/* A network driver using virtio. * * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ //#define DEBUG #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/ethtool.h> #include <linux/module.h> #include <linux/virtio.h> #include <linux/virtio_net.h> #include <linux/scatterlist.h> #include <linux/if_vlan.h> #include <linux/slab.h> static int napi_weight = 128; module_param(napi_weight, int, 0444); static int csum = 1, gso = 1; module_param(csum, bool, 0444); module_param(gso, bool, 0444); /* FIXME: MTU in config. */ #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) #define GOOD_COPY_LEN 128 #define VIRTNET_SEND_COMMAND_SG_MAX 2 struct virtnet_info { struct virtio_device *vdev; struct virtqueue *rvq, *svq, *cvq; struct net_device *dev; struct napi_struct napi; unsigned int status; /* Number of input buffers, and max we've ever had. */ unsigned int num, max; /* I like... big packets and I cannot lie! */ bool big_packets; /* Host will merge rx buffers for big packets (shake it! shake it!) */ bool mergeable_rx_bufs; /* Work struct for refilling if we run low on memory. */ struct delayed_work refill; /* Chain pages by the private ptr. */ struct page *pages; /* fragments + linear part + virtio header */ struct scatterlist rx_sg[MAX_SKB_FRAGS + 2]; struct scatterlist tx_sg[MAX_SKB_FRAGS + 2]; }; struct skb_vnet_hdr { union { struct virtio_net_hdr hdr; struct virtio_net_hdr_mrg_rxbuf mhdr; }; unsigned int num_sg; }; struct padded_vnet_hdr { struct virtio_net_hdr hdr; /* * virtio_net_hdr should be in a separated sg buffer because of a * QEMU bug, and data sg buffer shares same page with this header sg. * This padding makes next sg 16 byte aligned after virtio_net_hdr. */ char padding[6]; }; static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb) { return (struct skb_vnet_hdr *)skb->cb; } /* * private is used to chain pages for big packets, put the whole * most recent used list in the beginning for reuse */ static void give_pages(struct virtnet_info *vi, struct page *page) { struct page *end; /* Find end of list, sew whole thing into vi->pages. */ for (end = page; end->private; end = (struct page *)end->private); end->private = (unsigned long)vi->pages; vi->pages = page; } static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask) { struct page *p = vi->pages; if (p) { vi->pages = (struct page *)p->private; /* clear private here, it is used to chain pages */ p->private = 0; } else p = alloc_page(gfp_mask); return p; } static void skb_xmit_done(struct virtqueue *svq) { struct virtnet_info *vi = svq->vdev->priv; /* Suppress further interrupts. */ virtqueue_disable_cb(svq); /* We were probably waiting for more output buffers. */ netif_wake_queue(vi->dev); } static void set_skb_frag(struct sk_buff *skb, struct page *page, unsigned int offset, unsigned int *len) { int i = skb_shinfo(skb)->nr_frags; skb_frag_t *f; f = &skb_shinfo(skb)->frags[i]; f->size = min((unsigned)PAGE_SIZE - offset, *len); f->page_offset = offset; f->page = page; skb->data_len += f->size; skb->len += f->size; skb_shinfo(skb)->nr_frags++; *len -= f->size; } static struct sk_buff *page_to_skb(struct virtnet_info *vi, struct page *page, unsigned int len) { struct sk_buff *skb; struct skb_vnet_hdr *hdr; unsigned int copy, hdr_len, offset; char *p; p = page_address(page); /* copy small packet so we can reuse these pages for small data */ skb = netdev_alloc_skb_ip_align(vi->dev, GOOD_COPY_LEN); if (unlikely(!skb)) return NULL; hdr = skb_vnet_hdr(skb); if (vi->mergeable_rx_bufs) { hdr_len = sizeof hdr->mhdr; offset = hdr_len; } else { hdr_len = sizeof hdr->hdr; offset = sizeof(struct padded_vnet_hdr); } memcpy(hdr, p, hdr_len); len -= hdr_len; p += offset; copy = len; if (copy > skb_tailroom(skb)) copy = skb_tailroom(skb); memcpy(skb_put(skb, copy), p, copy); len -= copy; offset += copy; while (len) { set_skb_frag(skb, page, offset, &len); page = (struct page *)page->private; offset = 0; } if (page) give_pages(vi, page); return skb; } static int receive_mergeable(struct virtnet_info *vi, struct sk_buff *skb) { struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); struct page *page; int num_buf, i, len; num_buf = hdr->mhdr.num_buffers; while (--num_buf) { i = skb_shinfo(skb)->nr_frags; if (i >= MAX_SKB_FRAGS) { pr_debug("%s: packet too long\n", skb->dev->name); skb->dev->stats.rx_length_errors++; return -EINVAL; } page = virtqueue_get_buf(vi->rvq, &len); if (!page) { pr_debug("%s: rx error: %d buffers missing\n", skb->dev->name, hdr->mhdr.num_buffers); skb->dev->stats.rx_length_errors++; return -EINVAL; } if (len > PAGE_SIZE) len = PAGE_SIZE; set_skb_frag(skb, page, 0, &len); --vi->num; } return 0; } static void receive_buf(struct net_device *dev, void *buf, unsigned int len) { struct virtnet_info *vi = netdev_priv(dev); struct sk_buff *skb; struct page *page; struct skb_vnet_hdr *hdr; if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) { pr_debug("%s: short packet %i\n", dev->name, len); dev->stats.rx_length_errors++; if (vi->mergeable_rx_bufs || vi->big_packets) give_pages(vi, buf); else dev_kfree_skb(buf); return; } if (!vi->mergeable_rx_bufs && !vi->big_packets) { skb = buf; len -= sizeof(struct virtio_net_hdr); skb_trim(skb, len); } else { page = buf; skb = page_to_skb(vi, page, len); if (unlikely(!skb)) { dev->stats.rx_dropped++; give_pages(vi, page); return; } if (vi->mergeable_rx_bufs) if (receive_mergeable(vi, skb)) { dev_kfree_skb(skb); return; } } hdr = skb_vnet_hdr(skb); skb->truesize += skb->data_len; dev->stats.rx_bytes += skb->len; dev->stats.rx_packets++; if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { pr_debug("Needs csum!\n"); if (!skb_partial_csum_set(skb, hdr->hdr.csum_start, hdr->hdr.csum_offset)) goto frame_err; } skb->protocol = eth_type_trans(skb, dev); pr_debug("Receiving skb proto 0x%04x len %i type %i\n", ntohs(skb->protocol), skb->len, skb->pkt_type); if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) { pr_debug("GSO!\n"); switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { case VIRTIO_NET_HDR_GSO_TCPV4: skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; break; case VIRTIO_NET_HDR_GSO_UDP: skb_shinfo(skb)->gso_type = SKB_GSO_UDP; break; case VIRTIO_NET_HDR_GSO_TCPV6: skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; break; default: if (net_ratelimit()) printk(KERN_WARNING "%s: bad gso type %u.\n", dev->name, hdr->hdr.gso_type); goto frame_err; } if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN) skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; skb_shinfo(skb)->gso_size = hdr->hdr.gso_size; if (skb_shinfo(skb)->gso_size == 0) { if (net_ratelimit()) printk(KERN_WARNING "%s: zero gso size.\n", dev->name); goto frame_err; } /* Header must be checked, and gso_segs computed. */ skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; skb_shinfo(skb)->gso_segs = 0; } netif_receive_skb(skb); return; frame_err: dev->stats.rx_frame_errors++; dev_kfree_skb(skb); } static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp) { struct sk_buff *skb; struct skb_vnet_hdr *hdr; int err; skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN); if (unlikely(!skb)) return -ENOMEM; skb_put(skb, MAX_PACKET_LEN); hdr = skb_vnet_hdr(skb); sg_set_buf(vi->rx_sg, &hdr->hdr, sizeof hdr->hdr); skb_to_sgvec(skb, vi->rx_sg + 1, 0, skb->len); err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 2, skb, gfp); if (err < 0) dev_kfree_skb(skb); return err; } static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp) { struct page *first, *list = NULL; char *p; int i, err, offset; /* page in vi->rx_sg[MAX_SKB_FRAGS + 1] is list tail */ for (i = MAX_SKB_FRAGS + 1; i > 1; --i) { first = get_a_page(vi, gfp); if (!first) { if (list) give_pages(vi, list); return -ENOMEM; } sg_set_buf(&vi->rx_sg[i], page_address(first), PAGE_SIZE); /* chain new page in list head to match sg */ first->private = (unsigned long)list; list = first; } first = get_a_page(vi, gfp); if (!first) { give_pages(vi, list); return -ENOMEM; } p = page_address(first); /* vi->rx_sg[0], vi->rx_sg[1] share the same page */ /* a separated vi->rx_sg[0] for virtio_net_hdr only due to QEMU bug */ sg_set_buf(&vi->rx_sg[0], p, sizeof(struct virtio_net_hdr)); /* vi->rx_sg[1] for data packet, from offset */ offset = sizeof(struct padded_vnet_hdr); sg_set_buf(&vi->rx_sg[1], p + offset, PAGE_SIZE - offset); /* chain first in list head */ first->private = (unsigned long)list; err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, MAX_SKB_FRAGS + 2, first, gfp); if (err < 0) give_pages(vi, first); return err; } static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) { struct page *page; int err; page = get_a_page(vi, gfp); if (!page) return -ENOMEM; sg_init_one(vi->rx_sg, page_address(page), PAGE_SIZE); err = virtqueue_add_buf_gfp(vi->rvq, vi->rx_sg, 0, 1, page, gfp); if (err < 0) give_pages(vi, page); return err; } /* Returns false if we couldn't fill entirely (OOM). */ static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) { int err; bool oom = false; do { if (vi->mergeable_rx_bufs) err = add_recvbuf_mergeable(vi, gfp); else if (vi->big_packets) err = add_recvbuf_big(vi, gfp); else err = add_recvbuf_small(vi, gfp); if (err < 0) { oom = true; break; } ++vi->num; } while (err > 0); if (unlikely(vi->num > vi->max)) vi->max = vi->num; virtqueue_kick(vi->rvq); return !oom; } static void skb_recv_done(struct virtqueue *rvq) { struct virtnet_info *vi = rvq->vdev->priv; /* Schedule NAPI, Suppress further interrupts if successful. */ if (napi_schedule_prep(&vi->napi)) { virtqueue_disable_cb(rvq); __napi_schedule(&vi->napi); } } static void refill_work(struct work_struct *work) { struct virtnet_info *vi; bool still_empty; vi = container_of(work, struct virtnet_info, refill.work); napi_disable(&vi->napi); still_empty = !try_fill_recv(vi, GFP_KERNEL); napi_enable(&vi->napi); /* In theory, this can happen: if we don't get any buffers in * we will *never* try to fill again. */ if (still_empty) schedule_delayed_work(&vi->refill, HZ/2); } static int virtnet_poll(struct napi_struct *napi, int budget) { struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi); void *buf; unsigned int len, received = 0; again: while (received < budget && (buf = virtqueue_get_buf(vi->rvq, &len)) != NULL) { receive_buf(vi->dev, buf, len); --vi->num; received++; } if (vi->num < vi->max / 2) { if (!try_fill_recv(vi, GFP_ATOMIC)) schedule_delayed_work(&vi->refill, 0); } /* Out of packets? */ if (received < budget) { napi_complete(napi); if (unlikely(!virtqueue_enable_cb(vi->rvq)) && napi_schedule_prep(napi)) { virtqueue_disable_cb(vi->rvq); __napi_schedule(napi); goto again; } } return received; } static unsigned int free_old_xmit_skbs(struct virtnet_info *vi) { struct sk_buff *skb; unsigned int len, tot_sgs = 0; while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) { pr_debug("Sent skb %p\n", skb); vi->dev->stats.tx_bytes += skb->len; vi->dev->stats.tx_packets++; tot_sgs += skb_vnet_hdr(skb)->num_sg; dev_kfree_skb_any(skb); } return tot_sgs; } static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb) { struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb); const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); if (skb->ip_summed == CHECKSUM_PARTIAL) { hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb); hdr->hdr.csum_offset = skb->csum_offset; } else { hdr->hdr.flags = 0; hdr->hdr.csum_offset = hdr->hdr.csum_start = 0; } if (skb_is_gso(skb)) { hdr->hdr.hdr_len = skb_headlen(skb); hdr->hdr.gso_size = skb_shinfo(skb)->gso_size; if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP; else BUG(); if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN) hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN; } else { hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; hdr->hdr.gso_size = hdr->hdr.hdr_len = 0; } hdr->mhdr.num_buffers = 0; /* Encode metadata header at front. */ if (vi->mergeable_rx_bufs) sg_set_buf(vi->tx_sg, &hdr->mhdr, sizeof hdr->mhdr); else sg_set_buf(vi->tx_sg, &hdr->hdr, sizeof hdr->hdr); hdr->num_sg = skb_to_sgvec(skb, vi->tx_sg + 1, 0, skb->len) + 1; return virtqueue_add_buf(vi->svq, vi->tx_sg, hdr->num_sg, 0, skb); } static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); int capacity; again: /* Free up any pending old buffers before queueing new ones. */ free_old_xmit_skbs(vi); /* Try to transmit */ capacity = xmit_skb(vi, skb); /* This can happen with OOM and indirect buffers. */ if (unlikely(capacity < 0)) { netif_stop_queue(dev); dev_warn(&dev->dev, "Unexpected full queue\n"); if (unlikely(!virtqueue_enable_cb(vi->svq))) { virtqueue_disable_cb(vi->svq); netif_start_queue(dev); goto again; } return NETDEV_TX_BUSY; } virtqueue_kick(vi->svq); /* Don't wait up for transmitted skbs to be freed. */ skb_orphan(skb); nf_reset(skb); /* Apparently nice girls don't return TX_BUSY; stop the queue * before it gets out of hand. Naturally, this wastes entries. */ if (capacity < 2+MAX_SKB_FRAGS) { netif_stop_queue(dev); if (unlikely(!virtqueue_enable_cb(vi->svq))) { /* More just got used, free them then recheck. */ capacity += free_old_xmit_skbs(vi); if (capacity >= 2+MAX_SKB_FRAGS) { netif_start_queue(dev); virtqueue_disable_cb(vi->svq); } } } return NETDEV_TX_OK; } static int virtnet_set_mac_address(struct net_device *dev, void *p) { struct virtnet_info *vi = netdev_priv(dev); struct virtio_device *vdev = vi->vdev; int ret; ret = eth_mac_addr(dev, p); if (ret) return ret; if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) vdev->config->set(vdev, offsetof(struct virtio_net_config, mac), dev->dev_addr, dev->addr_len); return 0; } #ifdef CONFIG_NET_POLL_CONTROLLER static void virtnet_netpoll(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); napi_schedule(&vi->napi); } #endif static int virtnet_open(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); napi_enable(&vi->napi); /* If all buffers were filled by other side before we napi_enabled, we * won't get another interrupt, so process any outstanding packets * now. virtnet_poll wants re-enable the queue, so we disable here. * We synchronize against interrupts via NAPI_STATE_SCHED */ if (napi_schedule_prep(&vi->napi)) { virtqueue_disable_cb(vi->rvq); __napi_schedule(&vi->napi); } return 0; } /* * Send command via the control virtqueue and check status. Commands * supported by the hypervisor, as indicated by feature bits, should * never fail unless improperly formated. */ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, struct scatterlist *data, int out, int in) { struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2]; struct virtio_net_ctrl_hdr ctrl; virtio_net_ctrl_ack status = ~0; unsigned int tmp; int i; /* Caller should know better */ BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) || (out + in > VIRTNET_SEND_COMMAND_SG_MAX)); out++; /* Add header */ in++; /* Add return status */ ctrl.class = class; ctrl.cmd = cmd; sg_init_table(sg, out + in); sg_set_buf(&sg[0], &ctrl, sizeof(ctrl)); for_each_sg(data, s, out + in - 2, i) sg_set_buf(&sg[i + 1], sg_virt(s), s->length); sg_set_buf(&sg[out + in - 1], &status, sizeof(status)); BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi) < 0); virtqueue_kick(vi->cvq); /* * Spin for a response, the kick causes an ioport write, trapping * into the hypervisor, so the request should be handled immediately. */ while (!virtqueue_get_buf(vi->cvq, &tmp)) cpu_relax(); return status == VIRTIO_NET_OK; } static int virtnet_close(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); napi_disable(&vi->napi); return 0; } static int virtnet_set_tx_csum(struct net_device *dev, u32 data) { struct virtnet_info *vi = netdev_priv(dev); struct virtio_device *vdev = vi->vdev; if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) return -ENOSYS; return ethtool_op_set_tx_hw_csum(dev, data); } static void virtnet_set_rx_mode(struct net_device *dev) { struct virtnet_info *vi = netdev_priv(dev); struct scatterlist sg[2]; u8 promisc, allmulti; struct virtio_net_ctrl_mac *mac_data; struct netdev_hw_addr *ha; int uc_count; int mc_count; void *buf; int i; /* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */ if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX)) return; promisc = ((dev->flags & IFF_PROMISC) != 0); allmulti = ((dev->flags & IFF_ALLMULTI) != 0); sg_init_one(sg, &promisc, sizeof(promisc)); if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, VIRTIO_NET_CTRL_RX_PROMISC, sg, 1, 0)) dev_warn(&dev->dev, "Failed to %sable promisc mode.\n", promisc ? "en" : "dis"); sg_init_one(sg, &allmulti, sizeof(allmulti)); if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX, VIRTIO_NET_CTRL_RX_ALLMULTI, sg, 1, 0)) dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n", allmulti ? "en" : "dis"); uc_count = netdev_uc_count(dev); mc_count = netdev_mc_count(dev); /* MAC filter - use one buffer for both lists */ buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) + (2 * sizeof(mac_data->entries)), GFP_ATOMIC); mac_data = buf; if (!buf) { dev_warn(&dev->dev, "No memory for MAC address buffer\n"); return; } sg_init_table(sg, 2); /* Store the unicast list and count in the front of the buffer */ mac_data->entries = uc_count; i = 0; netdev_for_each_uc_addr(ha, dev) memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); sg_set_buf(&sg[0], mac_data, sizeof(mac_data->entries) + (uc_count * ETH_ALEN)); /* multicast list and count fill the end */ mac_data = (void *)&mac_data->macs[uc_count][0]; mac_data->entries = mc_count; i = 0; netdev_for_each_mc_addr(ha, dev) memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN); sg_set_buf(&sg[1], mac_data, sizeof(mac_data->entries) + (mc_count * ETH_ALEN)); if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, VIRTIO_NET_CTRL_MAC_TABLE_SET, sg, 2, 0)) dev_warn(&dev->dev, "Failed to set MAC fitler table.\n"); kfree(buf); } static void virtnet_vlan_rx_add_vid(struct net_device *dev, u16 vid) { struct virtnet_info *vi = netdev_priv(dev); struct scatterlist sg; sg_init_one(&sg, &vid, sizeof(vid)); if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0)) dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid); } static void virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid) { struct virtnet_info *vi = netdev_priv(dev); struct scatterlist sg; sg_init_one(&sg, &vid, sizeof(vid)); if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN, VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0)) dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid); } static const struct ethtool_ops virtnet_ethtool_ops = { .set_tx_csum = virtnet_set_tx_csum, .set_sg = ethtool_op_set_sg, .set_tso = ethtool_op_set_tso, .set_ufo = ethtool_op_set_ufo, .get_link = ethtool_op_get_link, }; #define MIN_MTU 68 #define MAX_MTU 65535 static int virtnet_change_mtu(struct net_device *dev, int new_mtu) { if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) return -EINVAL; dev->mtu = new_mtu; return 0; } static const struct net_device_ops virtnet_netdev = { .ndo_open = virtnet_open, .ndo_stop = virtnet_close, .ndo_start_xmit = start_xmit, .ndo_validate_addr = eth_validate_addr, .ndo_set_mac_address = virtnet_set_mac_address, .ndo_set_rx_mode = virtnet_set_rx_mode, .ndo_change_mtu = virtnet_change_mtu, .ndo_vlan_rx_add_vid = virtnet_vlan_rx_add_vid, .ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid, #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = virtnet_netpoll, #endif }; static void virtnet_update_status(struct virtnet_info *vi) { u16 v; if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) return; vi->vdev->config->get(vi->vdev, offsetof(struct virtio_net_config, status), &v, sizeof(v)); /* Ignore unknown (future) status bits */ v &= VIRTIO_NET_S_LINK_UP; if (vi->status == v) return; vi->status = v; if (vi->status & VIRTIO_NET_S_LINK_UP) { netif_carrier_on(vi->dev); netif_wake_queue(vi->dev); } else { netif_carrier_off(vi->dev); netif_stop_queue(vi->dev); } } static void virtnet_config_changed(struct virtio_device *vdev) { struct virtnet_info *vi = vdev->priv; virtnet_update_status(vi); } static int virtnet_probe(struct virtio_device *vdev) { int err; struct net_device *dev; struct virtnet_info *vi; struct virtqueue *vqs[3]; vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL}; const char *names[] = { "input", "output", "control" }; int nvqs; /* Allocate ourselves a network device with room for our info */ dev = alloc_etherdev(sizeof(struct virtnet_info)); if (!dev) return -ENOMEM; /* Set up network device as normal. */ dev->netdev_ops = &virtnet_netdev; dev->features = NETIF_F_HIGHDMA; SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops); SET_NETDEV_DEV(dev, &vdev->dev); /* Do we support "hardware" checksums? */ if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { /* This opens up the world of extra features. */ dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { dev->features |= NETIF_F_TSO | NETIF_F_UFO | NETIF_F_TSO_ECN | NETIF_F_TSO6; } /* Individual feature bits: what can host handle? */ if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4)) dev->features |= NETIF_F_TSO; if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6)) dev->features |= NETIF_F_TSO6; if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN)) dev->features |= NETIF_F_TSO_ECN; if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO)) dev->features |= NETIF_F_UFO; } /* Configuration may specify what MAC to use. Otherwise random. */ if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { vdev->config->get(vdev, offsetof(struct virtio_net_config, mac), dev->dev_addr, dev->addr_len); } else random_ether_addr(dev->dev_addr); /* Set up our device-specific information */ vi = netdev_priv(dev); netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight); vi->dev = dev; vi->vdev = vdev; vdev->priv = vi; vi->pages = NULL; INIT_DELAYED_WORK(&vi->refill, refill_work); sg_init_table(vi->rx_sg, ARRAY_SIZE(vi->rx_sg)); sg_init_table(vi->tx_sg, ARRAY_SIZE(vi->tx_sg)); /* If we can receive ANY GSO packets, we must allocate large ones. */ if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN)) vi->big_packets = true; if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) vi->mergeable_rx_bufs = true; /* We expect two virtqueues, receive then send, * and optionally control. */ nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2; err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names); if (err) goto free; vi->rvq = vqs[0]; vi->svq = vqs[1]; if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) { vi->cvq = vqs[2]; if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN)) dev->features |= NETIF_F_HW_VLAN_FILTER; } err = register_netdev(dev); if (err) { pr_debug("virtio_net: registering device failed\n"); goto free_vqs; } /* Last of all, set up some receive buffers. */ try_fill_recv(vi, GFP_KERNEL); /* If we didn't even get one input buffer, we're useless. */ if (vi->num == 0) { err = -ENOMEM; goto unregister; } vi->status = VIRTIO_NET_S_LINK_UP; virtnet_update_status(vi); netif_carrier_on(dev); pr_debug("virtnet: registered device %s\n", dev->name); return 0; unregister: unregister_netdev(dev); cancel_delayed_work_sync(&vi->refill); free_vqs: vdev->config->del_vqs(vdev); free: free_netdev(dev); return err; } static void free_unused_bufs(struct virtnet_info *vi) { void *buf; while (1) { buf = virtqueue_detach_unused_buf(vi->svq); if (!buf) break; dev_kfree_skb(buf); } while (1) { buf = virtqueue_detach_unused_buf(vi->rvq); if (!buf) break; if (vi->mergeable_rx_bufs || vi->big_packets) give_pages(vi, buf); else dev_kfree_skb(buf); --vi->num; } BUG_ON(vi->num != 0); } static void __devexit virtnet_remove(struct virtio_device *vdev) { struct virtnet_info *vi = vdev->priv; /* Stop all the virtqueues. */ vdev->config->reset(vdev); unregister_netdev(vi->dev); cancel_delayed_work_sync(&vi->refill); /* Free unused buffers in both send and recv, if any. */ free_unused_bufs(vi); vdev->config->del_vqs(vi->vdev); while (vi->pages) __free_pages(get_a_page(vi, GFP_KERNEL), 0); free_netdev(vi->dev); } static struct virtio_device_id id_table[] = { { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, { 0 }, }; static unsigned int features[] = { VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC, VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, }; static struct virtio_driver virtio_net_driver = { .feature_table = features, .feature_table_size = ARRAY_SIZE(features), .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, .probe = virtnet_probe, .remove = __devexit_p(virtnet_remove), .config_changed = virtnet_config_changed, }; static int __init init(void) { return register_virtio_driver(&virtio_net_driver); } static void __exit fini(void) { unregister_virtio_driver(&virtio_net_driver); } module_init(init); module_exit(fini); MODULE_DEVICE_TABLE(virtio, id_table); MODULE_DESCRIPTION("Virtio network driver"); MODULE_LICENSE("GPL");