Commit 1c9535c7 authored by Denis Kirjanov's avatar Denis Kirjanov Committed by David S. Miller
Browse files

xen networking: add XDP offset adjustment to xen-netback 



the patch basically adds the offset adjustment and netfront
state reading to make XDP work on netfront side.

Reviewed-by: default avatarPaul Durrant <paul@xen.org>
Signed-off-by: default avatarDenis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6c5aa6fc

drivers/net/xen-netback/common.h

+4 −0
Original line number Diff line number Diff line
@@ -281,6 +281,9 @@ struct xenvif { 
	u8 ipv6_csum:1;

	u8 multicast_control:1;



	/* headroom requested by xen-netfront */

	u16 xdp_headroom;



	/* Is this interface disabled? True when backend discovers

	 * frontend is rogue.

	 */
@@ -395,6 +398,7 @@ static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue) 
irqreturn_t xenvif_interrupt(int irq, void *dev_id);



extern bool separate_tx_rx_irq;

extern bool provides_xdp_headroom;



extern unsigned int rx_drain_timeout_msecs;

extern unsigned int rx_stall_timeout_msecs;

drivers/net/xen-netback/interface.c

+2 −0
Original line number Diff line number Diff line
@@ -483,6 +483,8 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, 
	vif->queues = NULL;

	vif->num_queues = 0;



	vif->xdp_headroom = 0;



	spin_lock_init(&vif->lock);

	INIT_LIST_HEAD(&vif->fe_mcast_addr);

drivers/net/xen-netback/netback.c

+7 −0
Original line number Diff line number Diff line
@@ -96,6 +96,13 @@ unsigned int xenvif_hash_cache_size = XENVIF_HASH_CACHE_SIZE_DEFAULT; 
module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);

MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");



/* The module parameter tells that we have to put data

 * for xen-netfront with the XDP_PACKET_HEADROOM offset

 * needed for XDP processing

 */

bool provides_xdp_headroom = true;

module_param(provides_xdp_headroom, bool, 0644);



static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,

			       u8 status);

drivers/net/xen-netback/rx.c

+14 −1
Original line number Diff line number Diff line
@@ -258,6 +258,19 @@ static void xenvif_rx_next_skb(struct xenvif_queue *queue, 
		pkt->extra_count++;

	}



	if (queue->vif->xdp_headroom) {

		struct xen_netif_extra_info *extra;



		extra = &pkt->extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];



		memset(extra, 0, sizeof(struct xen_netif_extra_info));

		extra->u.xdp.headroom = queue->vif->xdp_headroom;

		extra->type = XEN_NETIF_EXTRA_TYPE_XDP;

		extra->flags = 0;



		pkt->extra_count++;

	}



	if (skb->sw_hash) {

		struct xen_netif_extra_info *extra;
@@ -356,7 +369,7 @@ static void xenvif_rx_data_slot(struct xenvif_queue *queue, 
				struct xen_netif_rx_request *req,

				struct xen_netif_rx_response *rsp)

{

	unsigned int offset = 0;

	unsigned int offset = queue->vif->xdp_headroom;

	unsigned int flags;



	do {

drivers/net/xen-netback/xenbus.c

+34 −0
Original line number Diff line number Diff line
@@ -393,6 +393,24 @@ static void set_backend_state(struct backend_info *be, 
	}

}



static void read_xenbus_frontend_xdp(struct backend_info *be,

				      struct xenbus_device *dev)

{

	struct xenvif *vif = be->vif;

	u16 headroom;

	int err;



	err = xenbus_scanf(XBT_NIL, dev->otherend,

			   "xdp-headroom", "%hu", &headroom);

	if (err != 1) {

		vif->xdp_headroom = 0;

		return;

	}

	if (headroom > XEN_NETIF_MAX_XDP_HEADROOM)

		headroom = XEN_NETIF_MAX_XDP_HEADROOM;

	vif->xdp_headroom = headroom;

}



/**

 * Callback received when the frontend's state changes.

 */
@@ -417,6 +435,11 @@ static void frontend_changed(struct xenbus_device *dev, 
		set_backend_state(be, XenbusStateConnected);

		break;



	case XenbusStateReconfiguring:

		read_xenbus_frontend_xdp(be, dev);

		xenbus_switch_state(dev, XenbusStateReconfigured);

		break;



	case XenbusStateClosing:

		set_backend_state(be, XenbusStateClosing);

		break;
@@ -947,6 +970,8 @@ static int read_xenbus_vif_flags(struct backend_info *be) 
	vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,

						"feature-ipv6-csum-offload", 0);



	read_xenbus_frontend_xdp(be, dev);



	return 0;

}
@@ -1036,6 +1061,15 @@ static int netback_probe(struct xenbus_device *dev, 
			goto abort_transaction;

		}



		/* we can adjust a headroom for netfront XDP processing */

		err = xenbus_printf(xbt, dev->nodename,

				    "feature-xdp-headroom", "%d",

				    provides_xdp_headroom);

		if (err) {

			message = "writing feature-xdp-headroom";

			goto abort_transaction;

		}



		/* We don't support rx-flip path (except old guests who

		 * don't grok this feature flag).

		 */

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