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Merge tag 'fixes-for-v4.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi...
[linux/fpc-iii.git] / arch / mips / kvm / emulate.c
blobfb3e8dfd1ff647263c0ca93a1d2ba6c5fdbd906b
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/module.h>
17 #include <linux/vmalloc.h>
18 #include <linux/fs.h>
19 #include <linux/bootmem.h>
20 #include <linux/random.h>
21 #include <asm/page.h>
22 #include <asm/cacheflush.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 "opcode.h"
33 #include "interrupt.h"
34 #include "commpage.h"
35
36 #include "trace.h"
37
38 /*
39 * Compute the return address and do emulate branch simulation, if required.
40 * This function should be called only in branch delay slot active.
41 */
42 unsigned long kvm_compute_return_epc(struct kvm_vcpu *vcpu,
43 unsigned long instpc)
44 {
45 unsigned int dspcontrol;
46 union mips_instruction insn;
47 struct kvm_vcpu_arch *arch = &vcpu->arch;
48 long epc = instpc;
49 long nextpc = KVM_INVALID_INST;
50
51 if (epc & 3)
52 goto unaligned;
53
54 /* Read the instruction */
55 insn.word = kvm_get_inst((uint32_t *) epc, vcpu);
56
57 if (insn.word == KVM_INVALID_INST)
58 return KVM_INVALID_INST;
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 /* Fall through */
67 case jr_op:
68 nextpc = arch->gprs[insn.r_format.rs];
69 break;
70 }
71 break;
72
73 /*
74 * This group contains:
75 * bltz_op, bgez_op, bltzl_op, bgezl_op,
76 * bltzal_op, bgezal_op, bltzall_op, bgezall_op.
77 */
78 case bcond_op:
79 switch (insn.i_format.rt) {
80 case bltz_op:
81 case bltzl_op:
82 if ((long)arch->gprs[insn.i_format.rs] < 0)
83 epc = epc + 4 + (insn.i_format.simmediate << 2);
84 else
85 epc += 8;
86 nextpc = epc;
87 break;
88
89 case bgez_op:
90 case bgezl_op:
91 if ((long)arch->gprs[insn.i_format.rs] >= 0)
92 epc = epc + 4 + (insn.i_format.simmediate << 2);
93 else
94 epc += 8;
95 nextpc = epc;
96 break;
97
98 case bltzal_op:
99 case bltzall_op:
100 arch->gprs[31] = epc + 8;
101 if ((long)arch->gprs[insn.i_format.rs] < 0)
102 epc = epc + 4 + (insn.i_format.simmediate << 2);
103 else
104 epc += 8;
105 nextpc = epc;
106 break;
107
108 case bgezal_op:
109 case bgezall_op:
110 arch->gprs[31] = epc + 8;
111 if ((long)arch->gprs[insn.i_format.rs] >= 0)
112 epc = epc + 4 + (insn.i_format.simmediate << 2);
113 else
114 epc += 8;
115 nextpc = epc;
116 break;
117 case bposge32_op:
118 if (!cpu_has_dsp)
119 goto sigill;
120
121 dspcontrol = rddsp(0x01);
122
123 if (dspcontrol >= 32)
124 epc = epc + 4 + (insn.i_format.simmediate << 2);
125 else
126 epc += 8;
127 nextpc = epc;
128 break;
129 }
130 break;
131
132 /* These are unconditional and in j_format. */
133 case jal_op:
134 arch->gprs[31] = instpc + 8;
135 case j_op:
136 epc += 4;
137 epc >>= 28;
138 epc <<= 28;
139 epc |= (insn.j_format.target << 2);
140 nextpc = epc;
141 break;
142
143 /* These are conditional and in i_format. */
144 case beq_op:
145 case beql_op:
146 if (arch->gprs[insn.i_format.rs] ==
147 arch->gprs[insn.i_format.rt])
148 epc = epc + 4 + (insn.i_format.simmediate << 2);
149 else
150 epc += 8;
151 nextpc = epc;
152 break;
153
154 case bne_op:
155 case bnel_op:
156 if (arch->gprs[insn.i_format.rs] !=
157 arch->gprs[insn.i_format.rt])
158 epc = epc + 4 + (insn.i_format.simmediate << 2);
159 else
160 epc += 8;
161 nextpc = epc;
162 break;
163
164 case blez_op: /* not really i_format */
165 case blezl_op:
166 /* rt field assumed to be zero */
167 if ((long)arch->gprs[insn.i_format.rs] <= 0)
168 epc = epc + 4 + (insn.i_format.simmediate << 2);
169 else
170 epc += 8;
171 nextpc = epc;
172 break;
173
174 case bgtz_op:
175 case bgtzl_op:
176 /* rt field assumed to be zero */
177 if ((long)arch->gprs[insn.i_format.rs] > 0)
178 epc = epc + 4 + (insn.i_format.simmediate << 2);
179 else
180 epc += 8;
181 nextpc = epc;
182 break;
183
184 /* And now the FPA/cp1 branch instructions. */
185 case cop1_op:
186 kvm_err("%s: unsupported cop1_op\n", __func__);
187 break;
188 }
189
190 return nextpc;
191
192 unaligned:
193 kvm_err("%s: unaligned epc\n", __func__);
194 return nextpc;
195
196 sigill:
197 kvm_err("%s: DSP branch but not DSP ASE\n", __func__);
198 return nextpc;
199 }
200
201 enum emulation_result update_pc(struct kvm_vcpu *vcpu, uint32_t cause)
202 {
203 unsigned long branch_pc;
204 enum emulation_result er = EMULATE_DONE;
205
206 if (cause & CAUSEF_BD) {
207 branch_pc = kvm_compute_return_epc(vcpu, vcpu->arch.pc);
208 if (branch_pc == KVM_INVALID_INST) {
209 er = EMULATE_FAIL;
210 } else {
211 vcpu->arch.pc = branch_pc;
212 kvm_debug("BD update_pc(): New PC: %#lx\n",
213 vcpu->arch.pc);
214 }
215 } else
216 vcpu->arch.pc += 4;
217
218 kvm_debug("update_pc(): New PC: %#lx\n", vcpu->arch.pc);
219
220 return er;
221 }
222
223 /**
224 * kvm_mips_count_disabled() - Find whether the CP0_Count timer is disabled.
225 * @vcpu: Virtual CPU.
226 *
227 * Returns: 1 if the CP0_Count timer is disabled by either the guest
228 * CP0_Cause.DC bit or the count_ctl.DC bit.
229 * 0 otherwise (in which case CP0_Count timer is running).
230 */
231 static inline int kvm_mips_count_disabled(struct kvm_vcpu *vcpu)
232 {
233 struct mips_coproc *cop0 = vcpu->arch.cop0;
234
235 return (vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) ||
236 (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC);
237 }
238
239 /**
240 * kvm_mips_ktime_to_count() - Scale ktime_t to a 32-bit count.
241 *
242 * Caches the dynamic nanosecond bias in vcpu->arch.count_dyn_bias.
243 *
244 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
245 */
246 static uint32_t kvm_mips_ktime_to_count(struct kvm_vcpu *vcpu, ktime_t now)
247 {
248 s64 now_ns, periods;
249 u64 delta;
250
251 now_ns = ktime_to_ns(now);
252 delta = now_ns + vcpu->arch.count_dyn_bias;
253
254 if (delta >= vcpu->arch.count_period) {
255 /* If delta is out of safe range the bias needs adjusting */
256 periods = div64_s64(now_ns, vcpu->arch.count_period);
257 vcpu->arch.count_dyn_bias = -periods * vcpu->arch.count_period;
258 /* Recalculate delta with new bias */
259 delta = now_ns + vcpu->arch.count_dyn_bias;
260 }
261
262 /*
263 * We've ensured that:
264 * delta < count_period
265 *
266 * Therefore the intermediate delta*count_hz will never overflow since
267 * at the boundary condition:
268 * delta = count_period
269 * delta = NSEC_PER_SEC * 2^32 / count_hz
270 * delta * count_hz = NSEC_PER_SEC * 2^32
271 */
272 return div_u64(delta * vcpu->arch.count_hz, NSEC_PER_SEC);
273 }
274
275 /**
276 * kvm_mips_count_time() - Get effective current time.
277 * @vcpu: Virtual CPU.
278 *
279 * Get effective monotonic ktime. This is usually a straightforward ktime_get(),
280 * except when the master disable bit is set in count_ctl, in which case it is
281 * count_resume, i.e. the time that the count was disabled.
282 *
283 * Returns: Effective monotonic ktime for CP0_Count.
284 */
285 static inline ktime_t kvm_mips_count_time(struct kvm_vcpu *vcpu)
286 {
287 if (unlikely(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC))
288 return vcpu->arch.count_resume;
289
290 return ktime_get();
291 }
292
293 /**
294 * kvm_mips_read_count_running() - Read the current count value as if running.
295 * @vcpu: Virtual CPU.
296 * @now: Kernel time to read CP0_Count at.
297 *
298 * Returns the current guest CP0_Count register at time @now and handles if the
299 * timer interrupt is pending and hasn't been handled yet.
300 *
301 * Returns: The current value of the guest CP0_Count register.
302 */
303 static uint32_t kvm_mips_read_count_running(struct kvm_vcpu *vcpu, ktime_t now)
304 {
305 ktime_t expires;
306 int running;
307
308 /* Is the hrtimer pending? */
309 expires = hrtimer_get_expires(&vcpu->arch.comparecount_timer);
310 if (ktime_compare(now, expires) >= 0) {
311 /*
312 * Cancel it while we handle it so there's no chance of
313 * interference with the timeout handler.
314 */
315 running = hrtimer_cancel(&vcpu->arch.comparecount_timer);
316
317 /* Nothing should be waiting on the timeout */
318 kvm_mips_callbacks->queue_timer_int(vcpu);
319
320 /*
321 * Restart the timer if it was running based on the expiry time
322 * we read, so that we don't push it back 2 periods.
323 */
324 if (running) {
325 expires = ktime_add_ns(expires,
326 vcpu->arch.count_period);
327 hrtimer_start(&vcpu->arch.comparecount_timer, expires,
328 HRTIMER_MODE_ABS);
329 }
330 }
331
332 /* Return the biased and scaled guest CP0_Count */
333 return vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now);
334 }
335
336 /**
337 * kvm_mips_read_count() - Read the current count value.
338 * @vcpu: Virtual CPU.
339 *
340 * Read the current guest CP0_Count value, taking into account whether the timer
341 * is stopped.
342 *
343 * Returns: The current guest CP0_Count value.
344 */
345 uint32_t kvm_mips_read_count(struct kvm_vcpu *vcpu)
346 {
347 struct mips_coproc *cop0 = vcpu->arch.cop0;
348
349 /* If count disabled just read static copy of count */
350 if (kvm_mips_count_disabled(vcpu))
351 return kvm_read_c0_guest_count(cop0);
352
353 return kvm_mips_read_count_running(vcpu, ktime_get());
354 }
355
356 /**
357 * kvm_mips_freeze_hrtimer() - Safely stop the hrtimer.
358 * @vcpu: Virtual CPU.
359 * @count: Output pointer for CP0_Count value at point of freeze.
360 *
361 * Freeze the hrtimer safely and return both the ktime and the CP0_Count value
362 * at the point it was frozen. It is guaranteed that any pending interrupts at
363 * the point it was frozen are handled, and none after that point.
364 *
365 * This is useful where the time/CP0_Count is needed in the calculation of the
366 * new parameters.
367 *
368 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
369 *
370 * Returns: The ktime at the point of freeze.
371 */
372 static ktime_t kvm_mips_freeze_hrtimer(struct kvm_vcpu *vcpu,
373 uint32_t *count)
374 {
375 ktime_t now;
376
377 /* stop hrtimer before finding time */
378 hrtimer_cancel(&vcpu->arch.comparecount_timer);
379 now = ktime_get();
380
381 /* find count at this point and handle pending hrtimer */
382 *count = kvm_mips_read_count_running(vcpu, now);
383
384 return now;
385 }
386
387 /**
388 * kvm_mips_resume_hrtimer() - Resume hrtimer, updating expiry.
389 * @vcpu: Virtual CPU.
390 * @now: ktime at point of resume.
391 * @count: CP0_Count at point of resume.
392 *
393 * Resumes the timer and updates the timer expiry based on @now and @count.
394 * This can be used in conjunction with kvm_mips_freeze_timer() when timer
395 * parameters need to be changed.
396 *
397 * It is guaranteed that a timer interrupt immediately after resume will be
398 * handled, but not if CP_Compare is exactly at @count. That case is already
399 * handled by kvm_mips_freeze_timer().
400 *
401 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
402 */
403 static void kvm_mips_resume_hrtimer(struct kvm_vcpu *vcpu,
404 ktime_t now, uint32_t count)
405 {
406 struct mips_coproc *cop0 = vcpu->arch.cop0;
407 uint32_t compare;
408 u64 delta;
409 ktime_t expire;
410
411 /* Calculate timeout (wrap 0 to 2^32) */
412 compare = kvm_read_c0_guest_compare(cop0);
413 delta = (u64)(uint32_t)(compare - count - 1) + 1;
414 delta = div_u64(delta * NSEC_PER_SEC, vcpu->arch.count_hz);
415 expire = ktime_add_ns(now, delta);
416
417 /* Update hrtimer to use new timeout */
418 hrtimer_cancel(&vcpu->arch.comparecount_timer);
419 hrtimer_start(&vcpu->arch.comparecount_timer, expire, HRTIMER_MODE_ABS);
420 }
421
422 /**
423 * kvm_mips_update_hrtimer() - Update next expiry time of hrtimer.
424 * @vcpu: Virtual CPU.
425 *
426 * Recalculates and updates the expiry time of the hrtimer. This can be used
427 * after timer parameters have been altered which do not depend on the time that
428 * the change occurs (in those cases kvm_mips_freeze_hrtimer() and
429 * kvm_mips_resume_hrtimer() are used directly).
430 *
431 * It is guaranteed that no timer interrupts will be lost in the process.
432 *
433 * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
434 */
435 static void kvm_mips_update_hrtimer(struct kvm_vcpu *vcpu)
436 {
437 ktime_t now;
438 uint32_t count;
439
440 /*
441 * freeze_hrtimer takes care of a timer interrupts <= count, and
442 * resume_hrtimer the hrtimer takes care of a timer interrupts > count.
443 */
444 now = kvm_mips_freeze_hrtimer(vcpu, &count);
445 kvm_mips_resume_hrtimer(vcpu, now, count);
446 }
447
448 /**
449 * kvm_mips_write_count() - Modify the count and update timer.
450 * @vcpu: Virtual CPU.
451 * @count: Guest CP0_Count value to set.
452 *
453 * Sets the CP0_Count value and updates the timer accordingly.
454 */
455 void kvm_mips_write_count(struct kvm_vcpu *vcpu, uint32_t count)
456 {
457 struct mips_coproc *cop0 = vcpu->arch.cop0;
458 ktime_t now;
459
460 /* Calculate bias */
461 now = kvm_mips_count_time(vcpu);
462 vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now);
463
464 if (kvm_mips_count_disabled(vcpu))
465 /* The timer's disabled, adjust the static count */
466 kvm_write_c0_guest_count(cop0, count);
467 else
468 /* Update timeout */
469 kvm_mips_resume_hrtimer(vcpu, now, count);
470 }
471
472 /**
473 * kvm_mips_init_count() - Initialise timer.
474 * @vcpu: Virtual CPU.
475 *
476 * Initialise the timer to a sensible frequency, namely 100MHz, zero it, and set
477 * it going if it's enabled.
478 */
479 void kvm_mips_init_count(struct kvm_vcpu *vcpu)
480 {
481 /* 100 MHz */
482 vcpu->arch.count_hz = 100*1000*1000;
483 vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32,
484 vcpu->arch.count_hz);
485 vcpu->arch.count_dyn_bias = 0;
486
487 /* Starting at 0 */
488 kvm_mips_write_count(vcpu, 0);
489 }
490
491 /**
492 * kvm_mips_set_count_hz() - Update the frequency of the timer.
493 * @vcpu: Virtual CPU.
494 * @count_hz: Frequency of CP0_Count timer in Hz.
495 *
496 * Change the frequency of the CP0_Count timer. This is done atomically so that
497 * CP0_Count is continuous and no timer interrupt is lost.
498 *
499 * Returns: -EINVAL if @count_hz is out of range.
500 * 0 on success.
501 */
502 int kvm_mips_set_count_hz(struct kvm_vcpu *vcpu, s64 count_hz)
503 {
504 struct mips_coproc *cop0 = vcpu->arch.cop0;
505 int dc;
506 ktime_t now;
507 u32 count;
508
509 /* ensure the frequency is in a sensible range... */
510 if (count_hz <= 0 || count_hz > NSEC_PER_SEC)
511 return -EINVAL;
512 /* ... and has actually changed */
513 if (vcpu->arch.count_hz == count_hz)
514 return 0;
515
516 /* Safely freeze timer so we can keep it continuous */
517 dc = kvm_mips_count_disabled(vcpu);
518 if (dc) {
519 now = kvm_mips_count_time(vcpu);
520 count = kvm_read_c0_guest_count(cop0);
521 } else {
522 now = kvm_mips_freeze_hrtimer(vcpu, &count);
523 }
524
525 /* Update the frequency */
526 vcpu->arch.count_hz = count_hz;
527 vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32, count_hz);
528 vcpu->arch.count_dyn_bias = 0;
529
530 /* Calculate adjusted bias so dynamic count is unchanged */
531 vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now);
532
533 /* Update and resume hrtimer */
534 if (!dc)
535 kvm_mips_resume_hrtimer(vcpu, now, count);
536 return 0;
537 }
538
539 /**
540 * kvm_mips_write_compare() - Modify compare and update timer.
541 * @vcpu: Virtual CPU.
542 * @compare: New CP0_Compare value.
543 *
544 * Update CP0_Compare to a new value and update the timeout.
545 */
546 void kvm_mips_write_compare(struct kvm_vcpu *vcpu, uint32_t compare)
547 {
548 struct mips_coproc *cop0 = vcpu->arch.cop0;
549
550 /* if unchanged, must just be an ack */
551 if (kvm_read_c0_guest_compare(cop0) == compare)
552 return;
553
554 /* Update compare */
555 kvm_write_c0_guest_compare(cop0, compare);
556
557 /* Update timeout if count enabled */
558 if (!kvm_mips_count_disabled(vcpu))
559 kvm_mips_update_hrtimer(vcpu);
560 }
561
562 /**
563 * kvm_mips_count_disable() - Disable count.
564 * @vcpu: Virtual CPU.
565 *
566 * Disable the CP0_Count timer. A timer interrupt on or before the final stop
567 * time will be handled but not after.
568 *
569 * Assumes CP0_Count was previously enabled but now Guest.CP0_Cause.DC or
570 * count_ctl.DC has been set (count disabled).
571 *
572 * Returns: The time that the timer was stopped.
573 */
574 static ktime_t kvm_mips_count_disable(struct kvm_vcpu *vcpu)
575 {
576 struct mips_coproc *cop0 = vcpu->arch.cop0;
577 uint32_t count;
578 ktime_t now;
579
580 /* Stop hrtimer */
581 hrtimer_cancel(&vcpu->arch.comparecount_timer);
582
583 /* Set the static count from the dynamic count, handling pending TI */
584 now = ktime_get();
585 count = kvm_mips_read_count_running(vcpu, now);
586 kvm_write_c0_guest_count(cop0, count);
587
588 return now;
589 }
590
591 /**
592 * kvm_mips_count_disable_cause() - Disable count using CP0_Cause.DC.
593 * @vcpu: Virtual CPU.
594 *
595 * Disable the CP0_Count timer and set CP0_Cause.DC. A timer interrupt on or
596 * before the final stop time will be handled if the timer isn't disabled by
597 * count_ctl.DC, but not after.
598 *
599 * Assumes CP0_Cause.DC is clear (count enabled).
600 */
601 void kvm_mips_count_disable_cause(struct kvm_vcpu *vcpu)
602 {
603 struct mips_coproc *cop0 = vcpu->arch.cop0;
604
605 kvm_set_c0_guest_cause(cop0, CAUSEF_DC);
606 if (!(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC))
607 kvm_mips_count_disable(vcpu);
608 }
609
610 /**
611 * kvm_mips_count_enable_cause() - Enable count using CP0_Cause.DC.
612 * @vcpu: Virtual CPU.
613 *
614 * Enable the CP0_Count timer and clear CP0_Cause.DC. A timer interrupt after
615 * the start time will be handled if the timer isn't disabled by count_ctl.DC,
616 * potentially before even returning, so the caller should be careful with
617 * ordering of CP0_Cause modifications so as not to lose it.
618 *
619 * Assumes CP0_Cause.DC is set (count disabled).
620 */
621 void kvm_mips_count_enable_cause(struct kvm_vcpu *vcpu)
622 {
623 struct mips_coproc *cop0 = vcpu->arch.cop0;
624 uint32_t count;
625
626 kvm_clear_c0_guest_cause(cop0, CAUSEF_DC);
627
628 /*
629 * Set the dynamic count to match the static count.
630 * This starts the hrtimer if count_ctl.DC allows it.
631 * Otherwise it conveniently updates the biases.
632 */
633 count = kvm_read_c0_guest_count(cop0);
634 kvm_mips_write_count(vcpu, count);
635 }
636
637 /**
638 * kvm_mips_set_count_ctl() - Update the count control KVM register.
639 * @vcpu: Virtual CPU.
640 * @count_ctl: Count control register new value.
641 *
642 * Set the count control KVM register. The timer is updated accordingly.
643 *
644 * Returns: -EINVAL if reserved bits are set.
645 * 0 on success.
646 */
647 int kvm_mips_set_count_ctl(struct kvm_vcpu *vcpu, s64 count_ctl)
648 {
649 struct mips_coproc *cop0 = vcpu->arch.cop0;
650 s64 changed = count_ctl ^ vcpu->arch.count_ctl;
651 s64 delta;
652 ktime_t expire, now;
653 uint32_t count, compare;
654
655 /* Only allow defined bits to be changed */
656 if (changed & ~(s64)(KVM_REG_MIPS_COUNT_CTL_DC))
657 return -EINVAL;
658
659 /* Apply new value */
660 vcpu->arch.count_ctl = count_ctl;
661
662 /* Master CP0_Count disable */
663 if (changed & KVM_REG_MIPS_COUNT_CTL_DC) {
664 /* Is CP0_Cause.DC already disabling CP0_Count? */
665 if (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC) {
666 if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC)
667 /* Just record the current time */
668 vcpu->arch.count_resume = ktime_get();
669 } else if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) {
670 /* disable timer and record current time */
671 vcpu->arch.count_resume = kvm_mips_count_disable(vcpu);
672 } else {
673 /*
674 * Calculate timeout relative to static count at resume
675 * time (wrap 0 to 2^32).
676 */
677 count = kvm_read_c0_guest_count(cop0);
678 compare = kvm_read_c0_guest_compare(cop0);
679 delta = (u64)(uint32_t)(compare - count - 1) + 1;
680 delta = div_u64(delta * NSEC_PER_SEC,
681 vcpu->arch.count_hz);
682 expire = ktime_add_ns(vcpu->arch.count_resume, delta);
683
684 /* Handle pending interrupt */
685 now = ktime_get();
686 if (ktime_compare(now, expire) >= 0)
687 /* Nothing should be waiting on the timeout */
688 kvm_mips_callbacks->queue_timer_int(vcpu);
689
690 /* Resume hrtimer without changing bias */
691 count = kvm_mips_read_count_running(vcpu, now);
692 kvm_mips_resume_hrtimer(vcpu, now, count);
693 }
694 }
695
696 return 0;
697 }
698
699 /**
700 * kvm_mips_set_count_resume() - Update the count resume KVM register.
701 * @vcpu: Virtual CPU.
702 * @count_resume: Count resume register new value.
703 *
704 * Set the count resume KVM register.
705 *
706 * Returns: -EINVAL if out of valid range (0..now).
707 * 0 on success.
708 */
709 int kvm_mips_set_count_resume(struct kvm_vcpu *vcpu, s64 count_resume)
710 {
711 /*
712 * It doesn't make sense for the resume time to be in the future, as it
713 * would be possible for the next interrupt to be more than a full
714 * period in the future.
715 */
716 if (count_resume < 0 || count_resume > ktime_to_ns(ktime_get()))
717 return -EINVAL;
718
719 vcpu->arch.count_resume = ns_to_ktime(count_resume);
720 return 0;
721 }
722
723 /**
724 * kvm_mips_count_timeout() - Push timer forward on timeout.
725 * @vcpu: Virtual CPU.
726 *
727 * Handle an hrtimer event by push the hrtimer forward a period.
728 *
729 * Returns: The hrtimer_restart value to return to the hrtimer subsystem.
730 */
731 enum hrtimer_restart kvm_mips_count_timeout(struct kvm_vcpu *vcpu)
732 {
733 /* Add the Count period to the current expiry time */
734 hrtimer_add_expires_ns(&vcpu->arch.comparecount_timer,
735 vcpu->arch.count_period);
736 return HRTIMER_RESTART;
737 }
738
739 enum emulation_result kvm_mips_emul_eret(struct kvm_vcpu *vcpu)
740 {
741 struct mips_coproc *cop0 = vcpu->arch.cop0;
742 enum emulation_result er = EMULATE_DONE;
743
744 if (kvm_read_c0_guest_status(cop0) & ST0_EXL) {
745 kvm_debug("[%#lx] ERET to %#lx\n", vcpu->arch.pc,
746 kvm_read_c0_guest_epc(cop0));
747 kvm_clear_c0_guest_status(cop0, ST0_EXL);
748 vcpu->arch.pc = kvm_read_c0_guest_epc(cop0);
749
750 } else if (kvm_read_c0_guest_status(cop0) & ST0_ERL) {
751 kvm_clear_c0_guest_status(cop0, ST0_ERL);
752 vcpu->arch.pc = kvm_read_c0_guest_errorepc(cop0);
753 } else {
754 kvm_err("[%#lx] ERET when MIPS_SR_EXL|MIPS_SR_ERL == 0\n",
755 vcpu->arch.pc);
756 er = EMULATE_FAIL;
757 }
758
759 return er;
760 }
761
762 enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
763 {
764 kvm_debug("[%#lx] !!!WAIT!!! (%#lx)\n", vcpu->arch.pc,
765 vcpu->arch.pending_exceptions);
766
767 ++vcpu->stat.wait_exits;
768 trace_kvm_exit(vcpu, WAIT_EXITS);
769 if (!vcpu->arch.pending_exceptions) {
770 vcpu->arch.wait = 1;
771 kvm_vcpu_block(vcpu);
772
773 /*
774 * We we are runnable, then definitely go off to user space to
775 * check if any I/O interrupts are pending.
776 */
777 if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
778 clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
779 vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
780 }
781 }
782
783 return EMULATE_DONE;
784 }
785
786 /*
787 * XXXKYMA: Linux doesn't seem to use TLBR, return EMULATE_FAIL for now so that
788 * we can catch this, if things ever change
789 */
790 enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu)
791 {
792 struct mips_coproc *cop0 = vcpu->arch.cop0;
793 uint32_t pc = vcpu->arch.pc;
794
795 kvm_err("[%#x] COP0_TLBR [%ld]\n", pc, kvm_read_c0_guest_index(cop0));
796 return EMULATE_FAIL;
797 }
798
799 /* Write Guest TLB Entry @ Index */
800 enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu)
801 {
802 struct mips_coproc *cop0 = vcpu->arch.cop0;
803 int index = kvm_read_c0_guest_index(cop0);
804 struct kvm_mips_tlb *tlb = NULL;
805 uint32_t pc = vcpu->arch.pc;
806
807 if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) {
808 kvm_debug("%s: illegal index: %d\n", __func__, index);
809 kvm_debug("[%#x] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
810 pc, index, kvm_read_c0_guest_entryhi(cop0),
811 kvm_read_c0_guest_entrylo0(cop0),
812 kvm_read_c0_guest_entrylo1(cop0),
813 kvm_read_c0_guest_pagemask(cop0));
814 index = (index & ~0x80000000) % KVM_MIPS_GUEST_TLB_SIZE;
815 }
816
817 tlb = &vcpu->arch.guest_tlb[index];
818 /*
819 * Probe the shadow host TLB for the entry being overwritten, if one
820 * matches, invalidate it
821 */
822 kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
823
824 tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
825 tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
826 tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0);
827 tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0);
828
829 kvm_debug("[%#x] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
830 pc, index, kvm_read_c0_guest_entryhi(cop0),
831 kvm_read_c0_guest_entrylo0(cop0),
832 kvm_read_c0_guest_entrylo1(cop0),
833 kvm_read_c0_guest_pagemask(cop0));
834
835 return EMULATE_DONE;
836 }
837
838 /* Write Guest TLB Entry @ Random Index */
839 enum emulation_result kvm_mips_emul_tlbwr(struct kvm_vcpu *vcpu)
840 {
841 struct mips_coproc *cop0 = vcpu->arch.cop0;
842 struct kvm_mips_tlb *tlb = NULL;
843 uint32_t pc = vcpu->arch.pc;
844 int index;
845
846 get_random_bytes(&index, sizeof(index));
847 index &= (KVM_MIPS_GUEST_TLB_SIZE - 1);
848
849 tlb = &vcpu->arch.guest_tlb[index];
850
851 /*
852 * Probe the shadow host TLB for the entry being overwritten, if one
853 * matches, invalidate it
854 */
855 kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
856
857 tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
858 tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
859 tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0);
860 tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0);
861
862 kvm_debug("[%#x] COP0_TLBWR[%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx)\n",
863 pc, index, kvm_read_c0_guest_entryhi(cop0),
864 kvm_read_c0_guest_entrylo0(cop0),
865 kvm_read_c0_guest_entrylo1(cop0));
866
867 return EMULATE_DONE;
868 }
869
870 enum emulation_result kvm_mips_emul_tlbp(struct kvm_vcpu *vcpu)
871 {
872 struct mips_coproc *cop0 = vcpu->arch.cop0;
873 long entryhi = kvm_read_c0_guest_entryhi(cop0);
874 uint32_t pc = vcpu->arch.pc;
875 int index = -1;
876
877 index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
878
879 kvm_write_c0_guest_index(cop0, index);
880
881 kvm_debug("[%#x] COP0_TLBP (entryhi: %#lx), index: %d\n", pc, entryhi,
882 index);
883
884 return EMULATE_DONE;
885 }
886
887 enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc,
888 uint32_t cause, struct kvm_run *run,
889 struct kvm_vcpu *vcpu)
890 {
891 struct mips_coproc *cop0 = vcpu->arch.cop0;
892 enum emulation_result er = EMULATE_DONE;
893 int32_t rt, rd, copz, sel, co_bit, op;
894 uint32_t pc = vcpu->arch.pc;
895 unsigned long curr_pc;
896
897 /*
898 * Update PC and hold onto current PC in case there is
899 * an error and we want to rollback the PC
900 */
901 curr_pc = vcpu->arch.pc;
902 er = update_pc(vcpu, cause);
903 if (er == EMULATE_FAIL)
904 return er;
905
906 copz = (inst >> 21) & 0x1f;
907 rt = (inst >> 16) & 0x1f;
908 rd = (inst >> 11) & 0x1f;
909 sel = inst & 0x7;
910 co_bit = (inst >> 25) & 1;
911
912 if (co_bit) {
913 op = (inst) & 0xff;
914
915 switch (op) {
916 case tlbr_op: /* Read indexed TLB entry */
917 er = kvm_mips_emul_tlbr(vcpu);
918 break;
919 case tlbwi_op: /* Write indexed */
920 er = kvm_mips_emul_tlbwi(vcpu);
921 break;
922 case tlbwr_op: /* Write random */
923 er = kvm_mips_emul_tlbwr(vcpu);
924 break;
925 case tlbp_op: /* TLB Probe */
926 er = kvm_mips_emul_tlbp(vcpu);
927 break;
928 case rfe_op:
929 kvm_err("!!!COP0_RFE!!!\n");
930 break;
931 case eret_op:
932 er = kvm_mips_emul_eret(vcpu);
933 goto dont_update_pc;
934 break;
935 case wait_op:
936 er = kvm_mips_emul_wait(vcpu);
937 break;
938 }
939 } else {
940 switch (copz) {
941 case mfc_op:
942 #ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
943 cop0->stat[rd][sel]++;
944 #endif
945 /* Get reg */
946 if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
947 vcpu->arch.gprs[rt] = kvm_mips_read_count(vcpu);
948 } else if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) {
949 vcpu->arch.gprs[rt] = 0x0;
950 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
951 kvm_mips_trans_mfc0(inst, opc, vcpu);
952 #endif
953 } else {
954 vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
955
956 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
957 kvm_mips_trans_mfc0(inst, opc, vcpu);
958 #endif
959 }
960
961 kvm_debug
962 ("[%#x] MFCz[%d][%d], vcpu->arch.gprs[%d]: %#lx\n",
963 pc, rd, sel, rt, vcpu->arch.gprs[rt]);
964
965 break;
966
967 case dmfc_op:
968 vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
969 break;
970
971 case mtc_op:
972 #ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
973 cop0->stat[rd][sel]++;
974 #endif
975 if ((rd == MIPS_CP0_TLB_INDEX)
976 && (vcpu->arch.gprs[rt] >=
977 KVM_MIPS_GUEST_TLB_SIZE)) {
978 kvm_err("Invalid TLB Index: %ld",
979 vcpu->arch.gprs[rt]);
980 er = EMULATE_FAIL;
981 break;
982 }
983 #define C0_EBASE_CORE_MASK 0xff
984 if ((rd == MIPS_CP0_PRID) && (sel == 1)) {
985 /* Preserve CORE number */
986 kvm_change_c0_guest_ebase(cop0,
987 ~(C0_EBASE_CORE_MASK),
988 vcpu->arch.gprs[rt]);
989 kvm_err("MTCz, cop0->reg[EBASE]: %#lx\n",
990 kvm_read_c0_guest_ebase(cop0));
991 } else if (rd == MIPS_CP0_TLB_HI && sel == 0) {
992 uint32_t nasid =
993 vcpu->arch.gprs[rt] & ASID_MASK;
994 if ((KSEGX(vcpu->arch.gprs[rt]) != CKSEG0) &&
995 ((kvm_read_c0_guest_entryhi(cop0) &
996 ASID_MASK) != nasid)) {
997 kvm_debug("MTCz, change ASID from %#lx to %#lx\n",
998 kvm_read_c0_guest_entryhi(cop0)
999 & ASID_MASK,
1000 vcpu->arch.gprs[rt]
1001 & ASID_MASK);
1002
1003 /* Blow away the shadow host TLBs */
1004 kvm_mips_flush_host_tlb(1);
1005 }
1006 kvm_write_c0_guest_entryhi(cop0,
1007 vcpu->arch.gprs[rt]);
1008 }
1009 /* Are we writing to COUNT */
1010 else if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
1011 kvm_mips_write_count(vcpu, vcpu->arch.gprs[rt]);
1012 goto done;
1013 } else if ((rd == MIPS_CP0_COMPARE) && (sel == 0)) {
1014 kvm_debug("[%#x] MTCz, COMPARE %#lx <- %#lx\n",
1015 pc, kvm_read_c0_guest_compare(cop0),
1016 vcpu->arch.gprs[rt]);
1017
1018 /* If we are writing to COMPARE */
1019 /* Clear pending timer interrupt, if any */
1020 kvm_mips_callbacks->dequeue_timer_int(vcpu);
1021 kvm_mips_write_compare(vcpu,
1022 vcpu->arch.gprs[rt]);
1023 } else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) {
1024 kvm_write_c0_guest_status(cop0,
1025 vcpu->arch.gprs[rt]);
1026 /*
1027 * Make sure that CU1 and NMI bits are
1028 * never set
1029 */
1030 kvm_clear_c0_guest_status(cop0,
1031 (ST0_CU1 | ST0_NMI));
1032
1033 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1034 kvm_mips_trans_mtc0(inst, opc, vcpu);
1035 #endif
1036 } else if ((rd == MIPS_CP0_CAUSE) && (sel == 0)) {
1037 uint32_t old_cause, new_cause;
1038
1039 old_cause = kvm_read_c0_guest_cause(cop0);
1040 new_cause = vcpu->arch.gprs[rt];
1041 /* Update R/W bits */
1042 kvm_change_c0_guest_cause(cop0, 0x08800300,
1043 new_cause);
1044 /* DC bit enabling/disabling timer? */
1045 if ((old_cause ^ new_cause) & CAUSEF_DC) {
1046 if (new_cause & CAUSEF_DC)
1047 kvm_mips_count_disable_cause(vcpu);
1048 else
1049 kvm_mips_count_enable_cause(vcpu);
1050 }
1051 } else {
1052 cop0->reg[rd][sel] = vcpu->arch.gprs[rt];
1053 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1054 kvm_mips_trans_mtc0(inst, opc, vcpu);
1055 #endif
1056 }
1057
1058 kvm_debug("[%#x] MTCz, cop0->reg[%d][%d]: %#lx\n", pc,
1059 rd, sel, cop0->reg[rd][sel]);
1060 break;
1061
1062 case dmtc_op:
1063 kvm_err("!!!!!!![%#lx]dmtc_op: rt: %d, rd: %d, sel: %d!!!!!!\n",
1064 vcpu->arch.pc, rt, rd, sel);
1065 er = EMULATE_FAIL;
1066 break;
1067
1068 case mfmcz_op:
1069 #ifdef KVM_MIPS_DEBUG_COP0_COUNTERS
1070 cop0->stat[MIPS_CP0_STATUS][0]++;
1071 #endif
1072 if (rt != 0) {
1073 vcpu->arch.gprs[rt] =
1074 kvm_read_c0_guest_status(cop0);
1075 }
1076 /* EI */
1077 if (inst & 0x20) {
1078 kvm_debug("[%#lx] mfmcz_op: EI\n",
1079 vcpu->arch.pc);
1080 kvm_set_c0_guest_status(cop0, ST0_IE);
1081 } else {
1082 kvm_debug("[%#lx] mfmcz_op: DI\n",
1083 vcpu->arch.pc);
1084 kvm_clear_c0_guest_status(cop0, ST0_IE);
1085 }
1086
1087 break;
1088
1089 case wrpgpr_op:
1090 {
1091 uint32_t css =
1092 cop0->reg[MIPS_CP0_STATUS][2] & 0xf;
1093 uint32_t pss =
1094 (cop0->reg[MIPS_CP0_STATUS][2] >> 6) & 0xf;
1095 /*
1096 * We don't support any shadow register sets, so
1097 * SRSCtl[PSS] == SRSCtl[CSS] = 0
1098 */
1099 if (css || pss) {
1100 er = EMULATE_FAIL;
1101 break;
1102 }
1103 kvm_debug("WRPGPR[%d][%d] = %#lx\n", pss, rd,
1104 vcpu->arch.gprs[rt]);
1105 vcpu->arch.gprs[rd] = vcpu->arch.gprs[rt];
1106 }
1107 break;
1108 default:
1109 kvm_err("[%#lx]MachEmulateCP0: unsupported COP0, copz: 0x%x\n",
1110 vcpu->arch.pc, copz);
1111 er = EMULATE_FAIL;
1112 break;
1113 }
1114 }
1115
1116 done:
1117 /* Rollback PC only if emulation was unsuccessful */
1118 if (er == EMULATE_FAIL)
1119 vcpu->arch.pc = curr_pc;
1120
1121 dont_update_pc:
1122 /*
1123 * This is for special instructions whose emulation
1124 * updates the PC, so do not overwrite the PC under
1125 * any circumstances
1126 */
1127
1128 return er;
1129 }
1130
1131 enum emulation_result kvm_mips_emulate_store(uint32_t inst, uint32_t cause,
1132 struct kvm_run *run,
1133 struct kvm_vcpu *vcpu)
1134 {
1135 enum emulation_result er = EMULATE_DO_MMIO;
1136 int32_t op, base, rt, offset;
1137 uint32_t bytes;
1138 void *data = run->mmio.data;
1139 unsigned long curr_pc;
1140
1141 /*
1142 * Update PC and hold onto current PC in case there is
1143 * an error and we want to rollback the PC
1144 */
1145 curr_pc = vcpu->arch.pc;
1146 er = update_pc(vcpu, cause);
1147 if (er == EMULATE_FAIL)
1148 return er;
1149
1150 rt = (inst >> 16) & 0x1f;
1151 base = (inst >> 21) & 0x1f;
1152 offset = inst & 0xffff;
1153 op = (inst >> 26) & 0x3f;
1154
1155 switch (op) {
1156 case sb_op:
1157 bytes = 1;
1158 if (bytes > sizeof(run->mmio.data)) {
1159 kvm_err("%s: bad MMIO length: %d\n", __func__,
1160 run->mmio.len);
1161 }
1162 run->mmio.phys_addr =
1163 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1164 host_cp0_badvaddr);
1165 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1166 er = EMULATE_FAIL;
1167 break;
1168 }
1169 run->mmio.len = bytes;
1170 run->mmio.is_write = 1;
1171 vcpu->mmio_needed = 1;
1172 vcpu->mmio_is_write = 1;
1173 *(u8 *) data = vcpu->arch.gprs[rt];
1174 kvm_debug("OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1175 vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt],
1176 *(uint8_t *) data);
1177
1178 break;
1179
1180 case sw_op:
1181 bytes = 4;
1182 if (bytes > sizeof(run->mmio.data)) {
1183 kvm_err("%s: bad MMIO length: %d\n", __func__,
1184 run->mmio.len);
1185 }
1186 run->mmio.phys_addr =
1187 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1188 host_cp0_badvaddr);
1189 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1190 er = EMULATE_FAIL;
1191 break;
1192 }
1193
1194 run->mmio.len = bytes;
1195 run->mmio.is_write = 1;
1196 vcpu->mmio_needed = 1;
1197 vcpu->mmio_is_write = 1;
1198 *(uint32_t *) data = vcpu->arch.gprs[rt];
1199
1200 kvm_debug("[%#lx] OP_SW: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1201 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1202 vcpu->arch.gprs[rt], *(uint32_t *) data);
1203 break;
1204
1205 case sh_op:
1206 bytes = 2;
1207 if (bytes > sizeof(run->mmio.data)) {
1208 kvm_err("%s: bad MMIO length: %d\n", __func__,
1209 run->mmio.len);
1210 }
1211 run->mmio.phys_addr =
1212 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1213 host_cp0_badvaddr);
1214 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1215 er = EMULATE_FAIL;
1216 break;
1217 }
1218
1219 run->mmio.len = bytes;
1220 run->mmio.is_write = 1;
1221 vcpu->mmio_needed = 1;
1222 vcpu->mmio_is_write = 1;
1223 *(uint16_t *) data = vcpu->arch.gprs[rt];
1224
1225 kvm_debug("[%#lx] OP_SH: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1226 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1227 vcpu->arch.gprs[rt], *(uint32_t *) data);
1228 break;
1229
1230 default:
1231 kvm_err("Store not yet supported");
1232 er = EMULATE_FAIL;
1233 break;
1234 }
1235
1236 /* Rollback PC if emulation was unsuccessful */
1237 if (er == EMULATE_FAIL)
1238 vcpu->arch.pc = curr_pc;
1239
1240 return er;
1241 }
1242
1243 enum emulation_result kvm_mips_emulate_load(uint32_t inst, uint32_t cause,
1244 struct kvm_run *run,
1245 struct kvm_vcpu *vcpu)
1246 {
1247 enum emulation_result er = EMULATE_DO_MMIO;
1248 int32_t op, base, rt, offset;
1249 uint32_t bytes;
1250
1251 rt = (inst >> 16) & 0x1f;
1252 base = (inst >> 21) & 0x1f;
1253 offset = inst & 0xffff;
1254 op = (inst >> 26) & 0x3f;
1255
1256 vcpu->arch.pending_load_cause = cause;
1257 vcpu->arch.io_gpr = rt;
1258
1259 switch (op) {
1260 case lw_op:
1261 bytes = 4;
1262 if (bytes > sizeof(run->mmio.data)) {
1263 kvm_err("%s: bad MMIO length: %d\n", __func__,
1264 run->mmio.len);
1265 er = EMULATE_FAIL;
1266 break;
1267 }
1268 run->mmio.phys_addr =
1269 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1270 host_cp0_badvaddr);
1271 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1272 er = EMULATE_FAIL;
1273 break;
1274 }
1275
1276 run->mmio.len = bytes;
1277 run->mmio.is_write = 0;
1278 vcpu->mmio_needed = 1;
1279 vcpu->mmio_is_write = 0;
1280 break;
1281
1282 case lh_op:
1283 case lhu_op:
1284 bytes = 2;
1285 if (bytes > sizeof(run->mmio.data)) {
1286 kvm_err("%s: bad MMIO length: %d\n", __func__,
1287 run->mmio.len);
1288 er = EMULATE_FAIL;
1289 break;
1290 }
1291 run->mmio.phys_addr =
1292 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1293 host_cp0_badvaddr);
1294 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1295 er = EMULATE_FAIL;
1296 break;
1297 }
1298
1299 run->mmio.len = bytes;
1300 run->mmio.is_write = 0;
1301 vcpu->mmio_needed = 1;
1302 vcpu->mmio_is_write = 0;
1303
1304 if (op == lh_op)
1305 vcpu->mmio_needed = 2;
1306 else
1307 vcpu->mmio_needed = 1;
1308
1309 break;
1310
1311 case lbu_op:
1312 case lb_op:
1313 bytes = 1;
1314 if (bytes > sizeof(run->mmio.data)) {
1315 kvm_err("%s: bad MMIO length: %d\n", __func__,
1316 run->mmio.len);
1317 er = EMULATE_FAIL;
1318 break;
1319 }
1320 run->mmio.phys_addr =
1321 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1322 host_cp0_badvaddr);
1323 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1324 er = EMULATE_FAIL;
1325 break;
1326 }
1327
1328 run->mmio.len = bytes;
1329 run->mmio.is_write = 0;
1330 vcpu->mmio_is_write = 0;
1331
1332 if (op == lb_op)
1333 vcpu->mmio_needed = 2;
1334 else
1335 vcpu->mmio_needed = 1;
1336
1337 break;
1338
1339 default:
1340 kvm_err("Load not yet supported");
1341 er = EMULATE_FAIL;
1342 break;
1343 }
1344
1345 return er;
1346 }
1347
1348 int kvm_mips_sync_icache(unsigned long va, struct kvm_vcpu *vcpu)
1349 {
1350 unsigned long offset = (va & ~PAGE_MASK);
1351 struct kvm *kvm = vcpu->kvm;
1352 unsigned long pa;
1353 gfn_t gfn;
1354 pfn_t pfn;
1355
1356 gfn = va >> PAGE_SHIFT;
1357
1358 if (gfn >= kvm->arch.guest_pmap_npages) {
1359 kvm_err("%s: Invalid gfn: %#llx\n", __func__, gfn);
1360 kvm_mips_dump_host_tlbs();
1361 kvm_arch_vcpu_dump_regs(vcpu);
1362 return -1;
1363 }
1364 pfn = kvm->arch.guest_pmap[gfn];
1365 pa = (pfn << PAGE_SHIFT) | offset;
1366
1367 kvm_debug("%s: va: %#lx, unmapped: %#x\n", __func__, va,
1368 CKSEG0ADDR(pa));
1369
1370 local_flush_icache_range(CKSEG0ADDR(pa), 32);
1371 return 0;
1372 }
1373
1374 #define MIPS_CACHE_OP_INDEX_INV 0x0
1375 #define MIPS_CACHE_OP_INDEX_LD_TAG 0x1
1376 #define MIPS_CACHE_OP_INDEX_ST_TAG 0x2
1377 #define MIPS_CACHE_OP_IMP 0x3
1378 #define MIPS_CACHE_OP_HIT_INV 0x4
1379 #define MIPS_CACHE_OP_FILL_WB_INV 0x5
1380 #define MIPS_CACHE_OP_HIT_HB 0x6
1381 #define MIPS_CACHE_OP_FETCH_LOCK 0x7
1382
1383 #define MIPS_CACHE_ICACHE 0x0
1384 #define MIPS_CACHE_DCACHE 0x1
1385 #define MIPS_CACHE_SEC 0x3
1386
1387 enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc,
1388 uint32_t cause,
1389 struct kvm_run *run,
1390 struct kvm_vcpu *vcpu)
1391 {
1392 struct mips_coproc *cop0 = vcpu->arch.cop0;
1393 enum emulation_result er = EMULATE_DONE;
1394 int32_t offset, cache, op_inst, op, base;
1395 struct kvm_vcpu_arch *arch = &vcpu->arch;
1396 unsigned long va;
1397 unsigned long curr_pc;
1398
1399 /*
1400 * Update PC and hold onto current PC in case there is
1401 * an error and we want to rollback the PC
1402 */
1403 curr_pc = vcpu->arch.pc;
1404 er = update_pc(vcpu, cause);
1405 if (er == EMULATE_FAIL)
1406 return er;
1407
1408 base = (inst >> 21) & 0x1f;
1409 op_inst = (inst >> 16) & 0x1f;
1410 offset = inst & 0xffff;
1411 cache = (inst >> 16) & 0x3;
1412 op = (inst >> 18) & 0x7;
1413
1414 va = arch->gprs[base] + offset;
1415
1416 kvm_debug("CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1417 cache, op, base, arch->gprs[base], offset);
1418
1419 /*
1420 * Treat INDEX_INV as a nop, basically issued by Linux on startup to
1421 * invalidate the caches entirely by stepping through all the
1422 * ways/indexes
1423 */
1424 if (op == MIPS_CACHE_OP_INDEX_INV) {
1425 kvm_debug("@ %#lx/%#lx CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1426 vcpu->arch.pc, vcpu->arch.gprs[31], cache, op, base,
1427 arch->gprs[base], offset);
1428
1429 if (cache == MIPS_CACHE_DCACHE)
1430 r4k_blast_dcache();
1431 else if (cache == MIPS_CACHE_ICACHE)
1432 r4k_blast_icache();
1433 else {
1434 kvm_err("%s: unsupported CACHE INDEX operation\n",
1435 __func__);
1436 return EMULATE_FAIL;
1437 }
1438
1439 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1440 kvm_mips_trans_cache_index(inst, opc, vcpu);
1441 #endif
1442 goto done;
1443 }
1444
1445 preempt_disable();
1446 if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
1447 if (kvm_mips_host_tlb_lookup(vcpu, va) < 0)
1448 kvm_mips_handle_kseg0_tlb_fault(va, vcpu);
1449 } else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) ||
1450 KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
1451 int index;
1452
1453 /* If an entry already exists then skip */
1454 if (kvm_mips_host_tlb_lookup(vcpu, va) >= 0)
1455 goto skip_fault;
1456
1457 /*
1458 * If address not in the guest TLB, then give the guest a fault,
1459 * the resulting handler will do the right thing
1460 */
1461 index = kvm_mips_guest_tlb_lookup(vcpu, (va & VPN2_MASK) |
1462 (kvm_read_c0_guest_entryhi
1463 (cop0) & ASID_MASK));
1464
1465 if (index < 0) {
1466 vcpu->arch.host_cp0_entryhi = (va & VPN2_MASK);
1467 vcpu->arch.host_cp0_badvaddr = va;
1468 er = kvm_mips_emulate_tlbmiss_ld(cause, NULL, run,
1469 vcpu);
1470 preempt_enable();
1471 goto dont_update_pc;
1472 } else {
1473 struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
1474 /*
1475 * Check if the entry is valid, if not then setup a TLB
1476 * invalid exception to the guest
1477 */
1478 if (!TLB_IS_VALID(*tlb, va)) {
1479 er = kvm_mips_emulate_tlbinv_ld(cause, NULL,
1480 run, vcpu);
1481 preempt_enable();
1482 goto dont_update_pc;
1483 } else {
1484 /*
1485 * We fault an entry from the guest tlb to the
1486 * shadow host TLB
1487 */
1488 kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
1489 NULL,
1490 NULL);
1491 }
1492 }
1493 } else {
1494 kvm_err("INVALID CACHE INDEX/ADDRESS (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1495 cache, op, base, arch->gprs[base], offset);
1496 er = EMULATE_FAIL;
1497 preempt_enable();
1498 goto dont_update_pc;
1499
1500 }
1501
1502 skip_fault:
1503 /* XXXKYMA: Only a subset of cache ops are supported, used by Linux */
1504 if (cache == MIPS_CACHE_DCACHE
1505 && (op == MIPS_CACHE_OP_FILL_WB_INV
1506 || op == MIPS_CACHE_OP_HIT_INV)) {
1507 flush_dcache_line(va);
1508
1509 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1510 /*
1511 * Replace the CACHE instruction, with a SYNCI, not the same,
1512 * but avoids a trap
1513 */
1514 kvm_mips_trans_cache_va(inst, opc, vcpu);
1515 #endif
1516 } else if (op == MIPS_CACHE_OP_HIT_INV && cache == MIPS_CACHE_ICACHE) {
1517 flush_dcache_line(va);
1518 flush_icache_line(va);
1519
1520 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1521 /* Replace the CACHE instruction, with a SYNCI */
1522 kvm_mips_trans_cache_va(inst, opc, vcpu);
1523 #endif
1524 } else {
1525 kvm_err("NO-OP CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1526 cache, op, base, arch->gprs[base], offset);
1527 er = EMULATE_FAIL;
1528 preempt_enable();
1529 goto dont_update_pc;
1530 }
1531
1532 preempt_enable();
1533
1534 dont_update_pc:
1535 /* Rollback PC */
1536 vcpu->arch.pc = curr_pc;
1537 done:
1538 return er;
1539 }
1540
1541 enum emulation_result kvm_mips_emulate_inst(unsigned long cause, uint32_t *opc,
1542 struct kvm_run *run,
1543 struct kvm_vcpu *vcpu)
1544 {
1545 enum emulation_result er = EMULATE_DONE;
1546 uint32_t inst;
1547
1548 /* Fetch the instruction. */
1549 if (cause & CAUSEF_BD)
1550 opc += 1;
1551
1552 inst = kvm_get_inst(opc, vcpu);
1553
1554 switch (((union mips_instruction)inst).r_format.opcode) {
1555 case cop0_op:
1556 er = kvm_mips_emulate_CP0(inst, opc, cause, run, vcpu);
1557 break;
1558 case sb_op:
1559 case sh_op:
1560 case sw_op:
1561 er = kvm_mips_emulate_store(inst, cause, run, vcpu);
1562 break;
1563 case lb_op:
1564 case lbu_op:
1565 case lhu_op:
1566 case lh_op:
1567 case lw_op:
1568 er = kvm_mips_emulate_load(inst, cause, run, vcpu);
1569 break;
1570
1571 case cache_op:
1572 ++vcpu->stat.cache_exits;
1573 trace_kvm_exit(vcpu, CACHE_EXITS);
1574 er = kvm_mips_emulate_cache(inst, opc, cause, run, vcpu);
1575 break;
1576
1577 default:
1578 kvm_err("Instruction emulation not supported (%p/%#x)\n", opc,
1579 inst);
1580 kvm_arch_vcpu_dump_regs(vcpu);
1581 er = EMULATE_FAIL;
1582 break;
1583 }
1584
1585 return er;
1586 }
1587
1588 enum emulation_result kvm_mips_emulate_syscall(unsigned long cause,
1589 uint32_t *opc,
1590 struct kvm_run *run,
1591 struct kvm_vcpu *vcpu)
1592 {
1593 struct mips_coproc *cop0 = vcpu->arch.cop0;
1594 struct kvm_vcpu_arch *arch = &vcpu->arch;
1595 enum emulation_result er = EMULATE_DONE;
1596
1597 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1598 /* save old pc */
1599 kvm_write_c0_guest_epc(cop0, arch->pc);
1600 kvm_set_c0_guest_status(cop0, ST0_EXL);
1601
1602 if (cause & CAUSEF_BD)
1603 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1604 else
1605 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1606
1607 kvm_debug("Delivering SYSCALL @ pc %#lx\n", arch->pc);
1608
1609 kvm_change_c0_guest_cause(cop0, (0xff),
1610 (T_SYSCALL << CAUSEB_EXCCODE));
1611
1612 /* Set PC to the exception entry point */
1613 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1614
1615 } else {
1616 kvm_err("Trying to deliver SYSCALL when EXL is already set\n");
1617 er = EMULATE_FAIL;
1618 }
1619
1620 return er;
1621 }
1622
1623 enum emulation_result kvm_mips_emulate_tlbmiss_ld(unsigned long cause,
1624 uint32_t *opc,
1625 struct kvm_run *run,
1626 struct kvm_vcpu *vcpu)
1627 {
1628 struct mips_coproc *cop0 = vcpu->arch.cop0;
1629 struct kvm_vcpu_arch *arch = &vcpu->arch;
1630 unsigned long entryhi = (vcpu->arch. host_cp0_badvaddr & VPN2_MASK) |
1631 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1632
1633 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1634 /* save old pc */
1635 kvm_write_c0_guest_epc(cop0, arch->pc);
1636 kvm_set_c0_guest_status(cop0, ST0_EXL);
1637
1638 if (cause & CAUSEF_BD)
1639 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1640 else
1641 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1642
1643 kvm_debug("[EXL == 0] delivering TLB MISS @ pc %#lx\n",
1644 arch->pc);
1645
1646 /* set pc to the exception entry point */
1647 arch->pc = KVM_GUEST_KSEG0 + 0x0;
1648
1649 } else {
1650 kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1651 arch->pc);
1652
1653 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1654 }
1655
1656 kvm_change_c0_guest_cause(cop0, (0xff),
1657 (T_TLB_LD_MISS << CAUSEB_EXCCODE));
1658
1659 /* setup badvaddr, context and entryhi registers for the guest */
1660 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1661 /* XXXKYMA: is the context register used by linux??? */
1662 kvm_write_c0_guest_entryhi(cop0, entryhi);
1663 /* Blow away the shadow host TLBs */
1664 kvm_mips_flush_host_tlb(1);
1665
1666 return EMULATE_DONE;
1667 }
1668
1669 enum emulation_result kvm_mips_emulate_tlbinv_ld(unsigned long cause,
1670 uint32_t *opc,
1671 struct kvm_run *run,
1672 struct kvm_vcpu *vcpu)
1673 {
1674 struct mips_coproc *cop0 = vcpu->arch.cop0;
1675 struct kvm_vcpu_arch *arch = &vcpu->arch;
1676 unsigned long entryhi =
1677 (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1678 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1679
1680 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1681 /* save old pc */
1682 kvm_write_c0_guest_epc(cop0, arch->pc);
1683 kvm_set_c0_guest_status(cop0, ST0_EXL);
1684
1685 if (cause & CAUSEF_BD)
1686 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1687 else
1688 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1689
1690 kvm_debug("[EXL == 0] delivering TLB INV @ pc %#lx\n",
1691 arch->pc);
1692
1693 /* set pc to the exception entry point */
1694 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1695
1696 } else {
1697 kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1698 arch->pc);
1699 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1700 }
1701
1702 kvm_change_c0_guest_cause(cop0, (0xff),
1703 (T_TLB_LD_MISS << CAUSEB_EXCCODE));
1704
1705 /* setup badvaddr, context and entryhi registers for the guest */
1706 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1707 /* XXXKYMA: is the context register used by linux??? */
1708 kvm_write_c0_guest_entryhi(cop0, entryhi);
1709 /* Blow away the shadow host TLBs */
1710 kvm_mips_flush_host_tlb(1);
1711
1712 return EMULATE_DONE;
1713 }
1714
1715 enum emulation_result kvm_mips_emulate_tlbmiss_st(unsigned long cause,
1716 uint32_t *opc,
1717 struct kvm_run *run,
1718 struct kvm_vcpu *vcpu)
1719 {
1720 struct mips_coproc *cop0 = vcpu->arch.cop0;
1721 struct kvm_vcpu_arch *arch = &vcpu->arch;
1722 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1723 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1724
1725 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1726 /* save old pc */
1727 kvm_write_c0_guest_epc(cop0, arch->pc);
1728 kvm_set_c0_guest_status(cop0, ST0_EXL);
1729
1730 if (cause & CAUSEF_BD)
1731 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1732 else
1733 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1734
1735 kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
1736 arch->pc);
1737
1738 /* Set PC to the exception entry point */
1739 arch->pc = KVM_GUEST_KSEG0 + 0x0;
1740 } else {
1741 kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
1742 arch->pc);
1743 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1744 }
1745
1746 kvm_change_c0_guest_cause(cop0, (0xff),
1747 (T_TLB_ST_MISS << CAUSEB_EXCCODE));
1748
1749 /* setup badvaddr, context and entryhi registers for the guest */
1750 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1751 /* XXXKYMA: is the context register used by linux??? */
1752 kvm_write_c0_guest_entryhi(cop0, entryhi);
1753 /* Blow away the shadow host TLBs */
1754 kvm_mips_flush_host_tlb(1);
1755
1756 return EMULATE_DONE;
1757 }
1758
1759 enum emulation_result kvm_mips_emulate_tlbinv_st(unsigned long cause,
1760 uint32_t *opc,
1761 struct kvm_run *run,
1762 struct kvm_vcpu *vcpu)
1763 {
1764 struct mips_coproc *cop0 = vcpu->arch.cop0;
1765 struct kvm_vcpu_arch *arch = &vcpu->arch;
1766 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1767 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1768
1769 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1770 /* save old pc */
1771 kvm_write_c0_guest_epc(cop0, arch->pc);
1772 kvm_set_c0_guest_status(cop0, ST0_EXL);
1773
1774 if (cause & CAUSEF_BD)
1775 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1776 else
1777 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1778
1779 kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
1780 arch->pc);
1781
1782 /* Set PC to the exception entry point */
1783 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1784 } else {
1785 kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
1786 arch->pc);
1787 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1788 }
1789
1790 kvm_change_c0_guest_cause(cop0, (0xff),
1791 (T_TLB_ST_MISS << CAUSEB_EXCCODE));
1792
1793 /* setup badvaddr, context and entryhi registers for the guest */
1794 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1795 /* XXXKYMA: is the context register used by linux??? */
1796 kvm_write_c0_guest_entryhi(cop0, entryhi);
1797 /* Blow away the shadow host TLBs */
1798 kvm_mips_flush_host_tlb(1);
1799
1800 return EMULATE_DONE;
1801 }
1802
1803 /* TLBMOD: store into address matching TLB with Dirty bit off */
1804 enum emulation_result kvm_mips_handle_tlbmod(unsigned long cause, uint32_t *opc,
1805 struct kvm_run *run,
1806 struct kvm_vcpu *vcpu)
1807 {
1808 enum emulation_result er = EMULATE_DONE;
1809 #ifdef DEBUG
1810 struct mips_coproc *cop0 = vcpu->arch.cop0;
1811 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1812 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1813 int index;
1814
1815 /* If address not in the guest TLB, then we are in trouble */
1816 index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
1817 if (index < 0) {
1818 /* XXXKYMA Invalidate and retry */
1819 kvm_mips_host_tlb_inv(vcpu, vcpu->arch.host_cp0_badvaddr);
1820 kvm_err("%s: host got TLBMOD for %#lx but entry not present in Guest TLB\n",
1821 __func__, entryhi);
1822 kvm_mips_dump_guest_tlbs(vcpu);
1823 kvm_mips_dump_host_tlbs();
1824 return EMULATE_FAIL;
1825 }
1826 #endif
1827
1828 er = kvm_mips_emulate_tlbmod(cause, opc, run, vcpu);
1829 return er;
1830 }
1831
1832 enum emulation_result kvm_mips_emulate_tlbmod(unsigned long cause,
1833 uint32_t *opc,
1834 struct kvm_run *run,
1835 struct kvm_vcpu *vcpu)
1836 {
1837 struct mips_coproc *cop0 = vcpu->arch.cop0;
1838 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1839 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1840 struct kvm_vcpu_arch *arch = &vcpu->arch;
1841
1842 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1843 /* save old pc */
1844 kvm_write_c0_guest_epc(cop0, arch->pc);
1845 kvm_set_c0_guest_status(cop0, ST0_EXL);
1846
1847 if (cause & CAUSEF_BD)
1848 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1849 else
1850 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1851
1852 kvm_debug("[EXL == 0] Delivering TLB MOD @ pc %#lx\n",
1853 arch->pc);
1854
1855 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1856 } else {
1857 kvm_debug("[EXL == 1] Delivering TLB MOD @ pc %#lx\n",
1858 arch->pc);
1859 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1860 }
1861
1862 kvm_change_c0_guest_cause(cop0, (0xff), (T_TLB_MOD << CAUSEB_EXCCODE));
1863
1864 /* setup badvaddr, context and entryhi registers for the guest */
1865 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1866 /* XXXKYMA: is the context register used by linux??? */
1867 kvm_write_c0_guest_entryhi(cop0, entryhi);
1868 /* Blow away the shadow host TLBs */
1869 kvm_mips_flush_host_tlb(1);
1870
1871 return EMULATE_DONE;
1872 }
1873
1874 enum emulation_result kvm_mips_emulate_fpu_exc(unsigned long cause,
1875 uint32_t *opc,
1876 struct kvm_run *run,
1877 struct kvm_vcpu *vcpu)
1878 {
1879 struct mips_coproc *cop0 = vcpu->arch.cop0;
1880 struct kvm_vcpu_arch *arch = &vcpu->arch;
1881
1882 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1883 /* save old pc */
1884 kvm_write_c0_guest_epc(cop0, arch->pc);
1885 kvm_set_c0_guest_status(cop0, ST0_EXL);
1886
1887 if (cause & CAUSEF_BD)
1888 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1889 else
1890 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1891
1892 }
1893
1894 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1895
1896 kvm_change_c0_guest_cause(cop0, (0xff),
1897 (T_COP_UNUSABLE << CAUSEB_EXCCODE));
1898 kvm_change_c0_guest_cause(cop0, (CAUSEF_CE), (0x1 << CAUSEB_CE));
1899
1900 return EMULATE_DONE;
1901 }
1902
1903 enum emulation_result kvm_mips_emulate_ri_exc(unsigned long cause,
1904 uint32_t *opc,
1905 struct kvm_run *run,
1906 struct kvm_vcpu *vcpu)
1907 {
1908 struct mips_coproc *cop0 = vcpu->arch.cop0;
1909 struct kvm_vcpu_arch *arch = &vcpu->arch;
1910 enum emulation_result er = EMULATE_DONE;
1911
1912 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1913 /* save old pc */
1914 kvm_write_c0_guest_epc(cop0, arch->pc);
1915 kvm_set_c0_guest_status(cop0, ST0_EXL);
1916
1917 if (cause & CAUSEF_BD)
1918 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1919 else
1920 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1921
1922 kvm_debug("Delivering RI @ pc %#lx\n", arch->pc);
1923
1924 kvm_change_c0_guest_cause(cop0, (0xff),
1925 (T_RES_INST << CAUSEB_EXCCODE));
1926
1927 /* Set PC to the exception entry point */
1928 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1929
1930 } else {
1931 kvm_err("Trying to deliver RI when EXL is already set\n");
1932 er = EMULATE_FAIL;
1933 }
1934
1935 return er;
1936 }
1937
1938 enum emulation_result kvm_mips_emulate_bp_exc(unsigned long cause,
1939 uint32_t *opc,
1940 struct kvm_run *run,
1941 struct kvm_vcpu *vcpu)
1942 {
1943 struct mips_coproc *cop0 = vcpu->arch.cop0;
1944 struct kvm_vcpu_arch *arch = &vcpu->arch;
1945 enum emulation_result er = EMULATE_DONE;
1946
1947 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1948 /* save old pc */
1949 kvm_write_c0_guest_epc(cop0, arch->pc);
1950 kvm_set_c0_guest_status(cop0, ST0_EXL);
1951
1952 if (cause & CAUSEF_BD)
1953 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1954 else
1955 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1956
1957 kvm_debug("Delivering BP @ pc %#lx\n", arch->pc);
1958
1959 kvm_change_c0_guest_cause(cop0, (0xff),
1960 (T_BREAK << CAUSEB_EXCCODE));
1961
1962 /* Set PC to the exception entry point */
1963 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1964
1965 } else {
1966 kvm_err("Trying to deliver BP when EXL is already set\n");
1967 er = EMULATE_FAIL;
1968 }
1969
1970 return er;
1971 }
1972
1973 /* ll/sc, rdhwr, sync emulation */
1974
1975 #define OPCODE 0xfc000000
1976 #define BASE 0x03e00000
1977 #define RT 0x001f0000
1978 #define OFFSET 0x0000ffff
1979 #define LL 0xc0000000
1980 #define SC 0xe0000000
1981 #define SPEC0 0x00000000
1982 #define SPEC3 0x7c000000
1983 #define RD 0x0000f800
1984 #define FUNC 0x0000003f
1985 #define SYNC 0x0000000f
1986 #define RDHWR 0x0000003b
1987
1988 enum emulation_result kvm_mips_handle_ri(unsigned long cause, uint32_t *opc,
1989 struct kvm_run *run,
1990 struct kvm_vcpu *vcpu)
1991 {
1992 struct mips_coproc *cop0 = vcpu->arch.cop0;
1993 struct kvm_vcpu_arch *arch = &vcpu->arch;
1994 enum emulation_result er = EMULATE_DONE;
1995 unsigned long curr_pc;
1996 uint32_t inst;
1997
1998 /*
1999 * Update PC and hold onto current PC in case there is
2000 * an error and we want to rollback the PC
2001 */
2002 curr_pc = vcpu->arch.pc;
2003 er = update_pc(vcpu, cause);
2004 if (er == EMULATE_FAIL)
2005 return er;
2006
2007 /* Fetch the instruction. */
2008 if (cause & CAUSEF_BD)
2009 opc += 1;
2010
2011 inst = kvm_get_inst(opc, vcpu);
2012
2013 if (inst == KVM_INVALID_INST) {
2014 kvm_err("%s: Cannot get inst @ %p\n", __func__, opc);
2015 return EMULATE_FAIL;
2016 }
2017
2018 if ((inst & OPCODE) == SPEC3 && (inst & FUNC) == RDHWR) {
2019 int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
2020 int rd = (inst & RD) >> 11;
2021 int rt = (inst & RT) >> 16;
2022 /* If usermode, check RDHWR rd is allowed by guest HWREna */
2023 if (usermode && !(kvm_read_c0_guest_hwrena(cop0) & BIT(rd))) {
2024 kvm_debug("RDHWR %#x disallowed by HWREna @ %p\n",
2025 rd, opc);
2026 goto emulate_ri;
2027 }
2028 switch (rd) {
2029 case 0: /* CPU number */
2030 arch->gprs[rt] = 0;
2031 break;
2032 case 1: /* SYNCI length */
2033 arch->gprs[rt] = min(current_cpu_data.dcache.linesz,
2034 current_cpu_data.icache.linesz);
2035 break;
2036 case 2: /* Read count register */
2037 arch->gprs[rt] = kvm_mips_read_count(vcpu);
2038 break;
2039 case 3: /* Count register resolution */
2040 switch (current_cpu_data.cputype) {
2041 case CPU_20KC:
2042 case CPU_25KF:
2043 arch->gprs[rt] = 1;
2044 break;
2045 default:
2046 arch->gprs[rt] = 2;
2047 }
2048 break;
2049 case 29:
2050 arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0);
2051 break;
2052
2053 default:
2054 kvm_debug("RDHWR %#x not supported @ %p\n", rd, opc);
2055 goto emulate_ri;
2056 }
2057 } else {
2058 kvm_debug("Emulate RI not supported @ %p: %#x\n", opc, inst);
2059 goto emulate_ri;
2060 }
2061
2062 return EMULATE_DONE;
2063
2064 emulate_ri:
2065 /*
2066 * Rollback PC (if in branch delay slot then the PC already points to
2067 * branch target), and pass the RI exception to the guest OS.
2068 */
2069 vcpu->arch.pc = curr_pc;
2070 return kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
2071 }
2072
2073 enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu,
2074 struct kvm_run *run)
2075 {
2076 unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
2077 enum emulation_result er = EMULATE_DONE;
2078 unsigned long curr_pc;
2079
2080 if (run->mmio.len > sizeof(*gpr)) {
2081 kvm_err("Bad MMIO length: %d", run->mmio.len);
2082 er = EMULATE_FAIL;
2083 goto done;
2084 }
2085
2086 /*
2087 * Update PC and hold onto current PC in case there is
2088 * an error and we want to rollback the PC
2089 */
2090 curr_pc = vcpu->arch.pc;
2091 er = update_pc(vcpu, vcpu->arch.pending_load_cause);
2092 if (er == EMULATE_FAIL)
2093 return er;
2094
2095 switch (run->mmio.len) {
2096 case 4:
2097 *gpr = *(int32_t *) run->mmio.data;
2098 break;
2099
2100 case 2:
2101 if (vcpu->mmio_needed == 2)
2102 *gpr = *(int16_t *) run->mmio.data;
2103 else
2104 *gpr = *(int16_t *) run->mmio.data;
2105
2106 break;
2107 case 1:
2108 if (vcpu->mmio_needed == 2)
2109 *gpr = *(int8_t *) run->mmio.data;
2110 else
2111 *gpr = *(u8 *) run->mmio.data;
2112 break;
2113 }
2114
2115 if (vcpu->arch.pending_load_cause & CAUSEF_BD)
2116 kvm_debug("[%#lx] Completing %d byte BD Load to gpr %d (0x%08lx) type %d\n",
2117 vcpu->arch.pc, run->mmio.len, vcpu->arch.io_gpr, *gpr,
2118 vcpu->mmio_needed);
2119
2120 done:
2121 return er;
2122 }
2123
2124 static enum emulation_result kvm_mips_emulate_exc(unsigned long cause,
2125 uint32_t *opc,
2126 struct kvm_run *run,
2127 struct kvm_vcpu *vcpu)
2128 {
2129 uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2130 struct mips_coproc *cop0 = vcpu->arch.cop0;
2131 struct kvm_vcpu_arch *arch = &vcpu->arch;
2132 enum emulation_result er = EMULATE_DONE;
2133
2134 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2135 /* save old pc */
2136 kvm_write_c0_guest_epc(cop0, arch->pc);
2137 kvm_set_c0_guest_status(cop0, ST0_EXL);
2138
2139 if (cause & CAUSEF_BD)
2140 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2141 else
2142 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2143
2144 kvm_change_c0_guest_cause(cop0, (0xff),
2145 (exccode << CAUSEB_EXCCODE));
2146
2147 /* Set PC to the exception entry point */
2148 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2149 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2150
2151 kvm_debug("Delivering EXC %d @ pc %#lx, badVaddr: %#lx\n",
2152 exccode, kvm_read_c0_guest_epc(cop0),
2153 kvm_read_c0_guest_badvaddr(cop0));
2154 } else {
2155 kvm_err("Trying to deliver EXC when EXL is already set\n");
2156 er = EMULATE_FAIL;
2157 }
2158
2159 return er;
2160 }
2161
2162 enum emulation_result kvm_mips_check_privilege(unsigned long cause,
2163 uint32_t *opc,
2164 struct kvm_run *run,
2165 struct kvm_vcpu *vcpu)
2166 {
2167 enum emulation_result er = EMULATE_DONE;
2168 uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2169 unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
2170
2171 int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
2172
2173 if (usermode) {
2174 switch (exccode) {
2175 case T_INT:
2176 case T_SYSCALL:
2177 case T_BREAK:
2178 case T_RES_INST:
2179 break;
2180
2181 case T_COP_UNUSABLE:
2182 if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 0)
2183 er = EMULATE_PRIV_FAIL;
2184 break;
2185
2186 case T_TLB_MOD:
2187 break;
2188
2189 case T_TLB_LD_MISS:
2190 /*
2191 * We we are accessing Guest kernel space, then send an
2192 * address error exception to the guest
2193 */
2194 if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
2195 kvm_debug("%s: LD MISS @ %#lx\n", __func__,
2196 badvaddr);
2197 cause &= ~0xff;
2198 cause |= (T_ADDR_ERR_LD << CAUSEB_EXCCODE);
2199 er = EMULATE_PRIV_FAIL;
2200 }
2201 break;
2202
2203 case T_TLB_ST_MISS:
2204 /*
2205 * We we are accessing Guest kernel space, then send an
2206 * address error exception to the guest
2207 */
2208 if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
2209 kvm_debug("%s: ST MISS @ %#lx\n", __func__,
2210 badvaddr);
2211 cause &= ~0xff;
2212 cause |= (T_ADDR_ERR_ST << CAUSEB_EXCCODE);
2213 er = EMULATE_PRIV_FAIL;
2214 }
2215 break;
2216
2217 case T_ADDR_ERR_ST:
2218 kvm_debug("%s: address error ST @ %#lx\n", __func__,
2219 badvaddr);
2220 if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
2221 cause &= ~0xff;
2222 cause |= (T_TLB_ST_MISS << CAUSEB_EXCCODE);
2223 }
2224 er = EMULATE_PRIV_FAIL;
2225 break;
2226 case T_ADDR_ERR_LD:
2227 kvm_debug("%s: address error LD @ %#lx\n", __func__,
2228 badvaddr);
2229 if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
2230 cause &= ~0xff;
2231 cause |= (T_TLB_LD_MISS << CAUSEB_EXCCODE);
2232 }
2233 er = EMULATE_PRIV_FAIL;
2234 break;
2235 default:
2236 er = EMULATE_PRIV_FAIL;
2237 break;
2238 }
2239 }
2240
2241 if (er == EMULATE_PRIV_FAIL)
2242 kvm_mips_emulate_exc(cause, opc, run, vcpu);
2243
2244 return er;
2245 }
2246
2247 /*
2248 * User Address (UA) fault, this could happen if
2249 * (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this
2250 * case we pass on the fault to the guest kernel and let it handle it.
2251 * (2) TLB entry is present in the Guest TLB but not in the shadow, in this
2252 * case we inject the TLB from the Guest TLB into the shadow host TLB
2253 */
2254 enum emulation_result kvm_mips_handle_tlbmiss(unsigned long cause,
2255 uint32_t *opc,
2256 struct kvm_run *run,
2257 struct kvm_vcpu *vcpu)
2258 {
2259 enum emulation_result er = EMULATE_DONE;
2260 uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2261 unsigned long va = vcpu->arch.host_cp0_badvaddr;
2262 int index;
2263
2264 kvm_debug("kvm_mips_handle_tlbmiss: badvaddr: %#lx, entryhi: %#lx\n",
2265 vcpu->arch.host_cp0_badvaddr, vcpu->arch.host_cp0_entryhi);
2266
2267 /*
2268 * KVM would not have got the exception if this entry was valid in the
2269 * shadow host TLB. Check the Guest TLB, if the entry is not there then
2270 * send the guest an exception. The guest exc handler should then inject
2271 * an entry into the guest TLB.
2272 */
2273 index = kvm_mips_guest_tlb_lookup(vcpu,
2274 (va & VPN2_MASK) |
2275 (kvm_read_c0_guest_entryhi
2276 (vcpu->arch.cop0) & ASID_MASK));
2277 if (index < 0) {
2278 if (exccode == T_TLB_LD_MISS) {
2279 er = kvm_mips_emulate_tlbmiss_ld(cause, opc, run, vcpu);
2280 } else if (exccode == T_TLB_ST_MISS) {
2281 er = kvm_mips_emulate_tlbmiss_st(cause, opc, run, vcpu);
2282 } else {
2283 kvm_err("%s: invalid exc code: %d\n", __func__,
2284 exccode);
2285 er = EMULATE_FAIL;
2286 }
2287 } else {
2288 struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
2289
2290 /*
2291 * Check if the entry is valid, if not then setup a TLB invalid
2292 * exception to the guest
2293 */
2294 if (!TLB_IS_VALID(*tlb, va)) {
2295 if (exccode == T_TLB_LD_MISS) {
2296 er = kvm_mips_emulate_tlbinv_ld(cause, opc, run,
2297 vcpu);
2298 } else if (exccode == T_TLB_ST_MISS) {
2299 er = kvm_mips_emulate_tlbinv_st(cause, opc, run,
2300 vcpu);
2301 } else {
2302 kvm_err("%s: invalid exc code: %d\n", __func__,
2303 exccode);
2304 er = EMULATE_FAIL;
2305 }
2306 } else {
2307 kvm_debug("Injecting hi: %#lx, lo0: %#lx, lo1: %#lx into shadow host TLB\n",
2308 tlb->tlb_hi, tlb->tlb_lo0, tlb->tlb_lo1);
2309 /*
2310 * OK we have a Guest TLB entry, now inject it into the
2311 * shadow host TLB
2312 */
2313 kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, NULL,
2314 NULL);
2315 }
2316 }
2317
2318 return er;
2319 }
Linux with added FPC-III support