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/memblock.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
34 #include "trace.h"
35
36 /*
37 * Compute the return address and do emulate branch simulation, if required.
38 * This function should be called only in branch delay slot active.
39 */
kvm_compute_return_epc(struct kvm_vcpu * vcpu,unsigned long instpc,unsigned long * out)40 static int kvm_compute_return_epc(struct kvm_vcpu *vcpu, unsigned long instpc,
41 unsigned long *out)
42 {
43 unsigned int dspcontrol;
44 union mips_instruction insn;
45 struct kvm_vcpu_arch *arch = &vcpu->arch;
46 long epc = instpc;
47 long nextpc;
48 int err;
49
50 if (epc & 3) {
51 kvm_err("%s: unaligned epc\n", __func__);
52 return -EINVAL;
53 }
54
55 /* Read the instruction */
56 err = kvm_get_badinstrp((u32 *)epc, vcpu, &insn.word);
57 if (err)
58 return err;
59
60 switch (insn.i_format.opcode) {
61 /* jr and jalr are in r_format format. */
62 case spec_op:
63 switch (insn.r_format.func) {
64 case jalr_op:
65 arch->gprs[insn.r_format.rd] = epc + 8;
66 fallthrough;
67 case jr_op:
68 nextpc = arch->gprs[insn.r_format.rs];
69 break;
70 default:
71 return -EINVAL;
72 }
73 break;
74
75 /*
76 * This group contains:
77 * bltz_op, bgez_op, bltzl_op, bgezl_op,
78 * bltzal_op, bgezal_op, bltzall_op, bgezall_op.
79 */
80 case bcond_op:
81 switch (insn.i_format.rt) {
82 case bltz_op:
83 case bltzl_op:
84 if ((long)arch->gprs[insn.i_format.rs] < 0)
85 epc = epc + 4 + (insn.i_format.simmediate << 2);
86 else
87 epc += 8;
88 nextpc = epc;
89 break;
90
91 case bgez_op:
92 case bgezl_op:
93 if ((long)arch->gprs[insn.i_format.rs] >= 0)
94 epc = epc + 4 + (insn.i_format.simmediate << 2);
95 else
96 epc += 8;
97 nextpc = epc;
98 break;
99
100 case bltzal_op:
101 case bltzall_op:
102 arch->gprs[31] = epc + 8;
103 if ((long)arch->gprs[insn.i_format.rs] < 0)
104 epc = epc + 4 + (insn.i_format.simmediate << 2);
105 else
106 epc += 8;
107 nextpc = epc;
108 break;
109
110 case bgezal_op:
111 case bgezall_op:
112 arch->gprs[31] = epc + 8;
113 if ((long)arch->gprs[insn.i_format.rs] >= 0)
114 epc = epc + 4 + (insn.i_format.simmediate << 2);
115 else
116 epc += 8;
117 nextpc = epc;
118 break;
119 case bposge32_op:
120 if (!cpu_has_dsp) {
121 kvm_err("%s: DSP branch but not DSP ASE\n",
122 __func__);
123 return -EINVAL;
124 }
125
126 dspcontrol = rddsp(0x01);
127
128 if (dspcontrol >= 32)
129 epc = epc + 4 + (insn.i_format.simmediate << 2);
130 else
131 epc += 8;
132 nextpc = epc;
133 break;
134 default:
135 return -EINVAL;
136 }
137 break;
138
139 /* These are unconditional and in j_format. */
140 case jal_op:
141 arch->gprs[31] = instpc + 8;
142 fallthrough;
143 case j_op:
144 epc += 4;
145 epc >>= 28;
146 epc <<= 28;
147 epc |= (insn.j_format.target << 2);
148 nextpc = epc;
149 break;
150
151 /* These are conditional and in i_format. */
152 case beq_op:
153 case beql_op:
154 if (arch->gprs[insn.i_format.rs] ==
155 arch->gprs[insn.i_format.rt])
156 epc = epc + 4 + (insn.i_format.simmediate << 2);
157 else
158 epc += 8;
159 nextpc = epc;
160 break;
161
162 case bne_op:
163 case bnel_op:
164 if (arch->gprs[insn.i_format.rs] !=
165 arch->gprs[insn.i_format.rt])
166 epc = epc + 4 + (insn.i_format.simmediate << 2);
167 else
168 epc += 8;
169 nextpc = epc;
170 break;
171
172 case blez_op: /* POP06 */
173 #ifndef CONFIG_CPU_MIPSR6
174 case blezl_op: /* removed in R6 */
175 #endif
176 if (insn.i_format.rt != 0)
177 goto compact_branch;
178 if ((long)arch->gprs[insn.i_format.rs] <= 0)
179 epc = epc + 4 + (insn.i_format.simmediate << 2);
180 else
181 epc += 8;
182 nextpc = epc;
183 break;
184
185 case bgtz_op: /* POP07 */
186 #ifndef CONFIG_CPU_MIPSR6
187 case bgtzl_op: /* removed in R6 */
188 #endif
189 if (insn.i_format.rt != 0)
190 goto compact_branch;
191 if ((long)arch->gprs[insn.i_format.rs] > 0)
192 epc = epc + 4 + (insn.i_format.simmediate << 2);
193 else
194 epc += 8;
195 nextpc = epc;
196 break;
197
198 /* And now the FPA/cp1 branch instructions. */
199 case cop1_op:
200 kvm_err("%s: unsupported cop1_op\n", __func__);
201 return -EINVAL;
202
203 #ifdef CONFIG_CPU_MIPSR6
204 /* R6 added the following compact branches with forbidden slots */
205 case blezl_op: /* POP26 */
206 case bgtzl_op: /* POP27 */
207 /* only rt == 0 isn't compact branch */
208 if (insn.i_format.rt != 0)
209 goto compact_branch;
210 return -EINVAL;
211 case pop10_op:
212 case pop30_op:
213 /* only rs == rt == 0 is reserved, rest are compact branches */
214 if (insn.i_format.rs != 0 || insn.i_format.rt != 0)
215 goto compact_branch;
216 return -EINVAL;
217 case pop66_op:
218 case pop76_op:
219 /* only rs == 0 isn't compact branch */
220 if (insn.i_format.rs != 0)
221 goto compact_branch;
222 return -EINVAL;
223 compact_branch:
224 /*
225 * If we've hit an exception on the forbidden slot, then
226 * the branch must not have been taken.
227 */
228 epc += 8;
229 nextpc = epc;
230 break;
231 #else
232 compact_branch:
233 /* Fall through - Compact branches not supported before R6 */
234 #endif
235 default:
236 return -EINVAL;
237 }
238
239 *out = nextpc;
240 return 0;
241 }
242
update_pc(struct kvm_vcpu * vcpu,u32 cause)243 enum emulation_result update_pc(struct kvm_vcpu *vcpu, u32 cause)
244 {
245 int err;
246
247 if (cause & CAUSEF_BD) {
248 err = kvm_compute_return_epc(vcpu, vcpu->arch.pc,
249 &vcpu->arch.pc);
250 if (err)
251 return EMULATE_FAIL;
252 } else {
253 vcpu->arch.pc += 4;
254 }
255
256 kvm_debug("update_pc(): New PC: %#lx\n", vcpu->arch.pc);
257
258 return EMULATE_DONE;
259 }
260
261 /**
262 * kvm_get_badinstr() - Get bad instruction encoding.
263 * @opc: Guest pointer to faulting instruction.
264 * @vcpu: KVM VCPU information.
265 *
266 * Gets the instruction encoding of the faulting instruction, using the saved
267 * BadInstr register value if it exists, otherwise falling back to reading guest
268 * memory at @opc.
269 *
270 * Returns: The instruction encoding of the faulting instruction.
271 */
kvm_get_badinstr(u32 * opc,struct kvm_vcpu * vcpu,u32 * out)272 int kvm_get_badinstr(u32 *opc, struct kvm_vcpu *vcpu, u32 *out)
273 {
274 if (cpu_has_badinstr) {
275 *out = vcpu->arch.host_cp0_badinstr;
276 return 0;
277 } else {
278 WARN_ONCE(1, "CPU doesn't have BadInstr register\n");
279 return -EINVAL;
280 }
281 }
282
283 /**
284 * kvm_get_badinstrp() - Get bad prior instruction encoding.
285 * @opc: Guest pointer to prior faulting instruction.
286 * @vcpu: KVM VCPU information.
287 *
288 * Gets the instruction encoding of the prior faulting instruction (the branch
289 * containing the delay slot which faulted), using the saved BadInstrP register
290 * value if it exists, otherwise falling back to reading guest memory at @opc.
291 *
292 * Returns: The instruction encoding of the prior faulting instruction.
293 */
kvm_get_badinstrp(u32 * opc,struct kvm_vcpu * vcpu,u32 * out)294 int kvm_get_badinstrp(u32 *opc, struct kvm_vcpu *vcpu, u32 *out)
295 {
296 if (cpu_has_badinstrp) {
297 *out = vcpu->arch.host_cp0_badinstrp;
298 return 0;
299 } else {
300 WARN_ONCE(1, "CPU doesn't have BadInstrp register\n");
301 return -EINVAL;
302 }
303 }
304
305 /**
306 * kvm_mips_count_disabled() - Find whether the CP0_Count timer is disabled.
307 * @vcpu: Virtual CPU.
308 *
309 * Returns: 1 if the CP0_Count timer is disabled by either the guest
310 * CP0_Cause.DC bit or the count_ctl.DC bit.
311 * 0 otherwise (in which case CP0_Count timer is running).
312 */
kvm_mips_count_disabled(struct kvm_vcpu * vcpu)313 int kvm_mips_count_disabled(struct kvm_vcpu *vcpu)
314 {
315 struct mips_coproc *cop0 = vcpu->arch.cop0;
316
317 return (vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) ||
318 (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC);
319 }
320
321 /**
322 * kvm_mips_ktime_to_count() - Scale ktime_t to a 32-bit count.
323 *
324 * Caches the dynamic nanosecond bias in vcpu->arch.count_dyn_bias.
325 *
326 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
327 */
kvm_mips_ktime_to_count(struct kvm_vcpu * vcpu,ktime_t now)328 static u32 kvm_mips_ktime_to_count(struct kvm_vcpu *vcpu, ktime_t now)
329 {
330 s64 now_ns, periods;
331 u64 delta;
332
333 now_ns = ktime_to_ns(now);
334 delta = now_ns + vcpu->arch.count_dyn_bias;
335
336 if (delta >= vcpu->arch.count_period) {
337 /* If delta is out of safe range the bias needs adjusting */
338 periods = div64_s64(now_ns, vcpu->arch.count_period);
339 vcpu->arch.count_dyn_bias = -periods * vcpu->arch.count_period;
340 /* Recalculate delta with new bias */
341 delta = now_ns + vcpu->arch.count_dyn_bias;
342 }
343
344 /*
345 * We've ensured that:
346 * delta < count_period
347 *
348 * Therefore the intermediate delta*count_hz will never overflow since
349 * at the boundary condition:
350 * delta = count_period
351 * delta = NSEC_PER_SEC * 2^32 / count_hz
352 * delta * count_hz = NSEC_PER_SEC * 2^32
353 */
354 return div_u64(delta * vcpu->arch.count_hz, NSEC_PER_SEC);
355 }
356
357 /**
358 * kvm_mips_count_time() - Get effective current time.
359 * @vcpu: Virtual CPU.
360 *
361 * Get effective monotonic ktime. This is usually a straightforward ktime_get(),
362 * except when the master disable bit is set in count_ctl, in which case it is
363 * count_resume, i.e. the time that the count was disabled.
364 *
365 * Returns: Effective monotonic ktime for CP0_Count.
366 */
kvm_mips_count_time(struct kvm_vcpu * vcpu)367 static inline ktime_t kvm_mips_count_time(struct kvm_vcpu *vcpu)
368 {
369 if (unlikely(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC))
370 return vcpu->arch.count_resume;
371
372 return ktime_get();
373 }
374
375 /**
376 * kvm_mips_read_count_running() - Read the current count value as if running.
377 * @vcpu: Virtual CPU.
378 * @now: Kernel time to read CP0_Count at.
379 *
380 * Returns the current guest CP0_Count register at time @now and handles if the
381 * timer interrupt is pending and hasn't been handled yet.
382 *
383 * Returns: The current value of the guest CP0_Count register.
384 */
kvm_mips_read_count_running(struct kvm_vcpu * vcpu,ktime_t now)385 static u32 kvm_mips_read_count_running(struct kvm_vcpu *vcpu, ktime_t now)
386 {
387 struct mips_coproc *cop0 = vcpu->arch.cop0;
388 ktime_t expires, threshold;
389 u32 count, compare;
390 int running;
391
392 /* Calculate the biased and scaled guest CP0_Count */
393 count = vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now);
394 compare = kvm_read_c0_guest_compare(cop0);
395
396 /*
397 * Find whether CP0_Count has reached the closest timer interrupt. If
398 * not, we shouldn't inject it.
399 */
400 if ((s32)(count - compare) < 0)
401 return count;
402
403 /*
404 * The CP0_Count we're going to return has already reached the closest
405 * timer interrupt. Quickly check if it really is a new interrupt by
406 * looking at whether the interval until the hrtimer expiry time is
407 * less than 1/4 of the timer period.
408 */
409 expires = hrtimer_get_expires(&vcpu->arch.comparecount_timer);
410 threshold = ktime_add_ns(now, vcpu->arch.count_period / 4);
411 if (ktime_before(expires, threshold)) {
412 /*
413 * Cancel it while we handle it so there's no chance of
414 * interference with the timeout handler.
415 */
416 running = hrtimer_cancel(&vcpu->arch.comparecount_timer);
417
418 /* Nothing should be waiting on the timeout */
419 kvm_mips_callbacks->queue_timer_int(vcpu);
420
421 /*
422 * Restart the timer if it was running based on the expiry time
423 * we read, so that we don't push it back 2 periods.
424 */
425 if (running) {
426 expires = ktime_add_ns(expires,
427 vcpu->arch.count_period);
428 hrtimer_start(&vcpu->arch.comparecount_timer, expires,
429 HRTIMER_MODE_ABS);
430 }
431 }
432
433 return count;
434 }
435
436 /**
437 * kvm_mips_read_count() - Read the current count value.
438 * @vcpu: Virtual CPU.
439 *
440 * Read the current guest CP0_Count value, taking into account whether the timer
441 * is stopped.
442 *
443 * Returns: The current guest CP0_Count value.
444 */
kvm_mips_read_count(struct kvm_vcpu * vcpu)445 u32 kvm_mips_read_count(struct kvm_vcpu *vcpu)
446 {
447 struct mips_coproc *cop0 = vcpu->arch.cop0;
448
449 /* If count disabled just read static copy of count */
450 if (kvm_mips_count_disabled(vcpu))
451 return kvm_read_c0_guest_count(cop0);
452
453 return kvm_mips_read_count_running(vcpu, ktime_get());
454 }
455
456 /**
457 * kvm_mips_freeze_hrtimer() - Safely stop the hrtimer.
458 * @vcpu: Virtual CPU.
459 * @count: Output pointer for CP0_Count value at point of freeze.
460 *
461 * Freeze the hrtimer safely and return both the ktime and the CP0_Count value
462 * at the point it was frozen. It is guaranteed that any pending interrupts at
463 * the point it was frozen are handled, and none after that point.
464 *
465 * This is useful where the time/CP0_Count is needed in the calculation of the
466 * new parameters.
467 *
468 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
469 *
470 * Returns: The ktime at the point of freeze.
471 */
kvm_mips_freeze_hrtimer(struct kvm_vcpu * vcpu,u32 * count)472 ktime_t kvm_mips_freeze_hrtimer(struct kvm_vcpu *vcpu, u32 *count)
473 {
474 ktime_t now;
475
476 /* stop hrtimer before finding time */
477 hrtimer_cancel(&vcpu->arch.comparecount_timer);
478 now = ktime_get();
479
480 /* find count at this point and handle pending hrtimer */
481 *count = kvm_mips_read_count_running(vcpu, now);
482
483 return now;
484 }
485
486 /**
487 * kvm_mips_resume_hrtimer() - Resume hrtimer, updating expiry.
488 * @vcpu: Virtual CPU.
489 * @now: ktime at point of resume.
490 * @count: CP0_Count at point of resume.
491 *
492 * Resumes the timer and updates the timer expiry based on @now and @count.
493 * This can be used in conjunction with kvm_mips_freeze_timer() when timer
494 * parameters need to be changed.
495 *
496 * It is guaranteed that a timer interrupt immediately after resume will be
497 * handled, but not if CP_Compare is exactly at @count. That case is already
498 * handled by kvm_mips_freeze_timer().
499 *
500 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
501 */
kvm_mips_resume_hrtimer(struct kvm_vcpu * vcpu,ktime_t now,u32 count)502 static void kvm_mips_resume_hrtimer(struct kvm_vcpu *vcpu,
503 ktime_t now, u32 count)
504 {
505 struct mips_coproc *cop0 = vcpu->arch.cop0;
506 u32 compare;
507 u64 delta;
508 ktime_t expire;
509
510 /* Calculate timeout (wrap 0 to 2^32) */
511 compare = kvm_read_c0_guest_compare(cop0);
512 delta = (u64)(u32)(compare - count - 1) + 1;
513 delta = div_u64(delta * NSEC_PER_SEC, vcpu->arch.count_hz);
514 expire = ktime_add_ns(now, delta);
515
516 /* Update hrtimer to use new timeout */
517 hrtimer_cancel(&vcpu->arch.comparecount_timer);
518 hrtimer_start(&vcpu->arch.comparecount_timer, expire, HRTIMER_MODE_ABS);
519 }
520
521 /**
522 * kvm_mips_restore_hrtimer() - Restore hrtimer after a gap, updating expiry.
523 * @vcpu: Virtual CPU.
524 * @before: Time before Count was saved, lower bound of drift calculation.
525 * @count: CP0_Count at point of restore.
526 * @min_drift: Minimum amount of drift permitted before correction.
527 * Must be <= 0.
528 *
529 * Restores the timer from a particular @count, accounting for drift. This can
530 * be used in conjunction with kvm_mips_freeze_timer() when a hardware timer is
531 * to be used for a period of time, but the exact ktime corresponding to the
532 * final Count that must be restored is not known.
533 *
534 * It is gauranteed that a timer interrupt immediately after restore will be
535 * handled, but not if CP0_Compare is exactly at @count. That case should
536 * already be handled when the hardware timer state is saved.
537 *
538 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is not
539 * stopped).
540 *
541 * Returns: Amount of correction to count_bias due to drift.
542 */
kvm_mips_restore_hrtimer(struct kvm_vcpu * vcpu,ktime_t before,u32 count,int min_drift)543 int kvm_mips_restore_hrtimer(struct kvm_vcpu *vcpu, ktime_t before,
544 u32 count, int min_drift)
545 {
546 ktime_t now, count_time;
547 u32 now_count, before_count;
548 u64 delta;
549 int drift, ret = 0;
550
551 /* Calculate expected count at before */
552 before_count = vcpu->arch.count_bias +
553 kvm_mips_ktime_to_count(vcpu, before);
554
555 /*
556 * Detect significantly negative drift, where count is lower than
557 * expected. Some negative drift is expected when hardware counter is
558 * set after kvm_mips_freeze_timer(), and it is harmless to allow the
559 * time to jump forwards a little, within reason. If the drift is too
560 * significant, adjust the bias to avoid a big Guest.CP0_Count jump.
561 */
562 drift = count - before_count;
563 if (drift < min_drift) {
564 count_time = before;
565 vcpu->arch.count_bias += drift;
566 ret = drift;
567 goto resume;
568 }
569
570 /* Calculate expected count right now */
571 now = ktime_get();
572 now_count = vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now);
573
574 /*
575 * Detect positive drift, where count is higher than expected, and
576 * adjust the bias to avoid guest time going backwards.
577 */
578 drift = count - now_count;
579 if (drift > 0) {
580 count_time = now;
581 vcpu->arch.count_bias += drift;
582 ret = drift;
583 goto resume;
584 }
585
586 /* Subtract nanosecond delta to find ktime when count was read */
587 delta = (u64)(u32)(now_count - count);
588 delta = div_u64(delta * NSEC_PER_SEC, vcpu->arch.count_hz);
589 count_time = ktime_sub_ns(now, delta);
590
591 resume:
592 /* Resume using the calculated ktime */
593 kvm_mips_resume_hrtimer(vcpu, count_time, count);
594 return ret;
595 }
596
597 /**
598 * kvm_mips_write_count() - Modify the count and update timer.
599 * @vcpu: Virtual CPU.
600 * @count: Guest CP0_Count value to set.
601 *
602 * Sets the CP0_Count value and updates the timer accordingly.
603 */
kvm_mips_write_count(struct kvm_vcpu * vcpu,u32 count)604 void kvm_mips_write_count(struct kvm_vcpu *vcpu, u32 count)
605 {
606 struct mips_coproc *cop0 = vcpu->arch.cop0;
607 ktime_t now;
608
609 /* Calculate bias */
610 now = kvm_mips_count_time(vcpu);
611 vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now);
612
613 if (kvm_mips_count_disabled(vcpu))
614 /* The timer's disabled, adjust the static count */
615 kvm_write_c0_guest_count(cop0, count);
616 else
617 /* Update timeout */
618 kvm_mips_resume_hrtimer(vcpu, now, count);
619 }
620
621 /**
622 * kvm_mips_init_count() - Initialise timer.
623 * @vcpu: Virtual CPU.
624 * @count_hz: Frequency of timer.
625 *
626 * Initialise the timer to the specified frequency, zero it, and set it going if
627 * it's enabled.
628 */
kvm_mips_init_count(struct kvm_vcpu * vcpu,unsigned long count_hz)629 void kvm_mips_init_count(struct kvm_vcpu *vcpu, unsigned long count_hz)
630 {
631 vcpu->arch.count_hz = count_hz;
632 vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32, count_hz);
633 vcpu->arch.count_dyn_bias = 0;
634
635 /* Starting at 0 */
636 kvm_mips_write_count(vcpu, 0);
637 }
638
639 /**
640 * kvm_mips_set_count_hz() - Update the frequency of the timer.
641 * @vcpu: Virtual CPU.
642 * @count_hz: Frequency of CP0_Count timer in Hz.
643 *
644 * Change the frequency of the CP0_Count timer. This is done atomically so that
645 * CP0_Count is continuous and no timer interrupt is lost.
646 *
647 * Returns: -EINVAL if @count_hz is out of range.
648 * 0 on success.
649 */
kvm_mips_set_count_hz(struct kvm_vcpu * vcpu,s64 count_hz)650 int kvm_mips_set_count_hz(struct kvm_vcpu *vcpu, s64 count_hz)
651 {
652 struct mips_coproc *cop0 = vcpu->arch.cop0;
653 int dc;
654 ktime_t now;
655 u32 count;
656
657 /* ensure the frequency is in a sensible range... */
658 if (count_hz <= 0 || count_hz > NSEC_PER_SEC)
659 return -EINVAL;
660 /* ... and has actually changed */
661 if (vcpu->arch.count_hz == count_hz)
662 return 0;
663
664 /* Safely freeze timer so we can keep it continuous */
665 dc = kvm_mips_count_disabled(vcpu);
666 if (dc) {
667 now = kvm_mips_count_time(vcpu);
668 count = kvm_read_c0_guest_count(cop0);
669 } else {
670 now = kvm_mips_freeze_hrtimer(vcpu, &count);
671 }
672
673 /* Update the frequency */
674 vcpu->arch.count_hz = count_hz;
675 vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32, count_hz);
676 vcpu->arch.count_dyn_bias = 0;
677
678 /* Calculate adjusted bias so dynamic count is unchanged */
679 vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now);
680
681 /* Update and resume hrtimer */
682 if (!dc)
683 kvm_mips_resume_hrtimer(vcpu, now, count);
684 return 0;
685 }
686
687 /**
688 * kvm_mips_write_compare() - Modify compare and update timer.
689 * @vcpu: Virtual CPU.
690 * @compare: New CP0_Compare value.
691 * @ack: Whether to acknowledge timer interrupt.
692 *
693 * Update CP0_Compare to a new value and update the timeout.
694 * If @ack, atomically acknowledge any pending timer interrupt, otherwise ensure
695 * any pending timer interrupt is preserved.
696 */
kvm_mips_write_compare(struct kvm_vcpu * vcpu,u32 compare,bool ack)697 void kvm_mips_write_compare(struct kvm_vcpu *vcpu, u32 compare, bool ack)
698 {
699 struct mips_coproc *cop0 = vcpu->arch.cop0;
700 int dc;
701 u32 old_compare = kvm_read_c0_guest_compare(cop0);
702 s32 delta = compare - old_compare;
703 u32 cause;
704 ktime_t now = ktime_set(0, 0); /* silence bogus GCC warning */
705 u32 count;
706
707 /* if unchanged, must just be an ack */
708 if (old_compare == compare) {
709 if (!ack)
710 return;
711 kvm_mips_callbacks->dequeue_timer_int(vcpu);
712 kvm_write_c0_guest_compare(cop0, compare);
713 return;
714 }
715
716 /*
717 * If guest CP0_Compare moves forward, CP0_GTOffset should be adjusted
718 * too to prevent guest CP0_Count hitting guest CP0_Compare.
719 *
720 * The new GTOffset corresponds to the new value of CP0_Compare, and is
721 * set prior to it being written into the guest context. We disable
722 * preemption until the new value is written to prevent restore of a
723 * GTOffset corresponding to the old CP0_Compare value.
724 */
725 if (delta > 0) {
726 preempt_disable();
727 write_c0_gtoffset(compare - read_c0_count());
728 back_to_back_c0_hazard();
729 }
730
731 /* freeze_hrtimer() takes care of timer interrupts <= count */
732 dc = kvm_mips_count_disabled(vcpu);
733 if (!dc)
734 now = kvm_mips_freeze_hrtimer(vcpu, &count);
735
736 if (ack)
737 kvm_mips_callbacks->dequeue_timer_int(vcpu);
738 else
739 /*
740 * With VZ, writing CP0_Compare acks (clears) CP0_Cause.TI, so
741 * preserve guest CP0_Cause.TI if we don't want to ack it.
742 */
743 cause = kvm_read_c0_guest_cause(cop0);
744
745 kvm_write_c0_guest_compare(cop0, compare);
746
747 if (delta > 0)
748 preempt_enable();
749
750 back_to_back_c0_hazard();
751
752 if (!ack && cause & CAUSEF_TI)
753 kvm_write_c0_guest_cause(cop0, cause);
754
755 /* resume_hrtimer() takes care of timer interrupts > count */
756 if (!dc)
757 kvm_mips_resume_hrtimer(vcpu, now, count);
758
759 /*
760 * If guest CP0_Compare is moving backward, we delay CP0_GTOffset change
761 * until after the new CP0_Compare is written, otherwise new guest
762 * CP0_Count could hit new guest CP0_Compare.
763 */
764 if (delta <= 0)
765 write_c0_gtoffset(compare - read_c0_count());
766 }
767
768 /**
769 * kvm_mips_count_disable() - Disable count.
770 * @vcpu: Virtual CPU.
771 *
772 * Disable the CP0_Count timer. A timer interrupt on or before the final stop
773 * time will be handled but not after.
774 *
775 * Assumes CP0_Count was previously enabled but now Guest.CP0_Cause.DC or
776 * count_ctl.DC has been set (count disabled).
777 *
778 * Returns: The time that the timer was stopped.
779 */
kvm_mips_count_disable(struct kvm_vcpu * vcpu)780 static ktime_t kvm_mips_count_disable(struct kvm_vcpu *vcpu)
781 {
782 struct mips_coproc *cop0 = vcpu->arch.cop0;
783 u32 count;
784 ktime_t now;
785
786 /* Stop hrtimer */
787 hrtimer_cancel(&vcpu->arch.comparecount_timer);
788
789 /* Set the static count from the dynamic count, handling pending TI */
790 now = ktime_get();
791 count = kvm_mips_read_count_running(vcpu, now);
792 kvm_write_c0_guest_count(cop0, count);
793
794 return now;
795 }
796
797 /**
798 * kvm_mips_count_disable_cause() - Disable count using CP0_Cause.DC.
799 * @vcpu: Virtual CPU.
800 *
801 * Disable the CP0_Count timer and set CP0_Cause.DC. A timer interrupt on or
802 * before the final stop time will be handled if the timer isn't disabled by
803 * count_ctl.DC, but not after.
804 *
805 * Assumes CP0_Cause.DC is clear (count enabled).
806 */
kvm_mips_count_disable_cause(struct kvm_vcpu * vcpu)807 void kvm_mips_count_disable_cause(struct kvm_vcpu *vcpu)
808 {
809 struct mips_coproc *cop0 = vcpu->arch.cop0;
810
811 kvm_set_c0_guest_cause(cop0, CAUSEF_DC);
812 if (!(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC))
813 kvm_mips_count_disable(vcpu);
814 }
815
816 /**
817 * kvm_mips_count_enable_cause() - Enable count using CP0_Cause.DC.
818 * @vcpu: Virtual CPU.
819 *
820 * Enable the CP0_Count timer and clear CP0_Cause.DC. A timer interrupt after
821 * the start time will be handled if the timer isn't disabled by count_ctl.DC,
822 * potentially before even returning, so the caller should be careful with
823 * ordering of CP0_Cause modifications so as not to lose it.
824 *
825 * Assumes CP0_Cause.DC is set (count disabled).
826 */
kvm_mips_count_enable_cause(struct kvm_vcpu * vcpu)827 void kvm_mips_count_enable_cause(struct kvm_vcpu *vcpu)
828 {
829 struct mips_coproc *cop0 = vcpu->arch.cop0;
830 u32 count;
831
832 kvm_clear_c0_guest_cause(cop0, CAUSEF_DC);
833
834 /*
835 * Set the dynamic count to match the static count.
836 * This starts the hrtimer if count_ctl.DC allows it.
837 * Otherwise it conveniently updates the biases.
838 */
839 count = kvm_read_c0_guest_count(cop0);
840 kvm_mips_write_count(vcpu, count);
841 }
842
843 /**
844 * kvm_mips_set_count_ctl() - Update the count control KVM register.
845 * @vcpu: Virtual CPU.
846 * @count_ctl: Count control register new value.
847 *
848 * Set the count control KVM register. The timer is updated accordingly.
849 *
850 * Returns: -EINVAL if reserved bits are set.
851 * 0 on success.
852 */
kvm_mips_set_count_ctl(struct kvm_vcpu * vcpu,s64 count_ctl)853 int kvm_mips_set_count_ctl(struct kvm_vcpu *vcpu, s64 count_ctl)
854 {
855 struct mips_coproc *cop0 = vcpu->arch.cop0;
856 s64 changed = count_ctl ^ vcpu->arch.count_ctl;
857 s64 delta;
858 ktime_t expire, now;
859 u32 count, compare;
860
861 /* Only allow defined bits to be changed */
862 if (changed & ~(s64)(KVM_REG_MIPS_COUNT_CTL_DC))
863 return -EINVAL;
864
865 /* Apply new value */
866 vcpu->arch.count_ctl = count_ctl;
867
868 /* Master CP0_Count disable */
869 if (changed & KVM_REG_MIPS_COUNT_CTL_DC) {
870 /* Is CP0_Cause.DC already disabling CP0_Count? */
871 if (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC) {
872 if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC)
873 /* Just record the current time */
874 vcpu->arch.count_resume = ktime_get();
875 } else if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) {
876 /* disable timer and record current time */
877 vcpu->arch.count_resume = kvm_mips_count_disable(vcpu);
878 } else {
879 /*
880 * Calculate timeout relative to static count at resume
881 * time (wrap 0 to 2^32).
882 */
883 count = kvm_read_c0_guest_count(cop0);
884 compare = kvm_read_c0_guest_compare(cop0);
885 delta = (u64)(u32)(compare - count - 1) + 1;
886 delta = div_u64(delta * NSEC_PER_SEC,
887 vcpu->arch.count_hz);
888 expire = ktime_add_ns(vcpu->arch.count_resume, delta);
889
890 /* Handle pending interrupt */
891 now = ktime_get();
892 if (ktime_compare(now, expire) >= 0)
893 /* Nothing should be waiting on the timeout */
894 kvm_mips_callbacks->queue_timer_int(vcpu);
895
896 /* Resume hrtimer without changing bias */
897 count = kvm_mips_read_count_running(vcpu, now);
898 kvm_mips_resume_hrtimer(vcpu, now, count);
899 }
900 }
901
902 return 0;
903 }
904
905 /**
906 * kvm_mips_set_count_resume() - Update the count resume KVM register.
907 * @vcpu: Virtual CPU.
908 * @count_resume: Count resume register new value.
909 *
910 * Set the count resume KVM register.
911 *
912 * Returns: -EINVAL if out of valid range (0..now).
913 * 0 on success.
914 */
kvm_mips_set_count_resume(struct kvm_vcpu * vcpu,s64 count_resume)915 int kvm_mips_set_count_resume(struct kvm_vcpu *vcpu, s64 count_resume)
916 {
917 /*
918 * It doesn't make sense for the resume time to be in the future, as it
919 * would be possible for the next interrupt to be more than a full
920 * period in the future.
921 */
922 if (count_resume < 0 || count_resume > ktime_to_ns(ktime_get()))
923 return -EINVAL;
924
925 vcpu->arch.count_resume = ns_to_ktime(count_resume);
926 return 0;
927 }
928
929 /**
930 * kvm_mips_count_timeout() - Push timer forward on timeout.
931 * @vcpu: Virtual CPU.
932 *
933 * Handle an hrtimer event by push the hrtimer forward a period.
934 *
935 * Returns: The hrtimer_restart value to return to the hrtimer subsystem.
936 */
kvm_mips_count_timeout(struct kvm_vcpu * vcpu)937 enum hrtimer_restart kvm_mips_count_timeout(struct kvm_vcpu *vcpu)
938 {
939 /* Add the Count period to the current expiry time */
940 hrtimer_add_expires_ns(&vcpu->arch.comparecount_timer,
941 vcpu->arch.count_period);
942 return HRTIMER_RESTART;
943 }
944
kvm_mips_emul_wait(struct kvm_vcpu * vcpu)945 enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
946 {
947 kvm_debug("[%#lx] !!!WAIT!!! (%#lx)\n", vcpu->arch.pc,
948 vcpu->arch.pending_exceptions);
949
950 ++vcpu->stat.wait_exits;
951 trace_kvm_exit(vcpu, KVM_TRACE_EXIT_WAIT);
952 if (!vcpu->arch.pending_exceptions) {
953 kvm_vz_lose_htimer(vcpu);
954 vcpu->arch.wait = 1;
955 kvm_vcpu_halt(vcpu);
956
957 /*
958 * We are runnable, then definitely go off to user space to
959 * check if any I/O interrupts are pending.
960 */
961 if (kvm_arch_vcpu_runnable(vcpu))
962 vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
963 }
964
965 return EMULATE_DONE;
966 }
967
kvm_mips_emulate_store(union mips_instruction inst,u32 cause,struct kvm_vcpu * vcpu)968 enum emulation_result kvm_mips_emulate_store(union mips_instruction inst,
969 u32 cause,
970 struct kvm_vcpu *vcpu)
971 {
972 int r;
973 enum emulation_result er;
974 u32 rt;
975 struct kvm_run *run = vcpu->run;
976 void *data = run->mmio.data;
977 unsigned int imme;
978 unsigned long curr_pc;
979
980 /*
981 * Update PC and hold onto current PC in case there is
982 * an error and we want to rollback the PC
983 */
984 curr_pc = vcpu->arch.pc;
985 er = update_pc(vcpu, cause);
986 if (er == EMULATE_FAIL)
987 return er;
988
989 rt = inst.i_format.rt;
990
991 run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
992 vcpu->arch.host_cp0_badvaddr);
993 if (run->mmio.phys_addr == KVM_INVALID_ADDR)
994 goto out_fail;
995
996 switch (inst.i_format.opcode) {
997 #if defined(CONFIG_64BIT)
998 case sd_op:
999 run->mmio.len = 8;
1000 *(u64 *)data = vcpu->arch.gprs[rt];
1001
1002 kvm_debug("[%#lx] OP_SD: eaddr: %#lx, gpr: %#lx, data: %#llx\n",
1003 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1004 vcpu->arch.gprs[rt], *(u64 *)data);
1005 break;
1006 #endif
1007
1008 case sw_op:
1009 run->mmio.len = 4;
1010 *(u32 *)data = vcpu->arch.gprs[rt];
1011
1012 kvm_debug("[%#lx] OP_SW: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1013 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1014 vcpu->arch.gprs[rt], *(u32 *)data);
1015 break;
1016
1017 case sh_op:
1018 run->mmio.len = 2;
1019 *(u16 *)data = vcpu->arch.gprs[rt];
1020
1021 kvm_debug("[%#lx] OP_SH: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1022 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1023 vcpu->arch.gprs[rt], *(u16 *)data);
1024 break;
1025
1026 case sb_op:
1027 run->mmio.len = 1;
1028 *(u8 *)data = vcpu->arch.gprs[rt];
1029
1030 kvm_debug("[%#lx] OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1031 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1032 vcpu->arch.gprs[rt], *(u8 *)data);
1033 break;
1034
1035 case swl_op:
1036 run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
1037 vcpu->arch.host_cp0_badvaddr) & (~0x3);
1038 run->mmio.len = 4;
1039 imme = vcpu->arch.host_cp0_badvaddr & 0x3;
1040 switch (imme) {
1041 case 0:
1042 *(u32 *)data = ((*(u32 *)data) & 0xffffff00) |
1043 (vcpu->arch.gprs[rt] >> 24);
1044 break;
1045 case 1:
1046 *(u32 *)data = ((*(u32 *)data) & 0xffff0000) |
1047 (vcpu->arch.gprs[rt] >> 16);
1048 break;
1049 case 2:
1050 *(u32 *)data = ((*(u32 *)data) & 0xff000000) |
1051 (vcpu->arch.gprs[rt] >> 8);
1052 break;
1053 case 3:
1054 *(u32 *)data = vcpu->arch.gprs[rt];
1055 break;
1056 default:
1057 break;
1058 }
1059
1060 kvm_debug("[%#lx] OP_SWL: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1061 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1062 vcpu->arch.gprs[rt], *(u32 *)data);
1063 break;
1064
1065 case swr_op:
1066 run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
1067 vcpu->arch.host_cp0_badvaddr) & (~0x3);
1068 run->mmio.len = 4;
1069 imme = vcpu->arch.host_cp0_badvaddr & 0x3;
1070 switch (imme) {
1071 case 0:
1072 *(u32 *)data = vcpu->arch.gprs[rt];
1073 break;
1074 case 1:
1075 *(u32 *)data = ((*(u32 *)data) & 0xff) |
1076 (vcpu->arch.gprs[rt] << 8);
1077 break;
1078 case 2:
1079 *(u32 *)data = ((*(u32 *)data) & 0xffff) |
1080 (vcpu->arch.gprs[rt] << 16);
1081 break;
1082 case 3:
1083 *(u32 *)data = ((*(u32 *)data) & 0xffffff) |
1084 (vcpu->arch.gprs[rt] << 24);
1085 break;
1086 default:
1087 break;
1088 }
1089
1090 kvm_debug("[%#lx] OP_SWR: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1091 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1092 vcpu->arch.gprs[rt], *(u32 *)data);
1093 break;
1094
1095 #if defined(CONFIG_64BIT)
1096 case sdl_op:
1097 run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
1098 vcpu->arch.host_cp0_badvaddr) & (~0x7);
1099
1100 run->mmio.len = 8;
1101 imme = vcpu->arch.host_cp0_badvaddr & 0x7;
1102 switch (imme) {
1103 case 0:
1104 *(u64 *)data = ((*(u64 *)data) & 0xffffffffffffff00) |
1105 ((vcpu->arch.gprs[rt] >> 56) & 0xff);
1106 break;
1107 case 1:
1108 *(u64 *)data = ((*(u64 *)data) & 0xffffffffffff0000) |
1109 ((vcpu->arch.gprs[rt] >> 48) & 0xffff);
1110 break;
1111 case 2:
1112 *(u64 *)data = ((*(u64 *)data) & 0xffffffffff000000) |
1113 ((vcpu->arch.gprs[rt] >> 40) & 0xffffff);
1114 break;
1115 case 3:
1116 *(u64 *)data = ((*(u64 *)data) & 0xffffffff00000000) |
1117 ((vcpu->arch.gprs[rt] >> 32) & 0xffffffff);
1118 break;
1119 case 4:
1120 *(u64 *)data = ((*(u64 *)data) & 0xffffff0000000000) |
1121 ((vcpu->arch.gprs[rt] >> 24) & 0xffffffffff);
1122 break;
1123 case 5:
1124 *(u64 *)data = ((*(u64 *)data) & 0xffff000000000000) |
1125 ((vcpu->arch.gprs[rt] >> 16) & 0xffffffffffff);
1126 break;
1127 case 6:
1128 *(u64 *)data = ((*(u64 *)data) & 0xff00000000000000) |
1129 ((vcpu->arch.gprs[rt] >> 8) & 0xffffffffffffff);
1130 break;
1131 case 7:
1132 *(u64 *)data = vcpu->arch.gprs[rt];
1133 break;
1134 default:
1135 break;
1136 }
1137
1138 kvm_debug("[%#lx] OP_SDL: eaddr: %#lx, gpr: %#lx, data: %llx\n",
1139 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1140 vcpu->arch.gprs[rt], *(u64 *)data);
1141 break;
1142
1143 case sdr_op:
1144 run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
1145 vcpu->arch.host_cp0_badvaddr) & (~0x7);
1146
1147 run->mmio.len = 8;
1148 imme = vcpu->arch.host_cp0_badvaddr & 0x7;
1149 switch (imme) {
1150 case 0:
1151 *(u64 *)data = vcpu->arch.gprs[rt];
1152 break;
1153 case 1:
1154 *(u64 *)data = ((*(u64 *)data) & 0xff) |
1155 (vcpu->arch.gprs[rt] << 8);
1156 break;
1157 case 2:
1158 *(u64 *)data = ((*(u64 *)data) & 0xffff) |
1159 (vcpu->arch.gprs[rt] << 16);
1160 break;
1161 case 3:
1162 *(u64 *)data = ((*(u64 *)data) & 0xffffff) |
1163 (vcpu->arch.gprs[rt] << 24);
1164 break;
1165 case 4:
1166 *(u64 *)data = ((*(u64 *)data) & 0xffffffff) |
1167 (vcpu->arch.gprs[rt] << 32);
1168 break;
1169 case 5:
1170 *(u64 *)data = ((*(u64 *)data) & 0xffffffffff) |
1171 (vcpu->arch.gprs[rt] << 40);
1172 break;
1173 case 6:
1174 *(u64 *)data = ((*(u64 *)data) & 0xffffffffffff) |
1175 (vcpu->arch.gprs[rt] << 48);
1176 break;
1177 case 7:
1178 *(u64 *)data = ((*(u64 *)data) & 0xffffffffffffff) |
1179 (vcpu->arch.gprs[rt] << 56);
1180 break;
1181 default:
1182 break;
1183 }
1184
1185 kvm_debug("[%#lx] OP_SDR: eaddr: %#lx, gpr: %#lx, data: %llx\n",
1186 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1187 vcpu->arch.gprs[rt], *(u64 *)data);
1188 break;
1189 #endif
1190
1191 #ifdef CONFIG_CPU_LOONGSON64
1192 case sdc2_op:
1193 rt = inst.loongson3_lsdc2_format.rt;
1194 switch (inst.loongson3_lsdc2_format.opcode1) {
1195 /*
1196 * Loongson-3 overridden sdc2 instructions.
1197 * opcode1 instruction
1198 * 0x0 gssbx: store 1 bytes from GPR
1199 * 0x1 gsshx: store 2 bytes from GPR
1200 * 0x2 gsswx: store 4 bytes from GPR
1201 * 0x3 gssdx: store 8 bytes from GPR
1202 */
1203 case 0x0:
1204 run->mmio.len = 1;
1205 *(u8 *)data = vcpu->arch.gprs[rt];
1206
1207 kvm_debug("[%#lx] OP_GSSBX: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1208 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1209 vcpu->arch.gprs[rt], *(u8 *)data);
1210 break;
1211 case 0x1:
1212 run->mmio.len = 2;
1213 *(u16 *)data = vcpu->arch.gprs[rt];
1214
1215 kvm_debug("[%#lx] OP_GSSSHX: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1216 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1217 vcpu->arch.gprs[rt], *(u16 *)data);
1218 break;
1219 case 0x2:
1220 run->mmio.len = 4;
1221 *(u32 *)data = vcpu->arch.gprs[rt];
1222
1223 kvm_debug("[%#lx] OP_GSSWX: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1224 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1225 vcpu->arch.gprs[rt], *(u32 *)data);
1226 break;
1227 case 0x3:
1228 run->mmio.len = 8;
1229 *(u64 *)data = vcpu->arch.gprs[rt];
1230
1231 kvm_debug("[%#lx] OP_GSSDX: eaddr: %#lx, gpr: %#lx, data: %#llx\n",
1232 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1233 vcpu->arch.gprs[rt], *(u64 *)data);
1234 break;
1235 default:
1236 kvm_err("Godson Extended GS-Store not yet supported (inst=0x%08x)\n",
1237 inst.word);
1238 break;
1239 }
1240 break;
1241 #endif
1242 default:
1243 kvm_err("Store not yet supported (inst=0x%08x)\n",
1244 inst.word);
1245 goto out_fail;
1246 }
1247
1248 vcpu->mmio_needed = 1;
1249 run->mmio.is_write = 1;
1250 vcpu->mmio_is_write = 1;
1251
1252 r = kvm_io_bus_write(vcpu, KVM_MMIO_BUS,
1253 run->mmio.phys_addr, run->mmio.len, data);
1254
1255 if (!r) {
1256 vcpu->mmio_needed = 0;
1257 return EMULATE_DONE;
1258 }
1259
1260 return EMULATE_DO_MMIO;
1261
1262 out_fail:
1263 /* Rollback PC if emulation was unsuccessful */
1264 vcpu->arch.pc = curr_pc;
1265 return EMULATE_FAIL;
1266 }
1267
kvm_mips_emulate_load(union mips_instruction inst,u32 cause,struct kvm_vcpu * vcpu)1268 enum emulation_result kvm_mips_emulate_load(union mips_instruction inst,
1269 u32 cause, struct kvm_vcpu *vcpu)
1270 {
1271 struct kvm_run *run = vcpu->run;
1272 int r;
1273 enum emulation_result er;
1274 unsigned long curr_pc;
1275 u32 op, rt;
1276 unsigned int imme;
1277
1278 rt = inst.i_format.rt;
1279 op = inst.i_format.opcode;
1280
1281 /*
1282 * Find the resume PC now while we have safe and easy access to the
1283 * prior branch instruction, and save it for
1284 * kvm_mips_complete_mmio_load() to restore later.
1285 */
1286 curr_pc = vcpu->arch.pc;
1287 er = update_pc(vcpu, cause);
1288 if (er == EMULATE_FAIL)
1289 return er;
1290 vcpu->arch.io_pc = vcpu->arch.pc;
1291 vcpu->arch.pc = curr_pc;
1292
1293 vcpu->arch.io_gpr = rt;
1294
1295 run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
1296 vcpu->arch.host_cp0_badvaddr);
1297 if (run->mmio.phys_addr == KVM_INVALID_ADDR)
1298 return EMULATE_FAIL;
1299
1300 vcpu->mmio_needed = 2; /* signed */
1301 switch (op) {
1302 #if defined(CONFIG_64BIT)
1303 case ld_op:
1304 run->mmio.len = 8;
1305 break;
1306
1307 case lwu_op:
1308 vcpu->mmio_needed = 1; /* unsigned */
1309 fallthrough;
1310 #endif
1311 case lw_op:
1312 run->mmio.len = 4;
1313 break;
1314
1315 case lhu_op:
1316 vcpu->mmio_needed = 1; /* unsigned */
1317 fallthrough;
1318 case lh_op:
1319 run->mmio.len = 2;
1320 break;
1321
1322 case lbu_op:
1323 vcpu->mmio_needed = 1; /* unsigned */
1324 fallthrough;
1325 case lb_op:
1326 run->mmio.len = 1;
1327 break;
1328
1329 case lwl_op:
1330 run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
1331 vcpu->arch.host_cp0_badvaddr) & (~0x3);
1332
1333 run->mmio.len = 4;
1334 imme = vcpu->arch.host_cp0_badvaddr & 0x3;
1335 switch (imme) {
1336 case 0:
1337 vcpu->mmio_needed = 3; /* 1 byte */
1338 break;
1339 case 1:
1340 vcpu->mmio_needed = 4; /* 2 bytes */
1341 break;
1342 case 2:
1343 vcpu->mmio_needed = 5; /* 3 bytes */
1344 break;
1345 case 3:
1346 vcpu->mmio_needed = 6; /* 4 bytes */
1347 break;
1348 default:
1349 break;
1350 }
1351 break;
1352
1353 case lwr_op:
1354 run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
1355 vcpu->arch.host_cp0_badvaddr) & (~0x3);
1356
1357 run->mmio.len = 4;
1358 imme = vcpu->arch.host_cp0_badvaddr & 0x3;
1359 switch (imme) {
1360 case 0:
1361 vcpu->mmio_needed = 7; /* 4 bytes */
1362 break;
1363 case 1:
1364 vcpu->mmio_needed = 8; /* 3 bytes */
1365 break;
1366 case 2:
1367 vcpu->mmio_needed = 9; /* 2 bytes */
1368 break;
1369 case 3:
1370 vcpu->mmio_needed = 10; /* 1 byte */
1371 break;
1372 default:
1373 break;
1374 }
1375 break;
1376
1377 #if defined(CONFIG_64BIT)
1378 case ldl_op:
1379 run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
1380 vcpu->arch.host_cp0_badvaddr) & (~0x7);
1381
1382 run->mmio.len = 8;
1383 imme = vcpu->arch.host_cp0_badvaddr & 0x7;
1384 switch (imme) {
1385 case 0:
1386 vcpu->mmio_needed = 11; /* 1 byte */
1387 break;
1388 case 1:
1389 vcpu->mmio_needed = 12; /* 2 bytes */
1390 break;
1391 case 2:
1392 vcpu->mmio_needed = 13; /* 3 bytes */
1393 break;
1394 case 3:
1395 vcpu->mmio_needed = 14; /* 4 bytes */
1396 break;
1397 case 4:
1398 vcpu->mmio_needed = 15; /* 5 bytes */
1399 break;
1400 case 5:
1401 vcpu->mmio_needed = 16; /* 6 bytes */
1402 break;
1403 case 6:
1404 vcpu->mmio_needed = 17; /* 7 bytes */
1405 break;
1406 case 7:
1407 vcpu->mmio_needed = 18; /* 8 bytes */
1408 break;
1409 default:
1410 break;
1411 }
1412 break;
1413
1414 case ldr_op:
1415 run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(
1416 vcpu->arch.host_cp0_badvaddr) & (~0x7);
1417
1418 run->mmio.len = 8;
1419 imme = vcpu->arch.host_cp0_badvaddr & 0x7;
1420 switch (imme) {
1421 case 0:
1422 vcpu->mmio_needed = 19; /* 8 bytes */
1423 break;
1424 case 1:
1425 vcpu->mmio_needed = 20; /* 7 bytes */
1426 break;
1427 case 2:
1428 vcpu->mmio_needed = 21; /* 6 bytes */
1429 break;
1430 case 3:
1431 vcpu->mmio_needed = 22; /* 5 bytes */
1432 break;
1433 case 4:
1434 vcpu->mmio_needed = 23; /* 4 bytes */
1435 break;
1436 case 5:
1437 vcpu->mmio_needed = 24; /* 3 bytes */
1438 break;
1439 case 6:
1440 vcpu->mmio_needed = 25; /* 2 bytes */
1441 break;
1442 case 7:
1443 vcpu->mmio_needed = 26; /* 1 byte */
1444 break;
1445 default:
1446 break;
1447 }
1448 break;
1449 #endif
1450
1451 #ifdef CONFIG_CPU_LOONGSON64
1452 case ldc2_op:
1453 rt = inst.loongson3_lsdc2_format.rt;
1454 switch (inst.loongson3_lsdc2_format.opcode1) {
1455 /*
1456 * Loongson-3 overridden ldc2 instructions.
1457 * opcode1 instruction
1458 * 0x0 gslbx: store 1 bytes from GPR
1459 * 0x1 gslhx: store 2 bytes from GPR
1460 * 0x2 gslwx: store 4 bytes from GPR
1461 * 0x3 gsldx: store 8 bytes from GPR
1462 */
1463 case 0x0:
1464 run->mmio.len = 1;
1465 vcpu->mmio_needed = 27; /* signed */
1466 break;
1467 case 0x1:
1468 run->mmio.len = 2;
1469 vcpu->mmio_needed = 28; /* signed */
1470 break;
1471 case 0x2:
1472 run->mmio.len = 4;
1473 vcpu->mmio_needed = 29; /* signed */
1474 break;
1475 case 0x3:
1476 run->mmio.len = 8;
1477 vcpu->mmio_needed = 30; /* signed */
1478 break;
1479 default:
1480 kvm_err("Godson Extended GS-Load for float not yet supported (inst=0x%08x)\n",
1481 inst.word);
1482 break;
1483 }
1484 break;
1485 #endif
1486
1487 default:
1488 kvm_err("Load not yet supported (inst=0x%08x)\n",
1489 inst.word);
1490 vcpu->mmio_needed = 0;
1491 return EMULATE_FAIL;
1492 }
1493
1494 run->mmio.is_write = 0;
1495 vcpu->mmio_is_write = 0;
1496
1497 r = kvm_io_bus_read(vcpu, KVM_MMIO_BUS,
1498 run->mmio.phys_addr, run->mmio.len, run->mmio.data);
1499
1500 if (!r) {
1501 kvm_mips_complete_mmio_load(vcpu);
1502 vcpu->mmio_needed = 0;
1503 return EMULATE_DONE;
1504 }
1505
1506 return EMULATE_DO_MMIO;
1507 }
1508
kvm_mips_complete_mmio_load(struct kvm_vcpu * vcpu)1509 enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu)
1510 {
1511 struct kvm_run *run = vcpu->run;
1512 unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
1513 enum emulation_result er = EMULATE_DONE;
1514
1515 if (run->mmio.len > sizeof(*gpr)) {
1516 kvm_err("Bad MMIO length: %d", run->mmio.len);
1517 er = EMULATE_FAIL;
1518 goto done;
1519 }
1520
1521 /* Restore saved resume PC */
1522 vcpu->arch.pc = vcpu->arch.io_pc;
1523
1524 switch (run->mmio.len) {
1525 case 8:
1526 switch (vcpu->mmio_needed) {
1527 case 11:
1528 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffffffffffff) |
1529 (((*(s64 *)run->mmio.data) & 0xff) << 56);
1530 break;
1531 case 12:
1532 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffffffffff) |
1533 (((*(s64 *)run->mmio.data) & 0xffff) << 48);
1534 break;
1535 case 13:
1536 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffffffff) |
1537 (((*(s64 *)run->mmio.data) & 0xffffff) << 40);
1538 break;
1539 case 14:
1540 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffffff) |
1541 (((*(s64 *)run->mmio.data) & 0xffffffff) << 32);
1542 break;
1543 case 15:
1544 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffff) |
1545 (((*(s64 *)run->mmio.data) & 0xffffffffff) << 24);
1546 break;
1547 case 16:
1548 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffff) |
1549 (((*(s64 *)run->mmio.data) & 0xffffffffffff) << 16);
1550 break;
1551 case 17:
1552 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xff) |
1553 (((*(s64 *)run->mmio.data) & 0xffffffffffffff) << 8);
1554 break;
1555 case 18:
1556 case 19:
1557 *gpr = *(s64 *)run->mmio.data;
1558 break;
1559 case 20:
1560 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xff00000000000000) |
1561 ((((*(s64 *)run->mmio.data)) >> 8) & 0xffffffffffffff);
1562 break;
1563 case 21:
1564 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffff000000000000) |
1565 ((((*(s64 *)run->mmio.data)) >> 16) & 0xffffffffffff);
1566 break;
1567 case 22:
1568 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffff0000000000) |
1569 ((((*(s64 *)run->mmio.data)) >> 24) & 0xffffffffff);
1570 break;
1571 case 23:
1572 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffffff00000000) |
1573 ((((*(s64 *)run->mmio.data)) >> 32) & 0xffffffff);
1574 break;
1575 case 24:
1576 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffffffff000000) |
1577 ((((*(s64 *)run->mmio.data)) >> 40) & 0xffffff);
1578 break;
1579 case 25:
1580 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffffffffff0000) |
1581 ((((*(s64 *)run->mmio.data)) >> 48) & 0xffff);
1582 break;
1583 case 26:
1584 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffffffffffff00) |
1585 ((((*(s64 *)run->mmio.data)) >> 56) & 0xff);
1586 break;
1587 default:
1588 *gpr = *(s64 *)run->mmio.data;
1589 }
1590 break;
1591
1592 case 4:
1593 switch (vcpu->mmio_needed) {
1594 case 1:
1595 *gpr = *(u32 *)run->mmio.data;
1596 break;
1597 case 2:
1598 *gpr = *(s32 *)run->mmio.data;
1599 break;
1600 case 3:
1601 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffff) |
1602 (((*(s32 *)run->mmio.data) & 0xff) << 24);
1603 break;
1604 case 4:
1605 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffff) |
1606 (((*(s32 *)run->mmio.data) & 0xffff) << 16);
1607 break;
1608 case 5:
1609 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xff) |
1610 (((*(s32 *)run->mmio.data) & 0xffffff) << 8);
1611 break;
1612 case 6:
1613 case 7:
1614 *gpr = *(s32 *)run->mmio.data;
1615 break;
1616 case 8:
1617 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xff000000) |
1618 ((((*(s32 *)run->mmio.data)) >> 8) & 0xffffff);
1619 break;
1620 case 9:
1621 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffff0000) |
1622 ((((*(s32 *)run->mmio.data)) >> 16) & 0xffff);
1623 break;
1624 case 10:
1625 *gpr = (vcpu->arch.gprs[vcpu->arch.io_gpr] & 0xffffff00) |
1626 ((((*(s32 *)run->mmio.data)) >> 24) & 0xff);
1627 break;
1628 default:
1629 *gpr = *(s32 *)run->mmio.data;
1630 }
1631 break;
1632
1633 case 2:
1634 if (vcpu->mmio_needed == 1)
1635 *gpr = *(u16 *)run->mmio.data;
1636 else
1637 *gpr = *(s16 *)run->mmio.data;
1638
1639 break;
1640 case 1:
1641 if (vcpu->mmio_needed == 1)
1642 *gpr = *(u8 *)run->mmio.data;
1643 else
1644 *gpr = *(s8 *)run->mmio.data;
1645 break;
1646 }
1647
1648 done:
1649 return er;
1650 }
1651