1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2012 NetApp, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 /* 30 * Memory ranges are represented with an RB tree. On insertion, the range 31 * is checked for overlaps. On lookup, the key has the same base and limit 32 * so it can be searched within the range. 33 */ 34 35 #include <sys/cdefs.h> 36 #include <sys/types.h> 37 #include <sys/errno.h> 38 #include <sys/tree.h> 39 #include <machine/vmm.h> 40 #include <machine/vmm_instruction_emul.h> 41 42 #include <assert.h> 43 #include <err.h> 44 #include <pthread.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <vmmapi.h> 48 49 #include "mem.h" 50 51 struct mmio_rb_range { 52 RB_ENTRY(mmio_rb_range) mr_link; /* RB tree links */ 53 struct mem_range mr_param; 54 uint64_t mr_base; 55 uint64_t mr_end; 56 }; 57 58 struct mmio_rb_tree; 59 RB_PROTOTYPE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare); 60 61 static RB_HEAD(mmio_rb_tree, mmio_rb_range) mmio_rb_root, mmio_rb_fallback; 62 63 /* 64 * Per-vCPU cache. Since most accesses from a vCPU will be to 65 * consecutive addresses in a range, it makes sense to cache the 66 * result of a lookup. 67 */ 68 static struct mmio_rb_range **mmio_hint; 69 static int mmio_ncpu; 70 71 static pthread_rwlock_t mmio_rwlock; 72 73 static int 74 mmio_rb_range_compare(struct mmio_rb_range *a, struct mmio_rb_range *b) 75 { 76 if (a->mr_end < b->mr_base) 77 return (-1); 78 else if (a->mr_base > b->mr_end) 79 return (1); 80 return (0); 81 } 82 83 static int 84 mmio_rb_lookup(struct mmio_rb_tree *rbt, uint64_t addr, 85 struct mmio_rb_range **entry) 86 { 87 struct mmio_rb_range find, *res; 88 89 find.mr_base = find.mr_end = addr; 90 91 res = RB_FIND(mmio_rb_tree, rbt, &find); 92 93 if (res != NULL) { 94 *entry = res; 95 return (0); 96 } 97 98 return (ENOENT); 99 } 100 101 static int 102 mmio_rb_add(struct mmio_rb_tree *rbt, struct mmio_rb_range *new) 103 { 104 struct mmio_rb_range *overlap; 105 106 overlap = RB_INSERT(mmio_rb_tree, rbt, new); 107 108 if (overlap != NULL) { 109 #ifdef RB_DEBUG 110 printf("overlap detected: new %lx:%lx, tree %lx:%lx, '%s' " 111 "claims region already claimed for '%s'\n", 112 new->mr_base, new->mr_end, 113 overlap->mr_base, overlap->mr_end, 114 new->mr_param.name, overlap->mr_param.name); 115 #endif 116 117 return (EEXIST); 118 } 119 120 return (0); 121 } 122 123 #if 0 124 static void 125 mmio_rb_dump(struct mmio_rb_tree *rbt) 126 { 127 int perror; 128 struct mmio_rb_range *np; 129 130 pthread_rwlock_rdlock(&mmio_rwlock); 131 RB_FOREACH(np, mmio_rb_tree, rbt) { 132 printf(" %lx:%lx, %s\n", np->mr_base, np->mr_end, 133 np->mr_param.name); 134 } 135 perror = pthread_rwlock_unlock(&mmio_rwlock); 136 assert(perror == 0); 137 } 138 #endif 139 140 RB_GENERATE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare); 141 142 typedef int (mem_cb_t)(struct vcpu *vcpu, uint64_t gpa, struct mem_range *mr, 143 void *arg); 144 145 static int 146 mem_read(struct vcpu *vcpu, uint64_t gpa, uint64_t *rval, int size, void *arg) 147 { 148 int error; 149 struct mem_range *mr = arg; 150 151 error = (*mr->handler)(vcpu, MEM_F_READ, gpa, size, rval, mr->arg1, 152 mr->arg2); 153 return (error); 154 } 155 156 static int 157 mem_write(struct vcpu *vcpu, uint64_t gpa, uint64_t wval, int size, void *arg) 158 { 159 int error; 160 struct mem_range *mr = arg; 161 162 error = (*mr->handler)(vcpu, MEM_F_WRITE, gpa, size, &wval, mr->arg1, 163 mr->arg2); 164 return (error); 165 } 166 167 static int 168 access_memory(struct vcpu *vcpu, uint64_t paddr, mem_cb_t *cb, void *arg) 169 { 170 struct mmio_rb_range *entry; 171 int err, perror, immutable, vcpuid; 172 173 vcpuid = vcpu_id(vcpu); 174 pthread_rwlock_rdlock(&mmio_rwlock); 175 /* 176 * First check the per-vCPU cache 177 */ 178 if (mmio_hint[vcpuid] && 179 paddr >= mmio_hint[vcpuid]->mr_base && 180 paddr <= mmio_hint[vcpuid]->mr_end) { 181 entry = mmio_hint[vcpuid]; 182 } else 183 entry = NULL; 184 185 if (entry == NULL) { 186 if (mmio_rb_lookup(&mmio_rb_root, paddr, &entry) == 0) { 187 /* Update the per-vCPU cache */ 188 mmio_hint[vcpuid] = entry; 189 } else if (mmio_rb_lookup(&mmio_rb_fallback, paddr, &entry)) { 190 perror = pthread_rwlock_unlock(&mmio_rwlock); 191 assert(perror == 0); 192 return (ESRCH); 193 } 194 } 195 196 assert(entry != NULL); 197 198 /* 199 * An 'immutable' memory range is guaranteed to be never removed 200 * so there is no need to hold 'mmio_rwlock' while calling the 201 * handler. 202 * 203 * XXX writes to the PCIR_COMMAND register can cause register_mem() 204 * to be called. If the guest is using PCI extended config space 205 * to modify the PCIR_COMMAND register then register_mem() can 206 * deadlock on 'mmio_rwlock'. However by registering the extended 207 * config space window as 'immutable' the deadlock can be avoided. 208 */ 209 immutable = (entry->mr_param.flags & MEM_F_IMMUTABLE); 210 if (immutable) { 211 perror = pthread_rwlock_unlock(&mmio_rwlock); 212 assert(perror == 0); 213 } 214 215 err = cb(vcpu, paddr, &entry->mr_param, arg); 216 217 if (!immutable) { 218 perror = pthread_rwlock_unlock(&mmio_rwlock); 219 assert(perror == 0); 220 } 221 222 return (err); 223 } 224 225 struct emulate_mem_args { 226 struct vie *vie; 227 struct vm_guest_paging *paging; 228 }; 229 230 static int 231 emulate_mem_cb(struct vcpu *vcpu, uint64_t paddr, struct mem_range *mr, 232 void *arg) 233 { 234 struct emulate_mem_args *ema; 235 236 ema = arg; 237 return (vmm_emulate_instruction(vcpu, paddr, ema->vie, ema->paging, 238 mem_read, mem_write, mr)); 239 } 240 241 int 242 emulate_mem(struct vcpu *vcpu, uint64_t paddr, struct vie *vie, 243 struct vm_guest_paging *paging) 244 { 245 struct emulate_mem_args ema; 246 247 ema.vie = vie; 248 ema.paging = paging; 249 return (access_memory(vcpu, paddr, emulate_mem_cb, &ema)); 250 } 251 252 struct rw_mem_args { 253 uint64_t *val; 254 int size; 255 int operation; 256 }; 257 258 static int 259 rw_mem_cb(struct vcpu *vcpu, uint64_t paddr, struct mem_range *mr, void *arg) 260 { 261 struct rw_mem_args *rma; 262 263 rma = arg; 264 return (mr->handler(vcpu, rma->operation, paddr, rma->size, 265 rma->val, mr->arg1, mr->arg2)); 266 } 267 268 int 269 read_mem(struct vcpu *vcpu, uint64_t gpa, uint64_t *rval, int size) 270 { 271 struct rw_mem_args rma; 272 273 rma.val = rval; 274 rma.size = size; 275 rma.operation = MEM_F_READ; 276 return (access_memory(vcpu, gpa, rw_mem_cb, &rma)); 277 } 278 279 int 280 write_mem(struct vcpu *vcpu, uint64_t gpa, uint64_t wval, int size) 281 { 282 struct rw_mem_args rma; 283 284 rma.val = &wval; 285 rma.size = size; 286 rma.operation = MEM_F_WRITE; 287 return (access_memory(vcpu, gpa, rw_mem_cb, &rma)); 288 } 289 290 static int 291 register_mem_int(struct mmio_rb_tree *rbt, struct mem_range *memp) 292 { 293 struct mmio_rb_range *entry, *mrp; 294 int err, perror; 295 296 err = 0; 297 298 mrp = malloc(sizeof(struct mmio_rb_range)); 299 if (mrp == NULL) { 300 warn("%s: couldn't allocate memory for mrp\n", 301 __func__); 302 err = ENOMEM; 303 } else { 304 mrp->mr_param = *memp; 305 mrp->mr_base = memp->base; 306 mrp->mr_end = memp->base + memp->size - 1; 307 pthread_rwlock_wrlock(&mmio_rwlock); 308 if (mmio_rb_lookup(rbt, memp->base, &entry) != 0) 309 err = mmio_rb_add(rbt, mrp); 310 perror = pthread_rwlock_unlock(&mmio_rwlock); 311 assert(perror == 0); 312 if (err) 313 free(mrp); 314 } 315 316 return (err); 317 } 318 319 int 320 register_mem(struct mem_range *memp) 321 { 322 323 return (register_mem_int(&mmio_rb_root, memp)); 324 } 325 326 int 327 register_mem_fallback(struct mem_range *memp) 328 { 329 330 return (register_mem_int(&mmio_rb_fallback, memp)); 331 } 332 333 int 334 unregister_mem(struct mem_range *memp) 335 { 336 struct mem_range *mr; 337 struct mmio_rb_range *entry = NULL; 338 int err, perror, i; 339 340 pthread_rwlock_wrlock(&mmio_rwlock); 341 err = mmio_rb_lookup(&mmio_rb_root, memp->base, &entry); 342 if (err == 0) { 343 mr = &entry->mr_param; 344 assert(mr->name == memp->name); 345 assert(mr->base == memp->base && mr->size == memp->size); 346 assert((mr->flags & MEM_F_IMMUTABLE) == 0); 347 RB_REMOVE(mmio_rb_tree, &mmio_rb_root, entry); 348 349 /* flush Per-vCPU cache */ 350 for (i = 0; i < mmio_ncpu; i++) { 351 if (mmio_hint[i] == entry) 352 mmio_hint[i] = NULL; 353 } 354 } 355 perror = pthread_rwlock_unlock(&mmio_rwlock); 356 assert(perror == 0); 357 358 if (entry) 359 free(entry); 360 361 return (err); 362 } 363 364 void 365 init_mem(int ncpu) 366 { 367 368 mmio_ncpu = ncpu; 369 mmio_hint = calloc(ncpu, sizeof(*mmio_hint)); 370 RB_INIT(&mmio_rb_root); 371 RB_INIT(&mmio_rb_fallback); 372 pthread_rwlock_init(&mmio_rwlock, NULL); 373 } 374