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1/*P:400
2 * This contains run_guest() which actually calls into the Host<->Guest
3 * Switcher and analyzes the return, such as determining if the Guest wants the
4 * Host to do something. This file also contains useful helper routines.
5:*/
6#include <linux/module.h>
7#include <linux/stringify.h>
8#include <linux/stddef.h>
9#include <linux/io.h>
10#include <linux/mm.h>
11#include <linux/vmalloc.h>
12#include <linux/cpu.h>
13#include <linux/freezer.h>
14#include <linux/highmem.h>
15#include <linux/slab.h>
16#include <asm/paravirt.h>
17#include <asm/pgtable.h>
18#include <asm/uaccess.h>
19#include <asm/poll.h>
20#include <asm/asm-offsets.h>
21#include "lg.h"
22
23
24static struct vm_struct *switcher_vma;
25static struct page **switcher_page;
26
27/* This One Big lock protects all inter-guest data structures. */
28DEFINE_MUTEX(lguest_lock);
29
30/*H:010
31 * We need to set up the Switcher at a high virtual address. Remember the
32 * Switcher is a few hundred bytes of assembler code which actually changes the
33 * CPU to run the Guest, and then changes back to the Host when a trap or
34 * interrupt happens.
35 *
36 * The Switcher code must be at the same virtual address in the Guest as the
37 * Host since it will be running as the switchover occurs.
38 *
39 * Trying to map memory at a particular address is an unusual thing to do, so
40 * it's not a simple one-liner.
41 */
42static __init int map_switcher(void)
43{
44 int i, err;
45 struct page **pagep;
46
47 /*
48 * Map the Switcher in to high memory.
49 *
50 * It turns out that if we choose the address 0xFFC00000 (4MB under the
51 * top virtual address), it makes setting up the page tables really
52 * easy.
53 */
54
55 /*
56 * We allocate an array of struct page pointers. map_vm_area() wants
57 * this, rather than just an array of pages.
58 */
59 switcher_page = kmalloc(sizeof(switcher_page[0])*TOTAL_SWITCHER_PAGES,
60 GFP_KERNEL);
61 if (!switcher_page) {
62 err = -ENOMEM;
63 goto out;
64 }
65
66 /*
67 * Now we actually allocate the pages. The Guest will see these pages,
68 * so we make sure they're zeroed.
69 */
70 for (i = 0; i < TOTAL_SWITCHER_PAGES; i++) {
71 switcher_page[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
72 if (!switcher_page[i]) {
73 err = -ENOMEM;
74 goto free_some_pages;
75 }
76 }
77
78 /*
79 * First we check that the Switcher won't overlap the fixmap area at
80 * the top of memory. It's currently nowhere near, but it could have
81 * very strange effects if it ever happened.
82 */
83 if (SWITCHER_ADDR + (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE > FIXADDR_START){
84 err = -ENOMEM;
85 printk("lguest: mapping switcher would thwack fixmap\n");
86 goto free_pages;
87 }
88
89 /*
90 * Now we reserve the "virtual memory area" we want: 0xFFC00000
91 * (SWITCHER_ADDR). We might not get it in theory, but in practice
92 * it's worked so far. The end address needs +1 because __get_vm_area
93 * allocates an extra guard page, so we need space for that.
94 */
95 switcher_vma = __get_vm_area(TOTAL_SWITCHER_PAGES * PAGE_SIZE,
96 VM_ALLOC, SWITCHER_ADDR, SWITCHER_ADDR
97 + (TOTAL_SWITCHER_PAGES+1) * PAGE_SIZE);
98 if (!switcher_vma) {
99 err = -ENOMEM;
100 printk("lguest: could not map switcher pages high\n");
101 goto free_pages;
102 }
103
104 /*
105 * This code actually sets up the pages we've allocated to appear at
106 * SWITCHER_ADDR. map_vm_area() takes the vma we allocated above, the
107 * kind of pages we're mapping (kernel pages), and a pointer to our
108 * array of struct pages. It increments that pointer, but we don't
109 * care.
110 */
111 pagep = switcher_page;
112 err = map_vm_area(switcher_vma, PAGE_KERNEL_EXEC, &pagep);
113 if (err) {
114 printk("lguest: map_vm_area failed: %i\n", err);
115 goto free_vma;
116 }
117
118 /*
119 * Now the Switcher is mapped at the right address, we can't fail!
120 * Copy in the compiled-in Switcher code (from x86/switcher_32.S).
121 */
122 memcpy(switcher_vma->addr, start_switcher_text,
123 end_switcher_text - start_switcher_text);
124
125 printk(KERN_INFO "lguest: mapped switcher at %p\n",
126 switcher_vma->addr);
127 /* And we succeeded... */
128 return 0;
129
130free_vma:
131 vunmap(switcher_vma->addr);
132free_pages:
133 i = TOTAL_SWITCHER_PAGES;
134free_some_pages:
135 for (--i; i >= 0; i--)
136 __free_pages(switcher_page[i], 0);
137 kfree(switcher_page);
138out:
139 return err;
140}
141/*:*/
142
143/* Cleaning up the mapping when the module is unloaded is almost... too easy. */
144static void unmap_switcher(void)
145{
146 unsigned int i;
147
148 /* vunmap() undoes *both* map_vm_area() and __get_vm_area(). */
149 vunmap(switcher_vma->addr);
150 /* Now we just need to free the pages we copied the switcher into */
151 for (i = 0; i < TOTAL_SWITCHER_PAGES; i++)
152 __free_pages(switcher_page[i], 0);
153 kfree(switcher_page);
154}
155
156/*H:032
157 * Dealing With Guest Memory.
158 *
159 * Before we go too much further into the Host, we need to grok the routines
160 * we use to deal with Guest memory.
161 *
162 * When the Guest gives us (what it thinks is) a physical address, we can use
163 * the normal copy_from_user() & copy_to_user() on the corresponding place in
164 * the memory region allocated by the Launcher.
165 *
166 * But we can't trust the Guest: it might be trying to access the Launcher
167 * code. We have to check that the range is below the pfn_limit the Launcher
168 * gave us. We have to make sure that addr + len doesn't give us a false
169 * positive by overflowing, too.
170 */
171bool lguest_address_ok(const struct lguest *lg,
172 unsigned long addr, unsigned long len)
173{
174 return (addr+len) / PAGE_SIZE < lg->pfn_limit && (addr+len >= addr);
175}
176
177/*
178 * This routine copies memory from the Guest. Here we can see how useful the
179 * kill_lguest() routine we met in the Launcher can be: we return a random
180 * value (all zeroes) instead of needing to return an error.
181 */
182void __lgread(struct lg_cpu *cpu, void *b, unsigned long addr, unsigned bytes)
183{
184 if (!lguest_address_ok(cpu->lg, addr, bytes)
185 || copy_from_user(b, cpu->lg->mem_base + addr, bytes) != 0) {
186 /* copy_from_user should do this, but as we rely on it... */
187 memset(b, 0, bytes);
188 kill_guest(cpu, "bad read address %#lx len %u", addr, bytes);
189 }
190}
191
192/* This is the write (copy into Guest) version. */
193void __lgwrite(struct lg_cpu *cpu, unsigned long addr, const void *b,
194 unsigned bytes)
195{
196 if (!lguest_address_ok(cpu->lg, addr, bytes)
197 || copy_to_user(cpu->lg->mem_base + addr, b, bytes) != 0)
198 kill_guest(cpu, "bad write address %#lx len %u", addr, bytes);
199}
200/*:*/
201
202/*H:030
203 * Let's jump straight to the the main loop which runs the Guest.
204 * Remember, this is called by the Launcher reading /dev/lguest, and we keep
205 * going around and around until something interesting happens.
206 */
207int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
208{
209 /* We stop running once the Guest is dead. */
210 while (!cpu->lg->dead) {
211 unsigned int irq;
212 bool more;
213
214 /* First we run any hypercalls the Guest wants done. */
215 if (cpu->hcall)
216 do_hypercalls(cpu);
217
218 /*
219 * It's possible the Guest did a NOTIFY hypercall to the
220 * Launcher.
221 */
222 if (cpu->pending_notify) {
223 /*
224 * Does it just needs to write to a registered
225 * eventfd (ie. the appropriate virtqueue thread)?
226 */
227 if (!send_notify_to_eventfd(cpu)) {
228 /* OK, we tell the main Laucher. */
229 if (put_user(cpu->pending_notify, user))
230 return -EFAULT;
231 return sizeof(cpu->pending_notify);
232 }
233 }
234
235 /* Check for signals */
236 if (signal_pending(current))
237 return -ERESTARTSYS;
238
239 /*
240 * Check if there are any interrupts which can be delivered now:
241 * if so, this sets up the hander to be executed when we next
242 * run the Guest.
243 */
244 irq = interrupt_pending(cpu, &more);
245 if (irq < LGUEST_IRQS)
246 try_deliver_interrupt(cpu, irq, more);
247
248 /*
249 * All long-lived kernel loops need to check with this horrible
250 * thing called the freezer. If the Host is trying to suspend,
251 * it stops us.
252 */
253 try_to_freeze();
254
255 /*
256 * Just make absolutely sure the Guest is still alive. One of
257 * those hypercalls could have been fatal, for example.
258 */
259 if (cpu->lg->dead)
260 break;
261
262 /*
263 * If the Guest asked to be stopped, we sleep. The Guest's
264 * clock timer will wake us.
265 */
266 if (cpu->halted) {
267 set_current_state(TASK_INTERRUPTIBLE);
268 /*
269 * Just before we sleep, make sure no interrupt snuck in
270 * which we should be doing.
271 */
272 if (interrupt_pending(cpu, &more) < LGUEST_IRQS)
273 set_current_state(TASK_RUNNING);
274 else
275 schedule();
276 continue;
277 }
278
279 /*
280 * OK, now we're ready to jump into the Guest. First we put up
281 * the "Do Not Disturb" sign:
282 */
283 local_irq_disable();
284
285 /* Actually run the Guest until something happens. */
286 lguest_arch_run_guest(cpu);
287
288 /* Now we're ready to be interrupted or moved to other CPUs */
289 local_irq_enable();
290
291 /* Now we deal with whatever happened to the Guest. */
292 lguest_arch_handle_trap(cpu);
293 }
294
295 /* Special case: Guest is 'dead' but wants a reboot. */
296 if (cpu->lg->dead == ERR_PTR(-ERESTART))
297 return -ERESTART;
298
299 /* The Guest is dead => "No such file or directory" */
300 return -ENOENT;
301}
302
303/*H:000
304 * Welcome to the Host!
305 *
306 * By this point your brain has been tickled by the Guest code and numbed by
307 * the Launcher code; prepare for it to be stretched by the Host code. This is
308 * the heart. Let's begin at the initialization routine for the Host's lg
309 * module.
310 */
311static int __init init(void)
312{
313 int err;
314
315 /* Lguest can't run under Xen, VMI or itself. It does Tricky Stuff. */
316 if (paravirt_enabled()) {
317 printk("lguest is afraid of being a guest\n");
318 return -EPERM;
319 }
320
321 /* First we put the Switcher up in very high virtual memory. */
322 err = map_switcher();
323 if (err)
324 goto out;
325
326 /* Now we set up the pagetable implementation for the Guests. */
327 err = init_pagetables(switcher_page, SHARED_SWITCHER_PAGES);
328 if (err)
329 goto unmap;
330
331 /* We might need to reserve an interrupt vector. */
332 err = init_interrupts();
333 if (err)
334 goto free_pgtables;
335
336 /* /dev/lguest needs to be registered. */
337 err = lguest_device_init();
338 if (err)
339 goto free_interrupts;
340
341 /* Finally we do some architecture-specific setup. */
342 lguest_arch_host_init();
343
344 /* All good! */
345 return 0;
346
347free_interrupts:
348 free_interrupts();
349free_pgtables:
350 free_pagetables();
351unmap:
352 unmap_switcher();
353out:
354 return err;
355}
356
357/* Cleaning up is just the same code, backwards. With a little French. */
358static void __exit fini(void)
359{
360 lguest_device_remove();
361 free_interrupts();
362 free_pagetables();
363 unmap_switcher();
364
365 lguest_arch_host_fini();
366}
367/*:*/
368
369/*
370 * The Host side of lguest can be a module. This is a nice way for people to
371 * play with it.
372 */
373module_init(init);
374module_exit(fini);
375MODULE_LICENSE("GPL");
376MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
1/*P:400
2 * This contains run_guest() which actually calls into the Host<->Guest
3 * Switcher and analyzes the return, such as determining if the Guest wants the
4 * Host to do something. This file also contains useful helper routines.
5:*/
6#include <linux/module.h>
7#include <linux/stringify.h>
8#include <linux/stddef.h>
9#include <linux/io.h>
10#include <linux/mm.h>
11#include <linux/vmalloc.h>
12#include <linux/cpu.h>
13#include <linux/freezer.h>
14#include <linux/highmem.h>
15#include <linux/slab.h>
16#include <asm/paravirt.h>
17#include <asm/pgtable.h>
18#include <asm/uaccess.h>
19#include <asm/poll.h>
20#include <asm/asm-offsets.h>
21#include "lg.h"
22
23unsigned long switcher_addr;
24struct page **lg_switcher_pages;
25static struct vm_struct *switcher_vma;
26
27/* This One Big lock protects all inter-guest data structures. */
28DEFINE_MUTEX(lguest_lock);
29
30/*H:010
31 * We need to set up the Switcher at a high virtual address. Remember the
32 * Switcher is a few hundred bytes of assembler code which actually changes the
33 * CPU to run the Guest, and then changes back to the Host when a trap or
34 * interrupt happens.
35 *
36 * The Switcher code must be at the same virtual address in the Guest as the
37 * Host since it will be running as the switchover occurs.
38 *
39 * Trying to map memory at a particular address is an unusual thing to do, so
40 * it's not a simple one-liner.
41 */
42static __init int map_switcher(void)
43{
44 int i, err;
45 struct page **pagep;
46
47 /*
48 * Map the Switcher in to high memory.
49 *
50 * It turns out that if we choose the address 0xFFC00000 (4MB under the
51 * top virtual address), it makes setting up the page tables really
52 * easy.
53 */
54
55 /* We assume Switcher text fits into a single page. */
56 if (end_switcher_text - start_switcher_text > PAGE_SIZE) {
57 printk(KERN_ERR "lguest: switcher text too large (%zu)\n",
58 end_switcher_text - start_switcher_text);
59 return -EINVAL;
60 }
61
62 /*
63 * We allocate an array of struct page pointers. map_vm_area() wants
64 * this, rather than just an array of pages.
65 */
66 lg_switcher_pages = kmalloc(sizeof(lg_switcher_pages[0])
67 * TOTAL_SWITCHER_PAGES,
68 GFP_KERNEL);
69 if (!lg_switcher_pages) {
70 err = -ENOMEM;
71 goto out;
72 }
73
74 /*
75 * Now we actually allocate the pages. The Guest will see these pages,
76 * so we make sure they're zeroed.
77 */
78 for (i = 0; i < TOTAL_SWITCHER_PAGES; i++) {
79 lg_switcher_pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
80 if (!lg_switcher_pages[i]) {
81 err = -ENOMEM;
82 goto free_some_pages;
83 }
84 }
85
86 /*
87 * We place the Switcher underneath the fixmap area, which is the
88 * highest virtual address we can get. This is important, since we
89 * tell the Guest it can't access this memory, so we want its ceiling
90 * as high as possible.
91 */
92 switcher_addr = FIXADDR_START - (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE;
93
94 /*
95 * Now we reserve the "virtual memory area" we want. We might
96 * not get it in theory, but in practice it's worked so far.
97 * The end address needs +1 because __get_vm_area allocates an
98 * extra guard page, so we need space for that.
99 */
100 switcher_vma = __get_vm_area(TOTAL_SWITCHER_PAGES * PAGE_SIZE,
101 VM_ALLOC, switcher_addr, switcher_addr
102 + (TOTAL_SWITCHER_PAGES+1) * PAGE_SIZE);
103 if (!switcher_vma) {
104 err = -ENOMEM;
105 printk("lguest: could not map switcher pages high\n");
106 goto free_pages;
107 }
108
109 /*
110 * This code actually sets up the pages we've allocated to appear at
111 * switcher_addr. map_vm_area() takes the vma we allocated above, the
112 * kind of pages we're mapping (kernel pages), and a pointer to our
113 * array of struct pages. It increments that pointer, but we don't
114 * care.
115 */
116 pagep = lg_switcher_pages;
117 err = map_vm_area(switcher_vma, PAGE_KERNEL_EXEC, &pagep);
118 if (err) {
119 printk("lguest: map_vm_area failed: %i\n", err);
120 goto free_vma;
121 }
122
123 /*
124 * Now the Switcher is mapped at the right address, we can't fail!
125 * Copy in the compiled-in Switcher code (from x86/switcher_32.S).
126 */
127 memcpy(switcher_vma->addr, start_switcher_text,
128 end_switcher_text - start_switcher_text);
129
130 printk(KERN_INFO "lguest: mapped switcher at %p\n",
131 switcher_vma->addr);
132 /* And we succeeded... */
133 return 0;
134
135free_vma:
136 vunmap(switcher_vma->addr);
137free_pages:
138 i = TOTAL_SWITCHER_PAGES;
139free_some_pages:
140 for (--i; i >= 0; i--)
141 __free_pages(lg_switcher_pages[i], 0);
142 kfree(lg_switcher_pages);
143out:
144 return err;
145}
146/*:*/
147
148/* Cleaning up the mapping when the module is unloaded is almost... too easy. */
149static void unmap_switcher(void)
150{
151 unsigned int i;
152
153 /* vunmap() undoes *both* map_vm_area() and __get_vm_area(). */
154 vunmap(switcher_vma->addr);
155 /* Now we just need to free the pages we copied the switcher into */
156 for (i = 0; i < TOTAL_SWITCHER_PAGES; i++)
157 __free_pages(lg_switcher_pages[i], 0);
158 kfree(lg_switcher_pages);
159}
160
161/*H:032
162 * Dealing With Guest Memory.
163 *
164 * Before we go too much further into the Host, we need to grok the routines
165 * we use to deal with Guest memory.
166 *
167 * When the Guest gives us (what it thinks is) a physical address, we can use
168 * the normal copy_from_user() & copy_to_user() on the corresponding place in
169 * the memory region allocated by the Launcher.
170 *
171 * But we can't trust the Guest: it might be trying to access the Launcher
172 * code. We have to check that the range is below the pfn_limit the Launcher
173 * gave us. We have to make sure that addr + len doesn't give us a false
174 * positive by overflowing, too.
175 */
176bool lguest_address_ok(const struct lguest *lg,
177 unsigned long addr, unsigned long len)
178{
179 return (addr+len) / PAGE_SIZE < lg->pfn_limit && (addr+len >= addr);
180}
181
182/*
183 * This routine copies memory from the Guest. Here we can see how useful the
184 * kill_lguest() routine we met in the Launcher can be: we return a random
185 * value (all zeroes) instead of needing to return an error.
186 */
187void __lgread(struct lg_cpu *cpu, void *b, unsigned long addr, unsigned bytes)
188{
189 if (!lguest_address_ok(cpu->lg, addr, bytes)
190 || copy_from_user(b, cpu->lg->mem_base + addr, bytes) != 0) {
191 /* copy_from_user should do this, but as we rely on it... */
192 memset(b, 0, bytes);
193 kill_guest(cpu, "bad read address %#lx len %u", addr, bytes);
194 }
195}
196
197/* This is the write (copy into Guest) version. */
198void __lgwrite(struct lg_cpu *cpu, unsigned long addr, const void *b,
199 unsigned bytes)
200{
201 if (!lguest_address_ok(cpu->lg, addr, bytes)
202 || copy_to_user(cpu->lg->mem_base + addr, b, bytes) != 0)
203 kill_guest(cpu, "bad write address %#lx len %u", addr, bytes);
204}
205/*:*/
206
207/*H:030
208 * Let's jump straight to the the main loop which runs the Guest.
209 * Remember, this is called by the Launcher reading /dev/lguest, and we keep
210 * going around and around until something interesting happens.
211 */
212int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
213{
214 /* We stop running once the Guest is dead. */
215 while (!cpu->lg->dead) {
216 unsigned int irq;
217 bool more;
218
219 /* First we run any hypercalls the Guest wants done. */
220 if (cpu->hcall)
221 do_hypercalls(cpu);
222
223 /*
224 * It's possible the Guest did a NOTIFY hypercall to the
225 * Launcher.
226 */
227 if (cpu->pending_notify) {
228 /*
229 * Does it just needs to write to a registered
230 * eventfd (ie. the appropriate virtqueue thread)?
231 */
232 if (!send_notify_to_eventfd(cpu)) {
233 /* OK, we tell the main Launcher. */
234 if (put_user(cpu->pending_notify, user))
235 return -EFAULT;
236 return sizeof(cpu->pending_notify);
237 }
238 }
239
240 /*
241 * All long-lived kernel loops need to check with this horrible
242 * thing called the freezer. If the Host is trying to suspend,
243 * it stops us.
244 */
245 try_to_freeze();
246
247 /* Check for signals */
248 if (signal_pending(current))
249 return -ERESTARTSYS;
250
251 /*
252 * Check if there are any interrupts which can be delivered now:
253 * if so, this sets up the hander to be executed when we next
254 * run the Guest.
255 */
256 irq = interrupt_pending(cpu, &more);
257 if (irq < LGUEST_IRQS)
258 try_deliver_interrupt(cpu, irq, more);
259
260 /*
261 * Just make absolutely sure the Guest is still alive. One of
262 * those hypercalls could have been fatal, for example.
263 */
264 if (cpu->lg->dead)
265 break;
266
267 /*
268 * If the Guest asked to be stopped, we sleep. The Guest's
269 * clock timer will wake us.
270 */
271 if (cpu->halted) {
272 set_current_state(TASK_INTERRUPTIBLE);
273 /*
274 * Just before we sleep, make sure no interrupt snuck in
275 * which we should be doing.
276 */
277 if (interrupt_pending(cpu, &more) < LGUEST_IRQS)
278 set_current_state(TASK_RUNNING);
279 else
280 schedule();
281 continue;
282 }
283
284 /*
285 * OK, now we're ready to jump into the Guest. First we put up
286 * the "Do Not Disturb" sign:
287 */
288 local_irq_disable();
289
290 /* Actually run the Guest until something happens. */
291 lguest_arch_run_guest(cpu);
292
293 /* Now we're ready to be interrupted or moved to other CPUs */
294 local_irq_enable();
295
296 /* Now we deal with whatever happened to the Guest. */
297 lguest_arch_handle_trap(cpu);
298 }
299
300 /* Special case: Guest is 'dead' but wants a reboot. */
301 if (cpu->lg->dead == ERR_PTR(-ERESTART))
302 return -ERESTART;
303
304 /* The Guest is dead => "No such file or directory" */
305 return -ENOENT;
306}
307
308/*H:000
309 * Welcome to the Host!
310 *
311 * By this point your brain has been tickled by the Guest code and numbed by
312 * the Launcher code; prepare for it to be stretched by the Host code. This is
313 * the heart. Let's begin at the initialization routine for the Host's lg
314 * module.
315 */
316static int __init init(void)
317{
318 int err;
319
320 /* Lguest can't run under Xen, VMI or itself. It does Tricky Stuff. */
321 if (get_kernel_rpl() != 0) {
322 printk("lguest is afraid of being a guest\n");
323 return -EPERM;
324 }
325
326 /* First we put the Switcher up in very high virtual memory. */
327 err = map_switcher();
328 if (err)
329 goto out;
330
331 /* We might need to reserve an interrupt vector. */
332 err = init_interrupts();
333 if (err)
334 goto unmap;
335
336 /* /dev/lguest needs to be registered. */
337 err = lguest_device_init();
338 if (err)
339 goto free_interrupts;
340
341 /* Finally we do some architecture-specific setup. */
342 lguest_arch_host_init();
343
344 /* All good! */
345 return 0;
346
347free_interrupts:
348 free_interrupts();
349unmap:
350 unmap_switcher();
351out:
352 return err;
353}
354
355/* Cleaning up is just the same code, backwards. With a little French. */
356static void __exit fini(void)
357{
358 lguest_device_remove();
359 free_interrupts();
360 unmap_switcher();
361
362 lguest_arch_host_fini();
363}
364/*:*/
365
366/*
367 * The Host side of lguest can be a module. This is a nice way for people to
368 * play with it.
369 */
370module_init(init);
371module_exit(fini);
372MODULE_LICENSE("GPL");
373MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");