xref: /openbmc/qemu/target/riscv/debug.c (revision 2e1cacfb)
1 /*
2  * QEMU RISC-V Native Debug Support
3  *
4  * Copyright (c) 2022 Wind River Systems, Inc.
5  *
6  * Author:
7  *   Bin Meng <bin.meng@windriver.com>
8  *
9  * This provides the native debug support via the Trigger Module, as defined
10  * in the RISC-V Debug Specification:
11  * https://github.com/riscv/riscv-debug-spec/raw/master/riscv-debug-stable.pdf
12  *
13  * This program is free software; you can redistribute it and/or modify it
14  * under the terms and conditions of the GNU General Public License,
15  * version 2 or later, as published by the Free Software Foundation.
16  *
17  * This program is distributed in the hope it will be useful, but WITHOUT
18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
20  * more details.
21  *
22  * You should have received a copy of the GNU General Public License along with
23  * this program.  If not, see <http://www.gnu.org/licenses/>.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "qemu/log.h"
28 #include "qapi/error.h"
29 #include "cpu.h"
30 #include "trace.h"
31 #include "exec/exec-all.h"
32 #include "exec/helper-proto.h"
33 #include "sysemu/cpu-timers.h"
34 
35 /*
36  * The following M-mode trigger CSRs are implemented:
37  *
38  * - tselect
39  * - tdata1
40  * - tdata2
41  * - tdata3
42  * - tinfo
43  *
44  * The following triggers are initialized by default:
45  *
46  * Index | Type |          tdata mapping | Description
47  * ------+------+------------------------+------------
48  *     0 |    2 |         tdata1, tdata2 | Address / Data Match
49  *     1 |    2 |         tdata1, tdata2 | Address / Data Match
50  */
51 
52 /* tdata availability of a trigger */
53 typedef bool tdata_avail[TDATA_NUM];
54 
55 static tdata_avail tdata_mapping[TRIGGER_TYPE_NUM] = {
56     [TRIGGER_TYPE_NO_EXIST] = { false, false, false },
57     [TRIGGER_TYPE_AD_MATCH] = { true, true, true },
58     [TRIGGER_TYPE_INST_CNT] = { true, false, true },
59     [TRIGGER_TYPE_INT] = { true, true, true },
60     [TRIGGER_TYPE_EXCP] = { true, true, true },
61     [TRIGGER_TYPE_AD_MATCH6] = { true, true, true },
62     [TRIGGER_TYPE_EXT_SRC] = { true, false, false },
63     [TRIGGER_TYPE_UNAVAIL] = { true, true, true }
64 };
65 
66 /* only breakpoint size 1/2/4/8 supported */
67 static int access_size[SIZE_NUM] = {
68     [SIZE_ANY] = 0,
69     [SIZE_1B]  = 1,
70     [SIZE_2B]  = 2,
71     [SIZE_4B]  = 4,
72     [SIZE_6B]  = -1,
73     [SIZE_8B]  = 8,
74     [6 ... 15] = -1,
75 };
76 
77 static inline target_ulong extract_trigger_type(CPURISCVState *env,
78                                                 target_ulong tdata1)
79 {
80     switch (riscv_cpu_mxl(env)) {
81     case MXL_RV32:
82         return extract32(tdata1, 28, 4);
83     case MXL_RV64:
84     case MXL_RV128:
85         return extract64(tdata1, 60, 4);
86     default:
87         g_assert_not_reached();
88     }
89 }
90 
91 static inline target_ulong get_trigger_type(CPURISCVState *env,
92                                             target_ulong trigger_index)
93 {
94     return extract_trigger_type(env, env->tdata1[trigger_index]);
95 }
96 
97 static trigger_action_t get_trigger_action(CPURISCVState *env,
98                                            target_ulong trigger_index)
99 {
100     target_ulong tdata1 = env->tdata1[trigger_index];
101     int trigger_type = get_trigger_type(env, trigger_index);
102     trigger_action_t action = DBG_ACTION_NONE;
103 
104     switch (trigger_type) {
105     case TRIGGER_TYPE_AD_MATCH:
106         action = (tdata1 & TYPE2_ACTION) >> 12;
107         break;
108     case TRIGGER_TYPE_AD_MATCH6:
109         action = (tdata1 & TYPE6_ACTION) >> 12;
110         break;
111     case TRIGGER_TYPE_INST_CNT:
112     case TRIGGER_TYPE_INT:
113     case TRIGGER_TYPE_EXCP:
114     case TRIGGER_TYPE_EXT_SRC:
115         qemu_log_mask(LOG_UNIMP, "trigger type: %d is not supported\n",
116                       trigger_type);
117         break;
118     case TRIGGER_TYPE_NO_EXIST:
119     case TRIGGER_TYPE_UNAVAIL:
120         qemu_log_mask(LOG_GUEST_ERROR, "trigger type: %d does not exit\n",
121                       trigger_type);
122         break;
123     default:
124         g_assert_not_reached();
125     }
126 
127     return action;
128 }
129 
130 static inline target_ulong build_tdata1(CPURISCVState *env,
131                                         trigger_type_t type,
132                                         bool dmode, target_ulong data)
133 {
134     target_ulong tdata1;
135 
136     switch (riscv_cpu_mxl(env)) {
137     case MXL_RV32:
138         tdata1 = RV32_TYPE(type) |
139                  (dmode ? RV32_DMODE : 0) |
140                  (data & RV32_DATA_MASK);
141         break;
142     case MXL_RV64:
143     case MXL_RV128:
144         tdata1 = RV64_TYPE(type) |
145                  (dmode ? RV64_DMODE : 0) |
146                  (data & RV64_DATA_MASK);
147         break;
148     default:
149         g_assert_not_reached();
150     }
151 
152     return tdata1;
153 }
154 
155 bool tdata_available(CPURISCVState *env, int tdata_index)
156 {
157     int trigger_type = get_trigger_type(env, env->trigger_cur);
158 
159     if (unlikely(tdata_index >= TDATA_NUM)) {
160         return false;
161     }
162 
163     return tdata_mapping[trigger_type][tdata_index];
164 }
165 
166 target_ulong tselect_csr_read(CPURISCVState *env)
167 {
168     return env->trigger_cur;
169 }
170 
171 void tselect_csr_write(CPURISCVState *env, target_ulong val)
172 {
173     if (val < RV_MAX_TRIGGERS) {
174         env->trigger_cur = val;
175     }
176 }
177 
178 static target_ulong tdata1_validate(CPURISCVState *env, target_ulong val,
179                                     trigger_type_t t)
180 {
181     uint32_t type, dmode;
182     target_ulong tdata1;
183 
184     switch (riscv_cpu_mxl(env)) {
185     case MXL_RV32:
186         type = extract32(val, 28, 4);
187         dmode = extract32(val, 27, 1);
188         tdata1 = RV32_TYPE(t);
189         break;
190     case MXL_RV64:
191     case MXL_RV128:
192         type = extract64(val, 60, 4);
193         dmode = extract64(val, 59, 1);
194         tdata1 = RV64_TYPE(t);
195         break;
196     default:
197         g_assert_not_reached();
198     }
199 
200     if (type != t) {
201         qemu_log_mask(LOG_GUEST_ERROR,
202                       "ignoring type write to tdata1 register\n");
203     }
204 
205     if (dmode != 0) {
206         qemu_log_mask(LOG_UNIMP, "debug mode is not supported\n");
207     }
208 
209     return tdata1;
210 }
211 
212 static inline void warn_always_zero_bit(target_ulong val, target_ulong mask,
213                                         const char *msg)
214 {
215     if (val & mask) {
216         qemu_log_mask(LOG_UNIMP, "%s bit is always zero\n", msg);
217     }
218 }
219 
220 static target_ulong textra_validate(CPURISCVState *env, target_ulong tdata3)
221 {
222     target_ulong mhvalue, mhselect;
223     target_ulong mhselect_new;
224     target_ulong textra;
225     const uint32_t mhselect_no_rvh[8] = { 0, 0, 0, 0, 4, 4, 4, 4 };
226 
227     switch (riscv_cpu_mxl(env)) {
228     case MXL_RV32:
229         mhvalue  = get_field(tdata3, TEXTRA32_MHVALUE);
230         mhselect = get_field(tdata3, TEXTRA32_MHSELECT);
231         /* Validate unimplemented (always zero) bits */
232         warn_always_zero_bit(tdata3, (target_ulong)TEXTRA32_SBYTEMASK,
233                              "sbytemask");
234         warn_always_zero_bit(tdata3, (target_ulong)TEXTRA32_SVALUE,
235                              "svalue");
236         warn_always_zero_bit(tdata3, (target_ulong)TEXTRA32_SSELECT,
237                              "sselect");
238         break;
239     case MXL_RV64:
240     case MXL_RV128:
241         mhvalue  = get_field(tdata3, TEXTRA64_MHVALUE);
242         mhselect = get_field(tdata3, TEXTRA64_MHSELECT);
243         /* Validate unimplemented (always zero) bits */
244         warn_always_zero_bit(tdata3, (target_ulong)TEXTRA64_SBYTEMASK,
245                              "sbytemask");
246         warn_always_zero_bit(tdata3, (target_ulong)TEXTRA64_SVALUE,
247                              "svalue");
248         warn_always_zero_bit(tdata3, (target_ulong)TEXTRA64_SSELECT,
249                              "sselect");
250         break;
251     default:
252         g_assert_not_reached();
253     }
254 
255     /* Validate mhselect. */
256     mhselect_new = mhselect_no_rvh[mhselect];
257     if (mhselect != mhselect_new) {
258         qemu_log_mask(LOG_UNIMP, "mhselect only supports 0 or 4 for now\n");
259     }
260 
261     /* Write legal values into textra */
262     textra = 0;
263     switch (riscv_cpu_mxl(env)) {
264     case MXL_RV32:
265         textra = set_field(textra, TEXTRA32_MHVALUE,  mhvalue);
266         textra = set_field(textra, TEXTRA32_MHSELECT, mhselect_new);
267         break;
268     case MXL_RV64:
269     case MXL_RV128:
270         textra = set_field(textra, TEXTRA64_MHVALUE,  mhvalue);
271         textra = set_field(textra, TEXTRA64_MHSELECT, mhselect_new);
272         break;
273     default:
274         g_assert_not_reached();
275     }
276 
277     return textra;
278 }
279 
280 static void do_trigger_action(CPURISCVState *env, target_ulong trigger_index)
281 {
282     trigger_action_t action = get_trigger_action(env, trigger_index);
283 
284     switch (action) {
285     case DBG_ACTION_NONE:
286         break;
287     case DBG_ACTION_BP:
288         riscv_raise_exception(env, RISCV_EXCP_BREAKPOINT, 0);
289         break;
290     case DBG_ACTION_DBG_MODE:
291     case DBG_ACTION_TRACE0:
292     case DBG_ACTION_TRACE1:
293     case DBG_ACTION_TRACE2:
294     case DBG_ACTION_TRACE3:
295     case DBG_ACTION_EXT_DBG0:
296     case DBG_ACTION_EXT_DBG1:
297         qemu_log_mask(LOG_UNIMP, "action: %d is not supported\n", action);
298         break;
299     default:
300         g_assert_not_reached();
301     }
302 }
303 
304 /*
305  * Check the privilege level of specific trigger matches CPU's current privilege
306  * level.
307  */
308 static bool trigger_priv_match(CPURISCVState *env, trigger_type_t type,
309                                int trigger_index)
310 {
311     target_ulong ctrl = env->tdata1[trigger_index];
312 
313     switch (type) {
314     case TRIGGER_TYPE_AD_MATCH:
315         /* type 2 trigger cannot be fired in VU/VS mode */
316         if (env->virt_enabled) {
317             return false;
318         }
319         /* check U/S/M bit against current privilege level */
320         if ((ctrl >> 3) & BIT(env->priv)) {
321             return true;
322         }
323         break;
324     case TRIGGER_TYPE_AD_MATCH6:
325         if (env->virt_enabled) {
326             /* check VU/VS bit against current privilege level */
327             if ((ctrl >> 23) & BIT(env->priv)) {
328                 return true;
329             }
330         } else {
331             /* check U/S/M bit against current privilege level */
332             if ((ctrl >> 3) & BIT(env->priv)) {
333                 return true;
334             }
335         }
336         break;
337     case TRIGGER_TYPE_INST_CNT:
338         if (env->virt_enabled) {
339             /* check VU/VS bit against current privilege level */
340             if ((ctrl >> 25) & BIT(env->priv)) {
341                 return true;
342             }
343         } else {
344             /* check U/S/M bit against current privilege level */
345             if ((ctrl >> 6) & BIT(env->priv)) {
346                 return true;
347             }
348         }
349         break;
350     case TRIGGER_TYPE_INT:
351     case TRIGGER_TYPE_EXCP:
352     case TRIGGER_TYPE_EXT_SRC:
353         qemu_log_mask(LOG_UNIMP, "trigger type: %d is not supported\n", type);
354         break;
355     case TRIGGER_TYPE_NO_EXIST:
356     case TRIGGER_TYPE_UNAVAIL:
357         qemu_log_mask(LOG_GUEST_ERROR, "trigger type: %d does not exist\n",
358                       type);
359         break;
360     default:
361         g_assert_not_reached();
362     }
363 
364     return false;
365 }
366 
367 static bool trigger_textra_match(CPURISCVState *env, trigger_type_t type,
368                                  int trigger_index)
369 {
370     target_ulong textra = env->tdata3[trigger_index];
371     target_ulong mhvalue, mhselect;
372 
373     if (type < TRIGGER_TYPE_AD_MATCH || type > TRIGGER_TYPE_AD_MATCH6) {
374         /* textra checking is only applicable when type is 2, 3, 4, 5, or 6 */
375         return true;
376     }
377 
378     switch (riscv_cpu_mxl(env)) {
379     case MXL_RV32:
380         mhvalue  = get_field(textra, TEXTRA32_MHVALUE);
381         mhselect = get_field(textra, TEXTRA32_MHSELECT);
382         break;
383     case MXL_RV64:
384     case MXL_RV128:
385         mhvalue  = get_field(textra, TEXTRA64_MHVALUE);
386         mhselect = get_field(textra, TEXTRA64_MHSELECT);
387         break;
388     default:
389         g_assert_not_reached();
390     }
391 
392     /* Check mhvalue and mhselect. */
393     switch (mhselect) {
394     case MHSELECT_IGNORE:
395         break;
396     case MHSELECT_MCONTEXT:
397         /* Match if the low bits of mcontext/hcontext equal mhvalue. */
398         if (mhvalue != env->mcontext) {
399             return false;
400         }
401         break;
402     default:
403         break;
404     }
405 
406     return true;
407 }
408 
409 /* Common matching conditions for all types of the triggers. */
410 static bool trigger_common_match(CPURISCVState *env, trigger_type_t type,
411                                  int trigger_index)
412 {
413     return trigger_priv_match(env, type, trigger_index) &&
414            trigger_textra_match(env, type, trigger_index);
415 }
416 
417 /* type 2 trigger */
418 
419 static uint32_t type2_breakpoint_size(CPURISCVState *env, target_ulong ctrl)
420 {
421     uint32_t sizelo, sizehi = 0;
422 
423     if (riscv_cpu_mxl(env) == MXL_RV64) {
424         sizehi = extract32(ctrl, 21, 2);
425     }
426     sizelo = extract32(ctrl, 16, 2);
427     return (sizehi << 2) | sizelo;
428 }
429 
430 static inline bool type2_breakpoint_enabled(target_ulong ctrl)
431 {
432     bool mode = !!(ctrl & (TYPE2_U | TYPE2_S | TYPE2_M));
433     bool rwx = !!(ctrl & (TYPE2_LOAD | TYPE2_STORE | TYPE2_EXEC));
434 
435     return mode && rwx;
436 }
437 
438 static target_ulong type2_mcontrol_validate(CPURISCVState *env,
439                                             target_ulong ctrl)
440 {
441     target_ulong val;
442     uint32_t size;
443 
444     /* validate the generic part first */
445     val = tdata1_validate(env, ctrl, TRIGGER_TYPE_AD_MATCH);
446 
447     /* validate unimplemented (always zero) bits */
448     warn_always_zero_bit(ctrl, TYPE2_MATCH, "match");
449     warn_always_zero_bit(ctrl, TYPE2_CHAIN, "chain");
450     warn_always_zero_bit(ctrl, TYPE2_ACTION, "action");
451     warn_always_zero_bit(ctrl, TYPE2_TIMING, "timing");
452     warn_always_zero_bit(ctrl, TYPE2_SELECT, "select");
453     warn_always_zero_bit(ctrl, TYPE2_HIT, "hit");
454 
455     /* validate size encoding */
456     size = type2_breakpoint_size(env, ctrl);
457     if (access_size[size] == -1) {
458         qemu_log_mask(LOG_UNIMP, "access size %d is not supported, using "
459                                  "SIZE_ANY\n", size);
460     } else {
461         val |= (ctrl & TYPE2_SIZELO);
462         if (riscv_cpu_mxl(env) == MXL_RV64) {
463             val |= (ctrl & TYPE2_SIZEHI);
464         }
465     }
466 
467     /* keep the mode and attribute bits */
468     val |= (ctrl & (TYPE2_U | TYPE2_S | TYPE2_M |
469                     TYPE2_LOAD | TYPE2_STORE | TYPE2_EXEC));
470 
471     return val;
472 }
473 
474 static void type2_breakpoint_insert(CPURISCVState *env, target_ulong index)
475 {
476     target_ulong ctrl = env->tdata1[index];
477     target_ulong addr = env->tdata2[index];
478     bool enabled = type2_breakpoint_enabled(ctrl);
479     CPUState *cs = env_cpu(env);
480     int flags = BP_CPU | BP_STOP_BEFORE_ACCESS;
481     uint32_t size;
482 
483     if (!enabled) {
484         return;
485     }
486 
487     if (ctrl & TYPE2_EXEC) {
488         cpu_breakpoint_insert(cs, addr, flags, &env->cpu_breakpoint[index]);
489     }
490 
491     if (ctrl & TYPE2_LOAD) {
492         flags |= BP_MEM_READ;
493     }
494     if (ctrl & TYPE2_STORE) {
495         flags |= BP_MEM_WRITE;
496     }
497 
498     if (flags & BP_MEM_ACCESS) {
499         size = type2_breakpoint_size(env, ctrl);
500         if (size != 0) {
501             cpu_watchpoint_insert(cs, addr, size, flags,
502                                   &env->cpu_watchpoint[index]);
503         } else {
504             cpu_watchpoint_insert(cs, addr, 8, flags,
505                                   &env->cpu_watchpoint[index]);
506         }
507     }
508 }
509 
510 static void type2_breakpoint_remove(CPURISCVState *env, target_ulong index)
511 {
512     CPUState *cs = env_cpu(env);
513 
514     if (env->cpu_breakpoint[index]) {
515         cpu_breakpoint_remove_by_ref(cs, env->cpu_breakpoint[index]);
516         env->cpu_breakpoint[index] = NULL;
517     }
518 
519     if (env->cpu_watchpoint[index]) {
520         cpu_watchpoint_remove_by_ref(cs, env->cpu_watchpoint[index]);
521         env->cpu_watchpoint[index] = NULL;
522     }
523 }
524 
525 static void type2_reg_write(CPURISCVState *env, target_ulong index,
526                             int tdata_index, target_ulong val)
527 {
528     target_ulong new_val;
529 
530     switch (tdata_index) {
531     case TDATA1:
532         new_val = type2_mcontrol_validate(env, val);
533         if (new_val != env->tdata1[index]) {
534             env->tdata1[index] = new_val;
535             type2_breakpoint_remove(env, index);
536             type2_breakpoint_insert(env, index);
537         }
538         break;
539     case TDATA2:
540         if (val != env->tdata2[index]) {
541             env->tdata2[index] = val;
542             type2_breakpoint_remove(env, index);
543             type2_breakpoint_insert(env, index);
544         }
545         break;
546     case TDATA3:
547         env->tdata3[index] = textra_validate(env, val);
548         break;
549     default:
550         g_assert_not_reached();
551     }
552 
553     return;
554 }
555 
556 /* type 6 trigger */
557 
558 static inline bool type6_breakpoint_enabled(target_ulong ctrl)
559 {
560     bool mode = !!(ctrl & (TYPE6_VU | TYPE6_VS | TYPE6_U | TYPE6_S | TYPE6_M));
561     bool rwx = !!(ctrl & (TYPE6_LOAD | TYPE6_STORE | TYPE6_EXEC));
562 
563     return mode && rwx;
564 }
565 
566 static target_ulong type6_mcontrol6_validate(CPURISCVState *env,
567                                              target_ulong ctrl)
568 {
569     target_ulong val;
570     uint32_t size;
571 
572     /* validate the generic part first */
573     val = tdata1_validate(env, ctrl, TRIGGER_TYPE_AD_MATCH6);
574 
575     /* validate unimplemented (always zero) bits */
576     warn_always_zero_bit(ctrl, TYPE6_MATCH, "match");
577     warn_always_zero_bit(ctrl, TYPE6_CHAIN, "chain");
578     warn_always_zero_bit(ctrl, TYPE6_ACTION, "action");
579     warn_always_zero_bit(ctrl, TYPE6_TIMING, "timing");
580     warn_always_zero_bit(ctrl, TYPE6_SELECT, "select");
581     warn_always_zero_bit(ctrl, TYPE6_HIT, "hit");
582 
583     /* validate size encoding */
584     size = extract32(ctrl, 16, 4);
585     if (access_size[size] == -1) {
586         qemu_log_mask(LOG_UNIMP, "access size %d is not supported, using "
587                                  "SIZE_ANY\n", size);
588     } else {
589         val |= (ctrl & TYPE6_SIZE);
590     }
591 
592     /* keep the mode and attribute bits */
593     val |= (ctrl & (TYPE6_VU | TYPE6_VS | TYPE6_U | TYPE6_S | TYPE6_M |
594                     TYPE6_LOAD | TYPE6_STORE | TYPE6_EXEC));
595 
596     return val;
597 }
598 
599 static void type6_breakpoint_insert(CPURISCVState *env, target_ulong index)
600 {
601     target_ulong ctrl = env->tdata1[index];
602     target_ulong addr = env->tdata2[index];
603     bool enabled = type6_breakpoint_enabled(ctrl);
604     CPUState *cs = env_cpu(env);
605     int flags = BP_CPU | BP_STOP_BEFORE_ACCESS;
606     uint32_t size;
607 
608     if (!enabled) {
609         return;
610     }
611 
612     if (ctrl & TYPE6_EXEC) {
613         cpu_breakpoint_insert(cs, addr, flags, &env->cpu_breakpoint[index]);
614     }
615 
616     if (ctrl & TYPE6_LOAD) {
617         flags |= BP_MEM_READ;
618     }
619 
620     if (ctrl & TYPE6_STORE) {
621         flags |= BP_MEM_WRITE;
622     }
623 
624     if (flags & BP_MEM_ACCESS) {
625         size = extract32(ctrl, 16, 4);
626         if (size != 0) {
627             cpu_watchpoint_insert(cs, addr, size, flags,
628                                   &env->cpu_watchpoint[index]);
629         } else {
630             cpu_watchpoint_insert(cs, addr, 8, flags,
631                                   &env->cpu_watchpoint[index]);
632         }
633     }
634 }
635 
636 static void type6_breakpoint_remove(CPURISCVState *env, target_ulong index)
637 {
638     type2_breakpoint_remove(env, index);
639 }
640 
641 static void type6_reg_write(CPURISCVState *env, target_ulong index,
642                             int tdata_index, target_ulong val)
643 {
644     target_ulong new_val;
645 
646     switch (tdata_index) {
647     case TDATA1:
648         new_val = type6_mcontrol6_validate(env, val);
649         if (new_val != env->tdata1[index]) {
650             env->tdata1[index] = new_val;
651             type6_breakpoint_remove(env, index);
652             type6_breakpoint_insert(env, index);
653         }
654         break;
655     case TDATA2:
656         if (val != env->tdata2[index]) {
657             env->tdata2[index] = val;
658             type6_breakpoint_remove(env, index);
659             type6_breakpoint_insert(env, index);
660         }
661         break;
662     case TDATA3:
663         env->tdata3[index] = textra_validate(env, val);
664         break;
665     default:
666         g_assert_not_reached();
667     }
668 
669     return;
670 }
671 
672 /* icount trigger type */
673 static inline int
674 itrigger_get_count(CPURISCVState *env, int index)
675 {
676     return get_field(env->tdata1[index], ITRIGGER_COUNT);
677 }
678 
679 static inline void
680 itrigger_set_count(CPURISCVState *env, int index, int value)
681 {
682     env->tdata1[index] = set_field(env->tdata1[index],
683                                    ITRIGGER_COUNT, value);
684 }
685 
686 static bool check_itrigger_priv(CPURISCVState *env, int index)
687 {
688     target_ulong tdata1 = env->tdata1[index];
689     if (env->virt_enabled) {
690         /* check VU/VS bit against current privilege level */
691         return (get_field(tdata1, ITRIGGER_VS) == env->priv) ||
692                (get_field(tdata1, ITRIGGER_VU) == env->priv);
693     } else {
694         /* check U/S/M bit against current privilege level */
695         return (get_field(tdata1, ITRIGGER_M) == env->priv) ||
696                (get_field(tdata1, ITRIGGER_S) == env->priv) ||
697                (get_field(tdata1, ITRIGGER_U) == env->priv);
698     }
699 }
700 
701 bool riscv_itrigger_enabled(CPURISCVState *env)
702 {
703     int count;
704     for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
705         if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
706             continue;
707         }
708         if (check_itrigger_priv(env, i)) {
709             continue;
710         }
711         count = itrigger_get_count(env, i);
712         if (!count) {
713             continue;
714         }
715         return true;
716     }
717 
718     return false;
719 }
720 
721 void helper_itrigger_match(CPURISCVState *env)
722 {
723     int count;
724     for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
725         if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
726             continue;
727         }
728         if (!trigger_common_match(env, TRIGGER_TYPE_INST_CNT, i)) {
729             continue;
730         }
731         count = itrigger_get_count(env, i);
732         if (!count) {
733             continue;
734         }
735         itrigger_set_count(env, i, count--);
736         if (!count) {
737             env->itrigger_enabled = riscv_itrigger_enabled(env);
738             do_trigger_action(env, i);
739         }
740     }
741 }
742 
743 static void riscv_itrigger_update_count(CPURISCVState *env)
744 {
745     int count, executed;
746     /*
747      * Record last icount, so that we can evaluate the executed instructions
748      * since last privilege mode change or timer expire.
749      */
750     int64_t last_icount = env->last_icount, current_icount;
751     current_icount = env->last_icount = icount_get_raw();
752 
753     for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
754         if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
755             continue;
756         }
757         count = itrigger_get_count(env, i);
758         if (!count) {
759             continue;
760         }
761         /*
762          * Only when privilege is changed or itrigger timer expires,
763          * the count field in itrigger tdata1 register is updated.
764          * And the count field in itrigger only contains remaining value.
765          */
766         if (check_itrigger_priv(env, i)) {
767             /*
768              * If itrigger enabled in this privilege mode, the number of
769              * executed instructions since last privilege change
770              * should be reduced from current itrigger count.
771              */
772             executed = current_icount - last_icount;
773             itrigger_set_count(env, i, count - executed);
774             if (count == executed) {
775                 do_trigger_action(env, i);
776             }
777         } else {
778             /*
779              * If itrigger is not enabled in this privilege mode,
780              * the number of executed instructions will be discard and
781              * the count field in itrigger will not change.
782              */
783             timer_mod(env->itrigger_timer[i],
784                       current_icount + count);
785         }
786     }
787 }
788 
789 static void riscv_itrigger_timer_cb(void *opaque)
790 {
791     riscv_itrigger_update_count((CPURISCVState *)opaque);
792 }
793 
794 void riscv_itrigger_update_priv(CPURISCVState *env)
795 {
796     riscv_itrigger_update_count(env);
797 }
798 
799 static target_ulong itrigger_validate(CPURISCVState *env,
800                                       target_ulong ctrl)
801 {
802     target_ulong val;
803 
804     /* validate the generic part first */
805     val = tdata1_validate(env, ctrl, TRIGGER_TYPE_INST_CNT);
806 
807     /* validate unimplemented (always zero) bits */
808     warn_always_zero_bit(ctrl, ITRIGGER_ACTION, "action");
809     warn_always_zero_bit(ctrl, ITRIGGER_HIT, "hit");
810     warn_always_zero_bit(ctrl, ITRIGGER_PENDING, "pending");
811 
812     /* keep the mode and attribute bits */
813     val |= ctrl & (ITRIGGER_VU | ITRIGGER_VS | ITRIGGER_U | ITRIGGER_S |
814                    ITRIGGER_M | ITRIGGER_COUNT);
815 
816     return val;
817 }
818 
819 static void itrigger_reg_write(CPURISCVState *env, target_ulong index,
820                                int tdata_index, target_ulong val)
821 {
822     target_ulong new_val;
823 
824     switch (tdata_index) {
825     case TDATA1:
826         /* set timer for icount */
827         new_val = itrigger_validate(env, val);
828         if (new_val != env->tdata1[index]) {
829             env->tdata1[index] = new_val;
830             if (icount_enabled()) {
831                 env->last_icount = icount_get_raw();
832                 /* set the count to timer */
833                 timer_mod(env->itrigger_timer[index],
834                           env->last_icount + itrigger_get_count(env, index));
835             } else {
836                 env->itrigger_enabled = riscv_itrigger_enabled(env);
837             }
838         }
839         break;
840     case TDATA2:
841         qemu_log_mask(LOG_UNIMP,
842                       "tdata2 is not supported for icount trigger\n");
843         break;
844     case TDATA3:
845         env->tdata3[index] = textra_validate(env, val);
846         break;
847     default:
848         g_assert_not_reached();
849     }
850 
851     return;
852 }
853 
854 static int itrigger_get_adjust_count(CPURISCVState *env)
855 {
856     int count = itrigger_get_count(env, env->trigger_cur), executed;
857     if ((count != 0) && check_itrigger_priv(env, env->trigger_cur)) {
858         executed = icount_get_raw() - env->last_icount;
859         count += executed;
860     }
861     return count;
862 }
863 
864 target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index)
865 {
866     int trigger_type;
867     switch (tdata_index) {
868     case TDATA1:
869         trigger_type = extract_trigger_type(env,
870                                             env->tdata1[env->trigger_cur]);
871         if ((trigger_type == TRIGGER_TYPE_INST_CNT) && icount_enabled()) {
872             return deposit64(env->tdata1[env->trigger_cur], 10, 14,
873                              itrigger_get_adjust_count(env));
874         }
875         return env->tdata1[env->trigger_cur];
876     case TDATA2:
877         return env->tdata2[env->trigger_cur];
878     case TDATA3:
879         return env->tdata3[env->trigger_cur];
880     default:
881         g_assert_not_reached();
882     }
883 }
884 
885 void tdata_csr_write(CPURISCVState *env, int tdata_index, target_ulong val)
886 {
887     int trigger_type;
888 
889     if (tdata_index == TDATA1) {
890         trigger_type = extract_trigger_type(env, val);
891     } else {
892         trigger_type = get_trigger_type(env, env->trigger_cur);
893     }
894 
895     switch (trigger_type) {
896     case TRIGGER_TYPE_AD_MATCH:
897         type2_reg_write(env, env->trigger_cur, tdata_index, val);
898         break;
899     case TRIGGER_TYPE_AD_MATCH6:
900         type6_reg_write(env, env->trigger_cur, tdata_index, val);
901         break;
902     case TRIGGER_TYPE_INST_CNT:
903         itrigger_reg_write(env, env->trigger_cur, tdata_index, val);
904         break;
905     case TRIGGER_TYPE_INT:
906     case TRIGGER_TYPE_EXCP:
907     case TRIGGER_TYPE_EXT_SRC:
908         qemu_log_mask(LOG_UNIMP, "trigger type: %d is not supported\n",
909                       trigger_type);
910         break;
911     case TRIGGER_TYPE_NO_EXIST:
912     case TRIGGER_TYPE_UNAVAIL:
913         qemu_log_mask(LOG_GUEST_ERROR, "trigger type: %d does not exit\n",
914                       trigger_type);
915         break;
916     default:
917         g_assert_not_reached();
918     }
919 }
920 
921 target_ulong tinfo_csr_read(CPURISCVState *env)
922 {
923     /* assume all triggers support the same types of triggers */
924     return BIT(TRIGGER_TYPE_AD_MATCH) |
925            BIT(TRIGGER_TYPE_AD_MATCH6);
926 }
927 
928 void riscv_cpu_debug_excp_handler(CPUState *cs)
929 {
930     RISCVCPU *cpu = RISCV_CPU(cs);
931     CPURISCVState *env = &cpu->env;
932 
933     if (cs->watchpoint_hit) {
934         if (cs->watchpoint_hit->flags & BP_CPU) {
935             do_trigger_action(env, DBG_ACTION_BP);
936         }
937     } else {
938         if (cpu_breakpoint_test(cs, env->pc, BP_CPU)) {
939             do_trigger_action(env, DBG_ACTION_BP);
940         }
941     }
942 }
943 
944 bool riscv_cpu_debug_check_breakpoint(CPUState *cs)
945 {
946     RISCVCPU *cpu = RISCV_CPU(cs);
947     CPURISCVState *env = &cpu->env;
948     CPUBreakpoint *bp;
949     target_ulong ctrl;
950     target_ulong pc;
951     int trigger_type;
952     int i;
953 
954     QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
955         for (i = 0; i < RV_MAX_TRIGGERS; i++) {
956             trigger_type = get_trigger_type(env, i);
957 
958             if (!trigger_common_match(env, trigger_type, i)) {
959                 continue;
960             }
961 
962             switch (trigger_type) {
963             case TRIGGER_TYPE_AD_MATCH:
964                 ctrl = env->tdata1[i];
965                 pc = env->tdata2[i];
966 
967                 if ((ctrl & TYPE2_EXEC) && (bp->pc == pc)) {
968                     env->badaddr = pc;
969                     return true;
970                 }
971                 break;
972             case TRIGGER_TYPE_AD_MATCH6:
973                 ctrl = env->tdata1[i];
974                 pc = env->tdata2[i];
975 
976                 if ((ctrl & TYPE6_EXEC) && (bp->pc == pc)) {
977                     env->badaddr = pc;
978                     return true;
979                 }
980                 break;
981             default:
982                 /* other trigger types are not supported or irrelevant */
983                 break;
984             }
985         }
986     }
987 
988     return false;
989 }
990 
991 bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp)
992 {
993     RISCVCPU *cpu = RISCV_CPU(cs);
994     CPURISCVState *env = &cpu->env;
995     target_ulong ctrl;
996     target_ulong addr;
997     int trigger_type;
998     int flags;
999     int i;
1000 
1001     for (i = 0; i < RV_MAX_TRIGGERS; i++) {
1002         trigger_type = get_trigger_type(env, i);
1003 
1004         if (!trigger_common_match(env, trigger_type, i)) {
1005             continue;
1006         }
1007 
1008         switch (trigger_type) {
1009         case TRIGGER_TYPE_AD_MATCH:
1010             ctrl = env->tdata1[i];
1011             addr = env->tdata2[i];
1012             flags = 0;
1013 
1014             if (ctrl & TYPE2_LOAD) {
1015                 flags |= BP_MEM_READ;
1016             }
1017             if (ctrl & TYPE2_STORE) {
1018                 flags |= BP_MEM_WRITE;
1019             }
1020 
1021             if ((wp->flags & flags) && (wp->vaddr == addr)) {
1022                 return true;
1023             }
1024             break;
1025         case TRIGGER_TYPE_AD_MATCH6:
1026             ctrl = env->tdata1[i];
1027             addr = env->tdata2[i];
1028             flags = 0;
1029 
1030             if (ctrl & TYPE6_LOAD) {
1031                 flags |= BP_MEM_READ;
1032             }
1033             if (ctrl & TYPE6_STORE) {
1034                 flags |= BP_MEM_WRITE;
1035             }
1036 
1037             if ((wp->flags & flags) && (wp->vaddr == addr)) {
1038                 return true;
1039             }
1040             break;
1041         default:
1042             /* other trigger types are not supported */
1043             break;
1044         }
1045     }
1046 
1047     return false;
1048 }
1049 
1050 void riscv_trigger_realize(CPURISCVState *env)
1051 {
1052     int i;
1053 
1054     for (i = 0; i < RV_MAX_TRIGGERS; i++) {
1055         env->itrigger_timer[i] = timer_new_ns(QEMU_CLOCK_VIRTUAL,
1056                                               riscv_itrigger_timer_cb, env);
1057     }
1058 }
1059 
1060 void riscv_trigger_reset_hold(CPURISCVState *env)
1061 {
1062     target_ulong tdata1 = build_tdata1(env, TRIGGER_TYPE_AD_MATCH, 0, 0);
1063     int i;
1064 
1065     /* init to type 2 triggers */
1066     for (i = 0; i < RV_MAX_TRIGGERS; i++) {
1067         /*
1068          * type = TRIGGER_TYPE_AD_MATCH
1069          * dmode = 0 (both debug and M-mode can write tdata)
1070          * maskmax = 0 (unimplemented, always 0)
1071          * sizehi = 0 (match against any size, RV64 only)
1072          * hit = 0 (unimplemented, always 0)
1073          * select = 0 (always 0, perform match on address)
1074          * timing = 0 (always 0, trigger before instruction)
1075          * sizelo = 0 (match against any size)
1076          * action = 0 (always 0, raise a breakpoint exception)
1077          * chain = 0 (unimplemented, always 0)
1078          * match = 0 (always 0, when any compare value equals tdata2)
1079          */
1080         env->tdata1[i] = tdata1;
1081         env->tdata2[i] = 0;
1082         env->tdata3[i] = 0;
1083         env->cpu_breakpoint[i] = NULL;
1084         env->cpu_watchpoint[i] = NULL;
1085         timer_del(env->itrigger_timer[i]);
1086     }
1087 
1088     env->mcontext = 0;
1089 }
1090