/* * 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. */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/skbuff.h> #include <linux/ethtool.h> #include <linux/if_ether.h> #include <linux/tcp.h> #include <linux/udp.h> #include <linux/moduleparam.h> #include <linux/mm.h> #include <net/ip.h> #include <xen/xenbus.h> #include <xen/events.h> #include <xen/page.h> #include <xen/grant_table.h> #include <xen/interface/io/netif.h> #include <xen/interface/memory.h> #include <xen/interface/grant_table.h> static struct ethtool_ops xennet_ethtool_ops; struct netfront_cb { struct page *page; unsigned offset; }; #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 __RING_SIZE((struct xen_netif_tx_sring *)0, PAGE_SIZE) #define NET_RX_RING_SIZE __RING_SIZE((struct xen_netif_rx_sring *)0, PAGE_SIZE) #define TX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) struct netfront_info { struct list_head list; struct net_device *netdev; struct napi_struct napi; unsigned int evtchn; 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 link; } tx_skbs[NET_TX_RING_SIZE]; grant_ref_t gref_tx_head; grant_ref_t grant_tx_ref[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]; }; struct netfront_rx_info { struct xen_netif_rx_response rx; struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; }; /* * Access macros for acquiring freeing slots in tx_skbs[]. */ static void add_id_to_freelist(unsigned *head, union skb_entry *list, unsigned short id) { list[id].link = *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 int 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); netif_rx_schedule(dev, &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, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!skb)) goto no_skb; page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); if (!page) { kfree_skb(skb); no_skb: /* Any skbuffs queued for refill? Force them out. */ if (i != 0) goto refill; /* Could not allocate any skbuffs. Try again later. */ mod_timer(&np->rx_refill_timer, jiffies + (HZ/10)); break; } skb_shinfo(skb)->frags[0].page = page; skb_shinfo(skb)->nr_frags = 1; __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_shinfo(skb)->frags[0].page); vaddr = page_address(skb_shinfo(skb)->frags[0].page); 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->netdev->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)) netif_rx_schedule(dev, &np->napi); } spin_unlock_bh(&np->rx_lock); xennet_maybe_wake_tx(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 == 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)) { printk(KERN_ALERT "xennet_tx_buf_gc: warning " "-- grant still in use by backend " "domain.\n"); 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; 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 |= 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); 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; tx->flags |= 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(frag->page)); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = frag->page_offset; tx->size = frag->size; tx->flags = 0; } np->tx.req_prod_pvt = prod; } static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) { unsigned short id; struct netfront_info *np = netdev_priv(dev); struct xen_netif_tx_request *tx; struct xen_netif_extra_info *extra; char *data = skb->data; RING_IDX i; grant_ref_t ref; unsigned long mfn; int notify; int frags = skb_shinfo(skb)->nr_frags; unsigned int offset = offset_in_page(data); unsigned int len = skb_headlen(skb); frags += (offset + len + PAGE_SIZE - 1) / PAGE_SIZE; if (unlikely(frags > MAX_SKB_FRAGS + 1)) { printk(KERN_ALERT "xennet: skb rides the rocket: %d frags\n", frags); dump_stack(); goto drop; } spin_lock_irq(&np->tx_lock); if (unlikely(!netif_carrier_ok(dev) || (frags > 1 && !xennet_can_sg(dev)) || netif_needs_gso(dev, skb))) { spin_unlock_irq(&np->tx_lock); 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); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = len; extra = NULL; tx->flags = 0; if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */ tx->flags |= NETTXF_csum_blank | NETTXF_data_validated; else if (skb->ip_summed == CHECKSUM_UNNECESSARY) /* remote but checksummed. */ tx->flags |= 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); if (extra) extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE; else tx->flags |= NETTXF_extra_info; gso->u.gso.size = skb_shinfo(skb)->gso_size; gso->u.gso.type = 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; extra = gso; } 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->netdev->irq); dev->stats.tx_bytes += skb->len; dev->stats.tx_packets++; /* 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_irq(&np->tx_lock); return 0; drop: dev->stats.tx_dropped++; dev_kfree_skb(skb); return 0; } 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 frags = 1; int err = 0; unsigned long ret; if (rx->flags & 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 backed. */ 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 & NETRXF_more_data)) break; if (cons + frags == rp) { if (net_ratelimit()) dev_warn(dev, "Need more frags\n"); err = -ENOENT; break; } rx = RING_GET_RESPONSE(&np->rx, cons + frags); skb = xennet_get_rx_skb(np, cons + frags); ref = xennet_get_rx_ref(np, cons + frags); frags++; } if (unlikely(frags > max)) { if (net_ratelimit()) dev_warn(dev, "Too many frags\n"); err = -E2BIG; } if (unlikely(err)) np->rx.rsp_cons = cons + frags; 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()) printk(KERN_WARNING "GSO size must not be zero.\n"); return -EINVAL; } /* Currently only TCPv4 S.O. is supported. */ if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) { if (net_ratelimit()) printk(KERN_WARNING "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 = SKB_GSO_TCPV4; /* 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); int nr_frags = shinfo->nr_frags; RING_IDX cons = np->rx.rsp_cons; skb_frag_t *frag = shinfo->frags + nr_frags; struct sk_buff *nskb; while ((nskb = __skb_dequeue(list))) { struct xen_netif_rx_response *rx = RING_GET_RESPONSE(&np->rx, ++cons); frag->page = skb_shinfo(nskb)->frags[0].page; frag->page_offset = rx->offset; frag->size = rx->status; skb->data_len += rx->status; skb_shinfo(nskb)->nr_frags = 0; kfree_skb(nskb); frag++; nr_frags++; } shinfo->nr_frags = nr_frags; return cons; } static int skb_checksum_setup(struct sk_buff *skb) { struct iphdr *iph; unsigned char *th; int err = -EPROTO; if (skb->protocol != htons(ETH_P_IP)) goto out; iph = (void *)skb->data; th = skb->data + 4 * iph->ihl; if (th >= skb_tail_pointer(skb)) goto out; skb->csum_start = th - skb->head; switch (iph->protocol) { case IPPROTO_TCP: skb->csum_offset = offsetof(struct tcphdr, check); break; case IPPROTO_UDP: skb->csum_offset = offsetof(struct udphdr, check); break; default: if (net_ratelimit()) printk(KERN_ERR "Attempting to checksum a non-" "TCP/UDP packet, dropping a protocol" " %d packet", iph->protocol); goto out; } if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb)) goto out; err = 0; out: return err; } static int handle_incoming_queue(struct net_device *dev, struct sk_buff_head *rxq) { int packets_dropped = 0; struct sk_buff *skb; while ((skb = __skb_dequeue(rxq)) != NULL) { struct page *page = NETFRONT_SKB_CB(skb)->page; void *vaddr = page_address(page); unsigned offset = NETFRONT_SKB_CB(skb)->offset; memcpy(skb->data, vaddr + offset, skb_headlen(skb)); if (page != skb_shinfo(skb)->frags[0].page) __free_page(page); /* Ethernet work: Delayed to here as it peeks the header. */ skb->protocol = eth_type_trans(skb, dev); if (skb->ip_summed == CHECKSUM_PARTIAL) { if (skb_checksum_setup(skb)) { kfree_skb(skb); packets_dropped++; dev->stats.rx_errors++; continue; } } dev->stats.rx_packets++; dev->stats.rx_bytes += skb->len; /* Pass it up. */ netif_receive_skb(skb); dev->last_rx = jiffies; } 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; unsigned int len; 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)->page = skb_shinfo(skb)->frags[0].page; NETFRONT_SKB_CB(skb)->offset = rx->offset; len = rx->status; if (len > RX_COPY_THRESHOLD) len = RX_COPY_THRESHOLD; skb_put(skb, len); if (rx->status > len) { skb_shinfo(skb)->frags[0].page_offset = rx->offset + len; skb_shinfo(skb)->frags[0].size = rx->status - len; skb->data_len = rx->status - len; } else { skb_shinfo(skb)->frags[0].page = NULL; skb_shinfo(skb)->nr_frags = 0; } i = xennet_fill_frags(np, skb, &tmpq); /* * Truesize approximates the size of true data plus * any supervisor overheads. Adding hypervisor * overheads has been shown to significantly reduce * achievable bandwidth with the default receive * buffer size. It is therefore not wise to account * for it here. * * After alloc_skb(RX_COPY_THRESHOLD), truesize is set * to RX_COPY_THRESHOLD + the supervisor * overheads. Here, we add the size of the data pulled * in xennet_fill_frags(). * * We also adjust for any unused space in the main * data area by subtracting (RX_COPY_THRESHOLD - * len). This is especially important with drivers * which split incoming packets into header and data, * using only 66 bytes of the main data area (see the * e1000 driver for example.) On such systems, * without this last adjustement, our achievable * receive throughout using the standard receive * buffer size was cut by 25%(!!!). */ skb->truesize += skb->data_len - (RX_COPY_THRESHOLD - len); skb->len += skb->data_len; if (rx->flags & NETRXF_csum_blank) skb->ip_summed = CHECKSUM_PARTIAL; else if (rx->flags & NETRXF_data_validated) skb->ip_summed = CHECKSUM_UNNECESSARY; __skb_queue_tail(&rxq, skb); np->rx.rsp_cons = ++i; work_done++; } while ((skb = __skb_dequeue(&errq))) kfree_skb(skb); 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; local_irq_save(flags); RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do); if (!more_to_do) __netif_rx_complete(dev, 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) ? 65535 - ETH_HLEN : ETH_DATA_LEN; if (mtu > max) return -EINVAL; dev->mtu = mtu; return 0; } 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 ((unsigned long)np->tx_skbs[i].skb < PAGE_OFFSET) continue; skb = np->tx_skbs[i].skb; gnttab_end_foreign_access_ref(np->grant_tx_ref[i], GNTMAP_readonly); gnttab_release_grant_reference(&np->gref_tx_head, np->grant_tx_ref[i]); 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) { struct mmu_update *mmu = np->rx_mmu; struct multicall_entry *mcl = np->rx_mcl; struct sk_buff_head free_list; struct sk_buff *skb; unsigned long mfn; int xfer = 0, noxfer = 0, unused = 0; int id, ref; dev_warn(&np->netdev->dev, "%s: fix me for copying receiver.\n", __func__); return; skb_queue_head_init(&free_list); spin_lock_bh(&np->rx_lock); for (id = 0; id < NET_RX_RING_SIZE; id++) { ref = np->grant_rx_ref[id]; if (ref == GRANT_INVALID_REF) { unused++; continue; } skb = np->rx_skbs[id]; mfn = gnttab_end_foreign_transfer_ref(ref); gnttab_release_grant_reference(&np->gref_rx_head, ref); np->grant_rx_ref[id] = GRANT_INVALID_REF; if (0 == mfn) { skb_shinfo(skb)->nr_frags = 0; dev_kfree_skb(skb); noxfer++; continue; } if (!xen_feature(XENFEAT_auto_translated_physmap)) { /* Remap the page. */ struct page *page = skb_shinfo(skb)->frags[0].page; unsigned long pfn = page_to_pfn(page); void *vaddr = page_address(page); MULTI_update_va_mapping(mcl, (unsigned long)vaddr, mfn_pte(mfn, PAGE_KERNEL), 0); mcl++; mmu->ptr = ((u64)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE; mmu->val = pfn; mmu++; set_phys_to_machine(pfn, mfn); } __skb_queue_tail(&free_list, skb); xfer++; } dev_info(&np->netdev->dev, "%s: %d xfer, %d noxfer, %d unused\n", __func__, xfer, noxfer, unused); if (xfer) { if (!xen_feature(XENFEAT_auto_translated_physmap)) { /* Do all the remapping work and M2P updates. */ MULTI_mmu_update(mcl, np->rx_mmu, mmu - np->rx_mmu, NULL, DOMID_SELF); mcl++; HYPERVISOR_multicall(np->rx_mcl, mcl - np->rx_mcl); } } while ((skb = __skb_dequeue(&free_list)) != NULL) dev_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 struct net_device * __devinit 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) { printk(KERN_WARNING "%s> alloc_etherdev failed.\n", __func__); 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; /* Initialise tx_skbs as a free chain containing every entry. */ np->tx_skb_freelist = 0; for (i = 0; i < NET_TX_RING_SIZE; i++) { np->tx_skbs[i].link = i+1; np->grant_tx_ref[i] = GRANT_INVALID_REF; } /* 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) { printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n"); err = -ENOMEM; goto exit; } /* A grant for every rx ring slot */ if (gnttab_alloc_grant_references(RX_MAX_TARGET, &np->gref_rx_head) < 0) { printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n"); err = -ENOMEM; goto exit_free_tx; } netdev->open = xennet_open; netdev->hard_start_xmit = xennet_start_xmit; netdev->stop = xennet_close; netif_napi_add(netdev, &np->napi, xennet_poll, 64); netdev->uninit = xennet_uninit; netdev->change_mtu = xennet_change_mtu; netdev->features = NETIF_F_IP_CSUM; SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops); SET_NETDEV_DEV(netdev, &dev->dev); np->netdev = netdev; netif_carrier_off(netdev); return netdev; exit_free_tx: gnttab_free_grant_references(np->gref_tx_head); 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 __devinit 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->dev.driver_data = info; err = register_netdev(info->netdev); if (err) { printk(KERN_WARNING "%s: register_netdev err=%d\n", __func__, err); goto fail; } err = xennet_sysfs_addif(info->netdev); if (err) { unregister_netdev(info->netdev); printk(KERN_WARNING "%s: add sysfs failed err=%d\n", __func__, err); goto fail; } return 0; fail: free_netdev(netdev); dev->dev.driver_data = 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->netdev->irq) unbind_from_irqhandler(info->netdev->irq, info->netdev); info->evtchn = info->netdev->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->dev.driver_data; 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 irqreturn_t xennet_interrupt(int irq, void *dev_id) { struct net_device *dev = dev_id; struct netfront_info *np = netdev_priv(dev); unsigned long flags; spin_lock_irqsave(&np->tx_lock, flags); if (likely(netif_carrier_ok(dev))) { xennet_tx_buf_gc(dev); /* Under tx_lock: protects access to rx shared-ring indexes. */ if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) netif_rx_schedule(dev, &np->napi); } spin_unlock_irqrestore(&np->tx_lock, flags); return IRQ_HANDLED; } 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; 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 = 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_KERNEL); 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) { free_page((unsigned long)txs); goto fail; } info->tx_ring_ref = err; rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_KERNEL); if (!rxs) { err = -ENOMEM; xenbus_dev_fatal(dev, err, "allocating rx ring page"); goto 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) { free_page((unsigned long)rxs); goto fail; } info->rx_ring_ref = err; err = xenbus_alloc_evtchn(dev, &info->evtchn); if (err) goto fail; err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt, IRQF_SAMPLE_RANDOM, netdev->name, netdev); if (err < 0) goto fail; netdev->irq = err; return 0; fail: return err; } /* Common code used when first setting up, and when resuming. */ static int talk_to_backend(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; } err = xenbus_printf(xbt, dev->nodename, "event-channel", "%u", info->evtchn); if (err) { message = "writing event-channel"; 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_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_set_sg(struct net_device *dev, u32 data) { if (data) { struct netfront_info *np = netdev_priv(dev); int val; if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", "%d", &val) < 0) val = 0; if (!val) return -ENOSYS; } else if (dev->mtu > ETH_DATA_LEN) dev->mtu = ETH_DATA_LEN; return ethtool_op_set_sg(dev, data); } static int xennet_set_tso(struct net_device *dev, u32 data) { if (data) { struct netfront_info *np = netdev_priv(dev); int val; if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-gso-tcpv4", "%d", &val) < 0) val = 0; if (!val) return -ENOSYS; } return ethtool_op_set_tso(dev, data); } static void xennet_set_features(struct net_device *dev) { /* Turn off all GSO bits except ROBUST. */ dev->features &= (1 << NETIF_F_GSO_SHIFT) - 1; dev->features |= NETIF_F_GSO_ROBUST; xennet_set_sg(dev, 0); /* We need checksum offload to enable scatter/gather and TSO. */ if (!(dev->features & NETIF_F_IP_CSUM)) return; if (!xennet_set_sg(dev, 1)) xennet_set_tso(dev, 1); } 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_backend(np->xbdev, np); if (err) return err; xennet_set_features(dev); 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++) { 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); gnttab_grant_foreign_access_ref( ref, np->xbdev->otherend_id, pfn_to_mfn(page_to_pfn(skb_shinfo(skb)-> frags->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->netdev->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 backend_changed(struct xenbus_device *dev, enum xenbus_state backend_state) { struct netfront_info *np = dev->dev.driver_data; struct net_device *netdev = np->netdev; dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); switch (backend_state) { case XenbusStateInitialising: case XenbusStateInitialised: case XenbusStateConnected: case XenbusStateUnknown: case XenbusStateClosed: break; case XenbusStateInitWait: if (dev->state != XenbusStateInitialising) break; if (xennet_connect(netdev) != 0) break; xenbus_switch_state(dev, XenbusStateConnected); break; case XenbusStateClosing: xenbus_frontend_closed(dev); break; } } static struct ethtool_ops xennet_ethtool_ops = { .set_tx_csum = ethtool_op_set_tx_csum, .set_sg = xennet_set_sg, .set_tso = xennet_set_tso, .get_link = ethtool_op_get_link, }; #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 struct xenbus_device_id netfront_ids[] = { { "vif" }, { "" } }; static int __devexit xennet_remove(struct xenbus_device *dev) { struct netfront_info *info = dev->dev.driver_data; dev_dbg(&dev->dev, "%s\n", dev->nodename); unregister_netdev(info->netdev); xennet_disconnect_backend(info); del_timer_sync(&info->rx_refill_timer); xennet_sysfs_delif(info->netdev); free_netdev(info->netdev); return 0; } static struct xenbus_driver netfront = { .name = "vif", .owner = THIS_MODULE, .ids = netfront_ids, .probe = netfront_probe, .remove = __devexit_p(xennet_remove), .resume = netfront_resume, .otherend_changed = backend_changed, }; static int __init netif_init(void) { if (!is_running_on_xen()) return -ENODEV; if (is_initial_xendomain()) return 0; printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n"); return xenbus_register_frontend(&netfront); } module_init(netif_init); static void __exit netif_exit(void) { if (is_initial_xendomain()) return; return xenbus_unregister_driver(&netfront); } module_exit(netif_exit); MODULE_DESCRIPTION("Xen virtual network device frontend"); MODULE_LICENSE("GPL");