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Message-Id: <1581944657-13384-1-git-send-email-kda@linux-powerpc.org>
Date: Mon, 17 Feb 2020 16:04:17 +0300
From: Denis Kirjanov <kda@...ux-powerpc.org>
To: netdev@...r.kernel.org
Cc: Denis Kirjanov <kda@...ux-powerpc.org>
Subject: [PATCH net-next] xen-netfront: add basic XDP support
the patch adds a basic xdp logic to the netfront driver
Signed-off-by: Denis Kirjanov <kda@...ux-powerpc.org>
---
drivers/net/xen-netfront.c | 125 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 125 insertions(+)
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 482c6c8..06dd088 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -44,6 +44,8 @@
#include <linux/mm.h>
#include <linux/slab.h>
#include <net/ip.h>
+#include <linux/bpf.h>
+#include <linux/bpf_trace.h>
#include <xen/xen.h>
#include <xen/xenbus.h>
@@ -102,6 +104,8 @@ struct netfront_queue {
char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
struct netfront_info *info;
+ struct bpf_prog __rcu *xdp_prog;
+
struct napi_struct napi;
/* Split event channels support, tx_* == rx_* when using
@@ -778,6 +782,53 @@ static int xennet_get_extras(struct netfront_queue *queue,
return err;
}
+u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata,
+ struct xen_netif_rx_response *rx, struct bpf_prog *prog,
+ struct xdp_buff *xdp)
+{
+ void *data = page_address(pdata);
+ u32 len = rx->status;
+ struct page *page = NULL;
+ u32 act = XDP_PASS;
+
+ page = alloc_page(GFP_ATOMIC);
+ if (!page) {
+ act = XDP_DROP;
+ goto out;
+ }
+
+ xdp->data_hard_start = page_address(page);
+ xdp->data = xdp->data_hard_start + 256;
+ xdp_set_data_meta_invalid(xdp);
+ xdp->data_end = xdp->data + len;
+ xdp->handle = 0;
+
+ memcpy(xdp->data, data, len);
+
+ act = bpf_prog_run_xdp(prog, xdp);
+ switch (act) {
+ case XDP_PASS:
+ case XDP_TX:
+ case XDP_DROP:
+ break;
+
+ case XDP_ABORTED:
+ trace_xdp_exception(queue->info->netdev, prog, act);
+ break;
+
+ default:
+ bpf_warn_invalid_xdp_action(act);
+ }
+
+out:
+ if (page && act != XDP_PASS && act != XDP_TX) {
+ __free_page(page);
+ xdp->data_hard_start = NULL;
+ }
+
+ return act;
+}
+
static int xennet_get_responses(struct netfront_queue *queue,
struct netfront_rx_info *rinfo, RING_IDX rp,
struct sk_buff_head *list)
@@ -792,6 +843,9 @@ static int xennet_get_responses(struct netfront_queue *queue,
int slots = 1;
int err = 0;
unsigned long ret;
+ struct bpf_prog *xdp_prog;
+ struct xdp_buff xdp;
+ u32 verdict;
if (rx->flags & XEN_NETRXF_extra_info) {
err = xennet_get_extras(queue, extras, rp);
@@ -827,6 +881,21 @@ static int xennet_get_responses(struct netfront_queue *queue,
gnttab_release_grant_reference(&queue->gref_rx_head, ref);
+ rcu_read_lock();
+ xdp_prog = rcu_dereference(queue->xdp_prog);
+ if (xdp_prog) {
+ WARN_ON_ONCE(skb_shinfo(skb)->nr_frags != 1);
+ verdict = xennet_run_xdp(queue,
+ skb_frag_page(&skb_shinfo(skb)->frags[0]),
+ rx, xdp_prog, &xdp);
+
+ if (verdict != XDP_PASS && verdict != XDP_TX) {
+ err = -EINVAL;
+ goto next;
+ }
+
+ }
+ rcu_read_unlock();
__skb_queue_tail(list, skb);
next:
@@ -1261,6 +1330,61 @@ static void xennet_poll_controller(struct net_device *dev)
}
#endif
+static int xennet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
+ struct netlink_ext_ack *extack)
+{
+ struct netfront_info *np = netdev_priv(dev);
+ struct bpf_prog *old_prog;
+ unsigned int i;
+
+ old_prog = rtnl_dereference(np->queues[0].xdp_prog);
+ if (!old_prog && !prog)
+ return 0;
+
+ if (prog)
+ bpf_prog_add(prog, dev->real_num_tx_queues);
+
+ for (i = 0; i < dev->real_num_tx_queues; ++i)
+ rcu_assign_pointer(np->queues[i].xdp_prog, prog);
+
+ if (old_prog)
+ for (i = 0; i < dev->real_num_tx_queues; ++i)
+ bpf_prog_put(old_prog);
+
+ return 0;
+}
+
+static u32 xennet_xdp_query(struct net_device *dev)
+{
+ struct netfront_info *np = netdev_priv(dev);
+ unsigned int num_queues = dev->real_num_tx_queues;
+ unsigned int i;
+ struct netfront_queue *queue;
+ const struct bpf_prog *xdp_prog;
+
+ for (i = 0; i < num_queues; ++i) {
+ queue = &np->queues[i];
+ xdp_prog = rtnl_dereference(queue->xdp_prog);
+ if (xdp_prog)
+ return xdp_prog->aux->id;
+ }
+
+ return 0;
+}
+
+static int xennet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
+{
+ switch (xdp->command) {
+ case XDP_SETUP_PROG:
+ return xennet_xdp_set(dev, xdp->prog, xdp->extack);
+ case XDP_QUERY_PROG:
+ xdp->prog_id = xennet_xdp_query(dev);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
static const struct net_device_ops xennet_netdev_ops = {
.ndo_open = xennet_open,
.ndo_stop = xennet_close,
@@ -1272,6 +1396,7 @@ static void xennet_poll_controller(struct net_device *dev)
.ndo_fix_features = xennet_fix_features,
.ndo_set_features = xennet_set_features,
.ndo_select_queue = xennet_select_queue,
+ .ndo_bpf = xennet_xdp,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = xennet_poll_controller,
#endif
--
1.8.3.1
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