/* * 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 #include 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, PAGE_SIZE) #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE) #define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256) struct netfront_stats { u64 rx_packets; u64 tx_packets; u64 rx_bytes; u64 tx_bytes; struct u64_stats_sync syncp; }; struct netfront_info { struct list_head list; struct net_device *netdev; 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[IFNAMSIZ+4]; /* DEVNAME-tx */ char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */ struct xenbus_device *xbdev; 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; /* Receive-ring batched refills. */ #define RX_MIN_TARGET 8 #define RX_DFL_MIN_TARGET 64 #define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) unsigned rx_min_target, rx_max_target, rx_target; struct sk_buff_head rx_batch; 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]; unsigned long rx_pfn_array[NET_RX_RING_SIZE]; struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1]; struct mmu_update rx_mmu[NET_RX_RING_SIZE]; /* Statistics */ struct netfront_stats __percpu *stats; unsigned long 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_info *np, RING_IDX ri) { int i = xennet_rxidx(ri); struct sk_buff *skb = np->rx_skbs[i]; np->rx_skbs[i] = NULL; return skb; } static grant_ref_t xennet_get_rx_ref(struct netfront_info *np, RING_IDX ri) { int i = xennet_rxidx(ri); grant_ref_t ref = np->grant_rx_ref[i]; np->grant_rx_ref[i] = GRANT_INVALID_REF; return ref; } #ifdef CONFIG_SYSFS static int xennet_sysfs_addif(struct net_device *netdev); static void xennet_sysfs_delif(struct net_device *netdev); #else /* !CONFIG_SYSFS */ #define xennet_sysfs_addif(dev) (0) #define xennet_sysfs_delif(dev) do { } while (0) #endif static bool xennet_can_sg(struct net_device *dev) { return dev->features & NETIF_F_SG; } static void rx_refill_timeout(unsigned long data) { struct net_device *dev = (struct net_device *)data; struct netfront_info *np = netdev_priv(dev); napi_schedule(&np->napi); } static int netfront_tx_slot_available(struct netfront_info *np) { return (np->tx.req_prod_pvt - np->tx.rsp_cons) < (TX_MAX_TARGET - MAX_SKB_FRAGS - 2); } static void xennet_maybe_wake_tx(struct net_device *dev) { struct netfront_info *np = netdev_priv(dev); if (unlikely(netif_queue_stopped(dev)) && netfront_tx_slot_available(np) && likely(netif_running(dev))) netif_wake_queue(dev); } static void xennet_alloc_rx_buffers(struct net_device *dev) { unsigned short id; struct netfront_info *np = netdev_priv(dev); struct sk_buff *skb; struct page *page; int i, batch_target, notify; RING_IDX req_prod = np->rx.req_prod_pvt; grant_ref_t ref; unsigned long pfn; void *vaddr; struct xen_netif_rx_request *req; if (unlikely(!netif_carrier_ok(dev))) return; /* * Allocate skbuffs greedily, even though we batch updates to the * receive ring. This creates a less bursty demand on the memory * allocator, so should reduce the chance of failed allocation requests * both for ourself and for other kernel subsystems. */ batch_target = np->rx_target - (req_prod - np->rx.rsp_cons); for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) { skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!skb)) goto no_skb; /* Align ip header to a 16 bytes boundary */ skb_reserve(skb, NET_IP_ALIGN); page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); if (!page) { kfree_skb(skb); no_skb: /* Could not allocate any skbuffs. Try again later. */ mod_timer(&np->rx_refill_timer, jiffies + (HZ/10)); /* Any skbuffs queued for refill? Force them out. */ if (i != 0) goto refill; break; } skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE); __skb_queue_tail(&np->rx_batch, skb); } /* Is the batch large enough to be worthwhile? */ if (i < (np->rx_target/2)) { if (req_prod > np->rx.sring->req_prod) goto push; return; } /* Adjust our fill target if we risked running out of buffers. */ if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) && ((np->rx_target *= 2) > np->rx_max_target)) np->rx_target = np->rx_max_target; refill: for (i = 0; ; i++) { skb = __skb_dequeue(&np->rx_batch); if (skb == NULL) break; skb->dev = dev; id = xennet_rxidx(req_prod + i); BUG_ON(np->rx_skbs[id]); np->rx_skbs[id] = skb; ref = gnttab_claim_grant_reference(&np->gref_rx_head); BUG_ON((signed short)ref < 0); np->grant_rx_ref[id] = ref; pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0])); vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0])); req = RING_GET_REQUEST(&np->rx, req_prod + i); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, pfn_to_mfn(pfn), 0); req->id = id; req->gref = ref; } wmb(); /* barrier so backend seens requests */ /* Above is a suitable barrier to ensure backend will see requests. */ np->rx.req_prod_pvt = req_prod + i; push: RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify); if (notify) notify_remote_via_irq(np->rx_irq); } static int xennet_open(struct net_device *dev) { struct netfront_info *np = netdev_priv(dev); napi_enable(&np->napi); spin_lock_bh(&np->rx_lock); if (netif_carrier_ok(dev)) { xennet_alloc_rx_buffers(dev); np->rx.sring->rsp_event = np->rx.rsp_cons + 1; if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) napi_schedule(&np->napi); } spin_unlock_bh(&np->rx_lock); netif_start_queue(dev); return 0; } static void xennet_tx_buf_gc(struct net_device *dev) { RING_IDX cons, prod; unsigned short id; struct netfront_info *np = netdev_priv(dev); struct sk_buff *skb; BUG_ON(!netif_carrier_ok(dev)); do { prod = np->tx.sring->rsp_prod; rmb(); /* Ensure we see responses up to 'rp'. */ for (cons = np->tx.rsp_cons; cons != prod; cons++) { struct xen_netif_tx_response *txrsp; txrsp = RING_GET_RESPONSE(&np->tx, cons); if (txrsp->status == XEN_NETIF_RSP_NULL) continue; id = txrsp->id; skb = np->tx_skbs[id].skb; if (unlikely(gnttab_query_foreign_access( np->grant_tx_ref[id]) != 0)) { pr_alert("%s: warning -- grant still in use by backend domain\n", __func__); BUG(); } gnttab_end_foreign_access_ref( np->grant_tx_ref[id], GNTMAP_readonly); gnttab_release_grant_reference( &np->gref_tx_head, np->grant_tx_ref[id]); np->grant_tx_ref[id] = GRANT_INVALID_REF; np->grant_tx_page[id] = NULL; add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id); dev_kfree_skb_irq(skb); } np->tx.rsp_cons = prod; /* * Set a new event, then check for race with update of tx_cons. * Note that it is essential to schedule a callback, no matter * how few buffers are pending. Even if there is space in the * transmit ring, higher layers may be blocked because too much * data is outstanding: in such cases notification from Xen is * likely to be the only kick that we'll get. */ np->tx.sring->rsp_event = prod + ((np->tx.sring->req_prod - prod) >> 1) + 1; mb(); /* update shared area */ } while ((cons == prod) && (prod != np->tx.sring->rsp_prod)); xennet_maybe_wake_tx(dev); } static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, struct xen_netif_tx_request *tx) { struct netfront_info *np = netdev_priv(dev); char *data = skb->data; unsigned long mfn; RING_IDX prod = np->tx.req_prod_pvt; int frags = skb_shinfo(skb)->nr_frags; unsigned int offset = offset_in_page(data); unsigned int len = skb_headlen(skb); unsigned int id; grant_ref_t ref; int i; /* While the header overlaps a page boundary (including being larger than a page), split it it into page-sized chunks. */ while (len > PAGE_SIZE - offset) { tx->size = PAGE_SIZE - offset; tx->flags |= XEN_NETTXF_more_data; len -= tx->size; data += tx->size; offset = 0; id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); np->tx_skbs[id].skb = skb_get(skb); tx = RING_GET_REQUEST(&np->tx, prod++); tx->id = id; ref = gnttab_claim_grant_reference(&np->gref_tx_head); BUG_ON((signed short)ref < 0); mfn = virt_to_mfn(data); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); np->grant_tx_page[id] = virt_to_page(data); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = len; tx->flags = 0; } /* Grant backend access to each skb fragment page. */ for (i = 0; i < frags; i++) { skb_frag_t *frag = skb_shinfo(skb)->frags + i; struct page *page = skb_frag_page(frag); len = skb_frag_size(frag); offset = frag->page_offset; /* Data must not cross a page boundary. */ BUG_ON(len + offset > PAGE_SIZE<> PAGE_SHIFT; offset &= ~PAGE_MASK; while (len > 0) { unsigned long bytes; BUG_ON(offset >= PAGE_SIZE); bytes = PAGE_SIZE - offset; if (bytes > len) bytes = len; tx->flags |= XEN_NETTXF_more_data; id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); np->tx_skbs[id].skb = skb_get(skb); tx = RING_GET_REQUEST(&np->tx, prod++); tx->id = id; ref = gnttab_claim_grant_reference(&np->gref_tx_head); BUG_ON((signed short)ref < 0); mfn = pfn_to_mfn(page_to_pfn(page)); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); np->grant_tx_page[id] = page; tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = bytes; tx->flags = 0; offset += bytes; len -= bytes; /* Next frame */ if (offset == PAGE_SIZE && len) { BUG_ON(!PageCompound(page)); page++; offset = 0; } } } np->tx.req_prod_pvt = prod; } /* * Count how many ring slots are required to send the frags of this * skb. Each frag might be a compound page. */ static int xennet_count_skb_frag_slots(struct sk_buff *skb) { int i, frags = skb_shinfo(skb)->nr_frags; int pages = 0; 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; pages += PFN_UP(offset + size); } return pages; } static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) { unsigned short id; struct netfront_info *np = netdev_priv(dev); struct netfront_stats *stats = this_cpu_ptr(np->stats); struct xen_netif_tx_request *tx; char *data = skb->data; RING_IDX i; grant_ref_t ref; unsigned long mfn; int notify; int slots; unsigned int offset = offset_in_page(data); unsigned int len = skb_headlen(skb); unsigned long flags; /* 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 = DIV_ROUND_UP(offset + len, PAGE_SIZE) + xennet_count_skb_frag_slots(skb); if (unlikely(slots > MAX_SKB_FRAGS + 1)) { net_alert_ratelimited( "xennet: skb rides the rocket: %d slots\n", slots); goto drop; } spin_lock_irqsave(&np->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(&np->tx_lock, flags); goto drop; } i = np->tx.req_prod_pvt; id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); np->tx_skbs[id].skb = skb; tx = RING_GET_REQUEST(&np->tx, i); tx->id = id; ref = gnttab_claim_grant_reference(&np->gref_tx_head); BUG_ON((signed short)ref < 0); mfn = virt_to_mfn(data); gnttab_grant_foreign_access_ref( ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); np->grant_tx_page[id] = virt_to_page(data); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = len; tx->flags = 0; 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; if (skb_shinfo(skb)->gso_size) { struct xen_netif_extra_info *gso; gso = (struct xen_netif_extra_info *) RING_GET_REQUEST(&np->tx, ++i); 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; } np->tx.req_prod_pvt = i + 1; xennet_make_frags(skb, dev, tx); tx->size = skb->len; RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify); if (notify) notify_remote_via_irq(np->tx_irq); u64_stats_update_begin(&stats->syncp); stats->tx_bytes += skb->len; stats->tx_packets++; u64_stats_update_end(&stats->syncp); /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ xennet_tx_buf_gc(dev); if (!netfront_tx_slot_available(np)) netif_stop_queue(dev); spin_unlock_irqrestore(&np->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); netif_stop_queue(np->netdev); napi_disable(&np->napi); return 0; } static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb, grant_ref_t ref) { int new = xennet_rxidx(np->rx.req_prod_pvt); BUG_ON(np->rx_skbs[new]); np->rx_skbs[new] = skb; np->grant_rx_ref[new] = ref; RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new; RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref; np->rx.req_prod_pvt++; } static int xennet_get_extras(struct netfront_info *np, struct xen_netif_extra_info *extras, RING_IDX rp) { struct xen_netif_extra_info *extra; struct device *dev = &np->netdev->dev; RING_IDX cons = np->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(&np->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(np, cons); ref = xennet_get_rx_ref(np, cons); xennet_move_rx_slot(np, skb, ref); } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); np->rx.rsp_cons = cons; return err; } static int xennet_get_responses(struct netfront_info *np, 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 = &np->netdev->dev; RING_IDX cons = np->rx.rsp_cons; struct sk_buff *skb = xennet_get_rx_skb(np, cons); grant_ref_t ref = xennet_get_rx_ref(np, cons); int max = MAX_SKB_FRAGS + (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(np, extras, rp); cons = np->rx.rsp_cons; } for (;;) { if (unlikely(rx->status < 0 || rx->offset + rx->status > PAGE_SIZE)) { if (net_ratelimit()) dev_warn(dev, "rx->offset: %x, size: %u\n", rx->offset, rx->status); xennet_move_rx_slot(np, 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(&np->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(&np->rx, cons + slots); skb = xennet_get_rx_skb(np, cons + slots); ref = xennet_get_rx_ref(np, cons + slots); slots++; } if (unlikely(slots > max)) { if (net_ratelimit()) dev_warn(dev, "Too many slots\n"); err = -E2BIG; } if (unlikely(err)) np->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_info *np, struct sk_buff *skb, struct sk_buff_head *list) { struct skb_shared_info *shinfo = skb_shinfo(skb); RING_IDX cons = np->rx.rsp_cons; struct sk_buff *nskb; while ((nskb = __skb_dequeue(list))) { struct xen_netif_rx_response *rx = RING_GET_RESPONSE(&np->rx, ++cons); skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; if (shinfo->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)); } BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS); skb_add_rx_frag(skb, shinfo->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); 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 net_device *dev, struct sk_buff_head *rxq) { struct netfront_info *np = netdev_priv(dev); struct netfront_stats *stats = this_cpu_ptr(np->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, dev); skb_reset_network_header(skb); if (checksum_setup(dev, skb)) { kfree_skb(skb); packets_dropped++; dev->stats.rx_errors++; continue; } u64_stats_update_begin(&stats->syncp); stats->rx_packets++; stats->rx_bytes += skb->len; u64_stats_update_end(&stats->syncp); /* Pass it up. */ napi_gro_receive(&np->napi, skb); } return packets_dropped; } static int xennet_poll(struct napi_struct *napi, int budget) { struct netfront_info *np = container_of(napi, struct netfront_info, napi); struct net_device *dev = np->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; unsigned long flags; int err; spin_lock(&np->rx_lock); skb_queue_head_init(&rxq); skb_queue_head_init(&errq); skb_queue_head_init(&tmpq); rp = np->rx.sring->rsp_prod; rmb(); /* Ensure we see queued responses up to 'rp'. */ i = np->rx.rsp_cons; work_done = 0; while ((i != rp) && (work_done < budget)) { memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx)); memset(extras, 0, sizeof(rinfo.extras)); err = xennet_get_responses(np, &rinfo, rp, &tmpq); if (unlikely(err)) { err: while ((skb = __skb_dequeue(&tmpq))) __skb_queue_tail(&errq, skb); dev->stats.rx_errors++; i = np->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); np->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(np, skb, &tmpq); 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); np->rx.rsp_cons = ++i; work_done++; } __skb_queue_purge(&errq); work_done -= handle_incoming_queue(dev, &rxq); /* If we get a callback with very few responses, reduce fill target. */ /* NB. Note exponential increase, linear decrease. */ if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) > ((3*np->rx_target) / 4)) && (--np->rx_target < np->rx_min_target)) np->rx_target = np->rx_min_target; xennet_alloc_rx_buffers(dev); if (work_done < budget) { int more_to_do = 0; napi_gro_flush(napi, false); local_irq_save(flags); RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do); if (!more_to_do) __napi_complete(napi); local_irq_restore(flags); } spin_unlock(&np->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 - MAX_TCP_HEADER : ETH_DATA_LEN; if (mtu > max) return -EINVAL; dev->mtu = mtu; return 0; } static struct rtnl_link_stats64 *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 *stats = per_cpu_ptr(np->stats, cpu); u64 rx_packets, rx_bytes, tx_packets, tx_bytes; unsigned int start; do { start = u64_stats_fetch_begin_irq(&stats->syncp); rx_packets = stats->rx_packets; tx_packets = stats->tx_packets; rx_bytes = stats->rx_bytes; tx_bytes = stats->tx_bytes; } while (u64_stats_fetch_retry_irq(&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; return tot; } static void xennet_release_tx_bufs(struct netfront_info *np) { 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(&np->tx_skbs[i])) continue; skb = np->tx_skbs[i].skb; get_page(np->grant_tx_page[i]); gnttab_end_foreign_access(np->grant_tx_ref[i], GNTMAP_readonly, (unsigned long)page_address(np->grant_tx_page[i])); np->grant_tx_page[i] = NULL; np->grant_tx_ref[i] = GRANT_INVALID_REF; add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i); dev_kfree_skb_irq(skb); } } static void xennet_release_rx_bufs(struct netfront_info *np) { int id, ref; spin_lock_bh(&np->rx_lock); for (id = 0; id < NET_RX_RING_SIZE; id++) { struct sk_buff *skb; struct page *page; skb = np->rx_skbs[id]; if (!skb) continue; ref = np->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)); np->grant_rx_ref[id] = GRANT_INVALID_REF; kfree_skb(skb); } spin_unlock_bh(&np->rx_lock); } static void xennet_uninit(struct net_device *dev) { struct netfront_info *np = netdev_priv(dev); xennet_release_tx_bufs(np); xennet_release_rx_bufs(np); gnttab_free_grant_references(np->gref_tx_head); gnttab_free_grant_references(np->gref_rx_head); } static netdev_features_t xennet_fix_features(struct net_device *dev, netdev_features_t features) { struct netfront_info *np = netdev_priv(dev); int val; if (features & NETIF_F_SG) { if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", "%d", &val) < 0) val = 0; if (!val) features &= ~NETIF_F_SG; } if (features & NETIF_F_IPV6_CSUM) { if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-ipv6-csum-offload", "%d", &val) < 0) val = 0; if (!val) features &= ~NETIF_F_IPV6_CSUM; } if (features & NETIF_F_TSO) { if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-gso-tcpv4", "%d", &val) < 0) val = 0; if (!val) features &= ~NETIF_F_TSO; } if (features & NETIF_F_TSO6) { if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-gso-tcpv6", "%d", &val) < 0) val = 0; if (!val) 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_info *np = dev_id; struct net_device *dev = np->netdev; unsigned long flags; spin_lock_irqsave(&np->tx_lock, flags); xennet_tx_buf_gc(dev); spin_unlock_irqrestore(&np->tx_lock, flags); return IRQ_HANDLED; } static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) { struct netfront_info *np = dev_id; struct net_device *dev = np->netdev; if (likely(netif_carrier_ok(dev) && RING_HAS_UNCONSUMED_RESPONSES(&np->rx))) napi_schedule(&np->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) { xennet_interrupt(0, dev); } #endif static const struct net_device_ops xennet_netdev_ops = { .ndo_open = xennet_open, .ndo_uninit = xennet_uninit, .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, #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = xennet_poll_controller, #endif }; static struct net_device *xennet_create_dev(struct xenbus_device *dev) { int i, err; struct net_device *netdev; struct netfront_info *np; netdev = alloc_etherdev(sizeof(struct netfront_info)); if (!netdev) return ERR_PTR(-ENOMEM); np = netdev_priv(netdev); np->xbdev = dev; spin_lock_init(&np->tx_lock); spin_lock_init(&np->rx_lock); skb_queue_head_init(&np->rx_batch); np->rx_target = RX_DFL_MIN_TARGET; np->rx_min_target = RX_DFL_MIN_TARGET; np->rx_max_target = RX_MAX_TARGET; init_timer(&np->rx_refill_timer); np->rx_refill_timer.data = (unsigned long)netdev; np->rx_refill_timer.function = rx_refill_timeout; err = -ENOMEM; np->stats = netdev_alloc_pcpu_stats(struct netfront_stats); if (np->stats == NULL) goto exit; /* Initialise tx_skbs as a free chain containing every entry. */ np->tx_skb_freelist = 0; for (i = 0; i < NET_TX_RING_SIZE; i++) { skb_entry_set_link(&np->tx_skbs[i], i+1); np->grant_tx_ref[i] = GRANT_INVALID_REF; np->grant_tx_page[i] = NULL; } /* Clear out rx_skbs */ for (i = 0; i < NET_RX_RING_SIZE; i++) { np->rx_skbs[i] = NULL; np->grant_rx_ref[i] = GRANT_INVALID_REF; } /* A grant for every tx ring slot */ if (gnttab_alloc_grant_references(TX_MAX_TARGET, &np->gref_tx_head) < 0) { pr_alert("can't alloc tx grant refs\n"); err = -ENOMEM; goto exit_free_stats; } /* A grant for every rx ring slot */ if (gnttab_alloc_grant_references(RX_MAX_TARGET, &np->gref_rx_head) < 0) { pr_alert("can't alloc rx grant refs\n"); err = -ENOMEM; goto exit_free_tx; } netdev->netdev_ops = &xennet_netdev_ops; netif_napi_add(netdev, &np->napi, xennet_poll, 64); 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; SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops); SET_NETDEV_DEV(netdev, &dev->dev); netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER); np->netdev = netdev; netif_carrier_off(netdev); return netdev; exit_free_tx: gnttab_free_grant_references(np->gref_tx_head); exit_free_stats: free_percpu(np->stats); exit: 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); err = register_netdev(info->netdev); if (err) { pr_warn("%s: register_netdev err=%d\n", __func__, err); goto fail; } err = xennet_sysfs_addif(info->netdev); if (err) { unregister_netdev(info->netdev); pr_warn("%s: add sysfs failed err=%d\n", __func__, err); goto fail; } return 0; fail: free_netdev(netdev); dev_set_drvdata(&dev->dev, NULL); return err; } 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) { /* Stop old i/f to prevent errors whilst we rebuild the state. */ spin_lock_bh(&info->rx_lock); spin_lock_irq(&info->tx_lock); netif_carrier_off(info->netdev); spin_unlock_irq(&info->tx_lock); spin_unlock_bh(&info->rx_lock); if (info->tx_irq && (info->tx_irq == info->rx_irq)) unbind_from_irqhandler(info->tx_irq, info); if (info->tx_irq && (info->tx_irq != info->rx_irq)) { unbind_from_irqhandler(info->tx_irq, info); unbind_from_irqhandler(info->rx_irq, info); } info->tx_evtchn = info->rx_evtchn = 0; info->tx_irq = info->rx_irq = 0; /* End access and free the pages */ xennet_end_access(info->tx_ring_ref, info->tx.sring); xennet_end_access(info->rx_ring_ref, info->rx.sring); info->tx_ring_ref = GRANT_INVALID_REF; info->rx_ring_ref = GRANT_INVALID_REF; info->tx.sring = NULL; info->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_info *info) { int err; err = xenbus_alloc_evtchn(info->xbdev, &info->tx_evtchn); if (err < 0) goto fail; err = bind_evtchn_to_irqhandler(info->tx_evtchn, xennet_interrupt, 0, info->netdev->name, info); if (err < 0) goto bind_fail; info->rx_evtchn = info->tx_evtchn; info->rx_irq = info->tx_irq = err; return 0; bind_fail: xenbus_free_evtchn(info->xbdev, info->tx_evtchn); info->tx_evtchn = 0; fail: return err; } static int setup_netfront_split(struct netfront_info *info) { int err; err = xenbus_alloc_evtchn(info->xbdev, &info->tx_evtchn); if (err < 0) goto fail; err = xenbus_alloc_evtchn(info->xbdev, &info->rx_evtchn); if (err < 0) goto alloc_rx_evtchn_fail; snprintf(info->tx_irq_name, sizeof(info->tx_irq_name), "%s-tx", info->netdev->name); err = bind_evtchn_to_irqhandler(info->tx_evtchn, xennet_tx_interrupt, 0, info->tx_irq_name, info); if (err < 0) goto bind_tx_fail; info->tx_irq = err; snprintf(info->rx_irq_name, sizeof(info->rx_irq_name), "%s-rx", info->netdev->name); err = bind_evtchn_to_irqhandler(info->rx_evtchn, xennet_rx_interrupt, 0, info->rx_irq_name, info); if (err < 0) goto bind_rx_fail; info->rx_irq = err; return 0; bind_rx_fail: unbind_from_irqhandler(info->tx_irq, info); info->tx_irq = 0; bind_tx_fail: xenbus_free_evtchn(info->xbdev, info->rx_evtchn); info->rx_evtchn = 0; alloc_rx_evtchn_fail: xenbus_free_evtchn(info->xbdev, info->tx_evtchn); info->tx_evtchn = 0; fail: return err; } static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) { struct xen_netif_tx_sring *txs; struct xen_netif_rx_sring *rxs; int err; struct net_device *netdev = info->netdev; unsigned int feature_split_evtchn; info->tx_ring_ref = GRANT_INVALID_REF; info->rx_ring_ref = GRANT_INVALID_REF; info->rx.sring = NULL; info->tx.sring = NULL; netdev->irq = 0; err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, "feature-split-event-channels", "%u", &feature_split_evtchn); if (err < 0) feature_split_evtchn = 0; err = xen_net_read_mac(dev, netdev->dev_addr); if (err) { xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); goto fail; } 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(&info->tx, txs, PAGE_SIZE); err = xenbus_grant_ring(dev, virt_to_mfn(txs)); if (err < 0) goto grant_tx_ring_fail; info->tx_ring_ref = err; 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(&info->rx, rxs, PAGE_SIZE); err = xenbus_grant_ring(dev, virt_to_mfn(rxs)); if (err < 0) goto grant_rx_ring_fail; info->rx_ring_ref = err; if (feature_split_evtchn) err = setup_netfront_split(info); /* 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(info); 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(info->rx_ring_ref, 0); grant_rx_ring_fail: free_page((unsigned long)rxs); alloc_rx_ring_fail: gnttab_end_foreign_access_ref(info->tx_ring_ref, 0); grant_tx_ring_fail: free_page((unsigned long)txs); fail: return err; } /* 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; /* Create shared ring, alloc event channel. */ err = setup_netfront(dev, info); if (err) goto out; again: err = xenbus_transaction_start(&xbt); if (err) { xenbus_dev_fatal(dev, err, "starting transaction"); goto destroy_ring; } err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u", info->tx_ring_ref); if (err) { message = "writing tx ring-ref"; goto abort_transaction; } err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u", info->rx_ring_ref); if (err) { message = "writing rx ring-ref"; goto abort_transaction; } if (info->tx_evtchn == info->rx_evtchn) { err = xenbus_printf(xbt, dev->nodename, "event-channel", "%u", info->tx_evtchn); if (err) { message = "writing event-channel"; goto abort_transaction; } } else { err = xenbus_printf(xbt, dev->nodename, "event-channel-tx", "%u", info->tx_evtchn); if (err) { message = "writing event-channel-tx"; goto abort_transaction; } err = xenbus_printf(xbt, dev->nodename, "event-channel-rx", "%u", info->rx_evtchn); if (err) { message = "writing event-channel-rx"; goto abort_transaction; } } 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_transaction_end(xbt, 1); xenbus_dev_fatal(dev, err, "%s", message); destroy_ring: xennet_disconnect_backend(info); out: return err; } static int xennet_connect(struct net_device *dev) { struct netfront_info *np = netdev_priv(dev); int i, requeue_idx, err; struct sk_buff *skb; grant_ref_t ref; struct xen_netif_rx_request *req; unsigned int feature_rx_copy; err = xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-rx-copy", "%u", &feature_rx_copy); if (err != 1) feature_rx_copy = 0; if (!feature_rx_copy) { 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; rtnl_lock(); netdev_update_features(dev); rtnl_unlock(); spin_lock_bh(&np->rx_lock); spin_lock_irq(&np->tx_lock); /* Step 1: Discard all pending TX packet fragments. */ xennet_release_tx_bufs(np); /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */ for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) { skb_frag_t *frag; const struct page *page; if (!np->rx_skbs[i]) continue; skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i); ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i); req = RING_GET_REQUEST(&np->rx, requeue_idx); frag = &skb_shinfo(skb)->frags[0]; page = skb_frag_page(frag); gnttab_grant_foreign_access_ref( ref, np->xbdev->otherend_id, pfn_to_mfn(page_to_pfn(page)), 0); req->gref = ref; req->id = requeue_idx; requeue_idx++; } np->rx.req_prod_pvt = requeue_idx; /* * Step 3: 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); notify_remote_via_irq(np->tx_irq); if (np->tx_irq != np->rx_irq) notify_remote_via_irq(np->rx_irq); xennet_tx_buf_gc(dev); xennet_alloc_rx_buffers(dev); spin_unlock_irq(&np->tx_lock); spin_unlock_bh(&np->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)); 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] = *(unsigned long *)(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_min(struct device *dev, struct device_attribute *attr, char *buf) { struct net_device *netdev = to_net_dev(dev); struct netfront_info *info = netdev_priv(netdev); return sprintf(buf, "%u\n", info->rx_min_target); } static ssize_t store_rxbuf_min(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct net_device *netdev = to_net_dev(dev); struct netfront_info *np = netdev_priv(netdev); char *endp; unsigned long target; if (!capable(CAP_NET_ADMIN)) return -EPERM; target = simple_strtoul(buf, &endp, 0); if (endp == buf) return -EBADMSG; if (target < RX_MIN_TARGET) target = RX_MIN_TARGET; if (target > RX_MAX_TARGET) target = RX_MAX_TARGET; spin_lock_bh(&np->rx_lock); if (target > np->rx_max_target) np->rx_max_target = target; np->rx_min_target = target; if (target > np->rx_target) np->rx_target = target; xennet_alloc_rx_buffers(netdev); spin_unlock_bh(&np->rx_lock); return len; } static ssize_t show_rxbuf_max(struct device *dev, struct device_attribute *attr, char *buf) { struct net_device *netdev = to_net_dev(dev); struct netfront_info *info = netdev_priv(netdev); return sprintf(buf, "%u\n", info->rx_max_target); } static ssize_t store_rxbuf_max(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct net_device *netdev = to_net_dev(dev); struct netfront_info *np = netdev_priv(netdev); char *endp; unsigned long target; if (!capable(CAP_NET_ADMIN)) return -EPERM; target = simple_strtoul(buf, &endp, 0); if (endp == buf) return -EBADMSG; if (target < RX_MIN_TARGET) target = RX_MIN_TARGET; if (target > RX_MAX_TARGET) target = RX_MAX_TARGET; spin_lock_bh(&np->rx_lock); if (target < np->rx_min_target) np->rx_min_target = target; np->rx_max_target = target; if (target < np->rx_target) np->rx_target = target; xennet_alloc_rx_buffers(netdev); spin_unlock_bh(&np->rx_lock); return len; } static ssize_t show_rxbuf_cur(struct device *dev, struct device_attribute *attr, char *buf) { struct net_device *netdev = to_net_dev(dev); struct netfront_info *info = netdev_priv(netdev); return sprintf(buf, "%u\n", info->rx_target); } static struct device_attribute xennet_attrs[] = { __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min), __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max), __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL), }; static int xennet_sysfs_addif(struct net_device *netdev) { int i; int err; for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) { err = device_create_file(&netdev->dev, &xennet_attrs[i]); if (err) goto fail; } return 0; fail: while (--i >= 0) device_remove_file(&netdev->dev, &xennet_attrs[i]); return err; } static void xennet_sysfs_delif(struct net_device *netdev) { int i; for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) device_remove_file(&netdev->dev, &xennet_attrs[i]); } #endif /* CONFIG_SYSFS */ static const struct xenbus_device_id netfront_ids[] = { { "vif" }, { "" } }; 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); xennet_disconnect_backend(info); xennet_sysfs_delif(info->netdev); unregister_netdev(info->netdev); del_timer_sync(&info->rx_refill_timer); free_percpu(info->stats); free_netdev(info->netdev); return 0; } static DEFINE_XENBUS_DRIVER(netfront, , .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"); 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");