1 /* 2 * QEMU SEV support 3 * 4 * Copyright Advanced Micro Devices 2016-2018 5 * 6 * Author: 7 * Brijesh Singh <brijesh.singh@amd.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 * 12 */ 13 14 #include "qemu/osdep.h" 15 16 #include <linux/kvm.h> 17 #include <linux/psp-sev.h> 18 19 #include <sys/ioctl.h> 20 21 #include "qapi/error.h" 22 #include "qom/object_interfaces.h" 23 #include "qemu/base64.h" 24 #include "qemu/module.h" 25 #include "qemu/uuid.h" 26 #include "crypto/hash.h" 27 #include "sysemu/kvm.h" 28 #include "sev.h" 29 #include "sysemu/sysemu.h" 30 #include "sysemu/runstate.h" 31 #include "trace.h" 32 #include "migration/blocker.h" 33 #include "qom/object.h" 34 #include "monitor/monitor.h" 35 #include "monitor/hmp-target.h" 36 #include "qapi/qapi-commands-misc-target.h" 37 #include "qapi/qmp/qerror.h" 38 #include "exec/confidential-guest-support.h" 39 #include "hw/i386/pc.h" 40 #include "exec/address-spaces.h" 41 42 #define TYPE_SEV_GUEST "sev-guest" 43 OBJECT_DECLARE_SIMPLE_TYPE(SevGuestState, SEV_GUEST) 44 45 46 /** 47 * SevGuestState: 48 * 49 * The SevGuestState object is used for creating and managing a SEV 50 * guest. 51 * 52 * # $QEMU \ 53 * -object sev-guest,id=sev0 \ 54 * -machine ...,memory-encryption=sev0 55 */ 56 struct SevGuestState { 57 ConfidentialGuestSupport parent_obj; 58 59 /* configuration parameters */ 60 char *sev_device; 61 uint32_t policy; 62 char *dh_cert_file; 63 char *session_file; 64 uint32_t cbitpos; 65 uint32_t reduced_phys_bits; 66 bool kernel_hashes; 67 68 /* runtime state */ 69 uint32_t handle; 70 uint8_t api_major; 71 uint8_t api_minor; 72 uint8_t build_id; 73 int sev_fd; 74 SevState state; 75 gchar *measurement; 76 77 uint32_t reset_cs; 78 uint32_t reset_ip; 79 bool reset_data_valid; 80 }; 81 82 #define DEFAULT_GUEST_POLICY 0x1 /* disable debug */ 83 #define DEFAULT_SEV_DEVICE "/dev/sev" 84 85 #define SEV_INFO_BLOCK_GUID "00f771de-1a7e-4fcb-890e-68c77e2fb44e" 86 typedef struct __attribute__((__packed__)) SevInfoBlock { 87 /* SEV-ES Reset Vector Address */ 88 uint32_t reset_addr; 89 } SevInfoBlock; 90 91 #define SEV_HASH_TABLE_RV_GUID "7255371f-3a3b-4b04-927b-1da6efa8d454" 92 typedef struct QEMU_PACKED SevHashTableDescriptor { 93 /* SEV hash table area guest address */ 94 uint32_t base; 95 /* SEV hash table area size (in bytes) */ 96 uint32_t size; 97 } SevHashTableDescriptor; 98 99 /* hard code sha256 digest size */ 100 #define HASH_SIZE 32 101 102 typedef struct QEMU_PACKED SevHashTableEntry { 103 QemuUUID guid; 104 uint16_t len; 105 uint8_t hash[HASH_SIZE]; 106 } SevHashTableEntry; 107 108 typedef struct QEMU_PACKED SevHashTable { 109 QemuUUID guid; 110 uint16_t len; 111 SevHashTableEntry cmdline; 112 SevHashTableEntry initrd; 113 SevHashTableEntry kernel; 114 } SevHashTable; 115 116 /* 117 * Data encrypted by sev_encrypt_flash() must be padded to a multiple of 118 * 16 bytes. 119 */ 120 typedef struct QEMU_PACKED PaddedSevHashTable { 121 SevHashTable ht; 122 uint8_t padding[ROUND_UP(sizeof(SevHashTable), 16) - sizeof(SevHashTable)]; 123 } PaddedSevHashTable; 124 125 QEMU_BUILD_BUG_ON(sizeof(PaddedSevHashTable) % 16 != 0); 126 127 static SevGuestState *sev_guest; 128 static Error *sev_mig_blocker; 129 130 static const char *const sev_fw_errlist[] = { 131 [SEV_RET_SUCCESS] = "", 132 [SEV_RET_INVALID_PLATFORM_STATE] = "Platform state is invalid", 133 [SEV_RET_INVALID_GUEST_STATE] = "Guest state is invalid", 134 [SEV_RET_INAVLID_CONFIG] = "Platform configuration is invalid", 135 [SEV_RET_INVALID_LEN] = "Buffer too small", 136 [SEV_RET_ALREADY_OWNED] = "Platform is already owned", 137 [SEV_RET_INVALID_CERTIFICATE] = "Certificate is invalid", 138 [SEV_RET_POLICY_FAILURE] = "Policy is not allowed", 139 [SEV_RET_INACTIVE] = "Guest is not active", 140 [SEV_RET_INVALID_ADDRESS] = "Invalid address", 141 [SEV_RET_BAD_SIGNATURE] = "Bad signature", 142 [SEV_RET_BAD_MEASUREMENT] = "Bad measurement", 143 [SEV_RET_ASID_OWNED] = "ASID is already owned", 144 [SEV_RET_INVALID_ASID] = "Invalid ASID", 145 [SEV_RET_WBINVD_REQUIRED] = "WBINVD is required", 146 [SEV_RET_DFFLUSH_REQUIRED] = "DF_FLUSH is required", 147 [SEV_RET_INVALID_GUEST] = "Guest handle is invalid", 148 [SEV_RET_INVALID_COMMAND] = "Invalid command", 149 [SEV_RET_ACTIVE] = "Guest is active", 150 [SEV_RET_HWSEV_RET_PLATFORM] = "Hardware error", 151 [SEV_RET_HWSEV_RET_UNSAFE] = "Hardware unsafe", 152 [SEV_RET_UNSUPPORTED] = "Feature not supported", 153 [SEV_RET_INVALID_PARAM] = "Invalid parameter", 154 [SEV_RET_RESOURCE_LIMIT] = "Required firmware resource depleted", 155 [SEV_RET_SECURE_DATA_INVALID] = "Part-specific integrity check failure", 156 }; 157 158 #define SEV_FW_MAX_ERROR ARRAY_SIZE(sev_fw_errlist) 159 160 static int 161 sev_ioctl(int fd, int cmd, void *data, int *error) 162 { 163 int r; 164 struct kvm_sev_cmd input; 165 166 memset(&input, 0x0, sizeof(input)); 167 168 input.id = cmd; 169 input.sev_fd = fd; 170 input.data = (__u64)(unsigned long)data; 171 172 r = kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_OP, &input); 173 174 if (error) { 175 *error = input.error; 176 } 177 178 return r; 179 } 180 181 static int 182 sev_platform_ioctl(int fd, int cmd, void *data, int *error) 183 { 184 int r; 185 struct sev_issue_cmd arg; 186 187 arg.cmd = cmd; 188 arg.data = (unsigned long)data; 189 r = ioctl(fd, SEV_ISSUE_CMD, &arg); 190 if (error) { 191 *error = arg.error; 192 } 193 194 return r; 195 } 196 197 static const char * 198 fw_error_to_str(int code) 199 { 200 if (code < 0 || code >= SEV_FW_MAX_ERROR) { 201 return "unknown error"; 202 } 203 204 return sev_fw_errlist[code]; 205 } 206 207 static bool 208 sev_check_state(const SevGuestState *sev, SevState state) 209 { 210 assert(sev); 211 return sev->state == state ? true : false; 212 } 213 214 static void 215 sev_set_guest_state(SevGuestState *sev, SevState new_state) 216 { 217 assert(new_state < SEV_STATE__MAX); 218 assert(sev); 219 220 trace_kvm_sev_change_state(SevState_str(sev->state), 221 SevState_str(new_state)); 222 sev->state = new_state; 223 } 224 225 static void 226 sev_ram_block_added(RAMBlockNotifier *n, void *host, size_t size, 227 size_t max_size) 228 { 229 int r; 230 struct kvm_enc_region range; 231 ram_addr_t offset; 232 MemoryRegion *mr; 233 234 /* 235 * The RAM device presents a memory region that should be treated 236 * as IO region and should not be pinned. 237 */ 238 mr = memory_region_from_host(host, &offset); 239 if (mr && memory_region_is_ram_device(mr)) { 240 return; 241 } 242 243 range.addr = (__u64)(unsigned long)host; 244 range.size = max_size; 245 246 trace_kvm_memcrypt_register_region(host, max_size); 247 r = kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_REG_REGION, &range); 248 if (r) { 249 error_report("%s: failed to register region (%p+%#zx) error '%s'", 250 __func__, host, max_size, strerror(errno)); 251 exit(1); 252 } 253 } 254 255 static void 256 sev_ram_block_removed(RAMBlockNotifier *n, void *host, size_t size, 257 size_t max_size) 258 { 259 int r; 260 struct kvm_enc_region range; 261 ram_addr_t offset; 262 MemoryRegion *mr; 263 264 /* 265 * The RAM device presents a memory region that should be treated 266 * as IO region and should not have been pinned. 267 */ 268 mr = memory_region_from_host(host, &offset); 269 if (mr && memory_region_is_ram_device(mr)) { 270 return; 271 } 272 273 range.addr = (__u64)(unsigned long)host; 274 range.size = max_size; 275 276 trace_kvm_memcrypt_unregister_region(host, max_size); 277 r = kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_UNREG_REGION, &range); 278 if (r) { 279 error_report("%s: failed to unregister region (%p+%#zx)", 280 __func__, host, max_size); 281 } 282 } 283 284 static struct RAMBlockNotifier sev_ram_notifier = { 285 .ram_block_added = sev_ram_block_added, 286 .ram_block_removed = sev_ram_block_removed, 287 }; 288 289 static void 290 sev_guest_finalize(Object *obj) 291 { 292 } 293 294 static char * 295 sev_guest_get_session_file(Object *obj, Error **errp) 296 { 297 SevGuestState *s = SEV_GUEST(obj); 298 299 return s->session_file ? g_strdup(s->session_file) : NULL; 300 } 301 302 static void 303 sev_guest_set_session_file(Object *obj, const char *value, Error **errp) 304 { 305 SevGuestState *s = SEV_GUEST(obj); 306 307 s->session_file = g_strdup(value); 308 } 309 310 static char * 311 sev_guest_get_dh_cert_file(Object *obj, Error **errp) 312 { 313 SevGuestState *s = SEV_GUEST(obj); 314 315 return g_strdup(s->dh_cert_file); 316 } 317 318 static void 319 sev_guest_set_dh_cert_file(Object *obj, const char *value, Error **errp) 320 { 321 SevGuestState *s = SEV_GUEST(obj); 322 323 s->dh_cert_file = g_strdup(value); 324 } 325 326 static char * 327 sev_guest_get_sev_device(Object *obj, Error **errp) 328 { 329 SevGuestState *sev = SEV_GUEST(obj); 330 331 return g_strdup(sev->sev_device); 332 } 333 334 static void 335 sev_guest_set_sev_device(Object *obj, const char *value, Error **errp) 336 { 337 SevGuestState *sev = SEV_GUEST(obj); 338 339 sev->sev_device = g_strdup(value); 340 } 341 342 static bool sev_guest_get_kernel_hashes(Object *obj, Error **errp) 343 { 344 SevGuestState *sev = SEV_GUEST(obj); 345 346 return sev->kernel_hashes; 347 } 348 349 static void sev_guest_set_kernel_hashes(Object *obj, bool value, Error **errp) 350 { 351 SevGuestState *sev = SEV_GUEST(obj); 352 353 sev->kernel_hashes = value; 354 } 355 356 static void 357 sev_guest_class_init(ObjectClass *oc, void *data) 358 { 359 object_class_property_add_str(oc, "sev-device", 360 sev_guest_get_sev_device, 361 sev_guest_set_sev_device); 362 object_class_property_set_description(oc, "sev-device", 363 "SEV device to use"); 364 object_class_property_add_str(oc, "dh-cert-file", 365 sev_guest_get_dh_cert_file, 366 sev_guest_set_dh_cert_file); 367 object_class_property_set_description(oc, "dh-cert-file", 368 "guest owners DH certificate (encoded with base64)"); 369 object_class_property_add_str(oc, "session-file", 370 sev_guest_get_session_file, 371 sev_guest_set_session_file); 372 object_class_property_set_description(oc, "session-file", 373 "guest owners session parameters (encoded with base64)"); 374 object_class_property_add_bool(oc, "kernel-hashes", 375 sev_guest_get_kernel_hashes, 376 sev_guest_set_kernel_hashes); 377 object_class_property_set_description(oc, "kernel-hashes", 378 "add kernel hashes to guest firmware for measured Linux boot"); 379 } 380 381 static void 382 sev_guest_instance_init(Object *obj) 383 { 384 SevGuestState *sev = SEV_GUEST(obj); 385 386 sev->sev_device = g_strdup(DEFAULT_SEV_DEVICE); 387 sev->policy = DEFAULT_GUEST_POLICY; 388 object_property_add_uint32_ptr(obj, "policy", &sev->policy, 389 OBJ_PROP_FLAG_READWRITE); 390 object_property_add_uint32_ptr(obj, "handle", &sev->handle, 391 OBJ_PROP_FLAG_READWRITE); 392 object_property_add_uint32_ptr(obj, "cbitpos", &sev->cbitpos, 393 OBJ_PROP_FLAG_READWRITE); 394 object_property_add_uint32_ptr(obj, "reduced-phys-bits", 395 &sev->reduced_phys_bits, 396 OBJ_PROP_FLAG_READWRITE); 397 } 398 399 /* sev guest info */ 400 static const TypeInfo sev_guest_info = { 401 .parent = TYPE_CONFIDENTIAL_GUEST_SUPPORT, 402 .name = TYPE_SEV_GUEST, 403 .instance_size = sizeof(SevGuestState), 404 .instance_finalize = sev_guest_finalize, 405 .class_init = sev_guest_class_init, 406 .instance_init = sev_guest_instance_init, 407 .interfaces = (InterfaceInfo[]) { 408 { TYPE_USER_CREATABLE }, 409 { } 410 } 411 }; 412 413 bool 414 sev_enabled(void) 415 { 416 return !!sev_guest; 417 } 418 419 bool 420 sev_es_enabled(void) 421 { 422 return sev_enabled() && (sev_guest->policy & SEV_POLICY_ES); 423 } 424 425 uint32_t 426 sev_get_cbit_position(void) 427 { 428 return sev_guest ? sev_guest->cbitpos : 0; 429 } 430 431 uint32_t 432 sev_get_reduced_phys_bits(void) 433 { 434 return sev_guest ? sev_guest->reduced_phys_bits : 0; 435 } 436 437 static SevInfo *sev_get_info(void) 438 { 439 SevInfo *info; 440 441 info = g_new0(SevInfo, 1); 442 info->enabled = sev_enabled(); 443 444 if (info->enabled) { 445 info->api_major = sev_guest->api_major; 446 info->api_minor = sev_guest->api_minor; 447 info->build_id = sev_guest->build_id; 448 info->policy = sev_guest->policy; 449 info->state = sev_guest->state; 450 info->handle = sev_guest->handle; 451 } 452 453 return info; 454 } 455 456 SevInfo *qmp_query_sev(Error **errp) 457 { 458 SevInfo *info; 459 460 info = sev_get_info(); 461 if (!info) { 462 error_setg(errp, "SEV feature is not available"); 463 return NULL; 464 } 465 466 return info; 467 } 468 469 void hmp_info_sev(Monitor *mon, const QDict *qdict) 470 { 471 SevInfo *info = sev_get_info(); 472 473 if (info && info->enabled) { 474 monitor_printf(mon, "handle: %d\n", info->handle); 475 monitor_printf(mon, "state: %s\n", SevState_str(info->state)); 476 monitor_printf(mon, "build: %d\n", info->build_id); 477 monitor_printf(mon, "api version: %d.%d\n", 478 info->api_major, info->api_minor); 479 monitor_printf(mon, "debug: %s\n", 480 info->policy & SEV_POLICY_NODBG ? "off" : "on"); 481 monitor_printf(mon, "key-sharing: %s\n", 482 info->policy & SEV_POLICY_NOKS ? "off" : "on"); 483 } else { 484 monitor_printf(mon, "SEV is not enabled\n"); 485 } 486 487 qapi_free_SevInfo(info); 488 } 489 490 static int 491 sev_get_pdh_info(int fd, guchar **pdh, size_t *pdh_len, guchar **cert_chain, 492 size_t *cert_chain_len, Error **errp) 493 { 494 guchar *pdh_data = NULL; 495 guchar *cert_chain_data = NULL; 496 struct sev_user_data_pdh_cert_export export = {}; 497 int err, r; 498 499 /* query the certificate length */ 500 r = sev_platform_ioctl(fd, SEV_PDH_CERT_EXPORT, &export, &err); 501 if (r < 0) { 502 if (err != SEV_RET_INVALID_LEN) { 503 error_setg(errp, "SEV: Failed to export PDH cert" 504 " ret=%d fw_err=%d (%s)", 505 r, err, fw_error_to_str(err)); 506 return 1; 507 } 508 } 509 510 pdh_data = g_new(guchar, export.pdh_cert_len); 511 cert_chain_data = g_new(guchar, export.cert_chain_len); 512 export.pdh_cert_address = (unsigned long)pdh_data; 513 export.cert_chain_address = (unsigned long)cert_chain_data; 514 515 r = sev_platform_ioctl(fd, SEV_PDH_CERT_EXPORT, &export, &err); 516 if (r < 0) { 517 error_setg(errp, "SEV: Failed to export PDH cert ret=%d fw_err=%d (%s)", 518 r, err, fw_error_to_str(err)); 519 goto e_free; 520 } 521 522 *pdh = pdh_data; 523 *pdh_len = export.pdh_cert_len; 524 *cert_chain = cert_chain_data; 525 *cert_chain_len = export.cert_chain_len; 526 return 0; 527 528 e_free: 529 g_free(pdh_data); 530 g_free(cert_chain_data); 531 return 1; 532 } 533 534 static SevCapability *sev_get_capabilities(Error **errp) 535 { 536 SevCapability *cap = NULL; 537 guchar *pdh_data = NULL; 538 guchar *cert_chain_data = NULL; 539 size_t pdh_len = 0, cert_chain_len = 0; 540 uint32_t ebx; 541 int fd; 542 543 if (!kvm_enabled()) { 544 error_setg(errp, "KVM not enabled"); 545 return NULL; 546 } 547 if (kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_OP, NULL) < 0) { 548 error_setg(errp, "SEV is not enabled in KVM"); 549 return NULL; 550 } 551 552 fd = open(DEFAULT_SEV_DEVICE, O_RDWR); 553 if (fd < 0) { 554 error_setg_errno(errp, errno, "SEV: Failed to open %s", 555 DEFAULT_SEV_DEVICE); 556 return NULL; 557 } 558 559 if (sev_get_pdh_info(fd, &pdh_data, &pdh_len, 560 &cert_chain_data, &cert_chain_len, errp)) { 561 goto out; 562 } 563 564 cap = g_new0(SevCapability, 1); 565 cap->pdh = g_base64_encode(pdh_data, pdh_len); 566 cap->cert_chain = g_base64_encode(cert_chain_data, cert_chain_len); 567 568 host_cpuid(0x8000001F, 0, NULL, &ebx, NULL, NULL); 569 cap->cbitpos = ebx & 0x3f; 570 571 /* 572 * When SEV feature is enabled, we loose one bit in guest physical 573 * addressing. 574 */ 575 cap->reduced_phys_bits = 1; 576 577 out: 578 g_free(pdh_data); 579 g_free(cert_chain_data); 580 close(fd); 581 return cap; 582 } 583 584 SevCapability *qmp_query_sev_capabilities(Error **errp) 585 { 586 return sev_get_capabilities(errp); 587 } 588 589 static SevAttestationReport *sev_get_attestation_report(const char *mnonce, 590 Error **errp) 591 { 592 struct kvm_sev_attestation_report input = {}; 593 SevAttestationReport *report = NULL; 594 SevGuestState *sev = sev_guest; 595 g_autofree guchar *data = NULL; 596 g_autofree guchar *buf = NULL; 597 gsize len; 598 int err = 0, ret; 599 600 if (!sev_enabled()) { 601 error_setg(errp, "SEV is not enabled"); 602 return NULL; 603 } 604 605 /* lets decode the mnonce string */ 606 buf = g_base64_decode(mnonce, &len); 607 if (!buf) { 608 error_setg(errp, "SEV: failed to decode mnonce input"); 609 return NULL; 610 } 611 612 /* verify the input mnonce length */ 613 if (len != sizeof(input.mnonce)) { 614 error_setg(errp, "SEV: mnonce must be %zu bytes (got %" G_GSIZE_FORMAT ")", 615 sizeof(input.mnonce), len); 616 return NULL; 617 } 618 619 /* Query the report length */ 620 ret = sev_ioctl(sev->sev_fd, KVM_SEV_GET_ATTESTATION_REPORT, 621 &input, &err); 622 if (ret < 0) { 623 if (err != SEV_RET_INVALID_LEN) { 624 error_setg(errp, "SEV: Failed to query the attestation report" 625 " length ret=%d fw_err=%d (%s)", 626 ret, err, fw_error_to_str(err)); 627 return NULL; 628 } 629 } 630 631 data = g_malloc(input.len); 632 input.uaddr = (unsigned long)data; 633 memcpy(input.mnonce, buf, sizeof(input.mnonce)); 634 635 /* Query the report */ 636 ret = sev_ioctl(sev->sev_fd, KVM_SEV_GET_ATTESTATION_REPORT, 637 &input, &err); 638 if (ret) { 639 error_setg_errno(errp, errno, "SEV: Failed to get attestation report" 640 " ret=%d fw_err=%d (%s)", ret, err, fw_error_to_str(err)); 641 return NULL; 642 } 643 644 report = g_new0(SevAttestationReport, 1); 645 report->data = g_base64_encode(data, input.len); 646 647 trace_kvm_sev_attestation_report(mnonce, report->data); 648 649 return report; 650 } 651 652 SevAttestationReport *qmp_query_sev_attestation_report(const char *mnonce, 653 Error **errp) 654 { 655 return sev_get_attestation_report(mnonce, errp); 656 } 657 658 static int 659 sev_read_file_base64(const char *filename, guchar **data, gsize *len) 660 { 661 gsize sz; 662 g_autofree gchar *base64 = NULL; 663 GError *error = NULL; 664 665 if (!g_file_get_contents(filename, &base64, &sz, &error)) { 666 error_report("SEV: Failed to read '%s' (%s)", filename, error->message); 667 g_error_free(error); 668 return -1; 669 } 670 671 *data = g_base64_decode(base64, len); 672 return 0; 673 } 674 675 static int 676 sev_launch_start(SevGuestState *sev) 677 { 678 gsize sz; 679 int ret = 1; 680 int fw_error, rc; 681 struct kvm_sev_launch_start start = { 682 .handle = sev->handle, .policy = sev->policy 683 }; 684 guchar *session = NULL, *dh_cert = NULL; 685 686 if (sev->session_file) { 687 if (sev_read_file_base64(sev->session_file, &session, &sz) < 0) { 688 goto out; 689 } 690 start.session_uaddr = (unsigned long)session; 691 start.session_len = sz; 692 } 693 694 if (sev->dh_cert_file) { 695 if (sev_read_file_base64(sev->dh_cert_file, &dh_cert, &sz) < 0) { 696 goto out; 697 } 698 start.dh_uaddr = (unsigned long)dh_cert; 699 start.dh_len = sz; 700 } 701 702 trace_kvm_sev_launch_start(start.policy, session, dh_cert); 703 rc = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_START, &start, &fw_error); 704 if (rc < 0) { 705 error_report("%s: LAUNCH_START ret=%d fw_error=%d '%s'", 706 __func__, ret, fw_error, fw_error_to_str(fw_error)); 707 goto out; 708 } 709 710 sev_set_guest_state(sev, SEV_STATE_LAUNCH_UPDATE); 711 sev->handle = start.handle; 712 ret = 0; 713 714 out: 715 g_free(session); 716 g_free(dh_cert); 717 return ret; 718 } 719 720 static int 721 sev_launch_update_data(SevGuestState *sev, uint8_t *addr, uint64_t len) 722 { 723 int ret, fw_error; 724 struct kvm_sev_launch_update_data update; 725 726 if (!addr || !len) { 727 return 1; 728 } 729 730 update.uaddr = (__u64)(unsigned long)addr; 731 update.len = len; 732 trace_kvm_sev_launch_update_data(addr, len); 733 ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_UPDATE_DATA, 734 &update, &fw_error); 735 if (ret) { 736 error_report("%s: LAUNCH_UPDATE ret=%d fw_error=%d '%s'", 737 __func__, ret, fw_error, fw_error_to_str(fw_error)); 738 } 739 740 return ret; 741 } 742 743 static int 744 sev_launch_update_vmsa(SevGuestState *sev) 745 { 746 int ret, fw_error; 747 748 ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_UPDATE_VMSA, NULL, &fw_error); 749 if (ret) { 750 error_report("%s: LAUNCH_UPDATE_VMSA ret=%d fw_error=%d '%s'", 751 __func__, ret, fw_error, fw_error_to_str(fw_error)); 752 } 753 754 return ret; 755 } 756 757 static void 758 sev_launch_get_measure(Notifier *notifier, void *unused) 759 { 760 SevGuestState *sev = sev_guest; 761 int ret, error; 762 g_autofree guchar *data = NULL; 763 struct kvm_sev_launch_measure measurement = {}; 764 765 if (!sev_check_state(sev, SEV_STATE_LAUNCH_UPDATE)) { 766 return; 767 } 768 769 if (sev_es_enabled()) { 770 /* measure all the VM save areas before getting launch_measure */ 771 ret = sev_launch_update_vmsa(sev); 772 if (ret) { 773 exit(1); 774 } 775 } 776 777 /* query the measurement blob length */ 778 ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_MEASURE, 779 &measurement, &error); 780 if (!measurement.len) { 781 error_report("%s: LAUNCH_MEASURE ret=%d fw_error=%d '%s'", 782 __func__, ret, error, fw_error_to_str(errno)); 783 return; 784 } 785 786 data = g_new0(guchar, measurement.len); 787 measurement.uaddr = (unsigned long)data; 788 789 /* get the measurement blob */ 790 ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_MEASURE, 791 &measurement, &error); 792 if (ret) { 793 error_report("%s: LAUNCH_MEASURE ret=%d fw_error=%d '%s'", 794 __func__, ret, error, fw_error_to_str(errno)); 795 return; 796 } 797 798 sev_set_guest_state(sev, SEV_STATE_LAUNCH_SECRET); 799 800 /* encode the measurement value and emit the event */ 801 sev->measurement = g_base64_encode(data, measurement.len); 802 trace_kvm_sev_launch_measurement(sev->measurement); 803 } 804 805 static char *sev_get_launch_measurement(void) 806 { 807 if (sev_guest && 808 sev_guest->state >= SEV_STATE_LAUNCH_SECRET) { 809 return g_strdup(sev_guest->measurement); 810 } 811 812 return NULL; 813 } 814 815 SevLaunchMeasureInfo *qmp_query_sev_launch_measure(Error **errp) 816 { 817 char *data; 818 SevLaunchMeasureInfo *info; 819 820 data = sev_get_launch_measurement(); 821 if (!data) { 822 error_setg(errp, "SEV launch measurement is not available"); 823 return NULL; 824 } 825 826 info = g_malloc0(sizeof(*info)); 827 info->data = data; 828 829 return info; 830 } 831 832 static Notifier sev_machine_done_notify = { 833 .notify = sev_launch_get_measure, 834 }; 835 836 static void 837 sev_launch_finish(SevGuestState *sev) 838 { 839 int ret, error; 840 841 trace_kvm_sev_launch_finish(); 842 ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_FINISH, 0, &error); 843 if (ret) { 844 error_report("%s: LAUNCH_FINISH ret=%d fw_error=%d '%s'", 845 __func__, ret, error, fw_error_to_str(error)); 846 exit(1); 847 } 848 849 sev_set_guest_state(sev, SEV_STATE_RUNNING); 850 851 /* add migration blocker */ 852 error_setg(&sev_mig_blocker, 853 "SEV: Migration is not implemented"); 854 migrate_add_blocker(sev_mig_blocker, &error_fatal); 855 } 856 857 static void 858 sev_vm_state_change(void *opaque, bool running, RunState state) 859 { 860 SevGuestState *sev = opaque; 861 862 if (running) { 863 if (!sev_check_state(sev, SEV_STATE_RUNNING)) { 864 sev_launch_finish(sev); 865 } 866 } 867 } 868 869 int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) 870 { 871 SevGuestState *sev 872 = (SevGuestState *)object_dynamic_cast(OBJECT(cgs), TYPE_SEV_GUEST); 873 char *devname; 874 int ret, fw_error, cmd; 875 uint32_t ebx; 876 uint32_t host_cbitpos; 877 struct sev_user_data_status status = {}; 878 879 if (!sev) { 880 return 0; 881 } 882 883 ret = ram_block_discard_disable(true); 884 if (ret) { 885 error_report("%s: cannot disable RAM discard", __func__); 886 return -1; 887 } 888 889 sev_guest = sev; 890 sev->state = SEV_STATE_UNINIT; 891 892 host_cpuid(0x8000001F, 0, NULL, &ebx, NULL, NULL); 893 host_cbitpos = ebx & 0x3f; 894 895 if (host_cbitpos != sev->cbitpos) { 896 error_setg(errp, "%s: cbitpos check failed, host '%d' requested '%d'", 897 __func__, host_cbitpos, sev->cbitpos); 898 goto err; 899 } 900 901 if (sev->reduced_phys_bits < 1) { 902 error_setg(errp, "%s: reduced_phys_bits check failed, it should be >=1," 903 " requested '%d'", __func__, sev->reduced_phys_bits); 904 goto err; 905 } 906 907 devname = object_property_get_str(OBJECT(sev), "sev-device", NULL); 908 sev->sev_fd = open(devname, O_RDWR); 909 if (sev->sev_fd < 0) { 910 error_setg(errp, "%s: Failed to open %s '%s'", __func__, 911 devname, strerror(errno)); 912 g_free(devname); 913 goto err; 914 } 915 g_free(devname); 916 917 ret = sev_platform_ioctl(sev->sev_fd, SEV_PLATFORM_STATUS, &status, 918 &fw_error); 919 if (ret) { 920 error_setg(errp, "%s: failed to get platform status ret=%d " 921 "fw_error='%d: %s'", __func__, ret, fw_error, 922 fw_error_to_str(fw_error)); 923 goto err; 924 } 925 sev->build_id = status.build; 926 sev->api_major = status.api_major; 927 sev->api_minor = status.api_minor; 928 929 if (sev_es_enabled()) { 930 if (!kvm_kernel_irqchip_allowed()) { 931 error_report("%s: SEV-ES guests require in-kernel irqchip support", 932 __func__); 933 goto err; 934 } 935 936 if (!(status.flags & SEV_STATUS_FLAGS_CONFIG_ES)) { 937 error_report("%s: guest policy requires SEV-ES, but " 938 "host SEV-ES support unavailable", 939 __func__); 940 goto err; 941 } 942 cmd = KVM_SEV_ES_INIT; 943 } else { 944 cmd = KVM_SEV_INIT; 945 } 946 947 trace_kvm_sev_init(); 948 ret = sev_ioctl(sev->sev_fd, cmd, NULL, &fw_error); 949 if (ret) { 950 error_setg(errp, "%s: failed to initialize ret=%d fw_error=%d '%s'", 951 __func__, ret, fw_error, fw_error_to_str(fw_error)); 952 goto err; 953 } 954 955 ret = sev_launch_start(sev); 956 if (ret) { 957 error_setg(errp, "%s: failed to create encryption context", __func__); 958 goto err; 959 } 960 961 ram_block_notifier_add(&sev_ram_notifier); 962 qemu_add_machine_init_done_notifier(&sev_machine_done_notify); 963 qemu_add_vm_change_state_handler(sev_vm_state_change, sev); 964 965 cgs->ready = true; 966 967 return 0; 968 err: 969 sev_guest = NULL; 970 ram_block_discard_disable(false); 971 return -1; 972 } 973 974 int 975 sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp) 976 { 977 if (!sev_guest) { 978 return 0; 979 } 980 981 /* if SEV is in update state then encrypt the data else do nothing */ 982 if (sev_check_state(sev_guest, SEV_STATE_LAUNCH_UPDATE)) { 983 int ret = sev_launch_update_data(sev_guest, ptr, len); 984 if (ret < 0) { 985 error_setg(errp, "SEV: Failed to encrypt pflash rom"); 986 return ret; 987 } 988 } 989 990 return 0; 991 } 992 993 int sev_inject_launch_secret(const char *packet_hdr, const char *secret, 994 uint64_t gpa, Error **errp) 995 { 996 struct kvm_sev_launch_secret input; 997 g_autofree guchar *data = NULL, *hdr = NULL; 998 int error, ret = 1; 999 void *hva; 1000 gsize hdr_sz = 0, data_sz = 0; 1001 MemoryRegion *mr = NULL; 1002 1003 if (!sev_guest) { 1004 error_setg(errp, "SEV not enabled for guest"); 1005 return 1; 1006 } 1007 1008 /* secret can be injected only in this state */ 1009 if (!sev_check_state(sev_guest, SEV_STATE_LAUNCH_SECRET)) { 1010 error_setg(errp, "SEV: Not in correct state. (LSECRET) %x", 1011 sev_guest->state); 1012 return 1; 1013 } 1014 1015 hdr = g_base64_decode(packet_hdr, &hdr_sz); 1016 if (!hdr || !hdr_sz) { 1017 error_setg(errp, "SEV: Failed to decode sequence header"); 1018 return 1; 1019 } 1020 1021 data = g_base64_decode(secret, &data_sz); 1022 if (!data || !data_sz) { 1023 error_setg(errp, "SEV: Failed to decode data"); 1024 return 1; 1025 } 1026 1027 hva = gpa2hva(&mr, gpa, data_sz, errp); 1028 if (!hva) { 1029 error_prepend(errp, "SEV: Failed to calculate guest address: "); 1030 return 1; 1031 } 1032 1033 input.hdr_uaddr = (uint64_t)(unsigned long)hdr; 1034 input.hdr_len = hdr_sz; 1035 1036 input.trans_uaddr = (uint64_t)(unsigned long)data; 1037 input.trans_len = data_sz; 1038 1039 input.guest_uaddr = (uint64_t)(unsigned long)hva; 1040 input.guest_len = data_sz; 1041 1042 trace_kvm_sev_launch_secret(gpa, input.guest_uaddr, 1043 input.trans_uaddr, input.trans_len); 1044 1045 ret = sev_ioctl(sev_guest->sev_fd, KVM_SEV_LAUNCH_SECRET, 1046 &input, &error); 1047 if (ret) { 1048 error_setg(errp, "SEV: failed to inject secret ret=%d fw_error=%d '%s'", 1049 ret, error, fw_error_to_str(error)); 1050 return ret; 1051 } 1052 1053 return 0; 1054 } 1055 1056 #define SEV_SECRET_GUID "4c2eb361-7d9b-4cc3-8081-127c90d3d294" 1057 struct sev_secret_area { 1058 uint32_t base; 1059 uint32_t size; 1060 }; 1061 1062 void qmp_sev_inject_launch_secret(const char *packet_hdr, 1063 const char *secret, 1064 bool has_gpa, uint64_t gpa, 1065 Error **errp) 1066 { 1067 if (!sev_enabled()) { 1068 error_setg(errp, "SEV not enabled for guest"); 1069 return; 1070 } 1071 if (!has_gpa) { 1072 uint8_t *data; 1073 struct sev_secret_area *area; 1074 1075 if (!pc_system_ovmf_table_find(SEV_SECRET_GUID, &data, NULL)) { 1076 error_setg(errp, "SEV: no secret area found in OVMF," 1077 " gpa must be specified."); 1078 return; 1079 } 1080 area = (struct sev_secret_area *)data; 1081 gpa = area->base; 1082 } 1083 1084 sev_inject_launch_secret(packet_hdr, secret, gpa, errp); 1085 } 1086 1087 static int 1088 sev_es_parse_reset_block(SevInfoBlock *info, uint32_t *addr) 1089 { 1090 if (!info->reset_addr) { 1091 error_report("SEV-ES reset address is zero"); 1092 return 1; 1093 } 1094 1095 *addr = info->reset_addr; 1096 1097 return 0; 1098 } 1099 1100 static int 1101 sev_es_find_reset_vector(void *flash_ptr, uint64_t flash_size, 1102 uint32_t *addr) 1103 { 1104 QemuUUID info_guid, *guid; 1105 SevInfoBlock *info; 1106 uint8_t *data; 1107 uint16_t *len; 1108 1109 /* 1110 * Initialize the address to zero. An address of zero with a successful 1111 * return code indicates that SEV-ES is not active. 1112 */ 1113 *addr = 0; 1114 1115 /* 1116 * Extract the AP reset vector for SEV-ES guests by locating the SEV GUID. 1117 * The SEV GUID is located on its own (original implementation) or within 1118 * the Firmware GUID Table (new implementation), either of which are 1119 * located 32 bytes from the end of the flash. 1120 * 1121 * Check the Firmware GUID Table first. 1122 */ 1123 if (pc_system_ovmf_table_find(SEV_INFO_BLOCK_GUID, &data, NULL)) { 1124 return sev_es_parse_reset_block((SevInfoBlock *)data, addr); 1125 } 1126 1127 /* 1128 * SEV info block not found in the Firmware GUID Table (or there isn't 1129 * a Firmware GUID Table), fall back to the original implementation. 1130 */ 1131 data = flash_ptr + flash_size - 0x20; 1132 1133 qemu_uuid_parse(SEV_INFO_BLOCK_GUID, &info_guid); 1134 info_guid = qemu_uuid_bswap(info_guid); /* GUIDs are LE */ 1135 1136 guid = (QemuUUID *)(data - sizeof(info_guid)); 1137 if (!qemu_uuid_is_equal(guid, &info_guid)) { 1138 error_report("SEV information block/Firmware GUID Table block not found in pflash rom"); 1139 return 1; 1140 } 1141 1142 len = (uint16_t *)((uint8_t *)guid - sizeof(*len)); 1143 info = (SevInfoBlock *)(data - le16_to_cpu(*len)); 1144 1145 return sev_es_parse_reset_block(info, addr); 1146 } 1147 1148 void sev_es_set_reset_vector(CPUState *cpu) 1149 { 1150 X86CPU *x86; 1151 CPUX86State *env; 1152 1153 /* Only update if we have valid reset information */ 1154 if (!sev_guest || !sev_guest->reset_data_valid) { 1155 return; 1156 } 1157 1158 /* Do not update the BSP reset state */ 1159 if (cpu->cpu_index == 0) { 1160 return; 1161 } 1162 1163 x86 = X86_CPU(cpu); 1164 env = &x86->env; 1165 1166 cpu_x86_load_seg_cache(env, R_CS, 0xf000, sev_guest->reset_cs, 0xffff, 1167 DESC_P_MASK | DESC_S_MASK | DESC_CS_MASK | 1168 DESC_R_MASK | DESC_A_MASK); 1169 1170 env->eip = sev_guest->reset_ip; 1171 } 1172 1173 int sev_es_save_reset_vector(void *flash_ptr, uint64_t flash_size) 1174 { 1175 CPUState *cpu; 1176 uint32_t addr; 1177 int ret; 1178 1179 if (!sev_es_enabled()) { 1180 return 0; 1181 } 1182 1183 addr = 0; 1184 ret = sev_es_find_reset_vector(flash_ptr, flash_size, 1185 &addr); 1186 if (ret) { 1187 return ret; 1188 } 1189 1190 if (addr) { 1191 sev_guest->reset_cs = addr & 0xffff0000; 1192 sev_guest->reset_ip = addr & 0x0000ffff; 1193 sev_guest->reset_data_valid = true; 1194 1195 CPU_FOREACH(cpu) { 1196 sev_es_set_reset_vector(cpu); 1197 } 1198 } 1199 1200 return 0; 1201 } 1202 1203 static const QemuUUID sev_hash_table_header_guid = { 1204 .data = UUID_LE(0x9438d606, 0x4f22, 0x4cc9, 0xb4, 0x79, 0xa7, 0x93, 1205 0xd4, 0x11, 0xfd, 0x21) 1206 }; 1207 1208 static const QemuUUID sev_kernel_entry_guid = { 1209 .data = UUID_LE(0x4de79437, 0xabd2, 0x427f, 0xb8, 0x35, 0xd5, 0xb1, 1210 0x72, 0xd2, 0x04, 0x5b) 1211 }; 1212 static const QemuUUID sev_initrd_entry_guid = { 1213 .data = UUID_LE(0x44baf731, 0x3a2f, 0x4bd7, 0x9a, 0xf1, 0x41, 0xe2, 1214 0x91, 0x69, 0x78, 0x1d) 1215 }; 1216 static const QemuUUID sev_cmdline_entry_guid = { 1217 .data = UUID_LE(0x97d02dd8, 0xbd20, 0x4c94, 0xaa, 0x78, 0xe7, 0x71, 1218 0x4d, 0x36, 0xab, 0x2a) 1219 }; 1220 1221 /* 1222 * Add the hashes of the linux kernel/initrd/cmdline to an encrypted guest page 1223 * which is included in SEV's initial memory measurement. 1224 */ 1225 bool sev_add_kernel_loader_hashes(SevKernelLoaderContext *ctx, Error **errp) 1226 { 1227 uint8_t *data; 1228 SevHashTableDescriptor *area; 1229 SevHashTable *ht; 1230 PaddedSevHashTable *padded_ht; 1231 uint8_t cmdline_hash[HASH_SIZE]; 1232 uint8_t initrd_hash[HASH_SIZE]; 1233 uint8_t kernel_hash[HASH_SIZE]; 1234 uint8_t *hashp; 1235 size_t hash_len = HASH_SIZE; 1236 hwaddr mapped_len = sizeof(*padded_ht); 1237 MemTxAttrs attrs = { 0 }; 1238 bool ret = true; 1239 1240 /* 1241 * Only add the kernel hashes if the sev-guest configuration explicitly 1242 * stated kernel-hashes=on. 1243 */ 1244 if (!sev_guest->kernel_hashes) { 1245 return false; 1246 } 1247 1248 if (!pc_system_ovmf_table_find(SEV_HASH_TABLE_RV_GUID, &data, NULL)) { 1249 error_setg(errp, "SEV: kernel specified but guest firmware " 1250 "has no hashes table GUID"); 1251 return false; 1252 } 1253 area = (SevHashTableDescriptor *)data; 1254 if (!area->base || area->size < sizeof(PaddedSevHashTable)) { 1255 error_setg(errp, "SEV: guest firmware hashes table area is invalid " 1256 "(base=0x%x size=0x%x)", area->base, area->size); 1257 return false; 1258 } 1259 1260 /* 1261 * Calculate hash of kernel command-line with the terminating null byte. If 1262 * the user doesn't supply a command-line via -append, the 1-byte "\0" will 1263 * be used. 1264 */ 1265 hashp = cmdline_hash; 1266 if (qcrypto_hash_bytes(QCRYPTO_HASH_ALG_SHA256, ctx->cmdline_data, 1267 ctx->cmdline_size, &hashp, &hash_len, errp) < 0) { 1268 return false; 1269 } 1270 assert(hash_len == HASH_SIZE); 1271 1272 /* 1273 * Calculate hash of initrd. If the user doesn't supply an initrd via 1274 * -initrd, an empty buffer will be used (ctx->initrd_size == 0). 1275 */ 1276 hashp = initrd_hash; 1277 if (qcrypto_hash_bytes(QCRYPTO_HASH_ALG_SHA256, ctx->initrd_data, 1278 ctx->initrd_size, &hashp, &hash_len, errp) < 0) { 1279 return false; 1280 } 1281 assert(hash_len == HASH_SIZE); 1282 1283 /* Calculate hash of the kernel */ 1284 hashp = kernel_hash; 1285 struct iovec iov[2] = { 1286 { .iov_base = ctx->setup_data, .iov_len = ctx->setup_size }, 1287 { .iov_base = ctx->kernel_data, .iov_len = ctx->kernel_size } 1288 }; 1289 if (qcrypto_hash_bytesv(QCRYPTO_HASH_ALG_SHA256, iov, ARRAY_SIZE(iov), 1290 &hashp, &hash_len, errp) < 0) { 1291 return false; 1292 } 1293 assert(hash_len == HASH_SIZE); 1294 1295 /* 1296 * Populate the hashes table in the guest's memory at the OVMF-designated 1297 * area for the SEV hashes table 1298 */ 1299 padded_ht = address_space_map(&address_space_memory, area->base, 1300 &mapped_len, true, attrs); 1301 if (!padded_ht || mapped_len != sizeof(*padded_ht)) { 1302 error_setg(errp, "SEV: cannot map hashes table guest memory area"); 1303 return false; 1304 } 1305 ht = &padded_ht->ht; 1306 1307 ht->guid = sev_hash_table_header_guid; 1308 ht->len = sizeof(*ht); 1309 1310 ht->cmdline.guid = sev_cmdline_entry_guid; 1311 ht->cmdline.len = sizeof(ht->cmdline); 1312 memcpy(ht->cmdline.hash, cmdline_hash, sizeof(ht->cmdline.hash)); 1313 1314 ht->initrd.guid = sev_initrd_entry_guid; 1315 ht->initrd.len = sizeof(ht->initrd); 1316 memcpy(ht->initrd.hash, initrd_hash, sizeof(ht->initrd.hash)); 1317 1318 ht->kernel.guid = sev_kernel_entry_guid; 1319 ht->kernel.len = sizeof(ht->kernel); 1320 memcpy(ht->kernel.hash, kernel_hash, sizeof(ht->kernel.hash)); 1321 1322 /* zero the excess data so the measurement can be reliably calculated */ 1323 memset(padded_ht->padding, 0, sizeof(padded_ht->padding)); 1324 1325 if (sev_encrypt_flash((uint8_t *)padded_ht, sizeof(*padded_ht), errp) < 0) { 1326 ret = false; 1327 } 1328 1329 address_space_unmap(&address_space_memory, padded_ht, 1330 mapped_len, true, mapped_len); 1331 1332 return ret; 1333 } 1334 1335 static void 1336 sev_register_types(void) 1337 { 1338 type_register_static(&sev_guest_info); 1339 } 1340 1341 type_init(sev_register_types); 1342