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Merge tag 'drm-intel-fixes-2015-07-15' into drm-intel-next-queued
[mirror_ubuntu-artful-kernel.git] / arch / mips / kvm / emulate.c
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 /**
888 * kvm_mips_config1_wrmask() - Find mask of writable bits in guest Config1
889 * @vcpu: Virtual CPU.
890 *
891 * Finds the mask of bits which are writable in the guest's Config1 CP0
892 * register, by userland (currently read-only to the guest).
893 */
894 unsigned int kvm_mips_config1_wrmask(struct kvm_vcpu *vcpu)
895 {
896 unsigned int mask = 0;
897
898 /* Permit FPU to be present if FPU is supported */
899 if (kvm_mips_guest_can_have_fpu(&vcpu->arch))
900 mask |= MIPS_CONF1_FP;
901
902 return mask;
903 }
904
905 /**
906 * kvm_mips_config3_wrmask() - Find mask of writable bits in guest Config3
907 * @vcpu: Virtual CPU.
908 *
909 * Finds the mask of bits which are writable in the guest's Config3 CP0
910 * register, by userland (currently read-only to the guest).
911 */
912 unsigned int kvm_mips_config3_wrmask(struct kvm_vcpu *vcpu)
913 {
914 /* Config4 is optional */
915 unsigned int mask = MIPS_CONF_M;
916
917 /* Permit MSA to be present if MSA is supported */
918 if (kvm_mips_guest_can_have_msa(&vcpu->arch))
919 mask |= MIPS_CONF3_MSA;
920
921 return mask;
922 }
923
924 /**
925 * kvm_mips_config4_wrmask() - Find mask of writable bits in guest Config4
926 * @vcpu: Virtual CPU.
927 *
928 * Finds the mask of bits which are writable in the guest's Config4 CP0
929 * register, by userland (currently read-only to the guest).
930 */
931 unsigned int kvm_mips_config4_wrmask(struct kvm_vcpu *vcpu)
932 {
933 /* Config5 is optional */
934 return MIPS_CONF_M;
935 }
936
937 /**
938 * kvm_mips_config5_wrmask() - Find mask of writable bits in guest Config5
939 * @vcpu: Virtual CPU.
940 *
941 * Finds the mask of bits which are writable in the guest's Config5 CP0
942 * register, by the guest itself.
943 */
944 unsigned int kvm_mips_config5_wrmask(struct kvm_vcpu *vcpu)
945 {
946 unsigned int mask = 0;
947
948 /* Permit MSAEn changes if MSA supported and enabled */
949 if (kvm_mips_guest_has_msa(&vcpu->arch))
950 mask |= MIPS_CONF5_MSAEN;
951
952 /*
953 * Permit guest FPU mode changes if FPU is enabled and the relevant
954 * feature exists according to FIR register.
955 */
956 if (kvm_mips_guest_has_fpu(&vcpu->arch)) {
957 if (cpu_has_fre)
958 mask |= MIPS_CONF5_FRE;
959 /* We don't support UFR or UFE */
960 }
961
962 return mask;
963 }
964
965 enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc,
966 uint32_t cause, struct kvm_run *run,
967 struct kvm_vcpu *vcpu)
968 {
969 struct mips_coproc *cop0 = vcpu->arch.cop0;
970 enum emulation_result er = EMULATE_DONE;
971 int32_t rt, rd, copz, sel, co_bit, op;
972 uint32_t pc = vcpu->arch.pc;
973 unsigned long curr_pc;
974
975 /*
976 * Update PC and hold onto current PC in case there is
977 * an error and we want to rollback the PC
978 */
979 curr_pc = vcpu->arch.pc;
980 er = update_pc(vcpu, cause);
981 if (er == EMULATE_FAIL)
982 return er;
983
984 copz = (inst >> 21) & 0x1f;
985 rt = (inst >> 16) & 0x1f;
986 rd = (inst >> 11) & 0x1f;
987 sel = inst & 0x7;
988 co_bit = (inst >> 25) & 1;
989
990 if (co_bit) {
991 op = (inst) & 0xff;
992
993 switch (op) {
994 case tlbr_op: /* Read indexed TLB entry */
995 er = kvm_mips_emul_tlbr(vcpu);
996 break;
997 case tlbwi_op: /* Write indexed */
998 er = kvm_mips_emul_tlbwi(vcpu);
999 break;
1000 case tlbwr_op: /* Write random */
1001 er = kvm_mips_emul_tlbwr(vcpu);
1002 break;
1003 case tlbp_op: /* TLB Probe */
1004 er = kvm_mips_emul_tlbp(vcpu);
1005 break;
1006 case rfe_op:
1007 kvm_err("!!!COP0_RFE!!!\n");
1008 break;
1009 case eret_op:
1010 er = kvm_mips_emul_eret(vcpu);
1011 goto dont_update_pc;
1012 break;
1013 case wait_op:
1014 er = kvm_mips_emul_wait(vcpu);
1015 break;
1016 }
1017 } else {
1018 switch (copz) {
1019 case mfc_op:
1020 #ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
1021 cop0->stat[rd][sel]++;
1022 #endif
1023 /* Get reg */
1024 if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
1025 vcpu->arch.gprs[rt] = kvm_mips_read_count(vcpu);
1026 } else if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) {
1027 vcpu->arch.gprs[rt] = 0x0;
1028 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1029 kvm_mips_trans_mfc0(inst, opc, vcpu);
1030 #endif
1031 } else {
1032 vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
1033
1034 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1035 kvm_mips_trans_mfc0(inst, opc, vcpu);
1036 #endif
1037 }
1038
1039 kvm_debug
1040 ("[%#x] MFCz[%d][%d], vcpu->arch.gprs[%d]: %#lx\n",
1041 pc, rd, sel, rt, vcpu->arch.gprs[rt]);
1042
1043 break;
1044
1045 case dmfc_op:
1046 vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
1047 break;
1048
1049 case mtc_op:
1050 #ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
1051 cop0->stat[rd][sel]++;
1052 #endif
1053 if ((rd == MIPS_CP0_TLB_INDEX)
1054 && (vcpu->arch.gprs[rt] >=
1055 KVM_MIPS_GUEST_TLB_SIZE)) {
1056 kvm_err("Invalid TLB Index: %ld",
1057 vcpu->arch.gprs[rt]);
1058 er = EMULATE_FAIL;
1059 break;
1060 }
1061 #define C0_EBASE_CORE_MASK 0xff
1062 if ((rd == MIPS_CP0_PRID) && (sel == 1)) {
1063 /* Preserve CORE number */
1064 kvm_change_c0_guest_ebase(cop0,
1065 ~(C0_EBASE_CORE_MASK),
1066 vcpu->arch.gprs[rt]);
1067 kvm_err("MTCz, cop0->reg[EBASE]: %#lx\n",
1068 kvm_read_c0_guest_ebase(cop0));
1069 } else if (rd == MIPS_CP0_TLB_HI && sel == 0) {
1070 uint32_t nasid =
1071 vcpu->arch.gprs[rt] & ASID_MASK;
1072 if ((KSEGX(vcpu->arch.gprs[rt]) != CKSEG0) &&
1073 ((kvm_read_c0_guest_entryhi(cop0) &
1074 ASID_MASK) != nasid)) {
1075 kvm_debug("MTCz, change ASID from %#lx to %#lx\n",
1076 kvm_read_c0_guest_entryhi(cop0)
1077 & ASID_MASK,
1078 vcpu->arch.gprs[rt]
1079 & ASID_MASK);
1080
1081 /* Blow away the shadow host TLBs */
1082 kvm_mips_flush_host_tlb(1);
1083 }
1084 kvm_write_c0_guest_entryhi(cop0,
1085 vcpu->arch.gprs[rt]);
1086 }
1087 /* Are we writing to COUNT */
1088 else if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
1089 kvm_mips_write_count(vcpu, vcpu->arch.gprs[rt]);
1090 goto done;
1091 } else if ((rd == MIPS_CP0_COMPARE) && (sel == 0)) {
1092 kvm_debug("[%#x] MTCz, COMPARE %#lx <- %#lx\n",
1093 pc, kvm_read_c0_guest_compare(cop0),
1094 vcpu->arch.gprs[rt]);
1095
1096 /* If we are writing to COMPARE */
1097 /* Clear pending timer interrupt, if any */
1098 kvm_mips_callbacks->dequeue_timer_int(vcpu);
1099 kvm_mips_write_compare(vcpu,
1100 vcpu->arch.gprs[rt]);
1101 } else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) {
1102 unsigned int old_val, val, change;
1103
1104 old_val = kvm_read_c0_guest_status(cop0);
1105 val = vcpu->arch.gprs[rt];
1106 change = val ^ old_val;
1107
1108 /* Make sure that the NMI bit is never set */
1109 val &= ~ST0_NMI;
1110
1111 /*
1112 * Don't allow CU1 or FR to be set unless FPU
1113 * capability enabled and exists in guest
1114 * configuration.
1115 */
1116 if (!kvm_mips_guest_has_fpu(&vcpu->arch))
1117 val &= ~(ST0_CU1 | ST0_FR);
1118
1119 /*
1120 * Also don't allow FR to be set if host doesn't
1121 * support it.
1122 */
1123 if (!(current_cpu_data.fpu_id & MIPS_FPIR_F64))
1124 val &= ~ST0_FR;
1125
1126
1127 /* Handle changes in FPU mode */
1128 preempt_disable();
1129
1130 /*
1131 * FPU and Vector register state is made
1132 * UNPREDICTABLE by a change of FR, so don't
1133 * even bother saving it.
1134 */
1135 if (change & ST0_FR)
1136 kvm_drop_fpu(vcpu);
1137
1138 /*
1139 * If MSA state is already live, it is undefined
1140 * how it interacts with FR=0 FPU state, and we
1141 * don't want to hit reserved instruction
1142 * exceptions trying to save the MSA state later
1143 * when CU=1 && FR=1, so play it safe and save
1144 * it first.
1145 */
1146 if (change & ST0_CU1 && !(val & ST0_FR) &&
1147 vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA)
1148 kvm_lose_fpu(vcpu);
1149
1150 /*
1151 * Propagate CU1 (FPU enable) changes
1152 * immediately if the FPU context is already
1153 * loaded. When disabling we leave the context
1154 * loaded so it can be quickly enabled again in
1155 * the near future.
1156 */
1157 if (change & ST0_CU1 &&
1158 vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)
1159 change_c0_status(ST0_CU1, val);
1160
1161 preempt_enable();
1162
1163 kvm_write_c0_guest_status(cop0, val);
1164
1165 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1166 /*
1167 * If FPU present, we need CU1/FR bits to take
1168 * effect fairly soon.
1169 */
1170 if (!kvm_mips_guest_has_fpu(&vcpu->arch))
1171 kvm_mips_trans_mtc0(inst, opc, vcpu);
1172 #endif
1173 } else if ((rd == MIPS_CP0_CONFIG) && (sel == 5)) {
1174 unsigned int old_val, val, change, wrmask;
1175
1176 old_val = kvm_read_c0_guest_config5(cop0);
1177 val = vcpu->arch.gprs[rt];
1178
1179 /* Only a few bits are writable in Config5 */
1180 wrmask = kvm_mips_config5_wrmask(vcpu);
1181 change = (val ^ old_val) & wrmask;
1182 val = old_val ^ change;
1183
1184
1185 /* Handle changes in FPU/MSA modes */
1186 preempt_disable();
1187
1188 /*
1189 * Propagate FRE changes immediately if the FPU
1190 * context is already loaded.
1191 */
1192 if (change & MIPS_CONF5_FRE &&
1193 vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)
1194 change_c0_config5(MIPS_CONF5_FRE, val);
1195
1196 /*
1197 * Propagate MSAEn changes immediately if the
1198 * MSA context is already loaded. When disabling
1199 * we leave the context loaded so it can be
1200 * quickly enabled again in the near future.
1201 */
1202 if (change & MIPS_CONF5_MSAEN &&
1203 vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA)
1204 change_c0_config5(MIPS_CONF5_MSAEN,
1205 val);
1206
1207 preempt_enable();
1208
1209 kvm_write_c0_guest_config5(cop0, val);
1210 } else if ((rd == MIPS_CP0_CAUSE) && (sel == 0)) {
1211 uint32_t old_cause, new_cause;
1212
1213 old_cause = kvm_read_c0_guest_cause(cop0);
1214 new_cause = vcpu->arch.gprs[rt];
1215 /* Update R/W bits */
1216 kvm_change_c0_guest_cause(cop0, 0x08800300,
1217 new_cause);
1218 /* DC bit enabling/disabling timer? */
1219 if ((old_cause ^ new_cause) & CAUSEF_DC) {
1220 if (new_cause & CAUSEF_DC)
1221 kvm_mips_count_disable_cause(vcpu);
1222 else
1223 kvm_mips_count_enable_cause(vcpu);
1224 }
1225 } else {
1226 cop0->reg[rd][sel] = vcpu->arch.gprs[rt];
1227 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1228 kvm_mips_trans_mtc0(inst, opc, vcpu);
1229 #endif
1230 }
1231
1232 kvm_debug("[%#x] MTCz, cop0->reg[%d][%d]: %#lx\n", pc,
1233 rd, sel, cop0->reg[rd][sel]);
1234 break;
1235
1236 case dmtc_op:
1237 kvm_err("!!!!!!![%#lx]dmtc_op: rt: %d, rd: %d, sel: %d!!!!!!\n",
1238 vcpu->arch.pc, rt, rd, sel);
1239 er = EMULATE_FAIL;
1240 break;
1241
1242 case mfmcz_op:
1243 #ifdef KVM_MIPS_DEBUG_COP0_COUNTERS
1244 cop0->stat[MIPS_CP0_STATUS][0]++;
1245 #endif
1246 if (rt != 0) {
1247 vcpu->arch.gprs[rt] =
1248 kvm_read_c0_guest_status(cop0);
1249 }
1250 /* EI */
1251 if (inst & 0x20) {
1252 kvm_debug("[%#lx] mfmcz_op: EI\n",
1253 vcpu->arch.pc);
1254 kvm_set_c0_guest_status(cop0, ST0_IE);
1255 } else {
1256 kvm_debug("[%#lx] mfmcz_op: DI\n",
1257 vcpu->arch.pc);
1258 kvm_clear_c0_guest_status(cop0, ST0_IE);
1259 }
1260
1261 break;
1262
1263 case wrpgpr_op:
1264 {
1265 uint32_t css =
1266 cop0->reg[MIPS_CP0_STATUS][2] & 0xf;
1267 uint32_t pss =
1268 (cop0->reg[MIPS_CP0_STATUS][2] >> 6) & 0xf;
1269 /*
1270 * We don't support any shadow register sets, so
1271 * SRSCtl[PSS] == SRSCtl[CSS] = 0
1272 */
1273 if (css || pss) {
1274 er = EMULATE_FAIL;
1275 break;
1276 }
1277 kvm_debug("WRPGPR[%d][%d] = %#lx\n", pss, rd,
1278 vcpu->arch.gprs[rt]);
1279 vcpu->arch.gprs[rd] = vcpu->arch.gprs[rt];
1280 }
1281 break;
1282 default:
1283 kvm_err("[%#lx]MachEmulateCP0: unsupported COP0, copz: 0x%x\n",
1284 vcpu->arch.pc, copz);
1285 er = EMULATE_FAIL;
1286 break;
1287 }
1288 }
1289
1290 done:
1291 /* Rollback PC only if emulation was unsuccessful */
1292 if (er == EMULATE_FAIL)
1293 vcpu->arch.pc = curr_pc;
1294
1295 dont_update_pc:
1296 /*
1297 * This is for special instructions whose emulation
1298 * updates the PC, so do not overwrite the PC under
1299 * any circumstances
1300 */
1301
1302 return er;
1303 }
1304
1305 enum emulation_result kvm_mips_emulate_store(uint32_t inst, uint32_t cause,
1306 struct kvm_run *run,
1307 struct kvm_vcpu *vcpu)
1308 {
1309 enum emulation_result er = EMULATE_DO_MMIO;
1310 int32_t op, base, rt, offset;
1311 uint32_t bytes;
1312 void *data = run->mmio.data;
1313 unsigned long curr_pc;
1314
1315 /*
1316 * Update PC and hold onto current PC in case there is
1317 * an error and we want to rollback the PC
1318 */
1319 curr_pc = vcpu->arch.pc;
1320 er = update_pc(vcpu, cause);
1321 if (er == EMULATE_FAIL)
1322 return er;
1323
1324 rt = (inst >> 16) & 0x1f;
1325 base = (inst >> 21) & 0x1f;
1326 offset = inst & 0xffff;
1327 op = (inst >> 26) & 0x3f;
1328
1329 switch (op) {
1330 case sb_op:
1331 bytes = 1;
1332 if (bytes > sizeof(run->mmio.data)) {
1333 kvm_err("%s: bad MMIO length: %d\n", __func__,
1334 run->mmio.len);
1335 }
1336 run->mmio.phys_addr =
1337 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1338 host_cp0_badvaddr);
1339 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1340 er = EMULATE_FAIL;
1341 break;
1342 }
1343 run->mmio.len = bytes;
1344 run->mmio.is_write = 1;
1345 vcpu->mmio_needed = 1;
1346 vcpu->mmio_is_write = 1;
1347 *(u8 *) data = vcpu->arch.gprs[rt];
1348 kvm_debug("OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1349 vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt],
1350 *(uint8_t *) data);
1351
1352 break;
1353
1354 case sw_op:
1355 bytes = 4;
1356 if (bytes > sizeof(run->mmio.data)) {
1357 kvm_err("%s: bad MMIO length: %d\n", __func__,
1358 run->mmio.len);
1359 }
1360 run->mmio.phys_addr =
1361 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1362 host_cp0_badvaddr);
1363 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1364 er = EMULATE_FAIL;
1365 break;
1366 }
1367
1368 run->mmio.len = bytes;
1369 run->mmio.is_write = 1;
1370 vcpu->mmio_needed = 1;
1371 vcpu->mmio_is_write = 1;
1372 *(uint32_t *) data = vcpu->arch.gprs[rt];
1373
1374 kvm_debug("[%#lx] OP_SW: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1375 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1376 vcpu->arch.gprs[rt], *(uint32_t *) data);
1377 break;
1378
1379 case sh_op:
1380 bytes = 2;
1381 if (bytes > sizeof(run->mmio.data)) {
1382 kvm_err("%s: bad MMIO length: %d\n", __func__,
1383 run->mmio.len);
1384 }
1385 run->mmio.phys_addr =
1386 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1387 host_cp0_badvaddr);
1388 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1389 er = EMULATE_FAIL;
1390 break;
1391 }
1392
1393 run->mmio.len = bytes;
1394 run->mmio.is_write = 1;
1395 vcpu->mmio_needed = 1;
1396 vcpu->mmio_is_write = 1;
1397 *(uint16_t *) data = vcpu->arch.gprs[rt];
1398
1399 kvm_debug("[%#lx] OP_SH: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1400 vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1401 vcpu->arch.gprs[rt], *(uint32_t *) data);
1402 break;
1403
1404 default:
1405 kvm_err("Store not yet supported");
1406 er = EMULATE_FAIL;
1407 break;
1408 }
1409
1410 /* Rollback PC if emulation was unsuccessful */
1411 if (er == EMULATE_FAIL)
1412 vcpu->arch.pc = curr_pc;
1413
1414 return er;
1415 }
1416
1417 enum emulation_result kvm_mips_emulate_load(uint32_t inst, uint32_t cause,
1418 struct kvm_run *run,
1419 struct kvm_vcpu *vcpu)
1420 {
1421 enum emulation_result er = EMULATE_DO_MMIO;
1422 int32_t op, base, rt, offset;
1423 uint32_t bytes;
1424
1425 rt = (inst >> 16) & 0x1f;
1426 base = (inst >> 21) & 0x1f;
1427 offset = inst & 0xffff;
1428 op = (inst >> 26) & 0x3f;
1429
1430 vcpu->arch.pending_load_cause = cause;
1431 vcpu->arch.io_gpr = rt;
1432
1433 switch (op) {
1434 case lw_op:
1435 bytes = 4;
1436 if (bytes > sizeof(run->mmio.data)) {
1437 kvm_err("%s: bad MMIO length: %d\n", __func__,
1438 run->mmio.len);
1439 er = EMULATE_FAIL;
1440 break;
1441 }
1442 run->mmio.phys_addr =
1443 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1444 host_cp0_badvaddr);
1445 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1446 er = EMULATE_FAIL;
1447 break;
1448 }
1449
1450 run->mmio.len = bytes;
1451 run->mmio.is_write = 0;
1452 vcpu->mmio_needed = 1;
1453 vcpu->mmio_is_write = 0;
1454 break;
1455
1456 case lh_op:
1457 case lhu_op:
1458 bytes = 2;
1459 if (bytes > sizeof(run->mmio.data)) {
1460 kvm_err("%s: bad MMIO length: %d\n", __func__,
1461 run->mmio.len);
1462 er = EMULATE_FAIL;
1463 break;
1464 }
1465 run->mmio.phys_addr =
1466 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1467 host_cp0_badvaddr);
1468 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1469 er = EMULATE_FAIL;
1470 break;
1471 }
1472
1473 run->mmio.len = bytes;
1474 run->mmio.is_write = 0;
1475 vcpu->mmio_needed = 1;
1476 vcpu->mmio_is_write = 0;
1477
1478 if (op == lh_op)
1479 vcpu->mmio_needed = 2;
1480 else
1481 vcpu->mmio_needed = 1;
1482
1483 break;
1484
1485 case lbu_op:
1486 case lb_op:
1487 bytes = 1;
1488 if (bytes > sizeof(run->mmio.data)) {
1489 kvm_err("%s: bad MMIO length: %d\n", __func__,
1490 run->mmio.len);
1491 er = EMULATE_FAIL;
1492 break;
1493 }
1494 run->mmio.phys_addr =
1495 kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1496 host_cp0_badvaddr);
1497 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1498 er = EMULATE_FAIL;
1499 break;
1500 }
1501
1502 run->mmio.len = bytes;
1503 run->mmio.is_write = 0;
1504 vcpu->mmio_is_write = 0;
1505
1506 if (op == lb_op)
1507 vcpu->mmio_needed = 2;
1508 else
1509 vcpu->mmio_needed = 1;
1510
1511 break;
1512
1513 default:
1514 kvm_err("Load not yet supported");
1515 er = EMULATE_FAIL;
1516 break;
1517 }
1518
1519 return er;
1520 }
1521
1522 int kvm_mips_sync_icache(unsigned long va, struct kvm_vcpu *vcpu)
1523 {
1524 unsigned long offset = (va & ~PAGE_MASK);
1525 struct kvm *kvm = vcpu->kvm;
1526 unsigned long pa;
1527 gfn_t gfn;
1528 pfn_t pfn;
1529
1530 gfn = va >> PAGE_SHIFT;
1531
1532 if (gfn >= kvm->arch.guest_pmap_npages) {
1533 kvm_err("%s: Invalid gfn: %#llx\n", __func__, gfn);
1534 kvm_mips_dump_host_tlbs();
1535 kvm_arch_vcpu_dump_regs(vcpu);
1536 return -1;
1537 }
1538 pfn = kvm->arch.guest_pmap[gfn];
1539 pa = (pfn << PAGE_SHIFT) | offset;
1540
1541 kvm_debug("%s: va: %#lx, unmapped: %#x\n", __func__, va,
1542 CKSEG0ADDR(pa));
1543
1544 local_flush_icache_range(CKSEG0ADDR(pa), 32);
1545 return 0;
1546 }
1547
1548 #define MIPS_CACHE_OP_INDEX_INV 0x0
1549 #define MIPS_CACHE_OP_INDEX_LD_TAG 0x1
1550 #define MIPS_CACHE_OP_INDEX_ST_TAG 0x2
1551 #define MIPS_CACHE_OP_IMP 0x3
1552 #define MIPS_CACHE_OP_HIT_INV 0x4
1553 #define MIPS_CACHE_OP_FILL_WB_INV 0x5
1554 #define MIPS_CACHE_OP_HIT_HB 0x6
1555 #define MIPS_CACHE_OP_FETCH_LOCK 0x7
1556
1557 #define MIPS_CACHE_ICACHE 0x0
1558 #define MIPS_CACHE_DCACHE 0x1
1559 #define MIPS_CACHE_SEC 0x3
1560
1561 enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc,
1562 uint32_t cause,
1563 struct kvm_run *run,
1564 struct kvm_vcpu *vcpu)
1565 {
1566 struct mips_coproc *cop0 = vcpu->arch.cop0;
1567 enum emulation_result er = EMULATE_DONE;
1568 int32_t offset, cache, op_inst, op, base;
1569 struct kvm_vcpu_arch *arch = &vcpu->arch;
1570 unsigned long va;
1571 unsigned long curr_pc;
1572
1573 /*
1574 * Update PC and hold onto current PC in case there is
1575 * an error and we want to rollback the PC
1576 */
1577 curr_pc = vcpu->arch.pc;
1578 er = update_pc(vcpu, cause);
1579 if (er == EMULATE_FAIL)
1580 return er;
1581
1582 base = (inst >> 21) & 0x1f;
1583 op_inst = (inst >> 16) & 0x1f;
1584 offset = inst & 0xffff;
1585 cache = (inst >> 16) & 0x3;
1586 op = (inst >> 18) & 0x7;
1587
1588 va = arch->gprs[base] + offset;
1589
1590 kvm_debug("CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1591 cache, op, base, arch->gprs[base], offset);
1592
1593 /*
1594 * Treat INDEX_INV as a nop, basically issued by Linux on startup to
1595 * invalidate the caches entirely by stepping through all the
1596 * ways/indexes
1597 */
1598 if (op == MIPS_CACHE_OP_INDEX_INV) {
1599 kvm_debug("@ %#lx/%#lx CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1600 vcpu->arch.pc, vcpu->arch.gprs[31], cache, op, base,
1601 arch->gprs[base], offset);
1602
1603 if (cache == MIPS_CACHE_DCACHE)
1604 r4k_blast_dcache();
1605 else if (cache == MIPS_CACHE_ICACHE)
1606 r4k_blast_icache();
1607 else {
1608 kvm_err("%s: unsupported CACHE INDEX operation\n",
1609 __func__);
1610 return EMULATE_FAIL;
1611 }
1612
1613 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1614 kvm_mips_trans_cache_index(inst, opc, vcpu);
1615 #endif
1616 goto done;
1617 }
1618
1619 preempt_disable();
1620 if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
1621 if (kvm_mips_host_tlb_lookup(vcpu, va) < 0)
1622 kvm_mips_handle_kseg0_tlb_fault(va, vcpu);
1623 } else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) ||
1624 KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
1625 int index;
1626
1627 /* If an entry already exists then skip */
1628 if (kvm_mips_host_tlb_lookup(vcpu, va) >= 0)
1629 goto skip_fault;
1630
1631 /*
1632 * If address not in the guest TLB, then give the guest a fault,
1633 * the resulting handler will do the right thing
1634 */
1635 index = kvm_mips_guest_tlb_lookup(vcpu, (va & VPN2_MASK) |
1636 (kvm_read_c0_guest_entryhi
1637 (cop0) & ASID_MASK));
1638
1639 if (index < 0) {
1640 vcpu->arch.host_cp0_entryhi = (va & VPN2_MASK);
1641 vcpu->arch.host_cp0_badvaddr = va;
1642 er = kvm_mips_emulate_tlbmiss_ld(cause, NULL, run,
1643 vcpu);
1644 preempt_enable();
1645 goto dont_update_pc;
1646 } else {
1647 struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
1648 /*
1649 * Check if the entry is valid, if not then setup a TLB
1650 * invalid exception to the guest
1651 */
1652 if (!TLB_IS_VALID(*tlb, va)) {
1653 er = kvm_mips_emulate_tlbinv_ld(cause, NULL,
1654 run, vcpu);
1655 preempt_enable();
1656 goto dont_update_pc;
1657 } else {
1658 /*
1659 * We fault an entry from the guest tlb to the
1660 * shadow host TLB
1661 */
1662 kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
1663 NULL,
1664 NULL);
1665 }
1666 }
1667 } else {
1668 kvm_err("INVALID CACHE INDEX/ADDRESS (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1669 cache, op, base, arch->gprs[base], offset);
1670 er = EMULATE_FAIL;
1671 preempt_enable();
1672 goto dont_update_pc;
1673
1674 }
1675
1676 skip_fault:
1677 /* XXXKYMA: Only a subset of cache ops are supported, used by Linux */
1678 if (cache == MIPS_CACHE_DCACHE
1679 && (op == MIPS_CACHE_OP_FILL_WB_INV
1680 || op == MIPS_CACHE_OP_HIT_INV)) {
1681 flush_dcache_line(va);
1682
1683 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1684 /*
1685 * Replace the CACHE instruction, with a SYNCI, not the same,
1686 * but avoids a trap
1687 */
1688 kvm_mips_trans_cache_va(inst, opc, vcpu);
1689 #endif
1690 } else if (op == MIPS_CACHE_OP_HIT_INV && cache == MIPS_CACHE_ICACHE) {
1691 flush_dcache_line(va);
1692 flush_icache_line(va);
1693
1694 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1695 /* Replace the CACHE instruction, with a SYNCI */
1696 kvm_mips_trans_cache_va(inst, opc, vcpu);
1697 #endif
1698 } else {
1699 kvm_err("NO-OP CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1700 cache, op, base, arch->gprs[base], offset);
1701 er = EMULATE_FAIL;
1702 preempt_enable();
1703 goto dont_update_pc;
1704 }
1705
1706 preempt_enable();
1707
1708 dont_update_pc:
1709 /* Rollback PC */
1710 vcpu->arch.pc = curr_pc;
1711 done:
1712 return er;
1713 }
1714
1715 enum emulation_result kvm_mips_emulate_inst(unsigned long cause, uint32_t *opc,
1716 struct kvm_run *run,
1717 struct kvm_vcpu *vcpu)
1718 {
1719 enum emulation_result er = EMULATE_DONE;
1720 uint32_t inst;
1721
1722 /* Fetch the instruction. */
1723 if (cause & CAUSEF_BD)
1724 opc += 1;
1725
1726 inst = kvm_get_inst(opc, vcpu);
1727
1728 switch (((union mips_instruction)inst).r_format.opcode) {
1729 case cop0_op:
1730 er = kvm_mips_emulate_CP0(inst, opc, cause, run, vcpu);
1731 break;
1732 case sb_op:
1733 case sh_op:
1734 case sw_op:
1735 er = kvm_mips_emulate_store(inst, cause, run, vcpu);
1736 break;
1737 case lb_op:
1738 case lbu_op:
1739 case lhu_op:
1740 case lh_op:
1741 case lw_op:
1742 er = kvm_mips_emulate_load(inst, cause, run, vcpu);
1743 break;
1744
1745 case cache_op:
1746 ++vcpu->stat.cache_exits;
1747 trace_kvm_exit(vcpu, CACHE_EXITS);
1748 er = kvm_mips_emulate_cache(inst, opc, cause, run, vcpu);
1749 break;
1750
1751 default:
1752 kvm_err("Instruction emulation not supported (%p/%#x)\n", opc,
1753 inst);
1754 kvm_arch_vcpu_dump_regs(vcpu);
1755 er = EMULATE_FAIL;
1756 break;
1757 }
1758
1759 return er;
1760 }
1761
1762 enum emulation_result kvm_mips_emulate_syscall(unsigned long cause,
1763 uint32_t *opc,
1764 struct kvm_run *run,
1765 struct kvm_vcpu *vcpu)
1766 {
1767 struct mips_coproc *cop0 = vcpu->arch.cop0;
1768 struct kvm_vcpu_arch *arch = &vcpu->arch;
1769 enum emulation_result er = EMULATE_DONE;
1770
1771 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1772 /* save old pc */
1773 kvm_write_c0_guest_epc(cop0, arch->pc);
1774 kvm_set_c0_guest_status(cop0, ST0_EXL);
1775
1776 if (cause & CAUSEF_BD)
1777 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1778 else
1779 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1780
1781 kvm_debug("Delivering SYSCALL @ pc %#lx\n", arch->pc);
1782
1783 kvm_change_c0_guest_cause(cop0, (0xff),
1784 (T_SYSCALL << CAUSEB_EXCCODE));
1785
1786 /* Set PC to the exception entry point */
1787 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1788
1789 } else {
1790 kvm_err("Trying to deliver SYSCALL when EXL is already set\n");
1791 er = EMULATE_FAIL;
1792 }
1793
1794 return er;
1795 }
1796
1797 enum emulation_result kvm_mips_emulate_tlbmiss_ld(unsigned long cause,
1798 uint32_t *opc,
1799 struct kvm_run *run,
1800 struct kvm_vcpu *vcpu)
1801 {
1802 struct mips_coproc *cop0 = vcpu->arch.cop0;
1803 struct kvm_vcpu_arch *arch = &vcpu->arch;
1804 unsigned long entryhi = (vcpu->arch. host_cp0_badvaddr & VPN2_MASK) |
1805 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1806
1807 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1808 /* save old pc */
1809 kvm_write_c0_guest_epc(cop0, arch->pc);
1810 kvm_set_c0_guest_status(cop0, ST0_EXL);
1811
1812 if (cause & CAUSEF_BD)
1813 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1814 else
1815 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1816
1817 kvm_debug("[EXL == 0] delivering TLB MISS @ pc %#lx\n",
1818 arch->pc);
1819
1820 /* set pc to the exception entry point */
1821 arch->pc = KVM_GUEST_KSEG0 + 0x0;
1822
1823 } else {
1824 kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1825 arch->pc);
1826
1827 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1828 }
1829
1830 kvm_change_c0_guest_cause(cop0, (0xff),
1831 (T_TLB_LD_MISS << CAUSEB_EXCCODE));
1832
1833 /* setup badvaddr, context and entryhi registers for the guest */
1834 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1835 /* XXXKYMA: is the context register used by linux??? */
1836 kvm_write_c0_guest_entryhi(cop0, entryhi);
1837 /* Blow away the shadow host TLBs */
1838 kvm_mips_flush_host_tlb(1);
1839
1840 return EMULATE_DONE;
1841 }
1842
1843 enum emulation_result kvm_mips_emulate_tlbinv_ld(unsigned long cause,
1844 uint32_t *opc,
1845 struct kvm_run *run,
1846 struct kvm_vcpu *vcpu)
1847 {
1848 struct mips_coproc *cop0 = vcpu->arch.cop0;
1849 struct kvm_vcpu_arch *arch = &vcpu->arch;
1850 unsigned long entryhi =
1851 (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1852 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1853
1854 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1855 /* save old pc */
1856 kvm_write_c0_guest_epc(cop0, arch->pc);
1857 kvm_set_c0_guest_status(cop0, ST0_EXL);
1858
1859 if (cause & CAUSEF_BD)
1860 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1861 else
1862 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1863
1864 kvm_debug("[EXL == 0] delivering TLB INV @ pc %#lx\n",
1865 arch->pc);
1866
1867 /* set pc to the exception entry point */
1868 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1869
1870 } else {
1871 kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1872 arch->pc);
1873 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1874 }
1875
1876 kvm_change_c0_guest_cause(cop0, (0xff),
1877 (T_TLB_LD_MISS << CAUSEB_EXCCODE));
1878
1879 /* setup badvaddr, context and entryhi registers for the guest */
1880 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1881 /* XXXKYMA: is the context register used by linux??? */
1882 kvm_write_c0_guest_entryhi(cop0, entryhi);
1883 /* Blow away the shadow host TLBs */
1884 kvm_mips_flush_host_tlb(1);
1885
1886 return EMULATE_DONE;
1887 }
1888
1889 enum emulation_result kvm_mips_emulate_tlbmiss_st(unsigned long cause,
1890 uint32_t *opc,
1891 struct kvm_run *run,
1892 struct kvm_vcpu *vcpu)
1893 {
1894 struct mips_coproc *cop0 = vcpu->arch.cop0;
1895 struct kvm_vcpu_arch *arch = &vcpu->arch;
1896 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1897 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1898
1899 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1900 /* save old pc */
1901 kvm_write_c0_guest_epc(cop0, arch->pc);
1902 kvm_set_c0_guest_status(cop0, ST0_EXL);
1903
1904 if (cause & CAUSEF_BD)
1905 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1906 else
1907 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1908
1909 kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
1910 arch->pc);
1911
1912 /* Set PC to the exception entry point */
1913 arch->pc = KVM_GUEST_KSEG0 + 0x0;
1914 } else {
1915 kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
1916 arch->pc);
1917 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1918 }
1919
1920 kvm_change_c0_guest_cause(cop0, (0xff),
1921 (T_TLB_ST_MISS << CAUSEB_EXCCODE));
1922
1923 /* setup badvaddr, context and entryhi registers for the guest */
1924 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1925 /* XXXKYMA: is the context register used by linux??? */
1926 kvm_write_c0_guest_entryhi(cop0, entryhi);
1927 /* Blow away the shadow host TLBs */
1928 kvm_mips_flush_host_tlb(1);
1929
1930 return EMULATE_DONE;
1931 }
1932
1933 enum emulation_result kvm_mips_emulate_tlbinv_st(unsigned long cause,
1934 uint32_t *opc,
1935 struct kvm_run *run,
1936 struct kvm_vcpu *vcpu)
1937 {
1938 struct mips_coproc *cop0 = vcpu->arch.cop0;
1939 struct kvm_vcpu_arch *arch = &vcpu->arch;
1940 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1941 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1942
1943 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1944 /* save old pc */
1945 kvm_write_c0_guest_epc(cop0, arch->pc);
1946 kvm_set_c0_guest_status(cop0, ST0_EXL);
1947
1948 if (cause & CAUSEF_BD)
1949 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1950 else
1951 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1952
1953 kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
1954 arch->pc);
1955
1956 /* Set PC to the exception entry point */
1957 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1958 } else {
1959 kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
1960 arch->pc);
1961 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1962 }
1963
1964 kvm_change_c0_guest_cause(cop0, (0xff),
1965 (T_TLB_ST_MISS << CAUSEB_EXCCODE));
1966
1967 /* setup badvaddr, context and entryhi registers for the guest */
1968 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1969 /* XXXKYMA: is the context register used by linux??? */
1970 kvm_write_c0_guest_entryhi(cop0, entryhi);
1971 /* Blow away the shadow host TLBs */
1972 kvm_mips_flush_host_tlb(1);
1973
1974 return EMULATE_DONE;
1975 }
1976
1977 /* TLBMOD: store into address matching TLB with Dirty bit off */
1978 enum emulation_result kvm_mips_handle_tlbmod(unsigned long cause, uint32_t *opc,
1979 struct kvm_run *run,
1980 struct kvm_vcpu *vcpu)
1981 {
1982 enum emulation_result er = EMULATE_DONE;
1983 #ifdef DEBUG
1984 struct mips_coproc *cop0 = vcpu->arch.cop0;
1985 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1986 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1987 int index;
1988
1989 /* If address not in the guest TLB, then we are in trouble */
1990 index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
1991 if (index < 0) {
1992 /* XXXKYMA Invalidate and retry */
1993 kvm_mips_host_tlb_inv(vcpu, vcpu->arch.host_cp0_badvaddr);
1994 kvm_err("%s: host got TLBMOD for %#lx but entry not present in Guest TLB\n",
1995 __func__, entryhi);
1996 kvm_mips_dump_guest_tlbs(vcpu);
1997 kvm_mips_dump_host_tlbs();
1998 return EMULATE_FAIL;
1999 }
2000 #endif
2001
2002 er = kvm_mips_emulate_tlbmod(cause, opc, run, vcpu);
2003 return er;
2004 }
2005
2006 enum emulation_result kvm_mips_emulate_tlbmod(unsigned long cause,
2007 uint32_t *opc,
2008 struct kvm_run *run,
2009 struct kvm_vcpu *vcpu)
2010 {
2011 struct mips_coproc *cop0 = vcpu->arch.cop0;
2012 unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
2013 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
2014 struct kvm_vcpu_arch *arch = &vcpu->arch;
2015
2016 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2017 /* save old pc */
2018 kvm_write_c0_guest_epc(cop0, arch->pc);
2019 kvm_set_c0_guest_status(cop0, ST0_EXL);
2020
2021 if (cause & CAUSEF_BD)
2022 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2023 else
2024 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2025
2026 kvm_debug("[EXL == 0] Delivering TLB MOD @ pc %#lx\n",
2027 arch->pc);
2028
2029 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2030 } else {
2031 kvm_debug("[EXL == 1] Delivering TLB MOD @ pc %#lx\n",
2032 arch->pc);
2033 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2034 }
2035
2036 kvm_change_c0_guest_cause(cop0, (0xff), (T_TLB_MOD << CAUSEB_EXCCODE));
2037
2038 /* setup badvaddr, context and entryhi registers for the guest */
2039 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2040 /* XXXKYMA: is the context register used by linux??? */
2041 kvm_write_c0_guest_entryhi(cop0, entryhi);
2042 /* Blow away the shadow host TLBs */
2043 kvm_mips_flush_host_tlb(1);
2044
2045 return EMULATE_DONE;
2046 }
2047
2048 enum emulation_result kvm_mips_emulate_fpu_exc(unsigned long cause,
2049 uint32_t *opc,
2050 struct kvm_run *run,
2051 struct kvm_vcpu *vcpu)
2052 {
2053 struct mips_coproc *cop0 = vcpu->arch.cop0;
2054 struct kvm_vcpu_arch *arch = &vcpu->arch;
2055
2056 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2057 /* save old pc */
2058 kvm_write_c0_guest_epc(cop0, arch->pc);
2059 kvm_set_c0_guest_status(cop0, ST0_EXL);
2060
2061 if (cause & CAUSEF_BD)
2062 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2063 else
2064 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2065
2066 }
2067
2068 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2069
2070 kvm_change_c0_guest_cause(cop0, (0xff),
2071 (T_COP_UNUSABLE << CAUSEB_EXCCODE));
2072 kvm_change_c0_guest_cause(cop0, (CAUSEF_CE), (0x1 << CAUSEB_CE));
2073
2074 return EMULATE_DONE;
2075 }
2076
2077 enum emulation_result kvm_mips_emulate_ri_exc(unsigned long cause,
2078 uint32_t *opc,
2079 struct kvm_run *run,
2080 struct kvm_vcpu *vcpu)
2081 {
2082 struct mips_coproc *cop0 = vcpu->arch.cop0;
2083 struct kvm_vcpu_arch *arch = &vcpu->arch;
2084 enum emulation_result er = EMULATE_DONE;
2085
2086 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2087 /* save old pc */
2088 kvm_write_c0_guest_epc(cop0, arch->pc);
2089 kvm_set_c0_guest_status(cop0, ST0_EXL);
2090
2091 if (cause & CAUSEF_BD)
2092 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2093 else
2094 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2095
2096 kvm_debug("Delivering RI @ pc %#lx\n", arch->pc);
2097
2098 kvm_change_c0_guest_cause(cop0, (0xff),
2099 (T_RES_INST << CAUSEB_EXCCODE));
2100
2101 /* Set PC to the exception entry point */
2102 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2103
2104 } else {
2105 kvm_err("Trying to deliver RI when EXL is already set\n");
2106 er = EMULATE_FAIL;
2107 }
2108
2109 return er;
2110 }
2111
2112 enum emulation_result kvm_mips_emulate_bp_exc(unsigned long cause,
2113 uint32_t *opc,
2114 struct kvm_run *run,
2115 struct kvm_vcpu *vcpu)
2116 {
2117 struct mips_coproc *cop0 = vcpu->arch.cop0;
2118 struct kvm_vcpu_arch *arch = &vcpu->arch;
2119 enum emulation_result er = EMULATE_DONE;
2120
2121 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2122 /* save old pc */
2123 kvm_write_c0_guest_epc(cop0, arch->pc);
2124 kvm_set_c0_guest_status(cop0, ST0_EXL);
2125
2126 if (cause & CAUSEF_BD)
2127 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2128 else
2129 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2130
2131 kvm_debug("Delivering BP @ pc %#lx\n", arch->pc);
2132
2133 kvm_change_c0_guest_cause(cop0, (0xff),
2134 (T_BREAK << CAUSEB_EXCCODE));
2135
2136 /* Set PC to the exception entry point */
2137 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2138
2139 } else {
2140 kvm_err("Trying to deliver BP when EXL is already set\n");
2141 er = EMULATE_FAIL;
2142 }
2143
2144 return er;
2145 }
2146
2147 enum emulation_result kvm_mips_emulate_trap_exc(unsigned long cause,
2148 uint32_t *opc,
2149 struct kvm_run *run,
2150 struct kvm_vcpu *vcpu)
2151 {
2152 struct mips_coproc *cop0 = vcpu->arch.cop0;
2153 struct kvm_vcpu_arch *arch = &vcpu->arch;
2154 enum emulation_result er = EMULATE_DONE;
2155
2156 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2157 /* save old pc */
2158 kvm_write_c0_guest_epc(cop0, arch->pc);
2159 kvm_set_c0_guest_status(cop0, ST0_EXL);
2160
2161 if (cause & CAUSEF_BD)
2162 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2163 else
2164 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2165
2166 kvm_debug("Delivering TRAP @ pc %#lx\n", arch->pc);
2167
2168 kvm_change_c0_guest_cause(cop0, (0xff),
2169 (T_TRAP << CAUSEB_EXCCODE));
2170
2171 /* Set PC to the exception entry point */
2172 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2173
2174 } else {
2175 kvm_err("Trying to deliver TRAP when EXL is already set\n");
2176 er = EMULATE_FAIL;
2177 }
2178
2179 return er;
2180 }
2181
2182 enum emulation_result kvm_mips_emulate_msafpe_exc(unsigned long cause,
2183 uint32_t *opc,
2184 struct kvm_run *run,
2185 struct kvm_vcpu *vcpu)
2186 {
2187 struct mips_coproc *cop0 = vcpu->arch.cop0;
2188 struct kvm_vcpu_arch *arch = &vcpu->arch;
2189 enum emulation_result er = EMULATE_DONE;
2190
2191 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2192 /* save old pc */
2193 kvm_write_c0_guest_epc(cop0, arch->pc);
2194 kvm_set_c0_guest_status(cop0, ST0_EXL);
2195
2196 if (cause & CAUSEF_BD)
2197 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2198 else
2199 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2200
2201 kvm_debug("Delivering MSAFPE @ pc %#lx\n", arch->pc);
2202
2203 kvm_change_c0_guest_cause(cop0, (0xff),
2204 (T_MSAFPE << CAUSEB_EXCCODE));
2205
2206 /* Set PC to the exception entry point */
2207 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2208
2209 } else {
2210 kvm_err("Trying to deliver MSAFPE when EXL is already set\n");
2211 er = EMULATE_FAIL;
2212 }
2213
2214 return er;
2215 }
2216
2217 enum emulation_result kvm_mips_emulate_fpe_exc(unsigned long cause,
2218 uint32_t *opc,
2219 struct kvm_run *run,
2220 struct kvm_vcpu *vcpu)
2221 {
2222 struct mips_coproc *cop0 = vcpu->arch.cop0;
2223 struct kvm_vcpu_arch *arch = &vcpu->arch;
2224 enum emulation_result er = EMULATE_DONE;
2225
2226 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2227 /* save old pc */
2228 kvm_write_c0_guest_epc(cop0, arch->pc);
2229 kvm_set_c0_guest_status(cop0, ST0_EXL);
2230
2231 if (cause & CAUSEF_BD)
2232 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2233 else
2234 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2235
2236 kvm_debug("Delivering FPE @ pc %#lx\n", arch->pc);
2237
2238 kvm_change_c0_guest_cause(cop0, (0xff),
2239 (T_FPE << CAUSEB_EXCCODE));
2240
2241 /* Set PC to the exception entry point */
2242 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2243
2244 } else {
2245 kvm_err("Trying to deliver FPE when EXL is already set\n");
2246 er = EMULATE_FAIL;
2247 }
2248
2249 return er;
2250 }
2251
2252 enum emulation_result kvm_mips_emulate_msadis_exc(unsigned long cause,
2253 uint32_t *opc,
2254 struct kvm_run *run,
2255 struct kvm_vcpu *vcpu)
2256 {
2257 struct mips_coproc *cop0 = vcpu->arch.cop0;
2258 struct kvm_vcpu_arch *arch = &vcpu->arch;
2259 enum emulation_result er = EMULATE_DONE;
2260
2261 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2262 /* save old pc */
2263 kvm_write_c0_guest_epc(cop0, arch->pc);
2264 kvm_set_c0_guest_status(cop0, ST0_EXL);
2265
2266 if (cause & CAUSEF_BD)
2267 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2268 else
2269 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2270
2271 kvm_debug("Delivering MSADIS @ pc %#lx\n", arch->pc);
2272
2273 kvm_change_c0_guest_cause(cop0, (0xff),
2274 (T_MSADIS << CAUSEB_EXCCODE));
2275
2276 /* Set PC to the exception entry point */
2277 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2278
2279 } else {
2280 kvm_err("Trying to deliver MSADIS when EXL is already set\n");
2281 er = EMULATE_FAIL;
2282 }
2283
2284 return er;
2285 }
2286
2287 /* ll/sc, rdhwr, sync emulation */
2288
2289 #define OPCODE 0xfc000000
2290 #define BASE 0x03e00000
2291 #define RT 0x001f0000
2292 #define OFFSET 0x0000ffff
2293 #define LL 0xc0000000
2294 #define SC 0xe0000000
2295 #define SPEC0 0x00000000
2296 #define SPEC3 0x7c000000
2297 #define RD 0x0000f800
2298 #define FUNC 0x0000003f
2299 #define SYNC 0x0000000f
2300 #define RDHWR 0x0000003b
2301
2302 enum emulation_result kvm_mips_handle_ri(unsigned long cause, uint32_t *opc,
2303 struct kvm_run *run,
2304 struct kvm_vcpu *vcpu)
2305 {
2306 struct mips_coproc *cop0 = vcpu->arch.cop0;
2307 struct kvm_vcpu_arch *arch = &vcpu->arch;
2308 enum emulation_result er = EMULATE_DONE;
2309 unsigned long curr_pc;
2310 uint32_t inst;
2311
2312 /*
2313 * Update PC and hold onto current PC in case there is
2314 * an error and we want to rollback the PC
2315 */
2316 curr_pc = vcpu->arch.pc;
2317 er = update_pc(vcpu, cause);
2318 if (er == EMULATE_FAIL)
2319 return er;
2320
2321 /* Fetch the instruction. */
2322 if (cause & CAUSEF_BD)
2323 opc += 1;
2324
2325 inst = kvm_get_inst(opc, vcpu);
2326
2327 if (inst == KVM_INVALID_INST) {
2328 kvm_err("%s: Cannot get inst @ %p\n", __func__, opc);
2329 return EMULATE_FAIL;
2330 }
2331
2332 if ((inst & OPCODE) == SPEC3 && (inst & FUNC) == RDHWR) {
2333 int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
2334 int rd = (inst & RD) >> 11;
2335 int rt = (inst & RT) >> 16;
2336 /* If usermode, check RDHWR rd is allowed by guest HWREna */
2337 if (usermode && !(kvm_read_c0_guest_hwrena(cop0) & BIT(rd))) {
2338 kvm_debug("RDHWR %#x disallowed by HWREna @ %p\n",
2339 rd, opc);
2340 goto emulate_ri;
2341 }
2342 switch (rd) {
2343 case 0: /* CPU number */
2344 arch->gprs[rt] = 0;
2345 break;
2346 case 1: /* SYNCI length */
2347 arch->gprs[rt] = min(current_cpu_data.dcache.linesz,
2348 current_cpu_data.icache.linesz);
2349 break;
2350 case 2: /* Read count register */
2351 arch->gprs[rt] = kvm_mips_read_count(vcpu);
2352 break;
2353 case 3: /* Count register resolution */
2354 switch (current_cpu_data.cputype) {
2355 case CPU_20KC:
2356 case CPU_25KF:
2357 arch->gprs[rt] = 1;
2358 break;
2359 default:
2360 arch->gprs[rt] = 2;
2361 }
2362 break;
2363 case 29:
2364 arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0);
2365 break;
2366
2367 default:
2368 kvm_debug("RDHWR %#x not supported @ %p\n", rd, opc);
2369 goto emulate_ri;
2370 }
2371 } else {
2372 kvm_debug("Emulate RI not supported @ %p: %#x\n", opc, inst);
2373 goto emulate_ri;
2374 }
2375
2376 return EMULATE_DONE;
2377
2378 emulate_ri:
2379 /*
2380 * Rollback PC (if in branch delay slot then the PC already points to
2381 * branch target), and pass the RI exception to the guest OS.
2382 */
2383 vcpu->arch.pc = curr_pc;
2384 return kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
2385 }
2386
2387 enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu,
2388 struct kvm_run *run)
2389 {
2390 unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
2391 enum emulation_result er = EMULATE_DONE;
2392
2393 if (run->mmio.len > sizeof(*gpr)) {
2394 kvm_err("Bad MMIO length: %d", run->mmio.len);
2395 er = EMULATE_FAIL;
2396 goto done;
2397 }
2398
2399 er = update_pc(vcpu, vcpu->arch.pending_load_cause);
2400 if (er == EMULATE_FAIL)
2401 return er;
2402
2403 switch (run->mmio.len) {
2404 case 4:
2405 *gpr = *(int32_t *) run->mmio.data;
2406 break;
2407
2408 case 2:
2409 if (vcpu->mmio_needed == 2)
2410 *gpr = *(int16_t *) run->mmio.data;
2411 else
2412 *gpr = *(uint16_t *)run->mmio.data;
2413
2414 break;
2415 case 1:
2416 if (vcpu->mmio_needed == 2)
2417 *gpr = *(int8_t *) run->mmio.data;
2418 else
2419 *gpr = *(u8 *) run->mmio.data;
2420 break;
2421 }
2422
2423 if (vcpu->arch.pending_load_cause & CAUSEF_BD)
2424 kvm_debug("[%#lx] Completing %d byte BD Load to gpr %d (0x%08lx) type %d\n",
2425 vcpu->arch.pc, run->mmio.len, vcpu->arch.io_gpr, *gpr,
2426 vcpu->mmio_needed);
2427
2428 done:
2429 return er;
2430 }
2431
2432 static enum emulation_result kvm_mips_emulate_exc(unsigned long cause,
2433 uint32_t *opc,
2434 struct kvm_run *run,
2435 struct kvm_vcpu *vcpu)
2436 {
2437 uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2438 struct mips_coproc *cop0 = vcpu->arch.cop0;
2439 struct kvm_vcpu_arch *arch = &vcpu->arch;
2440 enum emulation_result er = EMULATE_DONE;
2441
2442 if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2443 /* save old pc */
2444 kvm_write_c0_guest_epc(cop0, arch->pc);
2445 kvm_set_c0_guest_status(cop0, ST0_EXL);
2446
2447 if (cause & CAUSEF_BD)
2448 kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2449 else
2450 kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2451
2452 kvm_change_c0_guest_cause(cop0, (0xff),
2453 (exccode << CAUSEB_EXCCODE));
2454
2455 /* Set PC to the exception entry point */
2456 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2457 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2458
2459 kvm_debug("Delivering EXC %d @ pc %#lx, badVaddr: %#lx\n",
2460 exccode, kvm_read_c0_guest_epc(cop0),
2461 kvm_read_c0_guest_badvaddr(cop0));
2462 } else {
2463 kvm_err("Trying to deliver EXC when EXL is already set\n");
2464 er = EMULATE_FAIL;
2465 }
2466
2467 return er;
2468 }
2469
2470 enum emulation_result kvm_mips_check_privilege(unsigned long cause,
2471 uint32_t *opc,
2472 struct kvm_run *run,
2473 struct kvm_vcpu *vcpu)
2474 {
2475 enum emulation_result er = EMULATE_DONE;
2476 uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2477 unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
2478
2479 int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
2480
2481 if (usermode) {
2482 switch (exccode) {
2483 case T_INT:
2484 case T_SYSCALL:
2485 case T_BREAK:
2486 case T_RES_INST:
2487 case T_TRAP:
2488 case T_MSAFPE:
2489 case T_FPE:
2490 case T_MSADIS:
2491 break;
2492
2493 case T_COP_UNUSABLE:
2494 if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 0)
2495 er = EMULATE_PRIV_FAIL;
2496 break;
2497
2498 case T_TLB_MOD:
2499 break;
2500
2501 case T_TLB_LD_MISS:
2502 /*
2503 * We we are accessing Guest kernel space, then send an
2504 * address error exception to the guest
2505 */
2506 if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
2507 kvm_debug("%s: LD MISS @ %#lx\n", __func__,
2508 badvaddr);
2509 cause &= ~0xff;
2510 cause |= (T_ADDR_ERR_LD << CAUSEB_EXCCODE);
2511 er = EMULATE_PRIV_FAIL;
2512 }
2513 break;
2514
2515 case T_TLB_ST_MISS:
2516 /*
2517 * We we are accessing Guest kernel space, then send an
2518 * address error exception to the guest
2519 */
2520 if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
2521 kvm_debug("%s: ST MISS @ %#lx\n", __func__,
2522 badvaddr);
2523 cause &= ~0xff;
2524 cause |= (T_ADDR_ERR_ST << CAUSEB_EXCCODE);
2525 er = EMULATE_PRIV_FAIL;
2526 }
2527 break;
2528
2529 case T_ADDR_ERR_ST:
2530 kvm_debug("%s: address error ST @ %#lx\n", __func__,
2531 badvaddr);
2532 if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
2533 cause &= ~0xff;
2534 cause |= (T_TLB_ST_MISS << CAUSEB_EXCCODE);
2535 }
2536 er = EMULATE_PRIV_FAIL;
2537 break;
2538 case T_ADDR_ERR_LD:
2539 kvm_debug("%s: address error LD @ %#lx\n", __func__,
2540 badvaddr);
2541 if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
2542 cause &= ~0xff;
2543 cause |= (T_TLB_LD_MISS << CAUSEB_EXCCODE);
2544 }
2545 er = EMULATE_PRIV_FAIL;
2546 break;
2547 default:
2548 er = EMULATE_PRIV_FAIL;
2549 break;
2550 }
2551 }
2552
2553 if (er == EMULATE_PRIV_FAIL)
2554 kvm_mips_emulate_exc(cause, opc, run, vcpu);
2555
2556 return er;
2557 }
2558
2559 /*
2560 * User Address (UA) fault, this could happen if
2561 * (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this
2562 * case we pass on the fault to the guest kernel and let it handle it.
2563 * (2) TLB entry is present in the Guest TLB but not in the shadow, in this
2564 * case we inject the TLB from the Guest TLB into the shadow host TLB
2565 */
2566 enum emulation_result kvm_mips_handle_tlbmiss(unsigned long cause,
2567 uint32_t *opc,
2568 struct kvm_run *run,
2569 struct kvm_vcpu *vcpu)
2570 {
2571 enum emulation_result er = EMULATE_DONE;
2572 uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2573 unsigned long va = vcpu->arch.host_cp0_badvaddr;
2574 int index;
2575
2576 kvm_debug("kvm_mips_handle_tlbmiss: badvaddr: %#lx, entryhi: %#lx\n",
2577 vcpu->arch.host_cp0_badvaddr, vcpu->arch.host_cp0_entryhi);
2578
2579 /*
2580 * KVM would not have got the exception if this entry was valid in the
2581 * shadow host TLB. Check the Guest TLB, if the entry is not there then
2582 * send the guest an exception. The guest exc handler should then inject
2583 * an entry into the guest TLB.
2584 */
2585 index = kvm_mips_guest_tlb_lookup(vcpu,
2586 (va & VPN2_MASK) |
2587 (kvm_read_c0_guest_entryhi
2588 (vcpu->arch.cop0) & ASID_MASK));
2589 if (index < 0) {
2590 if (exccode == T_TLB_LD_MISS) {
2591 er = kvm_mips_emulate_tlbmiss_ld(cause, opc, run, vcpu);
2592 } else if (exccode == T_TLB_ST_MISS) {
2593 er = kvm_mips_emulate_tlbmiss_st(cause, opc, run, vcpu);
2594 } else {
2595 kvm_err("%s: invalid exc code: %d\n", __func__,
2596 exccode);
2597 er = EMULATE_FAIL;
2598 }
2599 } else {
2600 struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
2601
2602 /*
2603 * Check if the entry is valid, if not then setup a TLB invalid
2604 * exception to the guest
2605 */
2606 if (!TLB_IS_VALID(*tlb, va)) {
2607 if (exccode == T_TLB_LD_MISS) {
2608 er = kvm_mips_emulate_tlbinv_ld(cause, opc, run,
2609 vcpu);
2610 } else if (exccode == T_TLB_ST_MISS) {
2611 er = kvm_mips_emulate_tlbinv_st(cause, opc, run,
2612 vcpu);
2613 } else {
2614 kvm_err("%s: invalid exc code: %d\n", __func__,
2615 exccode);
2616 er = EMULATE_FAIL;
2617 }
2618 } else {
2619 kvm_debug("Injecting hi: %#lx, lo0: %#lx, lo1: %#lx into shadow host TLB\n",
2620 tlb->tlb_hi, tlb->tlb_lo0, tlb->tlb_lo1);
2621 /*
2622 * OK we have a Guest TLB entry, now inject it into the
2623 * shadow host TLB
2624 */
2625 kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, NULL,
2626 NULL);
2627 }
2628 }
2629
2630 return er;
2631 }
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