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/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/uio.h> 33 #include <sys/bus.h> 34 #include <sys/malloc.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/mutex.h> 38 #include <sys/rwlock.h> 39 #include <sys/selinfo.h> 40 #include <sys/poll.h> 41 #include <sys/conf.h> 42 #include <sys/fcntl.h> 43 #include <sys/ioccom.h> 44 #include <sys/rman.h> 45 #include <sys/tree.h> 46 #include <sys/module.h> 47 #include <sys/proc.h> 48 #include <sys/bitset.h> 49 50 #include <vm/vm.h> 51 #include <vm/vm_param.h> 52 #include <vm/vm_extern.h> 53 #include <vm/vm_kern.h> 54 #include <vm/vm_page.h> 55 #include <vm/vm_map.h> 56 #include <vm/vm_object.h> 57 #include <vm/vm_pager.h> 58 59 #include <machine/md_var.h> 60 61 #include <xen/xen-os.h> 62 #include <xen/hypervisor.h> 63 #include <xen/privcmd.h> 64 #include <xen/error.h> 65 66 MALLOC_DEFINE(M_PRIVCMD, "privcmd_dev", "Xen privcmd user-space device"); 67 68 struct privcmd_map { 69 vm_object_t mem; 70 vm_size_t size; 71 struct resource *pseudo_phys_res; 72 int pseudo_phys_res_id; 73 vm_paddr_t phys_base_addr; 74 boolean_t mapped; 75 BITSET_DEFINE_VAR() *err; 76 }; 77 78 static d_ioctl_t privcmd_ioctl; 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_name = "privcmd", 86 }; 87 88 static int privcmd_pg_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 89 vm_ooffset_t foff, struct ucred *cred, u_short *color); 90 static void privcmd_pg_dtor(void *handle); 91 static int privcmd_pg_fault(vm_object_t object, vm_ooffset_t offset, 92 int prot, vm_page_t *mres); 93 94 static struct cdev_pager_ops privcmd_pg_ops = { 95 .cdev_pg_fault = privcmd_pg_fault, 96 .cdev_pg_ctor = privcmd_pg_ctor, 97 .cdev_pg_dtor = privcmd_pg_dtor, 98 }; 99 100 static device_t privcmd_dev = NULL; 101 102 /*------------------------- Privcmd Pager functions --------------------------*/ 103 static int 104 privcmd_pg_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 105 vm_ooffset_t foff, struct ucred *cred, u_short *color) 106 { 107 108 return (0); 109 } 110 111 static void 112 privcmd_pg_dtor(void *handle) 113 { 114 struct xen_remove_from_physmap rm = { .domid = DOMID_SELF }; 115 struct privcmd_map *map = handle; 116 int error; 117 vm_size_t i; 118 vm_page_t m; 119 120 /* 121 * Remove the mappings from the used pages. This will remove the 122 * underlying p2m bindings in Xen second stage translation. 123 */ 124 if (map->mapped == true) { 125 VM_OBJECT_WLOCK(map->mem); 126 retry: 127 for (i = 0; i < map->size; i++) { 128 m = vm_page_lookup(map->mem, i); 129 if (m == NULL) 130 continue; 131 if (vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL) == 0) 132 goto retry; 133 cdev_pager_free_page(map->mem, m); 134 } 135 VM_OBJECT_WUNLOCK(map->mem); 136 137 for (i = 0; i < map->size; i++) { 138 rm.gpfn = atop(map->phys_base_addr) + i; 139 HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &rm); 140 } 141 free(map->err, M_PRIVCMD); 142 } 143 144 error = xenmem_free(privcmd_dev, map->pseudo_phys_res_id, 145 map->pseudo_phys_res); 146 KASSERT(error == 0, ("Unable to release memory resource: %d", error)); 147 148 free(map, M_PRIVCMD); 149 } 150 151 static int 152 privcmd_pg_fault(vm_object_t object, vm_ooffset_t offset, 153 int prot, vm_page_t *mres) 154 { 155 struct privcmd_map *map = object->handle; 156 vm_pindex_t pidx; 157 vm_page_t page; 158 159 if (map->mapped != true) 160 return (VM_PAGER_FAIL); 161 162 pidx = OFF_TO_IDX(offset); 163 if (pidx >= map->size || BIT_ISSET(map->size, pidx, map->err)) 164 return (VM_PAGER_FAIL); 165 166 page = PHYS_TO_VM_PAGE(map->phys_base_addr + offset); 167 if (page == NULL) 168 return (VM_PAGER_FAIL); 169 170 KASSERT((page->flags & PG_FICTITIOUS) != 0, 171 ("not fictitious %p", page)); 172 KASSERT(vm_page_wired(page), ("page %p not wired", page)); 173 KASSERT(!vm_page_busied(page), ("page %p is busy", page)); 174 175 vm_page_busy_acquire(page, 0); 176 vm_page_valid(page); 177 178 if (*mres != NULL) 179 vm_page_replace(page, object, pidx, *mres); 180 else 181 vm_page_insert(page, object, pidx); 182 *mres = page; 183 return (VM_PAGER_OK); 184 } 185 186 /*----------------------- Privcmd char device methods ------------------------*/ 187 static int 188 privcmd_mmap_single(struct cdev *cdev, vm_ooffset_t *offset, vm_size_t size, 189 vm_object_t *object, int nprot) 190 { 191 struct privcmd_map *map; 192 193 map = malloc(sizeof(*map), M_PRIVCMD, M_WAITOK | M_ZERO); 194 195 map->size = OFF_TO_IDX(size); 196 map->pseudo_phys_res_id = 0; 197 198 map->pseudo_phys_res = xenmem_alloc(privcmd_dev, 199 &map->pseudo_phys_res_id, size); 200 if (map->pseudo_phys_res == NULL) { 201 free(map, M_PRIVCMD); 202 return (ENOMEM); 203 } 204 205 map->phys_base_addr = rman_get_start(map->pseudo_phys_res); 206 map->mem = cdev_pager_allocate(map, OBJT_MGTDEVICE, &privcmd_pg_ops, 207 size, nprot, *offset, NULL); 208 if (map->mem == NULL) { 209 xenmem_free(privcmd_dev, map->pseudo_phys_res_id, 210 map->pseudo_phys_res); 211 free(map, M_PRIVCMD); 212 return (ENOMEM); 213 } 214 215 *object = map->mem; 216 217 return (0); 218 } 219 220 static int 221 privcmd_ioctl(struct cdev *dev, unsigned long cmd, caddr_t arg, 222 int mode, struct thread *td) 223 { 224 int error, i; 225 226 switch (cmd) { 227 case IOCTL_PRIVCMD_HYPERCALL: { 228 struct ioctl_privcmd_hypercall *hcall; 229 230 hcall = (struct ioctl_privcmd_hypercall *)arg; 231 #ifdef __amd64__ 232 /* 233 * The hypervisor page table walker will refuse to access 234 * user-space pages if SMAP is enabled, so temporary disable it 235 * while performing the hypercall. 236 */ 237 if (cpu_stdext_feature & CPUID_STDEXT_SMAP) 238 stac(); 239 #endif 240 error = privcmd_hypercall(hcall->op, hcall->arg[0], 241 hcall->arg[1], hcall->arg[2], hcall->arg[3], hcall->arg[4]); 242 #ifdef __amd64__ 243 if (cpu_stdext_feature & CPUID_STDEXT_SMAP) 244 clac(); 245 #endif 246 if (error >= 0) { 247 hcall->retval = error; 248 error = 0; 249 } else { 250 error = xen_translate_error(error); 251 hcall->retval = 0; 252 } 253 break; 254 } 255 case IOCTL_PRIVCMD_MMAPBATCH: { 256 struct ioctl_privcmd_mmapbatch *mmap; 257 vm_map_t map; 258 vm_map_entry_t entry; 259 vm_object_t mem; 260 vm_pindex_t pindex; 261 vm_prot_t prot; 262 boolean_t wired; 263 struct xen_add_to_physmap_range add; 264 xen_ulong_t *idxs; 265 xen_pfn_t *gpfns; 266 int *errs, index; 267 struct privcmd_map *umap; 268 uint16_t num; 269 270 mmap = (struct ioctl_privcmd_mmapbatch *)arg; 271 272 if ((mmap->num == 0) || 273 ((mmap->addr & PAGE_MASK) != 0)) { 274 error = EINVAL; 275 break; 276 } 277 278 map = &td->td_proc->p_vmspace->vm_map; 279 error = vm_map_lookup(&map, mmap->addr, VM_PROT_NONE, &entry, 280 &mem, &pindex, &prot, &wired); 281 if (error != KERN_SUCCESS) { 282 error = EINVAL; 283 break; 284 } 285 if ((entry->start != mmap->addr) || 286 (entry->end != mmap->addr + (mmap->num * PAGE_SIZE))) { 287 vm_map_lookup_done(map, entry); 288 error = EINVAL; 289 break; 290 } 291 vm_map_lookup_done(map, entry); 292 if ((mem->type != OBJT_MGTDEVICE) || 293 (mem->un_pager.devp.ops != &privcmd_pg_ops)) { 294 error = EINVAL; 295 break; 296 } 297 umap = mem->handle; 298 299 add.domid = DOMID_SELF; 300 add.space = XENMAPSPACE_gmfn_foreign; 301 add.foreign_domid = mmap->dom; 302 303 /* 304 * The 'size' field in the xen_add_to_physmap_range only 305 * allows for UINT16_MAX mappings in a single hypercall. 306 */ 307 num = MIN(mmap->num, UINT16_MAX); 308 309 idxs = malloc(sizeof(*idxs) * num, M_PRIVCMD, M_WAITOK); 310 gpfns = malloc(sizeof(*gpfns) * num, M_PRIVCMD, M_WAITOK); 311 errs = malloc(sizeof(*errs) * num, M_PRIVCMD, M_WAITOK); 312 313 set_xen_guest_handle(add.idxs, idxs); 314 set_xen_guest_handle(add.gpfns, gpfns); 315 set_xen_guest_handle(add.errs, errs); 316 317 /* Allocate a bitset to store broken page mappings. */ 318 umap->err = BITSET_ALLOC(mmap->num, M_PRIVCMD, 319 M_WAITOK | M_ZERO); 320 321 for (index = 0; index < mmap->num; index += num) { 322 num = MIN(mmap->num - index, UINT16_MAX); 323 add.size = num; 324 325 error = copyin(&mmap->arr[index], idxs, 326 sizeof(idxs[0]) * num); 327 if (error != 0) 328 goto mmap_out; 329 330 for (i = 0; i < num; i++) 331 gpfns[i] = atop(umap->phys_base_addr + 332 (i + index) * PAGE_SIZE); 333 334 bzero(errs, sizeof(*errs) * num); 335 336 error = HYPERVISOR_memory_op( 337 XENMEM_add_to_physmap_range, &add); 338 if (error != 0) { 339 error = xen_translate_error(error); 340 goto mmap_out; 341 } 342 343 for (i = 0; i < num; i++) { 344 if (errs[i] != 0) { 345 errs[i] = xen_translate_error(errs[i]); 346 347 /* Mark the page as invalid. */ 348 BIT_SET(mmap->num, index + i, 349 umap->err); 350 } 351 } 352 353 error = copyout(errs, &mmap->err[index], 354 sizeof(errs[0]) * num); 355 if (error != 0) 356 goto mmap_out; 357 } 358 359 umap->mapped = true; 360 361 mmap_out: 362 free(idxs, M_PRIVCMD); 363 free(gpfns, M_PRIVCMD); 364 free(errs, M_PRIVCMD); 365 if (!umap->mapped) 366 free(umap->err, M_PRIVCMD); 367 368 break; 369 } 370 371 default: 372 error = ENOSYS; 373 break; 374 } 375 376 return (error); 377 } 378 379 /*------------------ Private Device Attachment Functions --------------------*/ 380 static void 381 privcmd_identify(driver_t *driver, device_t parent) 382 { 383 384 KASSERT(xen_domain(), 385 ("Trying to attach privcmd device on non Xen domain")); 386 387 if (BUS_ADD_CHILD(parent, 0, "privcmd", 0) == NULL) 388 panic("unable to attach privcmd user-space device"); 389 } 390 391 static int 392 privcmd_probe(device_t dev) 393 { 394 395 privcmd_dev = dev; 396 device_set_desc(dev, "Xen privileged interface user-space device"); 397 return (BUS_PROBE_NOWILDCARD); 398 } 399 400 static int 401 privcmd_attach(device_t dev) 402 { 403 404 make_dev_credf(MAKEDEV_ETERNAL, &privcmd_devsw, 0, NULL, UID_ROOT, 405 GID_WHEEL, 0600, "xen/privcmd"); 406 return (0); 407 } 408 409 /*-------------------- Private Device Attachment Data -----------------------*/ 410 static device_method_t privcmd_methods[] = { 411 DEVMETHOD(device_identify, privcmd_identify), 412 DEVMETHOD(device_probe, privcmd_probe), 413 DEVMETHOD(device_attach, privcmd_attach), 414 415 DEVMETHOD_END 416 }; 417 418 static driver_t privcmd_driver = { 419 "privcmd", 420 privcmd_methods, 421 0, 422 }; 423 424 devclass_t privcmd_devclass; 425 426 DRIVER_MODULE(privcmd, xenpv, privcmd_driver, privcmd_devclass, 0, 0); 427 MODULE_DEPEND(privcmd, xenpv, 1, 1, 1); 428