5 files changed, 216 insertions(+), 7 deletions(-)
create mode 100644 drivers/net/virtio/xsk.c
create mode 100644 drivers/net/virtio/xsk.h

diff --git a/drivers/net/virtio/Makefile b/drivers/net/virtio/Makefile
index 15ed7c97fd4f..8c2a884d2dba 100644
--- a/drivers/net/virtio/Makefile
+++ b/drivers/net/virtio/Makefile
@@ -5,4 +5,4 @@

obj-$(CONFIG_VIRTIO_NET) += virtio_net.o

-virtio_net-y := main.o
+virtio_net-y := main.o xsk.o
diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
index f052db459156..c4601784b6d1 100644
--- a/drivers/net/virtio/main.c
+++ b/drivers/net/virtio/main.c
@@ -8,7 +8,6 @@
#include <linux/etherdevice.h>
#include <linux/module.h>
#include <linux/virtio.h>
-#include <linux/virtio_net.h>
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <linux/scatterlist.h>
@@ -23,6 +22,7 @@
#include <net/netdev_rx_queue.h>

#include "virtio_net.h"
+#include "xsk.h"

static int napi_weight = NAPI_POLL_WEIGHT;
module_param(napi_weight, int, 0444);
@@ -150,9 +150,6 @@ struct virtio_net_common_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)
{
return (unsigned long)ptr & VIRTIO_XDP_FLAG;
@@ -3797,6 +3794,8 @@ static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
switch (xdp->command) {
case XDP_SETUP_PROG:
return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
+ case XDP_SETUP_XSK_POOL:
+ return virtnet_xsk_pool_setup(dev, xdp);
default:
return -EINVAL;
}
@@ -3982,7 +3981,7 @@ static void free_receive_page_frags(struct virtnet_info *vi)
}
}

-static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
+void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
{
struct virtnet_info *vi = vq->vdev->priv;
struct virtnet_sq *sq;
@@ -4003,7 +4002,7 @@ static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
}
}

-static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf)
+void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf)
{
struct virtnet_info *vi = vq->vdev->priv;
struct virtnet_rq *rq;
diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
index ce806afb6d64..98ba23cfdb20 100644
--- a/drivers/net/virtio/virtio_net.h
+++ b/drivers/net/virtio/virtio_net.h
@@ -5,6 +5,8 @@

#include <linux/ethtool.h>
#include <linux/average.h>
+#include <linux/virtio_net.h>
+#include <net/xdp_sock_drv.h>

/* RX packet size EWMA. The average packet size is used to determine the packet
* buffer size when refilling RX rings. As the entire RX ring may be refilled
@@ -83,6 +85,11 @@ struct virtnet_sq {
bool do_dma;

struct virtnet_sq_dma_head dmainfo;
+ struct {
+ struct xsk_buff_pool *pool;
+
+ dma_addr_t hdr_dma_address;
+ } xsk;
};

/* Internal representation of a receive virtqueue */
@@ -123,6 +130,13 @@ struct virtnet_rq {

/* Do dma by self */
bool do_dma;
+
+ struct {
+ struct xsk_buff_pool *pool;
+
+ /* xdp rxq used by xsk */
+ struct xdp_rxq_info xdp_rxq;
+ } xsk;
};

struct virtnet_info {
@@ -211,4 +225,6 @@ 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);
void virtnet_tx_resume(struct virtnet_info *vi, struct virtnet_sq *sq);
+void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
+void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf);
#endif
diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c
new file mode 100644
index 000000000000..8b397787603f
--- /dev/null
+++ b/drivers/net/virtio/xsk.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * virtio-net xsk
+ */
+
+#include "virtio_net.h"
+
+static struct virtio_net_hdr_mrg_rxbuf xsk_hdr;
+
+static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct virtnet_rq *rq,
+ struct xsk_buff_pool *pool)
+{
+ int err, qindex;
+
+ qindex = rq - vi->rq;
+
+ if (pool) {
+ err = xdp_rxq_info_reg(&rq->xsk.xdp_rxq, vi->dev, qindex, rq->napi.napi_id);
+ if (err < 0)
+ return err;
+
+ err = xdp_rxq_info_reg_mem_model(&rq->xsk.xdp_rxq,
+ MEM_TYPE_XSK_BUFF_POOL, NULL);
+ if (err < 0) {
+ xdp_rxq_info_unreg(&rq->xsk.xdp_rxq);
+ return err;
+ }
+
+ xsk_pool_set_rxq_info(pool, &rq->xsk.xdp_rxq);
+ }
+
+ virtnet_rx_pause(vi, rq);
+
+ err = virtqueue_reset(rq->vq, virtnet_rq_free_unused_buf);
+ if (err) {
+ netdev_err(vi->dev, "reset rx fail: rx queue index: %d err: %d\n", qindex, err);
+
+ pool = NULL;
+ }
+
+ if (!pool)
+ xdp_rxq_info_unreg(&rq->xsk.xdp_rxq);
+
+ rq->xsk.pool = pool;
+
+ virtnet_rx_resume(vi, rq);
+
+ return err;
+}
+
+static int virtnet_sq_bind_xsk_pool(struct virtnet_info *vi,
+ struct virtnet_sq *sq,
+ struct xsk_buff_pool *pool)
+{
+ int err, qindex;
+
+ qindex = sq - vi->sq;
+
+ virtnet_tx_pause(vi, sq);
+
+ err = virtqueue_reset(sq->vq, virtnet_sq_free_unused_buf);
+ if (err) {
+ pool = NULL;
+ netdev_err(vi->dev, "reset tx fail: tx queue index: %d err: %d\n", qindex, err);
+ }
+
+ sq->xsk.pool = pool;
+
+ virtnet_tx_resume(vi, sq);
+
+ return err;
+}
+
+static int virtnet_xsk_pool_enable(struct net_device *dev,
+ struct xsk_buff_pool *pool,
+ u16 qid)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+ struct virtnet_rq *rq;
+ struct virtnet_sq *sq;
+ struct device *dma_dev;
+ dma_addr_t hdr_dma;
+ int err;
+
+ /* In big_packets mode, xdp cannot work, so there is no need to
+ * initialize xsk of rq.
+ */
+ if (vi->big_packets && !vi->mergeable_rx_bufs)
+ return -ENOENT;
+
+ if (qid >= vi->curr_queue_pairs)
+ return -EINVAL;
+
+ sq = &vi->sq[qid];
+ rq = &vi->rq[qid];
+
+ /* xsk tx zerocopy depend on the tx napi.
+ *
+ * All xsk packets are actually consumed and sent out from the xsk tx
+ * queue under the tx napi mechanism.
+ */
+ if (!sq->napi.weight)
+ return -EPERM;
+
+ if (!rq->do_dma || !sq->do_dma)
+ return -EPERM;
+
+ /* For the xsk, the tx and rx should have the same device. But
+ * vq->dma_dev allows every vq has the respective dma dev. So I check
+ * the dma dev of vq and sq is the same dev.
+ */
+ if (virtqueue_dma_dev(rq->vq) != virtqueue_dma_dev(sq->vq))
+ return -EPERM;
+
+ dma_dev = virtqueue_dma_dev(rq->vq);
+ if (!dma_dev)
+ return -EPERM;
+
+ 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;
+
+ err = xsk_pool_dma_map(pool, dma_dev, 0);
+ if (err)
+ goto err_xsk_map;
+
+ err = virtnet_rq_bind_xsk_pool(vi, rq, pool);
+ if (err)
+ goto err_rq;
+
+ err = virtnet_sq_bind_xsk_pool(vi, sq, pool);
+ if (err)
+ goto err_sq;
+
+ /* Now, we do not support tx offset, so all the tx virtnet hdr is zero.
+ * So all the tx packets can share a single hdr.
+ */
+ sq->xsk.hdr_dma_address = hdr_dma;
+
+ return 0;
+
+err_sq:
+ virtnet_rq_bind_xsk_pool(vi, rq, NULL);
+err_rq:
+ xsk_pool_dma_unmap(pool, 0);
+err_xsk_map:
+ dma_unmap_single(dma_dev, hdr_dma, vi->hdr_len, DMA_TO_DEVICE);
+ return err;
+}
+
+static int virtnet_xsk_pool_disable(struct net_device *dev, u16 qid)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+ struct xsk_buff_pool *pool;
+ struct device *dma_dev;
+ struct virtnet_rq *rq;
+ struct virtnet_sq *sq;
+ int err1, err2;
+
+ if (qid >= vi->curr_queue_pairs)
+ return -EINVAL;
+
+ sq = &vi->sq[qid];
+ rq = &vi->rq[qid];
+
+ pool = sq->xsk.pool;
+
+ err1 = virtnet_sq_bind_xsk_pool(vi, sq, NULL);
+ err2 = virtnet_rq_bind_xsk_pool(vi, rq, NULL);
+
+ xsk_pool_dma_unmap(pool, 0);
+
+ dma_dev = virtqueue_dma_dev(rq->vq);
+
+ dma_unmap_single(dma_dev, sq->xsk.hdr_dma_address, vi->hdr_len, DMA_TO_DEVICE);
+
+ return err1 | err2;
+}
+
+int virtnet_xsk_pool_setup(struct net_device *dev, struct netdev_bpf *xdp)
+{
+ if (xdp->xsk.pool)
+ return virtnet_xsk_pool_enable(dev, xdp->xsk.pool,
+ xdp->xsk.queue_id);
+ else
+ return virtnet_xsk_pool_disable(dev, xdp->xsk.queue_id);
+}
diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h
new file mode 100644
index 000000000000..1918285c310c
--- /dev/null
+++ b/drivers/net/virtio/xsk.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __XSK_H__
+#define __XSK_H__
+
+int virtnet_xsk_pool_setup(struct net_device *dev, struct netdev_bpf *xdp);
+#endif
--
2.32.0.3.g01195cf9f