blob: 5a296161d843baa5eda5282e15b198e6a6f69feb [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
David Vrabelfdfd8112015-02-19 15:23:17 +000059 xen_preemptible_hcall_begin();
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -080060 ret = privcmd_call(hypercall.op,
61 hypercall.arg[0], hypercall.arg[1],
62 hypercall.arg[2], hypercall.arg[3],
63 hypercall.arg[4]);
David Vrabelfdfd8112015-02-19 15:23:17 +000064 xen_preemptible_hcall_end();
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -080065
66 return ret;
67}
68
69static void free_page_list(struct list_head *pages)
70{
71 struct page *p, *n;
72
73 list_for_each_entry_safe(p, n, pages, lru)
74 __free_page(p);
75
76 INIT_LIST_HEAD(pages);
77}
78
79/*
80 * Given an array of items in userspace, return a list of pages
81 * containing the data. If copying fails, either because of memory
82 * allocation failure or a problem reading user memory, return an
83 * error code; its up to the caller to dispose of any partial list.
84 */
85static int gather_array(struct list_head *pagelist,
86 unsigned nelem, size_t size,
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -040087 const void __user *data)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -080088{
89 unsigned pageidx;
90 void *pagedata;
91 int ret;
92
93 if (size > PAGE_SIZE)
94 return 0;
95
96 pageidx = PAGE_SIZE;
97 pagedata = NULL; /* quiet, gcc */
98 while (nelem--) {
99 if (pageidx > PAGE_SIZE-size) {
100 struct page *page = alloc_page(GFP_KERNEL);
101
102 ret = -ENOMEM;
103 if (page == NULL)
104 goto fail;
105
106 pagedata = page_address(page);
107
108 list_add_tail(&page->lru, pagelist);
109 pageidx = 0;
110 }
111
112 ret = -EFAULT;
113 if (copy_from_user(pagedata + pageidx, data, size))
114 goto fail;
115
116 data += size;
117 pageidx += size;
118 }
119
120 ret = 0;
121
122fail:
123 return ret;
124}
125
126/*
127 * Call function "fn" on each element of the array fragmented
128 * over a list of pages.
129 */
130static int traverse_pages(unsigned nelem, size_t size,
131 struct list_head *pos,
132 int (*fn)(void *data, void *state),
133 void *state)
134{
135 void *pagedata;
136 unsigned pageidx;
Ian Campbellf020e292009-05-20 15:42:14 +0100137 int ret = 0;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800138
139 BUG_ON(size > PAGE_SIZE);
140
141 pageidx = PAGE_SIZE;
142 pagedata = NULL; /* hush, gcc */
143
144 while (nelem--) {
145 if (pageidx > PAGE_SIZE-size) {
146 struct page *page;
147 pos = pos->next;
148 page = list_entry(pos, struct page, lru);
149 pagedata = page_address(page);
150 pageidx = 0;
151 }
152
153 ret = (*fn)(pagedata + pageidx, state);
154 if (ret)
155 break;
156 pageidx += size;
157 }
158
159 return ret;
160}
161
David Vrabel4e8c0c82015-03-11 14:49:57 +0000162/*
163 * Similar to traverse_pages, but use each page as a "block" of
164 * data to be processed as one unit.
165 */
166static int traverse_pages_block(unsigned nelem, size_t size,
167 struct list_head *pos,
168 int (*fn)(void *data, int nr, void *state),
169 void *state)
170{
171 void *pagedata;
172 unsigned pageidx;
173 int ret = 0;
174
175 BUG_ON(size > PAGE_SIZE);
176
177 pageidx = PAGE_SIZE;
178
179 while (nelem) {
180 int nr = (PAGE_SIZE/size);
181 struct page *page;
182 if (nr > nelem)
183 nr = nelem;
184 pos = pos->next;
185 page = list_entry(pos, struct page, lru);
186 pagedata = page_address(page);
187 ret = (*fn)(pagedata, nr, state);
188 if (ret)
189 break;
190 nelem -= nr;
191 }
192
193 return ret;
194}
195
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800196struct mmap_mfn_state {
197 unsigned long va;
198 struct vm_area_struct *vma;
199 domid_t domain;
200};
201
202static int mmap_mfn_range(void *data, void *state)
203{
204 struct privcmd_mmap_entry *msg = data;
205 struct mmap_mfn_state *st = state;
206 struct vm_area_struct *vma = st->vma;
207 int rc;
208
209 /* Do not allow range to wrap the address space. */
210 if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) ||
211 ((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va))
212 return -EINVAL;
213
214 /* Range chunks must be contiguous in va space. */
215 if ((msg->va != st->va) ||
216 ((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end))
217 return -EINVAL;
218
Ian Campbellde1ef202009-05-21 10:09:46 +0100219 rc = xen_remap_domain_mfn_range(vma,
220 msg->va & PAGE_MASK,
221 msg->mfn, msg->npages,
222 vma->vm_page_prot,
Ian Campbell9a032e32012-10-17 13:37:49 -0700223 st->domain, NULL);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800224 if (rc < 0)
225 return rc;
226
227 st->va += msg->npages << PAGE_SHIFT;
228
229 return 0;
230}
231
232static long privcmd_ioctl_mmap(void __user *udata)
233{
234 struct privcmd_mmap mmapcmd;
235 struct mm_struct *mm = current->mm;
236 struct vm_area_struct *vma;
237 int rc;
238 LIST_HEAD(pagelist);
239 struct mmap_mfn_state state;
240
Mukesh Rathord71f5132012-10-17 17:11:21 -0700241 /* We only support privcmd_ioctl_mmap_batch for auto translated. */
242 if (xen_feature(XENFEAT_auto_translated_physmap))
243 return -ENOSYS;
244
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800245 if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd)))
246 return -EFAULT;
247
248 rc = gather_array(&pagelist,
249 mmapcmd.num, sizeof(struct privcmd_mmap_entry),
250 mmapcmd.entry);
251
252 if (rc || list_empty(&pagelist))
253 goto out;
254
255 down_write(&mm->mmap_sem);
256
257 {
258 struct page *page = list_first_entry(&pagelist,
259 struct page, lru);
260 struct privcmd_mmap_entry *msg = page_address(page);
261
262 vma = find_vma(mm, msg->va);
263 rc = -EINVAL;
264
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100265 if (!vma || (msg->va != vma->vm_start) || vma->vm_private_data)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800266 goto out_up;
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100267 vma->vm_private_data = PRIV_VMA_LOCKED;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800268 }
269
270 state.va = vma->vm_start;
271 state.vma = vma;
272 state.domain = mmapcmd.dom;
273
274 rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry),
275 &pagelist,
276 mmap_mfn_range, &state);
277
278
279out_up:
280 up_write(&mm->mmap_sem);
281
282out:
283 free_page_list(&pagelist);
284
285 return rc;
286}
287
288struct mmap_batch_state {
289 domid_t domain;
290 unsigned long va;
291 struct vm_area_struct *vma;
Mukesh Rathord71f5132012-10-17 17:11:21 -0700292 int index;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400293 /* A tristate:
294 * 0 for no errors
295 * 1 if at least one error has happened (and no
296 * -ENOENT errors have happened)
297 * -ENOENT if at least 1 -ENOENT has happened.
298 */
299 int global_error;
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500300 int version;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800301
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400302 /* User-space mfn array to store errors in the second pass for V1. */
303 xen_pfn_t __user *user_mfn;
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500304 /* User-space int array to store errors in the second pass for V2. */
305 int __user *user_err;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800306};
307
Mukesh Rathord71f5132012-10-17 17:11:21 -0700308/* auto translated dom0 note: if domU being created is PV, then mfn is
309 * mfn(addr on bus). If it's auto xlated, then mfn is pfn (input to HAP).
310 */
David Vrabel4e8c0c82015-03-11 14:49:57 +0000311static int mmap_batch_fn(void *data, int nr, void *state)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800312{
313 xen_pfn_t *mfnp = data;
314 struct mmap_batch_state *st = state;
Mukesh Rathord71f5132012-10-17 17:11:21 -0700315 struct vm_area_struct *vma = st->vma;
316 struct page **pages = vma->vm_private_data;
David Vrabel4e8c0c82015-03-11 14:49:57 +0000317 struct page **cur_pages = NULL;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400318 int ret;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800319
Mukesh Rathord71f5132012-10-17 17:11:21 -0700320 if (xen_feature(XENFEAT_auto_translated_physmap))
David Vrabel4e8c0c82015-03-11 14:49:57 +0000321 cur_pages = &pages[st->index];
Mukesh Rathord71f5132012-10-17 17:11:21 -0700322
David Vrabel4e8c0c82015-03-11 14:49:57 +0000323 BUG_ON(nr < 0);
324 ret = xen_remap_domain_mfn_array(st->vma, st->va & PAGE_MASK, mfnp, nr,
325 (int *)mfnp, st->vma->vm_page_prot,
326 st->domain, cur_pages);
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400327
David Vrabel4e8c0c82015-03-11 14:49:57 +0000328 /* Adjust the global_error? */
329 if (ret != nr) {
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400330 if (ret == -ENOENT)
331 st->global_error = -ENOENT;
332 else {
333 /* Record that at least one error has happened. */
334 if (st->global_error == 0)
335 st->global_error = 1;
336 }
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800337 }
David Vrabel4e8c0c82015-03-11 14:49:57 +0000338 st->va += PAGE_SIZE * nr;
339 st->index += nr;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800340
341 return 0;
342}
343
David Vrabel4e8c0c82015-03-11 14:49:57 +0000344static int mmap_return_error(int err, struct mmap_batch_state *st)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800345{
David Vrabel4e8c0c82015-03-11 14:49:57 +0000346 int ret;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800347
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500348 if (st->version == 1) {
David Vrabel4e8c0c82015-03-11 14:49:57 +0000349 if (err) {
350 xen_pfn_t mfn;
351
352 ret = get_user(mfn, st->user_mfn);
353 if (ret < 0)
354 return ret;
355 /*
356 * V1 encodes the error codes in the 32bit top
357 * nibble of the mfn (with its known
358 * limitations vis-a-vis 64 bit callers).
359 */
360 mfn |= (err == -ENOENT) ?
361 PRIVCMD_MMAPBATCH_PAGED_ERROR :
362 PRIVCMD_MMAPBATCH_MFN_ERROR;
363 return __put_user(mfn, st->user_mfn++);
364 } else
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500365 st->user_mfn++;
366 } else { /* st->version == 2 */
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500367 if (err)
368 return __put_user(err, st->user_err++);
369 else
370 st->user_err++;
371 }
372
373 return 0;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800374}
375
David Vrabel4e8c0c82015-03-11 14:49:57 +0000376static int mmap_return_errors(void *data, int nr, void *state)
377{
378 struct mmap_batch_state *st = state;
379 int *errs = data;
380 int i;
381 int ret;
382
383 for (i = 0; i < nr; i++) {
384 ret = mmap_return_error(errs[i], st);
385 if (ret < 0)
386 return ret;
387 }
388 return 0;
389}
390
Mukesh Rathord71f5132012-10-17 17:11:21 -0700391/* Allocate pfns that are then mapped with gmfns from foreign domid. Update
392 * the vma with the page info to use later.
393 * Returns: 0 if success, otherwise -errno
394 */
395static int alloc_empty_pages(struct vm_area_struct *vma, int numpgs)
396{
397 int rc;
398 struct page **pages;
399
400 pages = kcalloc(numpgs, sizeof(pages[0]), GFP_KERNEL);
401 if (pages == NULL)
402 return -ENOMEM;
403
404 rc = alloc_xenballooned_pages(numpgs, pages, 0);
405 if (rc != 0) {
406 pr_warn("%s Could not alloc %d pfns rc:%d\n", __func__,
407 numpgs, rc);
408 kfree(pages);
409 return -ENOMEM;
410 }
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100411 BUG_ON(vma->vm_private_data != NULL);
Mukesh Rathord71f5132012-10-17 17:11:21 -0700412 vma->vm_private_data = pages;
413
414 return 0;
415}
416
Jeremy Fitzhardingef31fdf52009-03-08 04:10:00 -0700417static struct vm_operations_struct privcmd_vm_ops;
418
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400419static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800420{
421 int ret;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400422 struct privcmd_mmapbatch_v2 m;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800423 struct mm_struct *mm = current->mm;
424 struct vm_area_struct *vma;
425 unsigned long nr_pages;
426 LIST_HEAD(pagelist);
427 struct mmap_batch_state state;
428
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400429 switch (version) {
430 case 1:
431 if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch)))
432 return -EFAULT;
433 /* Returns per-frame error in m.arr. */
434 m.err = NULL;
435 if (!access_ok(VERIFY_WRITE, m.arr, m.num * sizeof(*m.arr)))
436 return -EFAULT;
437 break;
438 case 2:
439 if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch_v2)))
440 return -EFAULT;
441 /* Returns per-frame error code in m.err. */
442 if (!access_ok(VERIFY_WRITE, m.err, m.num * (sizeof(*m.err))))
443 return -EFAULT;
444 break;
445 default:
446 return -EINVAL;
447 }
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800448
449 nr_pages = m.num;
450 if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT)))
451 return -EINVAL;
452
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400453 ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), m.arr);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800454
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400455 if (ret)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800456 goto out;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400457 if (list_empty(&pagelist)) {
458 ret = -EINVAL;
459 goto out;
460 }
461
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500462 if (version == 2) {
463 /* Zero error array now to only copy back actual errors. */
464 if (clear_user(m.err, sizeof(int) * m.num)) {
465 ret = -EFAULT;
466 goto out;
467 }
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400468 }
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800469
470 down_write(&mm->mmap_sem);
471
472 vma = find_vma(mm, m.addr);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800473 if (!vma ||
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100474 vma->vm_ops != &privcmd_vm_ops) {
Mats Petersson68fa9652012-11-16 18:36:49 +0000475 ret = -EINVAL;
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100476 goto out_unlock;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800477 }
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100478
479 /*
480 * Caller must either:
481 *
482 * Map the whole VMA range, which will also allocate all the
483 * pages required for the auto_translated_physmap case.
484 *
485 * Or
486 *
487 * Map unmapped holes left from a previous map attempt (e.g.,
488 * because those foreign frames were previously paged out).
489 */
490 if (vma->vm_private_data == NULL) {
491 if (m.addr != vma->vm_start ||
492 m.addr + (nr_pages << PAGE_SHIFT) != vma->vm_end) {
493 ret = -EINVAL;
494 goto out_unlock;
495 }
496 if (xen_feature(XENFEAT_auto_translated_physmap)) {
497 ret = alloc_empty_pages(vma, m.num);
498 if (ret < 0)
499 goto out_unlock;
500 } else
501 vma->vm_private_data = PRIV_VMA_LOCKED;
502 } else {
503 if (m.addr < vma->vm_start ||
504 m.addr + (nr_pages << PAGE_SHIFT) > vma->vm_end) {
505 ret = -EINVAL;
506 goto out_unlock;
507 }
508 if (privcmd_vma_range_is_mapped(vma, m.addr, nr_pages)) {
509 ret = -EINVAL;
510 goto out_unlock;
Mukesh Rathord71f5132012-10-17 17:11:21 -0700511 }
512 }
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800513
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400514 state.domain = m.dom;
515 state.vma = vma;
516 state.va = m.addr;
Mukesh Rathord71f5132012-10-17 17:11:21 -0700517 state.index = 0;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400518 state.global_error = 0;
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500519 state.version = version;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800520
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400521 /* mmap_batch_fn guarantees ret == 0 */
David Vrabel4e8c0c82015-03-11 14:49:57 +0000522 BUG_ON(traverse_pages_block(m.num, sizeof(xen_pfn_t),
523 &pagelist, mmap_batch_fn, &state));
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800524
525 up_write(&mm->mmap_sem);
526
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500527 if (state.global_error) {
528 /* Write back errors in second pass. */
529 state.user_mfn = (xen_pfn_t *)m.arr;
530 state.user_err = m.err;
David Vrabel4e8c0c82015-03-11 14:49:57 +0000531 ret = traverse_pages_block(m.num, sizeof(xen_pfn_t),
532 &pagelist, mmap_return_errors, &state);
Andres Lagar-Cavilla99beae62013-01-14 22:35:40 -0500533 } else
534 ret = 0;
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400535
536 /* If we have not had any EFAULT-like global errors then set the global
537 * error to -ENOENT if necessary. */
538 if ((ret == 0) && (state.global_error == -ENOENT))
539 ret = -ENOENT;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800540
541out:
542 free_page_list(&pagelist);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800543 return ret;
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100544
545out_unlock:
546 up_write(&mm->mmap_sem);
547 goto out;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800548}
549
550static long privcmd_ioctl(struct file *file,
551 unsigned int cmd, unsigned long data)
552{
553 int ret = -ENOSYS;
554 void __user *udata = (void __user *) data;
555
556 switch (cmd) {
557 case IOCTL_PRIVCMD_HYPERCALL:
558 ret = privcmd_ioctl_hypercall(udata);
559 break;
560
561 case IOCTL_PRIVCMD_MMAP:
562 ret = privcmd_ioctl_mmap(udata);
563 break;
564
565 case IOCTL_PRIVCMD_MMAPBATCH:
Andres Lagar-Cavillaceb90fa2012-08-31 09:59:30 -0400566 ret = privcmd_ioctl_mmap_batch(udata, 1);
567 break;
568
569 case IOCTL_PRIVCMD_MMAPBATCH_V2:
570 ret = privcmd_ioctl_mmap_batch(udata, 2);
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800571 break;
572
573 default:
574 ret = -EINVAL;
575 break;
576 }
577
578 return ret;
579}
580
Mukesh Rathord71f5132012-10-17 17:11:21 -0700581static void privcmd_close(struct vm_area_struct *vma)
582{
583 struct page **pages = vma->vm_private_data;
584 int numpgs = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
Ian Campbellb6497b32013-12-06 17:55:56 +0000585 int rc;
Mukesh Rathord71f5132012-10-17 17:11:21 -0700586
Dan Carpenter9eff37a2012-11-05 09:42:17 +0300587 if (!xen_feature(XENFEAT_auto_translated_physmap) || !numpgs || !pages)
Mukesh Rathord71f5132012-10-17 17:11:21 -0700588 return;
589
Ian Campbellb6497b32013-12-06 17:55:56 +0000590 rc = xen_unmap_domain_mfn_range(vma, numpgs, pages);
591 if (rc == 0)
592 free_xenballooned_pages(numpgs, pages);
593 else
594 pr_crit("unable to unmap MFN range: leaking %d pages. rc=%d\n",
595 numpgs, rc);
Mukesh Rathord71f5132012-10-17 17:11:21 -0700596 kfree(pages);
597}
598
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800599static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
600{
Jeremy Fitzhardinge441c7412009-03-06 09:56:59 -0800601 printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
602 vma, vma->vm_start, vma->vm_end,
603 vmf->pgoff, vmf->virtual_address);
604
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800605 return VM_FAULT_SIGBUS;
606}
607
608static struct vm_operations_struct privcmd_vm_ops = {
Mukesh Rathord71f5132012-10-17 17:11:21 -0700609 .close = privcmd_close,
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800610 .fault = privcmd_fault
611};
612
613static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
614{
Stefano Stabellinie060e7af2010-11-11 12:37:43 -0800615 /* DONTCOPY is essential for Xen because copy_page_range doesn't know
616 * how to recreate these mappings */
Konstantin Khlebnikov314e51b2012-10-08 16:29:02 -0700617 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTCOPY |
618 VM_DONTEXPAND | VM_DONTDUMP;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800619 vma->vm_ops = &privcmd_vm_ops;
620 vma->vm_private_data = NULL;
621
622 return 0;
623}
624
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100625/*
626 * For MMAPBATCH*. This allows asserting the singleshot mapping
627 * on a per pfn/pte basis. Mapping calls that fail with ENOENT
628 * can be then retried until success.
629 */
630static int is_mapped_fn(pte_t *pte, struct page *pmd_page,
631 unsigned long addr, void *data)
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800632{
Andres Lagar-Cavillaa5deabe2013-08-23 18:10:06 +0100633 return pte_none(*pte) ? 0 : -EBUSY;
634}
635
636static int privcmd_vma_range_is_mapped(
637 struct vm_area_struct *vma,
638 unsigned long addr,
639 unsigned long nr_pages)
640{
641 return apply_to_page_range(vma->vm_mm, addr, nr_pages << PAGE_SHIFT,
642 is_mapped_fn, NULL) != 0;
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800643}
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800644
Bastian Blankd8414d32011-12-16 11:34:33 -0500645const struct file_operations xen_privcmd_fops = {
646 .owner = THIS_MODULE,
Jeremy Fitzhardinge1c5de192009-02-09 12:05:49 -0800647 .unlocked_ioctl = privcmd_ioctl,
648 .mmap = privcmd_mmap,
649};
Bastian Blankd8414d32011-12-16 11:34:33 -0500650EXPORT_SYMBOL_GPL(xen_privcmd_fops);
651
652static struct miscdevice privcmd_dev = {
653 .minor = MISC_DYNAMIC_MINOR,
654 .name = "xen/privcmd",
655 .fops = &xen_privcmd_fops,
656};
657
658static int __init privcmd_init(void)
659{
660 int err;
661
662 if (!xen_domain())
663 return -ENODEV;
664
665 err = misc_register(&privcmd_dev);
666 if (err != 0) {
Joe Perches283c0972013-06-28 03:21:41 -0700667 pr_err("Could not register Xen privcmd device\n");
Bastian Blankd8414d32011-12-16 11:34:33 -0500668 return err;
669 }
670 return 0;
671}
672
673static void __exit privcmd_exit(void)
674{
675 misc_deregister(&privcmd_dev);
676}
677
678module_init(privcmd_init);
679module_exit(privcmd_exit);