xref: /openbmc/qemu/target/riscv/debug.c (revision 1408266d1c6aa0e197fede7781c090db0502f5ca)
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 
extract_trigger_type(CPURISCVState * env,target_ulong tdata1)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 
get_trigger_type(CPURISCVState * env,target_ulong trigger_index)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 
get_trigger_action(CPURISCVState * env,target_ulong trigger_index)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 
build_tdata1(CPURISCVState * env,trigger_type_t type,bool dmode,target_ulong data)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 
tdata_available(CPURISCVState * env,int tdata_index)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 
tselect_csr_read(CPURISCVState * env)166 target_ulong tselect_csr_read(CPURISCVState *env)
167 {
168     return env->trigger_cur;
169 }
170 
tselect_csr_write(CPURISCVState * env,target_ulong val)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 
tdata1_validate(CPURISCVState * env,target_ulong val,trigger_type_t t)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 
warn_always_zero_bit(target_ulong val,target_ulong mask,const char * msg)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 
textra_validate(CPURISCVState * env,target_ulong tdata3)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 
do_trigger_action(CPURISCVState * env,target_ulong trigger_index)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  */
trigger_priv_match(CPURISCVState * env,trigger_type_t type,int trigger_index)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 
trigger_textra_match(CPURISCVState * env,trigger_type_t type,int trigger_index)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. */
trigger_common_match(CPURISCVState * env,trigger_type_t type,int trigger_index)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 
type2_breakpoint_size(CPURISCVState * env,target_ulong ctrl)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 
type2_breakpoint_enabled(target_ulong ctrl)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 
type2_mcontrol_validate(CPURISCVState * env,target_ulong ctrl)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 
type2_breakpoint_insert(CPURISCVState * env,target_ulong index)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, def_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             def_size = riscv_cpu_mxl(env) == MXL_RV64 ? 8 : 4;
505 
506             cpu_watchpoint_insert(cs, addr, def_size, flags,
507                                   &env->cpu_watchpoint[index]);
508         }
509     }
510 }
511 
type2_breakpoint_remove(CPURISCVState * env,target_ulong index)512 static void type2_breakpoint_remove(CPURISCVState *env, target_ulong index)
513 {
514     CPUState *cs = env_cpu(env);
515 
516     if (env->cpu_breakpoint[index]) {
517         cpu_breakpoint_remove_by_ref(cs, env->cpu_breakpoint[index]);
518         env->cpu_breakpoint[index] = NULL;
519     }
520 
521     if (env->cpu_watchpoint[index]) {
522         cpu_watchpoint_remove_by_ref(cs, env->cpu_watchpoint[index]);
523         env->cpu_watchpoint[index] = NULL;
524     }
525 }
526 
type2_reg_write(CPURISCVState * env,target_ulong index,int tdata_index,target_ulong val)527 static void type2_reg_write(CPURISCVState *env, target_ulong index,
528                             int tdata_index, target_ulong val)
529 {
530     target_ulong new_val;
531 
532     switch (tdata_index) {
533     case TDATA1:
534         new_val = type2_mcontrol_validate(env, val);
535         if (new_val != env->tdata1[index]) {
536             env->tdata1[index] = new_val;
537             type2_breakpoint_remove(env, index);
538             type2_breakpoint_insert(env, index);
539         }
540         break;
541     case TDATA2:
542         if (val != env->tdata2[index]) {
543             env->tdata2[index] = val;
544             type2_breakpoint_remove(env, index);
545             type2_breakpoint_insert(env, index);
546         }
547         break;
548     case TDATA3:
549         env->tdata3[index] = textra_validate(env, val);
550         break;
551     default:
552         g_assert_not_reached();
553     }
554 
555     return;
556 }
557 
558 /* type 6 trigger */
559 
type6_breakpoint_enabled(target_ulong ctrl)560 static inline bool type6_breakpoint_enabled(target_ulong ctrl)
561 {
562     bool mode = !!(ctrl & (TYPE6_VU | TYPE6_VS | TYPE6_U | TYPE6_S | TYPE6_M));
563     bool rwx = !!(ctrl & (TYPE6_LOAD | TYPE6_STORE | TYPE6_EXEC));
564 
565     return mode && rwx;
566 }
567 
type6_mcontrol6_validate(CPURISCVState * env,target_ulong ctrl)568 static target_ulong type6_mcontrol6_validate(CPURISCVState *env,
569                                              target_ulong ctrl)
570 {
571     target_ulong val;
572     uint32_t size;
573 
574     /* validate the generic part first */
575     val = tdata1_validate(env, ctrl, TRIGGER_TYPE_AD_MATCH6);
576 
577     /* validate unimplemented (always zero) bits */
578     warn_always_zero_bit(ctrl, TYPE6_MATCH, "match");
579     warn_always_zero_bit(ctrl, TYPE6_CHAIN, "chain");
580     warn_always_zero_bit(ctrl, TYPE6_ACTION, "action");
581     warn_always_zero_bit(ctrl, TYPE6_TIMING, "timing");
582     warn_always_zero_bit(ctrl, TYPE6_SELECT, "select");
583     warn_always_zero_bit(ctrl, TYPE6_HIT, "hit");
584 
585     /* validate size encoding */
586     size = extract32(ctrl, 16, 4);
587     if (access_size[size] == -1) {
588         qemu_log_mask(LOG_UNIMP, "access size %d is not supported, using "
589                                  "SIZE_ANY\n", size);
590     } else {
591         val |= (ctrl & TYPE6_SIZE);
592     }
593 
594     /* keep the mode and attribute bits */
595     val |= (ctrl & (TYPE6_VU | TYPE6_VS | TYPE6_U | TYPE6_S | TYPE6_M |
596                     TYPE6_LOAD | TYPE6_STORE | TYPE6_EXEC));
597 
598     return val;
599 }
600 
type6_breakpoint_insert(CPURISCVState * env,target_ulong index)601 static void type6_breakpoint_insert(CPURISCVState *env, target_ulong index)
602 {
603     target_ulong ctrl = env->tdata1[index];
604     target_ulong addr = env->tdata2[index];
605     bool enabled = type6_breakpoint_enabled(ctrl);
606     CPUState *cs = env_cpu(env);
607     int flags = BP_CPU | BP_STOP_BEFORE_ACCESS;
608     uint32_t size;
609 
610     if (!enabled) {
611         return;
612     }
613 
614     if (ctrl & TYPE6_EXEC) {
615         cpu_breakpoint_insert(cs, addr, flags, &env->cpu_breakpoint[index]);
616     }
617 
618     if (ctrl & TYPE6_LOAD) {
619         flags |= BP_MEM_READ;
620     }
621 
622     if (ctrl & TYPE6_STORE) {
623         flags |= BP_MEM_WRITE;
624     }
625 
626     if (flags & BP_MEM_ACCESS) {
627         size = extract32(ctrl, 16, 4);
628         if (size != 0) {
629             cpu_watchpoint_insert(cs, addr, size, flags,
630                                   &env->cpu_watchpoint[index]);
631         } else {
632             cpu_watchpoint_insert(cs, addr, 8, flags,
633                                   &env->cpu_watchpoint[index]);
634         }
635     }
636 }
637 
type6_breakpoint_remove(CPURISCVState * env,target_ulong index)638 static void type6_breakpoint_remove(CPURISCVState *env, target_ulong index)
639 {
640     type2_breakpoint_remove(env, index);
641 }
642 
type6_reg_write(CPURISCVState * env,target_ulong index,int tdata_index,target_ulong val)643 static void type6_reg_write(CPURISCVState *env, target_ulong index,
644                             int tdata_index, target_ulong val)
645 {
646     target_ulong new_val;
647 
648     switch (tdata_index) {
649     case TDATA1:
650         new_val = type6_mcontrol6_validate(env, val);
651         if (new_val != env->tdata1[index]) {
652             env->tdata1[index] = new_val;
653             type6_breakpoint_remove(env, index);
654             type6_breakpoint_insert(env, index);
655         }
656         break;
657     case TDATA2:
658         if (val != env->tdata2[index]) {
659             env->tdata2[index] = val;
660             type6_breakpoint_remove(env, index);
661             type6_breakpoint_insert(env, index);
662         }
663         break;
664     case TDATA3:
665         env->tdata3[index] = textra_validate(env, val);
666         break;
667     default:
668         g_assert_not_reached();
669     }
670 
671     return;
672 }
673 
674 /* icount trigger type */
675 static inline int
itrigger_get_count(CPURISCVState * env,int index)676 itrigger_get_count(CPURISCVState *env, int index)
677 {
678     return get_field(env->tdata1[index], ITRIGGER_COUNT);
679 }
680 
681 static inline void
itrigger_set_count(CPURISCVState * env,int index,int value)682 itrigger_set_count(CPURISCVState *env, int index, int value)
683 {
684     env->tdata1[index] = set_field(env->tdata1[index],
685                                    ITRIGGER_COUNT, value);
686 }
687 
check_itrigger_priv(CPURISCVState * env,int index)688 static bool check_itrigger_priv(CPURISCVState *env, int index)
689 {
690     target_ulong tdata1 = env->tdata1[index];
691     if (env->virt_enabled) {
692         /* check VU/VS bit against current privilege level */
693         return (get_field(tdata1, ITRIGGER_VS) == env->priv) ||
694                (get_field(tdata1, ITRIGGER_VU) == env->priv);
695     } else {
696         /* check U/S/M bit against current privilege level */
697         return (get_field(tdata1, ITRIGGER_M) == env->priv) ||
698                (get_field(tdata1, ITRIGGER_S) == env->priv) ||
699                (get_field(tdata1, ITRIGGER_U) == env->priv);
700     }
701 }
702 
riscv_itrigger_enabled(CPURISCVState * env)703 bool riscv_itrigger_enabled(CPURISCVState *env)
704 {
705     int count;
706     for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
707         if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
708             continue;
709         }
710         if (check_itrigger_priv(env, i)) {
711             continue;
712         }
713         count = itrigger_get_count(env, i);
714         if (!count) {
715             continue;
716         }
717         return true;
718     }
719 
720     return false;
721 }
722 
helper_itrigger_match(CPURISCVState * env)723 void helper_itrigger_match(CPURISCVState *env)
724 {
725     int count;
726     for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
727         if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
728             continue;
729         }
730         if (!trigger_common_match(env, TRIGGER_TYPE_INST_CNT, i)) {
731             continue;
732         }
733         count = itrigger_get_count(env, i);
734         if (!count) {
735             continue;
736         }
737         itrigger_set_count(env, i, count--);
738         if (!count) {
739             env->itrigger_enabled = riscv_itrigger_enabled(env);
740             do_trigger_action(env, i);
741         }
742     }
743 }
744 
riscv_itrigger_update_count(CPURISCVState * env)745 static void riscv_itrigger_update_count(CPURISCVState *env)
746 {
747     int count, executed;
748     /*
749      * Record last icount, so that we can evaluate the executed instructions
750      * since last privilege mode change or timer expire.
751      */
752     int64_t last_icount = env->last_icount, current_icount;
753     current_icount = env->last_icount = icount_get_raw();
754 
755     for (int i = 0; i < RV_MAX_TRIGGERS; i++) {
756         if (get_trigger_type(env, i) != TRIGGER_TYPE_INST_CNT) {
757             continue;
758         }
759         count = itrigger_get_count(env, i);
760         if (!count) {
761             continue;
762         }
763         /*
764          * Only when privilege is changed or itrigger timer expires,
765          * the count field in itrigger tdata1 register is updated.
766          * And the count field in itrigger only contains remaining value.
767          */
768         if (check_itrigger_priv(env, i)) {
769             /*
770              * If itrigger enabled in this privilege mode, the number of
771              * executed instructions since last privilege change
772              * should be reduced from current itrigger count.
773              */
774             executed = current_icount - last_icount;
775             itrigger_set_count(env, i, count - executed);
776             if (count == executed) {
777                 do_trigger_action(env, i);
778             }
779         } else {
780             /*
781              * If itrigger is not enabled in this privilege mode,
782              * the number of executed instructions will be discard and
783              * the count field in itrigger will not change.
784              */
785             timer_mod(env->itrigger_timer[i],
786                       current_icount + count);
787         }
788     }
789 }
790 
riscv_itrigger_timer_cb(void * opaque)791 static void riscv_itrigger_timer_cb(void *opaque)
792 {
793     riscv_itrigger_update_count((CPURISCVState *)opaque);
794 }
795 
riscv_itrigger_update_priv(CPURISCVState * env)796 void riscv_itrigger_update_priv(CPURISCVState *env)
797 {
798     riscv_itrigger_update_count(env);
799 }
800 
itrigger_validate(CPURISCVState * env,target_ulong ctrl)801 static target_ulong itrigger_validate(CPURISCVState *env,
802                                       target_ulong ctrl)
803 {
804     target_ulong val;
805 
806     /* validate the generic part first */
807     val = tdata1_validate(env, ctrl, TRIGGER_TYPE_INST_CNT);
808 
809     /* validate unimplemented (always zero) bits */
810     warn_always_zero_bit(ctrl, ITRIGGER_ACTION, "action");
811     warn_always_zero_bit(ctrl, ITRIGGER_HIT, "hit");
812     warn_always_zero_bit(ctrl, ITRIGGER_PENDING, "pending");
813 
814     /* keep the mode and attribute bits */
815     val |= ctrl & (ITRIGGER_VU | ITRIGGER_VS | ITRIGGER_U | ITRIGGER_S |
816                    ITRIGGER_M | ITRIGGER_COUNT);
817 
818     return val;
819 }
820 
itrigger_reg_write(CPURISCVState * env,target_ulong index,int tdata_index,target_ulong val)821 static void itrigger_reg_write(CPURISCVState *env, target_ulong index,
822                                int tdata_index, target_ulong val)
823 {
824     target_ulong new_val;
825 
826     switch (tdata_index) {
827     case TDATA1:
828         /* set timer for icount */
829         new_val = itrigger_validate(env, val);
830         if (new_val != env->tdata1[index]) {
831             env->tdata1[index] = new_val;
832             if (icount_enabled()) {
833                 env->last_icount = icount_get_raw();
834                 /* set the count to timer */
835                 timer_mod(env->itrigger_timer[index],
836                           env->last_icount + itrigger_get_count(env, index));
837             } else {
838                 env->itrigger_enabled = riscv_itrigger_enabled(env);
839             }
840         }
841         break;
842     case TDATA2:
843         qemu_log_mask(LOG_UNIMP,
844                       "tdata2 is not supported for icount trigger\n");
845         break;
846     case TDATA3:
847         env->tdata3[index] = textra_validate(env, val);
848         break;
849     default:
850         g_assert_not_reached();
851     }
852 
853     return;
854 }
855 
itrigger_get_adjust_count(CPURISCVState * env)856 static int itrigger_get_adjust_count(CPURISCVState *env)
857 {
858     int count = itrigger_get_count(env, env->trigger_cur), executed;
859     if ((count != 0) && check_itrigger_priv(env, env->trigger_cur)) {
860         executed = icount_get_raw() - env->last_icount;
861         count += executed;
862     }
863     return count;
864 }
865 
tdata_csr_read(CPURISCVState * env,int tdata_index)866 target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index)
867 {
868     int trigger_type;
869     switch (tdata_index) {
870     case TDATA1:
871         trigger_type = extract_trigger_type(env,
872                                             env->tdata1[env->trigger_cur]);
873         if ((trigger_type == TRIGGER_TYPE_INST_CNT) && icount_enabled()) {
874             return deposit64(env->tdata1[env->trigger_cur], 10, 14,
875                              itrigger_get_adjust_count(env));
876         }
877         return env->tdata1[env->trigger_cur];
878     case TDATA2:
879         return env->tdata2[env->trigger_cur];
880     case TDATA3:
881         return env->tdata3[env->trigger_cur];
882     default:
883         g_assert_not_reached();
884     }
885 }
886 
tdata_csr_write(CPURISCVState * env,int tdata_index,target_ulong val)887 void tdata_csr_write(CPURISCVState *env, int tdata_index, target_ulong val)
888 {
889     int trigger_type;
890 
891     if (tdata_index == TDATA1) {
892         trigger_type = extract_trigger_type(env, val);
893     } else {
894         trigger_type = get_trigger_type(env, env->trigger_cur);
895     }
896 
897     switch (trigger_type) {
898     case TRIGGER_TYPE_AD_MATCH:
899         type2_reg_write(env, env->trigger_cur, tdata_index, val);
900         break;
901     case TRIGGER_TYPE_AD_MATCH6:
902         type6_reg_write(env, env->trigger_cur, tdata_index, val);
903         break;
904     case TRIGGER_TYPE_INST_CNT:
905         itrigger_reg_write(env, env->trigger_cur, tdata_index, val);
906         break;
907     case TRIGGER_TYPE_INT:
908     case TRIGGER_TYPE_EXCP:
909     case TRIGGER_TYPE_EXT_SRC:
910         qemu_log_mask(LOG_UNIMP, "trigger type: %d is not supported\n",
911                       trigger_type);
912         break;
913     case TRIGGER_TYPE_NO_EXIST:
914     case TRIGGER_TYPE_UNAVAIL:
915         qemu_log_mask(LOG_GUEST_ERROR, "trigger type: %d does not exit\n",
916                       trigger_type);
917         break;
918     default:
919         g_assert_not_reached();
920     }
921 }
922 
tinfo_csr_read(CPURISCVState * env)923 target_ulong tinfo_csr_read(CPURISCVState *env)
924 {
925     /* assume all triggers support the same types of triggers */
926     return BIT(TRIGGER_TYPE_AD_MATCH) |
927            BIT(TRIGGER_TYPE_AD_MATCH6);
928 }
929 
riscv_cpu_debug_excp_handler(CPUState * cs)930 void riscv_cpu_debug_excp_handler(CPUState *cs)
931 {
932     RISCVCPU *cpu = RISCV_CPU(cs);
933     CPURISCVState *env = &cpu->env;
934 
935     if (cs->watchpoint_hit) {
936         if (cs->watchpoint_hit->flags & BP_CPU) {
937             do_trigger_action(env, DBG_ACTION_BP);
938         }
939     } else {
940         if (cpu_breakpoint_test(cs, env->pc, BP_CPU)) {
941             do_trigger_action(env, DBG_ACTION_BP);
942         }
943     }
944 }
945 
riscv_cpu_debug_check_breakpoint(CPUState * cs)946 bool riscv_cpu_debug_check_breakpoint(CPUState *cs)
947 {
948     RISCVCPU *cpu = RISCV_CPU(cs);
949     CPURISCVState *env = &cpu->env;
950     CPUBreakpoint *bp;
951     target_ulong ctrl;
952     target_ulong pc;
953     int trigger_type;
954     int i;
955 
956     QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
957         for (i = 0; i < RV_MAX_TRIGGERS; i++) {
958             trigger_type = get_trigger_type(env, i);
959 
960             if (!trigger_common_match(env, trigger_type, i)) {
961                 continue;
962             }
963 
964             switch (trigger_type) {
965             case TRIGGER_TYPE_AD_MATCH:
966                 ctrl = env->tdata1[i];
967                 pc = env->tdata2[i];
968 
969                 if ((ctrl & TYPE2_EXEC) && (bp->pc == pc)) {
970                     env->badaddr = pc;
971                     return true;
972                 }
973                 break;
974             case TRIGGER_TYPE_AD_MATCH6:
975                 ctrl = env->tdata1[i];
976                 pc = env->tdata2[i];
977 
978                 if ((ctrl & TYPE6_EXEC) && (bp->pc == pc)) {
979                     env->badaddr = pc;
980                     return true;
981                 }
982                 break;
983             default:
984                 /* other trigger types are not supported or irrelevant */
985                 break;
986             }
987         }
988     }
989 
990     return false;
991 }
992 
riscv_cpu_debug_check_watchpoint(CPUState * cs,CPUWatchpoint * wp)993 bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp)
994 {
995     RISCVCPU *cpu = RISCV_CPU(cs);
996     CPURISCVState *env = &cpu->env;
997     target_ulong ctrl;
998     target_ulong addr;
999     int trigger_type;
1000     int flags;
1001     int i;
1002 
1003     for (i = 0; i < RV_MAX_TRIGGERS; i++) {
1004         trigger_type = get_trigger_type(env, i);
1005 
1006         if (!trigger_common_match(env, trigger_type, i)) {
1007             continue;
1008         }
1009 
1010         switch (trigger_type) {
1011         case TRIGGER_TYPE_AD_MATCH:
1012             ctrl = env->tdata1[i];
1013             addr = env->tdata2[i];
1014             flags = 0;
1015 
1016             if (ctrl & TYPE2_LOAD) {
1017                 flags |= BP_MEM_READ;
1018             }
1019             if (ctrl & TYPE2_STORE) {
1020                 flags |= BP_MEM_WRITE;
1021             }
1022 
1023             if ((wp->flags & flags) && (wp->vaddr == addr)) {
1024                 return true;
1025             }
1026             break;
1027         case TRIGGER_TYPE_AD_MATCH6:
1028             ctrl = env->tdata1[i];
1029             addr = env->tdata2[i];
1030             flags = 0;
1031 
1032             if (ctrl & TYPE6_LOAD) {
1033                 flags |= BP_MEM_READ;
1034             }
1035             if (ctrl & TYPE6_STORE) {
1036                 flags |= BP_MEM_WRITE;
1037             }
1038 
1039             if ((wp->flags & flags) && (wp->vaddr == addr)) {
1040                 return true;
1041             }
1042             break;
1043         default:
1044             /* other trigger types are not supported */
1045             break;
1046         }
1047     }
1048 
1049     return false;
1050 }
1051 
riscv_trigger_realize(CPURISCVState * env)1052 void riscv_trigger_realize(CPURISCVState *env)
1053 {
1054     int i;
1055 
1056     for (i = 0; i < RV_MAX_TRIGGERS; i++) {
1057         env->itrigger_timer[i] = timer_new_ns(QEMU_CLOCK_VIRTUAL,
1058                                               riscv_itrigger_timer_cb, env);
1059     }
1060 }
1061 
riscv_trigger_reset_hold(CPURISCVState * env)1062 void riscv_trigger_reset_hold(CPURISCVState *env)
1063 {
1064     target_ulong tdata1 = build_tdata1(env, TRIGGER_TYPE_AD_MATCH, 0, 0);
1065     int i;
1066 
1067     /* init to type 2 triggers */
1068     for (i = 0; i < RV_MAX_TRIGGERS; i++) {
1069         /*
1070          * type = TRIGGER_TYPE_AD_MATCH
1071          * dmode = 0 (both debug and M-mode can write tdata)
1072          * maskmax = 0 (unimplemented, always 0)
1073          * sizehi = 0 (match against any size, RV64 only)
1074          * hit = 0 (unimplemented, always 0)
1075          * select = 0 (always 0, perform match on address)
1076          * timing = 0 (always 0, trigger before instruction)
1077          * sizelo = 0 (match against any size)
1078          * action = 0 (always 0, raise a breakpoint exception)
1079          * chain = 0 (unimplemented, always 0)
1080          * match = 0 (always 0, when any compare value equals tdata2)
1081          */
1082         env->tdata1[i] = tdata1;
1083         env->tdata2[i] = 0;
1084         env->tdata3[i] = 0;
1085         env->cpu_breakpoint[i] = NULL;
1086         env->cpu_watchpoint[i] = NULL;
1087         timer_del(env->itrigger_timer[i]);
1088     }
1089 
1090     env->mcontext = 0;
1091 }
1092