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1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * KVM/MIPS: Instruction/Exception emulation
7 *
8 * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
9 * Authors: Sanjay Lal <sanjayl@kymasys.com>
10 */
11
12#include <linux/errno.h>
13#include <linux/err.h>
14#include <linux/ktime.h>
15#include <linux/kvm_host.h>
16#include <linux/vmalloc.h>
17#include <linux/fs.h>
18#include <linux/bootmem.h>
19#include <linux/random.h>
20#include <asm/page.h>
21#include <asm/cacheflush.h>
22#include <asm/cacheops.h>
23#include <asm/cpu-info.h>
24#include <asm/mmu_context.h>
25#include <asm/tlbflush.h>
26#include <asm/inst.h>
27
28#undef CONFIG_MIPS_MT
29#include <asm/r4kcache.h>
30#define CONFIG_MIPS_MT
31
32#include "interrupt.h"
33#include "commpage.h"
34
35#include "trace.h"
36
37/*
38 * Compute the return address and do emulate branch simulation, if required.
39 * This function should be called only in branch delay slot active.
40 */
41unsigned long kvm_compute_return_epc(struct kvm_vcpu *vcpu,
42 unsigned long instpc)
43{
44 unsigned int dspcontrol;
45 union mips_instruction insn;
46 struct kvm_vcpu_arch *arch = &vcpu->arch;
47 long epc = instpc;
48 long nextpc = KVM_INVALID_INST;
49
50 if (epc & 3)
51 goto unaligned;
52
53 /* Read the instruction */
54 insn.word = kvm_get_inst((u32 *) epc, vcpu);
55
56 if (insn.word == KVM_INVALID_INST)
57 return KVM_INVALID_INST;
58
59 switch (insn.i_format.opcode) {
60 /* jr and jalr are in r_format format. */
61 case spec_op:
62 switch (insn.r_format.func) {
63 case jalr_op:
64 arch->gprs[insn.r_format.rd] = epc + 8;
65 /* Fall through */
66 case jr_op:
67 nextpc = arch->gprs[insn.r_format.rs];
68 break;
69 }
70 break;
71
72 /*
73 * This group contains:
74 * bltz_op, bgez_op, bltzl_op, bgezl_op,
75 * bltzal_op, bgezal_op, bltzall_op, bgezall_op.
76 */
77 case bcond_op:
78 switch (insn.i_format.rt) {
79 case bltz_op:
80 case bltzl_op:
81 if ((long)arch->gprs[insn.i_format.rs] < 0)
82 epc = epc + 4 + (insn.i_format.simmediate << 2);
83 else
84 epc += 8;
85 nextpc = epc;
86 break;
87
88 case bgez_op:
89 case bgezl_op:
90 if ((long)arch->gprs[insn.i_format.rs] >= 0)
91 epc = epc + 4 + (insn.i_format.simmediate << 2);
92 else
93 epc += 8;
94 nextpc = epc;
95 break;
96
97 case bltzal_op:
98 case bltzall_op:
99 arch->gprs[31] = epc + 8;
100 if ((long)arch->gprs[insn.i_format.rs] < 0)
101 epc = epc + 4 + (insn.i_format.simmediate << 2);
102 else
103 epc += 8;
104 nextpc = epc;
105 break;
106
107 case bgezal_op:
108 case bgezall_op:
109 arch->gprs[31] = epc + 8;
110 if ((long)arch->gprs[insn.i_format.rs] >= 0)
111 epc = epc + 4 + (insn.i_format.simmediate << 2);
112 else
113 epc += 8;
114 nextpc = epc;
115 break;
116 case bposge32_op:
117 if (!cpu_has_dsp)
118 goto sigill;
119
120 dspcontrol = rddsp(0x01);
121
122 if (dspcontrol >= 32)
123 epc = epc + 4 + (insn.i_format.simmediate << 2);
124 else
125 epc += 8;
126 nextpc = epc;
127 break;
128 }
129 break;
130
131 /* These are unconditional and in j_format. */
132 case jal_op:
133 arch->gprs[31] = instpc + 8;
134 case j_op:
135 epc += 4;
136 epc >>= 28;
137 epc <<= 28;
138 epc |= (insn.j_format.target << 2);
139 nextpc = epc;
140 break;
141
142 /* These are conditional and in i_format. */
143 case beq_op:
144 case beql_op:
145 if (arch->gprs[insn.i_format.rs] ==
146 arch->gprs[insn.i_format.rt])
147 epc = epc + 4 + (insn.i_format.simmediate << 2);
148 else
149 epc += 8;
150 nextpc = epc;
151 break;
152
153 case bne_op:
154 case bnel_op:
155 if (arch->gprs[insn.i_format.rs] !=
156 arch->gprs[insn.i_format.rt])
157 epc = epc + 4 + (insn.i_format.simmediate << 2);
158 else
159 epc += 8;
160 nextpc = epc;
161 break;
162
163 case blez_op: /* POP06 */
164#ifndef CONFIG_CPU_MIPSR6
165 case blezl_op: /* removed in R6 */
166#endif
167 if (insn.i_format.rt != 0)
168 goto compact_branch;
169 if ((long)arch->gprs[insn.i_format.rs] <= 0)
170 epc = epc + 4 + (insn.i_format.simmediate << 2);
171 else
172 epc += 8;
173 nextpc = epc;
174 break;
175
176 case bgtz_op: /* POP07 */
177#ifndef CONFIG_CPU_MIPSR6
178 case bgtzl_op: /* removed in R6 */
179#endif
180 if (insn.i_format.rt != 0)
181 goto compact_branch;
182 if ((long)arch->gprs[insn.i_format.rs] > 0)
183 epc = epc + 4 + (insn.i_format.simmediate << 2);
184 else
185 epc += 8;
186 nextpc = epc;
187 break;
188
189 /* And now the FPA/cp1 branch instructions. */
190 case cop1_op:
191 kvm_err("%s: unsupported cop1_op\n", __func__);
192 break;
193
194#ifdef CONFIG_CPU_MIPSR6
195 /* R6 added the following compact branches with forbidden slots */
196 case blezl_op: /* POP26 */
197 case bgtzl_op: /* POP27 */
198 /* only rt == 0 isn't compact branch */
199 if (insn.i_format.rt != 0)
200 goto compact_branch;
201 break;
202 case pop10_op:
203 case pop30_op:
204 /* only rs == rt == 0 is reserved, rest are compact branches */
205 if (insn.i_format.rs != 0 || insn.i_format.rt != 0)
206 goto compact_branch;
207 break;
208 case pop66_op:
209 case pop76_op:
210 /* only rs == 0 isn't compact branch */
211 if (insn.i_format.rs != 0)
212 goto compact_branch;
213 break;
214compact_branch:
215 /*
216 * If we've hit an exception on the forbidden slot, then
217 * the branch must not have been taken.
218 */
219 epc += 8;
220 nextpc = epc;
221 break;
222#else
223compact_branch:
224 /* Compact branches not supported before R6 */
225 break;
226#endif
227 }
228
229 return nextpc;
230
231unaligned:
232 kvm_err("%s: unaligned epc\n", __func__);
233 return nextpc;
234
235sigill:
236 kvm_err("%s: DSP branch but not DSP ASE\n", __func__);
237 return nextpc;
238}
239
240enum emulation_result update_pc(struct kvm_vcpu *vcpu, u32 cause)
241{
242 unsigned long branch_pc;
243 enum emulation_result er = EMULATE_DONE;
244
245 if (cause & CAUSEF_BD) {
246 branch_pc = kvm_compute_return_epc(vcpu, vcpu->arch.pc);
247 if (branch_pc == KVM_INVALID_INST) {
248 er = EMULATE_FAIL;
249 } else {
250 vcpu->arch.pc = branch_pc;
251 kvm_debug("BD update_pc(): New PC: %#lx\n",
252 vcpu->arch.pc);
253 }
254 } else
255 vcpu->arch.pc += 4;
256
257 kvm_debug("update_pc(): New PC: %#lx\n", vcpu->arch.pc);
258
259 return er;
260}
261
262/**
263 * kvm_mips_count_disabled() - Find whether the CP0_Count timer is disabled.
264 * @vcpu: Virtual CPU.
265 *
266 * Returns: 1 if the CP0_Count timer is disabled by either the guest
267 * CP0_Cause.DC bit or the count_ctl.DC bit.
268 * 0 otherwise (in which case CP0_Count timer is running).
269 */
270static inline int kvm_mips_count_disabled(struct kvm_vcpu *vcpu)
271{
272 struct mips_coproc *cop0 = vcpu->arch.cop0;
273
274 return (vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) ||
275 (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC);
276}
277
278/**
279 * kvm_mips_ktime_to_count() - Scale ktime_t to a 32-bit count.
280 *
281 * Caches the dynamic nanosecond bias in vcpu->arch.count_dyn_bias.
282 *
283 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
284 */
285static u32 kvm_mips_ktime_to_count(struct kvm_vcpu *vcpu, ktime_t now)
286{
287 s64 now_ns, periods;
288 u64 delta;
289
290 now_ns = ktime_to_ns(now);
291 delta = now_ns + vcpu->arch.count_dyn_bias;
292
293 if (delta >= vcpu->arch.count_period) {
294 /* If delta is out of safe range the bias needs adjusting */
295 periods = div64_s64(now_ns, vcpu->arch.count_period);
296 vcpu->arch.count_dyn_bias = -periods * vcpu->arch.count_period;
297 /* Recalculate delta with new bias */
298 delta = now_ns + vcpu->arch.count_dyn_bias;
299 }
300
301 /*
302 * We've ensured that:
303 * delta < count_period
304 *
305 * Therefore the intermediate delta*count_hz will never overflow since
306 * at the boundary condition:
307 * delta = count_period
308 * delta = NSEC_PER_SEC * 2^32 / count_hz
309 * delta * count_hz = NSEC_PER_SEC * 2^32
310 */
311 return div_u64(delta * vcpu->arch.count_hz, NSEC_PER_SEC);
312}
313
314/**
315 * kvm_mips_count_time() - Get effective current time.
316 * @vcpu: Virtual CPU.
317 *
318 * Get effective monotonic ktime. This is usually a straightforward ktime_get(),
319 * except when the master disable bit is set in count_ctl, in which case it is
320 * count_resume, i.e. the time that the count was disabled.
321 *
322 * Returns: Effective monotonic ktime for CP0_Count.
323 */
324static inline ktime_t kvm_mips_count_time(struct kvm_vcpu *vcpu)
325{
326 if (unlikely(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC))
327 return vcpu->arch.count_resume;
328
329 return ktime_get();
330}
331
332/**
333 * kvm_mips_read_count_running() - Read the current count value as if running.
334 * @vcpu: Virtual CPU.
335 * @now: Kernel time to read CP0_Count at.
336 *
337 * Returns the current guest CP0_Count register at time @now and handles if the
338 * timer interrupt is pending and hasn't been handled yet.
339 *
340 * Returns: The current value of the guest CP0_Count register.
341 */
342static u32 kvm_mips_read_count_running(struct kvm_vcpu *vcpu, ktime_t now)
343{
344 struct mips_coproc *cop0 = vcpu->arch.cop0;
345 ktime_t expires, threshold;
346 u32 count, compare;
347 int running;
348
349 /* Calculate the biased and scaled guest CP0_Count */
350 count = vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now);
351 compare = kvm_read_c0_guest_compare(cop0);
352
353 /*
354 * Find whether CP0_Count has reached the closest timer interrupt. If
355 * not, we shouldn't inject it.
356 */
357 if ((s32)(count - compare) < 0)
358 return count;
359
360 /*
361 * The CP0_Count we're going to return has already reached the closest
362 * timer interrupt. Quickly check if it really is a new interrupt by
363 * looking at whether the interval until the hrtimer expiry time is
364 * less than 1/4 of the timer period.
365 */
366 expires = hrtimer_get_expires(&vcpu->arch.comparecount_timer);
367 threshold = ktime_add_ns(now, vcpu->arch.count_period / 4);
368 if (ktime_before(expires, threshold)) {
369 /*
370 * Cancel it while we handle it so there's no chance of
371 * interference with the timeout handler.
372 */
373 running = hrtimer_cancel(&vcpu->arch.comparecount_timer);
374
375 /* Nothing should be waiting on the timeout */
376 kvm_mips_callbacks->queue_timer_int(vcpu);
377
378 /*
379 * Restart the timer if it was running based on the expiry time
380 * we read, so that we don't push it back 2 periods.
381 */
382 if (running) {
383 expires = ktime_add_ns(expires,
384 vcpu->arch.count_period);
385 hrtimer_start(&vcpu->arch.comparecount_timer, expires,
386 HRTIMER_MODE_ABS);
387 }
388 }
389
390 return count;
391}
392
393/**
394 * kvm_mips_read_count() - Read the current count value.
395 * @vcpu: Virtual CPU.
396 *
397 * Read the current guest CP0_Count value, taking into account whether the timer
398 * is stopped.
399 *
400 * Returns: The current guest CP0_Count value.
401 */
402u32 kvm_mips_read_count(struct kvm_vcpu *vcpu)
403{
404 struct mips_coproc *cop0 = vcpu->arch.cop0;
405
406 /* If count disabled just read static copy of count */
407 if (kvm_mips_count_disabled(vcpu))
408 return kvm_read_c0_guest_count(cop0);
409
410 return kvm_mips_read_count_running(vcpu, ktime_get());
411}
412
413/**
414 * kvm_mips_freeze_hrtimer() - Safely stop the hrtimer.
415 * @vcpu: Virtual CPU.
416 * @count: Output pointer for CP0_Count value at point of freeze.
417 *
418 * Freeze the hrtimer safely and return both the ktime and the CP0_Count value
419 * at the point it was frozen. It is guaranteed that any pending interrupts at
420 * the point it was frozen are handled, and none after that point.
421 *
422 * This is useful where the time/CP0_Count is needed in the calculation of the
423 * new parameters.
424 *
425 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
426 *
427 * Returns: The ktime at the point of freeze.
428 */
429static ktime_t kvm_mips_freeze_hrtimer(struct kvm_vcpu *vcpu, u32 *count)
430{
431 ktime_t now;
432
433 /* stop hrtimer before finding time */
434 hrtimer_cancel(&vcpu->arch.comparecount_timer);
435 now = ktime_get();
436
437 /* find count at this point and handle pending hrtimer */
438 *count = kvm_mips_read_count_running(vcpu, now);
439
440 return now;
441}
442
443/**
444 * kvm_mips_resume_hrtimer() - Resume hrtimer, updating expiry.
445 * @vcpu: Virtual CPU.
446 * @now: ktime at point of resume.
447 * @count: CP0_Count at point of resume.
448 *
449 * Resumes the timer and updates the timer expiry based on @now and @count.
450 * This can be used in conjunction with kvm_mips_freeze_timer() when timer
451 * parameters need to be changed.
452 *
453 * It is guaranteed that a timer interrupt immediately after resume will be
454 * handled, but not if CP_Compare is exactly at @count. That case is already
455 * handled by kvm_mips_freeze_timer().
456 *
457 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
458 */
459static void kvm_mips_resume_hrtimer(struct kvm_vcpu *vcpu,
460 ktime_t now, u32 count)
461{
462 struct mips_coproc *cop0 = vcpu->arch.cop0;
463 u32 compare;
464 u64 delta;
465 ktime_t expire;
466
467 /* Calculate timeout (wrap 0 to 2^32) */
468 compare = kvm_read_c0_guest_compare(cop0);
469 delta = (u64)(u32)(compare - count - 1) + 1;
470 delta = div_u64(delta * NSEC_PER_SEC, vcpu->arch.count_hz);
471 expire = ktime_add_ns(now, delta);
472
473 /* Update hrtimer to use new timeout */
474 hrtimer_cancel(&vcpu->arch.comparecount_timer);
475 hrtimer_start(&vcpu->arch.comparecount_timer, expire, HRTIMER_MODE_ABS);
476}
477
478/**
479 * kvm_mips_write_count() - Modify the count and update timer.
480 * @vcpu: Virtual CPU.
481 * @count: Guest CP0_Count value to set.
482 *
483 * Sets the CP0_Count value and updates the timer accordingly.
484 */
485void kvm_mips_write_count(struct kvm_vcpu *vcpu, u32 count)
486{
487 struct mips_coproc *cop0 = vcpu->arch.cop0;
488 ktime_t now;
489
490 /* Calculate bias */
491 now = kvm_mips_count_time(vcpu);
492 vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now);
493
494 if (kvm_mips_count_disabled(vcpu))
495 /* The timer's disabled, adjust the static count */
496 kvm_write_c0_guest_count(cop0, count);
497 else
498 /* Update timeout */
499 kvm_mips_resume_hrtimer(vcpu, now, count);
500}
501
502/**
503 * kvm_mips_init_count() - Initialise timer.
504 * @vcpu: Virtual CPU.
505 *
506 * Initialise the timer to a sensible frequency, namely 100MHz, zero it, and set
507 * it going if it's enabled.
508 */
509void kvm_mips_init_count(struct kvm_vcpu *vcpu)
510{
511 /* 100 MHz */
512 vcpu->arch.count_hz = 100*1000*1000;
513 vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32,
514 vcpu->arch.count_hz);
515 vcpu->arch.count_dyn_bias = 0;
516
517 /* Starting at 0 */
518 kvm_mips_write_count(vcpu, 0);
519}
520
521/**
522 * kvm_mips_set_count_hz() - Update the frequency of the timer.
523 * @vcpu: Virtual CPU.
524 * @count_hz: Frequency of CP0_Count timer in Hz.
525 *
526 * Change the frequency of the CP0_Count timer. This is done atomically so that
527 * CP0_Count is continuous and no timer interrupt is lost.
528 *
529 * Returns: -EINVAL if @count_hz is out of range.
530 * 0 on success.
531 */
532int kvm_mips_set_count_hz(struct kvm_vcpu *vcpu, s64 count_hz)
533{
534 struct mips_coproc *cop0 = vcpu->arch.cop0;
535 int dc;
536 ktime_t now;
537 u32 count;
538
539 /* ensure the frequency is in a sensible range... */
540 if (count_hz <= 0 || count_hz > NSEC_PER_SEC)
541 return -EINVAL;
542 /* ... and has actually changed */
543 if (vcpu->arch.count_hz == count_hz)
544 return 0;
545
546 /* Safely freeze timer so we can keep it continuous */
547 dc = kvm_mips_count_disabled(vcpu);
548 if (dc) {
549 now = kvm_mips_count_time(vcpu);
550 count = kvm_read_c0_guest_count(cop0);
551 } else {
552 now = kvm_mips_freeze_hrtimer(vcpu, &count);
553 }
554
555 /* Update the frequency */
556 vcpu->arch.count_hz = count_hz;
557 vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32, count_hz);
558 vcpu->arch.count_dyn_bias = 0;
559
560 /* Calculate adjusted bias so dynamic count is unchanged */
561 vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now);
562
563 /* Update and resume hrtimer */
564 if (!dc)
565 kvm_mips_resume_hrtimer(vcpu, now, count);
566 return 0;
567}
568
569/**
570 * kvm_mips_write_compare() - Modify compare and update timer.
571 * @vcpu: Virtual CPU.
572 * @compare: New CP0_Compare value.
573 * @ack: Whether to acknowledge timer interrupt.
574 *
575 * Update CP0_Compare to a new value and update the timeout.
576 * If @ack, atomically acknowledge any pending timer interrupt, otherwise ensure
577 * any pending timer interrupt is preserved.
578 */
579void kvm_mips_write_compare(struct kvm_vcpu *vcpu, u32 compare, bool ack)
580{
581 struct mips_coproc *cop0 = vcpu->arch.cop0;
582 int dc;
583 u32 old_compare = kvm_read_c0_guest_compare(cop0);
584 ktime_t now;
585 u32 count;
586
587 /* if unchanged, must just be an ack */
588 if (old_compare == compare) {
589 if (!ack)
590 return;
591 kvm_mips_callbacks->dequeue_timer_int(vcpu);
592 kvm_write_c0_guest_compare(cop0, compare);
593 return;
594 }
595
596 /* freeze_hrtimer() takes care of timer interrupts <= count */
597 dc = kvm_mips_count_disabled(vcpu);
598 if (!dc)
599 now = kvm_mips_freeze_hrtimer(vcpu, &count);
600
601 if (ack)
602 kvm_mips_callbacks->dequeue_timer_int(vcpu);
603
604 kvm_write_c0_guest_compare(cop0, compare);
605
606 /* resume_hrtimer() takes care of timer interrupts > count */
607 if (!dc)
608 kvm_mips_resume_hrtimer(vcpu, now, count);
609}
610
611/**
612 * kvm_mips_count_disable() - Disable count.
613 * @vcpu: Virtual CPU.
614 *
615 * Disable the CP0_Count timer. A timer interrupt on or before the final stop
616 * time will be handled but not after.
617 *
618 * Assumes CP0_Count was previously enabled but now Guest.CP0_Cause.DC or
619 * count_ctl.DC has been set (count disabled).
620 *
621 * Returns: The time that the timer was stopped.
622 */
623static ktime_t kvm_mips_count_disable(struct kvm_vcpu *vcpu)
624{
625 struct mips_coproc *cop0 = vcpu->arch.cop0;
626 u32 count;
627 ktime_t now;
628
629 /* Stop hrtimer */
630 hrtimer_cancel(&vcpu->arch.comparecount_timer);
631
632 /* Set the static count from the dynamic count, handling pending TI */
633 now = ktime_get();
634 count = kvm_mips_read_count_running(vcpu, now);
635 kvm_write_c0_guest_count(cop0, count);
636
637 return now;
638}
639
640/**
641 * kvm_mips_count_disable_cause() - Disable count using CP0_Cause.DC.
642 * @vcpu: Virtual CPU.
643 *
644 * Disable the CP0_Count timer and set CP0_Cause.DC. A timer interrupt on or
645 * before the final stop time will be handled if the timer isn't disabled by
646 * count_ctl.DC, but not after.
647 *
648 * Assumes CP0_Cause.DC is clear (count enabled).
649 */
650void kvm_mips_count_disable_cause(struct kvm_vcpu *vcpu)
651{
652 struct mips_coproc *cop0 = vcpu->arch.cop0;
653
654 kvm_set_c0_guest_cause(cop0, CAUSEF_DC);
655 if (!(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC))
656 kvm_mips_count_disable(vcpu);
657}
658
659/**
660 * kvm_mips_count_enable_cause() - Enable count using CP0_Cause.DC.
661 * @vcpu: Virtual CPU.
662 *
663 * Enable the CP0_Count timer and clear CP0_Cause.DC. A timer interrupt after
664 * the start time will be handled if the timer isn't disabled by count_ctl.DC,
665 * potentially before even returning, so the caller should be careful with
666 * ordering of CP0_Cause modifications so as not to lose it.
667 *
668 * Assumes CP0_Cause.DC is set (count disabled).
669 */
670void kvm_mips_count_enable_cause(struct kvm_vcpu *vcpu)
671{
672 struct mips_coproc *cop0 = vcpu->arch.cop0;
673 u32 count;
674
675 kvm_clear_c0_guest_cause(cop0, CAUSEF_DC);
676
677 /*
678 * Set the dynamic count to match the static count.
679 * This starts the hrtimer if count_ctl.DC allows it.
680 * Otherwise it conveniently updates the biases.
681 */
682 count = kvm_read_c0_guest_count(cop0);
683 kvm_mips_write_count(vcpu, count);
684}
685
686/**
687 * kvm_mips_set_count_ctl() - Update the count control KVM register.
688 * @vcpu: Virtual CPU.
689 * @count_ctl: Count control register new value.
690 *
691 * Set the count control KVM register. The timer is updated accordingly.
692 *
693 * Returns: -EINVAL if reserved bits are set.
694 * 0 on success.
695 */
696int kvm_mips_set_count_ctl(struct kvm_vcpu *vcpu, s64 count_ctl)
697{
698 struct mips_coproc *cop0 = vcpu->arch.cop0;
699 s64 changed = count_ctl ^ vcpu->arch.count_ctl;
700 s64 delta;
701 ktime_t expire, now;
702 u32 count, compare;
703
704 /* Only allow defined bits to be changed */
705 if (changed & ~(s64)(KVM_REG_MIPS_COUNT_CTL_DC))
706 return -EINVAL;
707
708 /* Apply new value */
709 vcpu->arch.count_ctl = count_ctl;
710
711 /* Master CP0_Count disable */
712 if (changed & KVM_REG_MIPS_COUNT_CTL_DC) {
713 /* Is CP0_Cause.DC already disabling CP0_Count? */
714 if (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC) {
715 if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC)
716 /* Just record the current time */
717 vcpu->arch.count_resume = ktime_get();
718 } else if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) {
719 /* disable timer and record current time */
720 vcpu->arch.count_resume = kvm_mips_count_disable(vcpu);
721 } else {
722 /*
723 * Calculate timeout relative to static count at resume
724 * time (wrap 0 to 2^32).
725 */
726 count = kvm_read_c0_guest_count(cop0);
727 compare = kvm_read_c0_guest_compare(cop0);
728 delta = (u64)(u32)(compare - count - 1) + 1;
729 delta = div_u64(delta * NSEC_PER_SEC,
730 vcpu->arch.count_hz);
731 expire = ktime_add_ns(vcpu->arch.count_resume, delta);
732
733 /* Handle pending interrupt */
734 now = ktime_get();
735 if (ktime_compare(now, expire) >= 0)
736 /* Nothing should be waiting on the timeout */
737 kvm_mips_callbacks->queue_timer_int(vcpu);
738
739 /* Resume hrtimer without changing bias */
740 count = kvm_mips_read_count_running(vcpu, now);
741 kvm_mips_resume_hrtimer(vcpu, now, count);
742 }
743 }
744
745 return 0;
746}
747
748/**
749 * kvm_mips_set_count_resume() - Update the count resume KVM register.
750 * @vcpu: Virtual CPU.
751 * @count_resume: Count resume register new value.
752 *
753 * Set the count resume KVM register.
754 *
755 * Returns: -EINVAL if out of valid range (0..now).
756 * 0 on success.
757 */
758int kvm_mips_set_count_resume(struct kvm_vcpu *vcpu, s64 count_resume)
759{
760 /*
761 * It doesn't make sense for the resume time to be in the future, as it
762 * would be possible for the next interrupt to be more than a full
763 * period in the future.
764 */
765 if (count_resume < 0 || count_resume > ktime_to_ns(ktime_get()))
766 return -EINVAL;
767
768 vcpu->arch.count_resume = ns_to_ktime(count_resume);
769 return 0;
770}
771
772/**
773 * kvm_mips_count_timeout() - Push timer forward on timeout.
774 * @vcpu: Virtual CPU.
775 *
776 * Handle an hrtimer event by push the hrtimer forward a period.
777 *
778 * Returns: The hrtimer_restart value to return to the hrtimer subsystem.
779 */
780enum hrtimer_restart kvm_mips_count_timeout(struct kvm_vcpu *vcpu)
781{
782 /* Add the Count period to the current expiry time */
783 hrtimer_add_expires_ns(&vcpu->arch.comparecount_timer,
784 vcpu->arch.count_period);
785 return HRTIMER_RESTART;
786}
787
788enum emulation_result kvm_mips_emul_eret(struct kvm_vcpu *vcpu)
789{
790 struct mips_coproc *cop0 = vcpu->arch.cop0;
791 enum emulation_result er = EMULATE_DONE;
792
793 if (kvm_read_c0_guest_status(cop0) & ST0_ERL) {
794 kvm_clear_c0_guest_status(cop0, ST0_ERL);
795 vcpu->arch.pc = kvm_read_c0_guest_errorepc(cop0);
796 } else if (kvm_read_c0_guest_status(cop0) & ST0_EXL) {
797 kvm_debug("[%#lx] ERET to %#lx\n", vcpu->arch.pc,
798 kvm_read_c0_guest_epc(cop0));
799 kvm_clear_c0_guest_status(cop0, ST0_EXL);
800 vcpu->arch.pc = kvm_read_c0_guest_epc(cop0);
801
802 } else {
803 kvm_err("[%#lx] ERET when MIPS_SR_EXL|MIPS_SR_ERL == 0\n",
804 vcpu->arch.pc);
805 er = EMULATE_FAIL;
806 }
807
808 return er;
809}
810
811enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
812{
813 kvm_debug("[%#lx] !!!WAIT!!! (%#lx)\n", vcpu->arch.pc,
814 vcpu->arch.pending_exceptions);
815
816 ++vcpu->stat.wait_exits;
817 trace_kvm_exit(vcpu, KVM_TRACE_EXIT_WAIT);
818 if (!vcpu->arch.pending_exceptions) {
819 vcpu->arch.wait = 1;
820 kvm_vcpu_block(vcpu);
821
822 /*
823 * We we are runnable, then definitely go off to user space to
824 * check if any I/O interrupts are pending.
825 */
826 if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
827 clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
828 vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
829 }
830 }
831
832 return EMULATE_DONE;
833}
834
835/*
836 * XXXKYMA: Linux doesn't seem to use TLBR, return EMULATE_FAIL for now so that
837 * we can catch this, if things ever change
838 */
839enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu)
840{
841 struct mips_coproc *cop0 = vcpu->arch.cop0;
842 unsigned long pc = vcpu->arch.pc;
843
844 kvm_err("[%#lx] COP0_TLBR [%ld]\n", pc, kvm_read_c0_guest_index(cop0));
845 return EMULATE_FAIL;
846}
847
848/**
849 * kvm_mips_invalidate_guest_tlb() - Indicates a change in guest MMU map.
850 * @vcpu: VCPU with changed mappings.
851 * @tlb: TLB entry being removed.
852 *
853 * This is called to indicate a single change in guest MMU mappings, so that we
854 * can arrange TLB flushes on this and other CPUs.
855 */
856static void kvm_mips_invalidate_guest_tlb(struct kvm_vcpu *vcpu,
857 struct kvm_mips_tlb *tlb)
858{
859 int cpu, i;
860 bool user;
861
862 /* No need to flush for entries which are already invalid */
863 if (!((tlb->tlb_lo[0] | tlb->tlb_lo[1]) & ENTRYLO_V))
864 return;
865 /* User address space doesn't need flushing for KSeg2/3 changes */
866 user = tlb->tlb_hi < KVM_GUEST_KSEG0;
867
868 preempt_disable();
869
870 /*
871 * Probe the shadow host TLB for the entry being overwritten, if one
872 * matches, invalidate it
873 */
874 kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
875
876 /* Invalidate the whole ASID on other CPUs */
877 cpu = smp_processor_id();
878 for_each_possible_cpu(i) {
879 if (i == cpu)
880 continue;
881 if (user)
882 vcpu->arch.guest_user_asid[i] = 0;
883 vcpu->arch.guest_kernel_asid[i] = 0;
884 }
885
886 preempt_enable();
887}
888
889/* Write Guest TLB Entry @ Index */
890enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu)
891{
892 struct mips_coproc *cop0 = vcpu->arch.cop0;
893 int index = kvm_read_c0_guest_index(cop0);
894 struct kvm_mips_tlb *tlb = NULL;
895 unsigned long pc = vcpu->arch.pc;
896
897 if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) {
898 kvm_debug("%s: illegal index: %d\n", __func__, index);
899 kvm_debug("[%#lx] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
900 pc, index, kvm_read_c0_guest_entryhi(cop0),
901 kvm_read_c0_guest_entrylo0(cop0),
902 kvm_read_c0_guest_entrylo1(cop0),
903 kvm_read_c0_guest_pagemask(cop0));
904 index = (index & ~0x80000000) % KVM_MIPS_GUEST_TLB_SIZE;
905 }
906
907 tlb = &vcpu->arch.guest_tlb[index];
908
909 kvm_mips_invalidate_guest_tlb(vcpu, tlb);
910
911 tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
912 tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
913 tlb->tlb_lo[0] = kvm_read_c0_guest_entrylo0(cop0);
914 tlb->tlb_lo[1] = kvm_read_c0_guest_entrylo1(cop0);
915
916 kvm_debug("[%#lx] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
917 pc, index, kvm_read_c0_guest_entryhi(cop0),
918 kvm_read_c0_guest_entrylo0(cop0),
919 kvm_read_c0_guest_entrylo1(cop0),
920 kvm_read_c0_guest_pagemask(cop0));
921
922 return EMULATE_DONE;
923}
924
925/* Write Guest TLB Entry @ Random Index */
926enum emulation_result kvm_mips_emul_tlbwr(struct kvm_vcpu *vcpu)
927{
928 struct mips_coproc *cop0 = vcpu->arch.cop0;
929 struct kvm_mips_tlb *tlb = NULL;
930 unsigned long pc = vcpu->arch.pc;
931 int index;
932
933 get_random_bytes(&index, sizeof(index));
934 index &= (KVM_MIPS_GUEST_TLB_SIZE - 1);
935
936 tlb = &vcpu->arch.guest_tlb[index];
937
938 kvm_mips_invalidate_guest_tlb(vcpu, tlb);
939
940 tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
941 tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
942 tlb->tlb_lo[0] = kvm_read_c0_guest_entrylo0(cop0);
943 tlb->tlb_lo[1] = kvm_read_c0_guest_entrylo1(cop0);
944
945 kvm_debug("[%#lx] COP0_TLBWR[%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx)\n",
946 pc, index, kvm_read_c0_guest_entryhi(cop0),
947 kvm_read_c0_guest_entrylo0(cop0),
948 kvm_read_c0_guest_entrylo1(cop0));
949
950 return EMULATE_DONE;
951}
952
953enum emulation_result kvm_mips_emul_tlbp(struct kvm_vcpu *vcpu)
954{
955 struct mips_coproc *cop0 = vcpu->arch.cop0;
956 long entryhi = kvm_read_c0_guest_entryhi(cop0);
957 unsigned long pc = vcpu->arch.pc;
958 int index = -1;
959
960 index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
961
962 kvm_write_c0_guest_index(cop0, index);
963
964 kvm_debug("[%#lx] COP0_TLBP (entryhi: %#lx), index: %d\n", pc, entryhi,
965 index);
966
967 return EMULATE_DONE;
968}
969
970/**
971 * kvm_mips_config1_wrmask() - Find mask of writable bits in guest Config1
972 * @vcpu: Virtual CPU.
973 *
974 * Finds the mask of bits which are writable in the guest's Config1 CP0
975 * register, by userland (currently read-only to the guest).
976 */
977unsigned int kvm_mips_config1_wrmask(struct kvm_vcpu *vcpu)
978{
979 unsigned int mask = 0;
980
981 /* Permit FPU to be present if FPU is supported */
982 if (kvm_mips_guest_can_have_fpu(&vcpu->arch))
983 mask |= MIPS_CONF1_FP;
984
985 return mask;
986}
987
988/**
989 * kvm_mips_config3_wrmask() - Find mask of writable bits in guest Config3
990 * @vcpu: Virtual CPU.
991 *
992 * Finds the mask of bits which are writable in the guest's Config3 CP0
993 * register, by userland (currently read-only to the guest).
994 */
995unsigned int kvm_mips_config3_wrmask(struct kvm_vcpu *vcpu)
996{
997 /* Config4 and ULRI are optional */
998 unsigned int mask = MIPS_CONF_M | MIPS_CONF3_ULRI;
999
1000 /* Permit MSA to be present if MSA is supported */
1001 if (kvm_mips_guest_can_have_msa(&vcpu->arch))
1002 mask |= MIPS_CONF3_MSA;
1003
1004 return mask;
1005}
1006
1007/**
1008 * kvm_mips_config4_wrmask() - Find mask of writable bits in guest Config4
1009 * @vcpu: Virtual CPU.
1010 *
1011 * Finds the mask of bits which are writable in the guest's Config4 CP0
1012 * register, by userland (currently read-only to the guest).
1013 */
1014unsigned int kvm_mips_config4_wrmask(struct kvm_vcpu *vcpu)
1015{
1016 /* Config5 is optional */
1017 unsigned int mask = MIPS_CONF_M;
1018
1019 /* KScrExist */
1020 mask |= (unsigned int)vcpu->arch.kscratch_enabled << 16;
1021
1022 return mask;
1023}
1024
1025/**
1026 * kvm_mips_config5_wrmask() - Find mask of writable bits in guest Config5
1027 * @vcpu: Virtual CPU.
1028 *
1029 * Finds the mask of bits which are writable in the guest's Config5 CP0
1030 * register, by the guest itself.
1031 */
1032unsigned int kvm_mips_config5_wrmask(struct kvm_vcpu *vcpu)
1033{
1034 unsigned int mask = 0;
1035
1036 /* Permit MSAEn changes if MSA supported and enabled */
1037 if (kvm_mips_guest_has_msa(&vcpu->arch))
1038 mask |= MIPS_CONF5_MSAEN;
1039
1040 /*
1041 * Permit guest FPU mode changes if FPU is enabled and the relevant
1042 * feature exists according to FIR register.
1043 */
1044 if (kvm_mips_guest_has_fpu(&vcpu->arch)) {
1045 if (cpu_has_fre)
1046 mask |= MIPS_CONF5_FRE;
1047 /* We don't support UFR or UFE */
1048 }
1049
1050 return mask;
1051}
1052
1053enum emulation_result kvm_mips_emulate_CP0(union mips_instruction inst,
1054 u32 *opc, u32 cause,
1055 struct kvm_run *run,
1056 struct kvm_vcpu *vcpu)
1057{
1058 struct mips_coproc *cop0 = vcpu->arch.cop0;
1059 enum emulation_result er = EMULATE_DONE;
1060 u32 rt, rd, sel;
1061 unsigned long curr_pc;
1062 int cpu, i;
1063
1064 /*
1065 * Update PC and hold onto current PC in case there is
1066 * an error and we want to rollback the PC
1067 */
1068 curr_pc = vcpu->arch.pc;
1069 er = update_pc(vcpu, cause);
1070 if (er == EMULATE_FAIL)
1071 return er;
1072
1073 if (inst.co_format.co) {
1074 switch (inst.co_format.func) {
1075 case tlbr_op: /* Read indexed TLB entry */
1076 er = kvm_mips_emul_tlbr(vcpu);
1077 break;
1078 case tlbwi_op: /* Write indexed */
1079 er = kvm_mips_emul_tlbwi(vcpu);
1080 break;
1081 case tlbwr_op: /* Write random */
1082 er = kvm_mips_emul_tlbwr(vcpu);
1083 break;
1084 case tlbp_op: /* TLB Probe */
1085 er = kvm_mips_emul_tlbp(vcpu);
1086 break;
1087 case rfe_op:
1088 kvm_err("!!!COP0_RFE!!!\n");
1089 break;
1090 case eret_op:
1091 er = kvm_mips_emul_eret(vcpu);
1092 goto dont_update_pc;
1093 case wait_op:
1094 er = kvm_mips_emul_wait(vcpu);
1095 break;
1096 }
1097 } else {
1098 rt = inst.c0r_format.rt;
1099 rd = inst.c0r_format.rd;
1100 sel = inst.c0r_format.sel;
1101
1102 switch (inst.c0r_format.rs) {
1103 case mfc_op:
1104#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
1105 cop0->stat[rd][sel]++;
1106#endif
1107 /* Get reg */
1108 if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
1109 vcpu->arch.gprs[rt] =
1110 (s32)kvm_mips_read_count(vcpu);
1111 } else if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) {
1112 vcpu->arch.gprs[rt] = 0x0;
1113#ifdef CONFIG_KVM_MIPS_DYN_TRANS
1114 kvm_mips_trans_mfc0(inst, opc, vcpu);
1115#endif
1116 } else {
1117 vcpu->arch.gprs[rt] = (s32)cop0->reg[rd][sel];
1118
1119#ifdef CONFIG_KVM_MIPS_DYN_TRANS
1120 kvm_mips_trans_mfc0(inst, opc, vcpu);
1121#endif
1122 }
1123
1124 trace_kvm_hwr(vcpu, KVM_TRACE_MFC0,
1125 KVM_TRACE_COP0(rd, sel),
1126 vcpu->arch.gprs[rt]);
1127 break;
1128
1129 case dmfc_op:
1130 vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
1131
1132 trace_kvm_hwr(vcpu, KVM_TRACE_DMFC0,
1133 KVM_TRACE_COP0(rd, sel),
1134 vcpu->arch.gprs[rt]);
1135 break;
1136
1137 case mtc_op:
1138#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
1139 cop0->stat[rd][sel]++;
1140#endif
1141 trace_kvm_hwr(vcpu, KVM_TRACE_MTC0,
1142 KVM_TRACE_COP0(rd, sel),
1143 vcpu->arch.gprs[rt]);
1144
1145 if ((rd == MIPS_CP0_TLB_INDEX)
1146 && (vcpu->arch.gprs[rt] >=
1147 KVM_MIPS_GUEST_TLB_SIZE)) {
1148 kvm_err("Invalid TLB Index: %ld",
1149 vcpu->arch.gprs[rt]);
1150 er = EMULATE_FAIL;
1151 break;
1152 }
1153#define C0_EBASE_CORE_MASK 0xff
1154 if ((rd == MIPS_CP0_PRID) && (sel == 1)) {
1155 /* Preserve CORE number */
1156 kvm_change_c0_guest_ebase(cop0,
1157 ~(C0_EBASE_CORE_MASK),
1158 vcpu->arch.gprs[rt]);
1159 kvm_err("MTCz, cop0->reg[EBASE]: %#lx\n",
1160 kvm_read_c0_guest_ebase(cop0));
1161 } else if (rd == MIPS_CP0_TLB_HI && sel == 0) {
1162 u32 nasid =
1163 vcpu->arch.gprs[rt] & KVM_ENTRYHI_ASID;
1164 if (((kvm_read_c0_guest_entryhi(cop0) &
1165 KVM_ENTRYHI_ASID) != nasid)) {
1166 trace_kvm_asid_change(vcpu,
1167 kvm_read_c0_guest_entryhi(cop0)
1168 & KVM_ENTRYHI_ASID,
1169 nasid);
1170
1171 /*
1172 * Regenerate/invalidate kernel MMU
1173 * context.
1174 * The user MMU context will be
1175 * regenerated lazily on re-entry to
1176 * guest user if the guest ASID actually
1177 * changes.
1178 */
1179 preempt_disable();
1180 cpu = smp_processor_id();
1181 kvm_get_new_mmu_context(&vcpu->arch.guest_kernel_mm,
1182 cpu, vcpu);
1183 vcpu->arch.guest_kernel_asid[cpu] =
1184 vcpu->arch.guest_kernel_mm.context.asid[cpu];
1185 for_each_possible_cpu(i)
1186 if (i != cpu)
1187 vcpu->arch.guest_kernel_asid[i] = 0;
1188 preempt_enable();
1189 }
1190 kvm_write_c0_guest_entryhi(cop0,
1191 vcpu->arch.gprs[rt]);
1192 }
1193 /* Are we writing to COUNT */
1194 else if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
1195 kvm_mips_write_count(vcpu, vcpu->arch.gprs[rt]);
1196 goto done;
1197 } else if ((rd == MIPS_CP0_COMPARE) && (sel == 0)) {
1198 /* If we are writing to COMPARE */
1199 /* Clear pending timer interrupt, if any */
1200 kvm_mips_write_compare(vcpu,
1201 vcpu->arch.gprs[rt],
1202 true);
1203 } else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) {
1204 unsigned int old_val, val, change;
1205
1206 old_val = kvm_read_c0_guest_status(cop0);
1207 val = vcpu->arch.gprs[rt];
1208 change = val ^ old_val;
1209
1210 /* Make sure that the NMI bit is never set */
1211 val &= ~ST0_NMI;
1212
1213 /*
1214 * Don't allow CU1 or FR to be set unless FPU
1215 * capability enabled and exists in guest
1216 * configuration.
1217 */
1218 if (!kvm_mips_guest_has_fpu(&vcpu->arch))
1219 val &= ~(ST0_CU1 | ST0_FR);
1220
1221 /*
1222 * Also don't allow FR to be set if host doesn't
1223 * support it.
1224 */
1225 if (!(current_cpu_data.fpu_id & MIPS_FPIR_F64))
1226 val &= ~ST0_FR;
1227
1228
1229 /* Handle changes in FPU mode */
1230 preempt_disable();
1231
1232 /*
1233 * FPU and Vector register state is made
1234 * UNPREDICTABLE by a change of FR, so don't
1235 * even bother saving it.
1236 */
1237 if (change & ST0_FR)
1238 kvm_drop_fpu(vcpu);
1239
1240 /*
1241 * If MSA state is already live, it is undefined
1242 * how it interacts with FR=0 FPU state, and we
1243 * don't want to hit reserved instruction
1244 * exceptions trying to save the MSA state later
1245 * when CU=1 && FR=1, so play it safe and save
1246 * it first.
1247 */
1248 if (change & ST0_CU1 && !(val & ST0_FR) &&
1249 vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA)
1250 kvm_lose_fpu(vcpu);
1251
1252 /*
1253 * Propagate CU1 (FPU enable) changes
1254 * immediately if the FPU context is already
1255 * loaded. When disabling we leave the context
1256 * loaded so it can be quickly enabled again in
1257 * the near future.
1258 */
1259 if (change & ST0_CU1 &&
1260 vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU)
1261 change_c0_status(ST0_CU1, val);
1262
1263 preempt_enable();
1264
1265 kvm_write_c0_guest_status(cop0, val);
1266
1267#ifdef CONFIG_KVM_MIPS_DYN_TRANS
1268 /*
1269 * If FPU present, we need CU1/FR bits to take
1270 * effect fairly soon.
1271 */
1272 if (!kvm_mips_guest_has_fpu(&vcpu->arch))
1273 kvm_mips_trans_mtc0(inst, opc, vcpu);
1274#endif
1275 } else if ((rd == MIPS_CP0_CONFIG) && (sel == 5)) {
1276 unsigned int old_val, val, change, wrmask;
1277
1278 old_val = kvm_read_c0_guest_config5(cop0);
1279 val = vcpu->arch.gprs[rt];
1280
1281 /* Only a few bits are writable in Config5 */
1282 wrmask = kvm_mips_config5_wrmask(vcpu);
1283 change = (val ^ old_val) & wrmask;
1284 val = old_val ^ change;
1285
1286
1287 /* Handle changes in FPU/MSA modes */
1288 preempt_disable();
1289
1290 /*
1291 * Propagate FRE changes immediately if the FPU
1292 * context is already loaded.
1293 */
1294 if (change & MIPS_CONF5_FRE &&
1295 vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU)
1296 change_c0_config5(MIPS_CONF5_FRE, val);
1297
1298 /*
1299 * Propagate MSAEn changes immediately if the
1300 * MSA context is already loaded. When disabling
1301 * we leave the context loaded so it can be
1302 * quickly enabled again in the near future.
1303 */
1304 if (change & MIPS_CONF5_MSAEN &&
1305 vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA)
1306 change_c0_config5(MIPS_CONF5_MSAEN,
1307 val);
1308
1309 preempt_enable();
1310
1311 kvm_write_c0_guest_config5(cop0, val);
1312 } else if ((rd == MIPS_CP0_CAUSE) && (sel == 0)) {
1313 u32 old_cause, new_cause;
1314
1315 old_cause = kvm_read_c0_guest_cause(cop0);
1316 new_cause = vcpu->arch.gprs[rt];
1317 /* Update R/W bits */
1318 kvm_change_c0_guest_cause(cop0, 0x08800300,
1319 new_cause);
1320 /* DC bit enabling/disabling timer? */
1321 if ((old_cause ^ new_cause) & CAUSEF_DC) {
1322 if (new_cause & CAUSEF_DC)
1323 kvm_mips_count_disable_cause(vcpu);
1324 else
1325 kvm_mips_count_enable_cause(vcpu);
1326 }
1327 } else if ((rd == MIPS_CP0_HWRENA) && (sel == 0)) {
1328 u32 mask = MIPS_HWRENA_CPUNUM |
1329 MIPS_HWRENA_SYNCISTEP |
1330 MIPS_HWRENA_CC |
1331 MIPS_HWRENA_CCRES;
1332
1333 if (kvm_read_c0_guest_config3(cop0) &
1334 MIPS_CONF3_ULRI)
1335 mask |= MIPS_HWRENA_ULR;
1336 cop0->reg[rd][sel] = vcpu->arch.gprs[rt] & mask;
1337 } else {
1338 cop0->reg[rd][sel] = vcpu->arch.gprs[rt];
1339#ifdef CONFIG_KVM_MIPS_DYN_TRANS
1340 kvm_mips_trans_mtc0(inst, opc, vcpu);
1341#endif
1342 }
1343 break;
1344
1345 case dmtc_op:
1346 kvm_err("!!!!!!![%#lx]dmtc_op: rt: %d, rd: %d, sel: %d!!!!!!\n",
1347 vcpu->arch.pc, rt, rd, sel);
1348 trace_kvm_hwr(vcpu, KVM_TRACE_DMTC0,
1349 KVM_TRACE_COP0(rd, sel),
1350 vcpu->arch.gprs[rt]);
1351 er = EMULATE_FAIL;
1352 break;
1353
1354 case mfmc0_op:
1355#ifdef KVM_MIPS_DEBUG_COP0_COUNTERS
1356 cop0->stat[MIPS_CP0_STATUS][0]++;
1357#endif
1358 if (rt != 0)
1359 vcpu->arch.gprs[rt] =
1360 kvm_read_c0_guest_status(cop0);
1361 /* EI */
1362 if (inst.mfmc0_format.sc) {
1363 kvm_debug("[%#lx] mfmc0_op: EI\n",
1364 vcpu->arch.pc);
1365 kvm_set_c0_guest_status(cop0, ST0_IE);
1366 } else {
1367 kvm_debug("[%#lx] mfmc0_op: DI\n",
1368 vcpu->arch.pc);
1369 kvm_clear_c0_guest_status(cop0, ST0_IE);
1370 }
1371
1372 break;
1373
1374 case wrpgpr_op:
1375 {
1376 u32 css = cop0->reg[MIPS_CP0_STATUS][2] & 0xf;
1377 u32 pss =
1378 (cop0->reg[MIPS_CP0_STATUS][2] >> 6) & 0xf;
1379 /*
1380 * We don't support any shadow register sets, so
1381 * SRSCtl[PSS] == SRSCtl[CSS] = 0
1382 */
1383 if (css || pss) {
1384 er = EMULATE_FAIL;
1385 break;
1386 }
1387 kvm_debug("WRPGPR[%d][%d] = %#lx\n", pss, rd,
1388 vcpu->arch.gprs[rt]);
1389 vcpu->arch.gprs[rd] = vcpu->arch.gprs[rt];
1390 }
1391 break;
1392 default:
1393 kvm_err("[%#lx]MachEmulateCP0: unsupported COP0, copz: 0x%x\n",
1394 vcpu->arch.pc, inst.c0r_format.rs);
1395 er = EMULATE_FAIL;
1396 break;
1397 }
1398 }
1399
1400done:
1401 /* Rollback PC only if emulation was unsuccessful */
1402 if (er == EMULATE_FAIL)
1403 vcpu->arch.pc = curr_pc;
1404
1405dont_update_pc:
1406 /*
1407 * This is for special instructions whose emulation
1408 * updates the PC, so do not overwrite the PC under
1409 * any circumstances
1410 */
1411
1412 return er;
1413}
1414
1415enum emulation_result kvm_mips_emulate_store(union mips_instruction inst,
1416 u32 cause,
1417 struct kvm_run *run,
1418 struct kvm_vcpu *vcpu)
1419{
1420 enum emulation_result er = EMULATE_DO_MMIO;
1421 u32 rt;
1422 u32 bytes;
1423 void *data = run->mmio.data;
1424 unsigned long curr_pc;
1425
1426 /*
1427 * Update PC and hold onto current PC in case there is
1428 * an error and we want to rollback the PC
1429 */
1430 curr_pc = vcpu->arch.pc;
1431 er = update_pc(vcpu, cause);
1432 if (er == EMULATE_FAIL)
1433 return er;
1434
1435 rt = inst.i_format.rt;
1436
1437 switch (inst.i_format.opcode) {
1438 case sb_op:
1439 bytes = 1;
1440 if (bytes > sizeof(run->mmio.data)) {
1441 kvm_err("%s: bad MMIO length: %d\n", __func__,
1442 run->mmio.len);
1443 }
1444 run->mmio.phys_addr =
1445 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1446 host_cp0_badvaddr);
1447 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1448 er = EMULATE_FAIL;
1449 break;
1450 }
1451 run->mmio.len = bytes;
1452 run->mmio.is_write = 1;
1453 vcpu->mmio_needed = 1;
1454 vcpu->mmio_is_write = 1;
1455 *(u8 *) data = vcpu->arch.gprs[rt];
1456 kvm_debug("OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1457 vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt],
1458 *(u8 *) data);
1459
1460 break;
1461
1462 case sw_op:
1463 bytes = 4;
1464 if (bytes > sizeof(run->mmio.data)) {
1465 kvm_err("%s: bad MMIO length: %d\n", __func__,
1466 run->mmio.len);
1467 }
1468 run->mmio.phys_addr =
1469 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1470 host_cp0_badvaddr);
1471 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1472 er = EMULATE_FAIL;
1473 break;
1474 }
1475
1476 run->mmio.len = bytes;
1477 run->mmio.is_write = 1;
1478 vcpu->mmio_needed = 1;
1479 vcpu->mmio_is_write = 1;
1480 *(u32 *) data = vcpu->arch.gprs[rt];
1481
1482 kvm_debug("[%#lx] OP_SW: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1483 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1484 vcpu->arch.gprs[rt], *(u32 *) data);
1485 break;
1486
1487 case sh_op:
1488 bytes = 2;
1489 if (bytes > sizeof(run->mmio.data)) {
1490 kvm_err("%s: bad MMIO length: %d\n", __func__,
1491 run->mmio.len);
1492 }
1493 run->mmio.phys_addr =
1494 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1495 host_cp0_badvaddr);
1496 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1497 er = EMULATE_FAIL;
1498 break;
1499 }
1500
1501 run->mmio.len = bytes;
1502 run->mmio.is_write = 1;
1503 vcpu->mmio_needed = 1;
1504 vcpu->mmio_is_write = 1;
1505 *(u16 *) data = vcpu->arch.gprs[rt];
1506
1507 kvm_debug("[%#lx] OP_SH: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1508 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1509 vcpu->arch.gprs[rt], *(u32 *) data);
1510 break;
1511
1512 default:
1513 kvm_err("Store not yet supported (inst=0x%08x)\n",
1514 inst.word);
1515 er = EMULATE_FAIL;
1516 break;
1517 }
1518
1519 /* Rollback PC if emulation was unsuccessful */
1520 if (er == EMULATE_FAIL)
1521 vcpu->arch.pc = curr_pc;
1522
1523 return er;
1524}
1525
1526enum emulation_result kvm_mips_emulate_load(union mips_instruction inst,
1527 u32 cause, struct kvm_run *run,
1528 struct kvm_vcpu *vcpu)
1529{
1530 enum emulation_result er = EMULATE_DO_MMIO;
1531 unsigned long curr_pc;
1532 u32 op, rt;
1533 u32 bytes;
1534
1535 rt = inst.i_format.rt;
1536 op = inst.i_format.opcode;
1537
1538 /*
1539 * Find the resume PC now while we have safe and easy access to the
1540 * prior branch instruction, and save it for
1541 * kvm_mips_complete_mmio_load() to restore later.
1542 */
1543 curr_pc = vcpu->arch.pc;
1544 er = update_pc(vcpu, cause);
1545 if (er == EMULATE_FAIL)
1546 return er;
1547 vcpu->arch.io_pc = vcpu->arch.pc;
1548 vcpu->arch.pc = curr_pc;
1549
1550 vcpu->arch.io_gpr = rt;
1551
1552 switch (op) {
1553 case lw_op:
1554 bytes = 4;
1555 if (bytes > sizeof(run->mmio.data)) {
1556 kvm_err("%s: bad MMIO length: %d\n", __func__,
1557 run->mmio.len);
1558 er = EMULATE_FAIL;
1559 break;
1560 }
1561 run->mmio.phys_addr =
1562 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1563 host_cp0_badvaddr);
1564 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1565 er = EMULATE_FAIL;
1566 break;
1567 }
1568
1569 run->mmio.len = bytes;
1570 run->mmio.is_write = 0;
1571 vcpu->mmio_needed = 1;
1572 vcpu->mmio_is_write = 0;
1573 break;
1574
1575 case lh_op:
1576 case lhu_op:
1577 bytes = 2;
1578 if (bytes > sizeof(run->mmio.data)) {
1579 kvm_err("%s: bad MMIO length: %d\n", __func__,
1580 run->mmio.len);
1581 er = EMULATE_FAIL;
1582 break;
1583 }
1584 run->mmio.phys_addr =
1585 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1586 host_cp0_badvaddr);
1587 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1588 er = EMULATE_FAIL;
1589 break;
1590 }
1591
1592 run->mmio.len = bytes;
1593 run->mmio.is_write = 0;
1594 vcpu->mmio_needed = 1;
1595 vcpu->mmio_is_write = 0;
1596
1597 if (op == lh_op)
1598 vcpu->mmio_needed = 2;
1599 else
1600 vcpu->mmio_needed = 1;
1601
1602 break;
1603
1604 case lbu_op:
1605 case lb_op:
1606 bytes = 1;
1607 if (bytes > sizeof(run->mmio.data)) {
1608 kvm_err("%s: bad MMIO length: %d\n", __func__,
1609 run->mmio.len);
1610 er = EMULATE_FAIL;
1611 break;
1612 }
1613 run->mmio.phys_addr =
1614 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1615 host_cp0_badvaddr);
1616 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1617 er = EMULATE_FAIL;
1618 break;
1619 }
1620
1621 run->mmio.len = bytes;
1622 run->mmio.is_write = 0;
1623 vcpu->mmio_is_write = 0;
1624
1625 if (op == lb_op)
1626 vcpu->mmio_needed = 2;
1627 else
1628 vcpu->mmio_needed = 1;
1629
1630 break;
1631
1632 default:
1633 kvm_err("Load not yet supported (inst=0x%08x)\n",
1634 inst.word);
1635 er = EMULATE_FAIL;
1636 break;
1637 }
1638
1639 return er;
1640}
1641
1642enum emulation_result kvm_mips_emulate_cache(union mips_instruction inst,
1643 u32 *opc, u32 cause,
1644 struct kvm_run *run,
1645 struct kvm_vcpu *vcpu)
1646{
1647 struct mips_coproc *cop0 = vcpu->arch.cop0;
1648 enum emulation_result er = EMULATE_DONE;
1649 u32 cache, op_inst, op, base;
1650 s16 offset;
1651 struct kvm_vcpu_arch *arch = &vcpu->arch;
1652 unsigned long va;
1653 unsigned long curr_pc;
1654
1655 /*
1656 * Update PC and hold onto current PC in case there is
1657 * an error and we want to rollback the PC
1658 */
1659 curr_pc = vcpu->arch.pc;
1660 er = update_pc(vcpu, cause);
1661 if (er == EMULATE_FAIL)
1662 return er;
1663
1664 base = inst.i_format.rs;
1665 op_inst = inst.i_format.rt;
1666 if (cpu_has_mips_r6)
1667 offset = inst.spec3_format.simmediate;
1668 else
1669 offset = inst.i_format.simmediate;
1670 cache = op_inst & CacheOp_Cache;
1671 op = op_inst & CacheOp_Op;
1672
1673 va = arch->gprs[base] + offset;
1674
1675 kvm_debug("CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1676 cache, op, base, arch->gprs[base], offset);
1677
1678 /*
1679 * Treat INDEX_INV as a nop, basically issued by Linux on startup to
1680 * invalidate the caches entirely by stepping through all the
1681 * ways/indexes
1682 */
1683 if (op == Index_Writeback_Inv) {
1684 kvm_debug("@ %#lx/%#lx CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1685 vcpu->arch.pc, vcpu->arch.gprs[31], cache, op, base,
1686 arch->gprs[base], offset);
1687
1688 if (cache == Cache_D)
1689 r4k_blast_dcache();
1690 else if (cache == Cache_I)
1691 r4k_blast_icache();
1692 else {
1693 kvm_err("%s: unsupported CACHE INDEX operation\n",
1694 __func__);
1695 return EMULATE_FAIL;
1696 }
1697
1698#ifdef CONFIG_KVM_MIPS_DYN_TRANS
1699 kvm_mips_trans_cache_index(inst, opc, vcpu);
1700#endif
1701 goto done;
1702 }
1703
1704 preempt_disable();
1705 if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
1706 if (kvm_mips_host_tlb_lookup(vcpu, va) < 0 &&
1707 kvm_mips_handle_kseg0_tlb_fault(va, vcpu)) {
1708 kvm_err("%s: handling mapped kseg0 tlb fault for %lx, vcpu: %p, ASID: %#lx\n",
1709 __func__, va, vcpu, read_c0_entryhi());
1710 er = EMULATE_FAIL;
1711 preempt_enable();
1712 goto done;
1713 }
1714 } else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) ||
1715 KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
1716 int index;
1717
1718 /* If an entry already exists then skip */
1719 if (kvm_mips_host_tlb_lookup(vcpu, va) >= 0)
1720 goto skip_fault;
1721
1722 /*
1723 * If address not in the guest TLB, then give the guest a fault,
1724 * the resulting handler will do the right thing
1725 */
1726 index = kvm_mips_guest_tlb_lookup(vcpu, (va & VPN2_MASK) |
1727 (kvm_read_c0_guest_entryhi
1728 (cop0) & KVM_ENTRYHI_ASID));
1729
1730 if (index < 0) {
1731 vcpu->arch.host_cp0_badvaddr = va;
1732 vcpu->arch.pc = curr_pc;
1733 er = kvm_mips_emulate_tlbmiss_ld(cause, NULL, run,
1734 vcpu);
1735 preempt_enable();
1736 goto dont_update_pc;
1737 } else {
1738 struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
1739 /*
1740 * Check if the entry is valid, if not then setup a TLB
1741 * invalid exception to the guest
1742 */
1743 if (!TLB_IS_VALID(*tlb, va)) {
1744 vcpu->arch.host_cp0_badvaddr = va;
1745 vcpu->arch.pc = curr_pc;
1746 er = kvm_mips_emulate_tlbinv_ld(cause, NULL,
1747 run, vcpu);
1748 preempt_enable();
1749 goto dont_update_pc;
1750 }
1751 /*
1752 * We fault an entry from the guest tlb to the
1753 * shadow host TLB
1754 */
1755 if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb)) {
1756 kvm_err("%s: handling mapped seg tlb fault for %lx, index: %u, vcpu: %p, ASID: %#lx\n",
1757 __func__, va, index, vcpu,
1758 read_c0_entryhi());
1759 er = EMULATE_FAIL;
1760 preempt_enable();
1761 goto done;
1762 }
1763 }
1764 } else {
1765 kvm_err("INVALID CACHE INDEX/ADDRESS (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1766 cache, op, base, arch->gprs[base], offset);
1767 er = EMULATE_FAIL;
1768 preempt_enable();
1769 goto done;
1770
1771 }
1772
1773skip_fault:
1774 /* XXXKYMA: Only a subset of cache ops are supported, used by Linux */
1775 if (op_inst == Hit_Writeback_Inv_D || op_inst == Hit_Invalidate_D) {
1776 flush_dcache_line(va);
1777
1778#ifdef CONFIG_KVM_MIPS_DYN_TRANS
1779 /*
1780 * Replace the CACHE instruction, with a SYNCI, not the same,
1781 * but avoids a trap
1782 */
1783 kvm_mips_trans_cache_va(inst, opc, vcpu);
1784#endif
1785 } else if (op_inst == Hit_Invalidate_I) {
1786 flush_dcache_line(va);
1787 flush_icache_line(va);
1788
1789#ifdef CONFIG_KVM_MIPS_DYN_TRANS
1790 /* Replace the CACHE instruction, with a SYNCI */
1791 kvm_mips_trans_cache_va(inst, opc, vcpu);
1792#endif
1793 } else {
1794 kvm_err("NO-OP CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1795 cache, op, base, arch->gprs[base], offset);
1796 er = EMULATE_FAIL;
1797 }
1798
1799 preempt_enable();
1800done:
1801 /* Rollback PC only if emulation was unsuccessful */
1802 if (er == EMULATE_FAIL)
1803 vcpu->arch.pc = curr_pc;
1804
1805dont_update_pc:
1806 /*
1807 * This is for exceptions whose emulation updates the PC, so do not
1808 * overwrite the PC under any circumstances
1809 */
1810
1811 return er;
1812}
1813
1814enum emulation_result kvm_mips_emulate_inst(u32 cause, u32 *opc,
1815 struct kvm_run *run,
1816 struct kvm_vcpu *vcpu)
1817{
1818 union mips_instruction inst;
1819 enum emulation_result er = EMULATE_DONE;
1820
1821 /* Fetch the instruction. */
1822 if (cause & CAUSEF_BD)
1823 opc += 1;
1824
1825 inst.word = kvm_get_inst(opc, vcpu);
1826
1827 switch (inst.r_format.opcode) {
1828 case cop0_op:
1829 er = kvm_mips_emulate_CP0(inst, opc, cause, run, vcpu);
1830 break;
1831 case sb_op:
1832 case sh_op:
1833 case sw_op:
1834 er = kvm_mips_emulate_store(inst, cause, run, vcpu);
1835 break;
1836 case lb_op:
1837 case lbu_op:
1838 case lhu_op:
1839 case lh_op:
1840 case lw_op:
1841 er = kvm_mips_emulate_load(inst, cause, run, vcpu);
1842 break;
1843
1844#ifndef CONFIG_CPU_MIPSR6
1845 case cache_op:
1846 ++vcpu->stat.cache_exits;
1847 trace_kvm_exit(vcpu, KVM_TRACE_EXIT_CACHE);
1848 er = kvm_mips_emulate_cache(inst, opc, cause, run, vcpu);
1849 break;
1850#else
1851 case spec3_op:
1852 switch (inst.spec3_format.func) {
1853 case cache6_op:
1854 ++vcpu->stat.cache_exits;
1855 trace_kvm_exit(vcpu, KVM_TRACE_EXIT_CACHE);
1856 er = kvm_mips_emulate_cache(inst, opc, cause, run,
1857 vcpu);
1858 break;
1859 default:
1860 goto unknown;
1861 };
1862 break;
1863unknown:
1864#endif
1865
1866 default:
1867 kvm_err("Instruction emulation not supported (%p/%#x)\n", opc,
1868 inst.word);
1869 kvm_arch_vcpu_dump_regs(vcpu);
1870 er = EMULATE_FAIL;
1871 break;
1872 }
1873
1874 return er;
1875}
1876
1877enum emulation_result kvm_mips_emulate_syscall(u32 cause,
1878 u32 *opc,
1879 struct kvm_run *run,
1880 struct kvm_vcpu *vcpu)
1881{
1882 struct mips_coproc *cop0 = vcpu->arch.cop0;
1883 struct kvm_vcpu_arch *arch = &vcpu->arch;
1884 enum emulation_result er = EMULATE_DONE;
1885
1886 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1887 /* save old pc */
1888 kvm_write_c0_guest_epc(cop0, arch->pc);
1889 kvm_set_c0_guest_status(cop0, ST0_EXL);
1890
1891 if (cause & CAUSEF_BD)
1892 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1893 else
1894 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1895
1896 kvm_debug("Delivering SYSCALL @ pc %#lx\n", arch->pc);
1897
1898 kvm_change_c0_guest_cause(cop0, (0xff),
1899 (EXCCODE_SYS << CAUSEB_EXCCODE));
1900
1901 /* Set PC to the exception entry point */
1902 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1903
1904 } else {
1905 kvm_err("Trying to deliver SYSCALL when EXL is already set\n");
1906 er = EMULATE_FAIL;
1907 }
1908
1909 return er;
1910}
1911
1912enum emulation_result kvm_mips_emulate_tlbmiss_ld(u32 cause,
1913 u32 *opc,
1914 struct kvm_run *run,
1915 struct kvm_vcpu *vcpu)
1916{
1917 struct mips_coproc *cop0 = vcpu->arch.cop0;
1918 struct kvm_vcpu_arch *arch = &vcpu->arch;
1919 unsigned long entryhi = (vcpu->arch. host_cp0_badvaddr & VPN2_MASK) |
1920 (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
1921
1922 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1923 /* save old pc */
1924 kvm_write_c0_guest_epc(cop0, arch->pc);
1925 kvm_set_c0_guest_status(cop0, ST0_EXL);
1926
1927 if (cause & CAUSEF_BD)
1928 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1929 else
1930 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1931
1932 kvm_debug("[EXL == 0] delivering TLB MISS @ pc %#lx\n",
1933 arch->pc);
1934
1935 /* set pc to the exception entry point */
1936 arch->pc = KVM_GUEST_KSEG0 + 0x0;
1937
1938 } else {
1939 kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1940 arch->pc);
1941
1942 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1943 }
1944
1945 kvm_change_c0_guest_cause(cop0, (0xff),
1946 (EXCCODE_TLBL << CAUSEB_EXCCODE));
1947
1948 /* setup badvaddr, context and entryhi registers for the guest */
1949 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1950 /* XXXKYMA: is the context register used by linux??? */
1951 kvm_write_c0_guest_entryhi(cop0, entryhi);
1952 /* Blow away the shadow host TLBs */
1953 kvm_mips_flush_host_tlb(1);
1954
1955 return EMULATE_DONE;
1956}
1957
1958enum emulation_result kvm_mips_emulate_tlbinv_ld(u32 cause,
1959 u32 *opc,
1960 struct kvm_run *run,
1961 struct kvm_vcpu *vcpu)
1962{
1963 struct mips_coproc *cop0 = vcpu->arch.cop0;
1964 struct kvm_vcpu_arch *arch = &vcpu->arch;
1965 unsigned long entryhi =
1966 (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1967 (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
1968
1969 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1970 /* save old pc */
1971 kvm_write_c0_guest_epc(cop0, arch->pc);
1972 kvm_set_c0_guest_status(cop0, ST0_EXL);
1973
1974 if (cause & CAUSEF_BD)
1975 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1976 else
1977 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1978
1979 kvm_debug("[EXL == 0] delivering TLB INV @ pc %#lx\n",
1980 arch->pc);
1981
1982 /* set pc to the exception entry point */
1983 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1984
1985 } else {
1986 kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1987 arch->pc);
1988 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1989 }
1990
1991 kvm_change_c0_guest_cause(cop0, (0xff),
1992 (EXCCODE_TLBL << CAUSEB_EXCCODE));
1993
1994 /* setup badvaddr, context and entryhi registers for the guest */
1995 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1996 /* XXXKYMA: is the context register used by linux??? */
1997 kvm_write_c0_guest_entryhi(cop0, entryhi);
1998 /* Blow away the shadow host TLBs */
1999 kvm_mips_flush_host_tlb(1);
2000
2001 return EMULATE_DONE;
2002}
2003
2004enum emulation_result kvm_mips_emulate_tlbmiss_st(u32 cause,
2005 u32 *opc,
2006 struct kvm_run *run,
2007 struct kvm_vcpu *vcpu)
2008{
2009 struct mips_coproc *cop0 = vcpu->arch.cop0;
2010 struct kvm_vcpu_arch *arch = &vcpu->arch;
2011 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
2012 (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
2013
2014 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2015 /* save old pc */
2016 kvm_write_c0_guest_epc(cop0, arch->pc);
2017 kvm_set_c0_guest_status(cop0, ST0_EXL);
2018
2019 if (cause & CAUSEF_BD)
2020 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2021 else
2022 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2023
2024 kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
2025 arch->pc);
2026
2027 /* Set PC to the exception entry point */
2028 arch->pc = KVM_GUEST_KSEG0 + 0x0;
2029 } else {
2030 kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
2031 arch->pc);
2032 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2033 }
2034
2035 kvm_change_c0_guest_cause(cop0, (0xff),
2036 (EXCCODE_TLBS << CAUSEB_EXCCODE));
2037
2038 /* setup badvaddr, context and entryhi registers for the guest */
2039 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2040 /* XXXKYMA: is the context register used by linux??? */
2041 kvm_write_c0_guest_entryhi(cop0, entryhi);
2042 /* Blow away the shadow host TLBs */
2043 kvm_mips_flush_host_tlb(1);
2044
2045 return EMULATE_DONE;
2046}
2047
2048enum emulation_result kvm_mips_emulate_tlbinv_st(u32 cause,
2049 u32 *opc,
2050 struct kvm_run *run,
2051 struct kvm_vcpu *vcpu)
2052{
2053 struct mips_coproc *cop0 = vcpu->arch.cop0;
2054 struct kvm_vcpu_arch *arch = &vcpu->arch;
2055 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
2056 (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
2057
2058 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2059 /* save old pc */
2060 kvm_write_c0_guest_epc(cop0, arch->pc);
2061 kvm_set_c0_guest_status(cop0, ST0_EXL);
2062
2063 if (cause & CAUSEF_BD)
2064 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2065 else
2066 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2067
2068 kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
2069 arch->pc);
2070
2071 /* Set PC to the exception entry point */
2072 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2073 } else {
2074 kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
2075 arch->pc);
2076 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2077 }
2078
2079 kvm_change_c0_guest_cause(cop0, (0xff),
2080 (EXCCODE_TLBS << CAUSEB_EXCCODE));
2081
2082 /* setup badvaddr, context and entryhi registers for the guest */
2083 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2084 /* XXXKYMA: is the context register used by linux??? */
2085 kvm_write_c0_guest_entryhi(cop0, entryhi);
2086 /* Blow away the shadow host TLBs */
2087 kvm_mips_flush_host_tlb(1);
2088
2089 return EMULATE_DONE;
2090}
2091
2092/* TLBMOD: store into address matching TLB with Dirty bit off */
2093enum emulation_result kvm_mips_handle_tlbmod(u32 cause, u32 *opc,
2094 struct kvm_run *run,
2095 struct kvm_vcpu *vcpu)
2096{
2097 enum emulation_result er = EMULATE_DONE;
2098#ifdef DEBUG
2099 struct mips_coproc *cop0 = vcpu->arch.cop0;
2100 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
2101 (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
2102 int index;
2103
2104 /* If address not in the guest TLB, then we are in trouble */
2105 index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
2106 if (index < 0) {
2107 /* XXXKYMA Invalidate and retry */
2108 kvm_mips_host_tlb_inv(vcpu, vcpu->arch.host_cp0_badvaddr);
2109 kvm_err("%s: host got TLBMOD for %#lx but entry not present in Guest TLB\n",
2110 __func__, entryhi);
2111 kvm_mips_dump_guest_tlbs(vcpu);
2112 kvm_mips_dump_host_tlbs();
2113 return EMULATE_FAIL;
2114 }
2115#endif
2116
2117 er = kvm_mips_emulate_tlbmod(cause, opc, run, vcpu);
2118 return er;
2119}
2120
2121enum emulation_result kvm_mips_emulate_tlbmod(u32 cause,
2122 u32 *opc,
2123 struct kvm_run *run,
2124 struct kvm_vcpu *vcpu)
2125{
2126 struct mips_coproc *cop0 = vcpu->arch.cop0;
2127 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
2128 (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
2129 struct kvm_vcpu_arch *arch = &vcpu->arch;
2130
2131 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2132 /* save old pc */
2133 kvm_write_c0_guest_epc(cop0, arch->pc);
2134 kvm_set_c0_guest_status(cop0, ST0_EXL);
2135
2136 if (cause & CAUSEF_BD)
2137 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2138 else
2139 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2140
2141 kvm_debug("[EXL == 0] Delivering TLB MOD @ pc %#lx\n",
2142 arch->pc);
2143
2144 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2145 } else {
2146 kvm_debug("[EXL == 1] Delivering TLB MOD @ pc %#lx\n",
2147 arch->pc);
2148 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2149 }
2150
2151 kvm_change_c0_guest_cause(cop0, (0xff),
2152 (EXCCODE_MOD << CAUSEB_EXCCODE));
2153
2154 /* setup badvaddr, context and entryhi registers for the guest */
2155 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2156 /* XXXKYMA: is the context register used by linux??? */
2157 kvm_write_c0_guest_entryhi(cop0, entryhi);
2158 /* Blow away the shadow host TLBs */
2159 kvm_mips_flush_host_tlb(1);
2160
2161 return EMULATE_DONE;
2162}
2163
2164enum emulation_result kvm_mips_emulate_fpu_exc(u32 cause,
2165 u32 *opc,
2166 struct kvm_run *run,
2167 struct kvm_vcpu *vcpu)
2168{
2169 struct mips_coproc *cop0 = vcpu->arch.cop0;
2170 struct kvm_vcpu_arch *arch = &vcpu->arch;
2171
2172 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2173 /* save old pc */
2174 kvm_write_c0_guest_epc(cop0, arch->pc);
2175 kvm_set_c0_guest_status(cop0, ST0_EXL);
2176
2177 if (cause & CAUSEF_BD)
2178 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2179 else
2180 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2181
2182 }
2183
2184 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2185
2186 kvm_change_c0_guest_cause(cop0, (0xff),
2187 (EXCCODE_CPU << CAUSEB_EXCCODE));
2188 kvm_change_c0_guest_cause(cop0, (CAUSEF_CE), (0x1 << CAUSEB_CE));
2189
2190 return EMULATE_DONE;
2191}
2192
2193enum emulation_result kvm_mips_emulate_ri_exc(u32 cause,
2194 u32 *opc,
2195 struct kvm_run *run,
2196 struct kvm_vcpu *vcpu)
2197{
2198 struct mips_coproc *cop0 = vcpu->arch.cop0;
2199 struct kvm_vcpu_arch *arch = &vcpu->arch;
2200 enum emulation_result er = EMULATE_DONE;
2201
2202 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2203 /* save old pc */
2204 kvm_write_c0_guest_epc(cop0, arch->pc);
2205 kvm_set_c0_guest_status(cop0, ST0_EXL);
2206
2207 if (cause & CAUSEF_BD)
2208 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2209 else
2210 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2211
2212 kvm_debug("Delivering RI @ pc %#lx\n", arch->pc);
2213
2214 kvm_change_c0_guest_cause(cop0, (0xff),
2215 (EXCCODE_RI << CAUSEB_EXCCODE));
2216
2217 /* Set PC to the exception entry point */
2218 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2219
2220 } else {
2221 kvm_err("Trying to deliver RI when EXL is already set\n");
2222 er = EMULATE_FAIL;
2223 }
2224
2225 return er;
2226}
2227
2228enum emulation_result kvm_mips_emulate_bp_exc(u32 cause,
2229 u32 *opc,
2230 struct kvm_run *run,
2231 struct kvm_vcpu *vcpu)
2232{
2233 struct mips_coproc *cop0 = vcpu->arch.cop0;
2234 struct kvm_vcpu_arch *arch = &vcpu->arch;
2235 enum emulation_result er = EMULATE_DONE;
2236
2237 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2238 /* save old pc */
2239 kvm_write_c0_guest_epc(cop0, arch->pc);
2240 kvm_set_c0_guest_status(cop0, ST0_EXL);
2241
2242 if (cause & CAUSEF_BD)
2243 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2244 else
2245 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2246
2247 kvm_debug("Delivering BP @ pc %#lx\n", arch->pc);
2248
2249 kvm_change_c0_guest_cause(cop0, (0xff),
2250 (EXCCODE_BP << CAUSEB_EXCCODE));
2251
2252 /* Set PC to the exception entry point */
2253 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2254
2255 } else {
2256 kvm_err("Trying to deliver BP when EXL is already set\n");
2257 er = EMULATE_FAIL;
2258 }
2259
2260 return er;
2261}
2262
2263enum emulation_result kvm_mips_emulate_trap_exc(u32 cause,
2264 u32 *opc,
2265 struct kvm_run *run,
2266 struct kvm_vcpu *vcpu)
2267{
2268 struct mips_coproc *cop0 = vcpu->arch.cop0;
2269 struct kvm_vcpu_arch *arch = &vcpu->arch;
2270 enum emulation_result er = EMULATE_DONE;
2271
2272 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2273 /* save old pc */
2274 kvm_write_c0_guest_epc(cop0, arch->pc);
2275 kvm_set_c0_guest_status(cop0, ST0_EXL);
2276
2277 if (cause & CAUSEF_BD)
2278 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2279 else
2280 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2281
2282 kvm_debug("Delivering TRAP @ pc %#lx\n", arch->pc);
2283
2284 kvm_change_c0_guest_cause(cop0, (0xff),
2285 (EXCCODE_TR << CAUSEB_EXCCODE));
2286
2287 /* Set PC to the exception entry point */
2288 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2289
2290 } else {
2291 kvm_err("Trying to deliver TRAP when EXL is already set\n");
2292 er = EMULATE_FAIL;
2293 }
2294
2295 return er;
2296}
2297
2298enum emulation_result kvm_mips_emulate_msafpe_exc(u32 cause,
2299 u32 *opc,
2300 struct kvm_run *run,
2301 struct kvm_vcpu *vcpu)
2302{
2303 struct mips_coproc *cop0 = vcpu->arch.cop0;
2304 struct kvm_vcpu_arch *arch = &vcpu->arch;
2305 enum emulation_result er = EMULATE_DONE;
2306
2307 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2308 /* save old pc */
2309 kvm_write_c0_guest_epc(cop0, arch->pc);
2310 kvm_set_c0_guest_status(cop0, ST0_EXL);
2311
2312 if (cause & CAUSEF_BD)
2313 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2314 else
2315 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2316
2317 kvm_debug("Delivering MSAFPE @ pc %#lx\n", arch->pc);
2318
2319 kvm_change_c0_guest_cause(cop0, (0xff),
2320 (EXCCODE_MSAFPE << CAUSEB_EXCCODE));
2321
2322 /* Set PC to the exception entry point */
2323 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2324
2325 } else {
2326 kvm_err("Trying to deliver MSAFPE when EXL is already set\n");
2327 er = EMULATE_FAIL;
2328 }
2329
2330 return er;
2331}
2332
2333enum emulation_result kvm_mips_emulate_fpe_exc(u32 cause,
2334 u32 *opc,
2335 struct kvm_run *run,
2336 struct kvm_vcpu *vcpu)
2337{
2338 struct mips_coproc *cop0 = vcpu->arch.cop0;
2339 struct kvm_vcpu_arch *arch = &vcpu->arch;
2340 enum emulation_result er = EMULATE_DONE;
2341
2342 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2343 /* save old pc */
2344 kvm_write_c0_guest_epc(cop0, arch->pc);
2345 kvm_set_c0_guest_status(cop0, ST0_EXL);
2346
2347 if (cause & CAUSEF_BD)
2348 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2349 else
2350 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2351
2352 kvm_debug("Delivering FPE @ pc %#lx\n", arch->pc);
2353
2354 kvm_change_c0_guest_cause(cop0, (0xff),
2355 (EXCCODE_FPE << CAUSEB_EXCCODE));
2356
2357 /* Set PC to the exception entry point */
2358 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2359
2360 } else {
2361 kvm_err("Trying to deliver FPE when EXL is already set\n");
2362 er = EMULATE_FAIL;
2363 }
2364
2365 return er;
2366}
2367
2368enum emulation_result kvm_mips_emulate_msadis_exc(u32 cause,
2369 u32 *opc,
2370 struct kvm_run *run,
2371 struct kvm_vcpu *vcpu)
2372{
2373 struct mips_coproc *cop0 = vcpu->arch.cop0;
2374 struct kvm_vcpu_arch *arch = &vcpu->arch;
2375 enum emulation_result er = EMULATE_DONE;
2376
2377 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2378 /* save old pc */
2379 kvm_write_c0_guest_epc(cop0, arch->pc);
2380 kvm_set_c0_guest_status(cop0, ST0_EXL);
2381
2382 if (cause & CAUSEF_BD)
2383 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2384 else
2385 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2386
2387 kvm_debug("Delivering MSADIS @ pc %#lx\n", arch->pc);
2388
2389 kvm_change_c0_guest_cause(cop0, (0xff),
2390 (EXCCODE_MSADIS << CAUSEB_EXCCODE));
2391
2392 /* Set PC to the exception entry point */
2393 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2394
2395 } else {
2396 kvm_err("Trying to deliver MSADIS when EXL is already set\n");
2397 er = EMULATE_FAIL;
2398 }
2399
2400 return er;
2401}
2402
2403enum emulation_result kvm_mips_handle_ri(u32 cause, u32 *opc,
2404 struct kvm_run *run,
2405 struct kvm_vcpu *vcpu)
2406{
2407 struct mips_coproc *cop0 = vcpu->arch.cop0;
2408 struct kvm_vcpu_arch *arch = &vcpu->arch;
2409 enum emulation_result er = EMULATE_DONE;
2410 unsigned long curr_pc;
2411 union mips_instruction inst;
2412
2413 /*
2414 * Update PC and hold onto current PC in case there is
2415 * an error and we want to rollback the PC
2416 */
2417 curr_pc = vcpu->arch.pc;
2418 er = update_pc(vcpu, cause);
2419 if (er == EMULATE_FAIL)
2420 return er;
2421
2422 /* Fetch the instruction. */
2423 if (cause & CAUSEF_BD)
2424 opc += 1;
2425
2426 inst.word = kvm_get_inst(opc, vcpu);
2427
2428 if (inst.word == KVM_INVALID_INST) {
2429 kvm_err("%s: Cannot get inst @ %p\n", __func__, opc);
2430 return EMULATE_FAIL;
2431 }
2432
2433 if (inst.r_format.opcode == spec3_op &&
2434 inst.r_format.func == rdhwr_op &&
2435 inst.r_format.rs == 0 &&
2436 (inst.r_format.re >> 3) == 0) {
2437 int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
2438 int rd = inst.r_format.rd;
2439 int rt = inst.r_format.rt;
2440 int sel = inst.r_format.re & 0x7;
2441
2442 /* If usermode, check RDHWR rd is allowed by guest HWREna */
2443 if (usermode && !(kvm_read_c0_guest_hwrena(cop0) & BIT(rd))) {
2444 kvm_debug("RDHWR %#x disallowed by HWREna @ %p\n",
2445 rd, opc);
2446 goto emulate_ri;
2447 }
2448 switch (rd) {
2449 case MIPS_HWR_CPUNUM: /* CPU number */
2450 arch->gprs[rt] = vcpu->vcpu_id;
2451 break;
2452 case MIPS_HWR_SYNCISTEP: /* SYNCI length */
2453 arch->gprs[rt] = min(current_cpu_data.dcache.linesz,
2454 current_cpu_data.icache.linesz);
2455 break;
2456 case MIPS_HWR_CC: /* Read count register */
2457 arch->gprs[rt] = (s32)kvm_mips_read_count(vcpu);
2458 break;
2459 case MIPS_HWR_CCRES: /* Count register resolution */
2460 switch (current_cpu_data.cputype) {
2461 case CPU_20KC:
2462 case CPU_25KF:
2463 arch->gprs[rt] = 1;
2464 break;
2465 default:
2466 arch->gprs[rt] = 2;
2467 }
2468 break;
2469 case MIPS_HWR_ULR: /* Read UserLocal register */
2470 arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0);
2471 break;
2472
2473 default:
2474 kvm_debug("RDHWR %#x not supported @ %p\n", rd, opc);
2475 goto emulate_ri;
2476 }
2477
2478 trace_kvm_hwr(vcpu, KVM_TRACE_RDHWR, KVM_TRACE_HWR(rd, sel),
2479 vcpu->arch.gprs[rt]);
2480 } else {
2481 kvm_debug("Emulate RI not supported @ %p: %#x\n",
2482 opc, inst.word);
2483 goto emulate_ri;
2484 }
2485
2486 return EMULATE_DONE;
2487
2488emulate_ri:
2489 /*
2490 * Rollback PC (if in branch delay slot then the PC already points to
2491 * branch target), and pass the RI exception to the guest OS.
2492 */
2493 vcpu->arch.pc = curr_pc;
2494 return kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
2495}
2496
2497enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu,
2498 struct kvm_run *run)
2499{
2500 unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
2501 enum emulation_result er = EMULATE_DONE;
2502
2503 if (run->mmio.len > sizeof(*gpr)) {
2504 kvm_err("Bad MMIO length: %d", run->mmio.len);
2505 er = EMULATE_FAIL;
2506 goto done;
2507 }
2508
2509 /* Restore saved resume PC */
2510 vcpu->arch.pc = vcpu->arch.io_pc;
2511
2512 switch (run->mmio.len) {
2513 case 4:
2514 *gpr = *(s32 *) run->mmio.data;
2515 break;
2516
2517 case 2:
2518 if (vcpu->mmio_needed == 2)
2519 *gpr = *(s16 *) run->mmio.data;
2520 else
2521 *gpr = *(u16 *)run->mmio.data;
2522
2523 break;
2524 case 1:
2525 if (vcpu->mmio_needed == 2)
2526 *gpr = *(s8 *) run->mmio.data;
2527 else
2528 *gpr = *(u8 *) run->mmio.data;
2529 break;
2530 }
2531
2532done:
2533 return er;
2534}
2535
2536static enum emulation_result kvm_mips_emulate_exc(u32 cause,
2537 u32 *opc,
2538 struct kvm_run *run,
2539 struct kvm_vcpu *vcpu)
2540{
2541 u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2542 struct mips_coproc *cop0 = vcpu->arch.cop0;
2543 struct kvm_vcpu_arch *arch = &vcpu->arch;
2544 enum emulation_result er = EMULATE_DONE;
2545
2546 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2547 /* save old pc */
2548 kvm_write_c0_guest_epc(cop0, arch->pc);
2549 kvm_set_c0_guest_status(cop0, ST0_EXL);
2550
2551 if (cause & CAUSEF_BD)
2552 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2553 else
2554 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2555
2556 kvm_change_c0_guest_cause(cop0, (0xff),
2557 (exccode << CAUSEB_EXCCODE));
2558
2559 /* Set PC to the exception entry point */
2560 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2561 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2562
2563 kvm_debug("Delivering EXC %d @ pc %#lx, badVaddr: %#lx\n",
2564 exccode, kvm_read_c0_guest_epc(cop0),
2565 kvm_read_c0_guest_badvaddr(cop0));
2566 } else {
2567 kvm_err("Trying to deliver EXC when EXL is already set\n");
2568 er = EMULATE_FAIL;
2569 }
2570
2571 return er;
2572}
2573
2574enum emulation_result kvm_mips_check_privilege(u32 cause,
2575 u32 *opc,
2576 struct kvm_run *run,
2577 struct kvm_vcpu *vcpu)
2578{
2579 enum emulation_result er = EMULATE_DONE;
2580 u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2581 unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
2582
2583 int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
2584
2585 if (usermode) {
2586 switch (exccode) {
2587 case EXCCODE_INT:
2588 case EXCCODE_SYS:
2589 case EXCCODE_BP:
2590 case EXCCODE_RI:
2591 case EXCCODE_TR:
2592 case EXCCODE_MSAFPE:
2593 case EXCCODE_FPE:
2594 case EXCCODE_MSADIS:
2595 break;
2596
2597 case EXCCODE_CPU:
2598 if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 0)
2599 er = EMULATE_PRIV_FAIL;
2600 break;
2601
2602 case EXCCODE_MOD:
2603 break;
2604
2605 case EXCCODE_TLBL:
2606 /*
2607 * We we are accessing Guest kernel space, then send an
2608 * address error exception to the guest
2609 */
2610 if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
2611 kvm_debug("%s: LD MISS @ %#lx\n", __func__,
2612 badvaddr);
2613 cause &= ~0xff;
2614 cause |= (EXCCODE_ADEL << CAUSEB_EXCCODE);
2615 er = EMULATE_PRIV_FAIL;
2616 }
2617 break;
2618
2619 case EXCCODE_TLBS:
2620 /*
2621 * We we are accessing Guest kernel space, then send an
2622 * address error exception to the guest
2623 */
2624 if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
2625 kvm_debug("%s: ST MISS @ %#lx\n", __func__,
2626 badvaddr);
2627 cause &= ~0xff;
2628 cause |= (EXCCODE_ADES << CAUSEB_EXCCODE);
2629 er = EMULATE_PRIV_FAIL;
2630 }
2631 break;
2632
2633 case EXCCODE_ADES:
2634 kvm_debug("%s: address error ST @ %#lx\n", __func__,
2635 badvaddr);
2636 if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
2637 cause &= ~0xff;
2638 cause |= (EXCCODE_TLBS << CAUSEB_EXCCODE);
2639 }
2640 er = EMULATE_PRIV_FAIL;
2641 break;
2642 case EXCCODE_ADEL:
2643 kvm_debug("%s: address error LD @ %#lx\n", __func__,
2644 badvaddr);
2645 if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
2646 cause &= ~0xff;
2647 cause |= (EXCCODE_TLBL << CAUSEB_EXCCODE);
2648 }
2649 er = EMULATE_PRIV_FAIL;
2650 break;
2651 default:
2652 er = EMULATE_PRIV_FAIL;
2653 break;
2654 }
2655 }
2656
2657 if (er == EMULATE_PRIV_FAIL)
2658 kvm_mips_emulate_exc(cause, opc, run, vcpu);
2659
2660 return er;
2661}
2662
2663/*
2664 * User Address (UA) fault, this could happen if
2665 * (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this
2666 * case we pass on the fault to the guest kernel and let it handle it.
2667 * (2) TLB entry is present in the Guest TLB but not in the shadow, in this
2668 * case we inject the TLB from the Guest TLB into the shadow host TLB
2669 */
2670enum emulation_result kvm_mips_handle_tlbmiss(u32 cause,
2671 u32 *opc,
2672 struct kvm_run *run,
2673 struct kvm_vcpu *vcpu)
2674{
2675 enum emulation_result er = EMULATE_DONE;
2676 u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2677 unsigned long va = vcpu->arch.host_cp0_badvaddr;
2678 int index;
2679
2680 kvm_debug("kvm_mips_handle_tlbmiss: badvaddr: %#lx\n",
2681 vcpu->arch.host_cp0_badvaddr);
2682
2683 /*
2684 * KVM would not have got the exception if this entry was valid in the
2685 * shadow host TLB. Check the Guest TLB, if the entry is not there then
2686 * send the guest an exception. The guest exc handler should then inject
2687 * an entry into the guest TLB.
2688 */
2689 index = kvm_mips_guest_tlb_lookup(vcpu,
2690 (va & VPN2_MASK) |
2691 (kvm_read_c0_guest_entryhi(vcpu->arch.cop0) &
2692 KVM_ENTRYHI_ASID));
2693 if (index < 0) {
2694 if (exccode == EXCCODE_TLBL) {
2695 er = kvm_mips_emulate_tlbmiss_ld(cause, opc, run, vcpu);
2696 } else if (exccode == EXCCODE_TLBS) {
2697 er = kvm_mips_emulate_tlbmiss_st(cause, opc, run, vcpu);
2698 } else {
2699 kvm_err("%s: invalid exc code: %d\n", __func__,
2700 exccode);
2701 er = EMULATE_FAIL;
2702 }
2703 } else {
2704 struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
2705
2706 /*
2707 * Check if the entry is valid, if not then setup a TLB invalid
2708 * exception to the guest
2709 */
2710 if (!TLB_IS_VALID(*tlb, va)) {
2711 if (exccode == EXCCODE_TLBL) {
2712 er = kvm_mips_emulate_tlbinv_ld(cause, opc, run,
2713 vcpu);
2714 } else if (exccode == EXCCODE_TLBS) {
2715 er = kvm_mips_emulate_tlbinv_st(cause, opc, run,
2716 vcpu);
2717 } else {
2718 kvm_err("%s: invalid exc code: %d\n", __func__,
2719 exccode);
2720 er = EMULATE_FAIL;
2721 }
2722 } else {
2723 kvm_debug("Injecting hi: %#lx, lo0: %#lx, lo1: %#lx into shadow host TLB\n",
2724 tlb->tlb_hi, tlb->tlb_lo[0], tlb->tlb_lo[1]);
2725 /*
2726 * OK we have a Guest TLB entry, now inject it into the
2727 * shadow host TLB
2728 */
2729 if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb)) {
2730 kvm_err("%s: handling mapped seg tlb fault for %lx, index: %u, vcpu: %p, ASID: %#lx\n",
2731 __func__, va, index, vcpu,
2732 read_c0_entryhi());
2733 er = EMULATE_FAIL;
2734 }
2735 }
2736 }
2737
2738 return er;
2739}