From 1c9535c701fb287c2f292bc7fb39a07c5f8a25fd Mon Sep 17 00:00:00 2001 From: Denis Kirjanov Date: Mon, 29 Jun 2020 16:13:29 +0300 Subject: 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: Paul Durrant Signed-off-by: Denis Kirjanov Signed-off-by: David S. Miller --- drivers/net/xen-netback/common.h | 4 ++++ drivers/net/xen-netback/interface.c | 2 ++ drivers/net/xen-netback/netback.c | 7 +++++++ drivers/net/xen-netback/rx.c | 15 ++++++++++++++- drivers/net/xen-netback/xenbus.c | 34 ++++++++++++++++++++++++++++++++++ 5 files changed, 61 insertions(+), 1 deletion(-) (limited to 'drivers/net/xen-netback') diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index 05847eb91a1b..ae477f7756af 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -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; diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index 0c8a02a1ead7..8af497285691 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -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); diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 315dfc6ea297..6dfca7265644 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -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); diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c index ef5887037b22..ac034f69a170 100644 --- a/drivers/net/xen-netback/rx.c +++ b/drivers/net/xen-netback/rx.c @@ -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 { diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 286054b60d47..7e62a6ee7622 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -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). */ -- cgit