1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2015 Neel Natu <neel@freebsd.org> 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 THE AUTHOR ``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 THE AUTHOR 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 #include <sys/param.h> 30 #include <sys/types.h> 31 #include <sys/mman.h> 32 #include <sys/stat.h> 33 34 #include <machine/vmm.h> 35 36 #include <err.h> 37 #include <errno.h> 38 #include <fcntl.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <unistd.h> 43 #include <stdbool.h> 44 45 #include <vmmapi.h> 46 47 #include "bhyverun.h" 48 #include "bootrom.h" 49 #include "debug.h" 50 #include "mem.h" 51 52 #define BOOTROM_SIZE (16 * 1024 * 1024) /* 16 MB */ 53 54 /* 55 * ROM region is 16 MB at the top of 4GB ("low") memory. 56 * 57 * The size is limited so it doesn't encroach into reserved MMIO space (e.g., 58 * APIC, HPET, MSI). 59 * 60 * It is allocated in page-multiple blocks on a first-come first-serve basis, 61 * from high to low, during initialization, and does not change at runtime. 62 */ 63 static char *romptr; /* Pointer to userspace-mapped bootrom region. */ 64 static vm_paddr_t gpa_base; /* GPA of low end of region. */ 65 static vm_paddr_t gpa_allocbot; /* Low GPA of free region. */ 66 static vm_paddr_t gpa_alloctop; /* High GPA, minus 1, of free region. */ 67 68 #define CFI_BCS_WRITE_BYTE 0x10 69 #define CFI_BCS_CLEAR_STATUS 0x50 70 #define CFI_BCS_READ_STATUS 0x70 71 #define CFI_BCS_READ_ARRAY 0xff 72 73 static struct bootrom_var_state { 74 uint8_t *mmap; 75 uint64_t gpa; 76 off_t size; 77 uint8_t cmd; 78 } var = { NULL, 0, 0, CFI_BCS_READ_ARRAY }; 79 80 /* 81 * Emulate just those CFI basic commands that will convince EDK II 82 * that the Firmware Volume area is writable and persistent. 83 */ 84 static int 85 bootrom_var_mem_handler(struct vcpu *vcpu __unused, int dir, uint64_t addr, 86 int size, uint64_t *val, void *arg1 __unused, long arg2 __unused) 87 { 88 off_t offset; 89 90 offset = addr - var.gpa; 91 if (offset + size > var.size || offset < 0 || offset + size <= offset) 92 return (EINVAL); 93 94 if (dir == MEM_F_WRITE) { 95 switch (var.cmd) { 96 case CFI_BCS_WRITE_BYTE: 97 memcpy(var.mmap + offset, val, size); 98 var.cmd = CFI_BCS_READ_ARRAY; 99 break; 100 default: 101 var.cmd = *(uint8_t *)val; 102 } 103 } else { 104 switch (var.cmd) { 105 case CFI_BCS_CLEAR_STATUS: 106 case CFI_BCS_READ_STATUS: 107 memset(val, 0, size); 108 var.cmd = CFI_BCS_READ_ARRAY; 109 break; 110 default: 111 memcpy(val, var.mmap + offset, size); 112 break; 113 } 114 } 115 return (0); 116 } 117 118 void 119 init_bootrom(struct vmctx *ctx) 120 { 121 vm_paddr_t highmem; 122 123 romptr = vm_create_devmem(ctx, VM_BOOTROM, "bootrom", BOOTROM_SIZE); 124 if (romptr == MAP_FAILED) 125 err(4, "%s: vm_create_devmem", __func__); 126 highmem = vm_get_highmem_base(ctx); 127 gpa_base = highmem - BOOTROM_SIZE; 128 gpa_allocbot = gpa_base; 129 gpa_alloctop = highmem - 1; 130 } 131 132 int 133 bootrom_alloc(struct vmctx *ctx, size_t len, int prot, int flags, 134 char **region_out, uint64_t *gpa_out) 135 { 136 static const int bootrom_valid_flags = BOOTROM_ALLOC_TOP; 137 138 vm_paddr_t gpa; 139 vm_ooffset_t segoff; 140 141 if (flags & ~bootrom_valid_flags) { 142 warnx("%s: Invalid flags: %x", __func__, 143 flags & ~bootrom_valid_flags); 144 return (EINVAL); 145 } 146 if (prot & ~_PROT_ALL) { 147 warnx("%s: Invalid protection: %x", __func__, 148 prot & ~_PROT_ALL); 149 return (EINVAL); 150 } 151 152 if (len == 0 || len > BOOTROM_SIZE) { 153 warnx("ROM size %zu is invalid", len); 154 return (EINVAL); 155 } 156 if (len & PAGE_MASK) { 157 warnx("ROM size %zu is not a multiple of the page size", 158 len); 159 return (EINVAL); 160 } 161 162 if (flags & BOOTROM_ALLOC_TOP) { 163 gpa = (gpa_alloctop - len) + 1; 164 if (gpa < gpa_allocbot) { 165 warnx("No room for %zu ROM in bootrom region", len); 166 return (ENOMEM); 167 } 168 } else { 169 gpa = gpa_allocbot; 170 if (gpa > (gpa_alloctop - len) + 1) { 171 warnx("No room for %zu ROM in bootrom region", len); 172 return (ENOMEM); 173 } 174 } 175 176 segoff = gpa - gpa_base; 177 if (vm_mmap_memseg(ctx, gpa, VM_BOOTROM, segoff, len, prot) != 0) { 178 int serrno = errno; 179 warn("%s: vm_mmap_mapseg", __func__); 180 return (serrno); 181 } 182 183 if (flags & BOOTROM_ALLOC_TOP) 184 gpa_alloctop = gpa - 1; 185 else 186 gpa_allocbot = gpa + len; 187 188 *region_out = romptr + segoff; 189 if (gpa_out != NULL) 190 *gpa_out = gpa; 191 return (0); 192 } 193 194 int 195 bootrom_loadrom(struct vmctx *ctx, const nvlist_t *nvl) 196 { 197 struct stat sbuf; 198 ssize_t rlen; 199 off_t rom_size, var_size, total_size; 200 char *ptr, *romfile; 201 int fd, varfd, i, rv; 202 const char *bootrom, *varfile; 203 204 rv = -1; 205 varfd = -1; 206 207 bootrom = get_config_value_node(nvl, "bootrom"); 208 if (bootrom == NULL) { 209 return (-1); 210 } 211 212 /* 213 * get_config_value_node may use a thread local buffer to return 214 * variables. So, when we query the second variable, the first variable 215 * might get overwritten. For that reason, the bootrom should be 216 * duplicated. 217 */ 218 romfile = strdup(bootrom); 219 if (romfile == NULL) { 220 return (-1); 221 } 222 223 fd = open(romfile, O_RDONLY); 224 if (fd < 0) { 225 EPRINTLN("Error opening bootrom \"%s\": %s", 226 romfile, strerror(errno)); 227 goto done; 228 } 229 230 if (fstat(fd, &sbuf) < 0) { 231 EPRINTLN("Could not fstat bootrom file \"%s\": %s", romfile, 232 strerror(errno)); 233 goto done; 234 } 235 236 rom_size = sbuf.st_size; 237 238 varfile = get_config_value_node(nvl, "bootvars"); 239 var_size = 0; 240 if (varfile != NULL) { 241 varfd = open(varfile, O_RDWR); 242 if (varfd < 0) { 243 EPRINTLN("Error opening bootrom variable file " 244 "\"%s\": %s", varfile, strerror(errno)); 245 goto done; 246 } 247 248 if (fstat(varfd, &sbuf) < 0) { 249 EPRINTLN( 250 "Could not fstat bootrom variable file \"%s\": %s", 251 varfile, strerror(errno)); 252 goto done; 253 } 254 255 var_size = sbuf.st_size; 256 } 257 258 if (var_size > BOOTROM_SIZE || 259 (var_size != 0 && var_size < PAGE_SIZE)) { 260 EPRINTLN("Invalid bootrom variable size %ld", 261 var_size); 262 goto done; 263 } 264 265 total_size = rom_size + var_size; 266 267 if (total_size > BOOTROM_SIZE) { 268 EPRINTLN("Invalid bootrom and variable aggregate size %ld", 269 total_size); 270 goto done; 271 } 272 273 /* Map the bootrom into the guest address space */ 274 if (bootrom_alloc(ctx, rom_size, PROT_READ | PROT_EXEC, 275 BOOTROM_ALLOC_TOP, &ptr, NULL) != 0) { 276 goto done; 277 } 278 279 /* Read 'romfile' into the guest address space */ 280 for (i = 0; i < rom_size / PAGE_SIZE; i++) { 281 rlen = read(fd, ptr + i * PAGE_SIZE, PAGE_SIZE); 282 if (rlen != PAGE_SIZE) { 283 EPRINTLN("Incomplete read of page %d of bootrom " 284 "file %s: %ld bytes", i, romfile, rlen); 285 goto done; 286 } 287 } 288 289 if (varfd >= 0) { 290 var.mmap = mmap(NULL, var_size, PROT_READ | PROT_WRITE, 291 MAP_SHARED, varfd, 0); 292 if (var.mmap == MAP_FAILED) 293 goto done; 294 var.size = var_size; 295 var.gpa = (gpa_alloctop - var_size) + 1; 296 gpa_alloctop = var.gpa - 1; 297 rv = register_mem(&(struct mem_range){ 298 .name = "bootrom variable", 299 .flags = MEM_F_RW, 300 .handler = bootrom_var_mem_handler, 301 .base = var.gpa, 302 .size = var.size, 303 }); 304 if (rv != 0) 305 goto done; 306 } 307 308 rv = 0; 309 done: 310 if (varfd >= 0) 311 close(varfd); 312 if (fd >= 0) 313 close(fd); 314 free(romfile); 315 return (rv); 316 } 317