Move kvm, uml, and lguest subdirectories under a common "virtual" directory, I.E:

  cd Documentation
  mkdir virtual
  git mv kvm uml lguest virtual

Signed-off-by: Rob Landley <rlandley@parallels.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>

5 files changed, 0 insertions, 2290 deletions

diff --git a/Documentation/lguest/.gitignore b/Documentation/lguest/.gitignore
deleted file mode 100644
index 115587fd5f65..000000000000
--- a/Documentation/lguest/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-lguest
diff --git a/Documentation/lguest/Makefile b/Documentation/lguest/Makefile
deleted file mode 100644
index bebac6b4f332..000000000000
--- a/Documentation/lguest/Makefile
+++ /dev/null
@@ -1,8 +0,0 @@
-# This creates the demonstration utility "lguest" which runs a Linux guest.
-# Missing headers?  Add "-I../../include -I../../arch/x86/include"
-CFLAGS:=-m32 -Wall -Wmissing-declarations -Wmissing-prototypes -O3 -U_FORTIFY_SOURCE
-
-all: lguest
-
-clean:
-	rm -f lguest
diff --git a/Documentation/lguest/extract b/Documentation/lguest/extract
deleted file mode 100644
index 7730bb6e4b94..000000000000
--- a/Documentation/lguest/extract
+++ /dev/null
@@ -1,58 +0,0 @@
-#! /bin/sh
-
-set -e
-
-PREFIX=$1
-shift
-
-trap 'rm -r $TMPDIR' 0
-TMPDIR=`mktemp -d`
-
-exec 3>/dev/null
-for f; do
-    while IFS="
-" read -r LINE; do
-	case "$LINE" in
-	    *$PREFIX:[0-9]*:\**)
-		NUM=`echo "$LINE" | sed "s/.*$PREFIX:\([0-9]*\).*/\1/"`
-		if [ -f $TMPDIR/$NUM ]; then
-		    echo "$TMPDIR/$NUM already exits prior to $f"
-		    exit 1
-		fi
-		exec 3>>$TMPDIR/$NUM
-		echo $f | sed 's,\.\./,,g' > $TMPDIR/.$NUM
-		/bin/echo "$LINE" | sed -e "s/$PREFIX:[0-9]*//" -e "s/:\*/*/" >&3
-		;;
-	    *$PREFIX:[0-9]*)
-		NUM=`echo "$LINE" | sed "s/.*$PREFIX:\([0-9]*\).*/\1/"`
-		if [ -f $TMPDIR/$NUM ]; then
-		    echo "$TMPDIR/$NUM already exits prior to $f"
-		    exit 1
-		fi
-		exec 3>>$TMPDIR/$NUM
-		echo $f | sed 's,\.\./,,g' > $TMPDIR/.$NUM
-		/bin/echo "$LINE" | sed "s/$PREFIX:[0-9]*//" >&3
-		;;
-	    *:\**)
-		/bin/echo "$LINE" | sed -e "s/:\*/*/" -e "s,/\*\*/,," >&3
-		echo >&3
-		exec 3>/dev/null
-		;;
-	    *)
-		/bin/echo "$LINE" >&3
-		;;
-	esac
-    done < $f
-    echo >&3
-    exec 3>/dev/null
-done
-
-LASTFILE=""
-for f in $TMPDIR/*; do
-    if [ "$LASTFILE" != $(cat $TMPDIR/.$(basename $f) ) ]; then
-	LASTFILE=$(cat $TMPDIR/.$(basename $f) )
-	echo "[ $LASTFILE ]"
-    fi
-    cat $f
-done
-
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
deleted file mode 100644
index d9da7e148538..000000000000
--- a/Documentation/lguest/lguest.c
+++ /dev/null
@@ -1,2095 +0,0 @@
-/*P:100
- * This is the Launcher code, a simple program which lays out the "physical"
- * memory for the new Guest by mapping the kernel image and the virtual
- * devices, then opens /dev/lguest to tell the kernel about the Guest and
- * control it.
-:*/
-#define _LARGEFILE64_SOURCE
-#define _GNU_SOURCE
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-#include <err.h>
-#include <stdint.h>
-#include <stdlib.h>
-#include <elf.h>
-#include <sys/mman.h>
-#include <sys/param.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/wait.h>
-#include <sys/eventfd.h>
-#include <fcntl.h>
-#include <stdbool.h>
-#include <errno.h>
-#include <ctype.h>
-#include <sys/socket.h>
-#include <sys/ioctl.h>
-#include <sys/time.h>
-#include <time.h>
-#include <netinet/in.h>
-#include <net/if.h>
-#include <linux/sockios.h>
-#include <linux/if_tun.h>
-#include <sys/uio.h>
-#include <termios.h>
-#include <getopt.h>
-#include <assert.h>
-#include <sched.h>
-#include <limits.h>
-#include <stddef.h>
-#include <signal.h>
-#include <pwd.h>
-#include <grp.h>
-
-#include <linux/virtio_config.h>
-#include <linux/virtio_net.h>
-#include <linux/virtio_blk.h>
-#include <linux/virtio_console.h>
-#include <linux/virtio_rng.h>
-#include <linux/virtio_ring.h>
-#include <asm/bootparam.h>
-#include "../../include/linux/lguest_launcher.h"
-/*L:110
- * We can ignore the 42 include files we need for this program, but I do want
- * to draw attention to the use of kernel-style types.
- *
- * As Linus said, "C is a Spartan language, and so should your naming be."  I
- * like these abbreviations, so we define them here.  Note that u64 is always
- * unsigned long long, which works on all Linux systems: this means that we can
- * use %llu in printf for any u64.
- */
-typedef unsigned long long u64;
-typedef uint32_t u32;
-typedef uint16_t u16;
-typedef uint8_t u8;
-/*:*/
-
-#define PAGE_PRESENT 0x7 	/* Present, RW, Execute */
-#define BRIDGE_PFX "bridge:"
-#ifndef SIOCBRADDIF
-#define SIOCBRADDIF	0x89a2		/* add interface to bridge      */
-#endif
-/* We can have up to 256 pages for devices. */
-#define DEVICE_PAGES 256
-/* This will occupy 3 pages: it must be a power of 2. */
-#define VIRTQUEUE_NUM 256
-
-/*L:120
- * verbose is both a global flag and a macro.  The C preprocessor allows
- * this, and although I wouldn't recommend it, it works quite nicely here.
- */
-static bool verbose;
-#define verbose(args...) \
-	do { if (verbose) printf(args); } while(0)
-/*:*/
-
-/* The pointer to the start of guest memory. */
-static void *guest_base;
-/* The maximum guest physical address allowed, and maximum possible. */
-static unsigned long guest_limit, guest_max;
-/* The /dev/lguest file descriptor. */
-static int lguest_fd;
-
-/* a per-cpu variable indicating whose vcpu is currently running */
-static unsigned int __thread cpu_id;
-
-/* This is our list of devices. */
-struct device_list {
-	/* Counter to assign interrupt numbers. */
-	unsigned int next_irq;
-
-	/* Counter to print out convenient device numbers. */
-	unsigned int device_num;
-
-	/* The descriptor page for the devices. */
-	u8 *descpage;
-
-	/* A single linked list of devices. */
-	struct device *dev;
-	/* And a pointer to the last device for easy append. */
-	struct device *lastdev;
-};
-
-/* The list of Guest devices, based on command line arguments. */
-static struct device_list devices;
-
-/* The device structure describes a single device. */
-struct device {
-	/* The linked-list pointer. */
-	struct device *next;
-
-	/* The device's descriptor, as mapped into the Guest. */
-	struct lguest_device_desc *desc;
-
-	/* We can't trust desc values once Guest has booted: we use these. */
-	unsigned int feature_len;
-	unsigned int num_vq;
-
-	/* The name of this device, for --verbose. */
-	const char *name;
-
-	/* Any queues attached to this device */
-	struct virtqueue *vq;
-
-	/* Is it operational */
-	bool running;
-
-	/* Does Guest want an intrrupt on empty? */
-	bool irq_on_empty;
-
-	/* Device-specific data. */
-	void *priv;
-};
-
-/* The virtqueue structure describes a queue attached to a device. */
-struct virtqueue {
-	struct virtqueue *next;
-
-	/* Which device owns me. */
-	struct device *dev;
-
-	/* The configuration for this queue. */
-	struct lguest_vqconfig config;
-
-	/* The actual ring of buffers. */
-	struct vring vring;
-
-	/* Last available index we saw. */
-	u16 last_avail_idx;
-
-	/* How many are used since we sent last irq? */
-	unsigned int pending_used;
-
-	/* Eventfd where Guest notifications arrive. */
-	int eventfd;
-
-	/* Function for the thread which is servicing this virtqueue. */
-	void (*service)(struct virtqueue *vq);
-	pid_t thread;
-};
-
-/* Remember the arguments to the program so we can "reboot" */
-static char **main_args;
-
-/* The original tty settings to restore on exit. */
-static struct termios orig_term;
-
-/*
- * We have to be careful with barriers: our devices are all run in separate
- * threads and so we need to make sure that changes visible to the Guest happen
- * in precise order.
- */
-#define wmb() __asm__ __volatile__("" : : : "memory")
-#define mb() __asm__ __volatile__("" : : : "memory")
-
-/*
- * Convert an iovec element to the given type.
- *
- * This is a fairly ugly trick: we need to know the size of the type and
- * alignment requirement to check the pointer is kosher.  It's also nice to
- * have the name of the type in case we report failure.
- *
- * Typing those three things all the time is cumbersome and error prone, so we
- * have a macro which sets them all up and passes to the real function.
- */
-#define convert(iov, type) \
-	((type *)_convert((iov), sizeof(type), __alignof__(type), #type))
-
-static void *_convert(struct iovec *iov, size_t size, size_t align,
-		      const char *name)
-{
-	if (iov->iov_len != size)
-		errx(1, "Bad iovec size %zu for %s", iov->iov_len, name);
-	if ((unsigned long)iov->iov_base % align != 0)
-		errx(1, "Bad alignment %p for %s", iov->iov_base, name);
-	return iov->iov_base;
-}
-
-/* Wrapper for the last available index.  Makes it easier to change. */
-#define lg_last_avail(vq)	((vq)->last_avail_idx)
-
-/*
- * The virtio configuration space is defined to be little-endian.  x86 is
- * little-endian too, but it's nice to be explicit so we have these helpers.
- */
-#define cpu_to_le16(v16) (v16)
-#define cpu_to_le32(v32) (v32)
-#define cpu_to_le64(v64) (v64)
-#define le16_to_cpu(v16) (v16)
-#define le32_to_cpu(v32) (v32)
-#define le64_to_cpu(v64) (v64)
-
-/* Is this iovec empty? */
-static bool iov_empty(const struct iovec iov[], unsigned int num_iov)
-{
-	unsigned int i;
-
-	for (i = 0; i < num_iov; i++)
-		if (iov[i].iov_len)
-			return false;
-	return true;
-}
-
-/* Take len bytes from the front of this iovec. */
-static void iov_consume(struct iovec iov[], unsigned num_iov, unsigned len)
-{
-	unsigned int i;
-
-	for (i = 0; i < num_iov; i++) {
-		unsigned int used;
-
-		used = iov[i].iov_len < len ? iov[i].iov_len : len;
-		iov[i].iov_base += used;
-		iov[i].iov_len -= used;
-		len -= used;
-	}
-	assert(len == 0);
-}
-
-/* The device virtqueue descriptors are followed by feature bitmasks. */
-static u8 *get_feature_bits(struct device *dev)
-{
-	return (u8 *)(dev->desc + 1)
-		+ dev->num_vq * sizeof(struct lguest_vqconfig);
-}
-
-/*L:100
- * The Launcher code itself takes us out into userspace, that scary place where
- * pointers run wild and free!  Unfortunately, like most userspace programs,
- * it's quite boring (which is why everyone likes to hack on the kernel!).
- * Perhaps if you make up an Lguest Drinking Game at this point, it will get
- * you through this section.  Or, maybe not.
- *
- * The Launcher sets up a big chunk of memory to be the Guest's "physical"
- * memory and stores it in "guest_base".  In other words, Guest physical ==
- * Launcher virtual with an offset.
- *
- * This can be tough to get your head around, but usually it just means that we
- * use these trivial conversion functions when the Guest gives us its
- * "physical" addresses:
- */
-static void *from_guest_phys(unsigned long addr)
-{
-	return guest_base + addr;
-}
-
-static unsigned long to_guest_phys(const void *addr)
-{
-	return (addr - guest_base);
-}
-
-/*L:130
- * Loading the Kernel.
- *
- * We start with couple of simple helper routines.  open_or_die() avoids
- * error-checking code cluttering the callers:
- */
-static int open_or_die(const char *name, int flags)
-{
-	int fd = open(name, flags);
-	if (fd < 0)
-		err(1, "Failed to open %s", name);
-	return fd;
-}
-
-/* map_zeroed_pages() takes a number of pages. */
-static void *map_zeroed_pages(unsigned int num)
-{
-	int fd = open_or_die("/dev/zero", O_RDONLY);
-	void *addr;
-
-	/*
-	 * We use a private mapping (ie. if we write to the page, it will be
-	 * copied). We allocate an extra two pages PROT_NONE to act as guard
-	 * pages against read/write attempts that exceed allocated space.
-	 */
-	addr = mmap(NULL, getpagesize() * (num+2),
-		    PROT_NONE, MAP_PRIVATE, fd, 0);
-
-	if (addr == MAP_FAILED)
-		err(1, "Mmapping %u pages of /dev/zero", num);
-
-	if (mprotect(addr + getpagesize(), getpagesize() * num,
-		     PROT_READ|PROT_WRITE) == -1)
-		err(1, "mprotect rw %u pages failed", num);
-
-	/*
-	 * One neat mmap feature is that you can close the fd, and it
-	 * stays mapped.
-	 */
-	close(fd);
-
-	/* Return address after PROT_NONE page */
-	return addr + getpagesize();
-}
-
-/* Get some more pages for a device. */
-static void *get_pages(unsigned int num)
-{
-	void *addr = from_guest_phys(guest_limit);
-
-	guest_limit += num * getpagesize();
-	if (guest_limit > guest_max)
-		errx(1, "Not enough memory for devices");
-	return addr;
-}
-
-/*
- * This routine is used to load the kernel or initrd.  It tries mmap, but if
- * that fails (Plan 9's kernel file isn't nicely aligned on page boundaries),
- * it falls back to reading the memory in.
- */
-static void map_at(int fd, void *addr, unsigned long offset, unsigned long len)
-{
-	ssize_t r;
-
-	/*
-	 * We map writable even though for some segments are marked read-only.
-	 * The kernel really wants to be writable: it patches its own
-	 * instructions.
-	 *
-	 * MAP_PRIVATE means that the page won't be copied until a write is
-	 * done to it.  This allows us to share untouched memory between
-	 * Guests.
-	 */
-	if (mmap(addr, len, PROT_READ|PROT_WRITE,
-		 MAP_FIXED|MAP_PRIVATE, fd, offset) != MAP_FAILED)
-		return;
-
-	/* pread does a seek and a read in one shot: saves a few lines. */
-	r = pread(fd, addr, len, offset);
-	if (r != len)
-		err(1, "Reading offset %lu len %lu gave %zi", offset, len, r);
-}
-
-/*
- * This routine takes an open vmlinux image, which is in ELF, and maps it into
- * the Guest memory.  ELF = Embedded Linking Format, which is the format used
- * by all modern binaries on Linux including the kernel.
- *
- * The ELF headers give *two* addresses: a physical address, and a virtual
- * address.  We use the physical address; the Guest will map itself to the
- * virtual address.
- *
- * We return the starting address.
- */
-static unsigned long map_elf(int elf_fd, const Elf32_Ehdr *ehdr)
-{
-	Elf32_Phdr phdr[ehdr->e_phnum];
-	unsigned int i;
-
-	/*
-	 * Sanity checks on the main ELF header: an x86 executable with a
-	 * reasonable number of correctly-sized program headers.
-	 */
-	if (ehdr->e_type != ET_EXEC
-	    || ehdr->e_machine != EM_386
-	    || ehdr->e_phentsize != sizeof(Elf32_Phdr)
-	    || ehdr->e_phnum < 1 || ehdr->e_phnum > 65536U/sizeof(Elf32_Phdr))
-		errx(1, "Malformed elf header");
-
-	/*
-	 * An ELF executable contains an ELF header and a number of "program"
-	 * headers which indicate which parts ("segments") of the program to
-	 * load where.
-	 */
-
-	/* We read in all the program headers at once: */
-	if (lseek(elf_fd, ehdr->e_phoff, SEEK_SET) < 0)
-		err(1, "Seeking to program headers");
-	if (read(elf_fd, phdr, sizeof(phdr)) != sizeof(phdr))
-		err(1, "Reading program headers");
-
-	/*
-	 * Try all the headers: there are usually only three.  A read-only one,
-	 * a read-write one, and a "note" section which we don't load.
-	 */
-	for (i = 0; i < ehdr->e_phnum; i++) {
-		/* If this isn't a loadable segment, we ignore it */
-		if (phdr[i].p_type != PT_LOAD)
-			continue;
-
-		verbose("Section %i: size %i addr %p\n",
-			i, phdr[i].p_memsz, (void *)phdr[i].p_paddr);
-
-		/* We map this section of the file at its physical address. */
-		map_at(elf_fd, from_guest_phys(phdr[i].p_paddr),
-		       phdr[i].p_offset, phdr[i].p_filesz);
-	}
-
-	/* The entry point is given in the ELF header. */
-	return ehdr->e_entry;
-}
-
-/*L:150
- * A bzImage, unlike an ELF file, is not meant to be loaded.  You're supposed
- * to jump into it and it will unpack itself.  We used to have to perform some
- * hairy magic because the unpacking code scared me.
- *
- * Fortunately, Jeremy Fitzhardinge convinced me it wasn't that hard and wrote
- * a small patch to jump over the tricky bits in the Guest, so now we just read
- * the funky header so we know where in the file to load, and away we go!
- */
-static unsigned long load_bzimage(int fd)
-{
-	struct boot_params boot;
-	int r;
-	/* Modern bzImages get loaded at 1M. */
-	void *p = from_guest_phys(0x100000);
-
-	/*
-	 * Go back to the start of the file and read the header.  It should be
-	 * a Linux boot header (see Documentation/x86/i386/boot.txt)
-	 */
-	lseek(fd, 0, SEEK_SET);
-	read(fd, &boot, sizeof(boot));
-
-	/* Inside the setup_hdr, we expect the magic "HdrS" */
-	if (memcmp(&boot.hdr.header, "HdrS", 4) != 0)
-		errx(1, "This doesn't look like a bzImage to me");
-
-	/* Skip over the extra sectors of the header. */
-	lseek(fd, (boot.hdr.setup_sects+1) * 512, SEEK_SET);
-
-	/* Now read everything into memory. in nice big chunks. */
-	while ((r = read(fd, p, 65536)) > 0)
-		p += r;
-
-	/* Finally, code32_start tells us where to enter the kernel. */
-	return boot.hdr.code32_start;
-}
-
-/*L:140
- * Loading the kernel is easy when it's a "vmlinux", but most kernels
- * come wrapped up in the self-decompressing "bzImage" format.  With a little
- * work, we can load those, too.
- */
-static unsigned long load_kernel(int fd)
-{
-	Elf32_Ehdr hdr;
-
-	/* Read in the first few bytes. */
-	if (read(fd, &hdr, sizeof(hdr)) != sizeof(hdr))
-		err(1, "Reading kernel");
-
-	/* If it's an ELF file, it starts with "\177ELF" */
-	if (memcmp(hdr.e_ident, ELFMAG, SELFMAG) == 0)
-		return map_elf(fd, &hdr);
-
-	/* Otherwise we assume it's a bzImage, and try to load it. */
-	return load_bzimage(fd);
-}
-
-/*
- * This is a trivial little helper to align pages.  Andi Kleen hated it because
- * it calls getpagesize() twice: "it's dumb code."
- *
- * Kernel guys get really het up about optimization, even when it's not
- * necessary.  I leave this code as a reaction against that.
- */
-static inline unsigned long page_align(unsigned long addr)
-{
-	/* Add upwards and truncate downwards. */
-	return ((addr + getpagesize()-1) & ~(getpagesize()-1));
-}
-
-/*L:180
- * An "initial ram disk" is a disk image loaded into memory along with the
- * kernel which the kernel can use to boot from without needing any drivers.
- * Most distributions now use this as standard: the initrd contains the code to
- * load the appropriate driver modules for the current machine.
- *
- * Importantly, James Morris works for RedHat, and Fedora uses initrds for its
- * kernels.  He sent me this (and tells me when I break it).
- */
-static unsigned long load_initrd(const char *name, unsigned long mem)
-{
-	int ifd;
-	struct stat st;
-	unsigned long len;
-
-	ifd = open_or_die(name, O_RDONLY);
-	/* fstat() is needed to get the file size. */
-	if (fstat(ifd, &st) < 0)
-		err(1, "fstat() on initrd '%s'", name);
-
-	/*
-	 * We map the initrd at the top of memory, but mmap wants it to be
-	 * page-aligned, so we round the size up for that.
-	 */
-	len = page_align(st.st_size);
-	map_at(ifd, from_guest_phys(mem - len), 0, st.st_size);
-	/*
-	 * Once a file is mapped, you can close the file descriptor.  It's a
-	 * little odd, but quite useful.
-	 */
-	close(ifd);
-	verbose("mapped initrd %s size=%lu @ %p\n", name, len, (void*)mem-len);
-
-	/* We return the initrd size. */
-	return len;
-}
-/*:*/
-
-/*
- * Simple routine to roll all the commandline arguments together with spaces
- * between them.
- */
-static void concat(char *dst, char *args[])
-{
-	unsigned int i, len = 0;
-
-	for (i = 0; args[i]; i++) {
-		if (i) {
-			strcat(dst+len, " ");
-			len++;
-		}
-		strcpy(dst+len, args[i]);
-		len += strlen(args[i]);
-	}
-	/* In case it's empty. */
-	dst[len] = '\0';
-}
-
-/*L:185
- * This is where we actually tell the kernel to initialize the Guest.  We
- * saw the arguments it expects when we looked at initialize() in lguest_user.c:
- * the base of Guest "physical" memory, the top physical page to allow and the
- * entry point for the Guest.
- */
-static void tell_kernel(unsigned long start)
-{
-	unsigned long args[] = { LHREQ_INITIALIZE,
-				 (unsigned long)guest_base,
-				 guest_limit / getpagesize(), start };
-	verbose("Guest: %p - %p (%#lx)\n",
-		guest_base, guest_base + guest_limit, guest_limit);
-	lguest_fd = open_or_die("/dev/lguest", O_RDWR);
-	if (write(lguest_fd, args, sizeof(args)) < 0)
-		err(1, "Writing to /dev/lguest");
-}
-/*:*/
-
-/*L:200
- * Device Handling.
- *
- * When the Guest gives us a buffer, it sends an array of addresses and sizes.
- * We need to make sure it's not trying to reach into the Launcher itself, so
- * we have a convenient routine which checks it and exits with an error message
- * if something funny is going on:
- */
-static void *_check_pointer(unsigned long addr, unsigned int size,
-			    unsigned int line)
-{
-	/*
-	 * Check if the requested address and size exceeds the allocated memory,
-	 * or addr + size wraps around.
-	 */
-	if ((addr + size) > guest_limit || (addr + size) < addr)
-		errx(1, "%s:%i: Invalid address %#lx", __FILE__, line, addr);
-	/*
-	 * We return a pointer for the caller's convenience, now we know it's
-	 * safe to use.
-	 */
-	return from_guest_phys(addr);
-}
-/* A macro which transparently hands the line number to the real function. */
-#define check_pointer(addr,size) _check_pointer(addr, size, __LINE__)
-
-/*
- * Each buffer in the virtqueues is actually a chain of descriptors.  This
- * function returns the next descriptor in the chain, or vq->vring.num if we're
- * at the end.
- */
-static unsigned next_desc(struct vring_desc *desc,
-			  unsigned int i, unsigned int max)
-{
-	unsigned int next;
-
-	/* If this descriptor says it doesn't chain, we're done. */
-	if (!(desc[i].flags & VRING_DESC_F_NEXT))
-		return max;
-
-	/* Check they're not leading us off end of descriptors. */
-	next = desc[i].next;
-	/* Make sure compiler knows to grab that: we don't want it changing! */
-	wmb();
-
-	if (next >= max)
-		errx(1, "Desc next is %u", next);
-
-	return next;
-}
-
-/*
- * This actually sends the interrupt for this virtqueue, if we've used a
- * buffer.
- */
-static void trigger_irq(struct virtqueue *vq)
-{
-	unsigned long buf[] = { LHREQ_IRQ, vq->config.irq };
-
-	/* Don't inform them if nothing used. */
-	if (!vq->pending_used)
-		return;
-	vq->pending_used = 0;
-
-	/* If they don't want an interrupt, don't send one... */
-	if (vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT) {
-		/* ... unless they've asked us to force one on empty. */
-		if (!vq->dev->irq_on_empty
-		    || lg_last_avail(vq) != vq->vring.avail->idx)
-			return;
-	}
-
-	/* Send the Guest an interrupt tell them we used something up. */
-	if (write(lguest_fd, buf, sizeof(buf)) != 0)
-		err(1, "Triggering irq %i", vq->config.irq);
-}
-
-/*
- * This looks in the virtqueue for the first available buffer, and converts
- * it to an iovec for convenient access.  Since descriptors consist of some
- * number of output then some number of input descriptors, it's actually two
- * iovecs, but we pack them into one and note how many of each there were.
- *
- * This function waits if necessary, and returns the descriptor number found.
- */
-static unsigned wait_for_vq_desc(struct virtqueue *vq,
-				 struct iovec iov[],
-				 unsigned int *out_num, unsigned int *in_num)
-{
-	unsigned int i, head, max;
-	struct vring_desc *desc;
-	u16 last_avail = lg_last_avail(vq);
-
-	/* There's nothing available? */
-	while (last_avail == vq->vring.avail->idx) {
-		u64 event;
-
-		/*
-		 * Since we're about to sleep, now is a good time to tell the
-		 * Guest about what we've used up to now.
-		 */
-		trigger_irq(vq);
-
-		/* OK, now we need to know about added descriptors. */
-		vq->vring.used->flags &= ~VRING_USED_F_NO_NOTIFY;
-
-		/*
-		 * They could have slipped one in as we were doing that: make
-		 * sure it's written, then check again.
-		 */
-		mb();
-		if (last_avail != vq->vring.avail->idx) {
-			vq->vring.used->flags |= VRING_USED_F_NO_NOTIFY;
-			break;
-		}
-
-		/* Nothing new?  Wait for eventfd to tell us they refilled. */
-		if (read(vq->eventfd, &event, sizeof(event)) != sizeof(event))
-			errx(1, "Event read failed?");
-
-		/* We don't need to be notified again. */
-		vq->vring.used->flags |= VRING_USED_F_NO_NOTIFY;
-	}
-
-	/* Check it isn't doing very strange things with descriptor numbers. */
-	if ((u16)(vq->vring.avail->idx - last_avail) > vq->vring.num)
-		errx(1, "Guest moved used index from %u to %u",
-		     last_avail, vq->vring.avail->idx);
-
-	/*
-	 * Grab the next descriptor number they're advertising, and increment
-	 * the index we've seen.
-	 */
-	head = vq->vring.avail->ring[last_avail % vq->vring.num];
-	lg_last_avail(vq)++;
-
-	/* If their number is silly, that's a fatal mistake. */
-	if (head >= vq->vring.num)
-		errx(1, "Guest says index %u is available", head);
-
-	/* When we start there are none of either input nor output. */
-	*out_num = *in_num = 0;
-
-	max = vq->vring.num;
-	desc = vq->vring.desc;
-	i = head;
-
-	/*
-	 * If this is an indirect entry, then this buffer contains a descriptor
-	 * table which we handle as if it's any normal descriptor chain.
-	 */
-	if (desc[i].flags & VRING_DESC_F_INDIRECT) {
-		if (desc[i].len % sizeof(struct vring_desc))
-			errx(1, "Invalid size for indirect buffer table");
-
-		max = desc[i].len / sizeof(struct vring_desc);
-		desc = check_pointer(desc[i].addr, desc[i].len);
-		i = 0;
-	}
-
-	do {
-		/* Grab the first descriptor, and check it's OK. */
-		iov[*out_num + *in_num].iov_len = desc[i].len;
-		iov[*out_num + *in_num].iov_base
-			= check_pointer(desc[i].addr, desc[i].len);
-		/* If this is an input descriptor, increment that count. */
-		if (desc[i].flags & VRING_DESC_F_WRITE)
-			(*in_num)++;
-		else {
-			/*
-			 * If it's an output descriptor, they're all supposed
-			 * to come before any input descriptors.
-			 */
-			if (*in_num)
-				errx(1, "Descriptor has out after in");
-			(*out_num)++;
-		}
-
-		/* If we've got too many, that implies a descriptor loop. */
-		if (*out_num + *in_num > max)
-			errx(1, "Looped descriptor");
-	} while ((i = next_desc(desc, i, max)) != max);
-
-	return head;
-}
-
-/*
- * After we've used one of their buffers, we tell the Guest about it.  Sometime
- * later we'll want to send them an interrupt using trigger_irq(); note that
- * wait_for_vq_desc() does that for us if it has to wait.
- */
-static void add_used(struct virtqueue *vq, unsigned int head, int len)
-{
-	struct vring_used_elem *used;
-
-	/*
-	 * The virtqueue contains a ring of used buffers.  Get a pointer to the
-	 * next entry in that used ring.
-	 */
-	used = &vq->vring.used->ring[vq->vring.used->idx % vq->vring.num];
-	used->id = head;
-	used->len = len;
-	/* Make sure buffer is written before we update index. */
-	wmb();
-	vq->vring.used->idx++;
-	vq->pending_used++;
-}
-
-/* And here's the combo meal deal.  Supersize me! */
-static void add_used_and_trigger(struct virtqueue *vq, unsigned head, int len)
-{
-	add_used(vq, head, len);
-	trigger_irq(vq);
-}
-
-/*
- * The Console
- *
- * We associate some data with the console for our exit hack.
- */
-struct console_abort {
-	/* How many times have they hit ^C? */
-	int count;
-	/* When did they start? */
-	struct timeval start;
-};
-
-/* This is the routine which handles console input (ie. stdin). */
-static void console_input(struct virtqueue *vq)
-{
-	int len;
-	unsigned int head, in_num, out_num;
-	struct console_abort *abort = vq->dev->priv;
-	struct iovec iov[vq->vring.num];
-
-	/* Make sure there's a descriptor available. */
-	head = wait_for_vq_desc(vq, iov, &out_num, &in_num);
-	if (out_num)
-		errx(1, "Output buffers in console in queue?");
-
-	/* Read into it.  This is where we usually wait. */
-	len = readv(STDIN_FILENO, iov, in_num);
-	if (len <= 0) {
-		/* Ran out of input? */
-		warnx("Failed to get console input, ignoring console.");
-		/*
-		 * For simplicity, dying threads kill the whole Launcher.  So
-		 * just nap here.
-		 */
-		for (;;)
-			pause();
-	}
-
-	/* Tell the Guest we used a buffer. */
-	add_used_and_trigger(vq, head, len);
-
-	/*
-	 * Three ^C within one second?  Exit.
-	 *
-	 * This is such a hack, but works surprisingly well.  Each ^C has to
-	 * be in a buffer by itself, so they can't be too fast.  But we check
-	 * that we get three within about a second, so they can't be too
-	 * slow.
-	 */
-	if (len != 1 || ((char *)iov[0].iov_base)[0] != 3) {
-		abort->count = 0;
-		return;
-	}
-
-	abort->count++;
-	if (abort->count == 1)
-		gettimeofday(&abort->start, NULL);
-	else if (abort->count == 3) {
-		struct timeval now;
-		gettimeofday(&now, NULL);
-		/* Kill all Launcher processes with SIGINT, like normal ^C */
-		if (now.tv_sec <= abort->start.tv_sec+1)
-			kill(0, SIGINT);
-		abort->count = 0;
-	}
-}
-
-/* This is the routine which handles console output (ie. stdout). */
-static void console_output(struct virtqueue *vq)
-{
-	unsigned int head, out, in;
-	struct iovec iov[vq->vring.num];
-
-	/* We usually wait in here, for the Guest to give us something. */
-	head = wait_for_vq_desc(vq, iov, &out, &in);
-	if (in)
-		errx(1, "Input buffers in console output queue?");
-
-	/* writev can return a partial write, so we loop here. */
-	while (!iov_empty(iov, out)) {
-		int len = writev(STDOUT_FILENO, iov, out);
-		if (len <= 0)
-			err(1, "Write to stdout gave %i", len);
-		iov_consume(iov, out, len);
-	}
-
-	/*
-	 * We're finished with that buffer: if we're going to sleep,
-	 * wait_for_vq_desc() will prod the Guest with an interrupt.
-	 */
-	add_used(vq, head, 0);
-}
-
-/*
- * The Network
- *
- * Handling output for network is also simple: we get all the output buffers
- * and write them to /dev/net/tun.
- */
-struct net_info {
-	int tunfd;
-};
-
-static void net_output(struct virtqueue *vq)
-{
-	struct net_info *net_info = vq->dev->priv;
-	unsigned int head, out, in;
-	struct iovec iov[vq->vring.num];
-
-	/* We usually wait in here for the Guest to give us a packet. */
-	head = wait_for_vq_desc(vq, iov, &out, &in);
-	if (in)
-		errx(1, "Input buffers in net output queue?");
-	/*
-	 * Send the whole thing through to /dev/net/tun.  It expects the exact
-	 * same format: what a coincidence!
-	 */
-	if (writev(net_info->tunfd, iov, out) < 0)
-		errx(1, "Write to tun failed?");
-
-	/*
-	 * Done with that one; wait_for_vq_desc() will send the interrupt if
-	 * all packets are processed.
-	 */
-	add_used(vq, head, 0);
-}
-
-/*
- * Handling network input is a bit trickier, because I've tried to optimize it.
- *
- * First we have a helper routine which tells is if from this file descriptor
- * (ie. the /dev/net/tun device) will block:
- */
-static bool will_block(int fd)
-{
-	fd_set fdset;
-	struct timeval zero = { 0, 0 };
-	FD_ZERO(&fdset);
-	FD_SET(fd, &fdset);
-	return select(fd+1, &fdset, NULL, NULL, &zero) != 1;
-}
-
-/*
- * This handles packets coming in from the tun device to our Guest.  Like all
- * service routines, it gets called again as soon as it returns, so you don't
- * see a while(1) loop here.
- */
-static void net_input(struct virtqueue *vq)
-{
-	int len;
-	unsigned int head, out, in;
-	struct iovec iov[vq->vring.num];
-	struct net_info *net_info = vq->dev->priv;
-
-	/*
-	 * Get a descriptor to write an incoming packet into.  This will also
-	 * send an interrupt if they're out of descriptors.
-	 */
-	head = wait_for_vq_desc(vq, iov, &out, &in);
-	if (out)
-		errx(1, "Output buffers in net input queue?");
-
-	/*
-	 * If it looks like we'll block reading from the tun device, send them
-	 * an interrupt.
-	 */
-	if (vq->pending_used && will_block(net_info->tunfd))
-		trigger_irq(vq);
-
-	/*
-	 * Read in the packet.  This is where we normally wait (when there's no
-	 * incoming network traffic).
-	 */
-	len = readv(net_info->tunfd, iov, in);
-	if (len <= 0)
-		err(1, "Failed to read from tun.");
-
-	/*
-	 * Mark that packet buffer as used, but don't interrupt here.  We want
-	 * to wait until we've done as much work as we can.
-	 */
-	add_used(vq, head, len);
-}
-/*:*/
-
-/* This is the helper to create threads: run the service routine in a loop. */
-static int do_thread(void *_vq)
-{
-	struct virtqueue *vq = _vq;
-
-	for (;;)
-		vq->service(vq);
-	return 0;
-}
-
-/*
- * When a child dies, we kill our entire process group with SIGTERM.  This
- * also has the side effect that the shell restores the console for us!
- */
-static void kill_launcher(int signal)
-{
-	kill(0, SIGTERM);
-}
-
-static void reset_device(struct device *dev)
-{
-	struct virtqueue *vq;
-
-	verbose("Resetting device %s\n", dev->name);
-
-	/* Clear any features they've acked. */
-	memset(get_feature_bits(dev) + dev->feature_len, 0, dev->feature_len);
-
-	/* We're going to be explicitly killing threads, so ignore them. */
-	signal(SIGCHLD, SIG_IGN);
-
-	/* Zero out the virtqueues, get rid of their threads */
-	for (vq = dev->vq; vq; vq = vq->next) {
-		if (vq->thread != (pid_t)-1) {
-			kill(vq->thread, SIGTERM);
-			waitpid(vq->thread, NULL, 0);
-			vq->thread = (pid_t)-1;
-		}
-		memset(vq->vring.desc, 0,
-		       vring_size(vq->config.num, LGUEST_VRING_ALIGN));
-		lg_last_avail(vq) = 0;
-	}
-	dev->running = false;
-
-	/* Now we care if threads die. */
-	signal(SIGCHLD, (void *)kill_launcher);
-}
-
-/*L:216
- * This actually creates the thread which services the virtqueue for a device.
- */
-static void create_thread(struct virtqueue *vq)
-{
-	/*
-	 * Create stack for thread.  Since the stack grows upwards, we point
-	 * the stack pointer to the end of this region.
-	 */
-	char *stack = malloc(32768);
-	unsigned long args[] = { LHREQ_EVENTFD,
-				 vq->config.pfn*getpagesize(), 0 };
-
-	/* Create a zero-initialized eventfd. */
-	vq->eventfd = eventfd(0, 0);
-	if (vq->eventfd < 0)
-		err(1, "Creating eventfd");
-	args[2] = vq->eventfd;
-
-	/*
-	 * Attach an eventfd to this virtqueue: it will go off when the Guest
-	 * does an LHCALL_NOTIFY for this vq.
-	 */
-	if (write(lguest_fd, &args, sizeof(args)) != 0)
-		err(1, "Attaching eventfd");
-
-	/*
-	 * CLONE_VM: because it has to access the Guest memory, and SIGCHLD so
-	 * we get a signal if it dies.
-	 */
-	vq->thread = clone(do_thread, stack + 32768, CLONE_VM | SIGCHLD, vq);
-	if (vq->thread == (pid_t)-1)
-		err(1, "Creating clone");
-
-	/* We close our local copy now the child has it. */
-	close(vq->eventfd);
-}
-
-static bool accepted_feature(struct device *dev, unsigned int bit)
-{
-	const u8 *features = get_feature_bits(dev) + dev->feature_len;
-
-	if (dev->feature_len < bit / CHAR_BIT)
-		return false;
-	return features[bit / CHAR_BIT] & (1 << (bit % CHAR_BIT));
-}
-
-static void start_device(struct device *dev)
-{
-	unsigned int i;
-	struct virtqueue *vq;
-
-	verbose("Device %s OK: offered", dev->name);
-	for (i = 0; i < dev->feature_len; i++)
-		verbose(" %02x", get_feature_bits(dev)[i]);
-	verbose(", accepted");
-	for (i = 0; i < dev->feature_len; i++)
-		verbose(" %02x", get_feature_bits(dev)
-			[dev->feature_len+i]);
-
-	dev->irq_on_empty = accepted_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY);
-
-	for (vq = dev->vq; vq; vq = vq->next) {
-		if (vq->service)
-			create_thread(vq);
-	}
-	dev->running = true;
-}
-
-static void cleanup_devices(void)
-{
-	struct device *dev;
-
-	for (dev = devices.dev; dev; dev = dev->next)
-		reset_device(dev);
-
-	/* If we saved off the original terminal settings, restore them now. */
-	if (orig_term.c_lflag & (ISIG|ICANON|ECHO))
-		tcsetattr(STDIN_FILENO, TCSANOW, &orig_term);
-}
-
-/* When the Guest tells us they updated the status field, we handle it. */
-static void update_device_status(struct device *dev)
-{
-	/* A zero status is a reset, otherwise it's a set of flags. */
-	if (dev->desc->status == 0)
-		reset_device(dev);
-	else if (dev->desc->status & VIRTIO_CONFIG_S_FAILED) {
-		warnx("Device %s configuration FAILED", dev->name);
-		if (dev->running)
-			reset_device(dev);
-	} else if (dev->desc->status & VIRTIO_CONFIG_S_DRIVER_OK) {
-		if (!dev->running)
-			start_device(dev);
-	}
-}
-
-/*L:215
- * This is the generic routine we call when the Guest uses LHCALL_NOTIFY.  In
- * particular, it's used to notify us of device status changes during boot.
- */
-static void handle_output(unsigned long addr)
-{
-	struct device *i;
-
-	/* Check each device. */
-	for (i = devices.dev; i; i = i->next) {
-		struct virtqueue *vq;
-
-		/*
-		 * Notifications to device descriptors mean they updated the
-		 * device status.
-		 */
-		if (from_guest_phys(addr) == i->desc) {
-			update_device_status(i);
-			return;
-		}
-
-		/*
-		 * Devices *can* be used before status is set to DRIVER_OK.
-		 * The original plan was that they would never do this: they
-		 * would always finish setting up their status bits before
-		 * actually touching the virtqueues.  In practice, we allowed
-		 * them to, and they do (eg. the disk probes for partition
-		 * tables as part of initialization).
-		 *
-		 * If we see this, we start the device: once it's running, we
-		 * expect the device to catch all the notifications.
-		 */
-		for (vq = i->vq; vq; vq = vq->next) {
-			if (addr != vq->config.pfn*getpagesize())
-				continue;
-			if (i->running)
-				errx(1, "Notification on running %s", i->name);
-			/* This just calls create_thread() for each virtqueue */
-			start_device(i);
-			return;
-		}
-	}
-
-	/*
-	 * Early console write is done using notify on a nul-terminated string
-	 * in Guest memory.  It's also great for hacking debugging messages
-	 * into a Guest.
-	 */
-	if (addr >= guest_limit)
-		errx(1, "Bad NOTIFY %#lx", addr);
-
-	write(STDOUT_FILENO, from_guest_phys(addr),
-	      strnlen(from_guest_phys(addr), guest_limit - addr));
-}
-
-/*L:190
- * Device Setup
- *
- * All devices need a descriptor so the Guest knows it exists, and a "struct
- * device" so the Launcher can keep track of it.  We have common helper
- * routines to allocate and manage them.
- */
-
-/*
- * The layout of the device page is a "struct lguest_device_desc" followed by a
- * number of virtqueue descriptors, then two sets of feature bits, then an
- * array of configuration bytes.  This routine returns the configuration
- * pointer.
- */
-static u8 *device_config(const struct device *dev)
-{
-	return (void *)(dev->desc + 1)
-		+ dev->num_vq * sizeof(struct lguest_vqconfig)
-		+ dev->feature_len * 2;
-}
-
-/*
- * This routine allocates a new "struct lguest_device_desc" from descriptor
- * table page just above the Guest's normal memory.  It returns a pointer to
- * that descriptor.
- */
-static struct lguest_device_desc *new_dev_desc(u16 type)
-{
-	struct lguest_device_desc d = { .type = type };
-	void *p;
-
-	/* Figure out where the next device config is, based on the last one. */
-	if (devices.lastdev)
-		p = device_config(devices.lastdev)
-			+ devices.lastdev->desc->config_len;
-	else
-		p = devices.descpage;
-
-	/* We only have one page for all the descriptors. */
-	if (p + sizeof(d) > (void *)devices.descpage + getpagesize())
-		errx(1, "Too many devices");
-
-	/* p might not be aligned, so we memcpy in. */
-	return memcpy(p, &d, sizeof(d));
-}
-
-/*
- * Each device descriptor is followed by the description of its virtqueues.  We
- * specify how many descriptors the virtqueue is to have.
- */
-static void add_virtqueue(struct device *dev, unsigned int num_descs,
-			  void (*service)(struct virtqueue *))
-{
-	unsigned int pages;
-	struct virtqueue **i, *vq = malloc(sizeof(*vq));
-	void *p;
-
-	/* First we need some memory for this virtqueue. */
-	pages = (vring_size(num_descs, LGUEST_VRING_ALIGN) + getpagesize() - 1)
-		/ getpagesize();
-	p = get_pages(pages);
-
-	/* Initialize the virtqueue */
-	vq->next = NULL;
-	vq->last_avail_idx = 0;
-	vq->dev = dev;
-
-	/*
-	 * This is the routine the service thread will run, and its Process ID
-	 * once it's running.
-	 */
-	vq->service = service;
-	vq->thread = (pid_t)-1;
-
-	/* Initialize the configuration. */
-	vq->config.num = num_descs;
-	vq->config.irq = devices.next_irq++;
-	vq->config.pfn = to_guest_phys(p) / getpagesize();
-
-	/* Initialize the vring. */
-	vring_init(&vq->vring, num_descs, p, LGUEST_VRING_ALIGN);
-
-	/*
-	 * Append virtqueue to this device's descriptor.  We use
-	 * device_config() to get the end of the device's current virtqueues;
-	 * we check that we haven't added any config or feature information
-	 * yet, otherwise we'd be overwriting them.
-	 */
-	assert(dev->desc->config_len == 0 && dev->desc->feature_len == 0);
-	memcpy(device_config(dev), &vq->config, sizeof(vq->config));
-	dev->num_vq++;
-	dev->desc->num_vq++;
-
-	verbose("Virtqueue page %#lx\n", to_guest_phys(p));
-
-	/*
-	 * Add to tail of list, so dev->vq is first vq, dev->vq->next is
-	 * second.
-	 */
-	for (i = &dev->vq; *i; i = &(*i)->next);
-	*i = vq;
-}
-
-/*
- * The first half of the feature bitmask is for us to advertise features.  The
- * second half is for the Guest to accept features.
- */
-static void add_feature(struct device *dev, unsigned bit)
-{
-	u8 *features = get_feature_bits(dev);
-
-	/* We can't extend the feature bits once we've added config bytes */
-	if (dev->desc->feature_len <= bit / CHAR_BIT) {
-		assert(dev->desc->config_len == 0);
-		dev->feature_len = dev->desc->feature_len = (bit/CHAR_BIT) + 1;
-	}
-
-	features[bit / CHAR_BIT] |= (1 << (bit % CHAR_BIT));
-}
-
-/*
- * This routine sets the configuration fields for an existing device's
- * descriptor.  It only works for the last device, but that's OK because that's
- * how we use it.
- */
-static void set_config(struct device *dev, unsigned len, const void *conf)
-{
-	/* Check we haven't overflowed our single page. */
-	if (device_config(dev) + len > devices.descpage + getpagesize())
-		errx(1, "Too many devices");
-
-	/* Copy in the config information, and store the length. */
-	memcpy(device_config(dev), conf, len);
-	dev->desc->config_len = len;
-
-	/* Size must fit in config_len field (8 bits)! */
-	assert(dev->desc->config_len == len);
-}
-
-/*
- * This routine does all the creation and setup of a new device, including
- * calling new_dev_desc() to allocate the descriptor and device memory.  We
- * don't actually start the service threads until later.
- *
- * See what I mean about userspace being boring?
- */
-static struct device *new_device(const char *name, u16 type)
-{
-	struct device *dev = malloc(sizeof(*dev));
-
-	/* Now we populate the fields one at a time. */
-	dev->desc = new_dev_desc(type);
-	dev->name = name;
-	dev->vq = NULL;
-	dev->feature_len = 0;
-	dev->num_vq = 0;
-	dev->running = false;
-
-	/*
-	 * Append to device list.  Prepending to a single-linked list is
-	 * easier, but the user expects the devices to be arranged on the bus
-	 * in command-line order.  The first network device on the command line
-	 * is eth0, the first block device /dev/vda, etc.
-	 */
-	if (devices.lastdev)
-		devices.lastdev->next = dev;
-	else
-		devices.dev = dev;
-	devices.lastdev = dev;
-
-	return dev;
-}
-
-/*
- * Our first setup routine is the console.  It's a fairly simple device, but
- * UNIX tty handling makes it uglier than it could be.
- */
-static void setup_console(void)
-{
-	struct device *dev;
-
-	/* If we can save the initial standard input settings... */
-	if (tcgetattr(STDIN_FILENO, &orig_term) == 0) {
-		struct termios term = orig_term;
-		/*
-		 * Then we turn off echo, line buffering and ^C etc: We want a
-		 * raw input stream to the Guest.
-		 */
-		term.c_lflag &= ~(ISIG|ICANON|ECHO);
-		tcsetattr(STDIN_FILENO, TCSANOW, &term);
-	}
-
-	dev = new_device("console", VIRTIO_ID_CONSOLE);
-
-	/* We store the console state in dev->priv, and initialize it. */
-	dev->priv = malloc(sizeof(struct console_abort));
-	((struct console_abort *)dev->priv)->count = 0;
-
-	/*
-	 * The console needs two virtqueues: the input then the output.  When
-	 * they put something the input queue, we make sure we're listening to
-	 * stdin.  When they put something in the output queue, we write it to
-	 * stdout.
-	 */
-	add_virtqueue(dev, VIRTQUEUE_NUM, console_input);
-	add_virtqueue(dev, VIRTQUEUE_NUM, console_output);
-
-	verbose("device %u: console\n", ++devices.device_num);
-}
-/*:*/
-
-/*M:010
- * Inter-guest networking is an interesting area.  Simplest is to have a
- * --sharenet=<name> option which opens or creates a named pipe.  This can be
- * used to send packets to another guest in a 1:1 manner.
- *
- * More sopisticated is to use one of the tools developed for project like UML
- * to do networking.
- *
- * Faster is to do virtio bonding in kernel.  Doing this 1:1 would be
- * completely generic ("here's my vring, attach to your vring") and would work
- * for any traffic.  Of course, namespace and permissions issues need to be
- * dealt with.  A more sophisticated "multi-channel" virtio_net.c could hide
- * multiple inter-guest channels behind one interface, although it would
- * require some manner of hotplugging new virtio channels.
- *
- * Finally, we could implement a virtio network switch in the kernel.
-:*/
-
-static u32 str2ip(const char *ipaddr)
-{
-	unsigned int b[4];
-
-	if (sscanf(ipaddr, "%u.%u.%u.%u", &b[0], &b[1], &b[2], &b[3]) != 4)
-		errx(1, "Failed to parse IP address '%s'", ipaddr);
-	return (b[0] << 24) | (b[1] << 16) | (b[2] << 8) | b[3];
-}
-
-static void str2mac(const char *macaddr, unsigned char mac[6])
-{
-	unsigned int m[6];
-	if (sscanf(macaddr, "%02x:%02x:%02x:%02x:%02x:%02x",
-		   &m[0], &m[1], &m[2], &m[3], &m[4], &m[5]) != 6)
-		errx(1, "Failed to parse mac address '%s'", macaddr);
-	mac[0] = m[0];
-	mac[1] = m[1];
-	mac[2] = m[2];
-	mac[3] = m[3];
-	mac[4] = m[4];
-	mac[5] = m[5];
-}
-
-/*
- * This code is "adapted" from libbridge: it attaches the Host end of the
- * network device to the bridge device specified by the command line.
- *
- * This is yet another James Morris contribution (I'm an IP-level guy, so I
- * dislike bridging), and I just try not to break it.
- */
-static void add_to_bridge(int fd, const char *if_name, const char *br_name)
-{
-	int ifidx;
-	struct ifreq ifr;
-
-	if (!*br_name)
-		errx(1, "must specify bridge name");
-
-	ifidx = if_nametoindex(if_name);
-	if (!ifidx)
-		errx(1, "interface %s does not exist!", if_name);
-
-	strncpy(ifr.ifr_name, br_name, IFNAMSIZ);
-	ifr.ifr_name[IFNAMSIZ-1] = '\0';
-	ifr.ifr_ifindex = ifidx;
-	if (ioctl(fd, SIOCBRADDIF, &ifr) < 0)
-		err(1, "can't add %s to bridge %s", if_name, br_name);
-}
-
-/*
- * This sets up the Host end of the network device with an IP address, brings
- * it up so packets will flow, the copies the MAC address into the hwaddr
- * pointer.
- */
-static void configure_device(int fd, const char *tapif, u32 ipaddr)
-{
-	struct ifreq ifr;
-	struct sockaddr_in sin;
-
-	memset(&ifr, 0, sizeof(ifr));
-	strcpy(ifr.ifr_name, tapif);
-
-	/* Don't read these incantations.  Just cut & paste them like I did! */
-	sin.sin_family = AF_INET;
-	sin.sin_addr.s_addr = htonl(ipaddr);
-	memcpy(&ifr.ifr_addr, &sin, sizeof(sin));
-	if (ioctl(fd, SIOCSIFADDR, &ifr) != 0)
-		err(1, "Setting %s interface address", tapif);
-	ifr.ifr_flags = IFF_UP;
-	if (ioctl(fd, SIOCSIFFLAGS, &ifr) != 0)
-		err(1, "Bringing interface %s up", tapif);
-}
-
-static int get_tun_device(char tapif[IFNAMSIZ])
-{
-	struct ifreq ifr;
-	int netfd;
-
-	/* Start with this zeroed.  Messy but sure. */
-	memset(&ifr, 0, sizeof(ifr));
-
-	/*
-	 * We open the /dev/net/tun device and tell it we want a tap device.  A
-	 * tap device is like a tun device, only somehow different.  To tell
-	 * the truth, I completely blundered my way through this code, but it
-	 * works now!
-	 */
-	netfd = open_or_die("/dev/net/tun", O_RDWR);
-	ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
-	strcpy(ifr.ifr_name, "tap%d");
-	if (ioctl(netfd, TUNSETIFF, &ifr) != 0)
-		err(1, "configuring /dev/net/tun");
-
-	if (ioctl(netfd, TUNSETOFFLOAD,
-		  TUN_F_CSUM|TUN_F_TSO4|TUN_F_TSO6|TUN_F_TSO_ECN) != 0)
-		err(1, "Could not set features for tun device");
-
-	/*
-	 * We don't need checksums calculated for packets coming in this
-	 * device: trust us!
-	 */
-	ioctl(netfd, TUNSETNOCSUM, 1);
-
-	memcpy(tapif, ifr.ifr_name, IFNAMSIZ);
-	return netfd;
-}
-
-/*L:195
- * Our network is a Host<->Guest network.  This can either use bridging or
- * routing, but the principle is the same: it uses the "tun" device to inject
- * packets into the Host as if they came in from a normal network card.  We
- * just shunt packets between the Guest and the tun device.
- */
-static void setup_tun_net(char *arg)
-{
-	struct device *dev;
-	struct net_info *net_info = malloc(sizeof(*net_info));
-	int ipfd;
-	u32 ip = INADDR_ANY;
-	bool bridging = false;
-	char tapif[IFNAMSIZ], *p;
-	struct virtio_net_config conf;
-
-	net_info->tunfd = get_tun_device(tapif);
-
-	/* First we create a new network device. */
-	dev = new_device("net", VIRTIO_ID_NET);
-	dev->priv = net_info;
-
-	/* Network devices need a recv and a send queue, just like console. */
-	add_virtqueue(dev, VIRTQUEUE_NUM, net_input);
-	add_virtqueue(dev, VIRTQUEUE_NUM, net_output);
-
-	/*
-	 * We need a socket to perform the magic network ioctls to bring up the
-	 * tap interface, connect to the bridge etc.  Any socket will do!
-	 */
-	ipfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
-	if (ipfd < 0)
-		err(1, "opening IP socket");
-
-	/* If the command line was --tunnet=bridge:<name> do bridging. */
-	if (!strncmp(BRIDGE_PFX, arg, strlen(BRIDGE_PFX))) {
-		arg += strlen(BRIDGE_PFX);
-		bridging = true;
-	}
-
-	/* A mac address may follow the bridge name or IP address */
-	p = strchr(arg, ':');
-	if (p) {
-		str2mac(p+1, conf.mac);
-		add_feature(dev, VIRTIO_NET_F_MAC);
-		*p = '\0';
-	}
-
-	/* arg is now either an IP address or a bridge name */
-	if (bridging)
-		add_to_bridge(ipfd, tapif, arg);
-	else
-		ip = str2ip(arg);
-
-	/* Set up the tun device. */
-	configure_device(ipfd, tapif, ip);
-
-	add_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY);
-	/* Expect Guest to handle everything except UFO */
-	add_feature(dev, VIRTIO_NET_F_CSUM);
-	add_feature(dev, VIRTIO_NET_F_GUEST_CSUM);
-	add_feature(dev, VIRTIO_NET_F_GUEST_TSO4);
-	add_feature(dev, VIRTIO_NET_F_GUEST_TSO6);
-	add_feature(dev, VIRTIO_NET_F_GUEST_ECN);
-	add_feature(dev, VIRTIO_NET_F_HOST_TSO4);
-	add_feature(dev, VIRTIO_NET_F_HOST_TSO6);
-	add_feature(dev, VIRTIO_NET_F_HOST_ECN);
-	/* We handle indirect ring entries */
-	add_feature(dev, VIRTIO_RING_F_INDIRECT_DESC);
-	set_config(dev, sizeof(conf), &conf);
-
-	/* We don't need the socket any more; setup is done. */
-	close(ipfd);
-
-	devices.device_num++;
-
-	if (bridging)
-		verbose("device %u: tun %s attached to bridge: %s\n",
-			devices.device_num, tapif, arg);
-	else
-		verbose("device %u: tun %s: %s\n",
-			devices.device_num, tapif, arg);
-}
-/*:*/
-
-/* This hangs off device->priv. */
-struct vblk_info {
-	/* The size of the file. */
-	off64_t len;
-
-	/* The file descriptor for the file. */
-	int fd;
-
-};
-
-/*L:210
- * The Disk
- *
- * The disk only has one virtqueue, so it only has one thread.  It is really
- * simple: the Guest asks for a block number and we read or write that position
- * in the file.
- *
- * Before we serviced each virtqueue in a separate thread, that was unacceptably
- * slow: the Guest waits until the read is finished before running anything
- * else, even if it could have been doing useful work.
- *
- * We could have used async I/O, except it's reputed to suck so hard that
- * characters actually go missing from your code when you try to use it.
- */
-static void blk_request(struct virtqueue *vq)
-{
-	struct vblk_info *vblk = vq->dev->priv;
-	unsigned int head, out_num, in_num, wlen;
-	int ret;
-	u8 *in;
-	struct virtio_blk_outhdr *out;
-	struct iovec iov[vq->vring.num];
-	off64_t off;
-
-	/*
-	 * Get the next request, where we normally wait.  It triggers the
-	 * interrupt to acknowledge previously serviced requests (if any).
-	 */
-	head = wait_for_vq_desc(vq, iov, &out_num, &in_num);
-
-	/*
-	 * Every block request should contain at least one output buffer
-	 * (detailing the location on disk and the type of request) and one
-	 * input buffer (to hold the result).
-	 */
-	if (out_num == 0 || in_num == 0)
-		errx(1, "Bad virtblk cmd %u out=%u in=%u",
-		     head, out_num, in_num);
-
-	out = convert(&iov[0], struct virtio_blk_outhdr);
-	in = convert(&iov[out_num+in_num-1], u8);
-	/*
-	 * For historical reasons, block operations are expressed in 512 byte
-	 * "sectors".
-	 */
-	off = out->sector * 512;
-
-	/*
-	 * In general the virtio block driver is allowed to try SCSI commands.
-	 * It'd be nice if we supported eject, for example, but we don't.
-	 */
-	if (out->type & VIRTIO_BLK_T_SCSI_CMD) {
-		fprintf(stderr, "Scsi commands unsupported\n");
-		*in = VIRTIO_BLK_S_UNSUPP;
-		wlen = sizeof(*in);
-	} else if (out->type & VIRTIO_BLK_T_OUT) {
-		/*
-		 * Write
-		 *
-		 * Move to the right location in the block file.  This can fail
-		 * if they try to write past end.
-		 */
-		if (lseek64(vblk->fd, off, SEEK_SET) != off)
-			err(1, "Bad seek to sector %llu", out->sector);
-
-		ret = writev(vblk->fd, iov+1, out_num-1);
-		verbose("WRITE to sector %llu: %i\n", out->sector, ret);
-
-		/*
-		 * Grr... Now we know how long the descriptor they sent was, we
-		 * make sure they didn't try to write over the end of the block
-		 * file (possibly extending it).
-		 */
-		if (ret > 0 && off + ret > vblk->len) {
-			/* Trim it back to the correct length */
-			ftruncate64(vblk->fd, vblk->len);
-			/* Die, bad Guest, die. */
-			errx(1, "Write past end %llu+%u", off, ret);
-		}
-
-		wlen = sizeof(*in);
-		*in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
-	} else if (out->type & VIRTIO_BLK_T_FLUSH) {
-		/* Flush */
-		ret = fdatasync(vblk->fd);
-		verbose("FLUSH fdatasync: %i\n", ret);
-		wlen = sizeof(*in);
-		*in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR);
-	} else {
-		/*
-		 * Read
-		 *
-		 * Move to the right location in the block file.  This can fail
-		 * if they try to read past end.
-		 */
-		if (lseek64(vblk->fd, off, SEEK_SET) != off)
-			err(1, "Bad seek to sector %llu", out->sector);
-
-		ret = readv(vblk->fd, iov+1, in_num-1);
-		verbose("READ from sector %llu: %i\n", out->sector, ret);
-		if (ret >= 0) {
-			wlen = sizeof(*in) + ret;
-			*in = VIRTIO_BLK_S_OK;
-		} else {
-			wlen = sizeof(*in);
-			*in = VIRTIO_BLK_S_IOERR;
-		}
-	}
-
-	/* Finished that request. */
-	add_used(vq, head, wlen);
-}
-
-/*L:198 This actually sets up a virtual block device. */
-static void setup_block_file(const char *filename)
-{
-	struct device *dev;
-	struct vblk_info *vblk;
-	struct virtio_blk_config conf;
-
-	/* Creat the device. */
-	dev = new_device("block", VIRTIO_ID_BLOCK);
-
-	/* The device has one virtqueue, where the Guest places requests. */
-	add_virtqueue(dev, VIRTQUEUE_NUM, blk_request);
-
-	/* Allocate the room for our own bookkeeping */
-	vblk = dev->priv = malloc(sizeof(*vblk));
-
-	/* First we open the file and store the length. */
-	vblk->fd = open_or_die(filename, O_RDWR|O_LARGEFILE);
-	vblk->len = lseek64(vblk->fd, 0, SEEK_END);
-
-	/* We support FLUSH. */
-	add_feature(dev, VIRTIO_BLK_F_FLUSH);
-
-	/* Tell Guest how many sectors this device has. */
-	conf.capacity = cpu_to_le64(vblk->len / 512);
-
-	/*
-	 * Tell Guest not to put in too many descriptors at once: two are used
-	 * for the in and out elements.
-	 */
-	add_feature(dev, VIRTIO_BLK_F_SEG_MAX);
-	conf.seg_max = cpu_to_le32(VIRTQUEUE_NUM - 2);
-
-	/* Don't try to put whole struct: we have 8 bit limit. */
-	set_config(dev, offsetof(struct virtio_blk_config, geometry), &conf);
-
-	verbose("device %u: virtblock %llu sectors\n",
-		++devices.device_num, le64_to_cpu(conf.capacity));
-}
-
-/*L:211
- * Our random number generator device reads from /dev/random into the Guest's
- * input buffers.  The usual case is that the Guest doesn't want random numbers
- * and so has no buffers although /dev/random is still readable, whereas
- * console is the reverse.
- *
- * The same logic applies, however.
- */
-struct rng_info {
-	int rfd;
-};
-
-static void rng_input(struct virtqueue *vq)
-{
-	int len;
-	unsigned int head, in_num, out_num, totlen = 0;
-	struct rng_info *rng_info = vq->dev->priv;
-	struct iovec iov[vq->vring.num];
-
-	/* First we need a buffer from the Guests's virtqueue. */
-	head = wait_for_vq_desc(vq, iov, &out_num, &in_num);
-	if (out_num)
-		errx(1, "Output buffers in rng?");
-
-	/*
-	 * Just like the console write, we loop to cover the whole iovec.
-	 * In this case, short reads actually happen quite a bit.
-	 */
-	while (!iov_empty(iov, in_num)) {
-		len = readv(rng_info->rfd, iov, in_num);
-		if (len <= 0)
-			err(1, "Read from /dev/random gave %i", len);
-		iov_consume(iov, in_num, len);
-		totlen += len;
-	}
-
-	/* Tell the Guest about the new input. */
-	add_used(vq, head, totlen);
-}
-
-/*L:199
- * This creates a "hardware" random number device for the Guest.
- */
-static void setup_rng(void)
-{
-	struct device *dev;
-	struct rng_info *rng_info = malloc(sizeof(*rng_info));
-
-	/* Our device's privat info simply contains the /dev/random fd. */
-	rng_info->rfd = open_or_die("/dev/random", O_RDONLY);
-
-	/* Create the new device. */
-	dev = new_device("rng", VIRTIO_ID_RNG);
-	dev->priv = rng_info;
-
-	/* The device has one virtqueue, where the Guest places inbufs. */
-	add_virtqueue(dev, VIRTQUEUE_NUM, rng_input);
-
-	verbose("device %u: rng\n", devices.device_num++);
-}
-/* That's the end of device setup. */
-
-/*L:230 Reboot is pretty easy: clean up and exec() the Launcher afresh. */
-static void __attribute__((noreturn)) restart_guest(void)
-{
-	unsigned int i;
-
-	/*
-	 * Since we don't track all open fds, we simply close everything beyond
-	 * stderr.
-	 */
-	for (i = 3; i < FD_SETSIZE; i++)
-		close(i);
-
-	/* Reset all the devices (kills all threads). */
-	cleanup_devices();
-
-	execv(main_args[0], main_args);
-	err(1, "Could not exec %s", main_args[0]);
-}
-
-/*L:220
- * Finally we reach the core of the Launcher which runs the Guest, serves
- * its input and output, and finally, lays it to rest.
- */
-static void __attribute__((noreturn)) run_guest(void)
-{
-	for (;;) {
-		unsigned long notify_addr;
-		int readval;
-
-		/* We read from the /dev/lguest device to run the Guest. */
-		readval = pread(lguest_fd, &notify_addr,
-				sizeof(notify_addr), cpu_id);
-
-		/* One unsigned long means the Guest did HCALL_NOTIFY */
-		if (readval == sizeof(notify_addr)) {
-			verbose("Notify on address %#lx\n", notify_addr);
-			handle_output(notify_addr);
-		/* ENOENT means the Guest died.  Reading tells us why. */
-		} else if (errno == ENOENT) {
-			char reason[1024] = { 0 };
-			pread(lguest_fd, reason, sizeof(reason)-1, cpu_id);
-			errx(1, "%s", reason);
-		/* ERESTART means that we need to reboot the guest */
-		} else if (errno == ERESTART) {
-			restart_guest();
-		/* Anything else means a bug or incompatible change. */
-		} else
-			err(1, "Running guest failed");
-	}
-}
-/*L:240
- * This is the end of the Launcher.  The good news: we are over halfway
- * through!  The bad news: the most fiendish part of the code still lies ahead
- * of us.
- *
- * Are you ready?  Take a deep breath and join me in the core of the Host, in
- * "make Host".
-:*/
-
-static struct option opts[] = {
-	{ "verbose", 0, NULL, 'v' },
-	{ "tunnet", 1, NULL, 't' },
-	{ "block", 1, NULL, 'b' },
-	{ "rng", 0, NULL, 'r' },
-	{ "initrd", 1, NULL, 'i' },
-	{ "username", 1, NULL, 'u' },
-	{ "chroot", 1, NULL, 'c' },
-	{ NULL },
-};
-static void usage(void)
-{
-	errx(1, "Usage: lguest [--verbose] "
-	     "[--tunnet=(<ipaddr>:<macaddr>|bridge:<bridgename>:<macaddr>)\n"
-	     "|--block=<filename>|--initrd=<filename>]...\n"
-	     "<mem-in-mb> vmlinux [args...]");
-}
-
-/*L:105 The main routine is where the real work begins: */
-int main(int argc, char *argv[])
-{
-	/* Memory, code startpoint and size of the (optional) initrd. */
-	unsigned long mem = 0, start, initrd_size = 0;
-	/* Two temporaries. */
-	int i, c;
-	/* The boot information for the Guest. */
-	struct boot_params *boot;
-	/* If they specify an initrd file to load. */
-	const char *initrd_name = NULL;
-
-	/* Password structure for initgroups/setres[gu]id */
-	struct passwd *user_details = NULL;
-
-	/* Directory to chroot to */
-	char *chroot_path = NULL;
-
-	/* Save the args: we "reboot" by execing ourselves again. */
-	main_args = argv;
-
-	/*
-	 * First we initialize the device list.  We keep a pointer to the last
-	 * device, and the next interrupt number to use for devices (1:
-	 * remember that 0 is used by the timer).
-	 */
-	devices.lastdev = NULL;
-	devices.next_irq = 1;
-
-	/* We're CPU 0.  In fact, that's the only CPU possible right now. */
-	cpu_id = 0;
-
-	/*
-	 * We need to know how much memory so we can set up the device
-	 * descriptor and memory pages for the devices as we parse the command
-	 * line.  So we quickly look through the arguments to find the amount
-	 * of memory now.
-	 */
-	for (i = 1; i < argc; i++) {
-		if (argv[i][0] != '-') {
-			mem = atoi(argv[i]) * 1024 * 1024;
-			/*
-			 * We start by mapping anonymous pages over all of
-			 * guest-physical memory range.  This fills it with 0,
-			 * and ensures that the Guest won't be killed when it
-			 * tries to access it.
-			 */
-			guest_base = map_zeroed_pages(mem / getpagesize()
-						      + DEVICE_PAGES);
-			guest_limit = mem;
-			guest_max = mem + DEVICE_PAGES*getpagesize();
-			devices.descpage = get_pages(1);
-			break;
-		}
-	}
-
-	/* The options are fairly straight-forward */
-	while ((c = getopt_long(argc, argv, "v", opts, NULL)) != EOF) {
-		switch (c) {
-		case 'v':
-			verbose = true;
-			break;
-		case 't':
-			setup_tun_net(optarg);
-			break;
-		case 'b':
-			setup_block_file(optarg);
-			break;
-		case 'r':
-			setup_rng();
-			break;
-		case 'i':
-			initrd_name = optarg;
-			break;
-		case 'u':
-			user_details = getpwnam(optarg);
-			if (!user_details)
-				err(1, "getpwnam failed, incorrect username?");
-			break;
-		case 'c':
-			chroot_path = optarg;
-			break;
-		default:
-			warnx("Unknown argument %s", argv[optind]);
-			usage();
-		}
-	}
-	/*
-	 * After the other arguments we expect memory and kernel image name,
-	 * followed by command line arguments for the kernel.
-	 */
-	if (optind + 2 > argc)
-		usage();
-
-	verbose("Guest base is at %p\n", guest_base);
-
-	/* We always have a console device */
-	setup_console();
-
-	/* Now we load the kernel */
-	start = load_kernel(open_or_die(argv[optind+1], O_RDONLY));
-
-	/* Boot information is stashed at physical address 0 */
-	boot = from_guest_phys(0);
-
-	/* Map the initrd image if requested (at top of physical memory) */
-	if (initrd_name) {
-		initrd_size = load_initrd(initrd_name, mem);
-		/*
-		 * These are the location in the Linux boot header where the
-		 * start and size of the initrd are expected to be found.
-		 */
-		boot->hdr.ramdisk_image = mem - initrd_size;
-		boot->hdr.ramdisk_size = initrd_size;
-		/* The bootloader type 0xFF means "unknown"; that's OK. */
-		boot->hdr.type_of_loader = 0xFF;
-	}
-
-	/*
-	 * The Linux boot header contains an "E820" memory map: ours is a
-	 * simple, single region.
-	 */
-	boot->e820_entries = 1;
-	boot->e820_map[0] = ((struct e820entry) { 0, mem, E820_RAM });
-	/*
-	 * The boot header contains a command line pointer: we put the command
-	 * line after the boot header.
-	 */
-	boot->hdr.cmd_line_ptr = to_guest_phys(boot + 1);
-	/* We use a simple helper to copy the arguments separated by spaces. */
-	concat((char *)(boot + 1), argv+optind+2);
-
-	/* Boot protocol version: 2.07 supports the fields for lguest. */
-	boot->hdr.version = 0x207;
-
-	/* The hardware_subarch value of "1" tells the Guest it's an lguest. */
-	boot->hdr.hardware_subarch = 1;
-
-	/* Tell the entry path not to try to reload segment registers. */
-	boot->hdr.loadflags |= KEEP_SEGMENTS;
-
-	/*
-	 * We tell the kernel to initialize the Guest: this returns the open
-	 * /dev/lguest file descriptor.
-	 */
-	tell_kernel(start);
-
-	/* Ensure that we terminate if a device-servicing child dies. */
-	signal(SIGCHLD, kill_launcher);
-
-	/* If we exit via err(), this kills all the threads, restores tty. */
-	atexit(cleanup_devices);
-
-	/* If requested, chroot to a directory */
-	if (chroot_path) {
-		if (chroot(chroot_path) != 0)
-			err(1, "chroot(\"%s\") failed", chroot_path);
-
-		if (chdir("/") != 0)
-			err(1, "chdir(\"/\") failed");
-
-		verbose("chroot done\n");
-	}
-
-	/* If requested, drop privileges */
-	if (user_details) {
-		uid_t u;
-		gid_t g;
-
-		u = user_details->pw_uid;
-		g = user_details->pw_gid;
-
-		if (initgroups(user_details->pw_name, g) != 0)
-			err(1, "initgroups failed");
-
-		if (setresgid(g, g, g) != 0)
-			err(1, "setresgid failed");
-
-		if (setresuid(u, u, u) != 0)
-			err(1, "setresuid failed");
-
-		verbose("Dropping privileges completed\n");
-	}
-
-	/* Finally, run the Guest.  This doesn't return. */
-	run_guest();
-}
-/*:*/
-
-/*M:999
- * Mastery is done: you now know everything I do.
- *
- * But surely you have seen code, features and bugs in your wanderings which
- * you now yearn to attack?  That is the real game, and I look forward to you
- * patching and forking lguest into the Your-Name-Here-visor.
- *
- * Farewell, and good coding!
- * Rusty Russell.
- */
diff --git a/Documentation/lguest/lguest.txt b/Documentation/lguest/lguest.txt
deleted file mode 100644
index dad99978a6a8..000000000000
--- a/Documentation/lguest/lguest.txt
+++ /dev/null
@@ -1,128 +0,0 @@
-      __
- (___()'`;  Rusty's Remarkably Unreliable Guide to Lguest
- /,    /`      - or, A Young Coder's Illustrated Hypervisor
- \\"--\\    http://lguest.ozlabs.org
-
-Lguest is designed to be a minimal 32-bit x86 hypervisor for the Linux kernel,
-for Linux developers and users to experiment with virtualization with the
-minimum of complexity.  Nonetheless, it should have sufficient features to
-make it useful for specific tasks, and, of course, you are encouraged to fork
-and enhance it (see drivers/lguest/README).
-
-Features:
-
-- Kernel module which runs in a normal kernel.
-- Simple I/O model for communication.
-- Simple program to create new guests.
-- Logo contains cute puppies: http://lguest.ozlabs.org
-
-Developer features:
-
-- Fun to hack on.
-- No ABI: being tied to a specific kernel anyway, you can change anything.
-- Many opportunities for improvement or feature implementation.
-
-Running Lguest:
-
-- The easiest way to run lguest is to use same kernel as guest and host.
-  You can configure them differently, but usually it's easiest not to.
-
-  You will need to configure your kernel with the following options:
-
-  "General setup":
-     "Prompt for development and/or incomplete code/drivers" = Y
-        (CONFIG_EXPERIMENTAL=y)
-
-  "Processor type and features":
-     "Paravirtualized guest support" = Y
-        "Lguest guest support" = Y
-     "High Memory Support" = off/4GB
-     "Alignment value to which kernel should be aligned" = 0x100000
-        (CONFIG_PARAVIRT=y, CONFIG_LGUEST_GUEST=y, CONFIG_HIGHMEM64G=n and
-         CONFIG_PHYSICAL_ALIGN=0x100000)
-
-  "Device Drivers":
-     "Block devices"
-        "Virtio block driver (EXPERIMENTAL)" = M/Y
-     "Network device support"
-        "Universal TUN/TAP device driver support" = M/Y
-        "Virtio network driver (EXPERIMENTAL)" = M/Y
-           (CONFIG_VIRTIO_BLK=m, CONFIG_VIRTIO_NET=m and CONFIG_TUN=m)
-
-  "Virtualization"
-     "Linux hypervisor example code" = M/Y
-        (CONFIG_LGUEST=m)
-
-- A tool called "lguest" is available in this directory: type "make"
-  to build it.  If you didn't build your kernel in-tree, use "make
-  O=<builddir>".
-
-- Create or find a root disk image.  There are several useful ones
-  around, such as the xm-test tiny root image at
-	  http://xm-test.xensource.com/ramdisks/initrd-1.1-i386.img
-
-  For more serious work, I usually use a distribution ISO image and
-  install it under qemu, then make multiple copies:
-
-	  dd if=/dev/zero of=rootfile bs=1M count=2048
-	  qemu -cdrom image.iso -hda rootfile -net user -net nic -boot d
-
-  Make sure that you install a getty on /dev/hvc0 if you want to log in on the
-  console!
-
-- "modprobe lg" if you built it as a module.
-
-- Run an lguest as root:
-
-      Documentation/lguest/lguest 64 vmlinux --tunnet=192.168.19.1 --block=rootfile root=/dev/vda
-
-   Explanation:
-    64: the amount of memory to use, in MB.
-
-    vmlinux: the kernel image found in the top of your build directory.  You
-       can also use a standard bzImage.
-
-    --tunnet=192.168.19.1: configures a "tap" device for networking with this
-       IP address.
-
-    --block=rootfile: a file or block device which becomes /dev/vda
-       inside the guest.
-
-    root=/dev/vda: this (and anything else on the command line) are
-       kernel boot parameters.
-
-- Configuring networking.  I usually have the host masquerade, using
-  "iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE" and "echo 1 >
-  /proc/sys/net/ipv4/ip_forward".  In this example, I would configure
-  eth0 inside the guest at 192.168.19.2.
-
-  Another method is to bridge the tap device to an external interface
-  using --tunnet=bridge:<bridgename>, and perhaps run dhcp on the guest
-  to obtain an IP address.  The bridge needs to be configured first:
-  this option simply adds the tap interface to it.
-
-  A simple example on my system:
-
-    ifconfig eth0 0.0.0.0
-    brctl addbr lg0
-    ifconfig lg0 up
-    brctl addif lg0 eth0
-    dhclient lg0
-
-  Then use --tunnet=bridge:lg0 when launching the guest.
-
-  See:
-  
-    http://www.linuxfoundation.org/collaborate/workgroups/networking/bridge
-    
-  for general information on how to get bridging to work.
-
-- Random number generation. Using the --rng option will provide a
-  /dev/hwrng in the guest that will read from the host's /dev/random.
-  Use this option in conjunction with rng-tools (see ../hw_random.txt)
-  to provide entropy to the guest kernel's /dev/random.
-
-There is a helpful mailing list at http://ozlabs.org/mailman/listinfo/lguest
-
-Good luck!
-Rusty Russell rusty@rustcorp.com.au.