Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 1268 insertions, 0 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
new file mode 100644
index 00000000..cbefe671
--- /dev/null
+++ b/drivers/net/virtio_net.c
@@ -0,0 +1,1268 @@
+/* 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 bool csum = true, gso = true;
+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
+#define VIRTNET_DRIVER_VERSION "1.0.0"
+
+struct virtnet_stats {
+	struct u64_stats_sync syncp;
+	u64 tx_bytes;
+	u64 tx_packets;
+
+	u64 rx_bytes;
+	u64 rx_packets;
+};
+
+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;
+
+	/* Active statistics */
+	struct virtnet_stats __percpu *stats;
+
+	/* 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 size = min((unsigned)PAGE_SIZE - offset, *len);
+	int i = skb_shinfo(skb)->nr_frags;
+
+	__skb_fill_page_desc(skb, i, page, offset, size);
+
+	skb->data_len += size;
+	skb->len += size;
+	skb->truesize += PAGE_SIZE;
+	skb_shinfo(skb)->nr_frags++;
+	*len -= size;
+}
+
+/* Called from bottom half context */
+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;
+
+	/*
+	 * Verify that we can indeed put this data into a skb.
+	 * This is here to handle cases when the device erroneously
+	 * tries to receive more than is possible. This is usually
+	 * the case of a broken device.
+	 */
+	if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
+		if (net_ratelimit())
+			pr_debug("%s: too much data\n", skb->dev->name);
+		dev_kfree_skb(skb);
+		return NULL;
+	}
+
+	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 virtnet_stats *stats = this_cpu_ptr(vi->stats);
+	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);
+
+	u64_stats_update_begin(&stats->syncp);
+	stats->rx_bytes += skb->len;
+	stats->rx_packets++;
+	u64_stats_update_end(&stats->syncp);
+
+	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;
+	} else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID) {
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+	}
+
+	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, gfp);
+	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(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(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(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).
+ *
+ * Normally run in the receive path, but can also be run from ndo_open
+ * before we're receiving packets, or from refill_work which is
+ * careful to disable receiving (using napi_disable).
+ */
+static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp)
+{
+	int err;
+	bool oom;
+
+	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);
+
+		oom = err == -ENOMEM;
+		if (err < 0)
+			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 virtnet_napi_enable(struct virtnet_info *vi)
+{
+	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);
+		local_bh_disable();
+		__napi_schedule(&vi->napi);
+		local_bh_enable();
+	}
+}
+
+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);
+	virtnet_napi_enable(vi);
+
+	/* In theory, this can happen: if we don't get any buffers in
+	 * we will *never* try to fill again. */
+	if (still_empty)
+		queue_delayed_work(system_nrt_wq, &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))
+			queue_delayed_work(system_nrt_wq, &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;
+	struct virtnet_stats *stats = this_cpu_ptr(vi->stats);
+
+	while ((skb = virtqueue_get_buf(vi->svq, &len)) != NULL) {
+		pr_debug("Sent skb %p\n", skb);
+
+		u64_stats_update_begin(&stats->syncp);
+		stats->tx_bytes += skb->len;
+		stats->tx_packets++;
+		u64_stats_update_end(&stats->syncp);
+
+		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_checksum_start_offset(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, GFP_ATOMIC);
+}
+
+static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	int capacity;
+
+	/* 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)) {
+		if (likely(capacity == -ENOMEM)) {
+			if (net_ratelimit())
+				dev_warn(&dev->dev,
+					 "TX queue failure: out of memory\n");
+		} else {
+			dev->stats.tx_fifo_errors++;
+			if (net_ratelimit())
+				dev_warn(&dev->dev,
+					 "Unexpected TX queue failure: %d\n",
+					 capacity);
+		}
+		dev->stats.tx_dropped++;
+		kfree_skb(skb);
+		return NETDEV_TX_OK;
+	}
+	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_delayed(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;
+}
+
+static struct rtnl_link_stats64 *virtnet_stats(struct net_device *dev,
+					       struct rtnl_link_stats64 *tot)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	int cpu;
+	unsigned int start;
+
+	for_each_possible_cpu(cpu) {
+		struct virtnet_stats *stats = per_cpu_ptr(vi->stats, cpu);
+		u64 tpackets, tbytes, rpackets, rbytes;
+
+		do {
+			start = u64_stats_fetch_begin(&stats->syncp);
+			tpackets = stats->tx_packets;
+			tbytes   = stats->tx_bytes;
+			rpackets = stats->rx_packets;
+			rbytes   = stats->rx_bytes;
+		} while (u64_stats_fetch_retry(&stats->syncp, start));
+
+		tot->rx_packets += rpackets;
+		tot->tx_packets += tpackets;
+		tot->rx_bytes   += rbytes;
+		tot->tx_bytes   += tbytes;
+	}
+
+	tot->tx_dropped = dev->stats.tx_dropped;
+	tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
+	tot->rx_dropped = dev->stats.rx_dropped;
+	tot->rx_length_errors = dev->stats.rx_length_errors;
+	tot->rx_frame_errors = dev->stats.rx_frame_errors;
+
+	return tot;
+}
+
+#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);
+
+	/* Make sure we have some buffers: if oom use wq. */
+	if (!try_fill_recv(vi, GFP_KERNEL))
+		queue_delayed_work(system_nrt_wq, &vi->refill, 0);
+
+	virtnet_napi_enable(vi);
+	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, GFP_ATOMIC) < 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);
+
+	/* Make sure refill_work doesn't re-enable napi! */
+	cancel_delayed_work_sync(&vi->refill);
+	napi_disable(&vi->napi);
+
+	return 0;
+}
+
+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 int 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);
+	return 0;
+}
+
+static int 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);
+	return 0;
+}
+
+static void virtnet_get_ringparam(struct net_device *dev,
+				struct ethtool_ringparam *ring)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+
+	ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq);
+	ring->tx_max_pending = virtqueue_get_vring_size(vi->svq);
+	ring->rx_pending = ring->rx_max_pending;
+	ring->tx_pending = ring->tx_max_pending;
+
+}
+
+
+static void virtnet_get_drvinfo(struct net_device *dev,
+				struct ethtool_drvinfo *info)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	struct virtio_device *vdev = vi->vdev;
+
+	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
+	strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
+	strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
+
+}
+
+static const struct ethtool_ops virtnet_ethtool_ops = {
+	.get_drvinfo = virtnet_get_drvinfo,
+	.get_link = ethtool_op_get_link,
+	.get_ringparam = virtnet_get_ringparam,
+};
+
+#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_get_stats64     = virtnet_stats,
+	.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_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
+			      offsetof(struct virtio_net_config, status),
+			      &v) < 0)
+		return;
+
+	/* 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 init_vqs(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, err;
+
+	/* We expect two virtqueues, receive then send,
+	 * and optionally control. */
+	nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
+
+	err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks, names);
+	if (err)
+		return err;
+
+	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))
+			vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
+	}
+	return 0;
+}
+
+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. */
+	dev->priv_flags |= IFF_UNICAST_FLT;
+	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 (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
+		/* This opens up the world of extra features. */
+		dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
+		if (csum)
+			dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
+
+		if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
+			dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
+				| NETIF_F_TSO_ECN | NETIF_F_TSO6;
+		}
+		/* Individual feature bits: what can host handle? */
+		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
+			dev->hw_features |= NETIF_F_TSO;
+		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
+			dev->hw_features |= NETIF_F_TSO6;
+		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
+			dev->hw_features |= NETIF_F_TSO_ECN;
+		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
+			dev->hw_features |= NETIF_F_UFO;
+
+		if (gso)
+			dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
+		/* (!csum && gso) case will be fixed by register_netdev() */
+	}
+
+	/* Configuration may specify what MAC to use.  Otherwise random. */
+	if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
+				  offsetof(struct virtio_net_config, mac),
+				  dev->dev_addr, dev->addr_len) < 0)
+		eth_hw_addr_random(dev);
+
+	/* 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;
+	vi->stats = alloc_percpu(struct virtnet_stats);
+	err = -ENOMEM;
+	if (vi->stats == NULL)
+		goto free;
+
+	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;
+
+	err = init_vqs(vi);
+	if (err)
+		goto free_stats;
+
+	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;
+	}
+
+	/* Assume link up if device can't report link status,
+	   otherwise get link status from config. */
+	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
+		netif_carrier_off(dev);
+		virtnet_update_status(vi);
+	} else {
+		vi->status = VIRTIO_NET_S_LINK_UP;
+		netif_carrier_on(dev);
+	}
+
+	pr_debug("virtnet: registered device %s\n", dev->name);
+	return 0;
+
+unregister:
+	unregister_netdev(dev);
+free_vqs:
+	vdev->config->del_vqs(vdev);
+free_stats:
+	free_percpu(vi->stats);
+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 remove_vq_common(struct virtnet_info *vi)
+{
+	vi->vdev->config->reset(vi->vdev);
+
+	/* Free unused buffers in both send and recv, if any. */
+	free_unused_bufs(vi);
+
+	vi->vdev->config->del_vqs(vi->vdev);
+
+	while (vi->pages)
+		__free_pages(get_a_page(vi, GFP_KERNEL), 0);
+}
+
+static void __devexit virtnet_remove(struct virtio_device *vdev)
+{
+	struct virtnet_info *vi = vdev->priv;
+
+	unregister_netdev(vi->dev);
+
+	remove_vq_common(vi);
+
+	free_percpu(vi->stats);
+	free_netdev(vi->dev);
+}
+
+#ifdef CONFIG_PM
+static int virtnet_freeze(struct virtio_device *vdev)
+{
+	struct virtnet_info *vi = vdev->priv;
+
+	virtqueue_disable_cb(vi->rvq);
+	virtqueue_disable_cb(vi->svq);
+	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ))
+		virtqueue_disable_cb(vi->cvq);
+
+	netif_device_detach(vi->dev);
+	cancel_delayed_work_sync(&vi->refill);
+
+	if (netif_running(vi->dev))
+		napi_disable(&vi->napi);
+
+	remove_vq_common(vi);
+
+	return 0;
+}
+
+static int virtnet_restore(struct virtio_device *vdev)
+{
+	struct virtnet_info *vi = vdev->priv;
+	int err;
+
+	err = init_vqs(vi);
+	if (err)
+		return err;
+
+	if (netif_running(vi->dev))
+		virtnet_napi_enable(vi);
+
+	netif_device_attach(vi->dev);
+
+	if (!try_fill_recv(vi, GFP_KERNEL))
+		queue_delayed_work(system_nrt_wq, &vi->refill, 0);
+
+	return 0;
+}
+#endif
+
+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,
+#ifdef CONFIG_PM
+	.freeze =	virtnet_freeze,
+	.restore =	virtnet_restore,
+#endif
+};
+
+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");