/* * Virtual network driver for conversing with remote driver backends. * * Copyright (c) 2002-2005, K A Fraser * Copyright (c) 2005, XenSource Ltd * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation; or, when distributed * separately from the Linux kernel or incorporated into other * software packages, subject to the following license: * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this source file (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, copy, modify, * merge, publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Module parameters */ #define MAX_QUEUES_DEFAULT 8 static unsigned int xennet_max_queues; module_param_named(max_queues, xennet_max_queues, uint, 0644); MODULE_PARM_DESC(max_queues, "Maximum number of queues per virtual interface"); static const struct ethtool_ops xennet_ethtool_ops; struct netfront_cb { int pull_to; }; #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) #define RX_COPY_THRESHOLD 256 #define GRANT_INVALID_REF 0 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE) #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE) /* Minimum number of Rx slots (includes slot for GSO metadata). */ #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1) /* Queue name is interface name with "-qNNN" appended */ #define QUEUE_NAME_SIZE (IFNAMSIZ + 6) /* IRQ name is queue name with "-tx" or "-rx" appended */ #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3) static DECLARE_WAIT_QUEUE_HEAD(module_wq); struct netfront_stats { u64 packets; u64 bytes; struct u64_stats_sync syncp; }; struct netfront_info; struct netfront_queue { unsigned int id; /* Queue ID, 0-based */ char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */ struct netfront_info *info; struct napi_struct napi; /* Split event channels support, tx_* == rx_* when using * single event channel. */ unsigned int tx_evtchn, rx_evtchn; unsigned int tx_irq, rx_irq; /* Only used when split event channels support is enabled */ char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */ char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */ spinlock_t tx_lock; struct xen_netif_tx_front_ring tx; int tx_ring_ref; /* * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries * are linked from tx_skb_freelist through skb_entry.link. * * NB. Freelist index entries are always going to be less than * PAGE_OFFSET, whereas pointers to skbs will always be equal or * greater than PAGE_OFFSET: we use this property to distinguish * them. */ union skb_entry { struct sk_buff *skb; unsigned long link; } tx_skbs[NET_TX_RING_SIZE]; grant_ref_t gref_tx_head; grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; struct page *grant_tx_page[NET_TX_RING_SIZE]; unsigned tx_skb_freelist; spinlock_t rx_lock ____cacheline_aligned_in_smp; struct xen_netif_rx_front_ring rx; int rx_ring_ref; struct timer_list rx_refill_timer; struct sk_buff *rx_skbs[NET_RX_RING_SIZE]; grant_ref_t gref_rx_head; grant_ref_t grant_rx_ref[NET_RX_RING_SIZE]; }; struct netfront_info { struct list_head list; struct net_device *netdev; struct xenbus_device *xbdev; /* Multi-queue support */ struct netfront_queue *queues; /* Statistics */ struct netfront_stats __percpu *rx_stats; struct netfront_stats __percpu *tx_stats; atomic_t rx_gso_checksum_fixup; }; struct netfront_rx_info { struct xen_netif_rx_response rx; struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; }; static void skb_entry_set_link(union skb_entry *list, unsigned short id) { list->link = id; } static int skb_entry_is_link(const union skb_entry *list) { BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link)); return (unsigned long)list->skb < PAGE_OFFSET; } /* * Access macros for acquiring freeing slots in tx_skbs[]. */ static void add_id_to_freelist(unsigned *head, union skb_entry *list, unsigned short id) { skb_entry_set_link(&list[id], *head); *head = id; } static unsigned short get_id_from_freelist(unsigned *head, union skb_entry *list) { unsigned int id = *head; *head = list[id].link; return id; } static int xennet_rxidx(RING_IDX idx) { return idx & (NET_RX_RING_SIZE - 1); } static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue, RING_IDX ri) { int i = xennet_rxidx(ri); struct sk_buff *skb = queue->rx_skbs[i]; queue->rx_skbs[i] = NULL; return skb; } static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue, RING_IDX ri) { int i = xennet_rxidx(ri); grant_ref_t ref = queue->grant_rx_ref[i]; queue->grant_rx_ref[i] = GRANT_INVALID_REF; return ref; } #ifdef CONFIG_SYSFS static const struct attribute_group xennet_dev_group; #endif static bool xennet_can_sg(struct net_device *dev) { return dev->features & NETIF_F_SG; } static void rx_refill_timeout(struct timer_list *t) { struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer); napi_schedule(&queue->napi); } static int netfront_tx_slot_available(struct netfront_queue *queue) { return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) < (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1); } static void xennet_maybe_wake_tx(struct netfront_queue *queue) { struct net_device *dev = queue->info->netdev; struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id); if (unlikely(netif_tx_queue_stopped(dev_queue)) && netfront_tx_slot_available(queue) && likely(netif_running(dev))) netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id)); } static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue) { struct sk_buff *skb; struct page *page; skb = __netdev_alloc_skb(queue->info->netdev, RX_COPY_THRESHOLD + NET_IP_ALIGN, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!skb)) return NULL; page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); if (!page) { kfree_skb(skb); return NULL; } skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE); /* Align ip header to a 16 bytes boundary */ skb_reserve(skb, NET_IP_ALIGN); skb->dev = queue->info->netdev; return skb; } static void xennet_alloc_rx_buffers(struct netfront_queue *queue) { RING_IDX req_prod = queue->rx.req_prod_pvt; int notify; int err = 0; if (unlikely(!netif_carrier_ok(queue->info->netdev))) return; for (req_prod = queue->rx.req_prod_pvt; req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE; req_prod++) { struct sk_buff *skb; unsigned short id; grant_ref_t ref; struct page *page; struct xen_netif_rx_request *req; skb = xennet_alloc_one_rx_buffer(queue); if (!skb) { err = -ENOMEM; break; } id = xennet_rxidx(req_prod); BUG_ON(queue->rx_skbs[id]); queue->rx_skbs[id] = skb; ref = gnttab_claim_grant_reference(&queue->gref_rx_head); WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); queue->grant_rx_ref[id] = ref; page = skb_frag_page(&skb_shinfo(skb)->frags[0]); req = RING_GET_REQUEST(&queue->rx, req_prod); gnttab_page_grant_foreign_access_ref_one(ref, queue->info->xbdev->otherend_id, page, 0); req->id = id; req->gref = ref; } queue->rx.req_prod_pvt = req_prod; /* Try again later if there are not enough requests or skb allocation * failed. * Enough requests is quantified as the sum of newly created slots and * the unconsumed slots at the backend. */ if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN || unlikely(err)) { mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10)); return; } RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify); if (notify) notify_remote_via_irq(queue->rx_irq); } static int xennet_open(struct net_device *dev) { struct netfront_info *np = netdev_priv(dev); unsigned int num_queues = dev->real_num_tx_queues; unsigned int i = 0; struct netfront_queue *queue = NULL; if (!np->queues) return -ENODEV; for (i = 0; i < num_queues; ++i) { queue = &np->queues[i]; napi_enable(&queue->napi); spin_lock_bh(&queue->rx_lock); if (netif_carrier_ok(dev)) { xennet_alloc_rx_buffers(queue); queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1; if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)) napi_schedule(&queue->napi); } spin_unlock_bh(&queue->rx_lock); } netif_tx_start_all_queues(dev); return 0; } static void xennet_tx_buf_gc(struct netfront_queue *queue) { RING_IDX cons, prod; unsigned short id; struct sk_buff *skb; bool more_to_do; BUG_ON(!netif_carrier_ok(queue->info->netdev)); do { prod = queue->tx.sring->rsp_prod; rmb(); /* Ensure we see responses up to 'rp'. */ for (cons = queue->tx.rsp_cons; cons != prod; cons++) { struct xen_netif_tx_response *txrsp; txrsp = RING_GET_RESPONSE(&queue->tx, cons); if (txrsp->status == XEN_NETIF_RSP_NULL) continue; id = txrsp->id; skb = queue->tx_skbs[id].skb; if (unlikely(gnttab_query_foreign_access( queue->grant_tx_ref[id]) != 0)) { pr_alert("%s: warning -- grant still in use by backend domain\n", __func__); BUG(); } gnttab_end_foreign_access_ref( queue->grant_tx_ref[id], GNTMAP_readonly); gnttab_release_grant_reference( &queue->gref_tx_head, queue->grant_tx_ref[id]); queue->grant_tx_ref[id] = GRANT_INVALID_REF; queue->grant_tx_page[id] = NULL; add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id); dev_kfree_skb_irq(skb); } queue->tx.rsp_cons = prod; RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do); } while (more_to_do); xennet_maybe_wake_tx(queue); } struct xennet_gnttab_make_txreq { struct netfront_queue *queue; struct sk_buff *skb; struct page *page; struct xen_netif_tx_request *tx; /* Last request */ unsigned int size; }; static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset, unsigned int len, void *data) { struct xennet_gnttab_make_txreq *info = data; unsigned int id; struct xen_netif_tx_request *tx; grant_ref_t ref; /* convenient aliases */ struct page *page = info->page; struct netfront_queue *queue = info->queue; struct sk_buff *skb = info->skb; id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs); tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); ref = gnttab_claim_grant_reference(&queue->gref_tx_head); WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref)); gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id, gfn, GNTMAP_readonly); queue->tx_skbs[id].skb = skb; queue->grant_tx_page[id] = page; queue->grant_tx_ref[id] = ref; tx->id = id; tx->gref = ref; tx->offset = offset; tx->size = len; tx->flags = 0; info->tx = tx; info->size += tx->size; } static struct xen_netif_tx_request *xennet_make_first_txreq( struct netfront_queue *queue, struct sk_buff *skb, struct page *page, unsigned int offset, unsigned int len) { struct xennet_gnttab_make_txreq info = { .queue = queue, .skb = skb, .page = page, .size = 0, }; gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info); return info.tx; } static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset, unsigned int len, void *data) { struct xennet_gnttab_make_txreq *info = data; info->tx->flags |= XEN_NETTXF_more_data; skb_get(info->skb); xennet_tx_setup_grant(gfn, offset, len, data); } static struct xen_netif_tx_request *xennet_make_txreqs( struct netfront_queue *queue, struct xen_netif_tx_request *tx, struct sk_buff *skb, struct page *page, unsigned int offset, unsigned int len) { struct xennet_gnttab_make_txreq info = { .queue = queue, .skb = skb, .tx = tx, }; /* Skip unused frames from start of page */ page += offset >> PAGE_SHIFT; offset &= ~PAGE_MASK; while (len) { info.page = page; info.size = 0; gnttab_foreach_grant_in_range(page, offset, len, xennet_make_one_txreq, &info); page++; offset = 0; len -= info.size; } return info.tx; } /* * Count how many ring slots are required to send this skb. Each frag * might be a compound page. */ static int xennet_count_skb_slots(struct sk_buff *skb) { int i, frags = skb_shinfo(skb)->nr_frags; int slots; slots = gnttab_count_grant(offset_in_page(skb->data), skb_headlen(skb)); for (i = 0; i < frags; i++) { skb_frag_t *frag = skb_shinfo(skb)->frags + i; unsigned long size = skb_frag_size(frag); unsigned long offset = frag->page_offset; /* Skip unused frames from start of page */ offset &= ~PAGE_MASK; slots += gnttab_count_grant(offset, size); } return slots; } static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb, struct net_device *sb_dev, select_queue_fallback_t fallback) { unsigned int num_queues = dev->real_num_tx_queues; u32 hash; u16 queue_idx; /* First, check if there is only one queue */ if (num_queues == 1) { queue_idx = 0; } else { hash = skb_get_hash(skb); queue_idx = hash % num_queues; } return queue_idx; } #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1) static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct netfront_info *np = netdev_priv(dev); struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats); struct xen_netif_tx_request *tx, *first_tx; unsigned int i; int notify; int slots; struct page *page; unsigned int offset; unsigned int len; unsigned long flags; struct netfront_queue *queue = NULL; unsigned int num_queues = dev->real_num_tx_queues; u16 queue_index; struct sk_buff *nskb; /* Drop the packet if no queues are set up */ if (num_queues < 1) goto drop; /* Determine which queue to transmit this SKB on */ queue_index = skb_get_queue_mapping(skb); queue = &np->queues[queue_index]; /* If skb->len is too big for wire format, drop skb and alert * user about misconfiguration. */ if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { net_alert_ratelimited( "xennet: skb->len = %u, too big for wire format\n", skb->len); goto drop; } slots = xennet_count_skb_slots(skb); if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) { net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n", slots, skb->len); if (skb_linearize(skb)) goto drop; } page = virt_to_page(skb->data); offset = offset_in_page(skb->data); /* The first req should be at least ETH_HLEN size or the packet will be * dropped by netback. */ if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) { nskb = skb_copy(skb, GFP_ATOMIC); if (!nskb) goto drop; dev_consume_skb_any(skb); skb = nskb; page = virt_to_page(skb->data); offset = offset_in_page(skb->data); } len = skb_headlen(skb); spin_lock_irqsave(&queue->tx_lock, flags); if (unlikely(!netif_carrier_ok(dev) || (slots > 1 && !xennet_can_sg(dev)) || netif_needs_gso(skb, netif_skb_features(skb)))) { spin_unlock_irqrestore(&queue->tx_lock, flags); goto drop; } /* First request for the linear area. */ first_tx = tx = xennet_make_first_txreq(queue, skb, page, offset, len); offset += tx->size; if (offset == PAGE_SIZE) { page++; offset = 0; } len -= tx->size; if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */ tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated; else if (skb->ip_summed == CHECKSUM_UNNECESSARY) /* remote but checksummed. */ tx->flags |= XEN_NETTXF_data_validated; /* Optional extra info after the first request. */ if (skb_shinfo(skb)->gso_size) { struct xen_netif_extra_info *gso; gso = (struct xen_netif_extra_info *) RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++); tx->flags |= XEN_NETTXF_extra_info; gso->u.gso.size = skb_shinfo(skb)->gso_size; gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ? XEN_NETIF_GSO_TYPE_TCPV6 : XEN_NETIF_GSO_TYPE_TCPV4; gso->u.gso.pad = 0; gso->u.gso.features = 0; gso->type = XEN_NETIF_EXTRA_TYPE_GSO; gso->flags = 0; } /* Requests for the rest of the linear area. */ tx = xennet_make_txreqs(queue, tx, skb, page, offset, len); /* Requests for all the frags. */ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; tx = xennet_make_txreqs(queue, tx, skb, skb_frag_page(frag), frag->page_offset, skb_frag_size(frag)); } /* First request has the packet length. */ first_tx->size = skb->len; RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify); if (notify) notify_remote_via_irq(queue->tx_irq); u64_stats_update_begin(&tx_stats->syncp); tx_stats->bytes += skb->len; tx_stats->packets++; u64_stats_update_end(&tx_stats->syncp); /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ xennet_tx_buf_gc(queue); if (!netfront_tx_slot_available(queue)) netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id)); spin_unlock_irqrestore(&queue->tx_lock, flags); return NETDEV_TX_OK; drop: dev->stats.tx_dropped++; dev_kfree_skb_any(skb); return NETDEV_TX_OK; } static int xennet_close(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; netif_tx_stop_all_queues(np->netdev); for (i = 0; i < num_queues; ++i) { queue = &np->queues[i]; napi_disable(&queue->napi); } return 0; } static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb, grant_ref_t ref) { int new = xennet_rxidx(queue->rx.req_prod_pvt); BUG_ON(queue->rx_skbs[new]); queue->rx_skbs[new] = skb; queue->grant_rx_ref[new] = ref; RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new; RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref; queue->rx.req_prod_pvt++; } static int xennet_get_extras(struct netfront_queue *queue, struct xen_netif_extra_info *extras, RING_IDX rp) { struct xen_netif_extra_info *extra; struct device *dev = &queue->info->netdev->dev; RING_IDX cons = queue->rx.rsp_cons; int err = 0; do { struct sk_buff *skb; grant_ref_t ref; if (unlikely(cons + 1 == rp)) { if (net_ratelimit()) dev_warn(dev, "Missing extra info\n"); err = -EBADR; break; } extra = (struct xen_netif_extra_info *) RING_GET_RESPONSE(&queue->rx, ++cons); if (unlikely(!extra->type || extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { if (net_ratelimit()) dev_warn(dev, "Invalid extra type: %d\n", extra->type); err = -EINVAL; } else { memcpy(&extras[extra->type - 1], extra, sizeof(*extra)); } skb = xennet_get_rx_skb(queue, cons); ref = xennet_get_rx_ref(queue, cons); xennet_move_rx_slot(queue, skb, ref); } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); queue->rx.rsp_cons = cons; return err; } static int xennet_get_responses(struct netfront_queue *queue, struct netfront_rx_info *rinfo, RING_IDX rp, struct sk_buff_head *list) { struct xen_netif_rx_response *rx = &rinfo->rx; struct xen_netif_extra_info *extras = rinfo->extras; struct device *dev = &queue->info->netdev->dev; RING_IDX cons = queue->rx.rsp_cons; struct sk_buff *skb = xennet_get_rx_skb(queue, cons); grant_ref_t ref = xennet_get_rx_ref(queue, cons); int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD); int slots = 1; int err = 0; unsigned long ret; if (rx->flags & XEN_NETRXF_extra_info) { err = xennet_get_extras(queue, extras, rp); cons = queue->rx.rsp_cons; } for (;;) { if (unlikely(rx->status < 0 || rx->offset + rx->status > XEN_PAGE_SIZE)) { if (net_ratelimit()) dev_warn(dev, "rx->offset: %u, size: %d\n", rx->offset, rx->status); xennet_move_rx_slot(queue, skb, ref); err = -EINVAL; goto next; } /* * This definitely indicates a bug, either in this driver or in * the backend driver. In future this should flag the bad * situation to the system controller to reboot the backend. */ if (ref == GRANT_INVALID_REF) { if (net_ratelimit()) dev_warn(dev, "Bad rx response id %d.\n", rx->id); err = -EINVAL; goto next; } ret = gnttab_end_foreign_access_ref(ref, 0); BUG_ON(!ret); gnttab_release_grant_reference(&queue->gref_rx_head, ref); __skb_queue_tail(list, skb); next: if (!(rx->flags & XEN_NETRXF_more_data)) break; if (cons + slots == rp) { if (net_ratelimit()) dev_warn(dev, "Need more slots\n"); err = -ENOENT; break; } rx = RING_GET_RESPONSE(&queue->rx, cons + slots); skb = xennet_get_rx_skb(queue, cons + slots); ref = xennet_get_rx_ref(queue, cons + slots); slots++; } if (unlikely(slots > max)) { if (net_ratelimit()) dev_warn(dev, "Too many slots\n"); err = -E2BIG; } if (unlikely(err)) queue->rx.rsp_cons = cons + slots; return err; } static int xennet_set_skb_gso(struct sk_buff *skb, struct xen_netif_extra_info *gso) { if (!gso->u.gso.size) { if (net_ratelimit()) pr_warn("GSO size must not be zero\n"); return -EINVAL; } if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 && gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) { if (net_ratelimit()) pr_warn("Bad GSO type %d\n", gso->u.gso.type); return -EINVAL; } skb_shinfo(skb)->gso_size = gso->u.gso.size; skb_shinfo(skb)->gso_type = (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ? SKB_GSO_TCPV4 : SKB_GSO_TCPV6; /* Header must be checked, and gso_segs computed. */ skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; skb_shinfo(skb)->gso_segs = 0; return 0; } static RING_IDX xennet_fill_frags(struct netfront_queue *queue, struct sk_buff *skb, struct sk_buff_head *list) { RING_IDX cons = queue->rx.rsp_cons; struct sk_buff *nskb; while ((nskb = __skb_dequeue(list))) { struct xen_netif_rx_response *rx = RING_GET_RESPONSE(&queue->rx, ++cons); skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) { unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; BUG_ON(pull_to < skb_headlen(skb)); __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); } if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) { queue->rx.rsp_cons = ++cons; kfree_skb(nskb); return ~0U; } skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, skb_frag_page(nfrag), rx->offset, rx->status, PAGE_SIZE); skb_shinfo(nskb)->nr_frags = 0; kfree_skb(nskb); } return cons; } static int checksum_setup(struct net_device *dev, struct sk_buff *skb) { bool recalculate_partial_csum = false; /* * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy * peers can fail to set NETRXF_csum_blank when sending a GSO * frame. In this case force the SKB to CHECKSUM_PARTIAL and * recalculate the partial checksum. */ if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { struct netfront_info *np = netdev_priv(dev); atomic_inc(&np->rx_gso_checksum_fixup); skb->ip_summed = CHECKSUM_PARTIAL; recalculate_partial_csum = true; } /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ if (skb->ip_summed != CHECKSUM_PARTIAL) return 0; return skb_checksum_setup(skb, recalculate_partial_csum); } static int handle_incoming_queue(struct netfront_queue *queue, struct sk_buff_head *rxq) { struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats); int packets_dropped = 0; struct sk_buff *skb; while ((skb = __skb_dequeue(rxq)) != NULL) { int pull_to = NETFRONT_SKB_CB(skb)->pull_to; if (pull_to > skb_headlen(skb)) __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); /* Ethernet work: Delayed to here as it peeks the header. */ skb->protocol = eth_type_trans(skb, queue->info->netdev); skb_reset_network_header(skb); if (checksum_setup(queue->info->netdev, skb)) { kfree_skb(skb); packets_dropped++; queue->info->netdev->stats.rx_errors++; continue; } u64_stats_update_begin(&rx_stats->syncp); rx_stats->packets++; rx_stats->bytes += skb->len; u64_stats_update_end(&rx_stats->syncp); /* Pass it up. */ napi_gro_receive(&queue->napi, skb); } return packets_dropped; } static int xennet_poll(struct napi_struct *napi, int budget) { struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi); struct net_device *dev = queue->info->netdev; struct sk_buff *skb; struct netfront_rx_info rinfo; struct xen_netif_rx_response *rx = &rinfo.rx; struct xen_netif_extra_info *extras = rinfo.extras; RING_IDX i, rp; int work_done; struct sk_buff_head rxq; struct sk_buff_head errq; struct sk_buff_head tmpq; int err; spin_lock(&queue->rx_lock); skb_queue_head_init(&rxq); skb_queue_head_init(&errq); skb_queue_head_init(&tmpq); rp = queue->rx.sring->rsp_prod; rmb(); /* Ensure we see queued responses up to 'rp'. */ i = queue->rx.rsp_cons; work_done = 0; while ((i != rp) && (work_done < budget)) { memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx)); memset(extras, 0, sizeof(rinfo.extras)); err = xennet_get_responses(queue, &rinfo, rp, &tmpq); if (unlikely(err)) { err: while ((skb = __skb_dequeue(&tmpq))) __skb_queue_tail(&errq, skb); dev->stats.rx_errors++; i = queue->rx.rsp_cons; continue; } skb = __skb_dequeue(&tmpq); if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { struct xen_netif_extra_info *gso; gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; if (unlikely(xennet_set_skb_gso(skb, gso))) { __skb_queue_head(&tmpq, skb); queue->rx.rsp_cons += skb_queue_len(&tmpq); goto err; } } NETFRONT_SKB_CB(skb)->pull_to = rx->status; if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; skb_shinfo(skb)->frags[0].page_offset = rx->offset; skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); skb->data_len = rx->status; skb->len += rx->status; i = xennet_fill_frags(queue, skb, &tmpq); if (unlikely(i == ~0U)) goto err; if (rx->flags & XEN_NETRXF_csum_blank) skb->ip_summed = CHECKSUM_PARTIAL; else if (rx->flags & XEN_NETRXF_data_validated) skb->ip_summed = CHECKSUM_UNNECESSARY; __skb_queue_tail(&rxq, skb); queue->rx.rsp_cons = ++i; work_done++; } __skb_queue_purge(&errq); work_done -= handle_incoming_queue(queue, &rxq); xennet_alloc_rx_buffers(queue); if (work_done < budget) { int more_to_do = 0; napi_complete_done(napi, work_done); RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do); if (more_to_do) napi_schedule(napi); } spin_unlock(&queue->rx_lock); return work_done; } static int xennet_change_mtu(struct net_device *dev, int mtu) { int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN; if (mtu > max) return -EINVAL; dev->mtu = mtu; return 0; } static void xennet_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *tot) { struct netfront_info *np = netdev_priv(dev); int cpu; for_each_possible_cpu(cpu) { struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu); struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu); u64 rx_packets, rx_bytes, tx_packets, tx_bytes; unsigned int start; do { start = u64_stats_fetch_begin_irq(&tx_stats->syncp); tx_packets = tx_stats->packets; tx_bytes = tx_stats->bytes; } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start)); do { start = u64_stats_fetch_begin_irq(&rx_stats->syncp); rx_packets = rx_stats->packets; rx_bytes = rx_stats->bytes; } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start)); tot->rx_packets += rx_packets; tot->tx_packets += tx_packets; tot->rx_bytes += rx_bytes; tot->tx_bytes += tx_bytes; } tot->rx_errors = dev->stats.rx_errors; tot->tx_dropped = dev->stats.tx_dropped; } static void xennet_release_tx_bufs(struct netfront_queue *queue) { struct sk_buff *skb; int i; for (i = 0; i < NET_TX_RING_SIZE; i++) { /* Skip over entries which are actually freelist references */ if (skb_entry_is_link(&queue->tx_skbs[i])) continue; skb = queue->tx_skbs[i].skb; get_page(queue->grant_tx_page[i]); gnttab_end_foreign_access(queue->grant_tx_ref[i], GNTMAP_readonly, (unsigned long)page_address(queue->grant_tx_page[i])); queue->grant_tx_page[i] = NULL; queue->grant_tx_ref[i] = GRANT_INVALID_REF; add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i); dev_kfree_skb_irq(skb); } } static void xennet_release_rx_bufs(struct netfront_queue *queue) { int id, ref; spin_lock_bh(&queue->rx_lock); for (id = 0; id < NET_RX_RING_SIZE; id++) { struct sk_buff *skb; struct page *page; skb = queue->rx_skbs[id]; if (!skb) continue; ref = queue->grant_rx_ref[id]; if (ref == GRANT_INVALID_REF) continue; page = skb_frag_page(&skb_shinfo(skb)->frags[0]); /* gnttab_end_foreign_access() needs a page ref until * foreign access is ended (which may be deferred). */ get_page(page); gnttab_end_foreign_access(ref, 0, (unsigned long)page_address(page)); queue->grant_rx_ref[id] = GRANT_INVALID_REF; kfree_skb(skb); } spin_unlock_bh(&queue->rx_lock); } static netdev_features_t xennet_fix_features(struct net_device *dev, netdev_features_t features) { struct netfront_info *np = netdev_priv(dev); if (features & NETIF_F_SG && !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0)) features &= ~NETIF_F_SG; if (features & NETIF_F_IPV6_CSUM && !xenbus_read_unsigned(np->xbdev->otherend, "feature-ipv6-csum-offload", 0)) features &= ~NETIF_F_IPV6_CSUM; if (features & NETIF_F_TSO && !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0)) features &= ~NETIF_F_TSO; if (features & NETIF_F_TSO6 && !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0)) features &= ~NETIF_F_TSO6; return features; } static int xennet_set_features(struct net_device *dev, netdev_features_t features) { if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { netdev_info(dev, "Reducing MTU because no SG offload"); dev->mtu = ETH_DATA_LEN; } return 0; } static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) { struct netfront_queue *queue = dev_id; unsigned long flags; spin_lock_irqsave(&queue->tx_lock, flags); xennet_tx_buf_gc(queue); spin_unlock_irqrestore(&queue->tx_lock, flags); return IRQ_HANDLED; } static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) { struct netfront_queue *queue = dev_id; struct net_device *dev = queue->info->netdev; if (likely(netif_carrier_ok(dev) && RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))) napi_schedule(&queue->napi); return IRQ_HANDLED; } static irqreturn_t xennet_interrupt(int irq, void *dev_id) { xennet_tx_interrupt(irq, dev_id); xennet_rx_interrupt(irq, dev_id); return IRQ_HANDLED; } #ifdef CONFIG_NET_POLL_CONTROLLER static void xennet_poll_controller(struct net_device *dev) { /* Poll each queue */ struct netfront_info *info = netdev_priv(dev); unsigned int num_queues = dev->real_num_tx_queues; unsigned int i; for (i = 0; i < num_queues; ++i) xennet_interrupt(0, &info->queues[i]); } #endif static const struct net_device_ops xennet_netdev_ops = { .ndo_open = xennet_open, .ndo_stop = xennet_close, .ndo_start_xmit = xennet_start_xmit, .ndo_change_mtu = xennet_change_mtu, .ndo_get_stats64 = xennet_get_stats64, .ndo_set_mac_address = eth_mac_addr, .ndo_validate_addr = eth_validate_addr, .ndo_fix_features = xennet_fix_features, .ndo_set_features = xennet_set_features, .ndo_select_queue = xennet_select_queue, #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = xennet_poll_controller, #endif }; static void xennet_free_netdev(struct net_device *netdev) { struct netfront_info *np = netdev_priv(netdev); free_percpu(np->rx_stats); free_percpu(np->tx_stats); free_netdev(netdev); } static struct net_device *xennet_create_dev(struct xenbus_device *dev) { int err; struct net_device *netdev; struct netfront_info *np; netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues); if (!netdev) return ERR_PTR(-ENOMEM); np = netdev_priv(netdev); np->xbdev = dev; np->queues = NULL; err = -ENOMEM; np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); if (np->rx_stats == NULL) goto exit; np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); if (np->tx_stats == NULL) goto exit; netdev->netdev_ops = &xennet_netdev_ops; netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | NETIF_F_GSO_ROBUST; netdev->hw_features = NETIF_F_SG | NETIF_F_IPV6_CSUM | NETIF_F_TSO | NETIF_F_TSO6; /* * Assume that all hw features are available for now. This set * will be adjusted by the call to netdev_update_features() in * xennet_connect() which is the earliest point where we can * negotiate with the backend regarding supported features. */ netdev->features |= netdev->hw_features; netdev->ethtool_ops = &xennet_ethtool_ops; netdev->min_mtu = ETH_MIN_MTU; netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE; SET_NETDEV_DEV(netdev, &dev->dev); np->netdev = netdev; netif_carrier_off(netdev); xenbus_switch_state(dev, XenbusStateInitialising); wait_event(module_wq, xenbus_read_driver_state(dev->otherend) != XenbusStateClosed && xenbus_read_driver_state(dev->otherend) != XenbusStateUnknown); return netdev; exit: xennet_free_netdev(netdev); return ERR_PTR(err); } /** * Entry point to this code when a new device is created. Allocate the basic * structures and the ring buffers for communication with the backend, and * inform the backend of the appropriate details for those. */ static int netfront_probe(struct xenbus_device *dev, const struct xenbus_device_id *id) { int err; struct net_device *netdev; struct netfront_info *info; netdev = xennet_create_dev(dev); if (IS_ERR(netdev)) { err = PTR_ERR(netdev); xenbus_dev_fatal(dev, err, "creating netdev"); return err; } info = netdev_priv(netdev); dev_set_drvdata(&dev->dev, info); #ifdef CONFIG_SYSFS info->netdev->sysfs_groups[0] = &xennet_dev_group; #endif return 0; } static void xennet_end_access(int ref, void *page) { /* This frees the page as a side-effect */ if (ref != GRANT_INVALID_REF) gnttab_end_foreign_access(ref, 0, (unsigned long)page); } static void xennet_disconnect_backend(struct netfront_info *info) { unsigned int i = 0; unsigned int num_queues = info->netdev->real_num_tx_queues; netif_carrier_off(info->netdev); for (i = 0; i < num_queues && info->queues; ++i) { struct netfront_queue *queue = &info->queues[i]; del_timer_sync(&queue->rx_refill_timer); if (queue->tx_irq && (queue->tx_irq == queue->rx_irq)) unbind_from_irqhandler(queue->tx_irq, queue); if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) { unbind_from_irqhandler(queue->tx_irq, queue); unbind_from_irqhandler(queue->rx_irq, queue); } queue->tx_evtchn = queue->rx_evtchn = 0; queue->tx_irq = queue->rx_irq = 0; if (netif_running(info->netdev)) napi_synchronize(&queue->napi); xennet_release_tx_bufs(queue); xennet_release_rx_bufs(queue); gnttab_free_grant_references(queue->gref_tx_head); gnttab_free_grant_references(queue->gref_rx_head); /* End access and free the pages */ xennet_end_access(queue->tx_ring_ref, queue->tx.sring); xennet_end_access(queue->rx_ring_ref, queue->rx.sring); queue->tx_ring_ref = GRANT_INVALID_REF; queue->rx_ring_ref = GRANT_INVALID_REF; queue->tx.sring = NULL; queue->rx.sring = NULL; } } /** * We are reconnecting to the backend, due to a suspend/resume, or a backend * driver restart. We tear down our netif structure and recreate it, but * leave the device-layer structures intact so that this is transparent to the * rest of the kernel. */ static int netfront_resume(struct xenbus_device *dev) { struct netfront_info *info = dev_get_drvdata(&dev->dev); dev_dbg(&dev->dev, "%s\n", dev->nodename); xennet_disconnect_backend(info); return 0; } static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) { char *s, *e, *macstr; int i; macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); if (IS_ERR(macstr)) return PTR_ERR(macstr); for (i = 0; i < ETH_ALEN; i++) { mac[i] = simple_strtoul(s, &e, 16); if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { kfree(macstr); return -ENOENT; } s = e+1; } kfree(macstr); return 0; } static int setup_netfront_single(struct netfront_queue *queue) { int err; err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); if (err < 0) goto fail; err = bind_evtchn_to_irqhandler(queue->tx_evtchn, xennet_interrupt, 0, queue->info->netdev->name, queue); if (err < 0) goto bind_fail; queue->rx_evtchn = queue->tx_evtchn; queue->rx_irq = queue->tx_irq = err; return 0; bind_fail: xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); queue->tx_evtchn = 0; fail: return err; } static int setup_netfront_split(struct netfront_queue *queue) { int err; err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn); if (err < 0) goto fail; err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn); if (err < 0) goto alloc_rx_evtchn_fail; snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), "%s-tx", queue->name); err = bind_evtchn_to_irqhandler(queue->tx_evtchn, xennet_tx_interrupt, 0, queue->tx_irq_name, queue); if (err < 0) goto bind_tx_fail; queue->tx_irq = err; snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), "%s-rx", queue->name); err = bind_evtchn_to_irqhandler(queue->rx_evtchn, xennet_rx_interrupt, 0, queue->rx_irq_name, queue); if (err < 0) goto bind_rx_fail; queue->rx_irq = err; return 0; bind_rx_fail: unbind_from_irqhandler(queue->tx_irq, queue); queue->tx_irq = 0; bind_tx_fail: xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn); queue->rx_evtchn = 0; alloc_rx_evtchn_fail: xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn); queue->tx_evtchn = 0; fail: return err; } static int setup_netfront(struct xenbus_device *dev, struct netfront_queue *queue, unsigned int feature_split_evtchn) { struct xen_netif_tx_sring *txs; struct xen_netif_rx_sring *rxs; grant_ref_t gref; int err; queue->tx_ring_ref = GRANT_INVALID_REF; queue->rx_ring_ref = GRANT_INVALID_REF; queue->rx.sring = NULL; queue->tx.sring = NULL; txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); if (!txs) { err = -ENOMEM; xenbus_dev_fatal(dev, err, "allocating tx ring page"); goto fail; } SHARED_RING_INIT(txs); FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE); err = xenbus_grant_ring(dev, txs, 1, &gref); if (err < 0) goto grant_tx_ring_fail; queue->tx_ring_ref = gref; rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); if (!rxs) { err = -ENOMEM; xenbus_dev_fatal(dev, err, "allocating rx ring page"); goto alloc_rx_ring_fail; } SHARED_RING_INIT(rxs); FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE); err = xenbus_grant_ring(dev, rxs, 1, &gref); if (err < 0) goto grant_rx_ring_fail; queue->rx_ring_ref = gref; if (feature_split_evtchn) err = setup_netfront_split(queue); /* setup single event channel if * a) feature-split-event-channels == 0 * b) feature-split-event-channels == 1 but failed to setup */ if (!feature_split_evtchn || (feature_split_evtchn && err)) err = setup_netfront_single(queue); if (err) goto alloc_evtchn_fail; return 0; /* If we fail to setup netfront, it is safe to just revoke access to * granted pages because backend is not accessing it at this point. */ alloc_evtchn_fail: gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0); grant_rx_ring_fail: free_page((unsigned long)rxs); alloc_rx_ring_fail: gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0); grant_tx_ring_fail: free_page((unsigned long)txs); fail: return err; } /* Queue-specific initialisation * This used to be done in xennet_create_dev() but must now * be run per-queue. */ static int xennet_init_queue(struct netfront_queue *queue) { unsigned short i; int err = 0; char *devid; spin_lock_init(&queue->tx_lock); spin_lock_init(&queue->rx_lock); timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0); devid = strrchr(queue->info->xbdev->nodename, '/') + 1; snprintf(queue->name, sizeof(queue->name), "vif%s-q%u", devid, queue->id); /* Initialise tx_skbs as a free chain containing every entry. */ queue->tx_skb_freelist = 0; for (i = 0; i < NET_TX_RING_SIZE; i++) { skb_entry_set_link(&queue->tx_skbs[i], i+1); queue->grant_tx_ref[i] = GRANT_INVALID_REF; queue->grant_tx_page[i] = NULL; } /* Clear out rx_skbs */ for (i = 0; i < NET_RX_RING_SIZE; i++) { queue->rx_skbs[i] = NULL; queue->grant_rx_ref[i] = GRANT_INVALID_REF; } /* A grant for every tx ring slot */ if (gnttab_alloc_grant_references(NET_TX_RING_SIZE, &queue->gref_tx_head) < 0) { pr_alert("can't alloc tx grant refs\n"); err = -ENOMEM; goto exit; } /* A grant for every rx ring slot */ if (gnttab_alloc_grant_references(NET_RX_RING_SIZE, &queue->gref_rx_head) < 0) { pr_alert("can't alloc rx grant refs\n"); err = -ENOMEM; goto exit_free_tx; } return 0; exit_free_tx: gnttab_free_grant_references(queue->gref_tx_head); exit: return err; } static int write_queue_xenstore_keys(struct netfront_queue *queue, struct xenbus_transaction *xbt, int write_hierarchical) { /* Write the queue-specific keys into XenStore in the traditional * way for a single queue, or in a queue subkeys for multiple * queues. */ struct xenbus_device *dev = queue->info->xbdev; int err; const char *message; char *path; size_t pathsize; /* Choose the correct place to write the keys */ if (write_hierarchical) { pathsize = strlen(dev->nodename) + 10; path = kzalloc(pathsize, GFP_KERNEL); if (!path) { err = -ENOMEM; message = "out of memory while writing ring references"; goto error; } snprintf(path, pathsize, "%s/queue-%u", dev->nodename, queue->id); } else { path = (char *)dev->nodename; } /* Write ring references */ err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u", queue->tx_ring_ref); if (err) { message = "writing tx-ring-ref"; goto error; } err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u", queue->rx_ring_ref); if (err) { message = "writing rx-ring-ref"; goto error; } /* Write event channels; taking into account both shared * and split event channel scenarios. */ if (queue->tx_evtchn == queue->rx_evtchn) { /* Shared event channel */ err = xenbus_printf(*xbt, path, "event-channel", "%u", queue->tx_evtchn); if (err) { message = "writing event-channel"; goto error; } } else { /* Split event channels */ err = xenbus_printf(*xbt, path, "event-channel-tx", "%u", queue->tx_evtchn); if (err) { message = "writing event-channel-tx"; goto error; } err = xenbus_printf(*xbt, path, "event-channel-rx", "%u", queue->rx_evtchn); if (err) { message = "writing event-channel-rx"; goto error; } } if (write_hierarchical) kfree(path); return 0; error: if (write_hierarchical) kfree(path); xenbus_dev_fatal(dev, err, "%s", message); return err; } static void xennet_destroy_queues(struct netfront_info *info) { unsigned int i; for (i = 0; i < info->netdev->real_num_tx_queues; i++) { struct netfront_queue *queue = &info->queues[i]; if (netif_running(info->netdev)) napi_disable(&queue->napi); netif_napi_del(&queue->napi); } kfree(info->queues); info->queues = NULL; } static int xennet_create_queues(struct netfront_info *info, unsigned int *num_queues) { unsigned int i; int ret; info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue), GFP_KERNEL); if (!info->queues) return -ENOMEM; for (i = 0; i < *num_queues; i++) { struct netfront_queue *queue = &info->queues[i]; queue->id = i; queue->info = info; ret = xennet_init_queue(queue); if (ret < 0) { dev_warn(&info->xbdev->dev, "only created %d queues\n", i); *num_queues = i; break; } netif_napi_add(queue->info->netdev, &queue->napi, xennet_poll, 64); if (netif_running(info->netdev)) napi_enable(&queue->napi); } netif_set_real_num_tx_queues(info->netdev, *num_queues); if (*num_queues == 0) { dev_err(&info->xbdev->dev, "no queues\n"); return -EINVAL; } return 0; } /* Common code used when first setting up, and when resuming. */ static int talk_to_netback(struct xenbus_device *dev, struct netfront_info *info) { const char *message; struct xenbus_transaction xbt; int err; unsigned int feature_split_evtchn; unsigned int i = 0; unsigned int max_queues = 0; struct netfront_queue *queue = NULL; unsigned int num_queues = 1; info->netdev->irq = 0; /* Check if backend supports multiple queues */ max_queues = xenbus_read_unsigned(info->xbdev->otherend, "multi-queue-max-queues", 1); num_queues = min(max_queues, xennet_max_queues); /* Check feature-split-event-channels */ feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend, "feature-split-event-channels", 0); /* Read mac addr. */ err = xen_net_read_mac(dev, info->netdev->dev_addr); if (err) { xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); goto out_unlocked; } rtnl_lock(); if (info->queues) xennet_destroy_queues(info); err = xennet_create_queues(info, &num_queues); if (err < 0) { xenbus_dev_fatal(dev, err, "creating queues"); kfree(info->queues); info->queues = NULL; goto out; } rtnl_unlock(); /* Create shared ring, alloc event channel -- for each queue */ for (i = 0; i < num_queues; ++i) { queue = &info->queues[i]; err = setup_netfront(dev, queue, feature_split_evtchn); if (err) goto destroy_ring; } again: err = xenbus_transaction_start(&xbt); if (err) { xenbus_dev_fatal(dev, err, "starting transaction"); goto destroy_ring; } if (xenbus_exists(XBT_NIL, info->xbdev->otherend, "multi-queue-max-queues")) { /* Write the number of queues */ err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues", "%u", num_queues); if (err) { message = "writing multi-queue-num-queues"; goto abort_transaction_no_dev_fatal; } } if (num_queues == 1) { err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */ if (err) goto abort_transaction_no_dev_fatal; } else { /* Write the keys for each queue */ for (i = 0; i < num_queues; ++i) { queue = &info->queues[i]; err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */ if (err) goto abort_transaction_no_dev_fatal; } } /* The remaining keys are not queue-specific */ err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", 1); if (err) { message = "writing request-rx-copy"; goto abort_transaction; } err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); if (err) { message = "writing feature-rx-notify"; goto abort_transaction; } err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); if (err) { message = "writing feature-sg"; goto abort_transaction; } err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); if (err) { message = "writing feature-gso-tcpv4"; goto abort_transaction; } err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1"); if (err) { message = "writing feature-gso-tcpv6"; goto abort_transaction; } err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload", "1"); if (err) { message = "writing feature-ipv6-csum-offload"; goto abort_transaction; } err = xenbus_transaction_end(xbt, 0); if (err) { if (err == -EAGAIN) goto again; xenbus_dev_fatal(dev, err, "completing transaction"); goto destroy_ring; } return 0; abort_transaction: xenbus_dev_fatal(dev, err, "%s", message); abort_transaction_no_dev_fatal: xenbus_transaction_end(xbt, 1); destroy_ring: xennet_disconnect_backend(info); rtnl_lock(); xennet_destroy_queues(info); out: rtnl_unlock(); out_unlocked: device_unregister(&dev->dev); return err; } static int xennet_connect(struct net_device *dev) { struct netfront_info *np = netdev_priv(dev); unsigned int num_queues = 0; int err; unsigned int j = 0; struct netfront_queue *queue = NULL; if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) { dev_info(&dev->dev, "backend does not support copying receive path\n"); return -ENODEV; } err = talk_to_netback(np->xbdev, np); if (err) return err; /* talk_to_netback() sets the correct number of queues */ num_queues = dev->real_num_tx_queues; if (dev->reg_state == NETREG_UNINITIALIZED) { err = register_netdev(dev); if (err) { pr_warn("%s: register_netdev err=%d\n", __func__, err); device_unregister(&np->xbdev->dev); return err; } } rtnl_lock(); netdev_update_features(dev); rtnl_unlock(); /* * All public and private state should now be sane. Get * ready to start sending and receiving packets and give the driver * domain a kick because we've probably just requeued some * packets. */ netif_carrier_on(np->netdev); for (j = 0; j < num_queues; ++j) { queue = &np->queues[j]; notify_remote_via_irq(queue->tx_irq); if (queue->tx_irq != queue->rx_irq) notify_remote_via_irq(queue->rx_irq); spin_lock_irq(&queue->tx_lock); xennet_tx_buf_gc(queue); spin_unlock_irq(&queue->tx_lock); spin_lock_bh(&queue->rx_lock); xennet_alloc_rx_buffers(queue); spin_unlock_bh(&queue->rx_lock); } return 0; } /** * Callback received when the backend's state changes. */ static void netback_changed(struct xenbus_device *dev, enum xenbus_state backend_state) { struct netfront_info *np = dev_get_drvdata(&dev->dev); struct net_device *netdev = np->netdev; dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); wake_up_all(&module_wq); switch (backend_state) { case XenbusStateInitialising: case XenbusStateInitialised: case XenbusStateReconfiguring: case XenbusStateReconfigured: case XenbusStateUnknown: break; case XenbusStateInitWait: if (dev->state != XenbusStateInitialising) break; if (xennet_connect(netdev) != 0) break; xenbus_switch_state(dev, XenbusStateConnected); break; case XenbusStateConnected: netdev_notify_peers(netdev); break; case XenbusStateClosed: if (dev->state == XenbusStateClosed) break; /* Missed the backend's CLOSING state -- fallthrough */ case XenbusStateClosing: xenbus_frontend_closed(dev); break; } } static const struct xennet_stat { char name[ETH_GSTRING_LEN]; u16 offset; } xennet_stats[] = { { "rx_gso_checksum_fixup", offsetof(struct netfront_info, rx_gso_checksum_fixup) }, }; static int xennet_get_sset_count(struct net_device *dev, int string_set) { switch (string_set) { case ETH_SS_STATS: return ARRAY_SIZE(xennet_stats); default: return -EINVAL; } } static void xennet_get_ethtool_stats(struct net_device *dev, struct ethtool_stats *stats, u64 * data) { void *np = netdev_priv(dev); int i; for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset)); } static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) { int i; switch (stringset) { case ETH_SS_STATS: for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) memcpy(data + i * ETH_GSTRING_LEN, xennet_stats[i].name, ETH_GSTRING_LEN); break; } } static const struct ethtool_ops xennet_ethtool_ops = { .get_link = ethtool_op_get_link, .get_sset_count = xennet_get_sset_count, .get_ethtool_stats = xennet_get_ethtool_stats, .get_strings = xennet_get_strings, }; #ifdef CONFIG_SYSFS static ssize_t show_rxbuf(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "%lu\n", NET_RX_RING_SIZE); } static ssize_t store_rxbuf(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { char *endp; unsigned long target; if (!capable(CAP_NET_ADMIN)) return -EPERM; target = simple_strtoul(buf, &endp, 0); if (endp == buf) return -EBADMSG; /* rxbuf_min and rxbuf_max are no longer configurable. */ return len; } static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf); static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf); static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL); static struct attribute *xennet_dev_attrs[] = { &dev_attr_rxbuf_min.attr, &dev_attr_rxbuf_max.attr, &dev_attr_rxbuf_cur.attr, NULL }; static const struct attribute_group xennet_dev_group = { .attrs = xennet_dev_attrs }; #endif /* CONFIG_SYSFS */ static int xennet_remove(struct xenbus_device *dev) { struct netfront_info *info = dev_get_drvdata(&dev->dev); dev_dbg(&dev->dev, "%s\n", dev->nodename); if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) { xenbus_switch_state(dev, XenbusStateClosing); wait_event(module_wq, xenbus_read_driver_state(dev->otherend) == XenbusStateClosing || xenbus_read_driver_state(dev->otherend) == XenbusStateUnknown); xenbus_switch_state(dev, XenbusStateClosed); wait_event(module_wq, xenbus_read_driver_state(dev->otherend) == XenbusStateClosed || xenbus_read_driver_state(dev->otherend) == XenbusStateUnknown); } xennet_disconnect_backend(info); if (info->netdev->reg_state == NETREG_REGISTERED) unregister_netdev(info->netdev); if (info->queues) { rtnl_lock(); xennet_destroy_queues(info); rtnl_unlock(); } xennet_free_netdev(info->netdev); return 0; } static const struct xenbus_device_id netfront_ids[] = { { "vif" }, { "" } }; static struct xenbus_driver netfront_driver = { .ids = netfront_ids, .probe = netfront_probe, .remove = xennet_remove, .resume = netfront_resume, .otherend_changed = netback_changed, }; static int __init netif_init(void) { if (!xen_domain()) return -ENODEV; if (!xen_has_pv_nic_devices()) return -ENODEV; pr_info("Initialising Xen virtual ethernet driver\n"); /* Allow as many queues as there are CPUs inut max. 8 if user has not * specified a value. */ if (xennet_max_queues == 0) xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT, num_online_cpus()); return xenbus_register_frontend(&netfront_driver); } module_init(netif_init); static void __exit netif_exit(void) { xenbus_unregister_driver(&netfront_driver); } module_exit(netif_exit); MODULE_DESCRIPTION("Xen virtual network device frontend"); MODULE_LICENSE("GPL"); MODULE_ALIAS("xen:vif"); MODULE_ALIAS("xennet");