virtio_net.c 26.2 KB
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/* A simple 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>
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#include <linux/ethtool.h>
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#include <linux/module.h>
#include <linux/virtio.h>
#include <linux/virtio_net.h>
#include <linux/scatterlist.h>
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#include <linux/if_vlan.h>
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static int napi_weight = 128;
module_param(napi_weight, int, 0444);

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static int csum = 1, gso = 1;
module_param(csum, bool, 0444);
module_param(gso, bool, 0444);

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/* FIXME: MTU in config. */
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#define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
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#define GOOD_COPY_LEN	128
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#define VIRTNET_SEND_COMMAND_SG_MAX    2
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struct virtnet_info
{
	struct virtio_device *vdev;
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	struct virtqueue *rvq, *svq, *cvq;
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	struct net_device *dev;
	struct napi_struct napi;
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	unsigned int status;
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	/* The skb we couldn't send because buffers were full. */
	struct sk_buff *last_xmit_skb;

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	/* If we need to free in a timer, this is it. */
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	struct timer_list xmit_free_timer;

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	/* Number of input buffers, and max we've ever had. */
	unsigned int num, max;

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	/* For cleaning up after transmission. */
	struct tasklet_struct tasklet;
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	bool free_in_tasklet;
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	/* I like... big packets and I cannot lie! */
	bool big_packets;

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	/* Host will merge rx buffers for big packets (shake it! shake it!) */
	bool mergeable_rx_bufs;

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	/* Receive & send queues. */
	struct sk_buff_head recv;
	struct sk_buff_head send;
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	/* Chain pages by the private ptr. */
	struct page *pages;
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};

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static inline void *skb_vnet_hdr(struct sk_buff *skb)
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{
	return (struct virtio_net_hdr *)skb->cb;
}

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static void give_a_page(struct virtnet_info *vi, struct page *page)
{
	page->private = (unsigned long)vi->pages;
	vi->pages = page;
}

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static void trim_pages(struct virtnet_info *vi, struct sk_buff *skb)
{
	unsigned int i;

	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
		give_a_page(vi, skb_shinfo(skb)->frags[i].page);
	skb_shinfo(skb)->nr_frags = 0;
	skb->data_len = 0;
}

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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;
	else
		p = alloc_page(gfp_mask);
	return p;
}

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static void skb_xmit_done(struct virtqueue *svq)
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{
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	struct virtnet_info *vi = svq->vdev->priv;
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	/* Suppress further interrupts. */
	svq->vq_ops->disable_cb(svq);
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	/* We were probably waiting for more output buffers. */
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	netif_wake_queue(vi->dev);
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	/* Make sure we re-xmit last_xmit_skb: if there are no more packets
	 * queued, start_xmit won't be called. */
	tasklet_schedule(&vi->tasklet);
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}

static void receive_skb(struct net_device *dev, struct sk_buff *skb,
			unsigned len)
{
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	struct virtnet_info *vi = netdev_priv(dev);
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	struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
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	int err;
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	int i;
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	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++;
		goto drop;
	}
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	if (vi->mergeable_rx_bufs) {
		struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
		unsigned int copy;
		char *p = page_address(skb_shinfo(skb)->frags[0].page);
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		if (len > PAGE_SIZE)
			len = PAGE_SIZE;
		len -= sizeof(struct virtio_net_hdr_mrg_rxbuf);

		memcpy(hdr, p, sizeof(*mhdr));
		p += sizeof(*mhdr);

		copy = len;
		if (copy > skb_tailroom(skb))
			copy = skb_tailroom(skb);

		memcpy(skb_put(skb, copy), p, copy);

		len -= copy;

		if (!len) {
			give_a_page(vi, skb_shinfo(skb)->frags[0].page);
			skb_shinfo(skb)->nr_frags--;
		} else {
			skb_shinfo(skb)->frags[0].page_offset +=
				sizeof(*mhdr) + copy;
			skb_shinfo(skb)->frags[0].size = len;
			skb->data_len += len;
			skb->len += len;
		}

		while (--mhdr->num_buffers) {
			struct sk_buff *nskb;

			i = skb_shinfo(skb)->nr_frags;
			if (i >= MAX_SKB_FRAGS) {
				pr_debug("%s: packet too long %d\n", dev->name,
					 len);
				dev->stats.rx_length_errors++;
				goto drop;
			}

			nskb = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
			if (!nskb) {
				pr_debug("%s: rx error: %d buffers missing\n",
					 dev->name, mhdr->num_buffers);
				dev->stats.rx_length_errors++;
				goto drop;
			}

			__skb_unlink(nskb, &vi->recv);
			vi->num--;

			skb_shinfo(skb)->frags[i] = skb_shinfo(nskb)->frags[0];
			skb_shinfo(nskb)->nr_frags = 0;
			kfree_skb(nskb);

			if (len > PAGE_SIZE)
				len = PAGE_SIZE;

			skb_shinfo(skb)->frags[i].size = len;
			skb_shinfo(skb)->nr_frags++;
			skb->data_len += len;
			skb->len += len;
		}
	} else {
		len -= sizeof(struct virtio_net_hdr);

		if (len <= MAX_PACKET_LEN)
			trim_pages(vi, skb);

		err = pskb_trim(skb, len);
		if (err) {
			pr_debug("%s: pskb_trim failed %i %d\n", dev->name,
				 len, err);
			dev->stats.rx_dropped++;
			goto drop;
		}
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	}
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	skb->truesize += skb->data_len;
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	dev->stats.rx_bytes += skb->len;
	dev->stats.rx_packets++;

	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
		pr_debug("Needs csum!\n");
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		if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
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			goto frame_err;
	}

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	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);

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	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
		pr_debug("GSO!\n");
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		switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
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		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->gso_type);
			goto frame_err;
		}

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		if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
			skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;

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		skb_shinfo(skb)->gso_size = 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++;
drop:
	dev_kfree_skb(skb);
}

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static void try_fill_recv_maxbufs(struct virtnet_info *vi)
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{
	struct sk_buff *skb;
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	struct scatterlist sg[2+MAX_SKB_FRAGS];
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	int num, err, i;
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	sg_init_table(sg, 2+MAX_SKB_FRAGS);
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	for (;;) {
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		struct virtio_net_hdr *hdr;

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		skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
		if (unlikely(!skb))
			break;

		skb_put(skb, MAX_PACKET_LEN);
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		hdr = skb_vnet_hdr(skb);
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		sg_set_buf(sg, hdr, sizeof(*hdr));
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		if (vi->big_packets) {
			for (i = 0; i < MAX_SKB_FRAGS; i++) {
				skb_frag_t *f = &skb_shinfo(skb)->frags[i];
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				f->page = get_a_page(vi, GFP_ATOMIC);
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				if (!f->page)
					break;

				f->page_offset = 0;
				f->size = PAGE_SIZE;

				skb->data_len += PAGE_SIZE;
				skb->len += PAGE_SIZE;

				skb_shinfo(skb)->nr_frags++;
			}
		}

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		num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
		skb_queue_head(&vi->recv, skb);

		err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
		if (err) {
			skb_unlink(skb, &vi->recv);
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			trim_pages(vi, skb);
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			kfree_skb(skb);
			break;
		}
		vi->num++;
	}
	if (unlikely(vi->num > vi->max))
		vi->max = vi->num;
	vi->rvq->vq_ops->kick(vi->rvq);
}

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static void try_fill_recv(struct virtnet_info *vi)
{
	struct sk_buff *skb;
	struct scatterlist sg[1];
	int err;

	if (!vi->mergeable_rx_bufs) {
		try_fill_recv_maxbufs(vi);
		return;
	}

	for (;;) {
		skb_frag_t *f;

		skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN);
		if (unlikely(!skb))
			break;

		skb_reserve(skb, NET_IP_ALIGN);

		f = &skb_shinfo(skb)->frags[0];
		f->page = get_a_page(vi, GFP_ATOMIC);
		if (!f->page) {
			kfree_skb(skb);
			break;
		}

		f->page_offset = 0;
		f->size = PAGE_SIZE;

		skb_shinfo(skb)->nr_frags++;

		sg_init_one(sg, page_address(f->page), PAGE_SIZE);
		skb_queue_head(&vi->recv, skb);

		err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, skb);
		if (err) {
			skb_unlink(skb, &vi->recv);
			kfree_skb(skb);
			break;
		}
		vi->num++;
	}
	if (unlikely(vi->num > vi->max))
		vi->max = vi->num;
	vi->rvq->vq_ops->kick(vi->rvq);
}

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static void skb_recv_done(struct virtqueue *rvq)
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{
	struct virtnet_info *vi = rvq->vdev->priv;
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	/* Schedule NAPI, Suppress further interrupts if successful. */
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	if (napi_schedule_prep(&vi->napi)) {
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		rvq->vq_ops->disable_cb(rvq);
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		__napi_schedule(&vi->napi);
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	}
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}

static int virtnet_poll(struct napi_struct *napi, int budget)
{
	struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
	struct sk_buff *skb = NULL;
	unsigned int len, received = 0;

again:
	while (received < budget &&
	       (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
		__skb_unlink(skb, &vi->recv);
		receive_skb(vi->dev, skb, len);
		vi->num--;
		received++;
	}

	/* FIXME: If we oom and completely run out of inbufs, we need
	 * to start a timer trying to fill more. */
	if (vi->num < vi->max / 2)
		try_fill_recv(vi);

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	/* Out of packets? */
	if (received < budget) {
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		napi_complete(napi);
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		if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
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		    && napi_schedule_prep(napi)) {
			vi->rvq->vq_ops->disable_cb(vi->rvq);
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			__napi_schedule(napi);
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			goto again;
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		}
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	}

	return received;
}

static void free_old_xmit_skbs(struct virtnet_info *vi)
{
	struct sk_buff *skb;
	unsigned int len;

	while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
		pr_debug("Sent skb %p\n", skb);
		__skb_unlink(skb, &vi->send);
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		vi->dev->stats.tx_bytes += skb->len;
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		vi->dev->stats.tx_packets++;
		kfree_skb(skb);
	}
}

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/* If the virtio transport doesn't always notify us when all in-flight packets
 * are consumed, we fall back to using this function on a timer to free them. */
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static void xmit_free(unsigned long data)
{
	struct virtnet_info *vi = (void *)data;

	netif_tx_lock(vi->dev);

	free_old_xmit_skbs(vi);

	if (!skb_queue_empty(&vi->send))
		mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));

	netif_tx_unlock(vi->dev);
}

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static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
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{
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	int num, err;
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	struct scatterlist sg[2+MAX_SKB_FRAGS];
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	struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
	struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
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	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;

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	sg_init_table(sg, 2+MAX_SKB_FRAGS);
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	pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
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	if (skb->ip_summed == CHECKSUM_PARTIAL) {
		hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
		hdr->csum_start = skb->csum_start - skb_headroom(skb);
		hdr->csum_offset = skb->csum_offset;
	} else {
		hdr->flags = 0;
		hdr->csum_offset = hdr->csum_start = 0;
	}

	if (skb_is_gso(skb)) {
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		hdr->hdr_len = skb_transport_header(skb) - skb->data;
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		hdr->gso_size = skb_shinfo(skb)->gso_size;
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		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
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			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
		else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
		else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
			hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
		else
			BUG();
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		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
			hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
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	} else {
		hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
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		hdr->gso_size = hdr->hdr_len = 0;
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	}

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	mhdr->num_buffers = 0;

	/* Encode metadata header at front. */
	if (vi->mergeable_rx_bufs)
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		sg_set_buf(sg, mhdr, sizeof(*mhdr));
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	else
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		sg_set_buf(sg, hdr, sizeof(*hdr));
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	num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
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	err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
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	if (!err && !vi->free_in_tasklet)
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		mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));

	return err;
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}

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static void xmit_tasklet(unsigned long data)
{
	struct virtnet_info *vi = (void *)data;

	netif_tx_lock_bh(vi->dev);
	if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
		vi->svq->vq_ops->kick(vi->svq);
		vi->last_xmit_skb = NULL;
	}
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	if (vi->free_in_tasklet)
		free_old_xmit_skbs(vi);
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	netif_tx_unlock_bh(vi->dev);
}

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static int start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);
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again:
	/* Free up any pending old buffers before queueing new ones. */
	free_old_xmit_skbs(vi);
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	/* If we has a buffer left over from last time, send it now. */
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	if (unlikely(vi->last_xmit_skb) &&
	    xmit_skb(vi, vi->last_xmit_skb) != 0)
		goto stop_queue;

	vi->last_xmit_skb = NULL;
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	/* Put new one in send queue and do transmit */
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	if (likely(skb)) {
		__skb_queue_head(&vi->send, skb);
		if (xmit_skb(vi, skb) != 0) {
			vi->last_xmit_skb = skb;
			skb = NULL;
			goto stop_queue;
		}
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	}
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done:
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	vi->svq->vq_ops->kick(vi->svq);
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	return NETDEV_TX_OK;

stop_queue:
	pr_debug("%s: virtio not prepared to send\n", dev->name);
	netif_stop_queue(dev);

	/* Activate callback for using skbs: if this returns false it
	 * means some were used in the meantime. */
	if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
		vi->svq->vq_ops->disable_cb(vi->svq);
		netif_start_queue(dev);
		goto again;
	}
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	if (skb) {
		/* Drop this skb: we only queue one. */
		vi->dev->stats.tx_dropped++;
		kfree_skb(skb);
	}
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	goto done;
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}

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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;

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	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);
581 582 583 584

	return 0;
}

585 586 587 588 589 590 591 592 593
#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

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static int virtnet_open(struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);

	napi_enable(&vi->napi);
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	/* If all buffers were filled by other side before we napi_enabled, we
	 * won't get another interrupt, so process any outstanding packets
602 603
	 * now.  virtnet_poll wants re-enable the queue, so we disable here.
	 * We synchronize against interrupts via NAPI_STATE_SCHED */
604
	if (napi_schedule_prep(&vi->napi)) {
605
		vi->rvq->vq_ops->disable_cb(vi->rvq);
606
		__napi_schedule(&vi->napi);
607
	}
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	return 0;
}

611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657
/*
 * 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 sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
	struct virtio_net_ctrl_hdr ctrl;
	virtio_net_ctrl_ack status = ~0;
	unsigned int tmp;

	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
		BUG();  /* Caller should know better */
		return false;
	}

	BUG_ON(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));
	memcpy(&sg[1], data, sizeof(struct scatterlist) * (out + in - 2));
	sg_set_buf(&sg[out + in - 1], &status, sizeof(status));

	if (vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) != 0)
		BUG();

	vi->cvq->vq_ops->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 (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
		cpu_relax();

	return status == VIRTIO_NET_OK;
}

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static int virtnet_close(struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);

	napi_disable(&vi->napi);

	return 0;
}

667 668 669 670 671 672 673 674 675 676 677
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);
}

678 679 680
static void virtnet_set_rx_mode(struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);
681
	struct scatterlist sg[2];
682
	u8 promisc, allmulti;
683 684 685 686
	struct virtio_net_ctrl_mac *mac_data;
	struct dev_addr_list *addr;
	void *buf;
	int i;
687 688 689 690 691

	/* We can't dynamicaly set ndo_set_rx_mode, so return gracefully */
	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
		return;

692 693
	promisc = ((dev->flags & IFF_PROMISC) != 0);
	allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
694

695
	sg_set_buf(sg, &promisc, sizeof(promisc));
696 697 698

	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
				  VIRTIO_NET_CTRL_RX_PROMISC,
699
				  sg, 1, 0))
700 701 702
		dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
			 promisc ? "en" : "dis");

703
	sg_set_buf(sg, &allmulti, sizeof(allmulti));
704 705 706

	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
				  VIRTIO_NET_CTRL_RX_ALLMULTI,
707
				  sg, 1, 0))
708 709
		dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
			 allmulti ? "en" : "dis");
710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744

	/* MAC filter - use one buffer for both lists */
	mac_data = buf = kzalloc(((dev->uc_count + dev->mc_count) * ETH_ALEN) +
				 (2 * sizeof(mac_data->entries)), GFP_ATOMIC);
	if (!buf) {
		dev_warn(&dev->dev, "No memory for MAC address buffer\n");
		return;
	}

	/* Store the unicast list and count in the front of the buffer */
	mac_data->entries = dev->uc_count;
	addr = dev->uc_list;
	for (i = 0; i < dev->uc_count; i++, addr = addr->next)
		memcpy(&mac_data->macs[i][0], addr->da_addr, ETH_ALEN);

	sg_set_buf(&sg[0], mac_data,
		   sizeof(mac_data->entries) + (dev->uc_count * ETH_ALEN));

	/* multicast list and count fill the end */
	mac_data = (void *)&mac_data->macs[dev->uc_count][0];

	mac_data->entries = dev->mc_count;
	addr = dev->mc_list;
	for (i = 0; i < dev->mc_count; i++, addr = addr->next)
		memcpy(&mac_data->macs[i][0], addr->da_addr, ETH_ALEN);

	sg_set_buf(&sg[1], mac_data,
		   sizeof(mac_data->entries) + (dev->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);
745 746
}

747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770
static void virnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
{
	struct virtnet_info *vi = netdev_priv(dev);
	struct scatterlist sg;

	sg_set_buf(&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 virnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
{
	struct virtnet_info *vi = netdev_priv(dev);
	struct scatterlist sg;

	sg_set_buf(&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);
}

771 772 773
static struct ethtool_ops virtnet_ethtool_ops = {
	.set_tx_csum = virtnet_set_tx_csum,
	.set_sg = ethtool_op_set_sg,
774
	.set_tso = ethtool_op_set_tso,
775
	.get_link = ethtool_op_get_link,
776 777
};

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#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;
}

789 790 791 792 793
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,
794
	.ndo_set_mac_address = virtnet_set_mac_address,
795
	.ndo_set_rx_mode     = virtnet_set_rx_mode,
796
	.ndo_change_mtu	     = virtnet_change_mtu,
797 798
	.ndo_vlan_rx_add_vid = virnet_vlan_rx_add_vid,
	.ndo_vlan_rx_kill_vid = virnet_vlan_rx_kill_vid,
799 800 801 802 803
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller = virtnet_netpoll,
#endif
};

804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838
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);
}

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static int virtnet_probe(struct virtio_device *vdev)
{
	int err;
	struct net_device *dev;
	struct virtnet_info *vi;

	/* 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. */
851
	dev->netdev_ops = &virtnet_netdev;
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	dev->features = NETIF_F_HIGHDMA;
853
	SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
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	SET_NETDEV_DEV(dev, &vdev->dev);

	/* Do we support "hardware" checksums? */
857
	if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
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		/* This opens up the world of extra features. */
		dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
860
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
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			dev->features |= NETIF_F_TSO | NETIF_F_UFO
				| NETIF_F_TSO_ECN | NETIF_F_TSO6;
		}
864
		/* Individual feature bits: what can host handle? */
865
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
866
			dev->features |= NETIF_F_TSO;
867
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
868
			dev->features |= NETIF_F_TSO6;
869
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
870
			dev->features |= NETIF_F_TSO_ECN;
871
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
872
			dev->features |= NETIF_F_UFO;
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	}

	/* Configuration may specify what MAC to use.  Otherwise random. */
876
	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
877 878 879
		vdev->config->get(vdev,
				  offsetof(struct virtio_net_config, mac),
				  dev->dev_addr, dev->addr_len);
880
	} else
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		random_ether_addr(dev->dev_addr);

	/* Set up our device-specific information */
	vi = netdev_priv(dev);
885
	netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
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	vi->dev = dev;
	vi->vdev = vdev;
888
	vdev->priv = vi;
889
	vi->pages = NULL;
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891 892 893 894
	/* If they give us a callback when all buffers are done, we don't need
	 * the timer. */
	vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);

895 896 897 898 899 900
	/* 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;

901 902 903
	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
		vi->mergeable_rx_bufs = true;

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	/* We expect two virtqueues, receive then send. */
905
	vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
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	if (IS_ERR(vi->rvq)) {
		err = PTR_ERR(vi->rvq);
		goto free;
	}

911
	vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done);
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	if (IS_ERR(vi->svq)) {
		err = PTR_ERR(vi->svq);
		goto free_recv;
	}

917 918 919 920 921 922
	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
		vi->cvq = vdev->config->find_vq(vdev, 2, NULL);
		if (IS_ERR(vi->cvq)) {
			err = PTR_ERR(vi->svq);
			goto free_send;
		}
923 924 925

		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
			dev->features |= NETIF_F_HW_VLAN_FILTER;
926 927
	}

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	/* Initialize our empty receive and send queues. */
	skb_queue_head_init(&vi->recv);
	skb_queue_head_init(&vi->send);

932 933
	tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);

934 935
	if (!vi->free_in_tasklet)
		setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);
936

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	err = register_netdev(dev);
	if (err) {
		pr_debug("virtio_net: registering device failed\n");
940
		goto free_ctrl;
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	}
942 943 944 945 946 947 948 949 950 951

	/* Last of all, set up some receive buffers. */
	try_fill_recv(vi);

	/* If we didn't even get one input buffer, we're useless. */
	if (vi->num == 0) {
		err = -ENOMEM;
		goto unregister;
	}

952 953
	vi->status = VIRTIO_NET_S_LINK_UP;
	virtnet_update_status(vi);
954
	netif_carrier_on(dev);
955

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	pr_debug("virtnet: registered device %s\n", dev->name);
	return 0;

959 960
unregister:
	unregister_netdev(dev);
961 962 963
free_ctrl:
	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ))
		vdev->config->del_vq(vi->cvq);
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free_send:
	vdev->config->del_vq(vi->svq);
free_recv:
	vdev->config->del_vq(vi->rvq);
free:
	free_netdev(dev);
	return err;
}

static void virtnet_remove(struct virtio_device *vdev)
{
975
	struct virtnet_info *vi = vdev->priv;
976 977
	struct sk_buff *skb;

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	/* Stop all the virtqueues. */
	vdev->config->reset(vdev);

981 982
	if (!vi->free_in_tasklet)
		del_timer_sync(&vi->xmit_free_timer);
983

984 985 986 987 988
	/* Free our skbs in send and recv queues, if any. */
	while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
		kfree_skb(skb);
		vi->num--;
	}
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	__skb_queue_purge(&vi->send);
990 991

	BUG_ON(vi->num != 0);
992 993 994

	vdev->config->del_vq(vi->svq);
	vdev->config->del_vq(vi->rvq);
995 996
	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ))
		vdev->config->del_vq(vi->cvq);
997
	unregister_netdev(vi->dev);
998 999 1000 1001

	while (vi->pages)
		__free_pages(get_a_page(vi, GFP_KERNEL), 0);

1002
	free_netdev(vi->dev);
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}

static struct virtio_device_id id_table[] = {
	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
	{ 0 },
};

1010
static unsigned int features[] = {
1011 1012
	VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
	VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
1013
	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
1014 1015
	VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
	VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */
1016
	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
1017
	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
1018
	VIRTIO_F_NOTIFY_ON_EMPTY,
1019 1020
};

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static struct virtio_driver virtio_net = {
1022 1023
	.feature_table = features,
	.feature_table_size = ARRAY_SIZE(features),
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	.driver.name =	KBUILD_MODNAME,
	.driver.owner =	THIS_MODULE,
	.id_table =	id_table,
	.probe =	virtnet_probe,
	.remove =	__devexit_p(virtnet_remove),
1029
	.config_changed = virtnet_config_changed,
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};

static int __init init(void)
{
	return register_virtio_driver(&virtio_net);
}

static void __exit fini(void)
{
	unregister_virtio_driver(&virtio_net);
}
module_init(init);
module_exit(fini);

MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION("Virtio network driver");
MODULE_LICENSE("GPL");