lguest: move the lguest tool to the tools directory

This is a better location instead of having it in Documentation.

Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (fixed compile)

5 files changed, 0 insertions, 2261 deletions

diff --git a/Documentation/virtual/lguest/.gitignore b/Documentation/virtual/lguest/.gitignore
deleted file mode 100644
index 115587fd5f6..00000000000
--- a/Documentation/virtual/lguest/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-lguest
diff --git a/Documentation/virtual/lguest/Makefile b/Documentation/virtual/lguest/Makefile
deleted file mode 100644
index 0ac34206f7a..00000000000
--- a/Documentation/virtual/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/virtual/lguest/extract b/Documentation/virtual/lguest/extract
deleted file mode 100644
index 7730bb6e4b9..00000000000
--- a/Documentation/virtual/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/virtual/lguest/lguest.c b/Documentation/virtual/lguest/lguest.c
deleted file mode 100644
index c095d79cae7..00000000000
--- a/Documentation/virtual/lguest/lguest.c
+++ /dev/null
@@ -1,2065 +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 43 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 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;
-
-	/* 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/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) {
-		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) {
-			warn("Write to stdout gave %i (%d)", len, errno);
-			break;
-		}
-		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)
-		warnx("Write to tun failed (%d)?", errno);
-
-	/*
-	 * 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)
-		warn("Failed to read from tun (%d).", errno);
-
-	/*
-	 * 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;