Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest: (45 commits)
  Use "struct boot_params" in example launcher
  Loading bzImage directly.
  Revert lguest magic and use hook in head.S
  Update lguest documentation to reflect the new virtual block device name.
  generalize lgread_u32/lgwrite_u32.
  Example launcher handle guests not being ready for input
  Update example launcher for virtio
  Lguest support for Virtio
  Remove old lguest I/O infrrasructure.
  Remove old lguest bus and drivers.
  Virtio helper routines for a descriptor ringbuffer implementation
  Module autoprobing support for virtio drivers.
  Virtio console driver
  Block driver using virtio.
  Net driver using virtio
  Virtio interface
  Boot with virtual == physical to get closer to native Linux.
  Allow guest to specify syscall vector to use.
  Rename "cr3" to "gpgdir" to avoid x86-specific naming.
  Pagetables to use normal kernel types
  ...

4 files changed, 442 insertions, 556 deletions

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index ce34b539bf38..2538816817aa 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -3100,4 +3100,10 @@ config NETPOLL_TRAP
 config NET_POLL_CONTROLLER
 	def_bool NETPOLL
 
+config VIRTIO_NET
+	tristate "Virtio network driver (EXPERIMENTAL)"
+	depends on EXPERIMENTAL && VIRTIO
+	---help---
+	  This is the virtual network driver for lguest.  Say Y or M.
+
 endif # NETDEVICES
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 22f78cbd126b..593262065c9b 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -183,7 +183,6 @@ obj-$(CONFIG_ZORRO8390) += zorro8390.o
 obj-$(CONFIG_HPLANCE) += hplance.o 7990.o
 obj-$(CONFIG_MVME147_NET) += mvme147.o 7990.o
 obj-$(CONFIG_EQUALIZER) += eql.o
-obj-$(CONFIG_LGUEST_NET) += lguest_net.o
 obj-$(CONFIG_MIPS_JAZZ_SONIC) += jazzsonic.o
 obj-$(CONFIG_MIPS_AU1X00_ENET) += au1000_eth.o
 obj-$(CONFIG_MIPS_SIM_NET) += mipsnet.o
@@ -243,3 +242,4 @@ obj-$(CONFIG_FS_ENET) += fs_enet/
 
 obj-$(CONFIG_NETXEN_NIC) += netxen/
 obj-$(CONFIG_NIU) += niu.o
+obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
diff --git a/drivers/net/lguest_net.c b/drivers/net/lguest_net.c
deleted file mode 100644
index abce2ee8430a..000000000000
--- a/drivers/net/lguest_net.c
+++ /dev/null
@@ -1,555 +0,0 @@
-/*D:500
- * The Guest network driver.
- *
- * This is very simple a virtual network driver, and our last Guest driver.
- * The only trick is that it can talk directly to multiple other recipients
- * (ie. other Guests on the same network).  It can also be used with only the
- * Host on the network.
- :*/
-
-/* Copyright 2006 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/module.h>
-#include <linux/mm_types.h>
-#include <linux/io.h>
-#include <linux/lguest_bus.h>
-
-#define SHARED_SIZE		PAGE_SIZE
-#define MAX_LANS		4
-#define NUM_SKBS		8
-
-/*M:011 Network code master Jeff Garzik points out numerous shortcomings in
- * this driver if it aspires to greatness.
- *
- * Firstly, it doesn't use "NAPI": the networking's New API, and is poorer for
- * it.  As he says "NAPI means system-wide load leveling, across multiple
- * network interfaces.  Lack of NAPI can mean competition at higher loads."
- *
- * He also points out that we don't implement set_mac_address, so users cannot
- * change the devices hardware address.  When I asked why one would want to:
- * "Bonding, and situations where you /do/ want the MAC address to "leak" out
- * of the host onto the wider net."
- *
- * Finally, he would like module unloading: "It is not unrealistic to think of
- * [un|re|]loading the net support module in an lguest guest.  And, adding
- * module support makes the programmer more responsible, because they now have
- * to learn to clean up after themselves.  Any driver that cannot clean up
- * after itself is an incomplete driver in my book."
- :*/
-
-/*D:530 The "struct lguestnet_info" contains all the information we need to
- * know about the network device. */
-struct lguestnet_info
-{
-	/* The mapped device page(s) (an array of "struct lguest_net"). */
-	struct lguest_net *peer;
-	/* The physical address of the device page(s) */
-	unsigned long peer_phys;
-	/* The size of the device page(s). */
-	unsigned long mapsize;
-
-	/* The lguest_device I come from */
-	struct lguest_device *lgdev;
-
-	/* My peerid (ie. my slot in the array). */
-	unsigned int me;
-
-	/* Receive queue: the network packets waiting to be filled. */
-	struct sk_buff *skb[NUM_SKBS];
-	struct lguest_dma dma[NUM_SKBS];
-};
-/*:*/
-
-/* How many bytes left in this page. */
-static unsigned int rest_of_page(void *data)
-{
-	return PAGE_SIZE - ((unsigned long)data % PAGE_SIZE);
-}
-
-/*D:570 Each peer (ie. Guest or Host) on the network binds their receive
- * buffers to a different key: we simply use the physical address of the
- * device's memory page plus the peer number.  The Host insists that all keys
- * be a multiple of 4, so we multiply the peer number by 4. */
-static unsigned long peer_key(struct lguestnet_info *info, unsigned peernum)
-{
-	return info->peer_phys + 4 * peernum;
-}
-
-/* This is the routine which sets up a "struct lguest_dma" to point to a
- * network packet, similar to req_to_dma() in lguest_blk.c.  The structure of a
- * "struct sk_buff" has grown complex over the years: it consists of a "head"
- * linear section pointed to by "skb->data", and possibly an array of
- * "fragments" in the case of a non-linear packet.
- *
- * Our receive buffers don't use fragments at all but outgoing skbs might, so
- * we handle it. */
-static void skb_to_dma(const struct sk_buff *skb, unsigned int headlen,
-		       struct lguest_dma *dma)
-{
-	unsigned int i, seg;
-
-	/* First, we put the linear region into the "struct lguest_dma".  Each
-	 * entry can't go over a page boundary, so even though all our packets
-	 * are 1514 bytes or less, we might need to use two entries here: */
-	for (i = seg = 0; i < headlen; seg++, i += rest_of_page(skb->data+i)) {
-		dma->addr[seg] = virt_to_phys(skb->data + i);
-		dma->len[seg] = min((unsigned)(headlen - i),
-				    rest_of_page(skb->data + i));
-	}
-
-	/* Now we handle the fragments: at least they're guaranteed not to go
-	 * over a page.  skb_shinfo(skb) returns a pointer to the structure
-	 * which tells us about the number of fragments and the fragment
-	 * array. */
-	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++, seg++) {
-		const skb_frag_t *f = &skb_shinfo(skb)->frags[i];
-		/* Should not happen with MTU less than 64k - 2 * PAGE_SIZE. */
-		if (seg == LGUEST_MAX_DMA_SECTIONS) {
-			/* We will end up sending a truncated packet should
-			 * this ever happen.  Plus, a cool log message! */
-			printk("Woah dude!  Megapacket!\n");
-			break;
-		}
-		dma->addr[seg] = page_to_phys(f->page) + f->page_offset;
-		dma->len[seg] = f->size;
-	}
-
-	/* If after all that we didn't use the entire "struct lguest_dma"
-	 * array, we terminate it with a 0 length. */
-	if (seg < LGUEST_MAX_DMA_SECTIONS)
-		dma->len[seg] = 0;
-}
-
-/*
- * Packet transmission.
- *
- * Our packet transmission is a little unusual.  A real network card would just
- * send out the packet and leave the receivers to decide if they're interested.
- * Instead, we look through the network device memory page and see if any of
- * the ethernet addresses match the packet destination, and if so we send it to
- * that Guest.
- *
- * This is made a little more complicated in two cases.  The first case is
- * broadcast packets: for that we send the packet to all Guests on the network,
- * one at a time.  The second case is "promiscuous" mode, where a Guest wants
- * to see all the packets on the network.  We need a way for the Guest to tell
- * us it wants to see all packets, so it sets the "multicast" bit on its
- * published MAC address, which is never valid in a real ethernet address.
- */
-#define PROMISC_BIT		0x01
-
-/* This is the callback which is summoned whenever the network device's
- * multicast or promiscuous state changes.  If the card is in promiscuous mode,
- * we advertise that in our ethernet address in the device's memory.  We do the
- * same if Linux wants any or all multicast traffic.  */
-static void lguestnet_set_multicast(struct net_device *dev)
-{
-	struct lguestnet_info *info = netdev_priv(dev);
-
-	if ((dev->flags & (IFF_PROMISC|IFF_ALLMULTI)) || dev->mc_count)
-		info->peer[info->me].mac[0] |= PROMISC_BIT;
-	else
-		info->peer[info->me].mac[0] &= ~PROMISC_BIT;
-}
-
-/* A simple test function to see if a peer wants to see all packets.*/
-static int promisc(struct lguestnet_info *info, unsigned int peer)
-{
-	return info->peer[peer].mac[0] & PROMISC_BIT;
-}
-
-/* Another simple function to see if a peer's advertised ethernet address
- * matches a packet's destination ethernet address. */
-static int mac_eq(const unsigned char mac[ETH_ALEN],
-		  struct lguestnet_info *info, unsigned int peer)
-{
-	/* Ignore multicast bit, which peer turns on to mean promisc. */
-	if ((info->peer[peer].mac[0] & (~PROMISC_BIT)) != mac[0])
-		return 0;
-	return memcmp(mac+1, info->peer[peer].mac+1, ETH_ALEN-1) == 0;
-}
-
-/* This is the function which actually sends a packet once we've decided a
- * peer wants it: */
-static void transfer_packet(struct net_device *dev,
-			    struct sk_buff *skb,
-			    unsigned int peernum)
-{
-	struct lguestnet_info *info = netdev_priv(dev);
-	struct lguest_dma dma;
-
-	/* We use our handy "struct lguest_dma" packing function to prepare
-	 * the skb for sending. */
-	skb_to_dma(skb, skb_headlen(skb), &dma);
-	pr_debug("xfer length %04x (%u)\n", htons(skb->len), skb->len);
-
-	/* This is the actual send call which copies the packet. */
-	lguest_send_dma(peer_key(info, peernum), &dma);
-
-	/* Check that the entire packet was transmitted.  If not, it could mean
-	 * that the other Guest registered a short receive buffer, but this
-	 * driver should never do that.  More likely, the peer is dead. */
-	if (dma.used_len != skb->len) {
-		dev->stats.tx_carrier_errors++;
-		pr_debug("Bad xfer to peer %i: %i of %i (dma %p/%i)\n",
-			 peernum, dma.used_len, skb->len,
-			 (void *)dma.addr[0], dma.len[0]);
-	} else {
-		/* On success we update the stats. */
-		dev->stats.tx_bytes += skb->len;
-		dev->stats.tx_packets++;
-	}
-}
-
-/* Another helper function to tell is if a slot in the device memory is unused.
- * Since we always set the Local Assignment bit in the ethernet address, the
- * first byte can never be 0. */
-static int unused_peer(const struct lguest_net peer[], unsigned int num)
-{
-	return peer[num].mac[0] == 0;
-}
-
-/* Finally, here is the routine which handles an outgoing packet.  It's called
- * "start_xmit" for traditional reasons. */
-static int lguestnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
-{
-	unsigned int i;
-	int broadcast;
-	struct lguestnet_info *info = netdev_priv(dev);
-	/* Extract the destination ethernet address from the packet. */
-	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
-	DECLARE_MAC_BUF(mac);
-
-	pr_debug("%s: xmit %s\n", dev->name, print_mac(mac, dest));
-
-	/* If it's a multicast packet, we broadcast to everyone.  That's not
-	 * very efficient, but there are very few applications which actually
-	 * use multicast, which is a shame really.
-	 *
-	 * As etherdevice.h points out: "By definition the broadcast address is
-	 * also a multicast address."  So we don't have to test for broadcast
-	 * packets separately. */
-	broadcast = is_multicast_ether_addr(dest);
-
-	/* Look through all the published ethernet addresses to see if we
-	 * should send this packet. */
-	for (i = 0; i < info->mapsize/sizeof(struct lguest_net); i++) {
-		/* We don't send to ourselves (we actually can't SEND_DMA to
-		 * ourselves anyway), and don't send to unused slots.*/
-		if (i == info->me || unused_peer(info->peer, i))
-			continue;
-
-		/* If it's broadcast we send it.  If they want every packet we
-		 * send it.  If the destination matches their address we send
-		 * it.  Otherwise we go to the next peer. */
-		if (!broadcast && !promisc(info, i) && !mac_eq(dest, info, i))
-			continue;
-
-		pr_debug("lguestnet %s: sending from %i to %i\n",
-			 dev->name, info->me, i);
-		/* Our routine which actually does the transfer. */
-		transfer_packet(dev, skb, i);
-	}
-
-	/* An xmit routine is expected to dispose of the packet, so we do. */
-	dev_kfree_skb(skb);
-
-	/* As per kernel convention, 0 means success.  This is why I love
-	 * networking: even if we never sent to anyone, that's still
-	 * success! */
-	return 0;
-}
-
-/*D:560
- * Packet receiving.
- *
- * First, here's a helper routine which fills one of our array of receive
- * buffers: */
-static int fill_slot(struct net_device *dev, unsigned int slot)
-{
-	struct lguestnet_info *info = netdev_priv(dev);
-
-	/* We can receive ETH_DATA_LEN (1500) byte packets, plus a standard
-	 * ethernet header of ETH_HLEN (14) bytes. */
-	info->skb[slot] = netdev_alloc_skb(dev, ETH_HLEN + ETH_DATA_LEN);
-	if (!info->skb[slot]) {
-		printk("%s: could not fill slot %i\n", dev->name, slot);
-		return -ENOMEM;
-	}
-
-	/* skb_to_dma() is a helper which sets up the "struct lguest_dma" to
-	 * point to the data in the skb: we also use it for sending out a
-	 * packet. */
-	skb_to_dma(info->skb[slot], ETH_HLEN + ETH_DATA_LEN, &info->dma[slot]);
-
-	/* This is a Write Memory Barrier: it ensures that the entry in the
-	 * receive buffer array is written *before* we set the "used_len" entry
-	 * to 0.  If the Host were looking at the receive buffer array from a
-	 * different CPU, it could potentially see "used_len = 0" and not see
-	 * the updated receive buffer information.  This would be a horribly
-	 * nasty bug, so make sure the compiler and CPU know this has to happen
-	 * first. */
-	wmb();
-	/* Writing 0 to "used_len" tells the Host it can use this receive
-	 * buffer now. */
-	info->dma[slot].used_len = 0;
-	return 0;
-}
-
-/* This is the actual receive routine.  When we receive an interrupt from the
- * Host to tell us a packet has been delivered, we arrive here: */
-static irqreturn_t lguestnet_rcv(int irq, void *dev_id)
-{
-	struct net_device *dev = dev_id;
-	struct lguestnet_info *info = netdev_priv(dev);
-	unsigned int i, done = 0;
-
-	/* Look through our entire receive array for an entry which has data
-	 * in it. */
-	for (i = 0; i < ARRAY_SIZE(info->dma); i++) {
-		unsigned int length;
-		struct sk_buff *skb;
-
-		length = info->dma[i].used_len;
-		if (length == 0)
-			continue;
-
-		/* We've found one!  Remember the skb (we grabbed the length
-		 * above), and immediately refill the slot we've taken it
-		 * from. */
-		done++;
-		skb = info->skb[i];
-		fill_slot(dev, i);
-
-		/* This shouldn't happen: micropackets could be sent by a
-		 * badly-behaved Guest on the network, but the Host will never
-		 * stuff more data in the buffer than the buffer length. */
-		if (length < ETH_HLEN || length > ETH_HLEN + ETH_DATA_LEN) {
-			pr_debug(KERN_WARNING "%s: unbelievable skb len: %i\n",
-				 dev->name, length);
-			dev_kfree_skb(skb);
-			continue;
-		}
-
-		/* skb_put(), what a great function!  I've ranted about this
-		 * function before (http://lkml.org/lkml/1999/9/26/24).  You
-		 * call it after you've added data to the end of an skb (in
-		 * this case, it was the Host which wrote the data). */
-		skb_put(skb, length);
-
-		/* The ethernet header contains a protocol field: we use the
-		 * standard helper to extract it, and place the result in
-		 * skb->protocol.  The helper also sets up skb->pkt_type and
-		 * eats up the ethernet header from the front of the packet. */
-		skb->protocol = eth_type_trans(skb, dev);
-
-		/* If this device doesn't need checksums for sending, we also
-		 * don't need to check the packets when they come in. */
-		if (dev->features & NETIF_F_NO_CSUM)
-			skb->ip_summed = CHECKSUM_UNNECESSARY;
-
-		/* As a last resort for debugging the driver or the lguest I/O
-		 * subsystem, you can uncomment the "#define DEBUG" at the top
-		 * of this file, which turns all the pr_debug() into printk()
-		 * and floods the logs. */
-		pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
-			 ntohs(skb->protocol), skb->len, skb->pkt_type);
-
-		/* Update the packet and byte counts (visible from ifconfig,
-		 * and good for debugging). */
-		dev->stats.rx_bytes += skb->len;
-		dev->stats.rx_packets++;
-
-		/* Hand our fresh network packet into the stack's "network
-		 * interface receive" routine.  That will free the packet
-		 * itself when it's finished. */
-		netif_rx(skb);
-	}
-
-	/* If we found any packets, we assume the interrupt was for us. */
-	return done ? IRQ_HANDLED : IRQ_NONE;
-}
-
-/*D:550 This is where we start: when the device is brought up by dhcpd or
- * ifconfig.  At this point we advertise our MAC address to the rest of the
- * network, and register receive buffers ready for incoming packets. */
-static int lguestnet_open(struct net_device *dev)
-{
-	int i;
-	struct lguestnet_info *info = netdev_priv(dev);
-
-	/* Copy our MAC address into the device page, so others on the network
-	 * can find us. */
-	memcpy(info->peer[info->me].mac, dev->dev_addr, ETH_ALEN);
-
-	/* We might already be in promisc mode (dev->flags & IFF_PROMISC).  Our
-	 * set_multicast callback handles this already, so we call it now. */
-	lguestnet_set_multicast(dev);
-
-	/* Allocate packets and put them into our "struct lguest_dma" array.
-	 * If we fail to allocate all the packets we could still limp along,
-	 * but it's a sign of real stress so we should probably give up now. */
-	for (i = 0; i < ARRAY_SIZE(info->dma); i++) {
-		if (fill_slot(dev, i) != 0)
-			goto cleanup;
-	}
-
-	/* Finally we tell the Host where our array of "struct lguest_dma"
-	 * receive buffers is, binding it to the key corresponding to the
-	 * device's physical memory plus our peerid. */
-	if (lguest_bind_dma(peer_key(info,info->me), info->dma,
-			    NUM_SKBS, lgdev_irq(info->lgdev)) != 0)
-		goto cleanup;
-	return 0;
-
-cleanup:
-	while (--i >= 0)
-		dev_kfree_skb(info->skb[i]);
-	return -ENOMEM;
-}
-/*:*/
-
-/* The close routine is called when the device is no longer in use: we clean up
- * elegantly. */
-static int lguestnet_close(struct net_device *dev)
-{
-	unsigned int i;
-	struct lguestnet_info *info = netdev_priv(dev);
-
-	/* Clear all trace of our existence out of the device memory by setting
-	 * the slot which held our MAC address to 0 (unused). */
-	memset(&info->peer[info->me], 0, sizeof(info->peer[info->me]));
-
-	/* Unregister our array of receive buffers */
-	lguest_unbind_dma(peer_key(info, info->me), info->dma);
-	for (i = 0; i < ARRAY_SIZE(info->dma); i++)
-		dev_kfree_skb(info->skb[i]);
-	return 0;
-}
-
-/*D:510 The network device probe function is basically a standard ethernet
- * device setup.  It reads the "struct lguest_device_desc" and sets the "struct
- * net_device".  Oh, the line-by-line excitement!  Let's skip over it. :*/
-static int lguestnet_probe(struct lguest_device *lgdev)
-{
-	int err, irqf = IRQF_SHARED;
-	struct net_device *dev;
-	struct lguestnet_info *info;
-	struct lguest_device_desc *desc = &lguest_devices[lgdev->index];
-
-	pr_debug("lguest_net: probing for device %i\n", lgdev->index);
-
-	dev = alloc_etherdev(sizeof(struct lguestnet_info));
-	if (!dev)
-		return -ENOMEM;
-
-	/* Ethernet defaults with some changes */
-	ether_setup(dev);
-	dev->set_mac_address = NULL;
-
-	dev->dev_addr[0] = 0x02; /* set local assignment bit (IEEE802) */
-	dev->dev_addr[1] = 0x00;
-	memcpy(&dev->dev_addr[2], &lguest_data.guestid, 2);
-	dev->dev_addr[4] = 0x00;
-	dev->dev_addr[5] = 0x00;
-
-	dev->open = lguestnet_open;
-	dev->stop = lguestnet_close;
-	dev->hard_start_xmit = lguestnet_start_xmit;
-
-	/* We don't actually support multicast yet, but turning on/off
-	 * promisc also calls dev->set_multicast_list. */
-	dev->set_multicast_list = lguestnet_set_multicast;
-	SET_NETDEV_DEV(dev, &lgdev->dev);
-
-	/* The network code complains if you have "scatter-gather" capability
-	 * if you don't also handle checksums (it seem that would be
-	 * "illogical").  So we use a lie of omission and don't tell it that we
-	 * can handle scattered packets unless we also don't want checksums,
-	 * even though to us they're completely independent. */
-	if (desc->features & LGUEST_NET_F_NOCSUM)
-		dev->features = NETIF_F_SG|NETIF_F_NO_CSUM;
-
-	info = netdev_priv(dev);
-	info->mapsize = PAGE_SIZE * desc->num_pages;
-	info->peer_phys = ((unsigned long)desc->pfn << PAGE_SHIFT);
-	info->lgdev = lgdev;
-	info->peer = lguest_map(info->peer_phys, desc->num_pages);
-	if (!info->peer) {
-		err = -ENOMEM;
-		goto free;
-	}
-
-	/* This stores our peerid (upper bits reserved for future). */
-	info->me = (desc->features & (info->mapsize-1));
-
-	err = register_netdev(dev);
-	if (err) {
-		pr_debug("lguestnet: registering device failed\n");
-		goto unmap;
-	}
-
-	if (lguest_devices[lgdev->index].features & LGUEST_DEVICE_F_RANDOMNESS)
-		irqf |= IRQF_SAMPLE_RANDOM;
-	if (request_irq(lgdev_irq(lgdev), lguestnet_rcv, irqf, "lguestnet",
-			dev) != 0) {
-		pr_debug("lguestnet: cannot get irq %i\n", lgdev_irq(lgdev));
-		goto unregister;
-	}
-
-	pr_debug("lguestnet: registered device %s\n", dev->name);
-	/* Finally, we put the "struct net_device" in the generic "struct
-	 * lguest_device"s private pointer.  Again, it's not necessary, but
-	 * makes sure the cool kernel kids don't tease us. */
-	lgdev->private = dev;
-	return 0;
-
-unregister:
-	unregister_netdev(dev);
-unmap:
-	lguest_unmap(info->peer);
-free:
-	free_netdev(dev);
-	return err;
-}
-
-static struct lguest_driver lguestnet_drv = {
-	.name = "lguestnet",
-	.owner = THIS_MODULE,
-	.device_type = LGUEST_DEVICE_T_NET,
-	.probe = lguestnet_probe,
-};
-
-static __init int lguestnet_init(void)
-{
-	return register_lguest_driver(&lguestnet_drv);
-}
-module_init(lguestnet_init);
-
-MODULE_DESCRIPTION("Lguest network driver");
-MODULE_LICENSE("GPL");
-
-/*D:580
- * This is the last of the Drivers, and with this we have covered the many and
- * wonderous and fine (and boring) details of the Guest.
- *
- * "make Launcher" beckons, where we answer questions like "Where do Guests
- * come from?", and "What do you do when someone asks for optimization?"
- */
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
new file mode 100644
index 000000000000..e396c9d2af8d
--- /dev/null
+++ b/drivers/net/virtio_net.c
@@ -0,0 +1,435 @@
+/* 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>
+#include <linux/module.h>
+#include <linux/virtio.h>
+#include <linux/virtio_net.h>
+#include <linux/scatterlist.h>
+
+/* FIXME: MTU in config. */
+#define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
+
+struct virtnet_info
+{
+	struct virtio_device *vdev;
+	struct virtqueue *rvq, *svq;
+	struct net_device *dev;
+	struct napi_struct napi;
+
+	/* Number of input buffers, and max we've ever had. */
+	unsigned int num, max;
+
+	/* Receive & send queues. */
+	struct sk_buff_head recv;
+	struct sk_buff_head send;
+};
+
+static inline struct virtio_net_hdr *skb_vnet_hdr(struct sk_buff *skb)
+{
+	return (struct virtio_net_hdr *)skb->cb;
+}
+
+static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
+{
+	sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
+}
+
+static bool skb_xmit_done(struct virtqueue *rvq)
+{
+	struct virtnet_info *vi = rvq->vdev->priv;
+
+	/* In case we were waiting for output buffers. */
+	netif_wake_queue(vi->dev);
+	return true;
+}
+
+static void receive_skb(struct net_device *dev, struct sk_buff *skb,
+			unsigned len)
+{
+	struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
+
+	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;
+	}
+	len -= sizeof(struct virtio_net_hdr);
+	BUG_ON(len > MAX_PACKET_LEN);
+
+	skb_trim(skb, len);
+	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);
+	dev->stats.rx_bytes += skb->len;
+	dev->stats.rx_packets++;
+
+	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
+		pr_debug("Needs csum!\n");
+		skb->ip_summed = CHECKSUM_PARTIAL;
+		skb->csum_start = hdr->csum_start;
+		skb->csum_offset = hdr->csum_offset;
+		if (skb->csum_start > skb->len - 2
+		    || skb->csum_offset > skb->len - 2) {
+			if (net_ratelimit())
+				printk(KERN_WARNING "%s: csum=%u/%u len=%u\n",
+				       dev->name, skb->csum_start,
+				       skb->csum_offset, skb->len);
+			goto frame_err;
+		}
+	}
+
+	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
+		pr_debug("GSO!\n");
+		switch (hdr->gso_type) {
+		case VIRTIO_NET_HDR_GSO_TCPV4:
+			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
+			break;
+		case VIRTIO_NET_HDR_GSO_TCPV4_ECN:
+			skb_shinfo(skb)->gso_type = SKB_GSO_TCP_ECN;
+			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;
+		}
+
+		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);
+}
+
+static void try_fill_recv(struct virtnet_info *vi)
+{
+	struct sk_buff *skb;
+	struct scatterlist sg[1+MAX_SKB_FRAGS];
+	int num, err;
+
+	for (;;) {
+		skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
+		if (unlikely(!skb))
+			break;
+
+		skb_put(skb, MAX_PACKET_LEN);
+		vnet_hdr_to_sg(sg, skb);
+		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);
+			kfree_skb(skb);
+			break;
+		}
+		vi->num++;
+	}
+	if (unlikely(vi->num > vi->max))
+		vi->max = vi->num;
+	vi->rvq->vq_ops->kick(vi->rvq);
+}
+
+static bool skb_recv_done(struct virtqueue *rvq)
+{
+	struct virtnet_info *vi = rvq->vdev->priv;
+	netif_rx_schedule(vi->dev, &vi->napi);
+	/* Suppress further interrupts. */
+	return false;
+}
+
+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);
+
+	/* All done? */
+	if (!skb) {
+		netif_rx_complete(vi->dev, napi);
+		if (unlikely(!vi->rvq->vq_ops->restart(vi->rvq))
+		    && netif_rx_reschedule(vi->dev, napi))
+			goto again;
+	}
+
+	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);
+		vi->dev->stats.tx_bytes += len;
+		vi->dev->stats.tx_packets++;
+		kfree_skb(skb);
+	}
+}
+
+static int start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	int num, err;
+	struct scatterlist sg[1+MAX_SKB_FRAGS];
+	struct virtio_net_hdr *hdr;
+	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
+	DECLARE_MAC_BUF(mac);
+
+	pr_debug("%s: xmit %p %s\n", dev->name, skb, print_mac(mac, dest));
+
+	free_old_xmit_skbs(vi);
+
+	/* Encode metadata header at front. */
+	hdr = skb_vnet_hdr(skb);
+	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)) {
+		hdr->gso_size = skb_shinfo(skb)->gso_size;
+		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
+			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4_ECN;
+		else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+			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();
+	} else {
+		hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
+		hdr->gso_size = 0;
+	}
+
+	vnet_hdr_to_sg(sg, skb);
+	num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
+	__skb_queue_head(&vi->send, skb);
+	err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
+	if (err) {
+		pr_debug("%s: virtio not prepared to send\n", dev->name);
+		skb_unlink(skb, &vi->send);
+		netif_stop_queue(dev);
+		return NETDEV_TX_BUSY;
+	}
+	vi->svq->vq_ops->kick(vi->svq);
+
+	return 0;
+}
+
+static int virtnet_open(struct net_device *dev)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+
+	try_fill_recv(vi);
+
+	/* If we didn't even get one input buffer, we're useless. */
+	if (vi->num == 0)
+		return -ENOMEM;
+
+	napi_enable(&vi->napi);
+	return 0;
+}
+
+static int virtnet_close(struct net_device *dev)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	struct sk_buff *skb;
+
+	napi_disable(&vi->napi);
+
+	/* networking core has neutered skb_xmit_done/skb_recv_done, so don't
+	 * worry about races vs. get(). */
+	vi->rvq->vq_ops->shutdown(vi->rvq);
+	while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
+		kfree_skb(skb);
+		vi->num--;
+	}
+	vi->svq->vq_ops->shutdown(vi->svq);
+	while ((skb = __skb_dequeue(&vi->send)) != NULL)
+		kfree_skb(skb);
+
+	BUG_ON(vi->num != 0);
+	return 0;
+}
+
+static int virtnet_probe(struct virtio_device *vdev)
+{
+	int err;
+	unsigned int len;
+	struct net_device *dev;
+	struct virtnet_info *vi;
+	void *token;
+
+	/* 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. */
+	ether_setup(dev);
+	dev->open = virtnet_open;
+	dev->stop = virtnet_close;
+	dev->hard_start_xmit = start_xmit;
+	dev->features = NETIF_F_HIGHDMA;
+	SET_NETDEV_DEV(dev, &vdev->dev);
+
+	/* Do we support "hardware" checksums? */
+	token = vdev->config->find(vdev, VIRTIO_CONFIG_NET_F, &len);
+	if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_NO_CSUM)) {
+		/* This opens up the world of extra features. */
+		dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
+		if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_TSO4))
+			dev->features |= NETIF_F_TSO;
+		if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_UFO))
+			dev->features |= NETIF_F_UFO;
+		if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_TSO4_ECN))
+			dev->features |= NETIF_F_TSO_ECN;
+		if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_TSO6))
+			dev->features |= NETIF_F_TSO6;
+	}
+
+	/* Configuration may specify what MAC to use.  Otherwise random. */
+	token = vdev->config->find(vdev, VIRTIO_CONFIG_NET_MAC_F, &len);
+	if (token) {
+		dev->addr_len = len;
+		vdev->config->get(vdev, token, dev->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, 16);
+	vi->dev = dev;
+	vi->vdev = vdev;
+
+	/* We expect two virtqueues, receive then send. */
+	vi->rvq = vdev->config->find_vq(vdev, skb_recv_done);
+	if (IS_ERR(vi->rvq)) {
+		err = PTR_ERR(vi->rvq);
+		goto free;
+	}
+
+	vi->svq = vdev->config->find_vq(vdev, skb_xmit_done);
+	if (IS_ERR(vi->svq)) {
+		err = PTR_ERR(vi->svq);
+		goto free_recv;
+	}
+
+	/* Initialize our empty receive and send queues. */
+	skb_queue_head_init(&vi->recv);
+	skb_queue_head_init(&vi->send);
+
+	err = register_netdev(dev);
+	if (err) {
+		pr_debug("virtio_net: registering device failed\n");
+		goto free_send;
+	}
+	pr_debug("virtnet: registered device %s\n", dev->name);
+	vdev->priv = vi;
+	return 0;
+
+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)
+{
+	unregister_netdev(vdev->priv);
+	free_netdev(vdev->priv);
+}
+
+static struct virtio_device_id id_table[] = {
+	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
+	{ 0 },
+};
+
+static struct virtio_driver virtio_net = {
+	.driver.name =	KBUILD_MODNAME,
+	.driver.owner =	THIS_MODULE,
+	.id_table =	id_table,
+	.probe =	virtnet_probe,
+	.remove =	__devexit_p(virtnet_remove),
+};
+
+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");