Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 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 | |
| 9 | #include <linux/kernel.h> |
| 10 | #include <linux/sched.h> |
| 11 | #include <linux/slab.h> |
| 12 | #include <linux/string.h> |
| 13 | #include <linux/errno.h> |
| 14 | #include <linux/mm.h> |
| 15 | #include <linux/mman.h> |
| 16 | #include <linux/uaccess.h> |
| 17 | #include <linux/swap.h> |
| 18 | #include <linux/smp_lock.h> |
| 19 | #include <linux/highmem.h> |
| 20 | #include <linux/pagemap.h> |
| 21 | #include <linux/seq_file.h> |
| 22 | |
| 23 | #include <asm/pgalloc.h> |
| 24 | #include <asm/pgtable.h> |
| 25 | #include <asm/tlb.h> |
| 26 | #include <asm/xen/hypervisor.h> |
| 27 | #include <asm/xen/hypercall.h> |
| 28 | |
| 29 | #include <xen/xen.h> |
| 30 | #include <xen/privcmd.h> |
| 31 | #include <xen/interface/xen.h> |
| 32 | #include <xen/features.h> |
| 33 | #include <xen/page.h> |
| 34 | |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 35 | #define REMAP_BATCH_SIZE 16 |
| 36 | |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 37 | #ifndef HAVE_ARCH_PRIVCMD_MMAP |
| 38 | static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma); |
| 39 | #endif |
| 40 | |
| 41 | struct remap_data { |
| 42 | unsigned long mfn; |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 43 | pgprot_t prot; |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 44 | struct mmu_update *mmu_update; |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 45 | }; |
| 46 | |
| 47 | static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token, |
| 48 | unsigned long addr, void *data) |
| 49 | { |
| 50 | struct remap_data *rmd = data; |
| 51 | pte_t pte = pte_mkspecial(pfn_pte(rmd->mfn++, rmd->prot)); |
| 52 | |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 53 | rmd->mmu_update->ptr = arbitrary_virt_to_machine(ptep).maddr; |
| 54 | rmd->mmu_update->val = pte_val_ma(pte); |
| 55 | rmd->mmu_update++; |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 56 | |
| 57 | return 0; |
| 58 | } |
| 59 | |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 60 | static int remap_domain_mfn_range(struct vm_area_struct *vma, |
| 61 | unsigned long addr, |
| 62 | unsigned long mfn, int nr, |
| 63 | pgprot_t prot, unsigned domid) |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 64 | { |
| 65 | struct remap_data rmd; |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 66 | struct mmu_update mmu_update[REMAP_BATCH_SIZE]; |
| 67 | int batch; |
| 68 | unsigned long range; |
| 69 | int err = 0; |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 70 | |
| 71 | prot = __pgprot(pgprot_val(prot) | _PAGE_IOMAP); |
| 72 | |
| 73 | vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; |
| 74 | |
| 75 | rmd.mfn = mfn; |
| 76 | rmd.prot = prot; |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 77 | |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 78 | while (nr) { |
| 79 | batch = min(REMAP_BATCH_SIZE, nr); |
| 80 | range = (unsigned long)batch << PAGE_SHIFT; |
| 81 | |
| 82 | rmd.mmu_update = mmu_update; |
| 83 | err = apply_to_page_range(vma->vm_mm, addr, range, |
| 84 | remap_area_mfn_pte_fn, &rmd); |
| 85 | if (err) |
| 86 | goto out; |
| 87 | |
| 88 | err = -EFAULT; |
| 89 | if (HYPERVISOR_mmu_update(mmu_update, batch, NULL, domid) < 0) |
| 90 | goto out; |
| 91 | |
| 92 | nr -= batch; |
| 93 | addr += range; |
| 94 | } |
| 95 | |
| 96 | err = 0; |
| 97 | out: |
| 98 | |
| 99 | flush_tlb_all(); |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 100 | |
| 101 | return err; |
| 102 | } |
| 103 | |
| 104 | static long privcmd_ioctl_hypercall(void __user *udata) |
| 105 | { |
| 106 | struct privcmd_hypercall hypercall; |
| 107 | long ret; |
| 108 | |
| 109 | if (copy_from_user(&hypercall, udata, sizeof(hypercall))) |
| 110 | return -EFAULT; |
| 111 | |
| 112 | ret = privcmd_call(hypercall.op, |
| 113 | hypercall.arg[0], hypercall.arg[1], |
| 114 | hypercall.arg[2], hypercall.arg[3], |
| 115 | hypercall.arg[4]); |
| 116 | |
| 117 | return ret; |
| 118 | } |
| 119 | |
| 120 | static void free_page_list(struct list_head *pages) |
| 121 | { |
| 122 | struct page *p, *n; |
| 123 | |
| 124 | list_for_each_entry_safe(p, n, pages, lru) |
| 125 | __free_page(p); |
| 126 | |
| 127 | INIT_LIST_HEAD(pages); |
| 128 | } |
| 129 | |
| 130 | /* |
| 131 | * Given an array of items in userspace, return a list of pages |
| 132 | * containing the data. If copying fails, either because of memory |
| 133 | * allocation failure or a problem reading user memory, return an |
| 134 | * error code; its up to the caller to dispose of any partial list. |
| 135 | */ |
| 136 | static int gather_array(struct list_head *pagelist, |
| 137 | unsigned nelem, size_t size, |
| 138 | void __user *data) |
| 139 | { |
| 140 | unsigned pageidx; |
| 141 | void *pagedata; |
| 142 | int ret; |
| 143 | |
| 144 | if (size > PAGE_SIZE) |
| 145 | return 0; |
| 146 | |
| 147 | pageidx = PAGE_SIZE; |
| 148 | pagedata = NULL; /* quiet, gcc */ |
| 149 | while (nelem--) { |
| 150 | if (pageidx > PAGE_SIZE-size) { |
| 151 | struct page *page = alloc_page(GFP_KERNEL); |
| 152 | |
| 153 | ret = -ENOMEM; |
| 154 | if (page == NULL) |
| 155 | goto fail; |
| 156 | |
| 157 | pagedata = page_address(page); |
| 158 | |
| 159 | list_add_tail(&page->lru, pagelist); |
| 160 | pageidx = 0; |
| 161 | } |
| 162 | |
| 163 | ret = -EFAULT; |
| 164 | if (copy_from_user(pagedata + pageidx, data, size)) |
| 165 | goto fail; |
| 166 | |
| 167 | data += size; |
| 168 | pageidx += size; |
| 169 | } |
| 170 | |
| 171 | ret = 0; |
| 172 | |
| 173 | fail: |
| 174 | return ret; |
| 175 | } |
| 176 | |
| 177 | /* |
| 178 | * Call function "fn" on each element of the array fragmented |
| 179 | * over a list of pages. |
| 180 | */ |
| 181 | static int traverse_pages(unsigned nelem, size_t size, |
| 182 | struct list_head *pos, |
| 183 | int (*fn)(void *data, void *state), |
| 184 | void *state) |
| 185 | { |
| 186 | void *pagedata; |
| 187 | unsigned pageidx; |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 188 | int ret = 0; |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 189 | |
| 190 | BUG_ON(size > PAGE_SIZE); |
| 191 | |
| 192 | pageidx = PAGE_SIZE; |
| 193 | pagedata = NULL; /* hush, gcc */ |
| 194 | |
| 195 | while (nelem--) { |
| 196 | if (pageidx > PAGE_SIZE-size) { |
| 197 | struct page *page; |
| 198 | pos = pos->next; |
| 199 | page = list_entry(pos, struct page, lru); |
| 200 | pagedata = page_address(page); |
| 201 | pageidx = 0; |
| 202 | } |
| 203 | |
| 204 | ret = (*fn)(pagedata + pageidx, state); |
| 205 | if (ret) |
| 206 | break; |
| 207 | pageidx += size; |
| 208 | } |
| 209 | |
| 210 | return ret; |
| 211 | } |
| 212 | |
| 213 | struct mmap_mfn_state { |
| 214 | unsigned long va; |
| 215 | struct vm_area_struct *vma; |
| 216 | domid_t domain; |
| 217 | }; |
| 218 | |
| 219 | static int mmap_mfn_range(void *data, void *state) |
| 220 | { |
| 221 | struct privcmd_mmap_entry *msg = data; |
| 222 | struct mmap_mfn_state *st = state; |
| 223 | struct vm_area_struct *vma = st->vma; |
| 224 | int rc; |
| 225 | |
| 226 | /* Do not allow range to wrap the address space. */ |
| 227 | if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) || |
| 228 | ((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va)) |
| 229 | return -EINVAL; |
| 230 | |
| 231 | /* Range chunks must be contiguous in va space. */ |
| 232 | if ((msg->va != st->va) || |
| 233 | ((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end)) |
| 234 | return -EINVAL; |
| 235 | |
| 236 | rc = remap_domain_mfn_range(vma, |
| 237 | msg->va & PAGE_MASK, |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 238 | msg->mfn, msg->npages, |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 239 | vma->vm_page_prot, |
| 240 | st->domain); |
| 241 | if (rc < 0) |
| 242 | return rc; |
| 243 | |
| 244 | st->va += msg->npages << PAGE_SHIFT; |
| 245 | |
| 246 | return 0; |
| 247 | } |
| 248 | |
| 249 | static long privcmd_ioctl_mmap(void __user *udata) |
| 250 | { |
| 251 | struct privcmd_mmap mmapcmd; |
| 252 | struct mm_struct *mm = current->mm; |
| 253 | struct vm_area_struct *vma; |
| 254 | int rc; |
| 255 | LIST_HEAD(pagelist); |
| 256 | struct mmap_mfn_state state; |
| 257 | |
| 258 | if (!xen_initial_domain()) |
| 259 | return -EPERM; |
| 260 | |
| 261 | if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd))) |
| 262 | return -EFAULT; |
| 263 | |
| 264 | rc = gather_array(&pagelist, |
| 265 | mmapcmd.num, sizeof(struct privcmd_mmap_entry), |
| 266 | mmapcmd.entry); |
| 267 | |
| 268 | if (rc || list_empty(&pagelist)) |
| 269 | goto out; |
| 270 | |
| 271 | down_write(&mm->mmap_sem); |
| 272 | |
| 273 | { |
| 274 | struct page *page = list_first_entry(&pagelist, |
| 275 | struct page, lru); |
| 276 | struct privcmd_mmap_entry *msg = page_address(page); |
| 277 | |
| 278 | vma = find_vma(mm, msg->va); |
| 279 | rc = -EINVAL; |
| 280 | |
| 281 | if (!vma || (msg->va != vma->vm_start) || |
| 282 | !privcmd_enforce_singleshot_mapping(vma)) |
| 283 | goto out_up; |
| 284 | } |
| 285 | |
| 286 | state.va = vma->vm_start; |
| 287 | state.vma = vma; |
| 288 | state.domain = mmapcmd.dom; |
| 289 | |
| 290 | rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry), |
| 291 | &pagelist, |
| 292 | mmap_mfn_range, &state); |
| 293 | |
| 294 | |
| 295 | out_up: |
| 296 | up_write(&mm->mmap_sem); |
| 297 | |
| 298 | out: |
| 299 | free_page_list(&pagelist); |
| 300 | |
| 301 | return rc; |
| 302 | } |
| 303 | |
| 304 | struct mmap_batch_state { |
| 305 | domid_t domain; |
| 306 | unsigned long va; |
| 307 | struct vm_area_struct *vma; |
| 308 | int err; |
| 309 | |
| 310 | xen_pfn_t __user *user; |
| 311 | }; |
| 312 | |
| 313 | static int mmap_batch_fn(void *data, void *state) |
| 314 | { |
| 315 | xen_pfn_t *mfnp = data; |
| 316 | struct mmap_batch_state *st = state; |
| 317 | |
| 318 | if (remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 319 | *mfnp, 1, |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 320 | st->vma->vm_page_prot, st->domain) < 0) { |
| 321 | *mfnp |= 0xf0000000U; |
| 322 | st->err++; |
| 323 | } |
| 324 | st->va += PAGE_SIZE; |
| 325 | |
| 326 | return 0; |
| 327 | } |
| 328 | |
| 329 | static int mmap_return_errors(void *data, void *state) |
| 330 | { |
| 331 | xen_pfn_t *mfnp = data; |
| 332 | struct mmap_batch_state *st = state; |
| 333 | |
| 334 | put_user(*mfnp, st->user++); |
| 335 | |
| 336 | return 0; |
| 337 | } |
| 338 | |
Jeremy Fitzhardinge | f31fdf5 | 2009-03-08 04:10:00 -0700 | [diff] [blame] | 339 | static struct vm_operations_struct privcmd_vm_ops; |
| 340 | |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 341 | static long privcmd_ioctl_mmap_batch(void __user *udata) |
| 342 | { |
| 343 | int ret; |
| 344 | struct privcmd_mmapbatch m; |
| 345 | struct mm_struct *mm = current->mm; |
| 346 | struct vm_area_struct *vma; |
| 347 | unsigned long nr_pages; |
| 348 | LIST_HEAD(pagelist); |
| 349 | struct mmap_batch_state state; |
| 350 | |
| 351 | if (!xen_initial_domain()) |
| 352 | return -EPERM; |
| 353 | |
| 354 | if (copy_from_user(&m, udata, sizeof(m))) |
| 355 | return -EFAULT; |
| 356 | |
| 357 | nr_pages = m.num; |
| 358 | if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT))) |
| 359 | return -EINVAL; |
| 360 | |
| 361 | ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), |
| 362 | m.arr); |
| 363 | |
| 364 | if (ret || list_empty(&pagelist)) |
| 365 | goto out; |
| 366 | |
| 367 | down_write(&mm->mmap_sem); |
| 368 | |
| 369 | vma = find_vma(mm, m.addr); |
| 370 | ret = -EINVAL; |
| 371 | if (!vma || |
Jeremy Fitzhardinge | f31fdf5 | 2009-03-08 04:10:00 -0700 | [diff] [blame] | 372 | vma->vm_ops != &privcmd_vm_ops || |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 373 | (m.addr != vma->vm_start) || |
| 374 | ((m.addr + (nr_pages << PAGE_SHIFT)) != vma->vm_end) || |
| 375 | !privcmd_enforce_singleshot_mapping(vma)) { |
| 376 | up_write(&mm->mmap_sem); |
| 377 | goto out; |
| 378 | } |
| 379 | |
| 380 | state.domain = m.dom; |
| 381 | state.vma = vma; |
| 382 | state.va = m.addr; |
| 383 | state.err = 0; |
| 384 | |
| 385 | ret = traverse_pages(m.num, sizeof(xen_pfn_t), |
| 386 | &pagelist, mmap_batch_fn, &state); |
| 387 | |
| 388 | up_write(&mm->mmap_sem); |
| 389 | |
| 390 | if (state.err > 0) { |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 391 | ret = 0; |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 392 | |
Ian Campbell | f020e29 | 2009-05-20 15:42:14 +0100 | [diff] [blame^] | 393 | state.user = m.arr; |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 394 | traverse_pages(m.num, sizeof(xen_pfn_t), |
| 395 | &pagelist, |
| 396 | mmap_return_errors, &state); |
| 397 | } |
| 398 | |
| 399 | out: |
| 400 | free_page_list(&pagelist); |
| 401 | |
| 402 | return ret; |
| 403 | } |
| 404 | |
| 405 | static long privcmd_ioctl(struct file *file, |
| 406 | unsigned int cmd, unsigned long data) |
| 407 | { |
| 408 | int ret = -ENOSYS; |
| 409 | void __user *udata = (void __user *) data; |
| 410 | |
| 411 | switch (cmd) { |
| 412 | case IOCTL_PRIVCMD_HYPERCALL: |
| 413 | ret = privcmd_ioctl_hypercall(udata); |
| 414 | break; |
| 415 | |
| 416 | case IOCTL_PRIVCMD_MMAP: |
| 417 | ret = privcmd_ioctl_mmap(udata); |
| 418 | break; |
| 419 | |
| 420 | case IOCTL_PRIVCMD_MMAPBATCH: |
| 421 | ret = privcmd_ioctl_mmap_batch(udata); |
| 422 | break; |
| 423 | |
| 424 | default: |
| 425 | ret = -EINVAL; |
| 426 | break; |
| 427 | } |
| 428 | |
| 429 | return ret; |
| 430 | } |
| 431 | |
| 432 | #ifndef HAVE_ARCH_PRIVCMD_MMAP |
| 433 | static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
| 434 | { |
Jeremy Fitzhardinge | 441c741 | 2009-03-06 09:56:59 -0800 | [diff] [blame] | 435 | printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n", |
| 436 | vma, vma->vm_start, vma->vm_end, |
| 437 | vmf->pgoff, vmf->virtual_address); |
| 438 | |
Jeremy Fitzhardinge | 1c5de19 | 2009-02-09 12:05:49 -0800 | [diff] [blame] | 439 | return VM_FAULT_SIGBUS; |
| 440 | } |
| 441 | |
| 442 | static struct vm_operations_struct privcmd_vm_ops = { |
| 443 | .fault = privcmd_fault |
| 444 | }; |
| 445 | |
| 446 | static int privcmd_mmap(struct file *file, struct vm_area_struct *vma) |
| 447 | { |
| 448 | /* Unsupported for auto-translate guests. */ |
| 449 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
| 450 | return -ENOSYS; |
| 451 | |
| 452 | /* DONTCOPY is essential for Xen as copy_page_range is broken. */ |
| 453 | vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY; |
| 454 | vma->vm_ops = &privcmd_vm_ops; |
| 455 | vma->vm_private_data = NULL; |
| 456 | |
| 457 | return 0; |
| 458 | } |
| 459 | |
| 460 | static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma) |
| 461 | { |
| 462 | return (xchg(&vma->vm_private_data, (void *)1) == NULL); |
| 463 | } |
| 464 | #endif |
| 465 | |
| 466 | const struct file_operations privcmd_file_ops = { |
| 467 | .unlocked_ioctl = privcmd_ioctl, |
| 468 | .mmap = privcmd_mmap, |
| 469 | }; |