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/types.h> 36 #include <sys/errno.h> 37 #include <sys/tree.h> 38 #include <machine/vmm.h> 39 #include <machine/vmm_instruction_emul.h> 40 41 #include <assert.h> 42 #include <err.h> 43 #include <pthread.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <vmmapi.h> 47 48 #include "mem.h" 49 50 struct mmio_rb_range { 51 RB_ENTRY(mmio_rb_range) mr_link; /* RB tree links */ 52 struct mem_range mr_param; 53 uint64_t mr_base; 54 uint64_t mr_end; 55 }; 56 57 struct mmio_rb_tree; 58 RB_PROTOTYPE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare); 59 60 static RB_HEAD(mmio_rb_tree, mmio_rb_range) mmio_rb_root, mmio_rb_fallback; 61 62 /* 63 * Per-vCPU cache. Since most accesses from a vCPU will be to 64 * consecutive addresses in a range, it makes sense to cache the 65 * result of a lookup. 66 */ 67 static struct mmio_rb_range **mmio_hint; 68 static int mmio_ncpu; 69 70 static pthread_rwlock_t mmio_rwlock; 71 72 static int 73 mmio_rb_range_compare(struct mmio_rb_range *a, struct mmio_rb_range *b) 74 { 75 if (a->mr_end < b->mr_base) 76 return (-1); 77 else if (a->mr_base > b->mr_end) 78 return (1); 79 return (0); 80 } 81 82 static int 83 mmio_rb_lookup(struct mmio_rb_tree *rbt, uint64_t addr, 84 struct mmio_rb_range **entry) 85 { 86 struct mmio_rb_range find, *res; 87 88 find.mr_base = find.mr_end = addr; 89 90 res = RB_FIND(mmio_rb_tree, rbt, &find); 91 92 if (res != NULL) { 93 *entry = res; 94 return (0); 95 } 96 97 return (ENOENT); 98 } 99 100 static int 101 mmio_rb_add(struct mmio_rb_tree *rbt, struct mmio_rb_range *new) 102 { 103 struct mmio_rb_range *overlap; 104 105 overlap = RB_INSERT(mmio_rb_tree, rbt, new); 106 107 if (overlap != NULL) { 108 #ifdef RB_DEBUG 109 printf("overlap detected: new %lx:%lx, tree %lx:%lx, '%s' " 110 "claims region already claimed for '%s'\n", 111 new->mr_base, new->mr_end, 112 overlap->mr_base, overlap->mr_end, 113 new->mr_param.name, overlap->mr_param.name); 114 #endif 115 116 return (EEXIST); 117 } 118 119 return (0); 120 } 121 122 #if 0 123 static void 124 mmio_rb_dump(struct mmio_rb_tree *rbt) 125 { 126 int perror; 127 struct mmio_rb_range *np; 128 129 pthread_rwlock_rdlock(&mmio_rwlock); 130 RB_FOREACH(np, mmio_rb_tree, rbt) { 131 printf(" %lx:%lx, %s\n", np->mr_base, np->mr_end, 132 np->mr_param.name); 133 } 134 perror = pthread_rwlock_unlock(&mmio_rwlock); 135 assert(perror == 0); 136 } 137 #endif 138 139 RB_GENERATE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare); 140 141 typedef int (mem_cb_t)(struct vcpu *vcpu, uint64_t gpa, struct mem_range *mr, 142 void *arg); 143 144 static int 145 mem_read(struct vcpu *vcpu, uint64_t gpa, uint64_t *rval, int size, void *arg) 146 { 147 int error; 148 struct mem_range *mr = arg; 149 150 error = (*mr->handler)(vcpu, MEM_F_READ, gpa, size, rval, mr->arg1, 151 mr->arg2); 152 return (error); 153 } 154 155 static int 156 mem_write(struct vcpu *vcpu, uint64_t gpa, uint64_t wval, int size, void *arg) 157 { 158 int error; 159 struct mem_range *mr = arg; 160 161 error = (*mr->handler)(vcpu, MEM_F_WRITE, gpa, size, &wval, mr->arg1, 162 mr->arg2); 163 return (error); 164 } 165 166 static int 167 access_memory(struct vcpu *vcpu, uint64_t paddr, mem_cb_t *cb, void *arg) 168 { 169 struct mmio_rb_range *entry; 170 int err, perror, immutable, vcpuid; 171 172 vcpuid = vcpu_id(vcpu); 173 pthread_rwlock_rdlock(&mmio_rwlock); 174 /* 175 * First check the per-vCPU cache 176 */ 177 if (mmio_hint[vcpuid] && 178 paddr >= mmio_hint[vcpuid]->mr_base && 179 paddr <= mmio_hint[vcpuid]->mr_end) { 180 entry = mmio_hint[vcpuid]; 181 } else 182 entry = NULL; 183 184 if (entry == NULL) { 185 if (mmio_rb_lookup(&mmio_rb_root, paddr, &entry) == 0) { 186 /* Update the per-vCPU cache */ 187 mmio_hint[vcpuid] = entry; 188 } else if (mmio_rb_lookup(&mmio_rb_fallback, paddr, &entry)) { 189 perror = pthread_rwlock_unlock(&mmio_rwlock); 190 assert(perror == 0); 191 return (ESRCH); 192 } 193 } 194 195 assert(entry != NULL); 196 197 /* 198 * An 'immutable' memory range is guaranteed to be never removed 199 * so there is no need to hold 'mmio_rwlock' while calling the 200 * handler. 201 * 202 * XXX writes to the PCIR_COMMAND register can cause register_mem() 203 * to be called. If the guest is using PCI extended config space 204 * to modify the PCIR_COMMAND register then register_mem() can 205 * deadlock on 'mmio_rwlock'. However by registering the extended 206 * config space window as 'immutable' the deadlock can be avoided. 207 */ 208 immutable = (entry->mr_param.flags & MEM_F_IMMUTABLE); 209 if (immutable) { 210 perror = pthread_rwlock_unlock(&mmio_rwlock); 211 assert(perror == 0); 212 } 213 214 err = cb(vcpu, paddr, &entry->mr_param, arg); 215 216 if (!immutable) { 217 perror = pthread_rwlock_unlock(&mmio_rwlock); 218 assert(perror == 0); 219 } 220 221 return (err); 222 } 223 224 struct emulate_mem_args { 225 struct vie *vie; 226 struct vm_guest_paging *paging; 227 }; 228 229 static int 230 emulate_mem_cb(struct vcpu *vcpu, uint64_t paddr, struct mem_range *mr, 231 void *arg) 232 { 233 struct emulate_mem_args *ema; 234 235 ema = arg; 236 return (vmm_emulate_instruction(vcpu, paddr, ema->vie, ema->paging, 237 mem_read, mem_write, mr)); 238 } 239 240 int 241 emulate_mem(struct vcpu *vcpu, uint64_t paddr, struct vie *vie, 242 struct vm_guest_paging *paging) 243 { 244 struct emulate_mem_args ema; 245 246 ema.vie = vie; 247 ema.paging = paging; 248 return (access_memory(vcpu, paddr, emulate_mem_cb, &ema)); 249 } 250 251 struct rw_mem_args { 252 uint64_t *val; 253 int size; 254 int operation; 255 }; 256 257 static int 258 rw_mem_cb(struct vcpu *vcpu, uint64_t paddr, struct mem_range *mr, void *arg) 259 { 260 struct rw_mem_args *rma; 261 262 rma = arg; 263 return (mr->handler(vcpu, rma->operation, paddr, rma->size, 264 rma->val, mr->arg1, mr->arg2)); 265 } 266 267 int 268 read_mem(struct vcpu *vcpu, uint64_t gpa, uint64_t *rval, int size) 269 { 270 struct rw_mem_args rma; 271 272 rma.val = rval; 273 rma.size = size; 274 rma.operation = MEM_F_READ; 275 return (access_memory(vcpu, gpa, rw_mem_cb, &rma)); 276 } 277 278 int 279 write_mem(struct vcpu *vcpu, uint64_t gpa, uint64_t wval, int size) 280 { 281 struct rw_mem_args rma; 282 283 rma.val = &wval; 284 rma.size = size; 285 rma.operation = MEM_F_WRITE; 286 return (access_memory(vcpu, gpa, rw_mem_cb, &rma)); 287 } 288 289 static int 290 register_mem_int(struct mmio_rb_tree *rbt, struct mem_range *memp) 291 { 292 struct mmio_rb_range *entry, *mrp; 293 int err, perror; 294 295 err = 0; 296 297 mrp = malloc(sizeof(struct mmio_rb_range)); 298 if (mrp == NULL) { 299 warn("%s: couldn't allocate memory for mrp\n", 300 __func__); 301 err = ENOMEM; 302 } else { 303 mrp->mr_param = *memp; 304 mrp->mr_base = memp->base; 305 mrp->mr_end = memp->base + memp->size - 1; 306 pthread_rwlock_wrlock(&mmio_rwlock); 307 if (mmio_rb_lookup(rbt, memp->base, &entry) != 0) 308 err = mmio_rb_add(rbt, mrp); 309 perror = pthread_rwlock_unlock(&mmio_rwlock); 310 assert(perror == 0); 311 if (err) 312 free(mrp); 313 } 314 315 return (err); 316 } 317 318 int 319 register_mem(struct mem_range *memp) 320 { 321 322 return (register_mem_int(&mmio_rb_root, memp)); 323 } 324 325 int 326 register_mem_fallback(struct mem_range *memp) 327 { 328 329 return (register_mem_int(&mmio_rb_fallback, memp)); 330 } 331 332 int 333 unregister_mem(struct mem_range *memp) 334 { 335 struct mem_range *mr; 336 struct mmio_rb_range *entry = NULL; 337 int err, perror, i; 338 339 pthread_rwlock_wrlock(&mmio_rwlock); 340 err = mmio_rb_lookup(&mmio_rb_root, memp->base, &entry); 341 if (err == 0) { 342 mr = &entry->mr_param; 343 assert(mr->name == memp->name); 344 assert(mr->base == memp->base && mr->size == memp->size); 345 assert((mr->flags & MEM_F_IMMUTABLE) == 0); 346 RB_REMOVE(mmio_rb_tree, &mmio_rb_root, entry); 347 348 /* flush Per-vCPU cache */ 349 for (i = 0; i < mmio_ncpu; i++) { 350 if (mmio_hint[i] == entry) 351 mmio_hint[i] = NULL; 352 } 353 } 354 perror = pthread_rwlock_unlock(&mmio_rwlock); 355 assert(perror == 0); 356 357 if (entry) 358 free(entry); 359 360 return (err); 361 } 362 363 void 364 init_mem(int ncpu) 365 { 366 367 mmio_ncpu = ncpu; 368 mmio_hint = calloc(ncpu, sizeof(*mmio_hint)); 369 RB_INIT(&mmio_rb_root); 370 RB_INIT(&mmio_rb_fallback); 371 pthread_rwlock_init(&mmio_rwlock, NULL); 372 } 373