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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 int sev_get_cpu0_id(int fd, guchar **id, size_t *id_len, Error **errp)
535 {
536 guchar *id_data;
537 struct sev_user_data_get_id2 get_id2 = {};
538 int err, r;
539
540 /* query the ID length */
541 r = sev_platform_ioctl(fd, SEV_GET_ID2, &get_id2, &err);
542 if (r < 0 && err != SEV_RET_INVALID_LEN) {
543 error_setg(errp, "SEV: Failed to get ID ret=%d fw_err=%d (%s)",
544 r, err, fw_error_to_str(err));
545 return 1;
546 }
547
548 id_data = g_new(guchar, get_id2.length);
549 get_id2.address = (unsigned long)id_data;
550
551 r = sev_platform_ioctl(fd, SEV_GET_ID2, &get_id2, &err);
552 if (r < 0) {
553 error_setg(errp, "SEV: Failed to get ID ret=%d fw_err=%d (%s)",
554 r, err, fw_error_to_str(err));
555 goto err;
556 }
557
558 *id = id_data;
559 *id_len = get_id2.length;
560 return 0;
561
562 err:
563 g_free(id_data);
564 return 1;
565 }
566
567 static SevCapability *sev_get_capabilities(Error **errp)
568 {
569 SevCapability *cap = NULL;
570 guchar *pdh_data = NULL;
571 guchar *cert_chain_data = NULL;
572 guchar *cpu0_id_data = NULL;
573 size_t pdh_len = 0, cert_chain_len = 0, cpu0_id_len = 0;
574 uint32_t ebx;
575 int fd;
576
577 if (!kvm_enabled()) {
578 error_setg(errp, "KVM not enabled");
579 return NULL;
580 }
581 if (kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_OP, NULL) < 0) {
582 error_setg(errp, "SEV is not enabled in KVM");
583 return NULL;
584 }
585
586 fd = open(DEFAULT_SEV_DEVICE, O_RDWR);
587 if (fd < 0) {
588 error_setg_errno(errp, errno, "SEV: Failed to open %s",
589 DEFAULT_SEV_DEVICE);
590 return NULL;
591 }
592
593 if (sev_get_pdh_info(fd, &pdh_data, &pdh_len,
594 &cert_chain_data, &cert_chain_len, errp)) {
595 goto out;
596 }
597
598 if (sev_get_cpu0_id(fd, &cpu0_id_data, &cpu0_id_len, errp)) {
599 goto out;
600 }
601
602 cap = g_new0(SevCapability, 1);
603 cap->pdh = g_base64_encode(pdh_data, pdh_len);
604 cap->cert_chain = g_base64_encode(cert_chain_data, cert_chain_len);
605 cap->cpu0_id = g_base64_encode(cpu0_id_data, cpu0_id_len);
606
607 host_cpuid(0x8000001F, 0, NULL, &ebx, NULL, NULL);
608 cap->cbitpos = ebx & 0x3f;
609
610 /*
611 * When SEV feature is enabled, we loose one bit in guest physical
612 * addressing.
613 */
614 cap->reduced_phys_bits = 1;
615
616 out:
617 g_free(cpu0_id_data);
618 g_free(pdh_data);
619 g_free(cert_chain_data);
620 close(fd);
621 return cap;
622 }
623
624 SevCapability *qmp_query_sev_capabilities(Error **errp)
625 {
626 return sev_get_capabilities(errp);
627 }
628
629 static SevAttestationReport *sev_get_attestation_report(const char *mnonce,
630 Error **errp)
631 {
632 struct kvm_sev_attestation_report input = {};
633 SevAttestationReport *report = NULL;
634 SevGuestState *sev = sev_guest;
635 g_autofree guchar *data = NULL;
636 g_autofree guchar *buf = NULL;
637 gsize len;
638 int err = 0, ret;
639
640 if (!sev_enabled()) {
641 error_setg(errp, "SEV is not enabled");
642 return NULL;
643 }
644
645 /* lets decode the mnonce string */
646 buf = g_base64_decode(mnonce, &len);
647 if (!buf) {
648 error_setg(errp, "SEV: failed to decode mnonce input");
649 return NULL;
650 }
651
652 /* verify the input mnonce length */
653 if (len != sizeof(input.mnonce)) {
654 error_setg(errp, "SEV: mnonce must be %zu bytes (got %" G_GSIZE_FORMAT ")",
655 sizeof(input.mnonce), len);
656 return NULL;
657 }
658
659 /* Query the report length */
660 ret = sev_ioctl(sev->sev_fd, KVM_SEV_GET_ATTESTATION_REPORT,
661 &input, &err);
662 if (ret < 0) {
663 if (err != SEV_RET_INVALID_LEN) {
664 error_setg(errp, "SEV: Failed to query the attestation report"
665 " length ret=%d fw_err=%d (%s)",
666 ret, err, fw_error_to_str(err));
667 return NULL;
668 }
669 }
670
671 data = g_malloc(input.len);
672 input.uaddr = (unsigned long)data;
673 memcpy(input.mnonce, buf, sizeof(input.mnonce));
674
675 /* Query the report */
676 ret = sev_ioctl(sev->sev_fd, KVM_SEV_GET_ATTESTATION_REPORT,
677 &input, &err);
678 if (ret) {
679 error_setg_errno(errp, errno, "SEV: Failed to get attestation report"
680 " ret=%d fw_err=%d (%s)", ret, err, fw_error_to_str(err));
681 return NULL;
682 }
683
684 report = g_new0(SevAttestationReport, 1);
685 report->data = g_base64_encode(data, input.len);
686
687 trace_kvm_sev_attestation_report(mnonce, report->data);
688
689 return report;
690 }
691
692 SevAttestationReport *qmp_query_sev_attestation_report(const char *mnonce,
693 Error **errp)
694 {
695 return sev_get_attestation_report(mnonce, errp);
696 }
697
698 static int
699 sev_read_file_base64(const char *filename, guchar **data, gsize *len)
700 {
701 gsize sz;
702 g_autofree gchar *base64 = NULL;
703 GError *error = NULL;
704
705 if (!g_file_get_contents(filename, &base64, &sz, &error)) {
706 error_report("SEV: Failed to read '%s' (%s)", filename, error->message);
707 g_error_free(error);
708 return -1;
709 }
710
711 *data = g_base64_decode(base64, len);
712 return 0;
713 }
714
715 static int
716 sev_launch_start(SevGuestState *sev)
717 {
718 gsize sz;
719 int ret = 1;
720 int fw_error, rc;
721 struct kvm_sev_launch_start start = {
722 .handle = sev->handle, .policy = sev->policy
723 };
724 guchar *session = NULL, *dh_cert = NULL;
725
726 if (sev->session_file) {
727 if (sev_read_file_base64(sev->session_file, &session, &sz) < 0) {
728 goto out;
729 }
730 start.session_uaddr = (unsigned long)session;
731 start.session_len = sz;
732 }
733
734 if (sev->dh_cert_file) {
735 if (sev_read_file_base64(sev->dh_cert_file, &dh_cert, &sz) < 0) {
736 goto out;
737 }
738 start.dh_uaddr = (unsigned long)dh_cert;
739 start.dh_len = sz;
740 }
741
742 trace_kvm_sev_launch_start(start.policy, session, dh_cert);
743 rc = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_START, &start, &fw_error);
744 if (rc < 0) {
745 error_report("%s: LAUNCH_START ret=%d fw_error=%d '%s'",
746 __func__, ret, fw_error, fw_error_to_str(fw_error));
747 goto out;
748 }
749
750 sev_set_guest_state(sev, SEV_STATE_LAUNCH_UPDATE);
751 sev->handle = start.handle;
752 ret = 0;
753
754 out:
755 g_free(session);
756 g_free(dh_cert);
757 return ret;
758 }
759
760 static int
761 sev_launch_update_data(SevGuestState *sev, uint8_t *addr, uint64_t len)
762 {
763 int ret, fw_error;
764 struct kvm_sev_launch_update_data update;
765
766 if (!addr || !len) {
767 return 1;
768 }
769
770 update.uaddr = (__u64)(unsigned long)addr;
771 update.len = len;
772 trace_kvm_sev_launch_update_data(addr, len);
773 ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_UPDATE_DATA,
774 &update, &fw_error);
775 if (ret) {
776 error_report("%s: LAUNCH_UPDATE ret=%d fw_error=%d '%s'",
777 __func__, ret, fw_error, fw_error_to_str(fw_error));
778 }
779
780 return ret;
781 }
782
783 static int
784 sev_launch_update_vmsa(SevGuestState *sev)
785 {
786 int ret, fw_error;
787
788 ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_UPDATE_VMSA, NULL, &fw_error);
789 if (ret) {
790 error_report("%s: LAUNCH_UPDATE_VMSA ret=%d fw_error=%d '%s'",
791 __func__, ret, fw_error, fw_error_to_str(fw_error));
792 }
793
794 return ret;
795 }
796
797 static void
798 sev_launch_get_measure(Notifier *notifier, void *unused)
799 {
800 SevGuestState *sev = sev_guest;
801 int ret, error;
802 g_autofree guchar *data = NULL;
803 struct kvm_sev_launch_measure measurement = {};
804
805 if (!sev_check_state(sev, SEV_STATE_LAUNCH_UPDATE)) {
806 return;
807 }
808
809 if (sev_es_enabled()) {
810 /* measure all the VM save areas before getting launch_measure */
811 ret = sev_launch_update_vmsa(sev);
812 if (ret) {
813 exit(1);
814 }
815 }
816
817 /* query the measurement blob length */
818 ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_MEASURE,
819 &measurement, &error);
820 if (!measurement.len) {
821 error_report("%s: LAUNCH_MEASURE ret=%d fw_error=%d '%s'",
822 __func__, ret, error, fw_error_to_str(errno));
823 return;
824 }
825
826 data = g_new0(guchar, measurement.len);
827 measurement.uaddr = (unsigned long)data;
828
829 /* get the measurement blob */
830 ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_MEASURE,
831 &measurement, &error);
832 if (ret) {
833 error_report("%s: LAUNCH_MEASURE ret=%d fw_error=%d '%s'",
834 __func__, ret, error, fw_error_to_str(errno));
835 return;
836 }
837
838 sev_set_guest_state(sev, SEV_STATE_LAUNCH_SECRET);
839
840 /* encode the measurement value and emit the event */
841 sev->measurement = g_base64_encode(data, measurement.len);
842 trace_kvm_sev_launch_measurement(sev->measurement);
843 }
844
845 static char *sev_get_launch_measurement(void)
846 {
847 if (sev_guest &&
848 sev_guest->state >= SEV_STATE_LAUNCH_SECRET) {
849 return g_strdup(sev_guest->measurement);
850 }
851
852 return NULL;
853 }
854
855 SevLaunchMeasureInfo *qmp_query_sev_launch_measure(Error **errp)
856 {
857 char *data;
858 SevLaunchMeasureInfo *info;
859
860 data = sev_get_launch_measurement();
861 if (!data) {
862 error_setg(errp, "SEV launch measurement is not available");
863 return NULL;
864 }
865
866 info = g_malloc0(sizeof(*info));
867 info->data = data;
868
869 return info;
870 }
871
872 static Notifier sev_machine_done_notify = {
873 .notify = sev_launch_get_measure,
874 };
875
876 static void
877 sev_launch_finish(SevGuestState *sev)
878 {
879 int ret, error;
880
881 trace_kvm_sev_launch_finish();
882 ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_FINISH, 0, &error);
883 if (ret) {
884 error_report("%s: LAUNCH_FINISH ret=%d fw_error=%d '%s'",
885 __func__, ret, error, fw_error_to_str(error));
886 exit(1);
887 }
888
889 sev_set_guest_state(sev, SEV_STATE_RUNNING);
890
891 /* add migration blocker */
892 error_setg(&sev_mig_blocker,
893 "SEV: Migration is not implemented");
894 migrate_add_blocker(sev_mig_blocker, &error_fatal);
895 }
896
897 static void
898 sev_vm_state_change(void *opaque, bool running, RunState state)
899 {
900 SevGuestState *sev = opaque;
901
902 if (running) {
903 if (!sev_check_state(sev, SEV_STATE_RUNNING)) {
904 sev_launch_finish(sev);
905 }
906 }
907 }
908
909 int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
910 {
911 SevGuestState *sev
912 = (SevGuestState *)object_dynamic_cast(OBJECT(cgs), TYPE_SEV_GUEST);
913 char *devname;
914 int ret, fw_error, cmd;
915 uint32_t ebx;
916 uint32_t host_cbitpos;
917 struct sev_user_data_status status = {};
918
919 if (!sev) {
920 return 0;
921 }
922
923 ret = ram_block_discard_disable(true);
924 if (ret) {
925 error_report("%s: cannot disable RAM discard", __func__);
926 return -1;
927 }
928
929 sev_guest = sev;
930 sev->state = SEV_STATE_UNINIT;
931
932 host_cpuid(0x8000001F, 0, NULL, &ebx, NULL, NULL);
933 host_cbitpos = ebx & 0x3f;
934
935 if (host_cbitpos != sev->cbitpos) {
936 error_setg(errp, "%s: cbitpos check failed, host '%d' requested '%d'",
937 __func__, host_cbitpos, sev->cbitpos);
938 goto err;
939 }
940
941 if (sev->reduced_phys_bits < 1) {
942 error_setg(errp, "%s: reduced_phys_bits check failed, it should be >=1,"
943 " requested '%d'", __func__, sev->reduced_phys_bits);
944 goto err;
945 }
946
947 devname = object_property_get_str(OBJECT(sev), "sev-device", NULL);
948 sev->sev_fd = open(devname, O_RDWR);
949 if (sev->sev_fd < 0) {
950 error_setg(errp, "%s: Failed to open %s '%s'", __func__,
951 devname, strerror(errno));
952 g_free(devname);
953 goto err;
954 }
955 g_free(devname);
956
957 ret = sev_platform_ioctl(sev->sev_fd, SEV_PLATFORM_STATUS, &status,
958 &fw_error);
959 if (ret) {
960 error_setg(errp, "%s: failed to get platform status ret=%d "
961 "fw_error='%d: %s'", __func__, ret, fw_error,
962 fw_error_to_str(fw_error));
963 goto err;
964 }
965 sev->build_id = status.build;
966 sev->api_major = status.api_major;
967 sev->api_minor = status.api_minor;
968
969 if (sev_es_enabled()) {
970 if (!kvm_kernel_irqchip_allowed()) {
971 error_report("%s: SEV-ES guests require in-kernel irqchip support",
972 __func__);
973 goto err;
974 }
975
976 if (!(status.flags & SEV_STATUS_FLAGS_CONFIG_ES)) {
977 error_report("%s: guest policy requires SEV-ES, but "
978 "host SEV-ES support unavailable",
979 __func__);
980 goto err;
981 }
982 cmd = KVM_SEV_ES_INIT;
983 } else {
984 cmd = KVM_SEV_INIT;
985 }
986
987 trace_kvm_sev_init();
988 ret = sev_ioctl(sev->sev_fd, cmd, NULL, &fw_error);
989 if (ret) {
990 error_setg(errp, "%s: failed to initialize ret=%d fw_error=%d '%s'",
991 __func__, ret, fw_error, fw_error_to_str(fw_error));
992 goto err;
993 }
994
995 ret = sev_launch_start(sev);
996 if (ret) {
997 error_setg(errp, "%s: failed to create encryption context", __func__);
998 goto err;
999 }
1000
1001 ram_block_notifier_add(&sev_ram_notifier);
1002 qemu_add_machine_init_done_notifier(&sev_machine_done_notify);
1003 qemu_add_vm_change_state_handler(sev_vm_state_change, sev);
1004
1005 cgs->ready = true;
1006
1007 return 0;
1008 err:
1009 sev_guest = NULL;
1010 ram_block_discard_disable(false);
1011 return -1;
1012 }
1013
1014 int
1015 sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp)
1016 {
1017 if (!sev_guest) {
1018 return 0;
1019 }
1020
1021 /* if SEV is in update state then encrypt the data else do nothing */
1022 if (sev_check_state(sev_guest, SEV_STATE_LAUNCH_UPDATE)) {
1023 int ret = sev_launch_update_data(sev_guest, ptr, len);
1024 if (ret < 0) {
1025 error_setg(errp, "SEV: Failed to encrypt pflash rom");
1026 return ret;
1027 }
1028 }
1029
1030 return 0;
1031 }
1032
1033 int sev_inject_launch_secret(const char *packet_hdr, const char *secret,
1034 uint64_t gpa, Error **errp)
1035 {
1036 struct kvm_sev_launch_secret input;
1037 g_autofree guchar *data = NULL, *hdr = NULL;
1038 int error, ret = 1;
1039 void *hva;
1040 gsize hdr_sz = 0, data_sz = 0;
1041 MemoryRegion *mr = NULL;
1042
1043 if (!sev_guest) {
1044 error_setg(errp, "SEV not enabled for guest");
1045 return 1;
1046 }
1047
1048 /* secret can be injected only in this state */
1049 if (!sev_check_state(sev_guest, SEV_STATE_LAUNCH_SECRET)) {
1050 error_setg(errp, "SEV: Not in correct state. (LSECRET) %x",
1051 sev_guest->state);
1052 return 1;
1053 }
1054
1055 hdr = g_base64_decode(packet_hdr, &hdr_sz);
1056 if (!hdr || !hdr_sz) {
1057 error_setg(errp, "SEV: Failed to decode sequence header");
1058 return 1;
1059 }
1060
1061 data = g_base64_decode(secret, &data_sz);
1062 if (!data || !data_sz) {
1063 error_setg(errp, "SEV: Failed to decode data");
1064 return 1;
1065 }
1066
1067 hva = gpa2hva(&mr, gpa, data_sz, errp);
1068 if (!hva) {
1069 error_prepend(errp, "SEV: Failed to calculate guest address: ");
1070 return 1;
1071 }
1072
1073 input.hdr_uaddr = (uint64_t)(unsigned long)hdr;
1074 input.hdr_len = hdr_sz;
1075
1076 input.trans_uaddr = (uint64_t)(unsigned long)data;
1077 input.trans_len = data_sz;
1078
1079 input.guest_uaddr = (uint64_t)(unsigned long)hva;
1080 input.guest_len = data_sz;
1081
1082 trace_kvm_sev_launch_secret(gpa, input.guest_uaddr,
1083 input.trans_uaddr, input.trans_len);
1084
1085 ret = sev_ioctl(sev_guest->sev_fd, KVM_SEV_LAUNCH_SECRET,
1086 &input, &error);
1087 if (ret) {
1088 error_setg(errp, "SEV: failed to inject secret ret=%d fw_error=%d '%s'",
1089 ret, error, fw_error_to_str(error));
1090 return ret;
1091 }
1092
1093 return 0;
1094 }
1095
1096 #define SEV_SECRET_GUID "4c2eb361-7d9b-4cc3-8081-127c90d3d294"
1097 struct sev_secret_area {
1098 uint32_t base;
1099 uint32_t size;
1100 };
1101
1102 void qmp_sev_inject_launch_secret(const char *packet_hdr,
1103 const char *secret,
1104 bool has_gpa, uint64_t gpa,
1105 Error **errp)
1106 {
1107 if (!sev_enabled()) {
1108 error_setg(errp, "SEV not enabled for guest");
1109 return;
1110 }
1111 if (!has_gpa) {
1112 uint8_t *data;
1113 struct sev_secret_area *area;
1114
1115 if (!pc_system_ovmf_table_find(SEV_SECRET_GUID, &data, NULL)) {
1116 error_setg(errp, "SEV: no secret area found in OVMF,"
1117 " gpa must be specified.");
1118 return;
1119 }
1120 area = (struct sev_secret_area *)data;
1121 gpa = area->base;
1122 }
1123
1124 sev_inject_launch_secret(packet_hdr, secret, gpa, errp);
1125 }
1126
1127 static int
1128 sev_es_parse_reset_block(SevInfoBlock *info, uint32_t *addr)
1129 {
1130 if (!info->reset_addr) {
1131 error_report("SEV-ES reset address is zero");
1132 return 1;
1133 }
1134
1135 *addr = info->reset_addr;
1136
1137 return 0;
1138 }
1139
1140 static int
1141 sev_es_find_reset_vector(void *flash_ptr, uint64_t flash_size,
1142 uint32_t *addr)
1143 {
1144 QemuUUID info_guid, *guid;
1145 SevInfoBlock *info;
1146 uint8_t *data;
1147 uint16_t *len;
1148
1149 /*
1150 * Initialize the address to zero. An address of zero with a successful
1151 * return code indicates that SEV-ES is not active.
1152 */
1153 *addr = 0;
1154
1155 /*
1156 * Extract the AP reset vector for SEV-ES guests by locating the SEV GUID.
1157 * The SEV GUID is located on its own (original implementation) or within
1158 * the Firmware GUID Table (new implementation), either of which are
1159 * located 32 bytes from the end of the flash.
1160 *
1161 * Check the Firmware GUID Table first.
1162 */
1163 if (pc_system_ovmf_table_find(SEV_INFO_BLOCK_GUID, &data, NULL)) {
1164 return sev_es_parse_reset_block((SevInfoBlock *)data, addr);
1165 }
1166
1167 /*
1168 * SEV info block not found in the Firmware GUID Table (or there isn't
1169 * a Firmware GUID Table), fall back to the original implementation.
1170 */
1171 data = flash_ptr + flash_size - 0x20;
1172
1173 qemu_uuid_parse(SEV_INFO_BLOCK_GUID, &info_guid);
1174 info_guid = qemu_uuid_bswap(info_guid); /* GUIDs are LE */
1175
1176 guid = (QemuUUID *)(data - sizeof(info_guid));
1177 if (!qemu_uuid_is_equal(guid, &info_guid)) {
1178 error_report("SEV information block/Firmware GUID Table block not found in pflash rom");
1179 return 1;
1180 }
1181
1182 len = (uint16_t *)((uint8_t *)guid - sizeof(*len));
1183 info = (SevInfoBlock *)(data - le16_to_cpu(*len));
1184
1185 return sev_es_parse_reset_block(info, addr);
1186 }
1187
1188 void sev_es_set_reset_vector(CPUState *cpu)
1189 {
1190 X86CPU *x86;
1191 CPUX86State *env;
1192
1193 /* Only update if we have valid reset information */
1194 if (!sev_guest || !sev_guest->reset_data_valid) {
1195 return;
1196 }
1197
1198 /* Do not update the BSP reset state */
1199 if (cpu->cpu_index == 0) {
1200 return;
1201 }
1202
1203 x86 = X86_CPU(cpu);
1204 env = &x86->env;
1205
1206 cpu_x86_load_seg_cache(env, R_CS, 0xf000, sev_guest->reset_cs, 0xffff,
1207 DESC_P_MASK | DESC_S_MASK | DESC_CS_MASK |
1208 DESC_R_MASK | DESC_A_MASK);
1209
1210 env->eip = sev_guest->reset_ip;
1211 }
1212
1213 int sev_es_save_reset_vector(void *flash_ptr, uint64_t flash_size)
1214 {
1215 CPUState *cpu;
1216 uint32_t addr;
1217 int ret;
1218
1219 if (!sev_es_enabled()) {
1220 return 0;
1221 }
1222
1223 addr = 0;
1224 ret = sev_es_find_reset_vector(flash_ptr, flash_size,
1225 &addr);
1226 if (ret) {
1227 return ret;
1228 }
1229
1230 if (addr) {
1231 sev_guest->reset_cs = addr & 0xffff0000;
1232 sev_guest->reset_ip = addr & 0x0000ffff;
1233 sev_guest->reset_data_valid = true;
1234
1235 CPU_FOREACH(cpu) {
1236 sev_es_set_reset_vector(cpu);
1237 }
1238 }
1239
1240 return 0;
1241 }
1242
1243 static const QemuUUID sev_hash_table_header_guid = {
1244 .data = UUID_LE(0x9438d606, 0x4f22, 0x4cc9, 0xb4, 0x79, 0xa7, 0x93,
1245 0xd4, 0x11, 0xfd, 0x21)
1246 };
1247
1248 static const QemuUUID sev_kernel_entry_guid = {
1249 .data = UUID_LE(0x4de79437, 0xabd2, 0x427f, 0xb8, 0x35, 0xd5, 0xb1,
1250 0x72, 0xd2, 0x04, 0x5b)
1251 };
1252 static const QemuUUID sev_initrd_entry_guid = {
1253 .data = UUID_LE(0x44baf731, 0x3a2f, 0x4bd7, 0x9a, 0xf1, 0x41, 0xe2,
1254 0x91, 0x69, 0x78, 0x1d)
1255 };
1256 static const QemuUUID sev_cmdline_entry_guid = {
1257 .data = UUID_LE(0x97d02dd8, 0xbd20, 0x4c94, 0xaa, 0x78, 0xe7, 0x71,
1258 0x4d, 0x36, 0xab, 0x2a)
1259 };
1260
1261 /*
1262 * Add the hashes of the linux kernel/initrd/cmdline to an encrypted guest page
1263 * which is included in SEV's initial memory measurement.
1264 */
1265 bool sev_add_kernel_loader_hashes(SevKernelLoaderContext *ctx, Error **errp)
1266 {
1267 uint8_t *data;
1268 SevHashTableDescriptor *area;
1269 SevHashTable *ht;
1270 PaddedSevHashTable *padded_ht;
1271 uint8_t cmdline_hash[HASH_SIZE];
1272 uint8_t initrd_hash[HASH_SIZE];
1273 uint8_t kernel_hash[HASH_SIZE];
1274 uint8_t *hashp;
1275 size_t hash_len = HASH_SIZE;
1276 hwaddr mapped_len = sizeof(*padded_ht);
1277 MemTxAttrs attrs = { 0 };
1278 bool ret = true;
1279
1280 /*
1281 * Only add the kernel hashes if the sev-guest configuration explicitly
1282 * stated kernel-hashes=on.
1283 */
1284 if (!sev_guest->kernel_hashes) {
1285 return false;
1286 }
1287
1288 if (!pc_system_ovmf_table_find(SEV_HASH_TABLE_RV_GUID, &data, NULL)) {
1289 error_setg(errp, "SEV: kernel specified but guest firmware "
1290 "has no hashes table GUID");
1291 return false;
1292 }
1293 area = (SevHashTableDescriptor *)data;
1294 if (!area->base || area->size < sizeof(PaddedSevHashTable)) {
1295 error_setg(errp, "SEV: guest firmware hashes table area is invalid "
1296 "(base=0x%x size=0x%x)", area->base, area->size);
1297 return false;
1298 }
1299
1300 /*
1301 * Calculate hash of kernel command-line with the terminating null byte. If
1302 * the user doesn't supply a command-line via -append, the 1-byte "\0" will
1303 * be used.
1304 */
1305 hashp = cmdline_hash;
1306 if (qcrypto_hash_bytes(QCRYPTO_HASH_ALG_SHA256, ctx->cmdline_data,
1307 ctx->cmdline_size, &hashp, &hash_len, errp) < 0) {
1308 return false;
1309 }
1310 assert(hash_len == HASH_SIZE);
1311
1312 /*
1313 * Calculate hash of initrd. If the user doesn't supply an initrd via
1314 * -initrd, an empty buffer will be used (ctx->initrd_size == 0).
1315 */
1316 hashp = initrd_hash;
1317 if (qcrypto_hash_bytes(QCRYPTO_HASH_ALG_SHA256, ctx->initrd_data,
1318 ctx->initrd_size, &hashp, &hash_len, errp) < 0) {
1319 return false;
1320 }
1321 assert(hash_len == HASH_SIZE);
1322
1323 /* Calculate hash of the kernel */
1324 hashp = kernel_hash;
1325 struct iovec iov[2] = {
1326 { .iov_base = ctx->setup_data, .iov_len = ctx->setup_size },
1327 { .iov_base = ctx->kernel_data, .iov_len = ctx->kernel_size }
1328 };
1329 if (qcrypto_hash_bytesv(QCRYPTO_HASH_ALG_SHA256, iov, ARRAY_SIZE(iov),
1330 &hashp, &hash_len, errp) < 0) {
1331 return false;
1332 }
1333 assert(hash_len == HASH_SIZE);
1334
1335 /*
1336 * Populate the hashes table in the guest's memory at the OVMF-designated
1337 * area for the SEV hashes table
1338 */
1339 padded_ht = address_space_map(&address_space_memory, area->base,
1340 &mapped_len, true, attrs);
1341 if (!padded_ht || mapped_len != sizeof(*padded_ht)) {
1342 error_setg(errp, "SEV: cannot map hashes table guest memory area");
1343 return false;
1344 }
1345 ht = &padded_ht->ht;
1346
1347 ht->guid = sev_hash_table_header_guid;
1348 ht->len = sizeof(*ht);
1349
1350 ht->cmdline.guid = sev_cmdline_entry_guid;
1351 ht->cmdline.len = sizeof(ht->cmdline);
1352 memcpy(ht->cmdline.hash, cmdline_hash, sizeof(ht->cmdline.hash));
1353
1354 ht->initrd.guid = sev_initrd_entry_guid;
1355 ht->initrd.len = sizeof(ht->initrd);
1356 memcpy(ht->initrd.hash, initrd_hash, sizeof(ht->initrd.hash));
1357
1358 ht->kernel.guid = sev_kernel_entry_guid;
1359 ht->kernel.len = sizeof(ht->kernel);
1360 memcpy(ht->kernel.hash, kernel_hash, sizeof(ht->kernel.hash));
1361
1362 /* zero the excess data so the measurement can be reliably calculated */
1363 memset(padded_ht->padding, 0, sizeof(padded_ht->padding));
1364
1365 if (sev_encrypt_flash((uint8_t *)padded_ht, sizeof(*padded_ht), errp) < 0) {
1366 ret = false;
1367 }
1368
1369 address_space_unmap(&address_space_memory, padded_ht,
1370 mapped_len, true, mapped_len);
1371
1372 return ret;
1373 }
1374
1375 static void
1376 sev_register_types(void)
1377 {
1378 type_register_static(&sev_guest_info);
1379 }
1380
1381 type_init(sev_register_types);