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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1c5de193 JF |
2 | /****************************************************************************** |
3 | * privcmd.c | |
4 | * | |
5 | * Interface to privileged domain-0 commands. | |
6 | * | |
7 | * Copyright (c) 2002-2004, K A Fraser, B Dragovic | |
8 | */ | |
9 | ||
283c0972 JP |
10 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt |
11 | ||
1c5de193 | 12 | #include <linux/kernel.h> |
d8414d3c | 13 | #include <linux/module.h> |
1c5de193 JF |
14 | #include <linux/sched.h> |
15 | #include <linux/slab.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/errno.h> | |
18 | #include <linux/mm.h> | |
19 | #include <linux/mman.h> | |
20 | #include <linux/uaccess.h> | |
21 | #include <linux/swap.h> | |
1c5de193 JF |
22 | #include <linux/highmem.h> |
23 | #include <linux/pagemap.h> | |
24 | #include <linux/seq_file.h> | |
d8414d3c | 25 | #include <linux/miscdevice.h> |
ab520be8 | 26 | #include <linux/moduleparam.h> |
1c5de193 JF |
27 | |
28 | #include <asm/pgalloc.h> | |
29 | #include <asm/pgtable.h> | |
30 | #include <asm/tlb.h> | |
31 | #include <asm/xen/hypervisor.h> | |
32 | #include <asm/xen/hypercall.h> | |
33 | ||
34 | #include <xen/xen.h> | |
35 | #include <xen/privcmd.h> | |
36 | #include <xen/interface/xen.h> | |
3ad08765 | 37 | #include <xen/interface/memory.h> |
ab520be8 | 38 | #include <xen/interface/hvm/dm_op.h> |
1c5de193 JF |
39 | #include <xen/features.h> |
40 | #include <xen/page.h> | |
de1ef206 | 41 | #include <xen/xen-ops.h> |
d71f5139 | 42 | #include <xen/balloon.h> |
f020e290 | 43 | |
d8414d3c BB |
44 | #include "privcmd.h" |
45 | ||
46 | MODULE_LICENSE("GPL"); | |
47 | ||
d71f5139 MR |
48 | #define PRIV_VMA_LOCKED ((void *)1) |
49 | ||
ab520be8 PD |
50 | static unsigned int privcmd_dm_op_max_num = 16; |
51 | module_param_named(dm_op_max_nr_bufs, privcmd_dm_op_max_num, uint, 0644); | |
52 | MODULE_PARM_DESC(dm_op_max_nr_bufs, | |
53 | "Maximum number of buffers per dm_op hypercall"); | |
54 | ||
55 | static unsigned int privcmd_dm_op_buf_max_size = 4096; | |
56 | module_param_named(dm_op_buf_max_size, privcmd_dm_op_buf_max_size, uint, | |
57 | 0644); | |
58 | MODULE_PARM_DESC(dm_op_buf_max_size, | |
59 | "Maximum size of a dm_op hypercall buffer"); | |
60 | ||
4610d240 PD |
61 | struct privcmd_data { |
62 | domid_t domid; | |
63 | }; | |
64 | ||
a5deabe0 ALC |
65 | static int privcmd_vma_range_is_mapped( |
66 | struct vm_area_struct *vma, | |
67 | unsigned long addr, | |
68 | unsigned long nr_pages); | |
1c5de193 | 69 | |
4610d240 | 70 | static long privcmd_ioctl_hypercall(struct file *file, void __user *udata) |
1c5de193 | 71 | { |
4610d240 | 72 | struct privcmd_data *data = file->private_data; |
1c5de193 JF |
73 | struct privcmd_hypercall hypercall; |
74 | long ret; | |
75 | ||
4610d240 PD |
76 | /* Disallow arbitrary hypercalls if restricted */ |
77 | if (data->domid != DOMID_INVALID) | |
78 | return -EPERM; | |
79 | ||
1c5de193 JF |
80 | if (copy_from_user(&hypercall, udata, sizeof(hypercall))) |
81 | return -EFAULT; | |
82 | ||
fdfd811d | 83 | xen_preemptible_hcall_begin(); |
1c5de193 JF |
84 | ret = privcmd_call(hypercall.op, |
85 | hypercall.arg[0], hypercall.arg[1], | |
86 | hypercall.arg[2], hypercall.arg[3], | |
87 | hypercall.arg[4]); | |
fdfd811d | 88 | xen_preemptible_hcall_end(); |
1c5de193 JF |
89 | |
90 | return ret; | |
91 | } | |
92 | ||
93 | static void free_page_list(struct list_head *pages) | |
94 | { | |
95 | struct page *p, *n; | |
96 | ||
97 | list_for_each_entry_safe(p, n, pages, lru) | |
98 | __free_page(p); | |
99 | ||
100 | INIT_LIST_HEAD(pages); | |
101 | } | |
102 | ||
103 | /* | |
104 | * Given an array of items in userspace, return a list of pages | |
105 | * containing the data. If copying fails, either because of memory | |
106 | * allocation failure or a problem reading user memory, return an | |
107 | * error code; its up to the caller to dispose of any partial list. | |
108 | */ | |
109 | static int gather_array(struct list_head *pagelist, | |
110 | unsigned nelem, size_t size, | |
ceb90fa0 | 111 | const void __user *data) |
1c5de193 JF |
112 | { |
113 | unsigned pageidx; | |
114 | void *pagedata; | |
115 | int ret; | |
116 | ||
117 | if (size > PAGE_SIZE) | |
118 | return 0; | |
119 | ||
120 | pageidx = PAGE_SIZE; | |
121 | pagedata = NULL; /* quiet, gcc */ | |
122 | while (nelem--) { | |
123 | if (pageidx > PAGE_SIZE-size) { | |
124 | struct page *page = alloc_page(GFP_KERNEL); | |
125 | ||
126 | ret = -ENOMEM; | |
127 | if (page == NULL) | |
128 | goto fail; | |
129 | ||
130 | pagedata = page_address(page); | |
131 | ||
132 | list_add_tail(&page->lru, pagelist); | |
133 | pageidx = 0; | |
134 | } | |
135 | ||
136 | ret = -EFAULT; | |
137 | if (copy_from_user(pagedata + pageidx, data, size)) | |
138 | goto fail; | |
139 | ||
140 | data += size; | |
141 | pageidx += size; | |
142 | } | |
143 | ||
144 | ret = 0; | |
145 | ||
146 | fail: | |
147 | return ret; | |
148 | } | |
149 | ||
150 | /* | |
151 | * Call function "fn" on each element of the array fragmented | |
152 | * over a list of pages. | |
153 | */ | |
154 | static int traverse_pages(unsigned nelem, size_t size, | |
155 | struct list_head *pos, | |
156 | int (*fn)(void *data, void *state), | |
157 | void *state) | |
158 | { | |
159 | void *pagedata; | |
160 | unsigned pageidx; | |
f020e290 | 161 | int ret = 0; |
1c5de193 JF |
162 | |
163 | BUG_ON(size > PAGE_SIZE); | |
164 | ||
165 | pageidx = PAGE_SIZE; | |
166 | pagedata = NULL; /* hush, gcc */ | |
167 | ||
168 | while (nelem--) { | |
169 | if (pageidx > PAGE_SIZE-size) { | |
170 | struct page *page; | |
171 | pos = pos->next; | |
172 | page = list_entry(pos, struct page, lru); | |
173 | pagedata = page_address(page); | |
174 | pageidx = 0; | |
175 | } | |
176 | ||
177 | ret = (*fn)(pagedata + pageidx, state); | |
178 | if (ret) | |
179 | break; | |
180 | pageidx += size; | |
181 | } | |
182 | ||
183 | return ret; | |
184 | } | |
185 | ||
4e8c0c8c DV |
186 | /* |
187 | * Similar to traverse_pages, but use each page as a "block" of | |
188 | * data to be processed as one unit. | |
189 | */ | |
190 | static int traverse_pages_block(unsigned nelem, size_t size, | |
191 | struct list_head *pos, | |
192 | int (*fn)(void *data, int nr, void *state), | |
193 | void *state) | |
194 | { | |
195 | void *pagedata; | |
4e8c0c8c DV |
196 | int ret = 0; |
197 | ||
198 | BUG_ON(size > PAGE_SIZE); | |
199 | ||
4e8c0c8c DV |
200 | while (nelem) { |
201 | int nr = (PAGE_SIZE/size); | |
202 | struct page *page; | |
203 | if (nr > nelem) | |
204 | nr = nelem; | |
205 | pos = pos->next; | |
206 | page = list_entry(pos, struct page, lru); | |
207 | pagedata = page_address(page); | |
208 | ret = (*fn)(pagedata, nr, state); | |
209 | if (ret) | |
210 | break; | |
211 | nelem -= nr; | |
212 | } | |
213 | ||
214 | return ret; | |
215 | } | |
216 | ||
a13d7201 | 217 | struct mmap_gfn_state { |
1c5de193 JF |
218 | unsigned long va; |
219 | struct vm_area_struct *vma; | |
220 | domid_t domain; | |
221 | }; | |
222 | ||
a13d7201 | 223 | static int mmap_gfn_range(void *data, void *state) |
1c5de193 JF |
224 | { |
225 | struct privcmd_mmap_entry *msg = data; | |
a13d7201 | 226 | struct mmap_gfn_state *st = state; |
1c5de193 JF |
227 | struct vm_area_struct *vma = st->vma; |
228 | int rc; | |
229 | ||
230 | /* Do not allow range to wrap the address space. */ | |
231 | if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) || | |
232 | ((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va)) | |
233 | return -EINVAL; | |
234 | ||
235 | /* Range chunks must be contiguous in va space. */ | |
236 | if ((msg->va != st->va) || | |
237 | ((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end)) | |
238 | return -EINVAL; | |
239 | ||
a13d7201 | 240 | rc = xen_remap_domain_gfn_range(vma, |
de1ef206 IC |
241 | msg->va & PAGE_MASK, |
242 | msg->mfn, msg->npages, | |
243 | vma->vm_page_prot, | |
9a032e39 | 244 | st->domain, NULL); |
1c5de193 JF |
245 | if (rc < 0) |
246 | return rc; | |
247 | ||
248 | st->va += msg->npages << PAGE_SHIFT; | |
249 | ||
250 | return 0; | |
251 | } | |
252 | ||
4610d240 | 253 | static long privcmd_ioctl_mmap(struct file *file, void __user *udata) |
1c5de193 | 254 | { |
4610d240 | 255 | struct privcmd_data *data = file->private_data; |
1c5de193 JF |
256 | struct privcmd_mmap mmapcmd; |
257 | struct mm_struct *mm = current->mm; | |
258 | struct vm_area_struct *vma; | |
259 | int rc; | |
260 | LIST_HEAD(pagelist); | |
a13d7201 | 261 | struct mmap_gfn_state state; |
1c5de193 | 262 | |
d71f5139 MR |
263 | /* We only support privcmd_ioctl_mmap_batch for auto translated. */ |
264 | if (xen_feature(XENFEAT_auto_translated_physmap)) | |
265 | return -ENOSYS; | |
266 | ||
1c5de193 JF |
267 | if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd))) |
268 | return -EFAULT; | |
269 | ||
4610d240 PD |
270 | /* If restriction is in place, check the domid matches */ |
271 | if (data->domid != DOMID_INVALID && data->domid != mmapcmd.dom) | |
272 | return -EPERM; | |
273 | ||
1c5de193 JF |
274 | rc = gather_array(&pagelist, |
275 | mmapcmd.num, sizeof(struct privcmd_mmap_entry), | |
276 | mmapcmd.entry); | |
277 | ||
278 | if (rc || list_empty(&pagelist)) | |
279 | goto out; | |
280 | ||
281 | down_write(&mm->mmap_sem); | |
282 | ||
283 | { | |
284 | struct page *page = list_first_entry(&pagelist, | |
285 | struct page, lru); | |
286 | struct privcmd_mmap_entry *msg = page_address(page); | |
287 | ||
288 | vma = find_vma(mm, msg->va); | |
289 | rc = -EINVAL; | |
290 | ||
a5deabe0 | 291 | if (!vma || (msg->va != vma->vm_start) || vma->vm_private_data) |
1c5de193 | 292 | goto out_up; |
a5deabe0 | 293 | vma->vm_private_data = PRIV_VMA_LOCKED; |
1c5de193 JF |
294 | } |
295 | ||
296 | state.va = vma->vm_start; | |
297 | state.vma = vma; | |
298 | state.domain = mmapcmd.dom; | |
299 | ||
300 | rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry), | |
301 | &pagelist, | |
a13d7201 | 302 | mmap_gfn_range, &state); |
1c5de193 JF |
303 | |
304 | ||
305 | out_up: | |
306 | up_write(&mm->mmap_sem); | |
307 | ||
308 | out: | |
309 | free_page_list(&pagelist); | |
310 | ||
311 | return rc; | |
312 | } | |
313 | ||
314 | struct mmap_batch_state { | |
315 | domid_t domain; | |
316 | unsigned long va; | |
317 | struct vm_area_struct *vma; | |
d71f5139 | 318 | int index; |
ceb90fa0 ALC |
319 | /* A tristate: |
320 | * 0 for no errors | |
321 | * 1 if at least one error has happened (and no | |
322 | * -ENOENT errors have happened) | |
323 | * -ENOENT if at least 1 -ENOENT has happened. | |
324 | */ | |
325 | int global_error; | |
99beae6c | 326 | int version; |
ceb90fa0 | 327 | |
a13d7201 JG |
328 | /* User-space gfn array to store errors in the second pass for V1. */ |
329 | xen_pfn_t __user *user_gfn; | |
99beae6c ALC |
330 | /* User-space int array to store errors in the second pass for V2. */ |
331 | int __user *user_err; | |
1c5de193 JF |
332 | }; |
333 | ||
a13d7201 JG |
334 | /* auto translated dom0 note: if domU being created is PV, then gfn is |
335 | * mfn(addr on bus). If it's auto xlated, then gfn is pfn (input to HAP). | |
d71f5139 | 336 | */ |
4e8c0c8c | 337 | static int mmap_batch_fn(void *data, int nr, void *state) |
1c5de193 | 338 | { |
a13d7201 | 339 | xen_pfn_t *gfnp = data; |
1c5de193 | 340 | struct mmap_batch_state *st = state; |
d71f5139 MR |
341 | struct vm_area_struct *vma = st->vma; |
342 | struct page **pages = vma->vm_private_data; | |
4e8c0c8c | 343 | struct page **cur_pages = NULL; |
ceb90fa0 ALC |
344 | int ret; |
345 | ||
d71f5139 | 346 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
4e8c0c8c | 347 | cur_pages = &pages[st->index]; |
d71f5139 | 348 | |
4e8c0c8c | 349 | BUG_ON(nr < 0); |
a13d7201 JG |
350 | ret = xen_remap_domain_gfn_array(st->vma, st->va & PAGE_MASK, gfnp, nr, |
351 | (int *)gfnp, st->vma->vm_page_prot, | |
4e8c0c8c | 352 | st->domain, cur_pages); |
1c5de193 | 353 | |
4e8c0c8c DV |
354 | /* Adjust the global_error? */ |
355 | if (ret != nr) { | |
ceb90fa0 ALC |
356 | if (ret == -ENOENT) |
357 | st->global_error = -ENOENT; | |
358 | else { | |
359 | /* Record that at least one error has happened. */ | |
360 | if (st->global_error == 0) | |
361 | st->global_error = 1; | |
362 | } | |
1c5de193 | 363 | } |
753c09b5 JG |
364 | st->va += XEN_PAGE_SIZE * nr; |
365 | st->index += nr / XEN_PFN_PER_PAGE; | |
1c5de193 JF |
366 | |
367 | return 0; | |
368 | } | |
369 | ||
4e8c0c8c | 370 | static int mmap_return_error(int err, struct mmap_batch_state *st) |
1c5de193 | 371 | { |
4e8c0c8c | 372 | int ret; |
ceb90fa0 | 373 | |
99beae6c | 374 | if (st->version == 1) { |
4e8c0c8c | 375 | if (err) { |
a13d7201 | 376 | xen_pfn_t gfn; |
4e8c0c8c | 377 | |
a13d7201 | 378 | ret = get_user(gfn, st->user_gfn); |
4e8c0c8c DV |
379 | if (ret < 0) |
380 | return ret; | |
381 | /* | |
382 | * V1 encodes the error codes in the 32bit top | |
a13d7201 | 383 | * nibble of the gfn (with its known |
4e8c0c8c DV |
384 | * limitations vis-a-vis 64 bit callers). |
385 | */ | |
a13d7201 | 386 | gfn |= (err == -ENOENT) ? |
4e8c0c8c DV |
387 | PRIVCMD_MMAPBATCH_PAGED_ERROR : |
388 | PRIVCMD_MMAPBATCH_MFN_ERROR; | |
a13d7201 | 389 | return __put_user(gfn, st->user_gfn++); |
4e8c0c8c | 390 | } else |
a13d7201 | 391 | st->user_gfn++; |
99beae6c | 392 | } else { /* st->version == 2 */ |
99beae6c ALC |
393 | if (err) |
394 | return __put_user(err, st->user_err++); | |
395 | else | |
396 | st->user_err++; | |
397 | } | |
398 | ||
399 | return 0; | |
1c5de193 JF |
400 | } |
401 | ||
4e8c0c8c DV |
402 | static int mmap_return_errors(void *data, int nr, void *state) |
403 | { | |
404 | struct mmap_batch_state *st = state; | |
405 | int *errs = data; | |
406 | int i; | |
407 | int ret; | |
408 | ||
409 | for (i = 0; i < nr; i++) { | |
410 | ret = mmap_return_error(errs[i], st); | |
411 | if (ret < 0) | |
412 | return ret; | |
413 | } | |
414 | return 0; | |
415 | } | |
416 | ||
a13d7201 | 417 | /* Allocate pfns that are then mapped with gfns from foreign domid. Update |
d71f5139 MR |
418 | * the vma with the page info to use later. |
419 | * Returns: 0 if success, otherwise -errno | |
420 | */ | |
421 | static int alloc_empty_pages(struct vm_area_struct *vma, int numpgs) | |
422 | { | |
423 | int rc; | |
424 | struct page **pages; | |
425 | ||
426 | pages = kcalloc(numpgs, sizeof(pages[0]), GFP_KERNEL); | |
427 | if (pages == NULL) | |
428 | return -ENOMEM; | |
429 | ||
81b286e0 | 430 | rc = alloc_xenballooned_pages(numpgs, pages); |
d71f5139 MR |
431 | if (rc != 0) { |
432 | pr_warn("%s Could not alloc %d pfns rc:%d\n", __func__, | |
433 | numpgs, rc); | |
434 | kfree(pages); | |
435 | return -ENOMEM; | |
436 | } | |
a5deabe0 | 437 | BUG_ON(vma->vm_private_data != NULL); |
d71f5139 MR |
438 | vma->vm_private_data = pages; |
439 | ||
440 | return 0; | |
441 | } | |
442 | ||
7cbea8dc | 443 | static const struct vm_operations_struct privcmd_vm_ops; |
f31fdf51 | 444 | |
4610d240 PD |
445 | static long privcmd_ioctl_mmap_batch( |
446 | struct file *file, void __user *udata, int version) | |
1c5de193 | 447 | { |
4610d240 | 448 | struct privcmd_data *data = file->private_data; |
1c5de193 | 449 | int ret; |
ceb90fa0 | 450 | struct privcmd_mmapbatch_v2 m; |
1c5de193 JF |
451 | struct mm_struct *mm = current->mm; |
452 | struct vm_area_struct *vma; | |
453 | unsigned long nr_pages; | |
454 | LIST_HEAD(pagelist); | |
455 | struct mmap_batch_state state; | |
456 | ||
ceb90fa0 ALC |
457 | switch (version) { |
458 | case 1: | |
459 | if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch))) | |
460 | return -EFAULT; | |
461 | /* Returns per-frame error in m.arr. */ | |
462 | m.err = NULL; | |
96d4f267 | 463 | if (!access_ok(m.arr, m.num * sizeof(*m.arr))) |
ceb90fa0 ALC |
464 | return -EFAULT; |
465 | break; | |
466 | case 2: | |
467 | if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch_v2))) | |
468 | return -EFAULT; | |
469 | /* Returns per-frame error code in m.err. */ | |
96d4f267 | 470 | if (!access_ok(m.err, m.num * (sizeof(*m.err)))) |
ceb90fa0 ALC |
471 | return -EFAULT; |
472 | break; | |
473 | default: | |
474 | return -EINVAL; | |
475 | } | |
1c5de193 | 476 | |
4610d240 PD |
477 | /* If restriction is in place, check the domid matches */ |
478 | if (data->domid != DOMID_INVALID && data->domid != m.dom) | |
479 | return -EPERM; | |
480 | ||
5995a68a | 481 | nr_pages = DIV_ROUND_UP(m.num, XEN_PFN_PER_PAGE); |
1c5de193 JF |
482 | if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT))) |
483 | return -EINVAL; | |
484 | ||
ceb90fa0 | 485 | ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), m.arr); |
1c5de193 | 486 | |
ceb90fa0 | 487 | if (ret) |
1c5de193 | 488 | goto out; |
ceb90fa0 ALC |
489 | if (list_empty(&pagelist)) { |
490 | ret = -EINVAL; | |
491 | goto out; | |
492 | } | |
493 | ||
99beae6c ALC |
494 | if (version == 2) { |
495 | /* Zero error array now to only copy back actual errors. */ | |
496 | if (clear_user(m.err, sizeof(int) * m.num)) { | |
497 | ret = -EFAULT; | |
498 | goto out; | |
499 | } | |
ceb90fa0 | 500 | } |
1c5de193 JF |
501 | |
502 | down_write(&mm->mmap_sem); | |
503 | ||
504 | vma = find_vma(mm, m.addr); | |
1c5de193 | 505 | if (!vma || |
a5deabe0 | 506 | vma->vm_ops != &privcmd_vm_ops) { |
68fa965d | 507 | ret = -EINVAL; |
a5deabe0 | 508 | goto out_unlock; |
1c5de193 | 509 | } |
a5deabe0 ALC |
510 | |
511 | /* | |
512 | * Caller must either: | |
513 | * | |
514 | * Map the whole VMA range, which will also allocate all the | |
515 | * pages required for the auto_translated_physmap case. | |
516 | * | |
517 | * Or | |
518 | * | |
519 | * Map unmapped holes left from a previous map attempt (e.g., | |
520 | * because those foreign frames were previously paged out). | |
521 | */ | |
522 | if (vma->vm_private_data == NULL) { | |
523 | if (m.addr != vma->vm_start || | |
524 | m.addr + (nr_pages << PAGE_SHIFT) != vma->vm_end) { | |
525 | ret = -EINVAL; | |
526 | goto out_unlock; | |
527 | } | |
528 | if (xen_feature(XENFEAT_auto_translated_physmap)) { | |
5995a68a | 529 | ret = alloc_empty_pages(vma, nr_pages); |
a5deabe0 ALC |
530 | if (ret < 0) |
531 | goto out_unlock; | |
532 | } else | |
533 | vma->vm_private_data = PRIV_VMA_LOCKED; | |
534 | } else { | |
535 | if (m.addr < vma->vm_start || | |
536 | m.addr + (nr_pages << PAGE_SHIFT) > vma->vm_end) { | |
537 | ret = -EINVAL; | |
538 | goto out_unlock; | |
539 | } | |
540 | if (privcmd_vma_range_is_mapped(vma, m.addr, nr_pages)) { | |
541 | ret = -EINVAL; | |
542 | goto out_unlock; | |
d71f5139 MR |
543 | } |
544 | } | |
1c5de193 | 545 | |
ceb90fa0 ALC |
546 | state.domain = m.dom; |
547 | state.vma = vma; | |
548 | state.va = m.addr; | |
d71f5139 | 549 | state.index = 0; |
ceb90fa0 | 550 | state.global_error = 0; |
99beae6c | 551 | state.version = version; |
1c5de193 | 552 | |
5995a68a | 553 | BUILD_BUG_ON(((PAGE_SIZE / sizeof(xen_pfn_t)) % XEN_PFN_PER_PAGE) != 0); |
ceb90fa0 | 554 | /* mmap_batch_fn guarantees ret == 0 */ |
4e8c0c8c DV |
555 | BUG_ON(traverse_pages_block(m.num, sizeof(xen_pfn_t), |
556 | &pagelist, mmap_batch_fn, &state)); | |
1c5de193 JF |
557 | |
558 | up_write(&mm->mmap_sem); | |
559 | ||
99beae6c ALC |
560 | if (state.global_error) { |
561 | /* Write back errors in second pass. */ | |
a13d7201 | 562 | state.user_gfn = (xen_pfn_t *)m.arr; |
99beae6c | 563 | state.user_err = m.err; |
4e8c0c8c DV |
564 | ret = traverse_pages_block(m.num, sizeof(xen_pfn_t), |
565 | &pagelist, mmap_return_errors, &state); | |
99beae6c ALC |
566 | } else |
567 | ret = 0; | |
ceb90fa0 ALC |
568 | |
569 | /* If we have not had any EFAULT-like global errors then set the global | |
570 | * error to -ENOENT if necessary. */ | |
571 | if ((ret == 0) && (state.global_error == -ENOENT)) | |
572 | ret = -ENOENT; | |
1c5de193 JF |
573 | |
574 | out: | |
575 | free_page_list(&pagelist); | |
1c5de193 | 576 | return ret; |
a5deabe0 ALC |
577 | |
578 | out_unlock: | |
579 | up_write(&mm->mmap_sem); | |
580 | goto out; | |
1c5de193 JF |
581 | } |
582 | ||
ab520be8 PD |
583 | static int lock_pages( |
584 | struct privcmd_dm_op_buf kbufs[], unsigned int num, | |
585 | struct page *pages[], unsigned int nr_pages) | |
586 | { | |
587 | unsigned int i; | |
588 | ||
589 | for (i = 0; i < num; i++) { | |
590 | unsigned int requested; | |
591 | int pinned; | |
592 | ||
593 | requested = DIV_ROUND_UP( | |
594 | offset_in_page(kbufs[i].uptr) + kbufs[i].size, | |
595 | PAGE_SIZE); | |
596 | if (requested > nr_pages) | |
597 | return -ENOSPC; | |
598 | ||
599 | pinned = get_user_pages_fast( | |
600 | (unsigned long) kbufs[i].uptr, | |
601 | requested, FOLL_WRITE, pages); | |
602 | if (pinned < 0) | |
603 | return pinned; | |
604 | ||
605 | nr_pages -= pinned; | |
606 | pages += pinned; | |
607 | } | |
608 | ||
609 | return 0; | |
610 | } | |
611 | ||
612 | static void unlock_pages(struct page *pages[], unsigned int nr_pages) | |
613 | { | |
614 | unsigned int i; | |
615 | ||
616 | if (!pages) | |
617 | return; | |
618 | ||
619 | for (i = 0; i < nr_pages; i++) { | |
620 | if (pages[i]) | |
621 | put_page(pages[i]); | |
622 | } | |
623 | } | |
624 | ||
4610d240 | 625 | static long privcmd_ioctl_dm_op(struct file *file, void __user *udata) |
ab520be8 | 626 | { |
4610d240 | 627 | struct privcmd_data *data = file->private_data; |
ab520be8 PD |
628 | struct privcmd_dm_op kdata; |
629 | struct privcmd_dm_op_buf *kbufs; | |
630 | unsigned int nr_pages = 0; | |
631 | struct page **pages = NULL; | |
632 | struct xen_dm_op_buf *xbufs = NULL; | |
633 | unsigned int i; | |
634 | long rc; | |
635 | ||
636 | if (copy_from_user(&kdata, udata, sizeof(kdata))) | |
637 | return -EFAULT; | |
638 | ||
4610d240 PD |
639 | /* If restriction is in place, check the domid matches */ |
640 | if (data->domid != DOMID_INVALID && data->domid != kdata.dom) | |
641 | return -EPERM; | |
642 | ||
ab520be8 PD |
643 | if (kdata.num == 0) |
644 | return 0; | |
645 | ||
646 | if (kdata.num > privcmd_dm_op_max_num) | |
647 | return -E2BIG; | |
648 | ||
649 | kbufs = kcalloc(kdata.num, sizeof(*kbufs), GFP_KERNEL); | |
650 | if (!kbufs) | |
651 | return -ENOMEM; | |
652 | ||
653 | if (copy_from_user(kbufs, kdata.ubufs, | |
654 | sizeof(*kbufs) * kdata.num)) { | |
655 | rc = -EFAULT; | |
656 | goto out; | |
657 | } | |
658 | ||
659 | for (i = 0; i < kdata.num; i++) { | |
660 | if (kbufs[i].size > privcmd_dm_op_buf_max_size) { | |
661 | rc = -E2BIG; | |
662 | goto out; | |
663 | } | |
664 | ||
96d4f267 | 665 | if (!access_ok(kbufs[i].uptr, |
ab520be8 PD |
666 | kbufs[i].size)) { |
667 | rc = -EFAULT; | |
668 | goto out; | |
669 | } | |
670 | ||
671 | nr_pages += DIV_ROUND_UP( | |
672 | offset_in_page(kbufs[i].uptr) + kbufs[i].size, | |
673 | PAGE_SIZE); | |
674 | } | |
675 | ||
676 | pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL); | |
677 | if (!pages) { | |
678 | rc = -ENOMEM; | |
679 | goto out; | |
680 | } | |
681 | ||
682 | xbufs = kcalloc(kdata.num, sizeof(*xbufs), GFP_KERNEL); | |
683 | if (!xbufs) { | |
684 | rc = -ENOMEM; | |
685 | goto out; | |
686 | } | |
687 | ||
688 | rc = lock_pages(kbufs, kdata.num, pages, nr_pages); | |
689 | if (rc) | |
690 | goto out; | |
691 | ||
692 | for (i = 0; i < kdata.num; i++) { | |
693 | set_xen_guest_handle(xbufs[i].h, kbufs[i].uptr); | |
694 | xbufs[i].size = kbufs[i].size; | |
695 | } | |
696 | ||
697 | xen_preemptible_hcall_begin(); | |
698 | rc = HYPERVISOR_dm_op(kdata.dom, kdata.num, xbufs); | |
699 | xen_preemptible_hcall_end(); | |
700 | ||
701 | out: | |
702 | unlock_pages(pages, nr_pages); | |
703 | kfree(xbufs); | |
704 | kfree(pages); | |
705 | kfree(kbufs); | |
706 | ||
707 | return rc; | |
708 | } | |
709 | ||
4610d240 PD |
710 | static long privcmd_ioctl_restrict(struct file *file, void __user *udata) |
711 | { | |
712 | struct privcmd_data *data = file->private_data; | |
713 | domid_t dom; | |
714 | ||
715 | if (copy_from_user(&dom, udata, sizeof(dom))) | |
716 | return -EFAULT; | |
717 | ||
718 | /* Set restriction to the specified domain, or check it matches */ | |
719 | if (data->domid == DOMID_INVALID) | |
720 | data->domid = dom; | |
721 | else if (data->domid != dom) | |
722 | return -EINVAL; | |
723 | ||
724 | return 0; | |
725 | } | |
726 | ||
3ad08765 PD |
727 | struct remap_pfn { |
728 | struct mm_struct *mm; | |
729 | struct page **pages; | |
730 | pgprot_t prot; | |
731 | unsigned long i; | |
732 | }; | |
733 | ||
734 | static int remap_pfn_fn(pte_t *ptep, pgtable_t token, unsigned long addr, | |
735 | void *data) | |
736 | { | |
737 | struct remap_pfn *r = data; | |
738 | struct page *page = r->pages[r->i]; | |
739 | pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), r->prot)); | |
740 | ||
741 | set_pte_at(r->mm, addr, ptep, pte); | |
742 | r->i++; | |
743 | ||
744 | return 0; | |
745 | } | |
746 | ||
747 | static long privcmd_ioctl_mmap_resource(struct file *file, void __user *udata) | |
748 | { | |
749 | struct privcmd_data *data = file->private_data; | |
750 | struct mm_struct *mm = current->mm; | |
751 | struct vm_area_struct *vma; | |
752 | struct privcmd_mmap_resource kdata; | |
753 | xen_pfn_t *pfns = NULL; | |
754 | struct xen_mem_acquire_resource xdata; | |
755 | int rc; | |
756 | ||
757 | if (copy_from_user(&kdata, udata, sizeof(kdata))) | |
758 | return -EFAULT; | |
759 | ||
760 | /* If restriction is in place, check the domid matches */ | |
761 | if (data->domid != DOMID_INVALID && data->domid != kdata.dom) | |
762 | return -EPERM; | |
763 | ||
764 | down_write(&mm->mmap_sem); | |
765 | ||
766 | vma = find_vma(mm, kdata.addr); | |
767 | if (!vma || vma->vm_ops != &privcmd_vm_ops) { | |
768 | rc = -EINVAL; | |
769 | goto out; | |
770 | } | |
771 | ||
772 | pfns = kcalloc(kdata.num, sizeof(*pfns), GFP_KERNEL); | |
773 | if (!pfns) { | |
774 | rc = -ENOMEM; | |
775 | goto out; | |
776 | } | |
777 | ||
778 | if (xen_feature(XENFEAT_auto_translated_physmap)) { | |
779 | unsigned int nr = DIV_ROUND_UP(kdata.num, XEN_PFN_PER_PAGE); | |
780 | struct page **pages; | |
781 | unsigned int i; | |
782 | ||
783 | rc = alloc_empty_pages(vma, nr); | |
784 | if (rc < 0) | |
785 | goto out; | |
786 | ||
787 | pages = vma->vm_private_data; | |
788 | for (i = 0; i < kdata.num; i++) { | |
789 | xen_pfn_t pfn = | |
790 | page_to_xen_pfn(pages[i / XEN_PFN_PER_PAGE]); | |
791 | ||
792 | pfns[i] = pfn + (i % XEN_PFN_PER_PAGE); | |
793 | } | |
794 | } else | |
795 | vma->vm_private_data = PRIV_VMA_LOCKED; | |
796 | ||
797 | memset(&xdata, 0, sizeof(xdata)); | |
798 | xdata.domid = kdata.dom; | |
799 | xdata.type = kdata.type; | |
800 | xdata.id = kdata.id; | |
801 | xdata.frame = kdata.idx; | |
802 | xdata.nr_frames = kdata.num; | |
803 | set_xen_guest_handle(xdata.frame_list, pfns); | |
804 | ||
805 | xen_preemptible_hcall_begin(); | |
806 | rc = HYPERVISOR_memory_op(XENMEM_acquire_resource, &xdata); | |
807 | xen_preemptible_hcall_end(); | |
808 | ||
809 | if (rc) | |
810 | goto out; | |
811 | ||
812 | if (xen_feature(XENFEAT_auto_translated_physmap)) { | |
813 | struct remap_pfn r = { | |
814 | .mm = vma->vm_mm, | |
815 | .pages = vma->vm_private_data, | |
816 | .prot = vma->vm_page_prot, | |
817 | }; | |
818 | ||
819 | rc = apply_to_page_range(r.mm, kdata.addr, | |
820 | kdata.num << PAGE_SHIFT, | |
821 | remap_pfn_fn, &r); | |
822 | } else { | |
823 | unsigned int domid = | |
824 | (xdata.flags & XENMEM_rsrc_acq_caller_owned) ? | |
825 | DOMID_SELF : kdata.dom; | |
826 | int num; | |
827 | ||
828 | num = xen_remap_domain_mfn_array(vma, | |
829 | kdata.addr & PAGE_MASK, | |
830 | pfns, kdata.num, (int *)pfns, | |
831 | vma->vm_page_prot, | |
832 | domid, | |
833 | vma->vm_private_data); | |
834 | if (num < 0) | |
835 | rc = num; | |
836 | else if (num != kdata.num) { | |
837 | unsigned int i; | |
838 | ||
839 | for (i = 0; i < num; i++) { | |
840 | rc = pfns[i]; | |
841 | if (rc < 0) | |
842 | break; | |
843 | } | |
844 | } else | |
845 | rc = 0; | |
846 | } | |
847 | ||
848 | out: | |
849 | up_write(&mm->mmap_sem); | |
850 | kfree(pfns); | |
851 | ||
852 | return rc; | |
853 | } | |
854 | ||
1c5de193 JF |
855 | static long privcmd_ioctl(struct file *file, |
856 | unsigned int cmd, unsigned long data) | |
857 | { | |
dc9eab6f | 858 | int ret = -ENOTTY; |
1c5de193 JF |
859 | void __user *udata = (void __user *) data; |
860 | ||
861 | switch (cmd) { | |
862 | case IOCTL_PRIVCMD_HYPERCALL: | |
4610d240 | 863 | ret = privcmd_ioctl_hypercall(file, udata); |
1c5de193 JF |
864 | break; |
865 | ||
866 | case IOCTL_PRIVCMD_MMAP: | |
4610d240 | 867 | ret = privcmd_ioctl_mmap(file, udata); |
1c5de193 JF |
868 | break; |
869 | ||
870 | case IOCTL_PRIVCMD_MMAPBATCH: | |
4610d240 | 871 | ret = privcmd_ioctl_mmap_batch(file, udata, 1); |
ceb90fa0 ALC |
872 | break; |
873 | ||
874 | case IOCTL_PRIVCMD_MMAPBATCH_V2: | |
4610d240 | 875 | ret = privcmd_ioctl_mmap_batch(file, udata, 2); |
1c5de193 JF |
876 | break; |
877 | ||
ab520be8 | 878 | case IOCTL_PRIVCMD_DM_OP: |
4610d240 PD |
879 | ret = privcmd_ioctl_dm_op(file, udata); |
880 | break; | |
881 | ||
882 | case IOCTL_PRIVCMD_RESTRICT: | |
883 | ret = privcmd_ioctl_restrict(file, udata); | |
ab520be8 PD |
884 | break; |
885 | ||
3ad08765 PD |
886 | case IOCTL_PRIVCMD_MMAP_RESOURCE: |
887 | ret = privcmd_ioctl_mmap_resource(file, udata); | |
888 | break; | |
889 | ||
1c5de193 | 890 | default: |
1c5de193 JF |
891 | break; |
892 | } | |
893 | ||
894 | return ret; | |
895 | } | |
896 | ||
4610d240 PD |
897 | static int privcmd_open(struct inode *ino, struct file *file) |
898 | { | |
899 | struct privcmd_data *data = kzalloc(sizeof(*data), GFP_KERNEL); | |
900 | ||
901 | if (!data) | |
902 | return -ENOMEM; | |
903 | ||
904 | /* DOMID_INVALID implies no restriction */ | |
905 | data->domid = DOMID_INVALID; | |
906 | ||
907 | file->private_data = data; | |
908 | return 0; | |
909 | } | |
910 | ||
911 | static int privcmd_release(struct inode *ino, struct file *file) | |
912 | { | |
913 | struct privcmd_data *data = file->private_data; | |
914 | ||
915 | kfree(data); | |
916 | return 0; | |
917 | } | |
918 | ||
d71f5139 MR |
919 | static void privcmd_close(struct vm_area_struct *vma) |
920 | { | |
921 | struct page **pages = vma->vm_private_data; | |
c7ebf9d9 | 922 | int numpgs = vma_pages(vma); |
5995a68a | 923 | int numgfns = (vma->vm_end - vma->vm_start) >> XEN_PAGE_SHIFT; |
b6497b38 | 924 | int rc; |
d71f5139 | 925 | |
9eff37a8 | 926 | if (!xen_feature(XENFEAT_auto_translated_physmap) || !numpgs || !pages) |
d71f5139 MR |
927 | return; |
928 | ||
5995a68a | 929 | rc = xen_unmap_domain_gfn_range(vma, numgfns, pages); |
b6497b38 IC |
930 | if (rc == 0) |
931 | free_xenballooned_pages(numpgs, pages); | |
932 | else | |
933 | pr_crit("unable to unmap MFN range: leaking %d pages. rc=%d\n", | |
934 | numpgs, rc); | |
d71f5139 MR |
935 | kfree(pages); |
936 | } | |
937 | ||
4bf2cc96 | 938 | static vm_fault_t privcmd_fault(struct vm_fault *vmf) |
1c5de193 | 939 | { |
441c7416 | 940 | printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n", |
11bac800 | 941 | vmf->vma, vmf->vma->vm_start, vmf->vma->vm_end, |
1a29d85e | 942 | vmf->pgoff, (void *)vmf->address); |
441c7416 | 943 | |
1c5de193 JF |
944 | return VM_FAULT_SIGBUS; |
945 | } | |
946 | ||
7cbea8dc | 947 | static const struct vm_operations_struct privcmd_vm_ops = { |
d71f5139 | 948 | .close = privcmd_close, |
1c5de193 JF |
949 | .fault = privcmd_fault |
950 | }; | |
951 | ||
952 | static int privcmd_mmap(struct file *file, struct vm_area_struct *vma) | |
953 | { | |
e060e7af SS |
954 | /* DONTCOPY is essential for Xen because copy_page_range doesn't know |
955 | * how to recreate these mappings */ | |
314e51b9 KK |
956 | vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTCOPY | |
957 | VM_DONTEXPAND | VM_DONTDUMP; | |
1c5de193 JF |
958 | vma->vm_ops = &privcmd_vm_ops; |
959 | vma->vm_private_data = NULL; | |
960 | ||
961 | return 0; | |
962 | } | |
963 | ||
a5deabe0 ALC |
964 | /* |
965 | * For MMAPBATCH*. This allows asserting the singleshot mapping | |
966 | * on a per pfn/pte basis. Mapping calls that fail with ENOENT | |
967 | * can be then retried until success. | |
968 | */ | |
969 | static int is_mapped_fn(pte_t *pte, struct page *pmd_page, | |
970 | unsigned long addr, void *data) | |
971 | { | |
972 | return pte_none(*pte) ? 0 : -EBUSY; | |
973 | } | |
974 | ||
975 | static int privcmd_vma_range_is_mapped( | |
976 | struct vm_area_struct *vma, | |
977 | unsigned long addr, | |
978 | unsigned long nr_pages) | |
1c5de193 | 979 | { |
a5deabe0 ALC |
980 | return apply_to_page_range(vma->vm_mm, addr, nr_pages << PAGE_SHIFT, |
981 | is_mapped_fn, NULL) != 0; | |
1c5de193 | 982 | } |
1c5de193 | 983 | |
d8414d3c BB |
984 | const struct file_operations xen_privcmd_fops = { |
985 | .owner = THIS_MODULE, | |
1c5de193 | 986 | .unlocked_ioctl = privcmd_ioctl, |
4610d240 PD |
987 | .open = privcmd_open, |
988 | .release = privcmd_release, | |
1c5de193 JF |
989 | .mmap = privcmd_mmap, |
990 | }; | |
d8414d3c BB |
991 | EXPORT_SYMBOL_GPL(xen_privcmd_fops); |
992 | ||
993 | static struct miscdevice privcmd_dev = { | |
994 | .minor = MISC_DYNAMIC_MINOR, | |
995 | .name = "xen/privcmd", | |
996 | .fops = &xen_privcmd_fops, | |
997 | }; | |
998 | ||
999 | static int __init privcmd_init(void) | |
1000 | { | |
1001 | int err; | |
1002 | ||
1003 | if (!xen_domain()) | |
1004 | return -ENODEV; | |
1005 | ||
1006 | err = misc_register(&privcmd_dev); | |
1007 | if (err != 0) { | |
283c0972 | 1008 | pr_err("Could not register Xen privcmd device\n"); |
d8414d3c BB |
1009 | return err; |
1010 | } | |
c51b3c63 JG |
1011 | |
1012 | err = misc_register(&xen_privcmdbuf_dev); | |
1013 | if (err != 0) { | |
1014 | pr_err("Could not register Xen hypercall-buf device\n"); | |
1015 | misc_deregister(&privcmd_dev); | |
1016 | return err; | |
1017 | } | |
1018 | ||
d8414d3c BB |
1019 | return 0; |
1020 | } | |
1021 | ||
1022 | static void __exit privcmd_exit(void) | |
1023 | { | |
1024 | misc_deregister(&privcmd_dev); | |
c51b3c63 | 1025 | misc_deregister(&xen_privcmdbuf_dev); |
d8414d3c BB |
1026 | } |
1027 | ||
1028 | module_init(privcmd_init); | |
1029 | module_exit(privcmd_exit); |