Commit | Line | Data |
---|---|---|
1c5de193 JF |
1 | /****************************************************************************** |
2 | * privcmd.c | |
3 | * | |
4 | * Interface to privileged domain-0 commands. | |
5 | * | |
6 | * Copyright (c) 2002-2004, K A Fraser, B Dragovic | |
7 | */ | |
8 | ||
283c0972 JP |
9 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt |
10 | ||
1c5de193 | 11 | #include <linux/kernel.h> |
d8414d3c | 12 | #include <linux/module.h> |
1c5de193 JF |
13 | #include <linux/sched.h> |
14 | #include <linux/slab.h> | |
15 | #include <linux/string.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/mm.h> | |
18 | #include <linux/mman.h> | |
19 | #include <linux/uaccess.h> | |
20 | #include <linux/swap.h> | |
1c5de193 JF |
21 | #include <linux/highmem.h> |
22 | #include <linux/pagemap.h> | |
23 | #include <linux/seq_file.h> | |
d8414d3c | 24 | #include <linux/miscdevice.h> |
1c5de193 JF |
25 | |
26 | #include <asm/pgalloc.h> | |
27 | #include <asm/pgtable.h> | |
28 | #include <asm/tlb.h> | |
29 | #include <asm/xen/hypervisor.h> | |
30 | #include <asm/xen/hypercall.h> | |
31 | ||
32 | #include <xen/xen.h> | |
33 | #include <xen/privcmd.h> | |
34 | #include <xen/interface/xen.h> | |
35 | #include <xen/features.h> | |
36 | #include <xen/page.h> | |
de1ef206 | 37 | #include <xen/xen-ops.h> |
d71f5139 | 38 | #include <xen/balloon.h> |
f020e290 | 39 | |
d8414d3c BB |
40 | #include "privcmd.h" |
41 | ||
42 | MODULE_LICENSE("GPL"); | |
43 | ||
d71f5139 MR |
44 | #define PRIV_VMA_LOCKED ((void *)1) |
45 | ||
a5deabe0 ALC |
46 | static int privcmd_vma_range_is_mapped( |
47 | struct vm_area_struct *vma, | |
48 | unsigned long addr, | |
49 | unsigned long nr_pages); | |
1c5de193 | 50 | |
1c5de193 JF |
51 | static long privcmd_ioctl_hypercall(void __user *udata) |
52 | { | |
53 | struct privcmd_hypercall hypercall; | |
54 | long ret; | |
55 | ||
56 | if (copy_from_user(&hypercall, udata, sizeof(hypercall))) | |
57 | return -EFAULT; | |
58 | ||
59 | ret = privcmd_call(hypercall.op, | |
60 | hypercall.arg[0], hypercall.arg[1], | |
61 | hypercall.arg[2], hypercall.arg[3], | |
62 | hypercall.arg[4]); | |
63 | ||
64 | return ret; | |
65 | } | |
66 | ||
67 | static void free_page_list(struct list_head *pages) | |
68 | { | |
69 | struct page *p, *n; | |
70 | ||
71 | list_for_each_entry_safe(p, n, pages, lru) | |
72 | __free_page(p); | |
73 | ||
74 | INIT_LIST_HEAD(pages); | |
75 | } | |
76 | ||
77 | /* | |
78 | * Given an array of items in userspace, return a list of pages | |
79 | * containing the data. If copying fails, either because of memory | |
80 | * allocation failure or a problem reading user memory, return an | |
81 | * error code; its up to the caller to dispose of any partial list. | |
82 | */ | |
83 | static int gather_array(struct list_head *pagelist, | |
84 | unsigned nelem, size_t size, | |
ceb90fa0 | 85 | const void __user *data) |
1c5de193 JF |
86 | { |
87 | unsigned pageidx; | |
88 | void *pagedata; | |
89 | int ret; | |
90 | ||
91 | if (size > PAGE_SIZE) | |
92 | return 0; | |
93 | ||
94 | pageidx = PAGE_SIZE; | |
95 | pagedata = NULL; /* quiet, gcc */ | |
96 | while (nelem--) { | |
97 | if (pageidx > PAGE_SIZE-size) { | |
98 | struct page *page = alloc_page(GFP_KERNEL); | |
99 | ||
100 | ret = -ENOMEM; | |
101 | if (page == NULL) | |
102 | goto fail; | |
103 | ||
104 | pagedata = page_address(page); | |
105 | ||
106 | list_add_tail(&page->lru, pagelist); | |
107 | pageidx = 0; | |
108 | } | |
109 | ||
110 | ret = -EFAULT; | |
111 | if (copy_from_user(pagedata + pageidx, data, size)) | |
112 | goto fail; | |
113 | ||
114 | data += size; | |
115 | pageidx += size; | |
116 | } | |
117 | ||
118 | ret = 0; | |
119 | ||
120 | fail: | |
121 | return ret; | |
122 | } | |
123 | ||
124 | /* | |
125 | * Call function "fn" on each element of the array fragmented | |
126 | * over a list of pages. | |
127 | */ | |
128 | static int traverse_pages(unsigned nelem, size_t size, | |
129 | struct list_head *pos, | |
130 | int (*fn)(void *data, void *state), | |
131 | void *state) | |
132 | { | |
133 | void *pagedata; | |
134 | unsigned pageidx; | |
f020e290 | 135 | int ret = 0; |
1c5de193 JF |
136 | |
137 | BUG_ON(size > PAGE_SIZE); | |
138 | ||
139 | pageidx = PAGE_SIZE; | |
140 | pagedata = NULL; /* hush, gcc */ | |
141 | ||
142 | while (nelem--) { | |
143 | if (pageidx > PAGE_SIZE-size) { | |
144 | struct page *page; | |
145 | pos = pos->next; | |
146 | page = list_entry(pos, struct page, lru); | |
147 | pagedata = page_address(page); | |
148 | pageidx = 0; | |
149 | } | |
150 | ||
151 | ret = (*fn)(pagedata + pageidx, state); | |
152 | if (ret) | |
153 | break; | |
154 | pageidx += size; | |
155 | } | |
156 | ||
157 | return ret; | |
158 | } | |
159 | ||
160 | struct mmap_mfn_state { | |
161 | unsigned long va; | |
162 | struct vm_area_struct *vma; | |
163 | domid_t domain; | |
164 | }; | |
165 | ||
166 | static int mmap_mfn_range(void *data, void *state) | |
167 | { | |
168 | struct privcmd_mmap_entry *msg = data; | |
169 | struct mmap_mfn_state *st = state; | |
170 | struct vm_area_struct *vma = st->vma; | |
171 | int rc; | |
172 | ||
173 | /* Do not allow range to wrap the address space. */ | |
174 | if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) || | |
175 | ((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va)) | |
176 | return -EINVAL; | |
177 | ||
178 | /* Range chunks must be contiguous in va space. */ | |
179 | if ((msg->va != st->va) || | |
180 | ((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end)) | |
181 | return -EINVAL; | |
182 | ||
de1ef206 IC |
183 | rc = xen_remap_domain_mfn_range(vma, |
184 | msg->va & PAGE_MASK, | |
185 | msg->mfn, msg->npages, | |
186 | vma->vm_page_prot, | |
9a032e39 | 187 | st->domain, NULL); |
1c5de193 JF |
188 | if (rc < 0) |
189 | return rc; | |
190 | ||
191 | st->va += msg->npages << PAGE_SHIFT; | |
192 | ||
193 | return 0; | |
194 | } | |
195 | ||
196 | static long privcmd_ioctl_mmap(void __user *udata) | |
197 | { | |
198 | struct privcmd_mmap mmapcmd; | |
199 | struct mm_struct *mm = current->mm; | |
200 | struct vm_area_struct *vma; | |
201 | int rc; | |
202 | LIST_HEAD(pagelist); | |
203 | struct mmap_mfn_state state; | |
204 | ||
d71f5139 MR |
205 | /* We only support privcmd_ioctl_mmap_batch for auto translated. */ |
206 | if (xen_feature(XENFEAT_auto_translated_physmap)) | |
207 | return -ENOSYS; | |
208 | ||
1c5de193 JF |
209 | if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd))) |
210 | return -EFAULT; | |
211 | ||
212 | rc = gather_array(&pagelist, | |
213 | mmapcmd.num, sizeof(struct privcmd_mmap_entry), | |
214 | mmapcmd.entry); | |
215 | ||
216 | if (rc || list_empty(&pagelist)) | |
217 | goto out; | |
218 | ||
219 | down_write(&mm->mmap_sem); | |
220 | ||
221 | { | |
222 | struct page *page = list_first_entry(&pagelist, | |
223 | struct page, lru); | |
224 | struct privcmd_mmap_entry *msg = page_address(page); | |
225 | ||
226 | vma = find_vma(mm, msg->va); | |
227 | rc = -EINVAL; | |
228 | ||
a5deabe0 | 229 | if (!vma || (msg->va != vma->vm_start) || vma->vm_private_data) |
1c5de193 | 230 | goto out_up; |
a5deabe0 | 231 | vma->vm_private_data = PRIV_VMA_LOCKED; |
1c5de193 JF |
232 | } |
233 | ||
234 | state.va = vma->vm_start; | |
235 | state.vma = vma; | |
236 | state.domain = mmapcmd.dom; | |
237 | ||
238 | rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry), | |
239 | &pagelist, | |
240 | mmap_mfn_range, &state); | |
241 | ||
242 | ||
243 | out_up: | |
244 | up_write(&mm->mmap_sem); | |
245 | ||
246 | out: | |
247 | free_page_list(&pagelist); | |
248 | ||
249 | return rc; | |
250 | } | |
251 | ||
252 | struct mmap_batch_state { | |
253 | domid_t domain; | |
254 | unsigned long va; | |
255 | struct vm_area_struct *vma; | |
d71f5139 | 256 | int index; |
ceb90fa0 ALC |
257 | /* A tristate: |
258 | * 0 for no errors | |
259 | * 1 if at least one error has happened (and no | |
260 | * -ENOENT errors have happened) | |
261 | * -ENOENT if at least 1 -ENOENT has happened. | |
262 | */ | |
263 | int global_error; | |
99beae6c | 264 | int version; |
ceb90fa0 ALC |
265 | |
266 | /* User-space mfn array to store errors in the second pass for V1. */ | |
267 | xen_pfn_t __user *user_mfn; | |
99beae6c ALC |
268 | /* User-space int array to store errors in the second pass for V2. */ |
269 | int __user *user_err; | |
1c5de193 JF |
270 | }; |
271 | ||
d71f5139 MR |
272 | /* auto translated dom0 note: if domU being created is PV, then mfn is |
273 | * mfn(addr on bus). If it's auto xlated, then mfn is pfn (input to HAP). | |
274 | */ | |
1c5de193 JF |
275 | static int mmap_batch_fn(void *data, void *state) |
276 | { | |
277 | xen_pfn_t *mfnp = data; | |
278 | struct mmap_batch_state *st = state; | |
d71f5139 MR |
279 | struct vm_area_struct *vma = st->vma; |
280 | struct page **pages = vma->vm_private_data; | |
281 | struct page *cur_page = NULL; | |
ceb90fa0 ALC |
282 | int ret; |
283 | ||
d71f5139 MR |
284 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
285 | cur_page = pages[st->index++]; | |
286 | ||
ceb90fa0 | 287 | ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1, |
9a032e39 | 288 | st->vma->vm_page_prot, st->domain, |
d71f5139 | 289 | &cur_page); |
1c5de193 | 290 | |
ceb90fa0 | 291 | /* Store error code for second pass. */ |
99beae6c ALC |
292 | if (st->version == 1) { |
293 | if (ret < 0) { | |
294 | /* | |
295 | * V1 encodes the error codes in the 32bit top nibble of the | |
296 | * mfn (with its known limitations vis-a-vis 64 bit callers). | |
297 | */ | |
298 | *mfnp |= (ret == -ENOENT) ? | |
299 | PRIVCMD_MMAPBATCH_PAGED_ERROR : | |
300 | PRIVCMD_MMAPBATCH_MFN_ERROR; | |
301 | } | |
302 | } else { /* st->version == 2 */ | |
303 | *((int *) mfnp) = ret; | |
304 | } | |
ceb90fa0 ALC |
305 | |
306 | /* And see if it affects the global_error. */ | |
307 | if (ret < 0) { | |
308 | if (ret == -ENOENT) | |
309 | st->global_error = -ENOENT; | |
310 | else { | |
311 | /* Record that at least one error has happened. */ | |
312 | if (st->global_error == 0) | |
313 | st->global_error = 1; | |
314 | } | |
1c5de193 JF |
315 | } |
316 | st->va += PAGE_SIZE; | |
317 | ||
318 | return 0; | |
319 | } | |
320 | ||
99beae6c | 321 | static int mmap_return_errors(void *data, void *state) |
1c5de193 | 322 | { |
1c5de193 | 323 | struct mmap_batch_state *st = state; |
ceb90fa0 | 324 | |
99beae6c ALC |
325 | if (st->version == 1) { |
326 | xen_pfn_t mfnp = *((xen_pfn_t *) data); | |
327 | if (mfnp & PRIVCMD_MMAPBATCH_MFN_ERROR) | |
328 | return __put_user(mfnp, st->user_mfn++); | |
329 | else | |
330 | st->user_mfn++; | |
331 | } else { /* st->version == 2 */ | |
332 | int err = *((int *) data); | |
333 | if (err) | |
334 | return __put_user(err, st->user_err++); | |
335 | else | |
336 | st->user_err++; | |
337 | } | |
338 | ||
339 | return 0; | |
1c5de193 JF |
340 | } |
341 | ||
d71f5139 MR |
342 | /* Allocate pfns that are then mapped with gmfns from foreign domid. Update |
343 | * the vma with the page info to use later. | |
344 | * Returns: 0 if success, otherwise -errno | |
345 | */ | |
346 | static int alloc_empty_pages(struct vm_area_struct *vma, int numpgs) | |
347 | { | |
348 | int rc; | |
349 | struct page **pages; | |
350 | ||
351 | pages = kcalloc(numpgs, sizeof(pages[0]), GFP_KERNEL); | |
352 | if (pages == NULL) | |
353 | return -ENOMEM; | |
354 | ||
355 | rc = alloc_xenballooned_pages(numpgs, pages, 0); | |
356 | if (rc != 0) { | |
357 | pr_warn("%s Could not alloc %d pfns rc:%d\n", __func__, | |
358 | numpgs, rc); | |
359 | kfree(pages); | |
360 | return -ENOMEM; | |
361 | } | |
a5deabe0 | 362 | BUG_ON(vma->vm_private_data != NULL); |
d71f5139 MR |
363 | vma->vm_private_data = pages; |
364 | ||
365 | return 0; | |
366 | } | |
367 | ||
f31fdf51 JF |
368 | static struct vm_operations_struct privcmd_vm_ops; |
369 | ||
ceb90fa0 | 370 | static long privcmd_ioctl_mmap_batch(void __user *udata, int version) |
1c5de193 JF |
371 | { |
372 | int ret; | |
ceb90fa0 | 373 | struct privcmd_mmapbatch_v2 m; |
1c5de193 JF |
374 | struct mm_struct *mm = current->mm; |
375 | struct vm_area_struct *vma; | |
376 | unsigned long nr_pages; | |
377 | LIST_HEAD(pagelist); | |
378 | struct mmap_batch_state state; | |
379 | ||
ceb90fa0 ALC |
380 | switch (version) { |
381 | case 1: | |
382 | if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch))) | |
383 | return -EFAULT; | |
384 | /* Returns per-frame error in m.arr. */ | |
385 | m.err = NULL; | |
386 | if (!access_ok(VERIFY_WRITE, m.arr, m.num * sizeof(*m.arr))) | |
387 | return -EFAULT; | |
388 | break; | |
389 | case 2: | |
390 | if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch_v2))) | |
391 | return -EFAULT; | |
392 | /* Returns per-frame error code in m.err. */ | |
393 | if (!access_ok(VERIFY_WRITE, m.err, m.num * (sizeof(*m.err)))) | |
394 | return -EFAULT; | |
395 | break; | |
396 | default: | |
397 | return -EINVAL; | |
398 | } | |
1c5de193 JF |
399 | |
400 | nr_pages = m.num; | |
401 | if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT))) | |
402 | return -EINVAL; | |
403 | ||
ceb90fa0 | 404 | ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), m.arr); |
1c5de193 | 405 | |
ceb90fa0 | 406 | if (ret) |
1c5de193 | 407 | goto out; |
ceb90fa0 ALC |
408 | if (list_empty(&pagelist)) { |
409 | ret = -EINVAL; | |
410 | goto out; | |
411 | } | |
412 | ||
99beae6c ALC |
413 | if (version == 2) { |
414 | /* Zero error array now to only copy back actual errors. */ | |
415 | if (clear_user(m.err, sizeof(int) * m.num)) { | |
416 | ret = -EFAULT; | |
417 | goto out; | |
418 | } | |
ceb90fa0 | 419 | } |
1c5de193 JF |
420 | |
421 | down_write(&mm->mmap_sem); | |
422 | ||
423 | vma = find_vma(mm, m.addr); | |
1c5de193 | 424 | if (!vma || |
a5deabe0 | 425 | vma->vm_ops != &privcmd_vm_ops) { |
68fa965d | 426 | ret = -EINVAL; |
a5deabe0 | 427 | goto out_unlock; |
1c5de193 | 428 | } |
a5deabe0 ALC |
429 | |
430 | /* | |
431 | * Caller must either: | |
432 | * | |
433 | * Map the whole VMA range, which will also allocate all the | |
434 | * pages required for the auto_translated_physmap case. | |
435 | * | |
436 | * Or | |
437 | * | |
438 | * Map unmapped holes left from a previous map attempt (e.g., | |
439 | * because those foreign frames were previously paged out). | |
440 | */ | |
441 | if (vma->vm_private_data == NULL) { | |
442 | if (m.addr != vma->vm_start || | |
443 | m.addr + (nr_pages << PAGE_SHIFT) != vma->vm_end) { | |
444 | ret = -EINVAL; | |
445 | goto out_unlock; | |
446 | } | |
447 | if (xen_feature(XENFEAT_auto_translated_physmap)) { | |
448 | ret = alloc_empty_pages(vma, m.num); | |
449 | if (ret < 0) | |
450 | goto out_unlock; | |
451 | } else | |
452 | vma->vm_private_data = PRIV_VMA_LOCKED; | |
453 | } else { | |
454 | if (m.addr < vma->vm_start || | |
455 | m.addr + (nr_pages << PAGE_SHIFT) > vma->vm_end) { | |
456 | ret = -EINVAL; | |
457 | goto out_unlock; | |
458 | } | |
459 | if (privcmd_vma_range_is_mapped(vma, m.addr, nr_pages)) { | |
460 | ret = -EINVAL; | |
461 | goto out_unlock; | |
d71f5139 MR |
462 | } |
463 | } | |
1c5de193 | 464 | |
ceb90fa0 ALC |
465 | state.domain = m.dom; |
466 | state.vma = vma; | |
467 | state.va = m.addr; | |
d71f5139 | 468 | state.index = 0; |
ceb90fa0 | 469 | state.global_error = 0; |
99beae6c | 470 | state.version = version; |
1c5de193 | 471 | |
ceb90fa0 ALC |
472 | /* mmap_batch_fn guarantees ret == 0 */ |
473 | BUG_ON(traverse_pages(m.num, sizeof(xen_pfn_t), | |
474 | &pagelist, mmap_batch_fn, &state)); | |
1c5de193 JF |
475 | |
476 | up_write(&mm->mmap_sem); | |
477 | ||
99beae6c ALC |
478 | if (state.global_error) { |
479 | /* Write back errors in second pass. */ | |
480 | state.user_mfn = (xen_pfn_t *)m.arr; | |
481 | state.user_err = m.err; | |
482 | ret = traverse_pages(m.num, sizeof(xen_pfn_t), | |
483 | &pagelist, mmap_return_errors, &state); | |
484 | } else | |
485 | ret = 0; | |
ceb90fa0 ALC |
486 | |
487 | /* If we have not had any EFAULT-like global errors then set the global | |
488 | * error to -ENOENT if necessary. */ | |
489 | if ((ret == 0) && (state.global_error == -ENOENT)) | |
490 | ret = -ENOENT; | |
1c5de193 JF |
491 | |
492 | out: | |
493 | free_page_list(&pagelist); | |
1c5de193 | 494 | return ret; |
a5deabe0 ALC |
495 | |
496 | out_unlock: | |
497 | up_write(&mm->mmap_sem); | |
498 | goto out; | |
1c5de193 JF |
499 | } |
500 | ||
501 | static long privcmd_ioctl(struct file *file, | |
502 | unsigned int cmd, unsigned long data) | |
503 | { | |
504 | int ret = -ENOSYS; | |
505 | void __user *udata = (void __user *) data; | |
506 | ||
507 | switch (cmd) { | |
508 | case IOCTL_PRIVCMD_HYPERCALL: | |
509 | ret = privcmd_ioctl_hypercall(udata); | |
510 | break; | |
511 | ||
512 | case IOCTL_PRIVCMD_MMAP: | |
513 | ret = privcmd_ioctl_mmap(udata); | |
514 | break; | |
515 | ||
516 | case IOCTL_PRIVCMD_MMAPBATCH: | |
ceb90fa0 ALC |
517 | ret = privcmd_ioctl_mmap_batch(udata, 1); |
518 | break; | |
519 | ||
520 | case IOCTL_PRIVCMD_MMAPBATCH_V2: | |
521 | ret = privcmd_ioctl_mmap_batch(udata, 2); | |
1c5de193 JF |
522 | break; |
523 | ||
524 | default: | |
525 | ret = -EINVAL; | |
526 | break; | |
527 | } | |
528 | ||
529 | return ret; | |
530 | } | |
531 | ||
d71f5139 MR |
532 | static void privcmd_close(struct vm_area_struct *vma) |
533 | { | |
534 | struct page **pages = vma->vm_private_data; | |
535 | int numpgs = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
536 | ||
9eff37a8 | 537 | if (!xen_feature(XENFEAT_auto_translated_physmap) || !numpgs || !pages) |
d71f5139 MR |
538 | return; |
539 | ||
540 | xen_unmap_domain_mfn_range(vma, numpgs, pages); | |
541 | free_xenballooned_pages(numpgs, pages); | |
542 | kfree(pages); | |
543 | } | |
544 | ||
1c5de193 JF |
545 | static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
546 | { | |
441c7416 JF |
547 | printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n", |
548 | vma, vma->vm_start, vma->vm_end, | |
549 | vmf->pgoff, vmf->virtual_address); | |
550 | ||
1c5de193 JF |
551 | return VM_FAULT_SIGBUS; |
552 | } | |
553 | ||
554 | static struct vm_operations_struct privcmd_vm_ops = { | |
d71f5139 | 555 | .close = privcmd_close, |
1c5de193 JF |
556 | .fault = privcmd_fault |
557 | }; | |
558 | ||
559 | static int privcmd_mmap(struct file *file, struct vm_area_struct *vma) | |
560 | { | |
e060e7af SS |
561 | /* DONTCOPY is essential for Xen because copy_page_range doesn't know |
562 | * how to recreate these mappings */ | |
314e51b9 KK |
563 | vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTCOPY | |
564 | VM_DONTEXPAND | VM_DONTDUMP; | |
1c5de193 JF |
565 | vma->vm_ops = &privcmd_vm_ops; |
566 | vma->vm_private_data = NULL; | |
567 | ||
568 | return 0; | |
569 | } | |
570 | ||
a5deabe0 ALC |
571 | /* |
572 | * For MMAPBATCH*. This allows asserting the singleshot mapping | |
573 | * on a per pfn/pte basis. Mapping calls that fail with ENOENT | |
574 | * can be then retried until success. | |
575 | */ | |
576 | static int is_mapped_fn(pte_t *pte, struct page *pmd_page, | |
577 | unsigned long addr, void *data) | |
578 | { | |
579 | return pte_none(*pte) ? 0 : -EBUSY; | |
580 | } | |
581 | ||
582 | static int privcmd_vma_range_is_mapped( | |
583 | struct vm_area_struct *vma, | |
584 | unsigned long addr, | |
585 | unsigned long nr_pages) | |
1c5de193 | 586 | { |
a5deabe0 ALC |
587 | return apply_to_page_range(vma->vm_mm, addr, nr_pages << PAGE_SHIFT, |
588 | is_mapped_fn, NULL) != 0; | |
1c5de193 | 589 | } |
1c5de193 | 590 | |
d8414d3c BB |
591 | const struct file_operations xen_privcmd_fops = { |
592 | .owner = THIS_MODULE, | |
1c5de193 JF |
593 | .unlocked_ioctl = privcmd_ioctl, |
594 | .mmap = privcmd_mmap, | |
595 | }; | |
d8414d3c BB |
596 | EXPORT_SYMBOL_GPL(xen_privcmd_fops); |
597 | ||
598 | static struct miscdevice privcmd_dev = { | |
599 | .minor = MISC_DYNAMIC_MINOR, | |
600 | .name = "xen/privcmd", | |
601 | .fops = &xen_privcmd_fops, | |
602 | }; | |
603 | ||
604 | static int __init privcmd_init(void) | |
605 | { | |
606 | int err; | |
607 | ||
608 | if (!xen_domain()) | |
609 | return -ENODEV; | |
610 | ||
611 | err = misc_register(&privcmd_dev); | |
612 | if (err != 0) { | |
283c0972 | 613 | pr_err("Could not register Xen privcmd device\n"); |
d8414d3c BB |
614 | return err; |
615 | } | |
616 | return 0; | |
617 | } | |
618 | ||
619 | static void __exit privcmd_exit(void) | |
620 | { | |
621 | misc_deregister(&privcmd_dev); | |
622 | } | |
623 | ||
624 | module_init(privcmd_init); | |
625 | module_exit(privcmd_exit); |