1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
|
/*
* RISC-V CPU helpers for qemu.
*
* Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
* Copyright (c) 2017-2018 SiFive, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "qemu/main-loop.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "tcg/tcg-op.h"
#include "trace.h"
#include "semihosting/common-semi.h"
int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
{
#ifdef CONFIG_USER_ONLY
return 0;
#else
return env->priv;
#endif
}
void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
target_ulong *cs_base, uint32_t *pflags)
{
uint32_t flags = 0;
*pc = env->pc;
*cs_base = 0;
if (riscv_has_ext(env, RVV)) {
uint32_t vlmax = vext_get_vlmax(env_archcpu(env), env->vtype);
bool vl_eq_vlmax = (env->vstart == 0) && (vlmax == env->vl);
flags = FIELD_DP32(flags, TB_FLAGS, VILL,
FIELD_EX64(env->vtype, VTYPE, VILL));
flags = FIELD_DP32(flags, TB_FLAGS, SEW,
FIELD_EX64(env->vtype, VTYPE, VSEW));
flags = FIELD_DP32(flags, TB_FLAGS, LMUL,
FIELD_EX64(env->vtype, VTYPE, VLMUL));
flags = FIELD_DP32(flags, TB_FLAGS, VL_EQ_VLMAX, vl_eq_vlmax);
} else {
flags = FIELD_DP32(flags, TB_FLAGS, VILL, 1);
}
#ifdef CONFIG_USER_ONLY
flags |= TB_FLAGS_MSTATUS_FS;
#else
flags |= cpu_mmu_index(env, 0);
if (riscv_cpu_fp_enabled(env)) {
flags |= env->mstatus & MSTATUS_FS;
}
if (riscv_has_ext(env, RVH)) {
if (env->priv == PRV_M ||
(env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) ||
(env->priv == PRV_U && !riscv_cpu_virt_enabled(env) &&
get_field(env->hstatus, HSTATUS_HU))) {
flags = FIELD_DP32(flags, TB_FLAGS, HLSX, 1);
}
flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_FS,
get_field(env->mstatus_hs, MSTATUS_FS));
}
#endif
*pflags = flags;
}
#ifndef CONFIG_USER_ONLY
static int riscv_cpu_local_irq_pending(CPURISCVState *env)
{
target_ulong irqs;
target_ulong mstatus_mie = get_field(env->mstatus, MSTATUS_MIE);
target_ulong mstatus_sie = get_field(env->mstatus, MSTATUS_SIE);
target_ulong hs_mstatus_sie = get_field(env->mstatus_hs, MSTATUS_SIE);
target_ulong pending = env->mip & env->mie &
~(MIP_VSSIP | MIP_VSTIP | MIP_VSEIP);
target_ulong vspending = (env->mip & env->mie &
(MIP_VSSIP | MIP_VSTIP | MIP_VSEIP));
target_ulong mie = env->priv < PRV_M ||
(env->priv == PRV_M && mstatus_mie);
target_ulong sie = env->priv < PRV_S ||
(env->priv == PRV_S && mstatus_sie);
target_ulong hs_sie = env->priv < PRV_S ||
(env->priv == PRV_S && hs_mstatus_sie);
if (riscv_cpu_virt_enabled(env)) {
target_ulong pending_hs_irq = pending & -hs_sie;
if (pending_hs_irq) {
riscv_cpu_set_force_hs_excep(env, FORCE_HS_EXCEP);
return ctz64(pending_hs_irq);
}
pending = vspending;
}
irqs = (pending & ~env->mideleg & -mie) | (pending & env->mideleg & -sie);
if (irqs) {
return ctz64(irqs); /* since non-zero */
} else {
return RISCV_EXCP_NONE; /* indicates no pending interrupt */
}
}
bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
{
if (interrupt_request & CPU_INTERRUPT_HARD) {
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
int interruptno = riscv_cpu_local_irq_pending(env);
if (interruptno >= 0) {
cs->exception_index = RISCV_EXCP_INT_FLAG | interruptno;
riscv_cpu_do_interrupt(cs);
return true;
}
}
return false;
}
/* Return true is floating point support is currently enabled */
bool riscv_cpu_fp_enabled(CPURISCVState *env)
{
if (env->mstatus & MSTATUS_FS) {
if (riscv_cpu_virt_enabled(env) && !(env->mstatus_hs & MSTATUS_FS)) {
return false;
}
return true;
}
return false;
}
void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
{
uint64_t sd = riscv_cpu_is_32bit(env) ? MSTATUS32_SD : MSTATUS64_SD;
uint64_t mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE |
MSTATUS64_UXL | sd;
bool current_virt = riscv_cpu_virt_enabled(env);
g_assert(riscv_has_ext(env, RVH));
if (current_virt) {
/* Current V=1 and we are about to change to V=0 */
env->vsstatus = env->mstatus & mstatus_mask;
env->mstatus &= ~mstatus_mask;
env->mstatus |= env->mstatus_hs;
env->vstvec = env->stvec;
env->stvec = env->stvec_hs;
env->vsscratch = env->sscratch;
env->sscratch = env->sscratch_hs;
env->vsepc = env->sepc;
env->sepc = env->sepc_hs;
env->vscause = env->scause;
env->scause = env->scause_hs;
env->vstval = env->stval;
env->stval = env->stval_hs;
env->vsatp = env->satp;
env->satp = env->satp_hs;
} else {
/* Current V=0 and we are about to change to V=1 */
env->mstatus_hs = env->mstatus & mstatus_mask;
env->mstatus &= ~mstatus_mask;
env->mstatus |= env->vsstatus;
env->stvec_hs = env->stvec;
env->stvec = env->vstvec;
env->sscratch_hs = env->sscratch;
env->sscratch = env->vsscratch;
env->sepc_hs = env->sepc;
env->sepc = env->vsepc;
env->scause_hs = env->scause;
env->scause = env->vscause;
env->stval_hs = env->stval;
env->stval = env->vstval;
env->satp_hs = env->satp;
env->satp = env->vsatp;
}
}
bool riscv_cpu_virt_enabled(CPURISCVState *env)
{
if (!riscv_has_ext(env, RVH)) {
return false;
}
return get_field(env->virt, VIRT_ONOFF);
}
void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
{
if (!riscv_has_ext(env, RVH)) {
return;
}
/* Flush the TLB on all virt mode changes. */
if (get_field(env->virt, VIRT_ONOFF) != enable) {
tlb_flush(env_cpu(env));
}
env->virt = set_field(env->virt, VIRT_ONOFF, enable);
}
bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env)
{
if (!riscv_has_ext(env, RVH)) {
return false;
}
return get_field(env->virt, FORCE_HS_EXCEP);
}
void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable)
{
if (!riscv_has_ext(env, RVH)) {
return;
}
env->virt = set_field(env->virt, FORCE_HS_EXCEP, enable);
}
bool riscv_cpu_two_stage_lookup(int mmu_idx)
{
return mmu_idx & TB_FLAGS_PRIV_HYP_ACCESS_MASK;
}
int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
{
CPURISCVState *env = &cpu->env;
if (env->miclaim & interrupts) {
return -1;
} else {
env->miclaim |= interrupts;
return 0;
}
}
uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value)
{
CPURISCVState *env = &cpu->env;
CPUState *cs = CPU(cpu);
uint32_t old = env->mip;
bool locked = false;
if (!qemu_mutex_iothread_locked()) {
locked = true;
qemu_mutex_lock_iothread();
}
env->mip = (env->mip & ~mask) | (value & mask);
if (env->mip) {
cpu_interrupt(cs, CPU_INTERRUPT_HARD);
} else {
cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
}
if (locked) {
qemu_mutex_unlock_iothread();
}
return old;
}
void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(uint32_t),
uint32_t arg)
{
env->rdtime_fn = fn;
env->rdtime_fn_arg = arg;
}
void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
{
if (newpriv > PRV_M) {
g_assert_not_reached();
}
if (newpriv == PRV_H) {
newpriv = PRV_U;
}
/* tlb_flush is unnecessary as mode is contained in mmu_idx */
env->priv = newpriv;
/*
* Clear the load reservation - otherwise a reservation placed in one
* context/process can be used by another, resulting in an SC succeeding
* incorrectly. Version 2.2 of the ISA specification explicitly requires
* this behaviour, while later revisions say that the kernel "should" use
* an SC instruction to force the yielding of a load reservation on a
* preemptive context switch. As a result, do both.
*/
env->load_res = -1;
}
/*
* get_physical_address_pmp - check PMP permission for this physical address
*
* Match the PMP region and check permission for this physical address and it's
* TLB page. Returns 0 if the permission checking was successful
*
* @env: CPURISCVState
* @prot: The returned protection attributes
* @tlb_size: TLB page size containing addr. It could be modified after PMP
* permission checking. NULL if not set TLB page for addr.
* @addr: The physical address to be checked permission
* @access_type: The type of MMU access
* @mode: Indicates current privilege level.
*/
static int get_physical_address_pmp(CPURISCVState *env, int *prot,
target_ulong *tlb_size, hwaddr addr,
int size, MMUAccessType access_type,
int mode)
{
pmp_priv_t pmp_priv;
target_ulong tlb_size_pmp = 0;
if (!riscv_feature(env, RISCV_FEATURE_PMP)) {
*prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
return TRANSLATE_SUCCESS;
}
if (!pmp_hart_has_privs(env, addr, size, 1 << access_type, &pmp_priv,
mode)) {
*prot = 0;
return TRANSLATE_PMP_FAIL;
}
*prot = pmp_priv_to_page_prot(pmp_priv);
if (tlb_size != NULL) {
if (pmp_is_range_in_tlb(env, addr & ~(*tlb_size - 1), &tlb_size_pmp)) {
*tlb_size = tlb_size_pmp;
}
}
return TRANSLATE_SUCCESS;
}
/* get_physical_address - get the physical address for this virtual address
*
* Do a page table walk to obtain the physical address corresponding to a
* virtual address. Returns 0 if the translation was successful
*
* Adapted from Spike's mmu_t::translate and mmu_t::walk
*
* @env: CPURISCVState
* @physical: This will be set to the calculated physical address
* @prot: The returned protection attributes
* @addr: The virtual address to be translated
* @fault_pte_addr: If not NULL, this will be set to fault pte address
* when a error occurs on pte address translation.
* This will already be shifted to match htval.
* @access_type: The type of MMU access
* @mmu_idx: Indicates current privilege level
* @first_stage: Are we in first stage translation?
* Second stage is used for hypervisor guest translation
* @two_stage: Are we going to perform two stage translation
* @is_debug: Is this access from a debugger or the monitor?
*/
static int get_physical_address(CPURISCVState *env, hwaddr *physical,
int *prot, target_ulong addr,
target_ulong *fault_pte_addr,
int access_type, int mmu_idx,
bool first_stage, bool two_stage,
bool is_debug)
{
/* NOTE: the env->pc value visible here will not be
* correct, but the value visible to the exception handler
* (riscv_cpu_do_interrupt) is correct */
MemTxResult res;
MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
int mode = mmu_idx & TB_FLAGS_PRIV_MMU_MASK;
bool use_background = false;
/*
* Check if we should use the background registers for the two
* stage translation. We don't need to check if we actually need
* two stage translation as that happened before this function
* was called. Background registers will be used if the guest has
* forced a two stage translation to be on (in HS or M mode).
*/
if (!riscv_cpu_virt_enabled(env) && two_stage) {
use_background = true;
}
/* MPRV does not affect the virtual-machine load/store
instructions, HLV, HLVX, and HSV. */
if (riscv_cpu_two_stage_lookup(mmu_idx)) {
mode = get_field(env->hstatus, HSTATUS_SPVP);
} else if (mode == PRV_M && access_type != MMU_INST_FETCH) {
if (get_field(env->mstatus, MSTATUS_MPRV)) {
mode = get_field(env->mstatus, MSTATUS_MPP);
}
}
if (first_stage == false) {
/* We are in stage 2 translation, this is similar to stage 1. */
/* Stage 2 is always taken as U-mode */
mode = PRV_U;
}
if (mode == PRV_M || !riscv_feature(env, RISCV_FEATURE_MMU)) {
*physical = addr;
*prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
return TRANSLATE_SUCCESS;
}
*prot = 0;
hwaddr base;
int levels, ptidxbits, ptesize, vm, sum, mxr, widened;
if (first_stage == true) {
mxr = get_field(env->mstatus, MSTATUS_MXR);
} else {
mxr = get_field(env->vsstatus, MSTATUS_MXR);
}
if (first_stage == true) {
if (use_background) {
if (riscv_cpu_is_32bit(env)) {
base = (hwaddr)get_field(env->vsatp, SATP32_PPN) << PGSHIFT;
vm = get_field(env->vsatp, SATP32_MODE);
} else {
base = (hwaddr)get_field(env->vsatp, SATP64_PPN) << PGSHIFT;
vm = get_field(env->vsatp, SATP64_MODE);
}
} else {
if (riscv_cpu_is_32bit(env)) {
base = (hwaddr)get_field(env->satp, SATP32_PPN) << PGSHIFT;
vm = get_field(env->satp, SATP32_MODE);
} else {
base = (hwaddr)get_field(env->satp, SATP64_PPN) << PGSHIFT;
vm = get_field(env->satp, SATP64_MODE);
}
}
widened = 0;
} else {
if (riscv_cpu_is_32bit(env)) {
base = (hwaddr)get_field(env->hgatp, SATP32_PPN) << PGSHIFT;
vm = get_field(env->hgatp, SATP32_MODE);
} else {
base = (hwaddr)get_field(env->hgatp, SATP64_PPN) << PGSHIFT;
vm = get_field(env->hgatp, SATP64_MODE);
}
widened = 2;
}
/* status.SUM will be ignored if execute on background */
sum = get_field(env->mstatus, MSTATUS_SUM) || use_background || is_debug;
switch (vm) {
case VM_1_10_SV32:
levels = 2; ptidxbits = 10; ptesize = 4; break;
case VM_1_10_SV39:
levels = 3; ptidxbits = 9; ptesize = 8; break;
case VM_1_10_SV48:
levels = 4; ptidxbits = 9; ptesize = 8; break;
case VM_1_10_SV57:
levels = 5; ptidxbits = 9; ptesize = 8; break;
case VM_1_10_MBARE:
*physical = addr;
*prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
return TRANSLATE_SUCCESS;
default:
g_assert_not_reached();
}
CPUState *cs = env_cpu(env);
int va_bits = PGSHIFT + levels * ptidxbits + widened;
target_ulong mask, masked_msbs;
if (TARGET_LONG_BITS > (va_bits - 1)) {
mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
} else {
mask = 0;
}
masked_msbs = (addr >> (va_bits - 1)) & mask;
if (masked_msbs != 0 && masked_msbs != mask) {
return TRANSLATE_FAIL;
}
int ptshift = (levels - 1) * ptidxbits;
int i;
#if !TCG_OVERSIZED_GUEST
restart:
#endif
for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
target_ulong idx;
if (i == 0) {
idx = (addr >> (PGSHIFT + ptshift)) &
((1 << (ptidxbits + widened)) - 1);
} else {
idx = (addr >> (PGSHIFT + ptshift)) &
((1 << ptidxbits) - 1);
}
/* check that physical address of PTE is legal */
hwaddr pte_addr;
if (two_stage && first_stage) {
int vbase_prot;
hwaddr vbase;
/* Do the second stage translation on the base PTE address. */
int vbase_ret = get_physical_address(env, &vbase, &vbase_prot,
base, NULL, MMU_DATA_LOAD,
mmu_idx, false, true,
is_debug);
if (vbase_ret != TRANSLATE_SUCCESS) {
if (fault_pte_addr) {
*fault_pte_addr = (base + idx * ptesize) >> 2;
}
return TRANSLATE_G_STAGE_FAIL;
}
pte_addr = vbase + idx * ptesize;
} else {
pte_addr = base + idx * ptesize;
}
int pmp_prot;
int pmp_ret = get_physical_address_pmp(env, &pmp_prot, NULL, pte_addr,
sizeof(target_ulong),
MMU_DATA_LOAD, PRV_S);
if (pmp_ret != TRANSLATE_SUCCESS) {
return TRANSLATE_PMP_FAIL;
}
target_ulong pte;
if (riscv_cpu_is_32bit(env)) {
pte = address_space_ldl(cs->as, pte_addr, attrs, &res);
} else {
pte = address_space_ldq(cs->as, pte_addr, attrs, &res);
}
if (res != MEMTX_OK) {
return TRANSLATE_FAIL;
}
hwaddr ppn = pte >> PTE_PPN_SHIFT;
if (!(pte & PTE_V)) {
/* Invalid PTE */
return TRANSLATE_FAIL;
} else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
/* Inner PTE, continue walking */
base = ppn << PGSHIFT;
} else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
/* Reserved leaf PTE flags: PTE_W */
return TRANSLATE_FAIL;
} else if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
/* Reserved leaf PTE flags: PTE_W + PTE_X */
return TRANSLATE_FAIL;
} else if ((pte & PTE_U) && ((mode != PRV_U) &&
(!sum || access_type == MMU_INST_FETCH))) {
/* User PTE flags when not U mode and mstatus.SUM is not set,
or the access type is an instruction fetch */
return TRANSLATE_FAIL;
} else if (!(pte & PTE_U) && (mode != PRV_S)) {
/* Supervisor PTE flags when not S mode */
return TRANSLATE_FAIL;
} else if (ppn & ((1ULL << ptshift) - 1)) {
/* Misaligned PPN */
return TRANSLATE_FAIL;
} else if (access_type == MMU_DATA_LOAD && !((pte & PTE_R) ||
((pte & PTE_X) && mxr))) {
/* Read access check failed */
return TRANSLATE_FAIL;
} else if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
/* Write access check failed */
return TRANSLATE_FAIL;
} else if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
/* Fetch access check failed */
return TRANSLATE_FAIL;
} else {
/* if necessary, set accessed and dirty bits. */
target_ulong updated_pte = pte | PTE_A |
(access_type == MMU_DATA_STORE ? PTE_D : 0);
/* Page table updates need to be atomic with MTTCG enabled */
if (updated_pte != pte) {
/*
* - if accessed or dirty bits need updating, and the PTE is
* in RAM, then we do so atomically with a compare and swap.
* - if the PTE is in IO space or ROM, then it can't be updated
* and we return TRANSLATE_FAIL.
* - if the PTE changed by the time we went to update it, then
* it is no longer valid and we must re-walk the page table.
*/
MemoryRegion *mr;
hwaddr l = sizeof(target_ulong), addr1;
mr = address_space_translate(cs->as, pte_addr,
&addr1, &l, false, MEMTXATTRS_UNSPECIFIED);
if (memory_region_is_ram(mr)) {
target_ulong *pte_pa =
qemu_map_ram_ptr(mr->ram_block, addr1);
#if TCG_OVERSIZED_GUEST
/* MTTCG is not enabled on oversized TCG guests so
* page table updates do not need to be atomic */
*pte_pa = pte = updated_pte;
#else
target_ulong old_pte =
qatomic_cmpxchg(pte_pa, pte, updated_pte);
if (old_pte != pte) {
goto restart;
} else {
pte = updated_pte;
}
#endif
} else {
/* misconfigured PTE in ROM (AD bits are not preset) or
* PTE is in IO space and can't be updated atomically */
return TRANSLATE_FAIL;
}
}
/* for superpage mappings, make a fake leaf PTE for the TLB's
benefit. */
target_ulong vpn = addr >> PGSHIFT;
*physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) |
(addr & ~TARGET_PAGE_MASK);
/* set permissions on the TLB entry */
if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
*prot |= PAGE_READ;
}
if ((pte & PTE_X)) {
*prot |= PAGE_EXEC;
}
/* add write permission on stores or if the page is already dirty,
so that we TLB miss on later writes to update the dirty bit */
if ((pte & PTE_W) &&
(access_type == MMU_DATA_STORE || (pte & PTE_D))) {
*prot |= PAGE_WRITE;
}
return TRANSLATE_SUCCESS;
}
}
return TRANSLATE_FAIL;
}
static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
MMUAccessType access_type, bool pmp_violation,
bool first_stage, bool two_stage)
{
CPUState *cs = env_cpu(env);
int page_fault_exceptions, vm;
uint64_t stap_mode;
if (riscv_cpu_is_32bit(env)) {
stap_mode = SATP32_MODE;
} else {
stap_mode = SATP64_MODE;
}
if (first_stage) {
vm = get_field(env->satp, stap_mode);
} else {
vm = get_field(env->hgatp, stap_mode);
}
page_fault_exceptions = vm != VM_1_10_MBARE && !pmp_violation;
switch (access_type) {
case MMU_INST_FETCH:
if (riscv_cpu_virt_enabled(env) && !first_stage) {
cs->exception_index = RISCV_EXCP_INST_GUEST_PAGE_FAULT;
} else {
cs->exception_index = page_fault_exceptions ?
RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
}
break;
case MMU_DATA_LOAD:
if (two_stage && !first_stage) {
cs->exception_index = RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT;
} else {
cs->exception_index = page_fault_exceptions ?
RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
}
break;
case MMU_DATA_STORE:
if (two_stage && !first_stage) {
cs->exception_index = RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT;
} else {
cs->exception_index = page_fault_exceptions ?
RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
}
break;
default:
g_assert_not_reached();
}
env->badaddr = address;
env->two_stage_lookup = two_stage;
}
hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
hwaddr phys_addr;
int prot;
int mmu_idx = cpu_mmu_index(&cpu->env, false);
if (get_physical_address(env, &phys_addr, &prot, addr, NULL, 0, mmu_idx,
true, riscv_cpu_virt_enabled(env), true)) {
return -1;
}
if (riscv_cpu_virt_enabled(env)) {
if (get_physical_address(env, &phys_addr, &prot, phys_addr, NULL,
0, mmu_idx, false, true, true)) {
return -1;
}
}
return phys_addr & TARGET_PAGE_MASK;
}
void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
vaddr addr, unsigned size,
MMUAccessType access_type,
int mmu_idx, MemTxAttrs attrs,
MemTxResult response, uintptr_t retaddr)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
if (access_type == MMU_DATA_STORE) {
cs->exception_index = RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
} else if (access_type == MMU_DATA_LOAD) {
cs->exception_index = RISCV_EXCP_LOAD_ACCESS_FAULT;
} else {
cs->exception_index = RISCV_EXCP_INST_ACCESS_FAULT;
}
env->badaddr = addr;
env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
riscv_cpu_two_stage_lookup(mmu_idx);
riscv_raise_exception(&cpu->env, cs->exception_index, retaddr);
}
void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
MMUAccessType access_type, int mmu_idx,
uintptr_t retaddr)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
switch (access_type) {
case MMU_INST_FETCH:
cs->exception_index = RISCV_EXCP_INST_ADDR_MIS;
break;
case MMU_DATA_LOAD:
cs->exception_index = RISCV_EXCP_LOAD_ADDR_MIS;
break;
case MMU_DATA_STORE:
cs->exception_index = RISCV_EXCP_STORE_AMO_ADDR_MIS;
break;
default:
g_assert_not_reached();
}
env->badaddr = addr;
env->two_stage_lookup = riscv_cpu_virt_enabled(env) ||
riscv_cpu_two_stage_lookup(mmu_idx);
riscv_raise_exception(env, cs->exception_index, retaddr);
}
#endif /* !CONFIG_USER_ONLY */
bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
MMUAccessType access_type, int mmu_idx,
bool probe, uintptr_t retaddr)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
#ifndef CONFIG_USER_ONLY
vaddr im_address;
hwaddr pa = 0;
int prot, prot2, prot_pmp;
bool pmp_violation = false;
bool first_stage_error = true;
bool two_stage_lookup = false;
int ret = TRANSLATE_FAIL;
int mode = mmu_idx;
/* default TLB page size */
target_ulong tlb_size = TARGET_PAGE_SIZE;
env->guest_phys_fault_addr = 0;
qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
__func__, address, access_type, mmu_idx);
/* MPRV does not affect the virtual-machine load/store
instructions, HLV, HLVX, and HSV. */
if (riscv_cpu_two_stage_lookup(mmu_idx)) {
mode = get_field(env->hstatus, HSTATUS_SPVP);
} else if (mode == PRV_M && access_type != MMU_INST_FETCH &&
get_field(env->mstatus, MSTATUS_MPRV)) {
mode = get_field(env->mstatus, MSTATUS_MPP);
if (riscv_has_ext(env, RVH) && get_field(env->mstatus, MSTATUS_MPV)) {
two_stage_lookup = true;
}
}
if (riscv_cpu_virt_enabled(env) ||
((riscv_cpu_two_stage_lookup(mmu_idx) || two_stage_lookup) &&
access_type != MMU_INST_FETCH)) {
/* Two stage lookup */
ret = get_physical_address(env, &pa, &prot, address,
&env->guest_phys_fault_addr, access_type,
mmu_idx, true, true, false);
/*
* A G-stage exception may be triggered during two state lookup.
* And the env->guest_phys_fault_addr has already been set in
* get_physical_address().
*/
if (ret == TRANSLATE_G_STAGE_FAIL) {
first_stage_error = false;
access_type = MMU_DATA_LOAD;
}
qemu_log_mask(CPU_LOG_MMU,
"%s 1st-stage address=%" VADDR_PRIx " ret %d physical "
TARGET_FMT_plx " prot %d\n",
__func__, address, ret, pa, prot);
if (ret == TRANSLATE_SUCCESS) {
/* Second stage lookup */
im_address = pa;
ret = get_physical_address(env, &pa, &prot2, im_address, NULL,
access_type, mmu_idx, false, true,
false);
qemu_log_mask(CPU_LOG_MMU,
"%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
TARGET_FMT_plx " prot %d\n",
__func__, im_address, ret, pa, prot2);
prot &= prot2;
if (ret == TRANSLATE_SUCCESS) {
ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
size, access_type, mode);
qemu_log_mask(CPU_LOG_MMU,
"%s PMP address=" TARGET_FMT_plx " ret %d prot"
" %d tlb_size " TARGET_FMT_lu "\n",
__func__, pa, ret, prot_pmp, tlb_size);
prot &= prot_pmp;
}
if (ret != TRANSLATE_SUCCESS) {
/*
* Guest physical address translation failed, this is a HS
* level exception
*/
first_stage_error = false;
env->guest_phys_fault_addr = (im_address |
(address &
(TARGET_PAGE_SIZE - 1))) >> 2;
}
}
} else {
/* Single stage lookup */
ret = get_physical_address(env, &pa, &prot, address, NULL,
access_type, mmu_idx, true, false, false);
qemu_log_mask(CPU_LOG_MMU,
"%s address=%" VADDR_PRIx " ret %d physical "
TARGET_FMT_plx " prot %d\n",
__func__, address, ret, pa, prot);
if (ret == TRANSLATE_SUCCESS) {
ret = get_physical_address_pmp(env, &prot_pmp, &tlb_size, pa,
size, access_type, mode);
qemu_log_mask(CPU_LOG_MMU,
"%s PMP address=" TARGET_FMT_plx " ret %d prot"
" %d tlb_size " TARGET_FMT_lu "\n",
__func__, pa, ret, prot_pmp, tlb_size);
prot &= prot_pmp;
}
}
if (ret == TRANSLATE_PMP_FAIL) {
pmp_violation = true;
}
if (ret == TRANSLATE_SUCCESS) {
tlb_set_page(cs, address & ~(tlb_size - 1), pa & ~(tlb_size - 1),
prot, mmu_idx, tlb_size);
return true;
} else if (probe) {
return false;
} else {
raise_mmu_exception(env, address, access_type, pmp_violation,
first_stage_error,
riscv_cpu_virt_enabled(env) ||
riscv_cpu_two_stage_lookup(mmu_idx));
riscv_raise_exception(env, cs->exception_index, retaddr);
}
return true;
#else
switch (access_type) {
case MMU_INST_FETCH:
cs->exception_index = RISCV_EXCP_INST_PAGE_FAULT;
break;
case MMU_DATA_LOAD:
cs->exception_index = RISCV_EXCP_LOAD_PAGE_FAULT;
break;
case MMU_DATA_STORE:
cs->exception_index = RISCV_EXCP_STORE_PAGE_FAULT;
break;
default:
g_assert_not_reached();
}
env->badaddr = address;
cpu_loop_exit_restore(cs, retaddr);
#endif
}
/*
* Handle Traps
*
* Adapted from Spike's processor_t::take_trap.
*
*/
void riscv_cpu_do_interrupt(CPUState *cs)
{
#if !defined(CONFIG_USER_ONLY)
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
bool force_hs_execp = riscv_cpu_force_hs_excep_enabled(env);
uint64_t s;
/* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
* so we mask off the MSB and separate into trap type and cause.
*/
bool async = !!(cs->exception_index & RISCV_EXCP_INT_FLAG);
target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
target_ulong deleg = async ? env->mideleg : env->medeleg;
bool write_tval = false;
target_ulong tval = 0;
target_ulong htval = 0;
target_ulong mtval2 = 0;
if (cause == RISCV_EXCP_SEMIHOST) {
if (env->priv >= PRV_S) {
env->gpr[xA0] = do_common_semihosting(cs);
env->pc += 4;
return;
}
cause = RISCV_EXCP_BREAKPOINT;
}
if (!async) {
/* set tval to badaddr for traps with address information */
switch (cause) {
case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
force_hs_execp = true;
/* fallthrough */
case RISCV_EXCP_INST_ADDR_MIS:
case RISCV_EXCP_INST_ACCESS_FAULT:
case RISCV_EXCP_LOAD_ADDR_MIS:
case RISCV_EXCP_STORE_AMO_ADDR_MIS:
case RISCV_EXCP_LOAD_ACCESS_FAULT:
case RISCV_EXCP_STORE_AMO_ACCESS_FAULT:
case RISCV_EXCP_INST_PAGE_FAULT:
case RISCV_EXCP_LOAD_PAGE_FAULT:
case RISCV_EXCP_STORE_PAGE_FAULT:
write_tval = true;
tval = env->badaddr;
break;
default:
break;
}
/* ecall is dispatched as one cause so translate based on mode */
if (cause == RISCV_EXCP_U_ECALL) {
assert(env->priv <= 3);
if (env->priv == PRV_M) {
cause = RISCV_EXCP_M_ECALL;
} else if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
cause = RISCV_EXCP_VS_ECALL;
} else if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) {
cause = RISCV_EXCP_S_ECALL;
} else if (env->priv == PRV_U) {
cause = RISCV_EXCP_U_ECALL;
}
}
}
trace_riscv_trap(env->mhartid, async, cause, env->pc, tval,
riscv_cpu_get_trap_name(cause, async));
qemu_log_mask(CPU_LOG_INT,
"%s: hart:"TARGET_FMT_ld", async:%d, cause:"TARGET_FMT_lx", "
"epc:0x"TARGET_FMT_lx", tval:0x"TARGET_FMT_lx", desc=%s\n",
__func__, env->mhartid, async, cause, env->pc, tval,
riscv_cpu_get_trap_name(cause, async));
if (env->priv <= PRV_S &&
cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
/* handle the trap in S-mode */
if (riscv_has_ext(env, RVH)) {
target_ulong hdeleg = async ? env->hideleg : env->hedeleg;
if (env->two_stage_lookup && write_tval) {
/*
* If we are writing a guest virtual address to stval, set
* this to 1. If we are trapping to VS we will set this to 0
* later.
*/
env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 1);
} else {
/* For other HS-mode traps, we set this to 0. */
env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 0);
}
if (riscv_cpu_virt_enabled(env) && ((hdeleg >> cause) & 1) &&
!force_hs_execp) {
/* Trap to VS mode */
/*
* See if we need to adjust cause. Yes if its VS mode interrupt
* no if hypervisor has delegated one of hs mode's interrupt
*/
if (cause == IRQ_VS_TIMER || cause == IRQ_VS_SOFT ||
cause == IRQ_VS_EXT) {
cause = cause - 1;
}
env->hstatus = set_field(env->hstatus, HSTATUS_GVA, 0);
} else if (riscv_cpu_virt_enabled(env)) {
/* Trap into HS mode, from virt */
riscv_cpu_swap_hypervisor_regs(env);
env->hstatus = set_field(env->hstatus, HSTATUS_SPVP,
env->priv);
env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
riscv_cpu_virt_enabled(env));
htval = env->guest_phys_fault_addr;
riscv_cpu_set_virt_enabled(env, 0);
riscv_cpu_set_force_hs_excep(env, 0);
} else {
/* Trap into HS mode */
env->hstatus = set_field(env->hstatus, HSTATUS_SPV, false);
htval = env->guest_phys_fault_addr;
}
}
s = env->mstatus;
s = set_field(s, MSTATUS_SPIE, get_field(s, MSTATUS_SIE));
s = set_field(s, MSTATUS_SPP, env->priv);
s = set_field(s, MSTATUS_SIE, 0);
env->mstatus = s;
env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
env->sepc = env->pc;
env->stval = tval;
env->htval = htval;
env->pc = (env->stvec >> 2 << 2) +
((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
riscv_cpu_set_mode(env, PRV_S);
} else {
/* handle the trap in M-mode */
if (riscv_has_ext(env, RVH)) {
if (riscv_cpu_virt_enabled(env)) {
riscv_cpu_swap_hypervisor_regs(env);
}
env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
riscv_cpu_virt_enabled(env));
if (riscv_cpu_virt_enabled(env) && tval) {
env->mstatus = set_field(env->mstatus, MSTATUS_GVA, 1);
}
mtval2 = env->guest_phys_fault_addr;
/* Trapping to M mode, virt is disabled */
riscv_cpu_set_virt_enabled(env, 0);
riscv_cpu_set_force_hs_excep(env, 0);
}
s = env->mstatus;
s = set_field(s, MSTATUS_MPIE, get_field(s, MSTATUS_MIE));
s = set_field(s, MSTATUS_MPP, env->priv);
s = set_field(s, MSTATUS_MIE, 0);
env->mstatus = s;
env->mcause = cause | ~(((target_ulong)-1) >> async);
env->mepc = env->pc;
env->mtval = tval;
env->mtval2 = mtval2;
env->pc = (env->mtvec >> 2 << 2) +
((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
riscv_cpu_set_mode(env, PRV_M);
}
/* NOTE: it is not necessary to yield load reservations here. It is only
* necessary for an SC from "another hart" to cause a load reservation
* to be yielded. Refer to the memory consistency model section of the
* RISC-V ISA Specification.
*/
env->two_stage_lookup = false;
#endif
cs->exception_index = RISCV_EXCP_NONE; /* mark handled to qemu */
}
|