xref: /openbmc/qemu/backends/tpm/tpm_emulator.c (revision 259ebed4)
1 /*
2  *  Emulator TPM driver
3  *
4  *  Copyright (c) 2017 Intel Corporation
5  *  Author: Amarnath Valluri <amarnath.valluri@intel.com>
6  *
7  *  Copyright (c) 2010 - 2013, 2018 IBM Corporation
8  *  Authors:
9  *    Stefan Berger <stefanb@us.ibm.com>
10  *
11  *  Copyright (C) 2011 IAIK, Graz University of Technology
12  *    Author: Andreas Niederl
13  *
14  * This library is free software; you can redistribute it and/or
15  * modify it under the terms of the GNU Lesser General Public
16  * License as published by the Free Software Foundation; either
17  * version 2.1 of the License, or (at your option) any later version.
18  *
19  * This library is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22  * Lesser General Public License for more details.
23  *
24  * You should have received a copy of the GNU Lesser General Public
25  * License along with this library; if not, see <http://www.gnu.org/licenses/>
26  *
27  */
28 
29 #include "qemu/osdep.h"
30 #include "qemu/error-report.h"
31 #include "qemu/module.h"
32 #include "qemu/sockets.h"
33 #include "qemu/lockable.h"
34 #include "io/channel-socket.h"
35 #include "sysemu/runstate.h"
36 #include "sysemu/tpm_backend.h"
37 #include "sysemu/tpm_util.h"
38 #include "tpm_int.h"
39 #include "tpm_ioctl.h"
40 #include "migration/blocker.h"
41 #include "migration/vmstate.h"
42 #include "qapi/error.h"
43 #include "qapi/clone-visitor.h"
44 #include "qapi/qapi-visit-tpm.h"
45 #include "chardev/char-fe.h"
46 #include "trace.h"
47 #include "qom/object.h"
48 
49 #define TYPE_TPM_EMULATOR "tpm-emulator"
50 OBJECT_DECLARE_SIMPLE_TYPE(TPMEmulator, TPM_EMULATOR)
51 
52 #define TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(S, cap) (((S)->caps & (cap)) == (cap))
53 
54 /* data structures */
55 
56 /* blobs from the TPM; part of VM state when migrating */
57 typedef struct TPMBlobBuffers {
58     uint32_t permanent_flags;
59     TPMSizedBuffer permanent;
60 
61     uint32_t volatil_flags;
62     TPMSizedBuffer volatil;
63 
64     uint32_t savestate_flags;
65     TPMSizedBuffer savestate;
66 } TPMBlobBuffers;
67 
68 struct TPMEmulator {
69     TPMBackend parent;
70 
71     TPMEmulatorOptions *options;
72     CharBackend ctrl_chr;
73     QIOChannel *data_ioc;
74     TPMVersion tpm_version;
75     ptm_cap caps; /* capabilities of the TPM */
76     uint8_t cur_locty_number; /* last set locality */
77     Error *migration_blocker;
78 
79     QemuMutex mutex;
80 
81     unsigned int established_flag:1;
82     unsigned int established_flag_cached:1;
83 
84     TPMBlobBuffers state_blobs;
85 
86     bool relock_storage;
87     VMChangeStateEntry *vmstate;
88 };
89 
90 struct tpm_error {
91     uint32_t tpm_result;
92     const char *string;
93 };
94 
95 static const struct tpm_error tpm_errors[] = {
96     /* TPM 1.2 error codes */
97     { TPM_BAD_PARAMETER   , "a parameter is bad" },
98     { TPM_FAIL            , "operation failed" },
99     { TPM_KEYNOTFOUND     , "key could not be found" },
100     { TPM_BAD_PARAM_SIZE  , "bad parameter size"},
101     { TPM_ENCRYPT_ERROR   , "encryption error" },
102     { TPM_DECRYPT_ERROR   , "decryption error" },
103     { TPM_BAD_KEY_PROPERTY, "bad key property" },
104     { TPM_BAD_MODE        , "bad (encryption) mode" },
105     { TPM_BAD_VERSION     , "bad version identifier" },
106     { TPM_BAD_LOCALITY    , "bad locality" },
107     /* TPM 2 error codes */
108     { TPM_RC_FAILURE     , "operation failed" },
109     { TPM_RC_LOCALITY    , "bad locality"     },
110     { TPM_RC_INSUFFICIENT, "insufficient amount of data" },
111 };
112 
113 static const char *tpm_emulator_strerror(uint32_t tpm_result)
114 {
115     size_t i;
116 
117     for (i = 0; i < ARRAY_SIZE(tpm_errors); i++) {
118         if (tpm_errors[i].tpm_result == tpm_result) {
119             return tpm_errors[i].string;
120         }
121     }
122     return "";
123 }
124 
125 static int tpm_emulator_ctrlcmd(TPMEmulator *tpm, unsigned long cmd, void *msg,
126                                 size_t msg_len_in, size_t msg_len_out)
127 {
128     CharBackend *dev = &tpm->ctrl_chr;
129     uint32_t cmd_no = cpu_to_be32(cmd);
130     ssize_t n = sizeof(uint32_t) + msg_len_in;
131     uint8_t *buf = NULL;
132 
133     WITH_QEMU_LOCK_GUARD(&tpm->mutex) {
134         buf = g_alloca(n);
135         memcpy(buf, &cmd_no, sizeof(cmd_no));
136         memcpy(buf + sizeof(cmd_no), msg, msg_len_in);
137 
138         n = qemu_chr_fe_write_all(dev, buf, n);
139         if (n <= 0) {
140             return -1;
141         }
142 
143         if (msg_len_out != 0) {
144             n = qemu_chr_fe_read_all(dev, msg, msg_len_out);
145             if (n <= 0) {
146                 return -1;
147             }
148         }
149     }
150 
151     return 0;
152 }
153 
154 static int tpm_emulator_unix_tx_bufs(TPMEmulator *tpm_emu,
155                                      const uint8_t *in, uint32_t in_len,
156                                      uint8_t *out, uint32_t out_len,
157                                      bool *selftest_done,
158                                      Error **errp)
159 {
160     ssize_t ret;
161     bool is_selftest = false;
162 
163     if (selftest_done) {
164         *selftest_done = false;
165         is_selftest = tpm_util_is_selftest(in, in_len);
166     }
167 
168     ret = qio_channel_write_all(tpm_emu->data_ioc, (char *)in, in_len, errp);
169     if (ret != 0) {
170         return -1;
171     }
172 
173     ret = qio_channel_read_all(tpm_emu->data_ioc, (char *)out,
174               sizeof(struct tpm_resp_hdr), errp);
175     if (ret != 0) {
176         return -1;
177     }
178 
179     ret = qio_channel_read_all(tpm_emu->data_ioc,
180               (char *)out + sizeof(struct tpm_resp_hdr),
181               tpm_cmd_get_size(out) - sizeof(struct tpm_resp_hdr), errp);
182     if (ret != 0) {
183         return -1;
184     }
185 
186     if (is_selftest) {
187         *selftest_done = tpm_cmd_get_errcode(out) == 0;
188     }
189 
190     return 0;
191 }
192 
193 static int tpm_emulator_set_locality(TPMEmulator *tpm_emu, uint8_t locty_number,
194                                      Error **errp)
195 {
196     ptm_loc loc;
197 
198     if (tpm_emu->cur_locty_number == locty_number) {
199         return 0;
200     }
201 
202     trace_tpm_emulator_set_locality(locty_number);
203 
204     memset(&loc, 0, sizeof(loc));
205     loc.u.req.loc = locty_number;
206     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SET_LOCALITY, &loc,
207                              sizeof(loc), sizeof(loc)) < 0) {
208         error_setg(errp, "tpm-emulator: could not set locality : %s",
209                    strerror(errno));
210         return -1;
211     }
212 
213     loc.u.resp.tpm_result = be32_to_cpu(loc.u.resp.tpm_result);
214     if (loc.u.resp.tpm_result != 0) {
215         error_setg(errp, "tpm-emulator: TPM result for set locality : 0x%x",
216                    loc.u.resp.tpm_result);
217         return -1;
218     }
219 
220     tpm_emu->cur_locty_number = locty_number;
221 
222     return 0;
223 }
224 
225 static void tpm_emulator_handle_request(TPMBackend *tb, TPMBackendCmd *cmd,
226                                         Error **errp)
227 {
228     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
229 
230     trace_tpm_emulator_handle_request();
231 
232     if (tpm_emulator_set_locality(tpm_emu, cmd->locty, errp) < 0 ||
233         tpm_emulator_unix_tx_bufs(tpm_emu, cmd->in, cmd->in_len,
234                                   cmd->out, cmd->out_len,
235                                   &cmd->selftest_done, errp) < 0) {
236         tpm_util_write_fatal_error_response(cmd->out, cmd->out_len);
237     }
238 }
239 
240 static int tpm_emulator_probe_caps(TPMEmulator *tpm_emu)
241 {
242     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_GET_CAPABILITY,
243                              &tpm_emu->caps, 0, sizeof(tpm_emu->caps)) < 0) {
244         error_report("tpm-emulator: probing failed : %s", strerror(errno));
245         return -1;
246     }
247 
248     tpm_emu->caps = be64_to_cpu(tpm_emu->caps);
249 
250     trace_tpm_emulator_probe_caps(tpm_emu->caps);
251 
252     return 0;
253 }
254 
255 static int tpm_emulator_check_caps(TPMEmulator *tpm_emu)
256 {
257     ptm_cap caps = 0;
258     const char *tpm = NULL;
259 
260     /* check for min. required capabilities */
261     switch (tpm_emu->tpm_version) {
262     case TPM_VERSION_1_2:
263         caps = PTM_CAP_INIT | PTM_CAP_SHUTDOWN | PTM_CAP_GET_TPMESTABLISHED |
264                PTM_CAP_SET_LOCALITY | PTM_CAP_SET_DATAFD | PTM_CAP_STOP |
265                PTM_CAP_SET_BUFFERSIZE;
266         tpm = "1.2";
267         break;
268     case TPM_VERSION_2_0:
269         caps = PTM_CAP_INIT | PTM_CAP_SHUTDOWN | PTM_CAP_GET_TPMESTABLISHED |
270                PTM_CAP_SET_LOCALITY | PTM_CAP_RESET_TPMESTABLISHED |
271                PTM_CAP_SET_DATAFD | PTM_CAP_STOP | PTM_CAP_SET_BUFFERSIZE;
272         tpm = "2";
273         break;
274     case TPM_VERSION_UNSPEC:
275         error_report("tpm-emulator: TPM version has not been set");
276         return -1;
277     }
278 
279     if (!TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(tpm_emu, caps)) {
280         error_report("tpm-emulator: TPM does not implement minimum set of "
281                      "required capabilities for TPM %s (0x%x)", tpm, (int)caps);
282         return -1;
283     }
284 
285     return 0;
286 }
287 
288 static int tpm_emulator_stop_tpm(TPMBackend *tb)
289 {
290     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
291     ptm_res res;
292 
293     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_STOP, &res, 0, sizeof(res)) < 0) {
294         error_report("tpm-emulator: Could not stop TPM: %s",
295                      strerror(errno));
296         return -1;
297     }
298 
299     res = be32_to_cpu(res);
300     if (res) {
301         error_report("tpm-emulator: TPM result for CMD_STOP: 0x%x %s", res,
302                      tpm_emulator_strerror(res));
303         return -1;
304     }
305 
306     return 0;
307 }
308 
309 static int tpm_emulator_lock_storage(TPMEmulator *tpm_emu)
310 {
311     ptm_lockstorage pls;
312 
313     if (!TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(tpm_emu, PTM_CAP_LOCK_STORAGE)) {
314         trace_tpm_emulator_lock_storage_cmd_not_supt();
315         return 0;
316     }
317 
318     /* give failing side 300 * 10ms time to release lock */
319     pls.u.req.retries = cpu_to_be32(300);
320     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_LOCK_STORAGE, &pls,
321                              sizeof(pls.u.req), sizeof(pls.u.resp)) < 0) {
322         error_report("tpm-emulator: Could not lock storage within 3 seconds: "
323                      "%s", strerror(errno));
324         return -1;
325     }
326 
327     pls.u.resp.tpm_result = be32_to_cpu(pls.u.resp.tpm_result);
328     if (pls.u.resp.tpm_result != 0) {
329         error_report("tpm-emulator: TPM result for CMD_LOCK_STORAGE: 0x%x %s",
330                      pls.u.resp.tpm_result,
331                      tpm_emulator_strerror(pls.u.resp.tpm_result));
332         return -1;
333     }
334 
335     return 0;
336 }
337 
338 static int tpm_emulator_set_buffer_size(TPMBackend *tb,
339                                         size_t wanted_size,
340                                         size_t *actual_size)
341 {
342     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
343     ptm_setbuffersize psbs;
344 
345     if (tpm_emulator_stop_tpm(tb) < 0) {
346         return -1;
347     }
348 
349     psbs.u.req.buffersize = cpu_to_be32(wanted_size);
350 
351     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SET_BUFFERSIZE, &psbs,
352                              sizeof(psbs.u.req), sizeof(psbs.u.resp)) < 0) {
353         error_report("tpm-emulator: Could not set buffer size: %s",
354                      strerror(errno));
355         return -1;
356     }
357 
358     psbs.u.resp.tpm_result = be32_to_cpu(psbs.u.resp.tpm_result);
359     if (psbs.u.resp.tpm_result != 0) {
360         error_report("tpm-emulator: TPM result for set buffer size : 0x%x %s",
361                      psbs.u.resp.tpm_result,
362                      tpm_emulator_strerror(psbs.u.resp.tpm_result));
363         return -1;
364     }
365 
366     if (actual_size) {
367         *actual_size = be32_to_cpu(psbs.u.resp.buffersize);
368     }
369 
370     trace_tpm_emulator_set_buffer_size(
371             be32_to_cpu(psbs.u.resp.buffersize),
372             be32_to_cpu(psbs.u.resp.minsize),
373             be32_to_cpu(psbs.u.resp.maxsize));
374 
375     return 0;
376 }
377 
378 static int tpm_emulator_startup_tpm_resume(TPMBackend *tb, size_t buffersize,
379                                      bool is_resume)
380 {
381     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
382     ptm_init init = {
383         .u.req.init_flags = 0,
384     };
385     ptm_res res;
386 
387     trace_tpm_emulator_startup_tpm_resume(is_resume, buffersize);
388 
389     if (buffersize != 0 &&
390         tpm_emulator_set_buffer_size(tb, buffersize, NULL) < 0) {
391         goto err_exit;
392     }
393 
394     if (is_resume) {
395         init.u.req.init_flags |= cpu_to_be32(PTM_INIT_FLAG_DELETE_VOLATILE);
396     }
397 
398     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_INIT, &init, sizeof(init),
399                              sizeof(init)) < 0) {
400         error_report("tpm-emulator: could not send INIT: %s",
401                      strerror(errno));
402         goto err_exit;
403     }
404 
405     res = be32_to_cpu(init.u.resp.tpm_result);
406     if (res) {
407         error_report("tpm-emulator: TPM result for CMD_INIT: 0x%x %s", res,
408                      tpm_emulator_strerror(res));
409         goto err_exit;
410     }
411     return 0;
412 
413 err_exit:
414     return -1;
415 }
416 
417 static int tpm_emulator_startup_tpm(TPMBackend *tb, size_t buffersize)
418 {
419     /* TPM startup will be done from post_load hook */
420     if (runstate_check(RUN_STATE_INMIGRATE)) {
421         if (buffersize != 0) {
422             return tpm_emulator_set_buffer_size(tb, buffersize, NULL);
423         }
424 
425         return 0;
426     }
427 
428     return tpm_emulator_startup_tpm_resume(tb, buffersize, false);
429 }
430 
431 static bool tpm_emulator_get_tpm_established_flag(TPMBackend *tb)
432 {
433     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
434     ptm_est est;
435 
436     if (tpm_emu->established_flag_cached) {
437         return tpm_emu->established_flag;
438     }
439 
440     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_GET_TPMESTABLISHED, &est,
441                              0, sizeof(est)) < 0) {
442         error_report("tpm-emulator: Could not get the TPM established flag: %s",
443                      strerror(errno));
444         return false;
445     }
446     trace_tpm_emulator_get_tpm_established_flag(est.u.resp.bit);
447 
448     tpm_emu->established_flag_cached = 1;
449     tpm_emu->established_flag = (est.u.resp.bit != 0);
450 
451     return tpm_emu->established_flag;
452 }
453 
454 static int tpm_emulator_reset_tpm_established_flag(TPMBackend *tb,
455                                                    uint8_t locty)
456 {
457     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
458     ptm_reset_est reset_est;
459     ptm_res res;
460 
461     /* only a TPM 2.0 will support this */
462     if (tpm_emu->tpm_version != TPM_VERSION_2_0) {
463         return 0;
464     }
465 
466     reset_est.u.req.loc = tpm_emu->cur_locty_number;
467     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_RESET_TPMESTABLISHED,
468                              &reset_est, sizeof(reset_est),
469                              sizeof(reset_est)) < 0) {
470         error_report("tpm-emulator: Could not reset the establishment bit: %s",
471                      strerror(errno));
472         return -1;
473     }
474 
475     res = be32_to_cpu(reset_est.u.resp.tpm_result);
476     if (res) {
477         error_report(
478             "tpm-emulator: TPM result for rest established flag: 0x%x %s",
479             res, tpm_emulator_strerror(res));
480         return -1;
481     }
482 
483     tpm_emu->established_flag_cached = 0;
484 
485     return 0;
486 }
487 
488 static void tpm_emulator_cancel_cmd(TPMBackend *tb)
489 {
490     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
491     ptm_res res;
492 
493     if (!TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(tpm_emu, PTM_CAP_CANCEL_TPM_CMD)) {
494         trace_tpm_emulator_cancel_cmd_not_supt();
495         return;
496     }
497 
498     /* FIXME: make the function non-blocking, or it may block a VCPU */
499     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_CANCEL_TPM_CMD, &res, 0,
500                              sizeof(res)) < 0) {
501         error_report("tpm-emulator: Could not cancel command: %s",
502                      strerror(errno));
503     } else if (res != 0) {
504         error_report("tpm-emulator: Failed to cancel TPM: 0x%x",
505                      be32_to_cpu(res));
506     }
507 }
508 
509 static TPMVersion tpm_emulator_get_tpm_version(TPMBackend *tb)
510 {
511     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
512 
513     return tpm_emu->tpm_version;
514 }
515 
516 static size_t tpm_emulator_get_buffer_size(TPMBackend *tb)
517 {
518     size_t actual_size;
519 
520     if (tpm_emulator_set_buffer_size(tb, 0, &actual_size) < 0) {
521         return 4096;
522     }
523 
524     return actual_size;
525 }
526 
527 static int tpm_emulator_block_migration(TPMEmulator *tpm_emu)
528 {
529     Error *err = NULL;
530     ptm_cap caps = PTM_CAP_GET_STATEBLOB | PTM_CAP_SET_STATEBLOB |
531                    PTM_CAP_STOP;
532 
533     if (!TPM_EMULATOR_IMPLEMENTS_ALL_CAPS(tpm_emu, caps)) {
534         error_setg(&tpm_emu->migration_blocker,
535                    "Migration disabled: TPM emulator does not support "
536                    "migration");
537         if (migrate_add_blocker(&tpm_emu->migration_blocker, &err) < 0) {
538             error_report_err(err);
539             return -1;
540         }
541     }
542 
543     return 0;
544 }
545 
546 static int tpm_emulator_prepare_data_fd(TPMEmulator *tpm_emu)
547 {
548     ptm_res res;
549     Error *err = NULL;
550     int fds[2] = { -1, -1 };
551 
552     if (qemu_socketpair(AF_UNIX, SOCK_STREAM, 0, fds) < 0) {
553         error_report("tpm-emulator: Failed to create socketpair");
554         return -1;
555     }
556 
557     qemu_chr_fe_set_msgfds(&tpm_emu->ctrl_chr, fds + 1, 1);
558 
559     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SET_DATAFD, &res, 0,
560                              sizeof(res)) < 0 || res != 0) {
561         error_report("tpm-emulator: Failed to send CMD_SET_DATAFD: %s",
562                      strerror(errno));
563         goto err_exit;
564     }
565 
566     tpm_emu->data_ioc = QIO_CHANNEL(qio_channel_socket_new_fd(fds[0], &err));
567     if (err) {
568         error_prepend(&err, "tpm-emulator: Failed to create io channel: ");
569         error_report_err(err);
570         goto err_exit;
571     }
572 
573     close(fds[1]);
574 
575     return 0;
576 
577 err_exit:
578     close(fds[0]);
579     close(fds[1]);
580     return -1;
581 }
582 
583 static int tpm_emulator_handle_device_opts(TPMEmulator *tpm_emu, QemuOpts *opts)
584 {
585     const char *value;
586     Error *err = NULL;
587     Chardev *dev;
588 
589     value = qemu_opt_get(opts, "chardev");
590     if (!value) {
591         error_report("tpm-emulator: parameter 'chardev' is missing");
592         goto err;
593     }
594 
595     dev = qemu_chr_find(value);
596     if (!dev) {
597         error_report("tpm-emulator: tpm chardev '%s' not found", value);
598         goto err;
599     }
600 
601     if (!qemu_chr_fe_init(&tpm_emu->ctrl_chr, dev, &err)) {
602         error_prepend(&err, "tpm-emulator: No valid chardev found at '%s':",
603                       value);
604         error_report_err(err);
605         goto err;
606     }
607 
608     tpm_emu->options->chardev = g_strdup(value);
609 
610     if (tpm_emulator_prepare_data_fd(tpm_emu) < 0) {
611         goto err;
612     }
613 
614     /* FIXME: tpm_util_test_tpmdev() accepts only on socket fd, as it also used
615      * by passthrough driver, which not yet using GIOChannel.
616      */
617     if (tpm_util_test_tpmdev(QIO_CHANNEL_SOCKET(tpm_emu->data_ioc)->fd,
618                              &tpm_emu->tpm_version)) {
619         error_report("'%s' is not emulating TPM device. Error: %s",
620                       tpm_emu->options->chardev, strerror(errno));
621         goto err;
622     }
623 
624     switch (tpm_emu->tpm_version) {
625     case TPM_VERSION_1_2:
626         trace_tpm_emulator_handle_device_opts_tpm12();
627         break;
628     case TPM_VERSION_2_0:
629         trace_tpm_emulator_handle_device_opts_tpm2();
630         break;
631     default:
632         trace_tpm_emulator_handle_device_opts_unspec();
633     }
634 
635     if (tpm_emulator_probe_caps(tpm_emu) ||
636         tpm_emulator_check_caps(tpm_emu)) {
637         goto err;
638     }
639 
640     return tpm_emulator_block_migration(tpm_emu);
641 
642 err:
643     trace_tpm_emulator_handle_device_opts_startup_error();
644 
645     return -1;
646 }
647 
648 static TPMBackend *tpm_emulator_create(QemuOpts *opts)
649 {
650     TPMBackend *tb = TPM_BACKEND(object_new(TYPE_TPM_EMULATOR));
651 
652     if (tpm_emulator_handle_device_opts(TPM_EMULATOR(tb), opts)) {
653         object_unref(OBJECT(tb));
654         return NULL;
655     }
656 
657     return tb;
658 }
659 
660 static TpmTypeOptions *tpm_emulator_get_tpm_options(TPMBackend *tb)
661 {
662     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
663     TpmTypeOptions *options = g_new0(TpmTypeOptions, 1);
664 
665     options->type = TPM_TYPE_EMULATOR;
666     options->u.emulator.data = QAPI_CLONE(TPMEmulatorOptions, tpm_emu->options);
667 
668     return options;
669 }
670 
671 static const QemuOptDesc tpm_emulator_cmdline_opts[] = {
672     TPM_STANDARD_CMDLINE_OPTS,
673     {
674         .name = "chardev",
675         .type = QEMU_OPT_STRING,
676         .help = "Character device to use for out-of-band control messages",
677     },
678     { /* end of list */ },
679 };
680 
681 /*
682  * Transfer a TPM state blob from the TPM into a provided buffer.
683  *
684  * @tpm_emu: TPMEmulator
685  * @type: the type of blob to transfer
686  * @tsb: the TPMSizeBuffer to fill with the blob
687  * @flags: the flags to return to the caller
688  */
689 static int tpm_emulator_get_state_blob(TPMEmulator *tpm_emu,
690                                        uint8_t type,
691                                        TPMSizedBuffer *tsb,
692                                        uint32_t *flags)
693 {
694     ptm_getstate pgs;
695     ptm_res res;
696     ssize_t n;
697     uint32_t totlength, length;
698 
699     tpm_sized_buffer_reset(tsb);
700 
701     pgs.u.req.state_flags = cpu_to_be32(PTM_STATE_FLAG_DECRYPTED);
702     pgs.u.req.type = cpu_to_be32(type);
703     pgs.u.req.offset = 0;
704 
705     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_GET_STATEBLOB,
706                              &pgs, sizeof(pgs.u.req),
707                              offsetof(ptm_getstate, u.resp.data)) < 0) {
708         error_report("tpm-emulator: could not get state blob type %d : %s",
709                      type, strerror(errno));
710         return -1;
711     }
712 
713     res = be32_to_cpu(pgs.u.resp.tpm_result);
714     if (res != 0 && (res & 0x800) == 0) {
715         error_report("tpm-emulator: Getting the stateblob (type %d) failed "
716                      "with a TPM error 0x%x %s", type, res,
717                      tpm_emulator_strerror(res));
718         return -1;
719     }
720 
721     totlength = be32_to_cpu(pgs.u.resp.totlength);
722     length = be32_to_cpu(pgs.u.resp.length);
723     if (totlength != length) {
724         error_report("tpm-emulator: Expecting to read %u bytes "
725                      "but would get %u", totlength, length);
726         return -1;
727     }
728 
729     *flags = be32_to_cpu(pgs.u.resp.state_flags);
730 
731     if (totlength > 0) {
732         tsb->buffer = g_try_malloc(totlength);
733         if (!tsb->buffer) {
734             error_report("tpm-emulator: Out of memory allocating %u bytes",
735                          totlength);
736             return -1;
737         }
738 
739         n = qemu_chr_fe_read_all(&tpm_emu->ctrl_chr, tsb->buffer, totlength);
740         if (n != totlength) {
741             error_report("tpm-emulator: Could not read stateblob (type %d); "
742                          "expected %u bytes, got %zd",
743                          type, totlength, n);
744             return -1;
745         }
746     }
747     tsb->size = totlength;
748 
749     trace_tpm_emulator_get_state_blob(type, tsb->size, *flags);
750 
751     return 0;
752 }
753 
754 static int tpm_emulator_get_state_blobs(TPMEmulator *tpm_emu)
755 {
756     TPMBlobBuffers *state_blobs = &tpm_emu->state_blobs;
757 
758     if (tpm_emulator_get_state_blob(tpm_emu, PTM_BLOB_TYPE_PERMANENT,
759                                     &state_blobs->permanent,
760                                     &state_blobs->permanent_flags) < 0 ||
761         tpm_emulator_get_state_blob(tpm_emu, PTM_BLOB_TYPE_VOLATILE,
762                                     &state_blobs->volatil,
763                                     &state_blobs->volatil_flags) < 0 ||
764         tpm_emulator_get_state_blob(tpm_emu, PTM_BLOB_TYPE_SAVESTATE,
765                                     &state_blobs->savestate,
766                                     &state_blobs->savestate_flags) < 0) {
767         goto err_exit;
768     }
769 
770     return 0;
771 
772  err_exit:
773     tpm_sized_buffer_reset(&state_blobs->volatil);
774     tpm_sized_buffer_reset(&state_blobs->permanent);
775     tpm_sized_buffer_reset(&state_blobs->savestate);
776 
777     return -1;
778 }
779 
780 /*
781  * Transfer a TPM state blob to the TPM emulator.
782  *
783  * @tpm_emu: TPMEmulator
784  * @type: the type of TPM state blob to transfer
785  * @tsb: TPMSizedBuffer containing the TPM state blob
786  * @flags: Flags describing the (encryption) state of the TPM state blob
787  */
788 static int tpm_emulator_set_state_blob(TPMEmulator *tpm_emu,
789                                        uint32_t type,
790                                        TPMSizedBuffer *tsb,
791                                        uint32_t flags)
792 {
793     ssize_t n;
794     ptm_setstate pss;
795     ptm_res tpm_result;
796 
797     if (tsb->size == 0) {
798         return 0;
799     }
800 
801     pss = (ptm_setstate) {
802         .u.req.state_flags = cpu_to_be32(flags),
803         .u.req.type = cpu_to_be32(type),
804         .u.req.length = cpu_to_be32(tsb->size),
805     };
806 
807     /* write the header only */
808     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SET_STATEBLOB, &pss,
809                              offsetof(ptm_setstate, u.req.data), 0) < 0) {
810         error_report("tpm-emulator: could not set state blob type %d : %s",
811                      type, strerror(errno));
812         return -1;
813     }
814 
815     /* now the body */
816     n = qemu_chr_fe_write_all(&tpm_emu->ctrl_chr, tsb->buffer, tsb->size);
817     if (n != tsb->size) {
818         error_report("tpm-emulator: Writing the stateblob (type %d) "
819                      "failed; could not write %u bytes, but only %zd",
820                      type, tsb->size, n);
821         return -1;
822     }
823 
824     /* now get the result */
825     n = qemu_chr_fe_read_all(&tpm_emu->ctrl_chr,
826                              (uint8_t *)&pss, sizeof(pss.u.resp));
827     if (n != sizeof(pss.u.resp)) {
828         error_report("tpm-emulator: Reading response from writing stateblob "
829                      "(type %d) failed; expected %zu bytes, got %zd", type,
830                      sizeof(pss.u.resp), n);
831         return -1;
832     }
833 
834     tpm_result = be32_to_cpu(pss.u.resp.tpm_result);
835     if (tpm_result != 0) {
836         error_report("tpm-emulator: Setting the stateblob (type %d) failed "
837                      "with a TPM error 0x%x %s", type, tpm_result,
838                      tpm_emulator_strerror(tpm_result));
839         return -1;
840     }
841 
842     trace_tpm_emulator_set_state_blob(type, tsb->size, flags);
843 
844     return 0;
845 }
846 
847 /*
848  * Set all the TPM state blobs.
849  *
850  * Returns a negative errno code in case of error.
851  */
852 static int tpm_emulator_set_state_blobs(TPMBackend *tb)
853 {
854     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
855     TPMBlobBuffers *state_blobs = &tpm_emu->state_blobs;
856 
857     trace_tpm_emulator_set_state_blobs();
858 
859     if (tpm_emulator_stop_tpm(tb) < 0) {
860         trace_tpm_emulator_set_state_blobs_error("Could not stop TPM");
861         return -EIO;
862     }
863 
864     if (tpm_emulator_set_state_blob(tpm_emu, PTM_BLOB_TYPE_PERMANENT,
865                                     &state_blobs->permanent,
866                                     state_blobs->permanent_flags) < 0 ||
867         tpm_emulator_set_state_blob(tpm_emu, PTM_BLOB_TYPE_VOLATILE,
868                                     &state_blobs->volatil,
869                                     state_blobs->volatil_flags) < 0 ||
870         tpm_emulator_set_state_blob(tpm_emu, PTM_BLOB_TYPE_SAVESTATE,
871                                     &state_blobs->savestate,
872                                     state_blobs->savestate_flags) < 0) {
873         return -EIO;
874     }
875 
876     trace_tpm_emulator_set_state_blobs_done();
877 
878     return 0;
879 }
880 
881 static int tpm_emulator_pre_save(void *opaque)
882 {
883     TPMBackend *tb = opaque;
884     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
885     int ret;
886 
887     trace_tpm_emulator_pre_save();
888 
889     tpm_backend_finish_sync(tb);
890 
891     /* get the state blobs from the TPM */
892     ret = tpm_emulator_get_state_blobs(tpm_emu);
893 
894     tpm_emu->relock_storage = ret == 0;
895 
896     return ret;
897 }
898 
899 static void tpm_emulator_vm_state_change(void *opaque, bool running,
900                                          RunState state)
901 {
902     TPMBackend *tb = opaque;
903     TPMEmulator *tpm_emu = TPM_EMULATOR(tb);
904 
905     trace_tpm_emulator_vm_state_change(running, state);
906 
907     if (!running || state != RUN_STATE_RUNNING || !tpm_emu->relock_storage) {
908         return;
909     }
910 
911     /* lock storage after migration fall-back */
912     tpm_emulator_lock_storage(tpm_emu);
913 }
914 
915 /*
916  * Load the TPM state blobs into the TPM.
917  *
918  * Returns negative errno codes in case of error.
919  */
920 static int tpm_emulator_post_load(void *opaque, int version_id)
921 {
922     TPMBackend *tb = opaque;
923     int ret;
924 
925     ret = tpm_emulator_set_state_blobs(tb);
926     if (ret < 0) {
927         return ret;
928     }
929 
930     if (tpm_emulator_startup_tpm_resume(tb, 0, true) < 0) {
931         return -EIO;
932     }
933 
934     return 0;
935 }
936 
937 static const VMStateDescription vmstate_tpm_emulator = {
938     .name = "tpm-emulator",
939     .version_id = 0,
940     .pre_save = tpm_emulator_pre_save,
941     .post_load = tpm_emulator_post_load,
942     .fields = (VMStateField[]) {
943         VMSTATE_UINT32(state_blobs.permanent_flags, TPMEmulator),
944         VMSTATE_UINT32(state_blobs.permanent.size, TPMEmulator),
945         VMSTATE_VBUFFER_ALLOC_UINT32(state_blobs.permanent.buffer,
946                                      TPMEmulator, 0, 0,
947                                      state_blobs.permanent.size),
948 
949         VMSTATE_UINT32(state_blobs.volatil_flags, TPMEmulator),
950         VMSTATE_UINT32(state_blobs.volatil.size, TPMEmulator),
951         VMSTATE_VBUFFER_ALLOC_UINT32(state_blobs.volatil.buffer,
952                                      TPMEmulator, 0, 0,
953                                      state_blobs.volatil.size),
954 
955         VMSTATE_UINT32(state_blobs.savestate_flags, TPMEmulator),
956         VMSTATE_UINT32(state_blobs.savestate.size, TPMEmulator),
957         VMSTATE_VBUFFER_ALLOC_UINT32(state_blobs.savestate.buffer,
958                                      TPMEmulator, 0, 0,
959                                      state_blobs.savestate.size),
960 
961         VMSTATE_END_OF_LIST()
962     }
963 };
964 
965 static void tpm_emulator_inst_init(Object *obj)
966 {
967     TPMEmulator *tpm_emu = TPM_EMULATOR(obj);
968 
969     trace_tpm_emulator_inst_init();
970 
971     tpm_emu->options = g_new0(TPMEmulatorOptions, 1);
972     tpm_emu->cur_locty_number = ~0;
973     qemu_mutex_init(&tpm_emu->mutex);
974     tpm_emu->vmstate =
975         qemu_add_vm_change_state_handler(tpm_emulator_vm_state_change,
976                                          tpm_emu);
977 
978     vmstate_register_any(NULL, &vmstate_tpm_emulator, obj);
979 }
980 
981 /*
982  * Gracefully shut down the external TPM
983  */
984 static void tpm_emulator_shutdown(TPMEmulator *tpm_emu)
985 {
986     ptm_res res;
987 
988     if (!tpm_emu->options->chardev) {
989         /* was never properly initialized */
990         return;
991     }
992 
993     if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SHUTDOWN, &res, 0, sizeof(res)) < 0) {
994         error_report("tpm-emulator: Could not cleanly shutdown the TPM: %s",
995                      strerror(errno));
996     } else if (res != 0) {
997         error_report("tpm-emulator: TPM result for shutdown: 0x%x %s",
998                      be32_to_cpu(res), tpm_emulator_strerror(be32_to_cpu(res)));
999     }
1000 }
1001 
1002 static void tpm_emulator_inst_finalize(Object *obj)
1003 {
1004     TPMEmulator *tpm_emu = TPM_EMULATOR(obj);
1005     TPMBlobBuffers *state_blobs = &tpm_emu->state_blobs;
1006 
1007     tpm_emulator_shutdown(tpm_emu);
1008 
1009     object_unref(OBJECT(tpm_emu->data_ioc));
1010 
1011     qemu_chr_fe_deinit(&tpm_emu->ctrl_chr, false);
1012 
1013     qapi_free_TPMEmulatorOptions(tpm_emu->options);
1014 
1015     migrate_del_blocker(&tpm_emu->migration_blocker);
1016 
1017     tpm_sized_buffer_reset(&state_blobs->volatil);
1018     tpm_sized_buffer_reset(&state_blobs->permanent);
1019     tpm_sized_buffer_reset(&state_blobs->savestate);
1020 
1021     qemu_mutex_destroy(&tpm_emu->mutex);
1022     qemu_del_vm_change_state_handler(tpm_emu->vmstate);
1023 
1024     vmstate_unregister(NULL, &vmstate_tpm_emulator, obj);
1025 }
1026 
1027 static void tpm_emulator_class_init(ObjectClass *klass, void *data)
1028 {
1029     TPMBackendClass *tbc = TPM_BACKEND_CLASS(klass);
1030 
1031     tbc->type = TPM_TYPE_EMULATOR;
1032     tbc->opts = tpm_emulator_cmdline_opts;
1033     tbc->desc = "TPM emulator backend driver";
1034     tbc->create = tpm_emulator_create;
1035     tbc->startup_tpm = tpm_emulator_startup_tpm;
1036     tbc->cancel_cmd = tpm_emulator_cancel_cmd;
1037     tbc->get_tpm_established_flag = tpm_emulator_get_tpm_established_flag;
1038     tbc->reset_tpm_established_flag = tpm_emulator_reset_tpm_established_flag;
1039     tbc->get_tpm_version = tpm_emulator_get_tpm_version;
1040     tbc->get_buffer_size = tpm_emulator_get_buffer_size;
1041     tbc->get_tpm_options = tpm_emulator_get_tpm_options;
1042 
1043     tbc->handle_request = tpm_emulator_handle_request;
1044 }
1045 
1046 static const TypeInfo tpm_emulator_info = {
1047     .name = TYPE_TPM_EMULATOR,
1048     .parent = TYPE_TPM_BACKEND,
1049     .instance_size = sizeof(TPMEmulator),
1050     .class_init = tpm_emulator_class_init,
1051     .instance_init = tpm_emulator_inst_init,
1052     .instance_finalize = tpm_emulator_inst_finalize,
1053 };
1054 
1055 static void tpm_emulator_register(void)
1056 {
1057     type_register_static(&tpm_emulator_info);
1058 }
1059 
1060 type_init(tpm_emulator_register)
1061