summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kvm/hyp.S
blob: 1599701ef044b28b2534a3766dde1d255dba103a (plain)
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
/*
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that 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 <linux/linkage.h>

#include <asm/alternative.h>
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
#include <asm/cpufeature.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
#include <asm/fpsimdmacros.h>
#include <asm/kvm.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmu.h>
#include <asm/memory.h>

#define CPU_GP_REG_OFFSET(x)	(CPU_GP_REGS + x)
#define CPU_XREG_OFFSET(x)	CPU_GP_REG_OFFSET(CPU_USER_PT_REGS + 8*x)
#define CPU_SPSR_OFFSET(x)	CPU_GP_REG_OFFSET(CPU_SPSR + 8*x)
#define CPU_SYSREG_OFFSET(x)	(CPU_SYSREGS + 8*x)

	.text
	.pushsection	.hyp.text, "ax"
	.align	PAGE_SHIFT

.macro save_common_regs
	// x2: base address for cpu context
	// x3: tmp register

	add	x3, x2, #CPU_XREG_OFFSET(19)
	stp	x19, x20, [x3]
	stp	x21, x22, [x3, #16]
	stp	x23, x24, [x3, #32]
	stp	x25, x26, [x3, #48]
	stp	x27, x28, [x3, #64]
	stp	x29, lr, [x3, #80]

	mrs	x19, sp_el0
	mrs	x20, elr_el2		// pc before entering el2
	mrs	x21, spsr_el2		// pstate before entering el2

	stp	x19, x20, [x3, #96]
	str	x21, [x3, #112]

	mrs	x22, sp_el1
	mrs	x23, elr_el1
	mrs	x24, spsr_el1

	str	x22, [x2, #CPU_GP_REG_OFFSET(CPU_SP_EL1)]
	str	x23, [x2, #CPU_GP_REG_OFFSET(CPU_ELR_EL1)]
	str	x24, [x2, #CPU_SPSR_OFFSET(KVM_SPSR_EL1)]
.endm

.macro restore_common_regs
	// x2: base address for cpu context
	// x3: tmp register

	ldr	x22, [x2, #CPU_GP_REG_OFFSET(CPU_SP_EL1)]
	ldr	x23, [x2, #CPU_GP_REG_OFFSET(CPU_ELR_EL1)]
	ldr	x24, [x2, #CPU_SPSR_OFFSET(KVM_SPSR_EL1)]

	msr	sp_el1, x22
	msr	elr_el1, x23
	msr	spsr_el1, x24

	add	x3, x2, #CPU_XREG_OFFSET(31)    // SP_EL0
	ldp	x19, x20, [x3]
	ldr	x21, [x3, #16]

	msr	sp_el0, x19
	msr	elr_el2, x20 		// pc on return from el2
	msr	spsr_el2, x21 		// pstate on return from el2

	add	x3, x2, #CPU_XREG_OFFSET(19)
	ldp	x19, x20, [x3]
	ldp	x21, x22, [x3, #16]
	ldp	x23, x24, [x3, #32]
	ldp	x25, x26, [x3, #48]
	ldp	x27, x28, [x3, #64]
	ldp	x29, lr, [x3, #80]
.endm

.macro save_host_regs
	save_common_regs
.endm

.macro restore_host_regs
	restore_common_regs
.endm

.macro save_fpsimd
	// x2: cpu context address
	// x3, x4: tmp regs
	add	x3, x2, #CPU_GP_REG_OFFSET(CPU_FP_REGS)
	fpsimd_save x3, 4
.endm

.macro restore_fpsimd
	// x2: cpu context address
	// x3, x4: tmp regs
	add	x3, x2, #CPU_GP_REG_OFFSET(CPU_FP_REGS)
	fpsimd_restore x3, 4
.endm

.macro save_guest_regs
	// x0 is the vcpu address
	// x1 is the return code, do not corrupt!
	// x2 is the cpu context
	// x3 is a tmp register
	// Guest's x0-x3 are on the stack

	// Compute base to save registers
	add	x3, x2, #CPU_XREG_OFFSET(4)
	stp	x4, x5, [x3]
	stp	x6, x7, [x3, #16]
	stp	x8, x9, [x3, #32]
	stp	x10, x11, [x3, #48]
	stp	x12, x13, [x3, #64]
	stp	x14, x15, [x3, #80]
	stp	x16, x17, [x3, #96]
	str	x18, [x3, #112]

	pop	x6, x7			// x2, x3
	pop	x4, x5			// x0, x1

	add	x3, x2, #CPU_XREG_OFFSET(0)
	stp	x4, x5, [x3]
	stp	x6, x7, [x3, #16]

	save_common_regs
.endm

.macro restore_guest_regs
	// x0 is the vcpu address.
	// x2 is the cpu context
	// x3 is a tmp register

	// Prepare x0-x3 for later restore
	add	x3, x2, #CPU_XREG_OFFSET(0)
	ldp	x4, x5, [x3]
	ldp	x6, x7, [x3, #16]
	push	x4, x5		// Push x0-x3 on the stack
	push	x6, x7

	// x4-x18
	ldp	x4, x5, [x3, #32]
	ldp	x6, x7, [x3, #48]
	ldp	x8, x9, [x3, #64]
	ldp	x10, x11, [x3, #80]
	ldp	x12, x13, [x3, #96]
	ldp	x14, x15, [x3, #112]
	ldp	x16, x17, [x3, #128]
	ldr	x18, [x3, #144]

	// x19-x29, lr, sp*, elr*, spsr*
	restore_common_regs

	// Last bits of the 64bit state
	pop	x2, x3
	pop	x0, x1

	// Do not touch any register after this!
.endm

/*
 * Macros to perform system register save/restore.
 *
 * Ordering here is absolutely critical, and must be kept consistent
 * in {save,restore}_sysregs, {save,restore}_guest_32bit_state,
 * and in kvm_asm.h.
 *
 * In other words, don't touch any of these unless you know what
 * you are doing.
 */
.macro save_sysregs
	// x2: base address for cpu context
	// x3: tmp register

	add	x3, x2, #CPU_SYSREG_OFFSET(MPIDR_EL1)

	mrs	x4,	vmpidr_el2
	mrs	x5,	csselr_el1
	mrs	x6,	sctlr_el1
	mrs	x7,	actlr_el1
	mrs	x8,	cpacr_el1
	mrs	x9,	ttbr0_el1
	mrs	x10,	ttbr1_el1
	mrs	x11,	tcr_el1
	mrs	x12,	esr_el1
	mrs	x13, 	afsr0_el1
	mrs	x14,	afsr1_el1
	mrs	x15,	far_el1
	mrs	x16,	mair_el1
	mrs	x17,	vbar_el1
	mrs	x18,	contextidr_el1
	mrs	x19,	tpidr_el0
	mrs	x20,	tpidrro_el0
	mrs	x21,	tpidr_el1
	mrs	x22, 	amair_el1
	mrs	x23, 	cntkctl_el1
	mrs	x24,	par_el1
	mrs	x25,	mdscr_el1

	stp	x4, x5, [x3]
	stp	x6, x7, [x3, #16]
	stp	x8, x9, [x3, #32]
	stp	x10, x11, [x3, #48]
	stp	x12, x13, [x3, #64]
	stp	x14, x15, [x3, #80]
	stp	x16, x17, [x3, #96]
	stp	x18, x19, [x3, #112]
	stp	x20, x21, [x3, #128]
	stp	x22, x23, [x3, #144]
	stp	x24, x25, [x3, #160]
.endm

.macro save_debug type
	// x4: pointer to register set
	// x5: number of registers to skip
	// x6..x22 trashed

	adr	x22, 1f
	add	x22, x22, x5, lsl #2
	br	x22
1:
	mrs	x21, \type\()15_el1
	mrs	x20, \type\()14_el1
	mrs	x19, \type\()13_el1
	mrs	x18, \type\()12_el1
	mrs	x17, \type\()11_el1
	mrs	x16, \type\()10_el1
	mrs	x15, \type\()9_el1
	mrs	x14, \type\()8_el1
	mrs	x13, \type\()7_el1
	mrs	x12, \type\()6_el1
	mrs	x11, \type\()5_el1
	mrs	x10, \type\()4_el1
	mrs	x9, \type\()3_el1
	mrs	x8, \type\()2_el1
	mrs	x7, \type\()1_el1
	mrs	x6, \type\()0_el1

	adr	x22, 1f
	add	x22, x22, x5, lsl #2
	br	x22
1:
	str	x21, [x4, #(15 * 8)]
	str	x20, [x4, #(14 * 8)]
	str	x19, [x4, #(13 * 8)]
	str	x18, [x4, #(12 * 8)]
	str	x17, [x4, #(11 * 8)]
	str	x16, [x4, #(10 * 8)]
	str	x15, [x4, #(9 * 8)]
	str	x14, [x4, #(8 * 8)]
	str	x13, [x4, #(7 * 8)]
	str	x12, [x4, #(6 * 8)]
	str	x11, [x4, #(5 * 8)]
	str	x10, [x4, #(4 * 8)]
	str	x9, [x4, #(3 * 8)]
	str	x8, [x4, #(2 * 8)]
	str	x7, [x4, #(1 * 8)]
	str	x6, [x4, #(0 * 8)]
.endm

.macro restore_sysregs
	// x2: base address for cpu context
	// x3: tmp register

	add	x3, x2, #CPU_SYSREG_OFFSET(MPIDR_EL1)

	ldp	x4, x5, [x3]
	ldp	x6, x7, [x3, #16]
	ldp	x8, x9, [x3, #32]
	ldp	x10, x11, [x3, #48]
	ldp	x12, x13, [x3, #64]
	ldp	x14, x15, [x3, #80]
	ldp	x16, x17, [x3, #96]
	ldp	x18, x19, [x3, #112]
	ldp	x20, x21, [x3, #128]
	ldp	x22, x23, [x3, #144]
	ldp	x24, x25, [x3, #160]

	msr	vmpidr_el2,	x4
	msr	csselr_el1,	x5
	msr	sctlr_el1,	x6
	msr	actlr_el1,	x7
	msr	cpacr_el1,	x8
	msr	ttbr0_el1,	x9
	msr	ttbr1_el1,	x10
	msr	tcr_el1,	x11
	msr	esr_el1,	x12
	msr	afsr0_el1,	x13
	msr	afsr1_el1,	x14
	msr	far_el1,	x15
	msr	mair_el1,	x16
	msr	vbar_el1,	x17
	msr	contextidr_el1,	x18
	msr	tpidr_el0,	x19
	msr	tpidrro_el0,	x20
	msr	tpidr_el1,	x21
	msr	amair_el1,	x22
	msr	cntkctl_el1,	x23
	msr	par_el1,	x24
	msr	mdscr_el1,	x25
.endm

.macro restore_debug type
	// x4: pointer to register set
	// x5: number of registers to skip
	// x6..x22 trashed

	adr	x22, 1f
	add	x22, x22, x5, lsl #2
	br	x22
1:
	ldr	x21, [x4, #(15 * 8)]
	ldr	x20, [x4, #(14 * 8)]
	ldr	x19, [x4, #(13 * 8)]
	ldr	x18, [x4, #(12 * 8)]
	ldr	x17, [x4, #(11 * 8)]
	ldr	x16, [x4, #(10 * 8)]
	ldr	x15, [x4, #(9 * 8)]
	ldr	x14, [x4, #(8 * 8)]
	ldr	x13, [x4, #(7 * 8)]
	ldr	x12, [x4, #(6 * 8)]
	ldr	x11, [x4, #(5 * 8)]
	ldr	x10, [x4, #(4 * 8)]
	ldr	x9, [x4, #(3 * 8)]
	ldr	x8, [x4, #(2 * 8)]
	ldr	x7, [x4, #(1 * 8)]
	ldr	x6, [x4, #(0 * 8)]

	adr	x22, 1f
	add	x22, x22, x5, lsl #2
	br	x22
1:
	msr	\type\()15_el1, x21
	msr	\type\()14_el1, x20
	msr	\type\()13_el1, x19
	msr	\type\()12_el1, x18
	msr	\type\()11_el1, x17
	msr	\type\()10_el1, x16
	msr	\type\()9_el1, x15
	msr	\type\()8_el1, x14
	msr	\type\()7_el1, x13
	msr	\type\()6_el1, x12
	msr	\type\()5_el1, x11
	msr	\type\()4_el1, x10
	msr	\type\()3_el1, x9
	msr	\type\()2_el1, x8
	msr	\type\()1_el1, x7
	msr	\type\()0_el1, x6
.endm

.macro skip_32bit_state tmp, target
	// Skip 32bit state if not needed
	mrs	\tmp, hcr_el2
	tbnz	\tmp, #HCR_RW_SHIFT, \target
.endm

.macro skip_tee_state tmp, target
	// Skip ThumbEE state if not needed
	mrs	\tmp, id_pfr0_el1
	tbz	\tmp, #12, \target
.endm

.macro skip_debug_state tmp, target
	ldr	\tmp, [x0, #VCPU_DEBUG_FLAGS]
	tbz	\tmp, #KVM_ARM64_DEBUG_DIRTY_SHIFT, \target
.endm

/*
 * Branch to target if CPTR_EL2.TFP bit is set (VFP/SIMD trapping enabled)
 */
.macro skip_fpsimd_state tmp, target
	mrs	\tmp, cptr_el2
	tbnz	\tmp, #CPTR_EL2_TFP_SHIFT, \target
.endm

.macro compute_debug_state target
	// Compute debug state: If any of KDE, MDE or KVM_ARM64_DEBUG_DIRTY
	// is set, we do a full save/restore cycle and disable trapping.
	add	x25, x0, #VCPU_CONTEXT

	// Check the state of MDSCR_EL1
	ldr	x25, [x25, #CPU_SYSREG_OFFSET(MDSCR_EL1)]
	and	x26, x25, #DBG_MDSCR_KDE
	and	x25, x25, #DBG_MDSCR_MDE
	adds	xzr, x25, x26
	b.eq	9998f		// Nothing to see there

	// If any interesting bits was set, we must set the flag
	mov	x26, #KVM_ARM64_DEBUG_DIRTY
	str	x26, [x0, #VCPU_DEBUG_FLAGS]
	b	9999f		// Don't skip restore

9998:
	// Otherwise load the flags from memory in case we recently
	// trapped
	skip_debug_state x25, \target
9999:
.endm

.macro save_guest_32bit_state
	skip_32bit_state x3, 1f

	add	x3, x2, #CPU_SPSR_OFFSET(KVM_SPSR_ABT)
	mrs	x4, spsr_abt
	mrs	x5, spsr_und
	mrs	x6, spsr_irq
	mrs	x7, spsr_fiq
	stp	x4, x5, [x3]
	stp	x6, x7, [x3, #16]

	add	x3, x2, #CPU_SYSREG_OFFSET(DACR32_EL2)
	mrs	x4, dacr32_el2
	mrs	x5, ifsr32_el2
	stp	x4, x5, [x3]

	skip_fpsimd_state x8, 2f
	mrs	x6, fpexc32_el2
	str	x6, [x3, #16]
2:
	skip_debug_state x8, 1f
	mrs	x7, dbgvcr32_el2
	str	x7, [x3, #24]
1:
.endm

.macro restore_guest_32bit_state
	skip_32bit_state x3, 1f

	add	x3, x2, #CPU_SPSR_OFFSET(KVM_SPSR_ABT)
	ldp	x4, x5, [x3]
	ldp	x6, x7, [x3, #16]
	msr	spsr_abt, x4
	msr	spsr_und, x5
	msr	spsr_irq, x6
	msr	spsr_fiq, x7

	add	x3, x2, #CPU_SYSREG_OFFSET(DACR32_EL2)
	ldp	x4, x5, [x3]
	msr	dacr32_el2, x4
	msr	ifsr32_el2, x5

	skip_debug_state x8, 1f
	ldr	x7, [x3, #24]
	msr	dbgvcr32_el2, x7
1:
.endm

.macro activate_traps
	ldr     x2, [x0, #VCPU_HCR_EL2]

	/*
	 * We are about to set CPTR_EL2.TFP to trap all floating point
	 * register accesses to EL2, however, the ARM ARM clearly states that
	 * traps are only taken to EL2 if the operation would not otherwise
	 * trap to EL1.  Therefore, always make sure that for 32-bit guests,
	 * we set FPEXC.EN to prevent traps to EL1, when setting the TFP bit.
	 */
	tbnz	x2, #HCR_RW_SHIFT, 99f // open code skip_32bit_state
	mov	x3, #(1 << 30)
	msr	fpexc32_el2, x3
	isb
99:
	msr     hcr_el2, x2
	mov	x2, #CPTR_EL2_TTA
	orr     x2, x2, #CPTR_EL2_TFP
	msr	cptr_el2, x2

	mov	x2, #(1 << 15)	// Trap CP15 Cr=15
	msr	hstr_el2, x2

	// Monitor Debug Config - see kvm_arm_setup_debug()
	ldr	x2, [x0, #VCPU_MDCR_EL2]
	msr	mdcr_el2, x2
.endm

.macro deactivate_traps
	mov	x2, #HCR_RW
	msr	hcr_el2, x2
	msr	hstr_el2, xzr

	mrs	x2, mdcr_el2
	and	x2, x2, #MDCR_EL2_HPMN_MASK
	msr	mdcr_el2, x2
.endm

.macro activate_vm
	ldr	x1, [x0, #VCPU_KVM]
	kern_hyp_va	x1
	ldr	x2, [x1, #KVM_VTTBR]
	msr	vttbr_el2, x2
.endm

.macro deactivate_vm
	msr	vttbr_el2, xzr
.endm

/*
 * Call into the vgic backend for state saving
 */
.macro save_vgic_state
alternative_if_not ARM64_HAS_SYSREG_GIC_CPUIF
	bl	__save_vgic_v2_state
alternative_else
	bl	__save_vgic_v3_state
alternative_endif
	mrs	x24, hcr_el2
	mov	x25, #HCR_INT_OVERRIDE
	neg	x25, x25
	and	x24, x24, x25
	msr	hcr_el2, x24
.endm

/*
 * Call into the vgic backend for state restoring
 */
.macro restore_vgic_state
	mrs	x24, hcr_el2
	ldr	x25, [x0, #VCPU_IRQ_LINES]
	orr	x24, x24, #HCR_INT_OVERRIDE
	orr	x24, x24, x25
	msr	hcr_el2, x24
alternative_if_not ARM64_HAS_SYSREG_GIC_CPUIF
	bl	__restore_vgic_v2_state
alternative_else
	bl	__restore_vgic_v3_state
alternative_endif
.endm

.macro save_timer_state
	// x0: vcpu pointer
	ldr	x2, [x0, #VCPU_KVM]
	kern_hyp_va x2
	ldr	w3, [x2, #KVM_TIMER_ENABLED]
	cbz	w3, 1f

	mrs	x3, cntv_ctl_el0
	and	x3, x3, #3
	str	w3, [x0, #VCPU_TIMER_CNTV_CTL]

	isb

	mrs	x3, cntv_cval_el0
	str	x3, [x0, #VCPU_TIMER_CNTV_CVAL]

1:
	// Disable the virtual timer
	msr	cntv_ctl_el0, xzr

	// Allow physical timer/counter access for the host
	mrs	x2, cnthctl_el2
	orr	x2, x2, #3
	msr	cnthctl_el2, x2

	// Clear cntvoff for the host
	msr	cntvoff_el2, xzr
.endm

.macro restore_timer_state
	// x0: vcpu pointer
	// Disallow physical timer access for the guest
	// Physical counter access is allowed
	mrs	x2, cnthctl_el2
	orr	x2, x2, #1
	bic	x2, x2, #2
	msr	cnthctl_el2, x2

	ldr	x2, [x0, #VCPU_KVM]
	kern_hyp_va x2
	ldr	w3, [x2, #KVM_TIMER_ENABLED]
	cbz	w3, 1f

	ldr	x3, [x2, #KVM_TIMER_CNTVOFF]
	msr	cntvoff_el2, x3
	ldr	x2, [x0, #VCPU_TIMER_CNTV_CVAL]
	msr	cntv_cval_el0, x2
	isb

	ldr	w2, [x0, #VCPU_TIMER_CNTV_CTL]
	and	x2, x2, #3
	msr	cntv_ctl_el0, x2
1:
.endm

__save_sysregs:
	save_sysregs
	ret

__restore_sysregs:
	restore_sysregs
	ret

/* Save debug state */
__save_debug:
	// x2: ptr to CPU context
	// x3: ptr to debug reg struct
	// x4/x5/x6-22/x24-26: trashed

	mrs	x26, id_aa64dfr0_el1
	ubfx	x24, x26, #12, #4	// Extract BRPs
	ubfx	x25, x26, #20, #4	// Extract WRPs
	mov	w26, #15
	sub	w24, w26, w24		// How many BPs to skip
	sub	w25, w26, w25		// How many WPs to skip

	mov	x5, x24
	add	x4, x3, #DEBUG_BCR
	save_debug dbgbcr
	add	x4, x3, #DEBUG_BVR
	save_debug dbgbvr

	mov	x5, x25
	add	x4, x3, #DEBUG_WCR
	save_debug dbgwcr
	add	x4, x3, #DEBUG_WVR
	save_debug dbgwvr

	mrs	x21, mdccint_el1
	str	x21, [x2, #CPU_SYSREG_OFFSET(MDCCINT_EL1)]
	ret

/* Restore debug state */
__restore_debug:
	// x2: ptr to CPU context
	// x3: ptr to debug reg struct
	// x4/x5/x6-22/x24-26: trashed

	mrs	x26, id_aa64dfr0_el1
	ubfx	x24, x26, #12, #4	// Extract BRPs
	ubfx	x25, x26, #20, #4	// Extract WRPs
	mov	w26, #15
	sub	w24, w26, w24		// How many BPs to skip
	sub	w25, w26, w25		// How many WPs to skip

	mov	x5, x24
	add	x4, x3, #DEBUG_BCR
	restore_debug dbgbcr
	add	x4, x3, #DEBUG_BVR
	restore_debug dbgbvr

	mov	x5, x25
	add	x4, x3, #DEBUG_WCR
	restore_debug dbgwcr
	add	x4, x3, #DEBUG_WVR
	restore_debug dbgwvr

	ldr	x21, [x2, #CPU_SYSREG_OFFSET(MDCCINT_EL1)]
	msr	mdccint_el1, x21

	ret

__save_fpsimd:
	skip_fpsimd_state x3, 1f
	save_fpsimd
1:	ret

__restore_fpsimd:
	skip_fpsimd_state x3, 1f
	restore_fpsimd
1:	ret

switch_to_guest_fpsimd:
	push	x4, lr

	mrs	x2, cptr_el2
	bic	x2, x2, #CPTR_EL2_TFP
	msr	cptr_el2, x2
	isb

	mrs	x0, tpidr_el2

	ldr	x2, [x0, #VCPU_HOST_CONTEXT]
	kern_hyp_va x2
	bl __save_fpsimd

	add	x2, x0, #VCPU_CONTEXT
	bl __restore_fpsimd

	skip_32bit_state x3, 1f
	ldr	x4, [x2, #CPU_SYSREG_OFFSET(FPEXC32_EL2)]
	msr	fpexc32_el2, x4
1:
	pop	x4, lr
	pop	x2, x3
	pop	x0, x1

	eret

/*
 * u64 __kvm_vcpu_run(struct kvm_vcpu *vcpu);
 *
 * This is the world switch. The first half of the function
 * deals with entering the guest, and anything from __kvm_vcpu_return
 * to the end of the function deals with reentering the host.
 * On the enter path, only x0 (vcpu pointer) must be preserved until
 * the last moment. On the exit path, x0 (vcpu pointer) and x1 (exception
 * code) must both be preserved until the epilogue.
 * In both cases, x2 points to the CPU context we're saving/restoring from/to.
 */
ENTRY(__kvm_vcpu_run)
	kern_hyp_va	x0
	msr	tpidr_el2, x0	// Save the vcpu register

	// Host context
	ldr	x2, [x0, #VCPU_HOST_CONTEXT]
	kern_hyp_va x2

	save_host_regs
	bl __save_sysregs

	compute_debug_state 1f
	add	x3, x0, #VCPU_HOST_DEBUG_STATE
	bl	__save_debug
1:
	activate_traps
	activate_vm

	restore_vgic_state
	restore_timer_state

	// Guest context
	add	x2, x0, #VCPU_CONTEXT

	// We must restore the 32-bit state before the sysregs, thanks
	// to Cortex-A57 erratum #852523.
	restore_guest_32bit_state
	bl __restore_sysregs

	skip_debug_state x3, 1f
	ldr	x3, [x0, #VCPU_DEBUG_PTR]
	kern_hyp_va x3
	bl	__restore_debug
1:
	restore_guest_regs

	// That's it, no more messing around.
	eret

__kvm_vcpu_return:
	// Assume x0 is the vcpu pointer, x1 the return code
	// Guest's x0-x3 are on the stack

	// Guest context
	add	x2, x0, #VCPU_CONTEXT

	save_guest_regs
	bl __save_fpsimd
	bl __save_sysregs

	skip_debug_state x3, 1f
	ldr	x3, [x0, #VCPU_DEBUG_PTR]
	kern_hyp_va x3
	bl	__save_debug
1:
	save_guest_32bit_state

	save_timer_state
	save_vgic_state

	deactivate_traps
	deactivate_vm

	// Host context
	ldr	x2, [x0, #VCPU_HOST_CONTEXT]
	kern_hyp_va x2

	bl __restore_sysregs
	bl __restore_fpsimd
	/* Clear FPSIMD and Trace trapping */
	msr     cptr_el2, xzr

	skip_debug_state x3, 1f
	// Clear the dirty flag for the next run, as all the state has
	// already been saved. Note that we nuke the whole 64bit word.
	// If we ever add more flags, we'll have to be more careful...
	str	xzr, [x0, #VCPU_DEBUG_FLAGS]
	add	x3, x0, #VCPU_HOST_DEBUG_STATE
	bl	__restore_debug
1:
	restore_host_regs

	mov	x0, x1
	ret
END(__kvm_vcpu_run)

// void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
ENTRY(__kvm_tlb_flush_vmid_ipa)
	dsb	ishst

	kern_hyp_va	x0
	ldr	x2, [x0, #KVM_VTTBR]
	msr	vttbr_el2, x2
	isb

	/*
	 * We could do so much better if we had the VA as well.
	 * Instead, we invalidate Stage-2 for this IPA, and the
	 * whole of Stage-1. Weep...
	 */
	lsr	x1, x1, #12
	tlbi	ipas2e1is, x1
	/*
	 * We have to ensure completion of the invalidation at Stage-2,
	 * since a table walk on another CPU could refill a TLB with a
	 * complete (S1 + S2) walk based on the old Stage-2 mapping if
	 * the Stage-1 invalidation happened first.
	 */
	dsb	ish
	tlbi	vmalle1is
	dsb	ish
	isb

	msr	vttbr_el2, xzr
	ret
ENDPROC(__kvm_tlb_flush_vmid_ipa)

/**
 * void __kvm_tlb_flush_vmid(struct kvm *kvm) - Flush per-VMID TLBs
 * @struct kvm *kvm - pointer to kvm structure
 *
 * Invalidates all Stage 1 and 2 TLB entries for current VMID.
 */
ENTRY(__kvm_tlb_flush_vmid)
	dsb     ishst

	kern_hyp_va     x0
	ldr     x2, [x0, #KVM_VTTBR]
	msr     vttbr_el2, x2
	isb

	tlbi    vmalls12e1is
	dsb     ish
	isb

	msr     vttbr_el2, xzr
	ret
ENDPROC(__kvm_tlb_flush_vmid)

ENTRY(__kvm_flush_vm_context)
	dsb	ishst
	tlbi	alle1is
	ic	ialluis
	dsb	ish
	ret
ENDPROC(__kvm_flush_vm_context)

__kvm_hyp_panic:
	// Guess the context by looking at VTTBR:
	// If zero, then we're already a host.
	// Otherwise restore a minimal host context before panicing.
	mrs	x0, vttbr_el2
	cbz	x0, 1f

	mrs	x0, tpidr_el2

	deactivate_traps
	deactivate_vm

	ldr	x2, [x0, #VCPU_HOST_CONTEXT]
	kern_hyp_va x2

	bl __restore_sysregs

	/*
	 * Make sure we have a valid host stack, and don't leave junk in the
	 * frame pointer that will give us a misleading host stack unwinding.
	 */
	ldr	x22, [x2, #CPU_GP_REG_OFFSET(CPU_SP_EL1)]
	msr	sp_el1, x22
	mov	x29, xzr

1:	adr	x0, __hyp_panic_str
	adr	x1, 2f
	ldp	x2, x3, [x1]
	sub	x0, x0, x2
	add	x0, x0, x3
	mrs	x1, spsr_el2
	mrs	x2, elr_el2
	mrs	x3, esr_el2
	mrs	x4, far_el2
	mrs	x5, hpfar_el2
	mrs	x6, par_el1
	mrs	x7, tpidr_el2

	mov	lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
		      PSR_MODE_EL1h)
	msr	spsr_el2, lr
	ldr	lr, =panic
	msr	elr_el2, lr
	eret

	.align	3
2:	.quad	HYP_PAGE_OFFSET
	.quad	PAGE_OFFSET
ENDPROC(__kvm_hyp_panic)

__hyp_panic_str:
	.ascii	"HYP panic:\nPS:%08x PC:%p ESR:%p\nFAR:%p HPFAR:%p PAR:%p\nVCPU:%p\n\0"

	.align	2

/*
 * u64 kvm_call_hyp(void *hypfn, ...);
 *
 * This is not really a variadic function in the classic C-way and care must
 * be taken when calling this to ensure parameters are passed in registers
 * only, since the stack will change between the caller and the callee.
 *
 * Call the function with the first argument containing a pointer to the
 * function you wish to call in Hyp mode, and subsequent arguments will be
 * passed as x0, x1, and x2 (a maximum of 3 arguments in addition to the
 * function pointer can be passed).  The function being called must be mapped
 * in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c).  Return values are
 * passed in r0 and r1.
 *
 * A function pointer with a value of 0 has a special meaning, and is
 * used to implement __hyp_get_vectors in the same way as in
 * arch/arm64/kernel/hyp_stub.S.
 */
ENTRY(kvm_call_hyp)
	hvc	#0
	ret
ENDPROC(kvm_call_hyp)

.macro invalid_vector	label, target
	.align	2
\label:
	b \target
ENDPROC(\label)
.endm

	/* None of these should ever happen */
	invalid_vector	el2t_sync_invalid, __kvm_hyp_panic
	invalid_vector	el2t_irq_invalid, __kvm_hyp_panic
	invalid_vector	el2t_fiq_invalid, __kvm_hyp_panic
	invalid_vector	el2t_error_invalid, __kvm_hyp_panic
	invalid_vector	el2h_sync_invalid, __kvm_hyp_panic
	invalid_vector	el2h_irq_invalid, __kvm_hyp_panic
	invalid_vector	el2h_fiq_invalid, __kvm_hyp_panic
	invalid_vector	el2h_error_invalid, __kvm_hyp_panic
	invalid_vector	el1_sync_invalid, __kvm_hyp_panic
	invalid_vector	el1_irq_invalid, __kvm_hyp_panic
	invalid_vector	el1_fiq_invalid, __kvm_hyp_panic
	invalid_vector	el1_error_invalid, __kvm_hyp_panic

el1_sync:					// Guest trapped into EL2
	push	x0, x1
	push	x2, x3

	mrs	x1, esr_el2
	lsr	x2, x1, #ESR_ELx_EC_SHIFT

	cmp	x2, #ESR_ELx_EC_HVC64
	b.ne	el1_trap

	mrs	x3, vttbr_el2			// If vttbr is valid, the 64bit guest
	cbnz	x3, el1_trap			// called HVC

	/* Here, we're pretty sure the host called HVC. */
	pop	x2, x3
	pop	x0, x1

	/* Check for __hyp_get_vectors */
	cbnz	x0, 1f
	mrs	x0, vbar_el2
	b	2f

1:	push	lr, xzr

	/*
	 * Compute the function address in EL2, and shuffle the parameters.
	 */
	kern_hyp_va	x0
	mov	lr, x0
	mov	x0, x1
	mov	x1, x2
	mov	x2, x3
	blr	lr

	pop	lr, xzr
2:	eret

el1_trap:
	/*
	 * x1: ESR
	 * x2: ESR_EC
	 */

	/* Guest accessed VFP/SIMD registers, save host, restore Guest */
	cmp	x2, #ESR_ELx_EC_FP_ASIMD
	b.eq	switch_to_guest_fpsimd

	cmp	x2, #ESR_ELx_EC_DABT_LOW
	mov	x0, #ESR_ELx_EC_IABT_LOW
	ccmp	x2, x0, #4, ne
	b.ne	1f		// Not an abort we care about

	/* This is an abort. Check for permission fault */
	and	x2, x1, #ESR_ELx_FSC_TYPE
	cmp	x2, #FSC_PERM
	b.ne	1f		// Not a permission fault

	/*
	 * Check for Stage-1 page table walk, which is guaranteed
	 * to give a valid HPFAR_EL2.
	 */
	tbnz	x1, #7, 1f	// S1PTW is set

	/* Preserve PAR_EL1 */
	mrs	x3, par_el1
	push	x3, xzr

	/*
	 * Permission fault, HPFAR_EL2 is invalid.
	 * Resolve the IPA the hard way using the guest VA.
	 * Stage-1 translation already validated the memory access rights.
	 * As such, we can use the EL1 translation regime, and don't have
	 * to distinguish between EL0 and EL1 access.
	 */
	mrs	x2, far_el2
	at	s1e1r, x2
	isb

	/* Read result */
	mrs	x3, par_el1
	pop	x0, xzr			// Restore PAR_EL1 from the stack
	msr	par_el1, x0
	tbnz	x3, #0, 3f		// Bail out if we failed the translation
	ubfx	x3, x3, #12, #36	// Extract IPA
	lsl	x3, x3, #4		// and present it like HPFAR
	b	2f

1:	mrs	x3, hpfar_el2
	mrs	x2, far_el2

2:	mrs	x0, tpidr_el2
	str	w1, [x0, #VCPU_ESR_EL2]
	str	x2, [x0, #VCPU_FAR_EL2]
	str	x3, [x0, #VCPU_HPFAR_EL2]

	mov	x1, #ARM_EXCEPTION_TRAP
	b	__kvm_vcpu_return

	/*
	 * Translation failed. Just return to the guest and
	 * let it fault again. Another CPU is probably playing
	 * behind our back.
	 */
3:	pop	x2, x3
	pop	x0, x1

	eret

el1_irq:
	push	x0, x1
	push	x2, x3
	mrs	x0, tpidr_el2
	mov	x1, #ARM_EXCEPTION_IRQ
	b	__kvm_vcpu_return

	.ltorg

	.align 11

ENTRY(__kvm_hyp_vector)
	ventry	el2t_sync_invalid		// Synchronous EL2t
	ventry	el2t_irq_invalid		// IRQ EL2t
	ventry	el2t_fiq_invalid		// FIQ EL2t
	ventry	el2t_error_invalid		// Error EL2t

	ventry	el2h_sync_invalid		// Synchronous EL2h
	ventry	el2h_irq_invalid		// IRQ EL2h
	ventry	el2h_fiq_invalid		// FIQ EL2h
	ventry	el2h_error_invalid		// Error EL2h

	ventry	el1_sync			// Synchronous 64-bit EL1
	ventry	el1_irq				// IRQ 64-bit EL1
	ventry	el1_fiq_invalid			// FIQ 64-bit EL1
	ventry	el1_error_invalid		// Error 64-bit EL1

	ventry	el1_sync			// Synchronous 32-bit EL1
	ventry	el1_irq				// IRQ 32-bit EL1
	ventry	el1_fiq_invalid			// FIQ 32-bit EL1
	ventry	el1_error_invalid		// Error 32-bit EL1
ENDPROC(__kvm_hyp_vector)


ENTRY(__kvm_get_mdcr_el2)
	mrs	x0, mdcr_el2
	ret
ENDPROC(__kvm_get_mdcr_el2)

	.popsection
OpenPOWER on IntegriCloud