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Commit f07f9893 authored by Paul Durrant's avatar Paul Durrant Committed by David S. Miller
Browse files

xen-netback: pass hash value to the frontend 



My recent patch to include/xen/interface/io/netif.h defines a new extra
info type that can be used to pass hash values between backend and guest
frontend.

This patch adds code to xen-netback to pass hash values calculated for
guest receive-side packets (i.e. netback transmit side) to the frontend.

Signed-off-by: default avatarPaul Durrant <paul.durrant@citrix.com>
Acked-by: default avatarWei Liu <wei.liu2@citrix.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 40d8abde

drivers/net/xen-netback/interface.c

+11 −2
Original line number Diff line number Diff line
@@ -158,8 +158,17 @@ static u16 xenvif_select_queue(struct net_device *dev, struct sk_buff *skb, 
	struct xenvif *vif = netdev_priv(dev);

	unsigned int size = vif->hash.size;



	if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE)

		return fallback(dev, skb) % dev->real_num_tx_queues;

	if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) {

		u16 index = fallback(dev, skb) % dev->real_num_tx_queues;



		/* Make sure there is no hash information in the socket

		 * buffer otherwise it would be incorrectly forwarded

		 * to the frontend.

		 */

		skb_clear_hash(skb);



		return index;

	}



	xenvif_set_skb_hash(vif, skb);

drivers/net/xen-netback/netback.c

+66 −12
Original line number Diff line number Diff line
@@ -168,6 +168,8 @@ static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue) 
	needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE);

	if (skb_is_gso(skb))

		needed++;

	if (skb->sw_hash)

		needed++;



	do {

		prod = queue->rx.sring->req_prod;
@@ -285,6 +287,8 @@ struct gop_frag_copy { 
	struct xenvif_rx_meta *meta;

	int head;

	int gso_type;

	int protocol;

	int hash_present;



	struct page *page;

};
@@ -331,8 +335,15 @@ static void xenvif_setup_copy_gop(unsigned long gfn, 
	npo->copy_off += *len;

	info->meta->size += *len;



	if (!info->head)

		return;



	/* Leave a gap for the GSO descriptor. */

	if (info->head && ((1 << info->gso_type) & queue->vif->gso_mask))

	if ((1 << info->gso_type) & queue->vif->gso_mask)

		queue->rx.req_cons++;



	/* Leave a gap for the hash extra segment. */

	if (info->hash_present)

		queue->rx.req_cons++;



	info->head = 0; /* There must be something in this buffer now */
@@ -367,6 +378,11 @@ static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb 
		.npo = npo,

		.head = *head,

		.gso_type = XEN_NETIF_GSO_TYPE_NONE,

		/* xenvif_set_skb_hash() will have either set a s/w

		 * hash or cleared the hash depending on

		 * whether the the frontend wants a hash for this skb.

		 */

		.hash_present = skb->sw_hash,

	};

	unsigned long bytes;
@@ -555,6 +571,7 @@ void xenvif_kick_thread(struct xenvif_queue *queue) 


static void xenvif_rx_action(struct xenvif_queue *queue)

{

	struct xenvif *vif = queue->vif;

	s8 status;

	u16 flags;

	struct xen_netif_rx_response *resp;
@@ -590,9 +607,10 @@ static void xenvif_rx_action(struct xenvif_queue *queue) 
	gnttab_batch_copy(queue->grant_copy_op, npo.copy_prod);



	while ((skb = __skb_dequeue(&rxq)) != NULL) {

		struct xen_netif_extra_info *extra = NULL;



		if ((1 << queue->meta[npo.meta_cons].gso_type) &

		    queue->vif->gso_prefix_mask) {

		    vif->gso_prefix_mask) {

			resp = RING_GET_RESPONSE(&queue->rx,

						 queue->rx.rsp_prod_pvt++);
@@ -610,7 +628,7 @@ static void xenvif_rx_action(struct xenvif_queue *queue) 
		queue->stats.tx_bytes += skb->len;

		queue->stats.tx_packets++;



		status = xenvif_check_gop(queue->vif,

		status = xenvif_check_gop(vif,

					  XENVIF_RX_CB(skb)->meta_slots_used,

					  &npo);
@@ -632,21 +650,57 @@ static void xenvif_rx_action(struct xenvif_queue *queue) 
					flags);



		if ((1 << queue->meta[npo.meta_cons].gso_type) &

		    queue->vif->gso_mask) {

			struct xen_netif_extra_info *gso =

				(struct xen_netif_extra_info *)

		    vif->gso_mask) {

			extra = (struct xen_netif_extra_info *)

				RING_GET_RESPONSE(&queue->rx,

						  queue->rx.rsp_prod_pvt++);



			resp->flags |= XEN_NETRXF_extra_info;



			gso->u.gso.type = queue->meta[npo.meta_cons].gso_type;

			gso->u.gso.size = queue->meta[npo.meta_cons].gso_size;

			gso->u.gso.pad = 0;

			gso->u.gso.features = 0;

			extra->u.gso.type = queue->meta[npo.meta_cons].gso_type;

			extra->u.gso.size = queue->meta[npo.meta_cons].gso_size;

			extra->u.gso.pad = 0;

			extra->u.gso.features = 0;



			extra->type = XEN_NETIF_EXTRA_TYPE_GSO;

			extra->flags = 0;

		}



		if (skb->sw_hash) {

			/* Since the skb got here via xenvif_select_queue()

			 * we know that the hash has been re-calculated

			 * according to a configuration set by the frontend

			 * and therefore we know that it is legitimate to

			 * pass it to the frontend.

			 */

			if (resp->flags & XEN_NETRXF_extra_info)

				extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;

			else

				resp->flags |= XEN_NETRXF_extra_info;



			extra = (struct xen_netif_extra_info *)

				RING_GET_RESPONSE(&queue->rx,

						  queue->rx.rsp_prod_pvt++);



			extra->u.hash.algorithm =

				XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ;



			if (skb->l4_hash)

				extra->u.hash.type =

					skb->protocol == htons(ETH_P_IP) ?

					_XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP :

					_XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP;

			else

				extra->u.hash.type =

					skb->protocol == htons(ETH_P_IP) ?

					_XEN_NETIF_CTRL_HASH_TYPE_IPV4 :

					_XEN_NETIF_CTRL_HASH_TYPE_IPV6;



			*(uint32_t *)extra->u.hash.value =

				skb_get_hash_raw(skb);



			gso->type = XEN_NETIF_EXTRA_TYPE_GSO;

			gso->flags = 0;

			extra->type = XEN_NETIF_EXTRA_TYPE_HASH;

			extra->flags = 0;

		}



		xenvif_add_frag_responses(queue, status,