xref: /qemu/hw/tpm/tpm_tis_common.c (revision 43bc7f84e14083eda3959127a2346c0f7e31a7ae)
1 /*
2  * tpm_tis.c - QEMU's TPM TIS interface emulator
3  *
4  * Copyright (C) 2006,2010-2013 IBM Corporation
5  *
6  * Authors:
7  *  Stefan Berger <stefanb@us.ibm.com>
8  *  David Safford <safford@us.ibm.com>
9  *
10  * Xen 4 support: Andrease Niederl <andreas.niederl@iaik.tugraz.at>
11  *
12  * This work is licensed under the terms of the GNU GPL, version 2 or later.
13  * See the COPYING file in the top-level directory.
14  *
15  * Implementation of the TIS interface according to specs found at
16  * http://www.trustedcomputinggroup.org. This implementation currently
17  * supports version 1.3, 21 March 2013
18  * In the developers menu choose the PC Client section then find the TIS
19  * specification.
20  *
21  * TPM TIS for TPM 2 implementation following TCG PC Client Platform
22  * TPM Profile (PTP) Specification, Familiy 2.0, Revision 00.43
23  */
24 
25 #include "qemu/osdep.h"
26 #include "hw/irq.h"
27 #include "hw/isa/isa.h"
28 #include "qapi/error.h"
29 #include "qemu/module.h"
30 
31 #include "hw/acpi/tpm.h"
32 #include "hw/pci/pci_ids.h"
33 #include "hw/qdev-properties.h"
34 #include "migration/vmstate.h"
35 #include "sysemu/tpm_backend.h"
36 #include "tpm_int.h"
37 #include "tpm_util.h"
38 #include "tpm_ppi.h"
39 #include "trace.h"
40 
41 #define TPM_TIS_NUM_LOCALITIES      5     /* per spec */
42 #define TPM_TIS_LOCALITY_SHIFT      12
43 #define TPM_TIS_NO_LOCALITY         0xff
44 
45 #define TPM_TIS_IS_VALID_LOCTY(x)   ((x) < TPM_TIS_NUM_LOCALITIES)
46 
47 #define TPM_TIS_BUFFER_MAX          4096
48 
49 typedef enum {
50     TPM_TIS_STATE_IDLE = 0,
51     TPM_TIS_STATE_READY,
52     TPM_TIS_STATE_COMPLETION,
53     TPM_TIS_STATE_EXECUTION,
54     TPM_TIS_STATE_RECEPTION,
55 } TPMTISState;
56 
57 /* locality data  -- all fields are persisted */
58 typedef struct TPMLocality {
59     TPMTISState state;
60     uint8_t access;
61     uint32_t sts;
62     uint32_t iface_id;
63     uint32_t inte;
64     uint32_t ints;
65 } TPMLocality;
66 
67 typedef struct TPMState {
68     ISADevice busdev;
69     MemoryRegion mmio;
70 
71     unsigned char buffer[TPM_TIS_BUFFER_MAX];
72     uint16_t rw_offset;
73 
74     uint8_t active_locty;
75     uint8_t aborting_locty;
76     uint8_t next_locty;
77 
78     TPMLocality loc[TPM_TIS_NUM_LOCALITIES];
79 
80     qemu_irq irq;
81     uint32_t irq_num;
82 
83     TPMBackendCmd cmd;
84 
85     TPMBackend *be_driver;
86     TPMVersion be_tpm_version;
87 
88     size_t be_buffer_size;
89 
90     bool ppi_enabled;
91     TPMPPI ppi;
92 } TPMState;
93 
94 #define TPM(obj) OBJECT_CHECK(TPMState, (obj), TYPE_TPM_TIS_ISA)
95 
96 #define DEBUG_TIS 0
97 
98 /* local prototypes */
99 
100 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
101                                   unsigned size);
102 
103 /* utility functions */
104 
105 static uint8_t tpm_tis_locality_from_addr(hwaddr addr)
106 {
107     return (uint8_t)((addr >> TPM_TIS_LOCALITY_SHIFT) & 0x7);
108 }
109 
110 
111 /*
112  * Set the given flags in the STS register by clearing the register but
113  * preserving the SELFTEST_DONE and TPM_FAMILY_MASK flags and then setting
114  * the new flags.
115  *
116  * The SELFTEST_DONE flag is acquired from the backend that determines it by
117  * peeking into TPM commands.
118  *
119  * A VM suspend/resume will preserve the flag by storing it into the VM
120  * device state, but the backend will not remember it when QEMU is started
121  * again. Therefore, we cache the flag here. Once set, it will not be unset
122  * except by a reset.
123  */
124 static void tpm_tis_sts_set(TPMLocality *l, uint32_t flags)
125 {
126     l->sts &= TPM_TIS_STS_SELFTEST_DONE | TPM_TIS_STS_TPM_FAMILY_MASK;
127     l->sts |= flags;
128 }
129 
130 /*
131  * Send a request to the TPM.
132  */
133 static void tpm_tis_tpm_send(TPMState *s, uint8_t locty)
134 {
135     if (trace_event_get_state_backends(TRACE_TPM_UTIL_SHOW_BUFFER)) {
136         tpm_util_show_buffer(s->buffer, s->be_buffer_size, "To TPM");
137     }
138 
139     /*
140      * rw_offset serves as length indicator for length of data;
141      * it's reset when the response comes back
142      */
143     s->loc[locty].state = TPM_TIS_STATE_EXECUTION;
144 
145     s->cmd = (TPMBackendCmd) {
146         .locty = locty,
147         .in = s->buffer,
148         .in_len = s->rw_offset,
149         .out = s->buffer,
150         .out_len = s->be_buffer_size,
151     };
152 
153     tpm_backend_deliver_request(s->be_driver, &s->cmd);
154 }
155 
156 /* raise an interrupt if allowed */
157 static void tpm_tis_raise_irq(TPMState *s, uint8_t locty, uint32_t irqmask)
158 {
159     if (!TPM_TIS_IS_VALID_LOCTY(locty)) {
160         return;
161     }
162 
163     if ((s->loc[locty].inte & TPM_TIS_INT_ENABLED) &&
164         (s->loc[locty].inte & irqmask)) {
165         trace_tpm_tis_raise_irq(irqmask);
166         qemu_irq_raise(s->irq);
167         s->loc[locty].ints |= irqmask;
168     }
169 }
170 
171 static uint32_t tpm_tis_check_request_use_except(TPMState *s, uint8_t locty)
172 {
173     uint8_t l;
174 
175     for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
176         if (l == locty) {
177             continue;
178         }
179         if ((s->loc[l].access & TPM_TIS_ACCESS_REQUEST_USE)) {
180             return 1;
181         }
182     }
183 
184     return 0;
185 }
186 
187 static void tpm_tis_new_active_locality(TPMState *s, uint8_t new_active_locty)
188 {
189     bool change = (s->active_locty != new_active_locty);
190     bool is_seize;
191     uint8_t mask;
192 
193     if (change && TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
194         is_seize = TPM_TIS_IS_VALID_LOCTY(new_active_locty) &&
195                    s->loc[new_active_locty].access & TPM_TIS_ACCESS_SEIZE;
196 
197         if (is_seize) {
198             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY);
199         } else {
200             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY|
201                      TPM_TIS_ACCESS_REQUEST_USE);
202         }
203         /* reset flags on the old active locality */
204         s->loc[s->active_locty].access &= mask;
205 
206         if (is_seize) {
207             s->loc[s->active_locty].access |= TPM_TIS_ACCESS_BEEN_SEIZED;
208         }
209     }
210 
211     s->active_locty = new_active_locty;
212 
213     trace_tpm_tis_new_active_locality(s->active_locty);
214 
215     if (TPM_TIS_IS_VALID_LOCTY(new_active_locty)) {
216         /* set flags on the new active locality */
217         s->loc[new_active_locty].access |= TPM_TIS_ACCESS_ACTIVE_LOCALITY;
218         s->loc[new_active_locty].access &= ~(TPM_TIS_ACCESS_REQUEST_USE |
219                                                TPM_TIS_ACCESS_SEIZE);
220     }
221 
222     if (change) {
223         tpm_tis_raise_irq(s, s->active_locty, TPM_TIS_INT_LOCALITY_CHANGED);
224     }
225 }
226 
227 /* abort -- this function switches the locality */
228 static void tpm_tis_abort(TPMState *s)
229 {
230     s->rw_offset = 0;
231 
232     trace_tpm_tis_abort(s->next_locty);
233 
234     /*
235      * Need to react differently depending on who's aborting now and
236      * which locality will become active afterwards.
237      */
238     if (s->aborting_locty == s->next_locty) {
239         s->loc[s->aborting_locty].state = TPM_TIS_STATE_READY;
240         tpm_tis_sts_set(&s->loc[s->aborting_locty],
241                         TPM_TIS_STS_COMMAND_READY);
242         tpm_tis_raise_irq(s, s->aborting_locty, TPM_TIS_INT_COMMAND_READY);
243     }
244 
245     /* locality after abort is another one than the current one */
246     tpm_tis_new_active_locality(s, s->next_locty);
247 
248     s->next_locty = TPM_TIS_NO_LOCALITY;
249     /* nobody's aborting a command anymore */
250     s->aborting_locty = TPM_TIS_NO_LOCALITY;
251 }
252 
253 /* prepare aborting current command */
254 static void tpm_tis_prep_abort(TPMState *s, uint8_t locty, uint8_t newlocty)
255 {
256     uint8_t busy_locty;
257 
258     assert(TPM_TIS_IS_VALID_LOCTY(newlocty));
259 
260     s->aborting_locty = locty; /* may also be TPM_TIS_NO_LOCALITY */
261     s->next_locty = newlocty;  /* locality after successful abort */
262 
263     /*
264      * only abort a command using an interrupt if currently executing
265      * a command AND if there's a valid connection to the vTPM.
266      */
267     for (busy_locty = 0; busy_locty < TPM_TIS_NUM_LOCALITIES; busy_locty++) {
268         if (s->loc[busy_locty].state == TPM_TIS_STATE_EXECUTION) {
269             /*
270              * request the backend to cancel. Some backends may not
271              * support it
272              */
273             tpm_backend_cancel_cmd(s->be_driver);
274             return;
275         }
276     }
277 
278     tpm_tis_abort(s);
279 }
280 
281 /*
282  * Callback from the TPM to indicate that the response was received.
283  */
284 static void tpm_tis_request_completed(TPMIf *ti, int ret)
285 {
286     TPMState *s = TPM(ti);
287     uint8_t locty = s->cmd.locty;
288     uint8_t l;
289 
290     assert(TPM_TIS_IS_VALID_LOCTY(locty));
291 
292     if (s->cmd.selftest_done) {
293         for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
294             s->loc[l].sts |= TPM_TIS_STS_SELFTEST_DONE;
295         }
296     }
297 
298     /* FIXME: report error if ret != 0 */
299     tpm_tis_sts_set(&s->loc[locty],
300                     TPM_TIS_STS_VALID | TPM_TIS_STS_DATA_AVAILABLE);
301     s->loc[locty].state = TPM_TIS_STATE_COMPLETION;
302     s->rw_offset = 0;
303 
304     if (trace_event_get_state_backends(TRACE_TPM_UTIL_SHOW_BUFFER)) {
305         tpm_util_show_buffer(s->buffer, s->be_buffer_size, "From TPM");
306     }
307 
308     if (TPM_TIS_IS_VALID_LOCTY(s->next_locty)) {
309         tpm_tis_abort(s);
310     }
311 
312     tpm_tis_raise_irq(s, locty,
313                       TPM_TIS_INT_DATA_AVAILABLE | TPM_TIS_INT_STS_VALID);
314 }
315 
316 /*
317  * Read a byte of response data
318  */
319 static uint32_t tpm_tis_data_read(TPMState *s, uint8_t locty)
320 {
321     uint32_t ret = TPM_TIS_NO_DATA_BYTE;
322     uint16_t len;
323 
324     if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
325         len = MIN(tpm_cmd_get_size(&s->buffer),
326                   s->be_buffer_size);
327 
328         ret = s->buffer[s->rw_offset++];
329         if (s->rw_offset >= len) {
330             /* got last byte */
331             tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
332             tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
333         }
334         trace_tpm_tis_data_read(ret, s->rw_offset - 1);
335     }
336 
337     return ret;
338 }
339 
340 #ifdef DEBUG_TIS
341 static void tpm_tis_dump_state(void *opaque, hwaddr addr)
342 {
343     static const unsigned regs[] = {
344         TPM_TIS_REG_ACCESS,
345         TPM_TIS_REG_INT_ENABLE,
346         TPM_TIS_REG_INT_VECTOR,
347         TPM_TIS_REG_INT_STATUS,
348         TPM_TIS_REG_INTF_CAPABILITY,
349         TPM_TIS_REG_STS,
350         TPM_TIS_REG_DID_VID,
351         TPM_TIS_REG_RID,
352         0xfff};
353     int idx;
354     uint8_t locty = tpm_tis_locality_from_addr(addr);
355     hwaddr base = addr & ~0xfff;
356     TPMState *s = opaque;
357 
358     printf("tpm_tis: active locality      : %d\n"
359            "tpm_tis: state of locality %d : %d\n"
360            "tpm_tis: register dump:\n",
361            s->active_locty,
362            locty, s->loc[locty].state);
363 
364     for (idx = 0; regs[idx] != 0xfff; idx++) {
365         printf("tpm_tis: 0x%04x : 0x%08x\n", regs[idx],
366                (int)tpm_tis_mmio_read(opaque, base + regs[idx], 4));
367     }
368 
369     printf("tpm_tis: r/w offset    : %d\n"
370            "tpm_tis: result buffer : ",
371            s->rw_offset);
372     for (idx = 0;
373          idx < MIN(tpm_cmd_get_size(&s->buffer), s->be_buffer_size);
374          idx++) {
375         printf("%c%02x%s",
376                s->rw_offset == idx ? '>' : ' ',
377                s->buffer[idx],
378                ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
379     }
380     printf("\n");
381 }
382 #endif
383 
384 /*
385  * Read a register of the TIS interface
386  * See specs pages 33-63 for description of the registers
387  */
388 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
389                                   unsigned size)
390 {
391     TPMState *s = opaque;
392     uint16_t offset = addr & 0xffc;
393     uint8_t shift = (addr & 0x3) * 8;
394     uint32_t val = 0xffffffff;
395     uint8_t locty = tpm_tis_locality_from_addr(addr);
396     uint32_t avail;
397     uint8_t v;
398 
399     if (tpm_backend_had_startup_error(s->be_driver)) {
400         return 0;
401     }
402 
403     switch (offset) {
404     case TPM_TIS_REG_ACCESS:
405         /* never show the SEIZE flag even though we use it internally */
406         val = s->loc[locty].access & ~TPM_TIS_ACCESS_SEIZE;
407         /* the pending flag is always calculated */
408         if (tpm_tis_check_request_use_except(s, locty)) {
409             val |= TPM_TIS_ACCESS_PENDING_REQUEST;
410         }
411         val |= !tpm_backend_get_tpm_established_flag(s->be_driver);
412         break;
413     case TPM_TIS_REG_INT_ENABLE:
414         val = s->loc[locty].inte;
415         break;
416     case TPM_TIS_REG_INT_VECTOR:
417         val = s->irq_num;
418         break;
419     case TPM_TIS_REG_INT_STATUS:
420         val = s->loc[locty].ints;
421         break;
422     case TPM_TIS_REG_INTF_CAPABILITY:
423         switch (s->be_tpm_version) {
424         case TPM_VERSION_UNSPEC:
425             val = 0;
426             break;
427         case TPM_VERSION_1_2:
428             val = TPM_TIS_CAPABILITIES_SUPPORTED1_3;
429             break;
430         case TPM_VERSION_2_0:
431             val = TPM_TIS_CAPABILITIES_SUPPORTED2_0;
432             break;
433         }
434         break;
435     case TPM_TIS_REG_STS:
436         if (s->active_locty == locty) {
437             if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
438                 val = TPM_TIS_BURST_COUNT(
439                        MIN(tpm_cmd_get_size(&s->buffer),
440                            s->be_buffer_size)
441                        - s->rw_offset) | s->loc[locty].sts;
442             } else {
443                 avail = s->be_buffer_size - s->rw_offset;
444                 /*
445                  * byte-sized reads should not return 0x00 for 0x100
446                  * available bytes.
447                  */
448                 if (size == 1 && avail > 0xff) {
449                     avail = 0xff;
450                 }
451                 val = TPM_TIS_BURST_COUNT(avail) | s->loc[locty].sts;
452             }
453         }
454         break;
455     case TPM_TIS_REG_DATA_FIFO:
456     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
457         if (s->active_locty == locty) {
458             if (size > 4 - (addr & 0x3)) {
459                 /* prevent access beyond FIFO */
460                 size = 4 - (addr & 0x3);
461             }
462             val = 0;
463             shift = 0;
464             while (size > 0) {
465                 switch (s->loc[locty].state) {
466                 case TPM_TIS_STATE_COMPLETION:
467                     v = tpm_tis_data_read(s, locty);
468                     break;
469                 default:
470                     v = TPM_TIS_NO_DATA_BYTE;
471                     break;
472                 }
473                 val |= (v << shift);
474                 shift += 8;
475                 size--;
476             }
477             shift = 0; /* no more adjustments */
478         }
479         break;
480     case TPM_TIS_REG_INTERFACE_ID:
481         val = s->loc[locty].iface_id;
482         break;
483     case TPM_TIS_REG_DID_VID:
484         val = (TPM_TIS_TPM_DID << 16) | TPM_TIS_TPM_VID;
485         break;
486     case TPM_TIS_REG_RID:
487         val = TPM_TIS_TPM_RID;
488         break;
489 #ifdef DEBUG_TIS
490     case TPM_TIS_REG_DEBUG:
491         tpm_tis_dump_state(opaque, addr);
492         break;
493 #endif
494     }
495 
496     if (shift) {
497         val >>= shift;
498     }
499 
500     trace_tpm_tis_mmio_read(size, addr, val);
501 
502     return val;
503 }
504 
505 /*
506  * Write a value to a register of the TIS interface
507  * See specs pages 33-63 for description of the registers
508  */
509 static void tpm_tis_mmio_write(void *opaque, hwaddr addr,
510                                uint64_t val, unsigned size)
511 {
512     TPMState *s = opaque;
513     uint16_t off = addr & 0xffc;
514     uint8_t shift = (addr & 0x3) * 8;
515     uint8_t locty = tpm_tis_locality_from_addr(addr);
516     uint8_t active_locty, l;
517     int c, set_new_locty = 1;
518     uint16_t len;
519     uint32_t mask = (size == 1) ? 0xff : ((size == 2) ? 0xffff : ~0);
520 
521     trace_tpm_tis_mmio_write(size, addr, val);
522 
523     if (locty == 4) {
524         trace_tpm_tis_mmio_write_locty4();
525         return;
526     }
527 
528     if (tpm_backend_had_startup_error(s->be_driver)) {
529         return;
530     }
531 
532     val &= mask;
533 
534     if (shift) {
535         val <<= shift;
536         mask <<= shift;
537     }
538 
539     mask ^= 0xffffffff;
540 
541     switch (off) {
542     case TPM_TIS_REG_ACCESS:
543 
544         if ((val & TPM_TIS_ACCESS_SEIZE)) {
545             val &= ~(TPM_TIS_ACCESS_REQUEST_USE |
546                      TPM_TIS_ACCESS_ACTIVE_LOCALITY);
547         }
548 
549         active_locty = s->active_locty;
550 
551         if ((val & TPM_TIS_ACCESS_ACTIVE_LOCALITY)) {
552             /* give up locality if currently owned */
553             if (s->active_locty == locty) {
554                 trace_tpm_tis_mmio_write_release_locty(locty);
555 
556                 uint8_t newlocty = TPM_TIS_NO_LOCALITY;
557                 /* anybody wants the locality ? */
558                 for (c = TPM_TIS_NUM_LOCALITIES - 1; c >= 0; c--) {
559                     if ((s->loc[c].access & TPM_TIS_ACCESS_REQUEST_USE)) {
560                         trace_tpm_tis_mmio_write_locty_req_use(c);
561                         newlocty = c;
562                         break;
563                     }
564                 }
565                 trace_tpm_tis_mmio_write_next_locty(newlocty);
566 
567                 if (TPM_TIS_IS_VALID_LOCTY(newlocty)) {
568                     set_new_locty = 0;
569                     tpm_tis_prep_abort(s, locty, newlocty);
570                 } else {
571                     active_locty = TPM_TIS_NO_LOCALITY;
572                 }
573             } else {
574                 /* not currently the owner; clear a pending request */
575                 s->loc[locty].access &= ~TPM_TIS_ACCESS_REQUEST_USE;
576             }
577         }
578 
579         if ((val & TPM_TIS_ACCESS_BEEN_SEIZED)) {
580             s->loc[locty].access &= ~TPM_TIS_ACCESS_BEEN_SEIZED;
581         }
582 
583         if ((val & TPM_TIS_ACCESS_SEIZE)) {
584             /*
585              * allow seize if a locality is active and the requesting
586              * locality is higher than the one that's active
587              * OR
588              * allow seize for requesting locality if no locality is
589              * active
590              */
591             while ((TPM_TIS_IS_VALID_LOCTY(s->active_locty) &&
592                     locty > s->active_locty) ||
593                     !TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
594                 bool higher_seize = FALSE;
595 
596                 /* already a pending SEIZE ? */
597                 if ((s->loc[locty].access & TPM_TIS_ACCESS_SEIZE)) {
598                     break;
599                 }
600 
601                 /* check for ongoing seize by a higher locality */
602                 for (l = locty + 1; l < TPM_TIS_NUM_LOCALITIES; l++) {
603                     if ((s->loc[l].access & TPM_TIS_ACCESS_SEIZE)) {
604                         higher_seize = TRUE;
605                         break;
606                     }
607                 }
608 
609                 if (higher_seize) {
610                     break;
611                 }
612 
613                 /* cancel any seize by a lower locality */
614                 for (l = 0; l < locty; l++) {
615                     s->loc[l].access &= ~TPM_TIS_ACCESS_SEIZE;
616                 }
617 
618                 s->loc[locty].access |= TPM_TIS_ACCESS_SEIZE;
619 
620                 trace_tpm_tis_mmio_write_locty_seized(locty, s->active_locty);
621                 trace_tpm_tis_mmio_write_init_abort();
622 
623                 set_new_locty = 0;
624                 tpm_tis_prep_abort(s, s->active_locty, locty);
625                 break;
626             }
627         }
628 
629         if ((val & TPM_TIS_ACCESS_REQUEST_USE)) {
630             if (s->active_locty != locty) {
631                 if (TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
632                     s->loc[locty].access |= TPM_TIS_ACCESS_REQUEST_USE;
633                 } else {
634                     /* no locality active -> make this one active now */
635                     active_locty = locty;
636                 }
637             }
638         }
639 
640         if (set_new_locty) {
641             tpm_tis_new_active_locality(s, active_locty);
642         }
643 
644         break;
645     case TPM_TIS_REG_INT_ENABLE:
646         if (s->active_locty != locty) {
647             break;
648         }
649 
650         s->loc[locty].inte &= mask;
651         s->loc[locty].inte |= (val & (TPM_TIS_INT_ENABLED |
652                                         TPM_TIS_INT_POLARITY_MASK |
653                                         TPM_TIS_INTERRUPTS_SUPPORTED));
654         break;
655     case TPM_TIS_REG_INT_VECTOR:
656         /* hard wired -- ignore */
657         break;
658     case TPM_TIS_REG_INT_STATUS:
659         if (s->active_locty != locty) {
660             break;
661         }
662 
663         /* clearing of interrupt flags */
664         if (((val & TPM_TIS_INTERRUPTS_SUPPORTED)) &&
665             (s->loc[locty].ints & TPM_TIS_INTERRUPTS_SUPPORTED)) {
666             s->loc[locty].ints &= ~val;
667             if (s->loc[locty].ints == 0) {
668                 qemu_irq_lower(s->irq);
669                 trace_tpm_tis_mmio_write_lowering_irq();
670             }
671         }
672         s->loc[locty].ints &= ~(val & TPM_TIS_INTERRUPTS_SUPPORTED);
673         break;
674     case TPM_TIS_REG_STS:
675         if (s->active_locty != locty) {
676             break;
677         }
678 
679         if (s->be_tpm_version == TPM_VERSION_2_0) {
680             /* some flags that are only supported for TPM 2 */
681             if (val & TPM_TIS_STS_COMMAND_CANCEL) {
682                 if (s->loc[locty].state == TPM_TIS_STATE_EXECUTION) {
683                     /*
684                      * request the backend to cancel. Some backends may not
685                      * support it
686                      */
687                     tpm_backend_cancel_cmd(s->be_driver);
688                 }
689             }
690 
691             if (val & TPM_TIS_STS_RESET_ESTABLISHMENT_BIT) {
692                 if (locty == 3 || locty == 4) {
693                     tpm_backend_reset_tpm_established_flag(s->be_driver, locty);
694                 }
695             }
696         }
697 
698         val &= (TPM_TIS_STS_COMMAND_READY | TPM_TIS_STS_TPM_GO |
699                 TPM_TIS_STS_RESPONSE_RETRY);
700 
701         if (val == TPM_TIS_STS_COMMAND_READY) {
702             switch (s->loc[locty].state) {
703 
704             case TPM_TIS_STATE_READY:
705                 s->rw_offset = 0;
706             break;
707 
708             case TPM_TIS_STATE_IDLE:
709                 tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_COMMAND_READY);
710                 s->loc[locty].state = TPM_TIS_STATE_READY;
711                 tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
712             break;
713 
714             case TPM_TIS_STATE_EXECUTION:
715             case TPM_TIS_STATE_RECEPTION:
716                 /* abort currently running command */
717                 trace_tpm_tis_mmio_write_init_abort();
718                 tpm_tis_prep_abort(s, locty, locty);
719             break;
720 
721             case TPM_TIS_STATE_COMPLETION:
722                 s->rw_offset = 0;
723                 /* shortcut to ready state with C/R set */
724                 s->loc[locty].state = TPM_TIS_STATE_READY;
725                 if (!(s->loc[locty].sts & TPM_TIS_STS_COMMAND_READY)) {
726                     tpm_tis_sts_set(&s->loc[locty],
727                                     TPM_TIS_STS_COMMAND_READY);
728                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
729                 }
730                 s->loc[locty].sts &= ~(TPM_TIS_STS_DATA_AVAILABLE);
731             break;
732 
733             }
734         } else if (val == TPM_TIS_STS_TPM_GO) {
735             switch (s->loc[locty].state) {
736             case TPM_TIS_STATE_RECEPTION:
737                 if ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) == 0) {
738                     tpm_tis_tpm_send(s, locty);
739                 }
740                 break;
741             default:
742                 /* ignore */
743                 break;
744             }
745         } else if (val == TPM_TIS_STS_RESPONSE_RETRY) {
746             switch (s->loc[locty].state) {
747             case TPM_TIS_STATE_COMPLETION:
748                 s->rw_offset = 0;
749                 tpm_tis_sts_set(&s->loc[locty],
750                                 TPM_TIS_STS_VALID|
751                                 TPM_TIS_STS_DATA_AVAILABLE);
752                 break;
753             default:
754                 /* ignore */
755                 break;
756             }
757         }
758         break;
759     case TPM_TIS_REG_DATA_FIFO:
760     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
761         /* data fifo */
762         if (s->active_locty != locty) {
763             break;
764         }
765 
766         if (s->loc[locty].state == TPM_TIS_STATE_IDLE ||
767             s->loc[locty].state == TPM_TIS_STATE_EXECUTION ||
768             s->loc[locty].state == TPM_TIS_STATE_COMPLETION) {
769             /* drop the byte */
770         } else {
771             trace_tpm_tis_mmio_write_data2send(val, size);
772             if (s->loc[locty].state == TPM_TIS_STATE_READY) {
773                 s->loc[locty].state = TPM_TIS_STATE_RECEPTION;
774                 tpm_tis_sts_set(&s->loc[locty],
775                                 TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
776             }
777 
778             val >>= shift;
779             if (size > 4 - (addr & 0x3)) {
780                 /* prevent access beyond FIFO */
781                 size = 4 - (addr & 0x3);
782             }
783 
784             while ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) && size > 0) {
785                 if (s->rw_offset < s->be_buffer_size) {
786                     s->buffer[s->rw_offset++] =
787                         (uint8_t)val;
788                     val >>= 8;
789                     size--;
790                 } else {
791                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
792                 }
793             }
794 
795             /* check for complete packet */
796             if (s->rw_offset > 5 &&
797                 (s->loc[locty].sts & TPM_TIS_STS_EXPECT)) {
798                 /* we have a packet length - see if we have all of it */
799                 bool need_irq = !(s->loc[locty].sts & TPM_TIS_STS_VALID);
800 
801                 len = tpm_cmd_get_size(&s->buffer);
802                 if (len > s->rw_offset) {
803                     tpm_tis_sts_set(&s->loc[locty],
804                                     TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
805                 } else {
806                     /* packet complete */
807                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
808                 }
809                 if (need_irq) {
810                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
811                 }
812             }
813         }
814         break;
815     case TPM_TIS_REG_INTERFACE_ID:
816         if (val & TPM_TIS_IFACE_ID_INT_SEL_LOCK) {
817             for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
818                 s->loc[l].iface_id |= TPM_TIS_IFACE_ID_INT_SEL_LOCK;
819             }
820         }
821         break;
822     }
823 }
824 
825 static const MemoryRegionOps tpm_tis_memory_ops = {
826     .read = tpm_tis_mmio_read,
827     .write = tpm_tis_mmio_write,
828     .endianness = DEVICE_LITTLE_ENDIAN,
829     .valid = {
830         .min_access_size = 1,
831         .max_access_size = 4,
832     },
833 };
834 
835 /*
836  * Get the TPMVersion of the backend device being used
837  */
838 static enum TPMVersion tpm_tis_get_tpm_version(TPMIf *ti)
839 {
840     TPMState *s = TPM(ti);
841 
842     if (tpm_backend_had_startup_error(s->be_driver)) {
843         return TPM_VERSION_UNSPEC;
844     }
845 
846     return tpm_backend_get_tpm_version(s->be_driver);
847 }
848 
849 /*
850  * This function is called when the machine starts, resets or due to
851  * S3 resume.
852  */
853 static void tpm_tis_reset(DeviceState *dev)
854 {
855     TPMState *s = TPM(dev);
856     int c;
857 
858     s->be_tpm_version = tpm_backend_get_tpm_version(s->be_driver);
859     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->be_driver),
860                             TPM_TIS_BUFFER_MAX);
861 
862     if (s->ppi_enabled) {
863         tpm_ppi_reset(&s->ppi);
864     }
865     tpm_backend_reset(s->be_driver);
866 
867     s->active_locty = TPM_TIS_NO_LOCALITY;
868     s->next_locty = TPM_TIS_NO_LOCALITY;
869     s->aborting_locty = TPM_TIS_NO_LOCALITY;
870 
871     for (c = 0; c < TPM_TIS_NUM_LOCALITIES; c++) {
872         s->loc[c].access = TPM_TIS_ACCESS_TPM_REG_VALID_STS;
873         switch (s->be_tpm_version) {
874         case TPM_VERSION_UNSPEC:
875             break;
876         case TPM_VERSION_1_2:
877             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY1_2;
878             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3;
879             break;
880         case TPM_VERSION_2_0:
881             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY2_0;
882             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS2_0;
883             break;
884         }
885         s->loc[c].inte = TPM_TIS_INT_POLARITY_LOW_LEVEL;
886         s->loc[c].ints = 0;
887         s->loc[c].state = TPM_TIS_STATE_IDLE;
888 
889         s->rw_offset = 0;
890     }
891 
892     if (tpm_backend_startup_tpm(s->be_driver, s->be_buffer_size) < 0) {
893         exit(1);
894     }
895 }
896 
897 /* persistent state handling */
898 
899 static int tpm_tis_pre_save(void *opaque)
900 {
901     TPMState *s = opaque;
902     uint8_t locty = s->active_locty;
903 
904     trace_tpm_tis_pre_save(locty, s->rw_offset);
905 
906     if (DEBUG_TIS) {
907         tpm_tis_dump_state(opaque, 0);
908     }
909 
910     /*
911      * Synchronize with backend completion.
912      */
913     tpm_backend_finish_sync(s->be_driver);
914 
915     return 0;
916 }
917 
918 static const VMStateDescription vmstate_locty = {
919     .name = "tpm-tis/locty",
920     .version_id = 0,
921     .fields      = (VMStateField[]) {
922         VMSTATE_UINT32(state, TPMLocality),
923         VMSTATE_UINT32(inte, TPMLocality),
924         VMSTATE_UINT32(ints, TPMLocality),
925         VMSTATE_UINT8(access, TPMLocality),
926         VMSTATE_UINT32(sts, TPMLocality),
927         VMSTATE_UINT32(iface_id, TPMLocality),
928         VMSTATE_END_OF_LIST(),
929     }
930 };
931 
932 static const VMStateDescription vmstate_tpm_tis = {
933     .name = "tpm-tis",
934     .version_id = 0,
935     .pre_save  = tpm_tis_pre_save,
936     .fields = (VMStateField[]) {
937         VMSTATE_BUFFER(buffer, TPMState),
938         VMSTATE_UINT16(rw_offset, TPMState),
939         VMSTATE_UINT8(active_locty, TPMState),
940         VMSTATE_UINT8(aborting_locty, TPMState),
941         VMSTATE_UINT8(next_locty, TPMState),
942 
943         VMSTATE_STRUCT_ARRAY(loc, TPMState, TPM_TIS_NUM_LOCALITIES, 0,
944                              vmstate_locty, TPMLocality),
945 
946         VMSTATE_END_OF_LIST()
947     }
948 };
949 
950 static Property tpm_tis_properties[] = {
951     DEFINE_PROP_UINT32("irq", TPMState, irq_num, TPM_TIS_IRQ),
952     DEFINE_PROP_TPMBE("tpmdev", TPMState, be_driver),
953     DEFINE_PROP_BOOL("ppi", TPMState, ppi_enabled, true),
954     DEFINE_PROP_END_OF_LIST(),
955 };
956 
957 static void tpm_tis_realizefn(DeviceState *dev, Error **errp)
958 {
959     TPMState *s = TPM(dev);
960 
961     if (!tpm_find()) {
962         error_setg(errp, "at most one TPM device is permitted");
963         return;
964     }
965 
966     if (!s->be_driver) {
967         error_setg(errp, "'tpmdev' property is required");
968         return;
969     }
970     if (s->irq_num > 15) {
971         error_setg(errp, "IRQ %d is outside valid range of 0 to 15",
972                    s->irq_num);
973         return;
974     }
975 
976     isa_init_irq(&s->busdev, &s->irq, s->irq_num);
977 
978     memory_region_add_subregion(isa_address_space(ISA_DEVICE(dev)),
979                                 TPM_TIS_ADDR_BASE, &s->mmio);
980 
981     if (s->ppi_enabled) {
982         tpm_ppi_init(&s->ppi, isa_address_space(ISA_DEVICE(dev)),
983                      TPM_PPI_ADDR_BASE, OBJECT(s));
984     }
985 }
986 
987 static void tpm_tis_initfn(Object *obj)
988 {
989     TPMState *s = TPM(obj);
990 
991     memory_region_init_io(&s->mmio, OBJECT(s), &tpm_tis_memory_ops,
992                           s, "tpm-tis-mmio",
993                           TPM_TIS_NUM_LOCALITIES << TPM_TIS_LOCALITY_SHIFT);
994 }
995 
996 static void tpm_tis_class_init(ObjectClass *klass, void *data)
997 {
998     DeviceClass *dc = DEVICE_CLASS(klass);
999     TPMIfClass *tc = TPM_IF_CLASS(klass);
1000 
1001     dc->realize = tpm_tis_realizefn;
1002     device_class_set_props(dc, tpm_tis_properties);
1003     dc->reset = tpm_tis_reset;
1004     dc->vmsd  = &vmstate_tpm_tis;
1005     tc->model = TPM_MODEL_TPM_TIS;
1006     tc->get_version = tpm_tis_get_tpm_version;
1007     tc->request_completed = tpm_tis_request_completed;
1008 }
1009 
1010 static const TypeInfo tpm_tis_info = {
1011     .name = TYPE_TPM_TIS_ISA,
1012     .parent = TYPE_ISA_DEVICE,
1013     .instance_size = sizeof(TPMState),
1014     .instance_init = tpm_tis_initfn,
1015     .class_init  = tpm_tis_class_init,
1016     .interfaces = (InterfaceInfo[]) {
1017         { TYPE_TPM_IF },
1018         { }
1019     }
1020 };
1021 
1022 static void tpm_tis_register(void)
1023 {
1024     type_register_static(&tpm_tis_info);
1025 }
1026 
1027 type_init(tpm_tis_register)
1028