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 romptr = vm_create_devmem(ctx, VM_BOOTROM, "bootrom", BOOTROM_SIZE); 122 if (romptr == MAP_FAILED) 123 err(4, "%s: vm_create_devmem", __func__); 124 gpa_base = (1ULL << 32) - BOOTROM_SIZE; 125 gpa_allocbot = gpa_base; 126 gpa_alloctop = (1ULL << 32) - 1; 127 } 128 129 int 130 bootrom_alloc(struct vmctx *ctx, size_t len, int prot, int flags, 131 char **region_out, uint64_t *gpa_out) 132 { 133 static const int bootrom_valid_flags = BOOTROM_ALLOC_TOP; 134 135 vm_paddr_t gpa; 136 vm_ooffset_t segoff; 137 138 if (flags & ~bootrom_valid_flags) { 139 warnx("%s: Invalid flags: %x", __func__, 140 flags & ~bootrom_valid_flags); 141 return (EINVAL); 142 } 143 if (prot & ~_PROT_ALL) { 144 warnx("%s: Invalid protection: %x", __func__, 145 prot & ~_PROT_ALL); 146 return (EINVAL); 147 } 148 149 if (len == 0 || len > BOOTROM_SIZE) { 150 warnx("ROM size %zu is invalid", len); 151 return (EINVAL); 152 } 153 if (len & PAGE_MASK) { 154 warnx("ROM size %zu is not a multiple of the page size", 155 len); 156 return (EINVAL); 157 } 158 159 if (flags & BOOTROM_ALLOC_TOP) { 160 gpa = (gpa_alloctop - len) + 1; 161 if (gpa < gpa_allocbot) { 162 warnx("No room for %zu ROM in bootrom region", len); 163 return (ENOMEM); 164 } 165 } else { 166 gpa = gpa_allocbot; 167 if (gpa > (gpa_alloctop - len) + 1) { 168 warnx("No room for %zu ROM in bootrom region", len); 169 return (ENOMEM); 170 } 171 } 172 173 segoff = gpa - gpa_base; 174 if (vm_mmap_memseg(ctx, gpa, VM_BOOTROM, segoff, len, prot) != 0) { 175 int serrno = errno; 176 warn("%s: vm_mmap_mapseg", __func__); 177 return (serrno); 178 } 179 180 if (flags & BOOTROM_ALLOC_TOP) 181 gpa_alloctop = gpa - 1; 182 else 183 gpa_allocbot = gpa + len; 184 185 *region_out = romptr + segoff; 186 if (gpa_out != NULL) 187 *gpa_out = gpa; 188 return (0); 189 } 190 191 int 192 bootrom_loadrom(struct vmctx *ctx, const nvlist_t *nvl) 193 { 194 struct stat sbuf; 195 ssize_t rlen; 196 off_t rom_size, var_size, total_size; 197 char *ptr, *romfile; 198 int fd, varfd, i, rv; 199 const char *bootrom, *varfile; 200 201 rv = -1; 202 varfd = -1; 203 204 bootrom = get_config_value_node(nvl, "bootrom"); 205 if (bootrom == NULL) { 206 return (-1); 207 } 208 209 /* 210 * get_config_value_node may use a thread local buffer to return 211 * variables. So, when we query the second variable, the first variable 212 * might get overwritten. For that reason, the bootrom should be 213 * duplicated. 214 */ 215 romfile = strdup(bootrom); 216 if (romfile == NULL) { 217 return (-1); 218 } 219 220 fd = open(romfile, O_RDONLY); 221 if (fd < 0) { 222 EPRINTLN("Error opening bootrom \"%s\": %s", 223 romfile, strerror(errno)); 224 goto done; 225 } 226 227 if (fstat(fd, &sbuf) < 0) { 228 EPRINTLN("Could not fstat bootrom file \"%s\": %s", romfile, 229 strerror(errno)); 230 goto done; 231 } 232 233 rom_size = sbuf.st_size; 234 235 varfile = get_config_value_node(nvl, "bootvars"); 236 var_size = 0; 237 if (varfile != NULL) { 238 varfd = open(varfile, O_RDWR); 239 if (varfd < 0) { 240 EPRINTLN("Error opening bootrom variable file " 241 "\"%s\": %s", varfile, strerror(errno)); 242 goto done; 243 } 244 245 if (fstat(varfd, &sbuf) < 0) { 246 EPRINTLN( 247 "Could not fstat bootrom variable file \"%s\": %s", 248 varfile, strerror(errno)); 249 goto done; 250 } 251 252 var_size = sbuf.st_size; 253 } 254 255 if (var_size > BOOTROM_SIZE || 256 (var_size != 0 && var_size < PAGE_SIZE)) { 257 EPRINTLN("Invalid bootrom variable size %ld", 258 var_size); 259 goto done; 260 } 261 262 total_size = rom_size + var_size; 263 264 if (total_size > BOOTROM_SIZE) { 265 EPRINTLN("Invalid bootrom and variable aggregate size %ld", 266 total_size); 267 goto done; 268 } 269 270 /* Map the bootrom into the guest address space */ 271 if (bootrom_alloc(ctx, rom_size, PROT_READ | PROT_EXEC, 272 BOOTROM_ALLOC_TOP, &ptr, NULL) != 0) { 273 goto done; 274 } 275 276 /* Read 'romfile' into the guest address space */ 277 for (i = 0; i < rom_size / PAGE_SIZE; i++) { 278 rlen = read(fd, ptr + i * PAGE_SIZE, PAGE_SIZE); 279 if (rlen != PAGE_SIZE) { 280 EPRINTLN("Incomplete read of page %d of bootrom " 281 "file %s: %ld bytes", i, romfile, rlen); 282 goto done; 283 } 284 } 285 286 if (varfd >= 0) { 287 var.mmap = mmap(NULL, var_size, PROT_READ | PROT_WRITE, 288 MAP_SHARED, varfd, 0); 289 if (var.mmap == MAP_FAILED) 290 goto done; 291 var.size = var_size; 292 var.gpa = (gpa_alloctop - var_size) + 1; 293 gpa_alloctop = var.gpa - 1; 294 rv = register_mem(&(struct mem_range){ 295 .name = "bootrom variable", 296 .flags = MEM_F_RW, 297 .handler = bootrom_var_mem_handler, 298 .base = var.gpa, 299 .size = var.size, 300 }); 301 if (rv != 0) 302 goto done; 303 } 304 305 rv = 0; 306 done: 307 if (varfd >= 0) 308 close(varfd); 309 if (fd >= 0) 310 close(fd); 311 free(romfile); 312 return (rv); 313 } 314