blob: 569a13b9e856de5c3900050d583844f401243e96 [file] [log] [blame]
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -08001/******************************************************************************
2 * privcmd.c
3 *
4 * Interface to privileged domain-0 commands.
5 *
6 * Copyright (c) 2002-2004, K A Fraser, B Dragovic
7 */
8
Joe Perches283c0972013-06-28 03:21:41 -07009#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
10
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -080011#include <linux/kernel.h>
Bastian Blankd8414d32011-12-16 11:34:33 -050012#include <linux/module.h>
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -080013#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>
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -080021#include <linux/highmem.h>
22#include <linux/pagemap.h>
23#include <linux/seq_file.h>
Bastian Blankd8414d32011-12-16 11:34:33 -050024#include <linux/miscdevice.h>
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -080025
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>
Ian Campbellde1ef202009-05-21 10:09:46 +010037#include <xen/xen-ops.h>
Mukesh Rathord71f5132012-10-17 17:11:21 -070038#include <xen/balloon.h>
Ian Campbellf020e292009-05-20 15:42:14 +010039
Bastian Blankd8414d32011-12-16 11:34:33 -050040#include "privcmd.h"
41
42MODULE_LICENSE("GPL");
43
Mukesh Rathord71f5132012-10-17 17:11:21 -070044#define PRIV_VMA_LOCKED ((void *)1)
45
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +010046static int privcmd_vma_range_is_mapped(
47 struct vm_area_struct *vma,
48 unsigned long addr,
49 unsigned long nr_pages);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -080050
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -080051static 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
67static 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 */
83static int gather_array(struct list_head *pagelist,
84 unsigned nelem, size_t size,
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -040085 const void __user *data)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -080086{
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
120fail:
121 return ret;
122}
123
124/*
125 * Call function "fn" on each element of the array fragmented
126 * over a list of pages.
127 */
128static 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;
Ian Campbellf020e292009-05-20 15:42:14 +0100135 int ret = 0;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800136
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
160struct mmap_mfn_state {
161 unsigned long va;
162 struct vm_area_struct *vma;
163 domid_t domain;
164};
165
166static 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
Ian Campbellde1ef202009-05-21 10:09:46 +0100183 rc = xen_remap_domain_mfn_range(vma,
184 msg->va & PAGE_MASK,
185 msg->mfn, msg->npages,
186 vma->vm_page_prot,
Ian Campbell9a032e32012-10-17 13:37:49 -0700187 st->domain, NULL);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800188 if (rc < 0)
189 return rc;
190
191 st->va += msg->npages << PAGE_SHIFT;
192
193 return 0;
194}
195
196static 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
Mukesh Rathord71f5132012-10-17 17:11:21 -0700205 /* We only support privcmd_ioctl_mmap_batch for auto translated. */
206 if (xen_feature(XENFEAT_auto_translated_physmap))
207 return -ENOSYS;
208
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800209 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
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100229 if (!vma || (msg->va != vma->vm_start) || vma->vm_private_data)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800230 goto out_up;
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100231 vma->vm_private_data = PRIV_VMA_LOCKED;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800232 }
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
243out_up:
244 up_write(&mm->mmap_sem);
245
246out:
247 free_page_list(&pagelist);
248
249 return rc;
250}
251
252struct mmap_batch_state {
253 domid_t domain;
254 unsigned long va;
255 struct vm_area_struct *vma;
Mukesh Rathord71f5132012-10-17 17:11:21 -0700256 int index;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400257 /* 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;
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500264 int version;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800265
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400266 /* User-space mfn array to store errors in the second pass for V1. */
267 xen_pfn_t __user *user_mfn;
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500268 /* User-space int array to store errors in the second pass for V2. */
269 int __user *user_err;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800270};
271
Mukesh Rathord71f5132012-10-17 17:11:21 -0700272/* 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 */
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800275static int mmap_batch_fn(void *data, void *state)
276{
277 xen_pfn_t *mfnp = data;
278 struct mmap_batch_state *st = state;
Mukesh Rathord71f5132012-10-17 17:11:21 -0700279 struct vm_area_struct *vma = st->vma;
280 struct page **pages = vma->vm_private_data;
281 struct page *cur_page = NULL;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400282 int ret;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800283
Mukesh Rathord71f5132012-10-17 17:11:21 -0700284 if (xen_feature(XENFEAT_auto_translated_physmap))
285 cur_page = pages[st->index++];
286
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400287 ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
Ian Campbell9a032e32012-10-17 13:37:49 -0700288 st->vma->vm_page_prot, st->domain,
Mukesh Rathord71f5132012-10-17 17:11:21 -0700289 &cur_page);
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400290
291 /* Store error code for second pass. */
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500292 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 }
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400305
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 }
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800315 }
316 st->va += PAGE_SIZE;
317
318 return 0;
319}
320
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500321static int mmap_return_errors(void *data, void *state)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800322{
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800323 struct mmap_batch_state *st = state;
324
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500325 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;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800340}
341
Mukesh Rathord71f5132012-10-17 17:11:21 -0700342/* 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 */
346static 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 }
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100362 BUG_ON(vma->vm_private_data != NULL);
Mukesh Rathord71f5132012-10-17 17:11:21 -0700363 vma->vm_private_data = pages;
364
365 return 0;
366}
367
Jeremy Fitzhardingef31fdf52009-03-08 04:10:00 -0700368static struct vm_operations_struct privcmd_vm_ops;
369
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400370static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800371{
372 int ret;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400373 struct privcmd_mmapbatch_v2 m;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800374 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
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400380 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 }
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800399
400 nr_pages = m.num;
401 if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT)))
402 return -EINVAL;
403
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400404 ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), m.arr);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800405
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400406 if (ret)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800407 goto out;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400408 if (list_empty(&pagelist)) {
409 ret = -EINVAL;
410 goto out;
411 }
412
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500413 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 }
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400419 }
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800420
421 down_write(&mm->mmap_sem);
422
423 vma = find_vma(mm, m.addr);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800424 if (!vma ||
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100425 vma->vm_ops != &privcmd_vm_ops) {
Mats Petersson68fa9652012-11-16 18:36:49 +0000426 ret = -EINVAL;
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100427 goto out_unlock;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800428 }
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100429
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;
Mukesh Rathord71f5132012-10-17 17:11:21 -0700462 }
463 }
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800464
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400465 state.domain = m.dom;
466 state.vma = vma;
467 state.va = m.addr;
Mukesh Rathord71f5132012-10-17 17:11:21 -0700468 state.index = 0;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400469 state.global_error = 0;
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500470 state.version = version;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800471
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400472 /* mmap_batch_fn guarantees ret == 0 */
473 BUG_ON(traverse_pages(m.num, sizeof(xen_pfn_t),
474 &pagelist, mmap_batch_fn, &state));
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800475
476 up_write(&mm->mmap_sem);
477
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500478 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;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400486
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;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800491
492out:
493 free_page_list(&pagelist);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800494 return ret;
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100495
496out_unlock:
497 up_write(&mm->mmap_sem);
498 goto out;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800499}
500
501static 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:
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400517 ret = privcmd_ioctl_mmap_batch(udata, 1);
518 break;
519
520 case IOCTL_PRIVCMD_MMAPBATCH_V2:
521 ret = privcmd_ioctl_mmap_batch(udata, 2);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800522 break;
523
524 default:
525 ret = -EINVAL;
526 break;
527 }
528
529 return ret;
530}
531
Mukesh Rathord71f5132012-10-17 17:11:21 -0700532static 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;
Ian Campbellb6497b32013-12-06 17:55:56 +0000536 int rc;
Mukesh Rathord71f5132012-10-17 17:11:21 -0700537
Dan Carpenter9eff37a2012-11-05 09:42:17 +0300538 if (!xen_feature(XENFEAT_auto_translated_physmap) || !numpgs || !pages)
Mukesh Rathord71f5132012-10-17 17:11:21 -0700539 return;
540
Ian Campbellb6497b32013-12-06 17:55:56 +0000541 rc = xen_unmap_domain_mfn_range(vma, numpgs, pages);
542 if (rc == 0)
543 free_xenballooned_pages(numpgs, pages);
544 else
545 pr_crit("unable to unmap MFN range: leaking %d pages. rc=%d\n",
546 numpgs, rc);
Mukesh Rathord71f5132012-10-17 17:11:21 -0700547 kfree(pages);
548}
549
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800550static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
551{
Jeremy Fitzhardinge441c7412009-03-06 09:56:59 -0800552 printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
553 vma, vma->vm_start, vma->vm_end,
554 vmf->pgoff, vmf->virtual_address);
555
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800556 return VM_FAULT_SIGBUS;
557}
558
559static struct vm_operations_struct privcmd_vm_ops = {
Mukesh Rathord71f5132012-10-17 17:11:21 -0700560 .close = privcmd_close,
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800561 .fault = privcmd_fault
562};
563
564static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
565{
Stefano Stabellinie060e7af2010-11-11 12:37:43 -0800566 /* DONTCOPY is essential for Xen because copy_page_range doesn't know
567 * how to recreate these mappings */
Konstantin Khlebnikov314e51b2012-10-08 16:29:02 -0700568 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTCOPY |
569 VM_DONTEXPAND | VM_DONTDUMP;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800570 vma->vm_ops = &privcmd_vm_ops;
571 vma->vm_private_data = NULL;
572
573 return 0;
574}
575
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100576/*
577 * For MMAPBATCH*. This allows asserting the singleshot mapping
578 * on a per pfn/pte basis. Mapping calls that fail with ENOENT
579 * can be then retried until success.
580 */
581static int is_mapped_fn(pte_t *pte, struct page *pmd_page,
582 unsigned long addr, void *data)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800583{
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100584 return pte_none(*pte) ? 0 : -EBUSY;
585}
586
587static int privcmd_vma_range_is_mapped(
588 struct vm_area_struct *vma,
589 unsigned long addr,
590 unsigned long nr_pages)
591{
592 return apply_to_page_range(vma->vm_mm, addr, nr_pages << PAGE_SHIFT,
593 is_mapped_fn, NULL) != 0;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800594}
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800595
Bastian Blankd8414d32011-12-16 11:34:33 -0500596const struct file_operations xen_privcmd_fops = {
597 .owner = THIS_MODULE,
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800598 .unlocked_ioctl = privcmd_ioctl,
599 .mmap = privcmd_mmap,
600};
Bastian Blankd8414d32011-12-16 11:34:33 -0500601EXPORT_SYMBOL_GPL(xen_privcmd_fops);
602
603static struct miscdevice privcmd_dev = {
604 .minor = MISC_DYNAMIC_MINOR,
605 .name = "xen/privcmd",
606 .fops = &xen_privcmd_fops,
607};
608
609static int __init privcmd_init(void)
610{
611 int err;
612
613 if (!xen_domain())
614 return -ENODEV;
615
616 err = misc_register(&privcmd_dev);
617 if (err != 0) {
Joe Perches283c0972013-06-28 03:21:41 -0700618 pr_err("Could not register Xen privcmd device\n");
Bastian Blankd8414d32011-12-16 11:34:33 -0500619 return err;
620 }
621 return 0;
622}
623
624static void __exit privcmd_exit(void)
625{
626 misc_deregister(&privcmd_dev);
627}
628
629module_init(privcmd_init);
630module_exit(privcmd_exit);