1 /* 2 * Copyright (c) 2014 Roger Pau Monné <roger.pau@citrix.com> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/param.h> 28 #include <sys/systm.h> 29 #include <sys/uio.h> 30 #include <sys/bus.h> 31 #include <sys/malloc.h> 32 #include <sys/kernel.h> 33 #include <sys/lock.h> 34 #include <sys/mutex.h> 35 #include <sys/rwlock.h> 36 #include <sys/selinfo.h> 37 #include <sys/poll.h> 38 #include <sys/conf.h> 39 #include <sys/fcntl.h> 40 #include <sys/ioccom.h> 41 #include <sys/rman.h> 42 #include <sys/tree.h> 43 #include <sys/module.h> 44 #include <sys/proc.h> 45 #include <sys/bitset.h> 46 47 #include <vm/vm.h> 48 #include <vm/vm_param.h> 49 #include <vm/vm_extern.h> 50 #include <vm/vm_kern.h> 51 #include <vm/vm_page.h> 52 #include <vm/vm_map.h> 53 #include <vm/vm_object.h> 54 #include <vm/vm_pager.h> 55 56 #include <machine/md_var.h> 57 58 #include <xen/xen-os.h> 59 #include <xen/hypervisor.h> 60 #include <xen/privcmd.h> 61 #include <xen/error.h> 62 63 MALLOC_DEFINE(M_PRIVCMD, "privcmd_dev", "Xen privcmd user-space device"); 64 65 #define MAX_DMOP_BUFFERS 16 66 67 struct privcmd_map { 68 vm_object_t mem; 69 vm_size_t size; 70 struct resource *pseudo_phys_res; 71 int pseudo_phys_res_id; 72 vm_paddr_t phys_base_addr; 73 boolean_t mapped; 74 BITSET_DEFINE_VAR() *err; 75 }; 76 77 static d_ioctl_t privcmd_ioctl; 78 static d_open_t privcmd_open; 79 static d_mmap_single_t privcmd_mmap_single; 80 81 static struct cdevsw privcmd_devsw = { 82 .d_version = D_VERSION, 83 .d_ioctl = privcmd_ioctl, 84 .d_mmap_single = privcmd_mmap_single, 85 .d_open = privcmd_open, 86 .d_name = "privcmd", 87 }; 88 89 static int privcmd_pg_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 90 vm_ooffset_t foff, struct ucred *cred, u_short *color); 91 static void privcmd_pg_dtor(void *handle); 92 static int privcmd_pg_fault(vm_object_t object, vm_ooffset_t offset, 93 int prot, vm_page_t *mres); 94 95 static struct cdev_pager_ops privcmd_pg_ops = { 96 .cdev_pg_fault = privcmd_pg_fault, 97 .cdev_pg_ctor = privcmd_pg_ctor, 98 .cdev_pg_dtor = privcmd_pg_dtor, 99 }; 100 101 struct per_user_data { 102 domid_t dom; 103 }; 104 105 static device_t privcmd_dev = NULL; 106 107 /*------------------------- Privcmd Pager functions --------------------------*/ 108 static int 109 privcmd_pg_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 110 vm_ooffset_t foff, struct ucred *cred, u_short *color) 111 { 112 113 return (0); 114 } 115 116 static void 117 privcmd_pg_dtor(void *handle) 118 { 119 struct xen_remove_from_physmap rm = { .domid = DOMID_SELF }; 120 struct privcmd_map *map = handle; 121 int error __diagused; 122 vm_size_t i; 123 124 /* 125 * Remove the mappings from the used pages. This will remove the 126 * underlying p2m bindings in Xen second stage translation. 127 */ 128 if (map->mapped == true) { 129 cdev_mgtdev_pager_free_pages(map->mem); 130 for (i = 0; i < map->size; i++) { 131 rm.gpfn = atop(map->phys_base_addr) + i; 132 HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &rm); 133 } 134 free(map->err, M_PRIVCMD); 135 } 136 137 error = xenmem_free(privcmd_dev, map->pseudo_phys_res_id, 138 map->pseudo_phys_res); 139 KASSERT(error == 0, ("Unable to release memory resource: %d", error)); 140 141 free(map, M_PRIVCMD); 142 } 143 144 static int 145 privcmd_pg_fault(vm_object_t object, vm_ooffset_t offset, 146 int prot, vm_page_t *mres) 147 { 148 struct privcmd_map *map = object->handle; 149 vm_pindex_t pidx; 150 vm_page_t page; 151 152 if (map->mapped != true) 153 return (VM_PAGER_FAIL); 154 155 pidx = OFF_TO_IDX(offset); 156 if (pidx >= map->size || BIT_ISSET(map->size, pidx, map->err)) 157 return (VM_PAGER_FAIL); 158 159 page = PHYS_TO_VM_PAGE(map->phys_base_addr + offset); 160 if (page == NULL) 161 return (VM_PAGER_FAIL); 162 163 KASSERT((page->flags & PG_FICTITIOUS) != 0, 164 ("not fictitious %p", page)); 165 KASSERT(vm_page_wired(page), ("page %p not wired", page)); 166 KASSERT(!vm_page_busied(page), ("page %p is busy", page)); 167 168 vm_page_busy_acquire(page, 0); 169 vm_page_valid(page); 170 171 if (*mres != NULL) 172 vm_page_replace(page, object, pidx, *mres); 173 else 174 vm_page_insert(page, object, pidx); 175 *mres = page; 176 return (VM_PAGER_OK); 177 } 178 179 /*----------------------- Privcmd char device methods ------------------------*/ 180 static int 181 privcmd_mmap_single(struct cdev *cdev, vm_ooffset_t *offset, vm_size_t size, 182 vm_object_t *object, int nprot) 183 { 184 struct privcmd_map *map; 185 186 map = malloc(sizeof(*map), M_PRIVCMD, M_WAITOK | M_ZERO); 187 188 map->size = OFF_TO_IDX(size); 189 map->pseudo_phys_res_id = 0; 190 191 map->pseudo_phys_res = xenmem_alloc(privcmd_dev, 192 &map->pseudo_phys_res_id, size); 193 if (map->pseudo_phys_res == NULL) { 194 free(map, M_PRIVCMD); 195 return (ENOMEM); 196 } 197 198 map->phys_base_addr = rman_get_start(map->pseudo_phys_res); 199 map->mem = cdev_pager_allocate(map, OBJT_MGTDEVICE, &privcmd_pg_ops, 200 size, nprot, *offset, NULL); 201 if (map->mem == NULL) { 202 xenmem_free(privcmd_dev, map->pseudo_phys_res_id, 203 map->pseudo_phys_res); 204 free(map, M_PRIVCMD); 205 return (ENOMEM); 206 } 207 208 *object = map->mem; 209 210 return (0); 211 } 212 213 static struct privcmd_map * 214 setup_virtual_area(struct thread *td, unsigned long addr, unsigned long num) 215 { 216 vm_map_t map; 217 vm_map_entry_t entry; 218 vm_object_t mem; 219 vm_pindex_t pindex; 220 vm_prot_t prot; 221 boolean_t wired; 222 struct privcmd_map *umap; 223 int error; 224 225 if ((num == 0) || ((addr & PAGE_MASK) != 0)) 226 return NULL; 227 228 map = &td->td_proc->p_vmspace->vm_map; 229 error = vm_map_lookup(&map, addr, VM_PROT_NONE, &entry, &mem, &pindex, 230 &prot, &wired); 231 if (error != KERN_SUCCESS || (entry->start != addr) || 232 (entry->end != addr + (num * PAGE_SIZE))) 233 return NULL; 234 235 vm_map_lookup_done(map, entry); 236 if ((mem->type != OBJT_MGTDEVICE) || 237 (mem->un_pager.devp.ops != &privcmd_pg_ops)) 238 return NULL; 239 240 umap = mem->handle; 241 /* Allocate a bitset to store broken page mappings. */ 242 umap->err = BITSET_ALLOC(num, M_PRIVCMD, M_WAITOK | M_ZERO); 243 244 return umap; 245 } 246 247 static int 248 privcmd_ioctl(struct cdev *dev, unsigned long cmd, caddr_t arg, 249 int mode, struct thread *td) 250 { 251 int error; 252 unsigned int i; 253 void *data; 254 const struct per_user_data *u; 255 256 error = devfs_get_cdevpriv(&data); 257 if (error != 0) 258 return (EINVAL); 259 /* 260 * Constify user-data to prevent unintended changes to the restriction 261 * limits. 262 */ 263 u = data; 264 265 switch (cmd) { 266 case IOCTL_PRIVCMD_HYPERCALL: { 267 struct ioctl_privcmd_hypercall *hcall; 268 269 hcall = (struct ioctl_privcmd_hypercall *)arg; 270 271 /* Forbid hypercalls if restricted. */ 272 if (u->dom != DOMID_INVALID) { 273 error = EPERM; 274 break; 275 } 276 277 #ifdef __amd64__ 278 /* 279 * The hypervisor page table walker will refuse to access 280 * user-space pages if SMAP is enabled, so temporary disable it 281 * while performing the hypercall. 282 */ 283 if (cpu_stdext_feature & CPUID_STDEXT_SMAP) 284 stac(); 285 #endif 286 error = privcmd_hypercall(hcall->op, hcall->arg[0], 287 hcall->arg[1], hcall->arg[2], hcall->arg[3], hcall->arg[4]); 288 #ifdef __amd64__ 289 if (cpu_stdext_feature & CPUID_STDEXT_SMAP) 290 clac(); 291 #endif 292 if (error >= 0) { 293 hcall->retval = error; 294 error = 0; 295 } else { 296 error = xen_translate_error(error); 297 hcall->retval = 0; 298 } 299 break; 300 } 301 case IOCTL_PRIVCMD_MMAPBATCH: { 302 struct ioctl_privcmd_mmapbatch *mmap; 303 struct xen_add_to_physmap_batch add; 304 xen_ulong_t *idxs; 305 xen_pfn_t *gpfns; 306 int *errs; 307 unsigned int index; 308 struct privcmd_map *umap; 309 uint16_t num; 310 311 mmap = (struct ioctl_privcmd_mmapbatch *)arg; 312 313 if (u->dom != DOMID_INVALID && u->dom != mmap->dom) { 314 error = EPERM; 315 break; 316 } 317 318 umap = setup_virtual_area(td, mmap->addr, mmap->num); 319 if (umap == NULL) { 320 error = EINVAL; 321 break; 322 } 323 324 add.domid = DOMID_SELF; 325 add.space = XENMAPSPACE_gmfn_foreign; 326 add.u.foreign_domid = mmap->dom; 327 328 /* 329 * The 'size' field in the xen_add_to_physmap_range only 330 * allows for UINT16_MAX mappings in a single hypercall. 331 */ 332 num = MIN(mmap->num, UINT16_MAX); 333 334 idxs = malloc(sizeof(*idxs) * num, M_PRIVCMD, M_WAITOK); 335 gpfns = malloc(sizeof(*gpfns) * num, M_PRIVCMD, M_WAITOK); 336 errs = malloc(sizeof(*errs) * num, M_PRIVCMD, M_WAITOK); 337 338 set_xen_guest_handle(add.idxs, idxs); 339 set_xen_guest_handle(add.gpfns, gpfns); 340 set_xen_guest_handle(add.errs, errs); 341 342 for (index = 0; index < mmap->num; index += num) { 343 num = MIN(mmap->num - index, UINT16_MAX); 344 add.size = num; 345 346 error = copyin(&mmap->arr[index], idxs, 347 sizeof(idxs[0]) * num); 348 if (error != 0) 349 goto mmap_out; 350 351 for (i = 0; i < num; i++) 352 gpfns[i] = atop(umap->phys_base_addr + 353 (i + index) * PAGE_SIZE); 354 355 bzero(errs, sizeof(*errs) * num); 356 357 error = HYPERVISOR_memory_op( 358 XENMEM_add_to_physmap_batch, &add); 359 if (error != 0) { 360 error = xen_translate_error(error); 361 goto mmap_out; 362 } 363 364 for (i = 0; i < num; i++) { 365 if (errs[i] != 0) { 366 errs[i] = xen_translate_error(errs[i]); 367 368 /* Mark the page as invalid. */ 369 BIT_SET(mmap->num, index + i, 370 umap->err); 371 } 372 } 373 374 error = copyout(errs, &mmap->err[index], 375 sizeof(errs[0]) * num); 376 if (error != 0) 377 goto mmap_out; 378 } 379 380 umap->mapped = true; 381 382 mmap_out: 383 free(idxs, M_PRIVCMD); 384 free(gpfns, M_PRIVCMD); 385 free(errs, M_PRIVCMD); 386 if (!umap->mapped) 387 free(umap->err, M_PRIVCMD); 388 389 break; 390 } 391 case IOCTL_PRIVCMD_MMAP_RESOURCE: { 392 struct ioctl_privcmd_mmapresource *mmap; 393 struct xen_mem_acquire_resource adq; 394 xen_pfn_t *gpfns; 395 struct privcmd_map *umap; 396 397 mmap = (struct ioctl_privcmd_mmapresource *)arg; 398 399 if (u->dom != DOMID_INVALID && u->dom != mmap->dom) { 400 error = EPERM; 401 break; 402 } 403 404 bzero(&adq, sizeof(adq)); 405 406 adq.domid = mmap->dom; 407 adq.type = mmap->type; 408 adq.id = mmap->id; 409 410 /* Shortcut for getting the resource size. */ 411 if (mmap->addr == 0 && mmap->num == 0) { 412 error = HYPERVISOR_memory_op(XENMEM_acquire_resource, 413 &adq); 414 if (error != 0) 415 error = xen_translate_error(error); 416 else 417 mmap->num = adq.nr_frames; 418 break; 419 } 420 421 umap = setup_virtual_area(td, mmap->addr, mmap->num); 422 if (umap == NULL) { 423 error = EINVAL; 424 break; 425 } 426 427 adq.nr_frames = mmap->num; 428 adq.frame = mmap->idx; 429 430 gpfns = malloc(sizeof(*gpfns) * mmap->num, M_PRIVCMD, M_WAITOK); 431 for (i = 0; i < mmap->num; i++) 432 gpfns[i] = atop(umap->phys_base_addr) + i; 433 set_xen_guest_handle(adq.frame_list, gpfns); 434 435 error = HYPERVISOR_memory_op(XENMEM_acquire_resource, &adq); 436 if (error != 0) 437 error = xen_translate_error(error); 438 else 439 umap->mapped = true; 440 441 free(gpfns, M_PRIVCMD); 442 if (!umap->mapped) 443 free(umap->err, M_PRIVCMD); 444 445 break; 446 } 447 case IOCTL_PRIVCMD_DM_OP: { 448 const struct ioctl_privcmd_dmop *dmop; 449 struct privcmd_dmop_buf *bufs; 450 struct xen_dm_op_buf *hbufs; 451 452 dmop = (struct ioctl_privcmd_dmop *)arg; 453 454 if (u->dom != DOMID_INVALID && u->dom != dmop->dom) { 455 error = EPERM; 456 break; 457 } 458 459 if (dmop->num == 0) 460 break; 461 462 if (dmop->num > MAX_DMOP_BUFFERS) { 463 error = E2BIG; 464 break; 465 } 466 467 bufs = malloc(sizeof(*bufs) * dmop->num, M_PRIVCMD, M_WAITOK); 468 469 error = copyin(dmop->ubufs, bufs, sizeof(*bufs) * dmop->num); 470 if (error != 0) { 471 free(bufs, M_PRIVCMD); 472 break; 473 } 474 475 hbufs = malloc(sizeof(*hbufs) * dmop->num, M_PRIVCMD, M_WAITOK); 476 for (i = 0; i < dmop->num; i++) { 477 set_xen_guest_handle(hbufs[i].h, bufs[i].uptr); 478 hbufs[i].size = bufs[i].size; 479 } 480 481 #ifdef __amd64__ 482 if (cpu_stdext_feature & CPUID_STDEXT_SMAP) 483 stac(); 484 #endif 485 error = HYPERVISOR_dm_op(dmop->dom, dmop->num, hbufs); 486 #ifdef __amd64__ 487 if (cpu_stdext_feature & CPUID_STDEXT_SMAP) 488 clac(); 489 #endif 490 if (error != 0) 491 error = xen_translate_error(error); 492 493 free(bufs, M_PRIVCMD); 494 free(hbufs, M_PRIVCMD); 495 496 497 break; 498 } 499 case IOCTL_PRIVCMD_RESTRICT: { 500 struct per_user_data *u; 501 domid_t dom; 502 503 dom = *(domid_t *)arg; 504 505 error = devfs_get_cdevpriv((void **)&u); 506 if (error != 0) 507 break; 508 509 if (u->dom != DOMID_INVALID && u->dom != dom) { 510 error = -EINVAL; 511 break; 512 } 513 u->dom = dom; 514 515 break; 516 } 517 default: 518 error = ENOSYS; 519 break; 520 } 521 522 return (error); 523 } 524 525 static void 526 user_release(void *arg) 527 { 528 529 free(arg, M_PRIVCMD); 530 } 531 532 static int 533 privcmd_open(struct cdev *dev, int flag, int otyp, struct thread *td) 534 { 535 struct per_user_data *u; 536 int error; 537 538 u = malloc(sizeof(*u), M_PRIVCMD, M_WAITOK); 539 u->dom = DOMID_INVALID; 540 541 /* Assign the allocated per_user_data to this open instance. */ 542 error = devfs_set_cdevpriv(u, user_release); 543 if (error != 0) { 544 free(u, M_PRIVCMD); 545 } 546 547 return (error); 548 } 549 550 /*------------------ Private Device Attachment Functions --------------------*/ 551 static void 552 privcmd_identify(driver_t *driver, device_t parent) 553 { 554 555 KASSERT(xen_domain(), 556 ("Trying to attach privcmd device on non Xen domain")); 557 558 if (BUS_ADD_CHILD(parent, 0, "privcmd", 0) == NULL) 559 panic("unable to attach privcmd user-space device"); 560 } 561 562 static int 563 privcmd_probe(device_t dev) 564 { 565 566 privcmd_dev = dev; 567 device_set_desc(dev, "Xen privileged interface user-space device"); 568 return (BUS_PROBE_NOWILDCARD); 569 } 570 571 static int 572 privcmd_attach(device_t dev) 573 { 574 575 make_dev_credf(MAKEDEV_ETERNAL, &privcmd_devsw, 0, NULL, UID_ROOT, 576 GID_WHEEL, 0600, "xen/privcmd"); 577 return (0); 578 } 579 580 /*-------------------- Private Device Attachment Data -----------------------*/ 581 static device_method_t privcmd_methods[] = { 582 DEVMETHOD(device_identify, privcmd_identify), 583 DEVMETHOD(device_probe, privcmd_probe), 584 DEVMETHOD(device_attach, privcmd_attach), 585 586 DEVMETHOD_END 587 }; 588 589 static driver_t privcmd_driver = { 590 "privcmd", 591 privcmd_methods, 592 0, 593 }; 594 595 DRIVER_MODULE(privcmd, xenpv, privcmd_driver, 0, 0); 596 MODULE_DEPEND(privcmd, xenpv, 1, 1, 1); 597