1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 * $FreeBSD$ 29 */ 30 31 /* 32 * Memory ranges are represented with an RB tree. On insertion, the range 33 * is checked for overlaps. On lookup, the key has the same base and limit 34 * so it can be searched within the range. 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/types.h> 41 #include <sys/errno.h> 42 #include <sys/tree.h> 43 #include <machine/vmm.h> 44 #include <machine/vmm_instruction_emul.h> 45 46 #include <assert.h> 47 #include <err.h> 48 #include <pthread.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 52 #include "mem.h" 53 54 struct mmio_rb_range { 55 RB_ENTRY(mmio_rb_range) mr_link; /* RB tree links */ 56 struct mem_range mr_param; 57 uint64_t mr_base; 58 uint64_t mr_end; 59 }; 60 61 struct mmio_rb_tree; 62 RB_PROTOTYPE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare); 63 64 RB_HEAD(mmio_rb_tree, mmio_rb_range) mmio_rb_root, mmio_rb_fallback; 65 66 /* 67 * Per-vCPU cache. Since most accesses from a vCPU will be to 68 * consecutive addresses in a range, it makes sense to cache the 69 * result of a lookup. 70 */ 71 static struct mmio_rb_range *mmio_hint[VM_MAXCPU]; 72 73 static pthread_rwlock_t mmio_rwlock; 74 75 static int 76 mmio_rb_range_compare(struct mmio_rb_range *a, struct mmio_rb_range *b) 77 { 78 if (a->mr_end < b->mr_base) 79 return (-1); 80 else if (a->mr_base > b->mr_end) 81 return (1); 82 return (0); 83 } 84 85 static int 86 mmio_rb_lookup(struct mmio_rb_tree *rbt, uint64_t addr, 87 struct mmio_rb_range **entry) 88 { 89 struct mmio_rb_range find, *res; 90 91 find.mr_base = find.mr_end = addr; 92 93 res = RB_FIND(mmio_rb_tree, rbt, &find); 94 95 if (res != NULL) { 96 *entry = res; 97 return (0); 98 } 99 100 return (ENOENT); 101 } 102 103 static int 104 mmio_rb_add(struct mmio_rb_tree *rbt, struct mmio_rb_range *new) 105 { 106 struct mmio_rb_range *overlap; 107 108 overlap = RB_INSERT(mmio_rb_tree, rbt, new); 109 110 if (overlap != NULL) { 111 #ifdef RB_DEBUG 112 printf("overlap detected: new %lx:%lx, tree %lx:%lx, '%s' " 113 "claims region already claimed for '%s'\n", 114 new->mr_base, new->mr_end, 115 overlap->mr_base, overlap->mr_end, 116 new->mr_param.name, overlap->mr_param.name); 117 #endif 118 119 return (EEXIST); 120 } 121 122 return (0); 123 } 124 125 #if 0 126 static void 127 mmio_rb_dump(struct mmio_rb_tree *rbt) 128 { 129 int perror; 130 struct mmio_rb_range *np; 131 132 pthread_rwlock_rdlock(&mmio_rwlock); 133 RB_FOREACH(np, mmio_rb_tree, rbt) { 134 printf(" %lx:%lx, %s\n", np->mr_base, np->mr_end, 135 np->mr_param.name); 136 } 137 perror = pthread_rwlock_unlock(&mmio_rwlock); 138 assert(perror == 0); 139 } 140 #endif 141 142 RB_GENERATE(mmio_rb_tree, mmio_rb_range, mr_link, mmio_rb_range_compare); 143 144 typedef int (mem_cb_t)(struct vmctx *ctx, int vcpu, uint64_t gpa, 145 struct mem_range *mr, void *arg); 146 147 static int 148 mem_read(void *ctx, int vcpu, uint64_t gpa, uint64_t *rval, int size, void *arg) 149 { 150 int error; 151 struct mem_range *mr = arg; 152 153 error = (*mr->handler)(ctx, vcpu, MEM_F_READ, gpa, size, 154 rval, mr->arg1, mr->arg2); 155 return (error); 156 } 157 158 static int 159 mem_write(void *ctx, int vcpu, uint64_t gpa, uint64_t wval, int size, void *arg) 160 { 161 int error; 162 struct mem_range *mr = arg; 163 164 error = (*mr->handler)(ctx, vcpu, MEM_F_WRITE, gpa, size, 165 &wval, mr->arg1, mr->arg2); 166 return (error); 167 } 168 169 static int 170 access_memory(struct vmctx *ctx, int vcpu, uint64_t paddr, mem_cb_t *cb, 171 void *arg) 172 { 173 struct mmio_rb_range *entry; 174 int err, perror, immutable; 175 176 pthread_rwlock_rdlock(&mmio_rwlock); 177 /* 178 * First check the per-vCPU cache 179 */ 180 if (mmio_hint[vcpu] && 181 paddr >= mmio_hint[vcpu]->mr_base && 182 paddr <= mmio_hint[vcpu]->mr_end) { 183 entry = mmio_hint[vcpu]; 184 } else 185 entry = NULL; 186 187 if (entry == NULL) { 188 if (mmio_rb_lookup(&mmio_rb_root, paddr, &entry) == 0) { 189 /* Update the per-vCPU cache */ 190 mmio_hint[vcpu] = entry; 191 } else if (mmio_rb_lookup(&mmio_rb_fallback, paddr, &entry)) { 192 perror = pthread_rwlock_unlock(&mmio_rwlock); 193 assert(perror == 0); 194 return (ESRCH); 195 } 196 } 197 198 assert(entry != NULL); 199 200 /* 201 * An 'immutable' memory range is guaranteed to be never removed 202 * so there is no need to hold 'mmio_rwlock' while calling the 203 * handler. 204 * 205 * XXX writes to the PCIR_COMMAND register can cause register_mem() 206 * to be called. If the guest is using PCI extended config space 207 * to modify the PCIR_COMMAND register then register_mem() can 208 * deadlock on 'mmio_rwlock'. However by registering the extended 209 * config space window as 'immutable' the deadlock can be avoided. 210 */ 211 immutable = (entry->mr_param.flags & MEM_F_IMMUTABLE); 212 if (immutable) { 213 perror = pthread_rwlock_unlock(&mmio_rwlock); 214 assert(perror == 0); 215 } 216 217 err = cb(ctx, vcpu, paddr, &entry->mr_param, arg); 218 219 if (!immutable) { 220 perror = pthread_rwlock_unlock(&mmio_rwlock); 221 assert(perror == 0); 222 } 223 224 225 return (err); 226 } 227 228 struct emulate_mem_args { 229 struct vie *vie; 230 struct vm_guest_paging *paging; 231 }; 232 233 static int 234 emulate_mem_cb(struct vmctx *ctx, int vcpu, uint64_t paddr, struct mem_range *mr, 235 void *arg) 236 { 237 struct emulate_mem_args *ema; 238 239 ema = arg; 240 return (vmm_emulate_instruction(ctx, vcpu, paddr, ema->vie, ema->paging, 241 mem_read, mem_write, mr)); 242 } 243 244 int 245 emulate_mem(struct vmctx *ctx, int vcpu, uint64_t paddr, struct vie *vie, 246 struct vm_guest_paging *paging) 247 248 { 249 struct emulate_mem_args ema; 250 251 ema.vie = vie; 252 ema.paging = paging; 253 return (access_memory(ctx, vcpu, paddr, emulate_mem_cb, &ema)); 254 } 255 256 struct rw_mem_args { 257 uint64_t *val; 258 int size; 259 int operation; 260 }; 261 262 static int 263 rw_mem_cb(struct vmctx *ctx, int vcpu, uint64_t paddr, struct mem_range *mr, 264 void *arg) 265 { 266 struct rw_mem_args *rma; 267 268 rma = arg; 269 return (mr->handler(ctx, vcpu, rma->operation, paddr, rma->size, 270 rma->val, mr->arg1, mr->arg2)); 271 } 272 273 int 274 read_mem(struct vmctx *ctx, int vcpu, uint64_t gpa, uint64_t *rval, int size) 275 { 276 struct rw_mem_args rma; 277 278 rma.val = rval; 279 rma.size = size; 280 rma.operation = MEM_F_READ; 281 return (access_memory(ctx, vcpu, gpa, rw_mem_cb, &rma)); 282 } 283 284 int 285 write_mem(struct vmctx *ctx, int vcpu, uint64_t gpa, uint64_t wval, int size) 286 { 287 struct rw_mem_args rma; 288 289 rma.val = &wval; 290 rma.size = size; 291 rma.operation = MEM_F_WRITE; 292 return (access_memory(ctx, vcpu, gpa, rw_mem_cb, &rma)); 293 } 294 295 static int 296 register_mem_int(struct mmio_rb_tree *rbt, struct mem_range *memp) 297 { 298 struct mmio_rb_range *entry, *mrp; 299 int err, perror; 300 301 err = 0; 302 303 mrp = malloc(sizeof(struct mmio_rb_range)); 304 if (mrp == NULL) { 305 warn("%s: couldn't allocate memory for mrp\n", 306 __func__); 307 err = ENOMEM; 308 } else { 309 mrp->mr_param = *memp; 310 mrp->mr_base = memp->base; 311 mrp->mr_end = memp->base + memp->size - 1; 312 pthread_rwlock_wrlock(&mmio_rwlock); 313 if (mmio_rb_lookup(rbt, memp->base, &entry) != 0) 314 err = mmio_rb_add(rbt, mrp); 315 perror = pthread_rwlock_unlock(&mmio_rwlock); 316 assert(perror == 0); 317 if (err) 318 free(mrp); 319 } 320 321 return (err); 322 } 323 324 int 325 register_mem(struct mem_range *memp) 326 { 327 328 return (register_mem_int(&mmio_rb_root, memp)); 329 } 330 331 int 332 register_mem_fallback(struct mem_range *memp) 333 { 334 335 return (register_mem_int(&mmio_rb_fallback, memp)); 336 } 337 338 int 339 unregister_mem(struct mem_range *memp) 340 { 341 struct mem_range *mr; 342 struct mmio_rb_range *entry = NULL; 343 int err, perror, i; 344 345 pthread_rwlock_wrlock(&mmio_rwlock); 346 err = mmio_rb_lookup(&mmio_rb_root, memp->base, &entry); 347 if (err == 0) { 348 mr = &entry->mr_param; 349 assert(mr->name == memp->name); 350 assert(mr->base == memp->base && mr->size == memp->size); 351 assert((mr->flags & MEM_F_IMMUTABLE) == 0); 352 RB_REMOVE(mmio_rb_tree, &mmio_rb_root, entry); 353 354 /* flush Per-vCPU cache */ 355 for (i=0; i < VM_MAXCPU; i++) { 356 if (mmio_hint[i] == entry) 357 mmio_hint[i] = NULL; 358 } 359 } 360 perror = pthread_rwlock_unlock(&mmio_rwlock); 361 assert(perror == 0); 362 363 if (entry) 364 free(entry); 365 366 return (err); 367 } 368 369 void 370 init_mem(void) 371 { 372 373 RB_INIT(&mmio_rb_root); 374 RB_INIT(&mmio_rb_fallback); 375 pthread_rwlock_init(&mmio_rwlock, NULL); 376 } 377