xref: /openbmc/linux/arch/mips/kvm/mips.c (revision ca55b2fe)
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: MIPS specific KVM APIs
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/kdebug.h>
15 #include <linux/module.h>
16 #include <linux/vmalloc.h>
17 #include <linux/fs.h>
18 #include <linux/bootmem.h>
19 #include <asm/fpu.h>
20 #include <asm/page.h>
21 #include <asm/cacheflush.h>
22 #include <asm/mmu_context.h>
23 #include <asm/pgtable.h>
24 
25 #include <linux/kvm_host.h>
26 
27 #include "interrupt.h"
28 #include "commpage.h"
29 
30 #define CREATE_TRACE_POINTS
31 #include "trace.h"
32 
33 #ifndef VECTORSPACING
34 #define VECTORSPACING 0x100	/* for EI/VI mode */
35 #endif
36 
37 #define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x)
38 struct kvm_stats_debugfs_item debugfs_entries[] = {
39 	{ "wait",	  VCPU_STAT(wait_exits),	 KVM_STAT_VCPU },
40 	{ "cache",	  VCPU_STAT(cache_exits),	 KVM_STAT_VCPU },
41 	{ "signal",	  VCPU_STAT(signal_exits),	 KVM_STAT_VCPU },
42 	{ "interrupt",	  VCPU_STAT(int_exits),		 KVM_STAT_VCPU },
43 	{ "cop_unsuable", VCPU_STAT(cop_unusable_exits), KVM_STAT_VCPU },
44 	{ "tlbmod",	  VCPU_STAT(tlbmod_exits),	 KVM_STAT_VCPU },
45 	{ "tlbmiss_ld",	  VCPU_STAT(tlbmiss_ld_exits),	 KVM_STAT_VCPU },
46 	{ "tlbmiss_st",	  VCPU_STAT(tlbmiss_st_exits),	 KVM_STAT_VCPU },
47 	{ "addrerr_st",	  VCPU_STAT(addrerr_st_exits),	 KVM_STAT_VCPU },
48 	{ "addrerr_ld",	  VCPU_STAT(addrerr_ld_exits),	 KVM_STAT_VCPU },
49 	{ "syscall",	  VCPU_STAT(syscall_exits),	 KVM_STAT_VCPU },
50 	{ "resvd_inst",	  VCPU_STAT(resvd_inst_exits),	 KVM_STAT_VCPU },
51 	{ "break_inst",	  VCPU_STAT(break_inst_exits),	 KVM_STAT_VCPU },
52 	{ "trap_inst",	  VCPU_STAT(trap_inst_exits),	 KVM_STAT_VCPU },
53 	{ "msa_fpe",	  VCPU_STAT(msa_fpe_exits),	 KVM_STAT_VCPU },
54 	{ "fpe",	  VCPU_STAT(fpe_exits),		 KVM_STAT_VCPU },
55 	{ "msa_disabled", VCPU_STAT(msa_disabled_exits), KVM_STAT_VCPU },
56 	{ "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU },
57 	{ "halt_successful_poll", VCPU_STAT(halt_successful_poll), KVM_STAT_VCPU },
58 	{ "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), KVM_STAT_VCPU },
59 	{ "halt_wakeup",  VCPU_STAT(halt_wakeup),	 KVM_STAT_VCPU },
60 	{NULL}
61 };
62 
63 static int kvm_mips_reset_vcpu(struct kvm_vcpu *vcpu)
64 {
65 	int i;
66 
67 	for_each_possible_cpu(i) {
68 		vcpu->arch.guest_kernel_asid[i] = 0;
69 		vcpu->arch.guest_user_asid[i] = 0;
70 	}
71 
72 	return 0;
73 }
74 
75 /*
76  * XXXKYMA: We are simulatoring a processor that has the WII bit set in
77  * Config7, so we are "runnable" if interrupts are pending
78  */
79 int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
80 {
81 	return !!(vcpu->arch.pending_exceptions);
82 }
83 
84 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
85 {
86 	return 1;
87 }
88 
89 int kvm_arch_hardware_enable(void)
90 {
91 	return 0;
92 }
93 
94 int kvm_arch_hardware_setup(void)
95 {
96 	return 0;
97 }
98 
99 void kvm_arch_check_processor_compat(void *rtn)
100 {
101 	*(int *)rtn = 0;
102 }
103 
104 static void kvm_mips_init_tlbs(struct kvm *kvm)
105 {
106 	unsigned long wired;
107 
108 	/*
109 	 * Add a wired entry to the TLB, it is used to map the commpage to
110 	 * the Guest kernel
111 	 */
112 	wired = read_c0_wired();
113 	write_c0_wired(wired + 1);
114 	mtc0_tlbw_hazard();
115 	kvm->arch.commpage_tlb = wired;
116 
117 	kvm_debug("[%d] commpage TLB: %d\n", smp_processor_id(),
118 		  kvm->arch.commpage_tlb);
119 }
120 
121 static void kvm_mips_init_vm_percpu(void *arg)
122 {
123 	struct kvm *kvm = (struct kvm *)arg;
124 
125 	kvm_mips_init_tlbs(kvm);
126 	kvm_mips_callbacks->vm_init(kvm);
127 
128 }
129 
130 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
131 {
132 	if (atomic_inc_return(&kvm_mips_instance) == 1) {
133 		kvm_debug("%s: 1st KVM instance, setup host TLB parameters\n",
134 			  __func__);
135 		on_each_cpu(kvm_mips_init_vm_percpu, kvm, 1);
136 	}
137 
138 	return 0;
139 }
140 
141 void kvm_mips_free_vcpus(struct kvm *kvm)
142 {
143 	unsigned int i;
144 	struct kvm_vcpu *vcpu;
145 
146 	/* Put the pages we reserved for the guest pmap */
147 	for (i = 0; i < kvm->arch.guest_pmap_npages; i++) {
148 		if (kvm->arch.guest_pmap[i] != KVM_INVALID_PAGE)
149 			kvm_mips_release_pfn_clean(kvm->arch.guest_pmap[i]);
150 	}
151 	kfree(kvm->arch.guest_pmap);
152 
153 	kvm_for_each_vcpu(i, vcpu, kvm) {
154 		kvm_arch_vcpu_free(vcpu);
155 	}
156 
157 	mutex_lock(&kvm->lock);
158 
159 	for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
160 		kvm->vcpus[i] = NULL;
161 
162 	atomic_set(&kvm->online_vcpus, 0);
163 
164 	mutex_unlock(&kvm->lock);
165 }
166 
167 static void kvm_mips_uninit_tlbs(void *arg)
168 {
169 	/* Restore wired count */
170 	write_c0_wired(0);
171 	mtc0_tlbw_hazard();
172 	/* Clear out all the TLBs */
173 	kvm_local_flush_tlb_all();
174 }
175 
176 void kvm_arch_destroy_vm(struct kvm *kvm)
177 {
178 	kvm_mips_free_vcpus(kvm);
179 
180 	/* If this is the last instance, restore wired count */
181 	if (atomic_dec_return(&kvm_mips_instance) == 0) {
182 		kvm_debug("%s: last KVM instance, restoring TLB parameters\n",
183 			  __func__);
184 		on_each_cpu(kvm_mips_uninit_tlbs, NULL, 1);
185 	}
186 }
187 
188 long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl,
189 			unsigned long arg)
190 {
191 	return -ENOIOCTLCMD;
192 }
193 
194 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
195 			    unsigned long npages)
196 {
197 	return 0;
198 }
199 
200 int kvm_arch_prepare_memory_region(struct kvm *kvm,
201 				   struct kvm_memory_slot *memslot,
202 				   const struct kvm_userspace_memory_region *mem,
203 				   enum kvm_mr_change change)
204 {
205 	return 0;
206 }
207 
208 void kvm_arch_commit_memory_region(struct kvm *kvm,
209 				   const struct kvm_userspace_memory_region *mem,
210 				   const struct kvm_memory_slot *old,
211 				   const struct kvm_memory_slot *new,
212 				   enum kvm_mr_change change)
213 {
214 	unsigned long npages = 0;
215 	int i;
216 
217 	kvm_debug("%s: kvm: %p slot: %d, GPA: %llx, size: %llx, QVA: %llx\n",
218 		  __func__, kvm, mem->slot, mem->guest_phys_addr,
219 		  mem->memory_size, mem->userspace_addr);
220 
221 	/* Setup Guest PMAP table */
222 	if (!kvm->arch.guest_pmap) {
223 		if (mem->slot == 0)
224 			npages = mem->memory_size >> PAGE_SHIFT;
225 
226 		if (npages) {
227 			kvm->arch.guest_pmap_npages = npages;
228 			kvm->arch.guest_pmap =
229 			    kzalloc(npages * sizeof(unsigned long), GFP_KERNEL);
230 
231 			if (!kvm->arch.guest_pmap) {
232 				kvm_err("Failed to allocate guest PMAP");
233 				return;
234 			}
235 
236 			kvm_debug("Allocated space for Guest PMAP Table (%ld pages) @ %p\n",
237 				  npages, kvm->arch.guest_pmap);
238 
239 			/* Now setup the page table */
240 			for (i = 0; i < npages; i++)
241 				kvm->arch.guest_pmap[i] = KVM_INVALID_PAGE;
242 		}
243 	}
244 }
245 
246 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
247 {
248 	int err, size, offset;
249 	void *gebase;
250 	int i;
251 
252 	struct kvm_vcpu *vcpu = kzalloc(sizeof(struct kvm_vcpu), GFP_KERNEL);
253 
254 	if (!vcpu) {
255 		err = -ENOMEM;
256 		goto out;
257 	}
258 
259 	err = kvm_vcpu_init(vcpu, kvm, id);
260 
261 	if (err)
262 		goto out_free_cpu;
263 
264 	kvm_debug("kvm @ %p: create cpu %d at %p\n", kvm, id, vcpu);
265 
266 	/*
267 	 * Allocate space for host mode exception handlers that handle
268 	 * guest mode exits
269 	 */
270 	if (cpu_has_veic || cpu_has_vint)
271 		size = 0x200 + VECTORSPACING * 64;
272 	else
273 		size = 0x4000;
274 
275 	/* Save Linux EBASE */
276 	vcpu->arch.host_ebase = (void *)read_c0_ebase();
277 
278 	gebase = kzalloc(ALIGN(size, PAGE_SIZE), GFP_KERNEL);
279 
280 	if (!gebase) {
281 		err = -ENOMEM;
282 		goto out_free_cpu;
283 	}
284 	kvm_debug("Allocated %d bytes for KVM Exception Handlers @ %p\n",
285 		  ALIGN(size, PAGE_SIZE), gebase);
286 
287 	/* Save new ebase */
288 	vcpu->arch.guest_ebase = gebase;
289 
290 	/* Copy L1 Guest Exception handler to correct offset */
291 
292 	/* TLB Refill, EXL = 0 */
293 	memcpy(gebase, mips32_exception,
294 	       mips32_exceptionEnd - mips32_exception);
295 
296 	/* General Exception Entry point */
297 	memcpy(gebase + 0x180, mips32_exception,
298 	       mips32_exceptionEnd - mips32_exception);
299 
300 	/* For vectored interrupts poke the exception code @ all offsets 0-7 */
301 	for (i = 0; i < 8; i++) {
302 		kvm_debug("L1 Vectored handler @ %p\n",
303 			  gebase + 0x200 + (i * VECTORSPACING));
304 		memcpy(gebase + 0x200 + (i * VECTORSPACING), mips32_exception,
305 		       mips32_exceptionEnd - mips32_exception);
306 	}
307 
308 	/* General handler, relocate to unmapped space for sanity's sake */
309 	offset = 0x2000;
310 	kvm_debug("Installing KVM Exception handlers @ %p, %#x bytes\n",
311 		  gebase + offset,
312 		  mips32_GuestExceptionEnd - mips32_GuestException);
313 
314 	memcpy(gebase + offset, mips32_GuestException,
315 	       mips32_GuestExceptionEnd - mips32_GuestException);
316 
317 	/* Invalidate the icache for these ranges */
318 	local_flush_icache_range((unsigned long)gebase,
319 				(unsigned long)gebase + ALIGN(size, PAGE_SIZE));
320 
321 	/*
322 	 * Allocate comm page for guest kernel, a TLB will be reserved for
323 	 * mapping GVA @ 0xFFFF8000 to this page
324 	 */
325 	vcpu->arch.kseg0_commpage = kzalloc(PAGE_SIZE << 1, GFP_KERNEL);
326 
327 	if (!vcpu->arch.kseg0_commpage) {
328 		err = -ENOMEM;
329 		goto out_free_gebase;
330 	}
331 
332 	kvm_debug("Allocated COMM page @ %p\n", vcpu->arch.kseg0_commpage);
333 	kvm_mips_commpage_init(vcpu);
334 
335 	/* Init */
336 	vcpu->arch.last_sched_cpu = -1;
337 
338 	/* Start off the timer */
339 	kvm_mips_init_count(vcpu);
340 
341 	return vcpu;
342 
343 out_free_gebase:
344 	kfree(gebase);
345 
346 out_free_cpu:
347 	kfree(vcpu);
348 
349 out:
350 	return ERR_PTR(err);
351 }
352 
353 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
354 {
355 	hrtimer_cancel(&vcpu->arch.comparecount_timer);
356 
357 	kvm_vcpu_uninit(vcpu);
358 
359 	kvm_mips_dump_stats(vcpu);
360 
361 	kfree(vcpu->arch.guest_ebase);
362 	kfree(vcpu->arch.kseg0_commpage);
363 	kfree(vcpu);
364 }
365 
366 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
367 {
368 	kvm_arch_vcpu_free(vcpu);
369 }
370 
371 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
372 					struct kvm_guest_debug *dbg)
373 {
374 	return -ENOIOCTLCMD;
375 }
376 
377 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
378 {
379 	int r = 0;
380 	sigset_t sigsaved;
381 
382 	if (vcpu->sigset_active)
383 		sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
384 
385 	if (vcpu->mmio_needed) {
386 		if (!vcpu->mmio_is_write)
387 			kvm_mips_complete_mmio_load(vcpu, run);
388 		vcpu->mmio_needed = 0;
389 	}
390 
391 	lose_fpu(1);
392 
393 	local_irq_disable();
394 	/* Check if we have any exceptions/interrupts pending */
395 	kvm_mips_deliver_interrupts(vcpu,
396 				    kvm_read_c0_guest_cause(vcpu->arch.cop0));
397 
398 	__kvm_guest_enter();
399 
400 	/* Disable hardware page table walking while in guest */
401 	htw_stop();
402 
403 	r = __kvm_mips_vcpu_run(run, vcpu);
404 
405 	/* Re-enable HTW before enabling interrupts */
406 	htw_start();
407 
408 	__kvm_guest_exit();
409 	local_irq_enable();
410 
411 	if (vcpu->sigset_active)
412 		sigprocmask(SIG_SETMASK, &sigsaved, NULL);
413 
414 	return r;
415 }
416 
417 int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
418 			     struct kvm_mips_interrupt *irq)
419 {
420 	int intr = (int)irq->irq;
421 	struct kvm_vcpu *dvcpu = NULL;
422 
423 	if (intr == 3 || intr == -3 || intr == 4 || intr == -4)
424 		kvm_debug("%s: CPU: %d, INTR: %d\n", __func__, irq->cpu,
425 			  (int)intr);
426 
427 	if (irq->cpu == -1)
428 		dvcpu = vcpu;
429 	else
430 		dvcpu = vcpu->kvm->vcpus[irq->cpu];
431 
432 	if (intr == 2 || intr == 3 || intr == 4) {
433 		kvm_mips_callbacks->queue_io_int(dvcpu, irq);
434 
435 	} else if (intr == -2 || intr == -3 || intr == -4) {
436 		kvm_mips_callbacks->dequeue_io_int(dvcpu, irq);
437 	} else {
438 		kvm_err("%s: invalid interrupt ioctl (%d:%d)\n", __func__,
439 			irq->cpu, irq->irq);
440 		return -EINVAL;
441 	}
442 
443 	dvcpu->arch.wait = 0;
444 
445 	if (waitqueue_active(&dvcpu->wq))
446 		wake_up_interruptible(&dvcpu->wq);
447 
448 	return 0;
449 }
450 
451 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
452 				    struct kvm_mp_state *mp_state)
453 {
454 	return -ENOIOCTLCMD;
455 }
456 
457 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
458 				    struct kvm_mp_state *mp_state)
459 {
460 	return -ENOIOCTLCMD;
461 }
462 
463 static u64 kvm_mips_get_one_regs[] = {
464 	KVM_REG_MIPS_R0,
465 	KVM_REG_MIPS_R1,
466 	KVM_REG_MIPS_R2,
467 	KVM_REG_MIPS_R3,
468 	KVM_REG_MIPS_R4,
469 	KVM_REG_MIPS_R5,
470 	KVM_REG_MIPS_R6,
471 	KVM_REG_MIPS_R7,
472 	KVM_REG_MIPS_R8,
473 	KVM_REG_MIPS_R9,
474 	KVM_REG_MIPS_R10,
475 	KVM_REG_MIPS_R11,
476 	KVM_REG_MIPS_R12,
477 	KVM_REG_MIPS_R13,
478 	KVM_REG_MIPS_R14,
479 	KVM_REG_MIPS_R15,
480 	KVM_REG_MIPS_R16,
481 	KVM_REG_MIPS_R17,
482 	KVM_REG_MIPS_R18,
483 	KVM_REG_MIPS_R19,
484 	KVM_REG_MIPS_R20,
485 	KVM_REG_MIPS_R21,
486 	KVM_REG_MIPS_R22,
487 	KVM_REG_MIPS_R23,
488 	KVM_REG_MIPS_R24,
489 	KVM_REG_MIPS_R25,
490 	KVM_REG_MIPS_R26,
491 	KVM_REG_MIPS_R27,
492 	KVM_REG_MIPS_R28,
493 	KVM_REG_MIPS_R29,
494 	KVM_REG_MIPS_R30,
495 	KVM_REG_MIPS_R31,
496 
497 	KVM_REG_MIPS_HI,
498 	KVM_REG_MIPS_LO,
499 	KVM_REG_MIPS_PC,
500 
501 	KVM_REG_MIPS_CP0_INDEX,
502 	KVM_REG_MIPS_CP0_CONTEXT,
503 	KVM_REG_MIPS_CP0_USERLOCAL,
504 	KVM_REG_MIPS_CP0_PAGEMASK,
505 	KVM_REG_MIPS_CP0_WIRED,
506 	KVM_REG_MIPS_CP0_HWRENA,
507 	KVM_REG_MIPS_CP0_BADVADDR,
508 	KVM_REG_MIPS_CP0_COUNT,
509 	KVM_REG_MIPS_CP0_ENTRYHI,
510 	KVM_REG_MIPS_CP0_COMPARE,
511 	KVM_REG_MIPS_CP0_STATUS,
512 	KVM_REG_MIPS_CP0_CAUSE,
513 	KVM_REG_MIPS_CP0_EPC,
514 	KVM_REG_MIPS_CP0_PRID,
515 	KVM_REG_MIPS_CP0_CONFIG,
516 	KVM_REG_MIPS_CP0_CONFIG1,
517 	KVM_REG_MIPS_CP0_CONFIG2,
518 	KVM_REG_MIPS_CP0_CONFIG3,
519 	KVM_REG_MIPS_CP0_CONFIG4,
520 	KVM_REG_MIPS_CP0_CONFIG5,
521 	KVM_REG_MIPS_CP0_CONFIG7,
522 	KVM_REG_MIPS_CP0_ERROREPC,
523 
524 	KVM_REG_MIPS_COUNT_CTL,
525 	KVM_REG_MIPS_COUNT_RESUME,
526 	KVM_REG_MIPS_COUNT_HZ,
527 };
528 
529 static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
530 			    const struct kvm_one_reg *reg)
531 {
532 	struct mips_coproc *cop0 = vcpu->arch.cop0;
533 	struct mips_fpu_struct *fpu = &vcpu->arch.fpu;
534 	int ret;
535 	s64 v;
536 	s64 vs[2];
537 	unsigned int idx;
538 
539 	switch (reg->id) {
540 	/* General purpose registers */
541 	case KVM_REG_MIPS_R0 ... KVM_REG_MIPS_R31:
542 		v = (long)vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0];
543 		break;
544 	case KVM_REG_MIPS_HI:
545 		v = (long)vcpu->arch.hi;
546 		break;
547 	case KVM_REG_MIPS_LO:
548 		v = (long)vcpu->arch.lo;
549 		break;
550 	case KVM_REG_MIPS_PC:
551 		v = (long)vcpu->arch.pc;
552 		break;
553 
554 	/* Floating point registers */
555 	case KVM_REG_MIPS_FPR_32(0) ... KVM_REG_MIPS_FPR_32(31):
556 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
557 			return -EINVAL;
558 		idx = reg->id - KVM_REG_MIPS_FPR_32(0);
559 		/* Odd singles in top of even double when FR=0 */
560 		if (kvm_read_c0_guest_status(cop0) & ST0_FR)
561 			v = get_fpr32(&fpu->fpr[idx], 0);
562 		else
563 			v = get_fpr32(&fpu->fpr[idx & ~1], idx & 1);
564 		break;
565 	case KVM_REG_MIPS_FPR_64(0) ... KVM_REG_MIPS_FPR_64(31):
566 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
567 			return -EINVAL;
568 		idx = reg->id - KVM_REG_MIPS_FPR_64(0);
569 		/* Can't access odd doubles in FR=0 mode */
570 		if (idx & 1 && !(kvm_read_c0_guest_status(cop0) & ST0_FR))
571 			return -EINVAL;
572 		v = get_fpr64(&fpu->fpr[idx], 0);
573 		break;
574 	case KVM_REG_MIPS_FCR_IR:
575 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
576 			return -EINVAL;
577 		v = boot_cpu_data.fpu_id;
578 		break;
579 	case KVM_REG_MIPS_FCR_CSR:
580 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
581 			return -EINVAL;
582 		v = fpu->fcr31;
583 		break;
584 
585 	/* MIPS SIMD Architecture (MSA) registers */
586 	case KVM_REG_MIPS_VEC_128(0) ... KVM_REG_MIPS_VEC_128(31):
587 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
588 			return -EINVAL;
589 		/* Can't access MSA registers in FR=0 mode */
590 		if (!(kvm_read_c0_guest_status(cop0) & ST0_FR))
591 			return -EINVAL;
592 		idx = reg->id - KVM_REG_MIPS_VEC_128(0);
593 #ifdef CONFIG_CPU_LITTLE_ENDIAN
594 		/* least significant byte first */
595 		vs[0] = get_fpr64(&fpu->fpr[idx], 0);
596 		vs[1] = get_fpr64(&fpu->fpr[idx], 1);
597 #else
598 		/* most significant byte first */
599 		vs[0] = get_fpr64(&fpu->fpr[idx], 1);
600 		vs[1] = get_fpr64(&fpu->fpr[idx], 0);
601 #endif
602 		break;
603 	case KVM_REG_MIPS_MSA_IR:
604 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
605 			return -EINVAL;
606 		v = boot_cpu_data.msa_id;
607 		break;
608 	case KVM_REG_MIPS_MSA_CSR:
609 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
610 			return -EINVAL;
611 		v = fpu->msacsr;
612 		break;
613 
614 	/* Co-processor 0 registers */
615 	case KVM_REG_MIPS_CP0_INDEX:
616 		v = (long)kvm_read_c0_guest_index(cop0);
617 		break;
618 	case KVM_REG_MIPS_CP0_CONTEXT:
619 		v = (long)kvm_read_c0_guest_context(cop0);
620 		break;
621 	case KVM_REG_MIPS_CP0_USERLOCAL:
622 		v = (long)kvm_read_c0_guest_userlocal(cop0);
623 		break;
624 	case KVM_REG_MIPS_CP0_PAGEMASK:
625 		v = (long)kvm_read_c0_guest_pagemask(cop0);
626 		break;
627 	case KVM_REG_MIPS_CP0_WIRED:
628 		v = (long)kvm_read_c0_guest_wired(cop0);
629 		break;
630 	case KVM_REG_MIPS_CP0_HWRENA:
631 		v = (long)kvm_read_c0_guest_hwrena(cop0);
632 		break;
633 	case KVM_REG_MIPS_CP0_BADVADDR:
634 		v = (long)kvm_read_c0_guest_badvaddr(cop0);
635 		break;
636 	case KVM_REG_MIPS_CP0_ENTRYHI:
637 		v = (long)kvm_read_c0_guest_entryhi(cop0);
638 		break;
639 	case KVM_REG_MIPS_CP0_COMPARE:
640 		v = (long)kvm_read_c0_guest_compare(cop0);
641 		break;
642 	case KVM_REG_MIPS_CP0_STATUS:
643 		v = (long)kvm_read_c0_guest_status(cop0);
644 		break;
645 	case KVM_REG_MIPS_CP0_CAUSE:
646 		v = (long)kvm_read_c0_guest_cause(cop0);
647 		break;
648 	case KVM_REG_MIPS_CP0_EPC:
649 		v = (long)kvm_read_c0_guest_epc(cop0);
650 		break;
651 	case KVM_REG_MIPS_CP0_PRID:
652 		v = (long)kvm_read_c0_guest_prid(cop0);
653 		break;
654 	case KVM_REG_MIPS_CP0_CONFIG:
655 		v = (long)kvm_read_c0_guest_config(cop0);
656 		break;
657 	case KVM_REG_MIPS_CP0_CONFIG1:
658 		v = (long)kvm_read_c0_guest_config1(cop0);
659 		break;
660 	case KVM_REG_MIPS_CP0_CONFIG2:
661 		v = (long)kvm_read_c0_guest_config2(cop0);
662 		break;
663 	case KVM_REG_MIPS_CP0_CONFIG3:
664 		v = (long)kvm_read_c0_guest_config3(cop0);
665 		break;
666 	case KVM_REG_MIPS_CP0_CONFIG4:
667 		v = (long)kvm_read_c0_guest_config4(cop0);
668 		break;
669 	case KVM_REG_MIPS_CP0_CONFIG5:
670 		v = (long)kvm_read_c0_guest_config5(cop0);
671 		break;
672 	case KVM_REG_MIPS_CP0_CONFIG7:
673 		v = (long)kvm_read_c0_guest_config7(cop0);
674 		break;
675 	case KVM_REG_MIPS_CP0_ERROREPC:
676 		v = (long)kvm_read_c0_guest_errorepc(cop0);
677 		break;
678 	/* registers to be handled specially */
679 	case KVM_REG_MIPS_CP0_COUNT:
680 	case KVM_REG_MIPS_COUNT_CTL:
681 	case KVM_REG_MIPS_COUNT_RESUME:
682 	case KVM_REG_MIPS_COUNT_HZ:
683 		ret = kvm_mips_callbacks->get_one_reg(vcpu, reg, &v);
684 		if (ret)
685 			return ret;
686 		break;
687 	default:
688 		return -EINVAL;
689 	}
690 	if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U64) {
691 		u64 __user *uaddr64 = (u64 __user *)(long)reg->addr;
692 
693 		return put_user(v, uaddr64);
694 	} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U32) {
695 		u32 __user *uaddr32 = (u32 __user *)(long)reg->addr;
696 		u32 v32 = (u32)v;
697 
698 		return put_user(v32, uaddr32);
699 	} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) {
700 		void __user *uaddr = (void __user *)(long)reg->addr;
701 
702 		return copy_to_user(uaddr, vs, 16);
703 	} else {
704 		return -EINVAL;
705 	}
706 }
707 
708 static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
709 			    const struct kvm_one_reg *reg)
710 {
711 	struct mips_coproc *cop0 = vcpu->arch.cop0;
712 	struct mips_fpu_struct *fpu = &vcpu->arch.fpu;
713 	s64 v;
714 	s64 vs[2];
715 	unsigned int idx;
716 
717 	if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U64) {
718 		u64 __user *uaddr64 = (u64 __user *)(long)reg->addr;
719 
720 		if (get_user(v, uaddr64) != 0)
721 			return -EFAULT;
722 	} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U32) {
723 		u32 __user *uaddr32 = (u32 __user *)(long)reg->addr;
724 		s32 v32;
725 
726 		if (get_user(v32, uaddr32) != 0)
727 			return -EFAULT;
728 		v = (s64)v32;
729 	} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) {
730 		void __user *uaddr = (void __user *)(long)reg->addr;
731 
732 		return copy_from_user(vs, uaddr, 16);
733 	} else {
734 		return -EINVAL;
735 	}
736 
737 	switch (reg->id) {
738 	/* General purpose registers */
739 	case KVM_REG_MIPS_R0:
740 		/* Silently ignore requests to set $0 */
741 		break;
742 	case KVM_REG_MIPS_R1 ... KVM_REG_MIPS_R31:
743 		vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0] = v;
744 		break;
745 	case KVM_REG_MIPS_HI:
746 		vcpu->arch.hi = v;
747 		break;
748 	case KVM_REG_MIPS_LO:
749 		vcpu->arch.lo = v;
750 		break;
751 	case KVM_REG_MIPS_PC:
752 		vcpu->arch.pc = v;
753 		break;
754 
755 	/* Floating point registers */
756 	case KVM_REG_MIPS_FPR_32(0) ... KVM_REG_MIPS_FPR_32(31):
757 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
758 			return -EINVAL;
759 		idx = reg->id - KVM_REG_MIPS_FPR_32(0);
760 		/* Odd singles in top of even double when FR=0 */
761 		if (kvm_read_c0_guest_status(cop0) & ST0_FR)
762 			set_fpr32(&fpu->fpr[idx], 0, v);
763 		else
764 			set_fpr32(&fpu->fpr[idx & ~1], idx & 1, v);
765 		break;
766 	case KVM_REG_MIPS_FPR_64(0) ... KVM_REG_MIPS_FPR_64(31):
767 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
768 			return -EINVAL;
769 		idx = reg->id - KVM_REG_MIPS_FPR_64(0);
770 		/* Can't access odd doubles in FR=0 mode */
771 		if (idx & 1 && !(kvm_read_c0_guest_status(cop0) & ST0_FR))
772 			return -EINVAL;
773 		set_fpr64(&fpu->fpr[idx], 0, v);
774 		break;
775 	case KVM_REG_MIPS_FCR_IR:
776 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
777 			return -EINVAL;
778 		/* Read-only */
779 		break;
780 	case KVM_REG_MIPS_FCR_CSR:
781 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
782 			return -EINVAL;
783 		fpu->fcr31 = v;
784 		break;
785 
786 	/* MIPS SIMD Architecture (MSA) registers */
787 	case KVM_REG_MIPS_VEC_128(0) ... KVM_REG_MIPS_VEC_128(31):
788 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
789 			return -EINVAL;
790 		idx = reg->id - KVM_REG_MIPS_VEC_128(0);
791 #ifdef CONFIG_CPU_LITTLE_ENDIAN
792 		/* least significant byte first */
793 		set_fpr64(&fpu->fpr[idx], 0, vs[0]);
794 		set_fpr64(&fpu->fpr[idx], 1, vs[1]);
795 #else
796 		/* most significant byte first */
797 		set_fpr64(&fpu->fpr[idx], 1, vs[0]);
798 		set_fpr64(&fpu->fpr[idx], 0, vs[1]);
799 #endif
800 		break;
801 	case KVM_REG_MIPS_MSA_IR:
802 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
803 			return -EINVAL;
804 		/* Read-only */
805 		break;
806 	case KVM_REG_MIPS_MSA_CSR:
807 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
808 			return -EINVAL;
809 		fpu->msacsr = v;
810 		break;
811 
812 	/* Co-processor 0 registers */
813 	case KVM_REG_MIPS_CP0_INDEX:
814 		kvm_write_c0_guest_index(cop0, v);
815 		break;
816 	case KVM_REG_MIPS_CP0_CONTEXT:
817 		kvm_write_c0_guest_context(cop0, v);
818 		break;
819 	case KVM_REG_MIPS_CP0_USERLOCAL:
820 		kvm_write_c0_guest_userlocal(cop0, v);
821 		break;
822 	case KVM_REG_MIPS_CP0_PAGEMASK:
823 		kvm_write_c0_guest_pagemask(cop0, v);
824 		break;
825 	case KVM_REG_MIPS_CP0_WIRED:
826 		kvm_write_c0_guest_wired(cop0, v);
827 		break;
828 	case KVM_REG_MIPS_CP0_HWRENA:
829 		kvm_write_c0_guest_hwrena(cop0, v);
830 		break;
831 	case KVM_REG_MIPS_CP0_BADVADDR:
832 		kvm_write_c0_guest_badvaddr(cop0, v);
833 		break;
834 	case KVM_REG_MIPS_CP0_ENTRYHI:
835 		kvm_write_c0_guest_entryhi(cop0, v);
836 		break;
837 	case KVM_REG_MIPS_CP0_STATUS:
838 		kvm_write_c0_guest_status(cop0, v);
839 		break;
840 	case KVM_REG_MIPS_CP0_EPC:
841 		kvm_write_c0_guest_epc(cop0, v);
842 		break;
843 	case KVM_REG_MIPS_CP0_PRID:
844 		kvm_write_c0_guest_prid(cop0, v);
845 		break;
846 	case KVM_REG_MIPS_CP0_ERROREPC:
847 		kvm_write_c0_guest_errorepc(cop0, v);
848 		break;
849 	/* registers to be handled specially */
850 	case KVM_REG_MIPS_CP0_COUNT:
851 	case KVM_REG_MIPS_CP0_COMPARE:
852 	case KVM_REG_MIPS_CP0_CAUSE:
853 	case KVM_REG_MIPS_CP0_CONFIG:
854 	case KVM_REG_MIPS_CP0_CONFIG1:
855 	case KVM_REG_MIPS_CP0_CONFIG2:
856 	case KVM_REG_MIPS_CP0_CONFIG3:
857 	case KVM_REG_MIPS_CP0_CONFIG4:
858 	case KVM_REG_MIPS_CP0_CONFIG5:
859 	case KVM_REG_MIPS_COUNT_CTL:
860 	case KVM_REG_MIPS_COUNT_RESUME:
861 	case KVM_REG_MIPS_COUNT_HZ:
862 		return kvm_mips_callbacks->set_one_reg(vcpu, reg, v);
863 	default:
864 		return -EINVAL;
865 	}
866 	return 0;
867 }
868 
869 static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
870 				     struct kvm_enable_cap *cap)
871 {
872 	int r = 0;
873 
874 	if (!kvm_vm_ioctl_check_extension(vcpu->kvm, cap->cap))
875 		return -EINVAL;
876 	if (cap->flags)
877 		return -EINVAL;
878 	if (cap->args[0])
879 		return -EINVAL;
880 
881 	switch (cap->cap) {
882 	case KVM_CAP_MIPS_FPU:
883 		vcpu->arch.fpu_enabled = true;
884 		break;
885 	case KVM_CAP_MIPS_MSA:
886 		vcpu->arch.msa_enabled = true;
887 		break;
888 	default:
889 		r = -EINVAL;
890 		break;
891 	}
892 
893 	return r;
894 }
895 
896 long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl,
897 			 unsigned long arg)
898 {
899 	struct kvm_vcpu *vcpu = filp->private_data;
900 	void __user *argp = (void __user *)arg;
901 	long r;
902 
903 	switch (ioctl) {
904 	case KVM_SET_ONE_REG:
905 	case KVM_GET_ONE_REG: {
906 		struct kvm_one_reg reg;
907 
908 		if (copy_from_user(&reg, argp, sizeof(reg)))
909 			return -EFAULT;
910 		if (ioctl == KVM_SET_ONE_REG)
911 			return kvm_mips_set_reg(vcpu, &reg);
912 		else
913 			return kvm_mips_get_reg(vcpu, &reg);
914 	}
915 	case KVM_GET_REG_LIST: {
916 		struct kvm_reg_list __user *user_list = argp;
917 		u64 __user *reg_dest;
918 		struct kvm_reg_list reg_list;
919 		unsigned n;
920 
921 		if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
922 			return -EFAULT;
923 		n = reg_list.n;
924 		reg_list.n = ARRAY_SIZE(kvm_mips_get_one_regs);
925 		if (copy_to_user(user_list, &reg_list, sizeof(reg_list)))
926 			return -EFAULT;
927 		if (n < reg_list.n)
928 			return -E2BIG;
929 		reg_dest = user_list->reg;
930 		if (copy_to_user(reg_dest, kvm_mips_get_one_regs,
931 				 sizeof(kvm_mips_get_one_regs)))
932 			return -EFAULT;
933 		return 0;
934 	}
935 	case KVM_NMI:
936 		/* Treat the NMI as a CPU reset */
937 		r = kvm_mips_reset_vcpu(vcpu);
938 		break;
939 	case KVM_INTERRUPT:
940 		{
941 			struct kvm_mips_interrupt irq;
942 
943 			r = -EFAULT;
944 			if (copy_from_user(&irq, argp, sizeof(irq)))
945 				goto out;
946 
947 			kvm_debug("[%d] %s: irq: %d\n", vcpu->vcpu_id, __func__,
948 				  irq.irq);
949 
950 			r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
951 			break;
952 		}
953 	case KVM_ENABLE_CAP: {
954 		struct kvm_enable_cap cap;
955 
956 		r = -EFAULT;
957 		if (copy_from_user(&cap, argp, sizeof(cap)))
958 			goto out;
959 		r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
960 		break;
961 	}
962 	default:
963 		r = -ENOIOCTLCMD;
964 	}
965 
966 out:
967 	return r;
968 }
969 
970 /* Get (and clear) the dirty memory log for a memory slot. */
971 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
972 {
973 	struct kvm_memslots *slots;
974 	struct kvm_memory_slot *memslot;
975 	unsigned long ga, ga_end;
976 	int is_dirty = 0;
977 	int r;
978 	unsigned long n;
979 
980 	mutex_lock(&kvm->slots_lock);
981 
982 	r = kvm_get_dirty_log(kvm, log, &is_dirty);
983 	if (r)
984 		goto out;
985 
986 	/* If nothing is dirty, don't bother messing with page tables. */
987 	if (is_dirty) {
988 		slots = kvm_memslots(kvm);
989 		memslot = id_to_memslot(slots, log->slot);
990 
991 		ga = memslot->base_gfn << PAGE_SHIFT;
992 		ga_end = ga + (memslot->npages << PAGE_SHIFT);
993 
994 		kvm_info("%s: dirty, ga: %#lx, ga_end %#lx\n", __func__, ga,
995 			 ga_end);
996 
997 		n = kvm_dirty_bitmap_bytes(memslot);
998 		memset(memslot->dirty_bitmap, 0, n);
999 	}
1000 
1001 	r = 0;
1002 out:
1003 	mutex_unlock(&kvm->slots_lock);
1004 	return r;
1005 
1006 }
1007 
1008 long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
1009 {
1010 	long r;
1011 
1012 	switch (ioctl) {
1013 	default:
1014 		r = -ENOIOCTLCMD;
1015 	}
1016 
1017 	return r;
1018 }
1019 
1020 int kvm_arch_init(void *opaque)
1021 {
1022 	if (kvm_mips_callbacks) {
1023 		kvm_err("kvm: module already exists\n");
1024 		return -EEXIST;
1025 	}
1026 
1027 	return kvm_mips_emulation_init(&kvm_mips_callbacks);
1028 }
1029 
1030 void kvm_arch_exit(void)
1031 {
1032 	kvm_mips_callbacks = NULL;
1033 }
1034 
1035 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
1036 				  struct kvm_sregs *sregs)
1037 {
1038 	return -ENOIOCTLCMD;
1039 }
1040 
1041 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
1042 				  struct kvm_sregs *sregs)
1043 {
1044 	return -ENOIOCTLCMD;
1045 }
1046 
1047 void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
1048 {
1049 }
1050 
1051 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
1052 {
1053 	return -ENOIOCTLCMD;
1054 }
1055 
1056 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
1057 {
1058 	return -ENOIOCTLCMD;
1059 }
1060 
1061 int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
1062 {
1063 	return VM_FAULT_SIGBUS;
1064 }
1065 
1066 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
1067 {
1068 	int r;
1069 
1070 	switch (ext) {
1071 	case KVM_CAP_ONE_REG:
1072 	case KVM_CAP_ENABLE_CAP:
1073 		r = 1;
1074 		break;
1075 	case KVM_CAP_COALESCED_MMIO:
1076 		r = KVM_COALESCED_MMIO_PAGE_OFFSET;
1077 		break;
1078 	case KVM_CAP_MIPS_FPU:
1079 		r = !!cpu_has_fpu;
1080 		break;
1081 	case KVM_CAP_MIPS_MSA:
1082 		/*
1083 		 * We don't support MSA vector partitioning yet:
1084 		 * 1) It would require explicit support which can't be tested
1085 		 *    yet due to lack of support in current hardware.
1086 		 * 2) It extends the state that would need to be saved/restored
1087 		 *    by e.g. QEMU for migration.
1088 		 *
1089 		 * When vector partitioning hardware becomes available, support
1090 		 * could be added by requiring a flag when enabling
1091 		 * KVM_CAP_MIPS_MSA capability to indicate that userland knows
1092 		 * to save/restore the appropriate extra state.
1093 		 */
1094 		r = cpu_has_msa && !(boot_cpu_data.msa_id & MSA_IR_WRPF);
1095 		break;
1096 	default:
1097 		r = 0;
1098 		break;
1099 	}
1100 	return r;
1101 }
1102 
1103 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
1104 {
1105 	return kvm_mips_pending_timer(vcpu);
1106 }
1107 
1108 int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu)
1109 {
1110 	int i;
1111 	struct mips_coproc *cop0;
1112 
1113 	if (!vcpu)
1114 		return -1;
1115 
1116 	kvm_debug("VCPU Register Dump:\n");
1117 	kvm_debug("\tpc = 0x%08lx\n", vcpu->arch.pc);
1118 	kvm_debug("\texceptions: %08lx\n", vcpu->arch.pending_exceptions);
1119 
1120 	for (i = 0; i < 32; i += 4) {
1121 		kvm_debug("\tgpr%02d: %08lx %08lx %08lx %08lx\n", i,
1122 		       vcpu->arch.gprs[i],
1123 		       vcpu->arch.gprs[i + 1],
1124 		       vcpu->arch.gprs[i + 2], vcpu->arch.gprs[i + 3]);
1125 	}
1126 	kvm_debug("\thi: 0x%08lx\n", vcpu->arch.hi);
1127 	kvm_debug("\tlo: 0x%08lx\n", vcpu->arch.lo);
1128 
1129 	cop0 = vcpu->arch.cop0;
1130 	kvm_debug("\tStatus: 0x%08lx, Cause: 0x%08lx\n",
1131 		  kvm_read_c0_guest_status(cop0),
1132 		  kvm_read_c0_guest_cause(cop0));
1133 
1134 	kvm_debug("\tEPC: 0x%08lx\n", kvm_read_c0_guest_epc(cop0));
1135 
1136 	return 0;
1137 }
1138 
1139 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
1140 {
1141 	int i;
1142 
1143 	for (i = 1; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
1144 		vcpu->arch.gprs[i] = regs->gpr[i];
1145 	vcpu->arch.gprs[0] = 0; /* zero is special, and cannot be set. */
1146 	vcpu->arch.hi = regs->hi;
1147 	vcpu->arch.lo = regs->lo;
1148 	vcpu->arch.pc = regs->pc;
1149 
1150 	return 0;
1151 }
1152 
1153 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
1154 {
1155 	int i;
1156 
1157 	for (i = 0; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
1158 		regs->gpr[i] = vcpu->arch.gprs[i];
1159 
1160 	regs->hi = vcpu->arch.hi;
1161 	regs->lo = vcpu->arch.lo;
1162 	regs->pc = vcpu->arch.pc;
1163 
1164 	return 0;
1165 }
1166 
1167 static void kvm_mips_comparecount_func(unsigned long data)
1168 {
1169 	struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
1170 
1171 	kvm_mips_callbacks->queue_timer_int(vcpu);
1172 
1173 	vcpu->arch.wait = 0;
1174 	if (waitqueue_active(&vcpu->wq))
1175 		wake_up_interruptible(&vcpu->wq);
1176 }
1177 
1178 /* low level hrtimer wake routine */
1179 static enum hrtimer_restart kvm_mips_comparecount_wakeup(struct hrtimer *timer)
1180 {
1181 	struct kvm_vcpu *vcpu;
1182 
1183 	vcpu = container_of(timer, struct kvm_vcpu, arch.comparecount_timer);
1184 	kvm_mips_comparecount_func((unsigned long) vcpu);
1185 	return kvm_mips_count_timeout(vcpu);
1186 }
1187 
1188 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
1189 {
1190 	kvm_mips_callbacks->vcpu_init(vcpu);
1191 	hrtimer_init(&vcpu->arch.comparecount_timer, CLOCK_MONOTONIC,
1192 		     HRTIMER_MODE_REL);
1193 	vcpu->arch.comparecount_timer.function = kvm_mips_comparecount_wakeup;
1194 	return 0;
1195 }
1196 
1197 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
1198 				  struct kvm_translation *tr)
1199 {
1200 	return 0;
1201 }
1202 
1203 /* Initial guest state */
1204 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
1205 {
1206 	return kvm_mips_callbacks->vcpu_setup(vcpu);
1207 }
1208 
1209 static void kvm_mips_set_c0_status(void)
1210 {
1211 	uint32_t status = read_c0_status();
1212 
1213 	if (cpu_has_dsp)
1214 		status |= (ST0_MX);
1215 
1216 	write_c0_status(status);
1217 	ehb();
1218 }
1219 
1220 /*
1221  * Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
1222  */
1223 int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
1224 {
1225 	uint32_t cause = vcpu->arch.host_cp0_cause;
1226 	uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
1227 	uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
1228 	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
1229 	enum emulation_result er = EMULATE_DONE;
1230 	int ret = RESUME_GUEST;
1231 
1232 	/* re-enable HTW before enabling interrupts */
1233 	htw_start();
1234 
1235 	/* Set a default exit reason */
1236 	run->exit_reason = KVM_EXIT_UNKNOWN;
1237 	run->ready_for_interrupt_injection = 1;
1238 
1239 	/*
1240 	 * Set the appropriate status bits based on host CPU features,
1241 	 * before we hit the scheduler
1242 	 */
1243 	kvm_mips_set_c0_status();
1244 
1245 	local_irq_enable();
1246 
1247 	kvm_debug("kvm_mips_handle_exit: cause: %#x, PC: %p, kvm_run: %p, kvm_vcpu: %p\n",
1248 			cause, opc, run, vcpu);
1249 
1250 	/*
1251 	 * Do a privilege check, if in UM most of these exit conditions end up
1252 	 * causing an exception to be delivered to the Guest Kernel
1253 	 */
1254 	er = kvm_mips_check_privilege(cause, opc, run, vcpu);
1255 	if (er == EMULATE_PRIV_FAIL) {
1256 		goto skip_emul;
1257 	} else if (er == EMULATE_FAIL) {
1258 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
1259 		ret = RESUME_HOST;
1260 		goto skip_emul;
1261 	}
1262 
1263 	switch (exccode) {
1264 	case T_INT:
1265 		kvm_debug("[%d]T_INT @ %p\n", vcpu->vcpu_id, opc);
1266 
1267 		++vcpu->stat.int_exits;
1268 		trace_kvm_exit(vcpu, INT_EXITS);
1269 
1270 		if (need_resched())
1271 			cond_resched();
1272 
1273 		ret = RESUME_GUEST;
1274 		break;
1275 
1276 	case T_COP_UNUSABLE:
1277 		kvm_debug("T_COP_UNUSABLE: @ PC: %p\n", opc);
1278 
1279 		++vcpu->stat.cop_unusable_exits;
1280 		trace_kvm_exit(vcpu, COP_UNUSABLE_EXITS);
1281 		ret = kvm_mips_callbacks->handle_cop_unusable(vcpu);
1282 		/* XXXKYMA: Might need to return to user space */
1283 		if (run->exit_reason == KVM_EXIT_IRQ_WINDOW_OPEN)
1284 			ret = RESUME_HOST;
1285 		break;
1286 
1287 	case T_TLB_MOD:
1288 		++vcpu->stat.tlbmod_exits;
1289 		trace_kvm_exit(vcpu, TLBMOD_EXITS);
1290 		ret = kvm_mips_callbacks->handle_tlb_mod(vcpu);
1291 		break;
1292 
1293 	case T_TLB_ST_MISS:
1294 		kvm_debug("TLB ST fault:  cause %#x, status %#lx, PC: %p, BadVaddr: %#lx\n",
1295 			  cause, kvm_read_c0_guest_status(vcpu->arch.cop0), opc,
1296 			  badvaddr);
1297 
1298 		++vcpu->stat.tlbmiss_st_exits;
1299 		trace_kvm_exit(vcpu, TLBMISS_ST_EXITS);
1300 		ret = kvm_mips_callbacks->handle_tlb_st_miss(vcpu);
1301 		break;
1302 
1303 	case T_TLB_LD_MISS:
1304 		kvm_debug("TLB LD fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
1305 			  cause, opc, badvaddr);
1306 
1307 		++vcpu->stat.tlbmiss_ld_exits;
1308 		trace_kvm_exit(vcpu, TLBMISS_LD_EXITS);
1309 		ret = kvm_mips_callbacks->handle_tlb_ld_miss(vcpu);
1310 		break;
1311 
1312 	case T_ADDR_ERR_ST:
1313 		++vcpu->stat.addrerr_st_exits;
1314 		trace_kvm_exit(vcpu, ADDRERR_ST_EXITS);
1315 		ret = kvm_mips_callbacks->handle_addr_err_st(vcpu);
1316 		break;
1317 
1318 	case T_ADDR_ERR_LD:
1319 		++vcpu->stat.addrerr_ld_exits;
1320 		trace_kvm_exit(vcpu, ADDRERR_LD_EXITS);
1321 		ret = kvm_mips_callbacks->handle_addr_err_ld(vcpu);
1322 		break;
1323 
1324 	case T_SYSCALL:
1325 		++vcpu->stat.syscall_exits;
1326 		trace_kvm_exit(vcpu, SYSCALL_EXITS);
1327 		ret = kvm_mips_callbacks->handle_syscall(vcpu);
1328 		break;
1329 
1330 	case T_RES_INST:
1331 		++vcpu->stat.resvd_inst_exits;
1332 		trace_kvm_exit(vcpu, RESVD_INST_EXITS);
1333 		ret = kvm_mips_callbacks->handle_res_inst(vcpu);
1334 		break;
1335 
1336 	case T_BREAK:
1337 		++vcpu->stat.break_inst_exits;
1338 		trace_kvm_exit(vcpu, BREAK_INST_EXITS);
1339 		ret = kvm_mips_callbacks->handle_break(vcpu);
1340 		break;
1341 
1342 	case T_TRAP:
1343 		++vcpu->stat.trap_inst_exits;
1344 		trace_kvm_exit(vcpu, TRAP_INST_EXITS);
1345 		ret = kvm_mips_callbacks->handle_trap(vcpu);
1346 		break;
1347 
1348 	case T_MSAFPE:
1349 		++vcpu->stat.msa_fpe_exits;
1350 		trace_kvm_exit(vcpu, MSA_FPE_EXITS);
1351 		ret = kvm_mips_callbacks->handle_msa_fpe(vcpu);
1352 		break;
1353 
1354 	case T_FPE:
1355 		++vcpu->stat.fpe_exits;
1356 		trace_kvm_exit(vcpu, FPE_EXITS);
1357 		ret = kvm_mips_callbacks->handle_fpe(vcpu);
1358 		break;
1359 
1360 	case T_MSADIS:
1361 		++vcpu->stat.msa_disabled_exits;
1362 		trace_kvm_exit(vcpu, MSA_DISABLED_EXITS);
1363 		ret = kvm_mips_callbacks->handle_msa_disabled(vcpu);
1364 		break;
1365 
1366 	default:
1367 		kvm_err("Exception Code: %d, not yet handled, @ PC: %p, inst: 0x%08x  BadVaddr: %#lx Status: %#lx\n",
1368 			exccode, opc, kvm_get_inst(opc, vcpu), badvaddr,
1369 			kvm_read_c0_guest_status(vcpu->arch.cop0));
1370 		kvm_arch_vcpu_dump_regs(vcpu);
1371 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
1372 		ret = RESUME_HOST;
1373 		break;
1374 
1375 	}
1376 
1377 skip_emul:
1378 	local_irq_disable();
1379 
1380 	if (er == EMULATE_DONE && !(ret & RESUME_HOST))
1381 		kvm_mips_deliver_interrupts(vcpu, cause);
1382 
1383 	if (!(ret & RESUME_HOST)) {
1384 		/* Only check for signals if not already exiting to userspace */
1385 		if (signal_pending(current)) {
1386 			run->exit_reason = KVM_EXIT_INTR;
1387 			ret = (-EINTR << 2) | RESUME_HOST;
1388 			++vcpu->stat.signal_exits;
1389 			trace_kvm_exit(vcpu, SIGNAL_EXITS);
1390 		}
1391 	}
1392 
1393 	if (ret == RESUME_GUEST) {
1394 		/*
1395 		 * If FPU / MSA are enabled (i.e. the guest's FPU / MSA context
1396 		 * is live), restore FCR31 / MSACSR.
1397 		 *
1398 		 * This should be before returning to the guest exception
1399 		 * vector, as it may well cause an [MSA] FP exception if there
1400 		 * are pending exception bits unmasked. (see
1401 		 * kvm_mips_csr_die_notifier() for how that is handled).
1402 		 */
1403 		if (kvm_mips_guest_has_fpu(&vcpu->arch) &&
1404 		    read_c0_status() & ST0_CU1)
1405 			__kvm_restore_fcsr(&vcpu->arch);
1406 
1407 		if (kvm_mips_guest_has_msa(&vcpu->arch) &&
1408 		    read_c0_config5() & MIPS_CONF5_MSAEN)
1409 			__kvm_restore_msacsr(&vcpu->arch);
1410 	}
1411 
1412 	/* Disable HTW before returning to guest or host */
1413 	htw_stop();
1414 
1415 	return ret;
1416 }
1417 
1418 /* Enable FPU for guest and restore context */
1419 void kvm_own_fpu(struct kvm_vcpu *vcpu)
1420 {
1421 	struct mips_coproc *cop0 = vcpu->arch.cop0;
1422 	unsigned int sr, cfg5;
1423 
1424 	preempt_disable();
1425 
1426 	sr = kvm_read_c0_guest_status(cop0);
1427 
1428 	/*
1429 	 * If MSA state is already live, it is undefined how it interacts with
1430 	 * FR=0 FPU state, and we don't want to hit reserved instruction
1431 	 * exceptions trying to save the MSA state later when CU=1 && FR=1, so
1432 	 * play it safe and save it first.
1433 	 *
1434 	 * In theory we shouldn't ever hit this case since kvm_lose_fpu() should
1435 	 * get called when guest CU1 is set, however we can't trust the guest
1436 	 * not to clobber the status register directly via the commpage.
1437 	 */
1438 	if (cpu_has_msa && sr & ST0_CU1 && !(sr & ST0_FR) &&
1439 	    vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA)
1440 		kvm_lose_fpu(vcpu);
1441 
1442 	/*
1443 	 * Enable FPU for guest
1444 	 * We set FR and FRE according to guest context
1445 	 */
1446 	change_c0_status(ST0_CU1 | ST0_FR, sr);
1447 	if (cpu_has_fre) {
1448 		cfg5 = kvm_read_c0_guest_config5(cop0);
1449 		change_c0_config5(MIPS_CONF5_FRE, cfg5);
1450 	}
1451 	enable_fpu_hazard();
1452 
1453 	/* If guest FPU state not active, restore it now */
1454 	if (!(vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)) {
1455 		__kvm_restore_fpu(&vcpu->arch);
1456 		vcpu->arch.fpu_inuse |= KVM_MIPS_FPU_FPU;
1457 	}
1458 
1459 	preempt_enable();
1460 }
1461 
1462 #ifdef CONFIG_CPU_HAS_MSA
1463 /* Enable MSA for guest and restore context */
1464 void kvm_own_msa(struct kvm_vcpu *vcpu)
1465 {
1466 	struct mips_coproc *cop0 = vcpu->arch.cop0;
1467 	unsigned int sr, cfg5;
1468 
1469 	preempt_disable();
1470 
1471 	/*
1472 	 * Enable FPU if enabled in guest, since we're restoring FPU context
1473 	 * anyway. We set FR and FRE according to guest context.
1474 	 */
1475 	if (kvm_mips_guest_has_fpu(&vcpu->arch)) {
1476 		sr = kvm_read_c0_guest_status(cop0);
1477 
1478 		/*
1479 		 * If FR=0 FPU state is already live, it is undefined how it
1480 		 * interacts with MSA state, so play it safe and save it first.
1481 		 */
1482 		if (!(sr & ST0_FR) &&
1483 		    (vcpu->arch.fpu_inuse & (KVM_MIPS_FPU_FPU |
1484 				KVM_MIPS_FPU_MSA)) == KVM_MIPS_FPU_FPU)
1485 			kvm_lose_fpu(vcpu);
1486 
1487 		change_c0_status(ST0_CU1 | ST0_FR, sr);
1488 		if (sr & ST0_CU1 && cpu_has_fre) {
1489 			cfg5 = kvm_read_c0_guest_config5(cop0);
1490 			change_c0_config5(MIPS_CONF5_FRE, cfg5);
1491 		}
1492 	}
1493 
1494 	/* Enable MSA for guest */
1495 	set_c0_config5(MIPS_CONF5_MSAEN);
1496 	enable_fpu_hazard();
1497 
1498 	switch (vcpu->arch.fpu_inuse & (KVM_MIPS_FPU_FPU | KVM_MIPS_FPU_MSA)) {
1499 	case KVM_MIPS_FPU_FPU:
1500 		/*
1501 		 * Guest FPU state already loaded, only restore upper MSA state
1502 		 */
1503 		__kvm_restore_msa_upper(&vcpu->arch);
1504 		vcpu->arch.fpu_inuse |= KVM_MIPS_FPU_MSA;
1505 		break;
1506 	case 0:
1507 		/* Neither FPU or MSA already active, restore full MSA state */
1508 		__kvm_restore_msa(&vcpu->arch);
1509 		vcpu->arch.fpu_inuse |= KVM_MIPS_FPU_MSA;
1510 		if (kvm_mips_guest_has_fpu(&vcpu->arch))
1511 			vcpu->arch.fpu_inuse |= KVM_MIPS_FPU_FPU;
1512 		break;
1513 	default:
1514 		break;
1515 	}
1516 
1517 	preempt_enable();
1518 }
1519 #endif
1520 
1521 /* Drop FPU & MSA without saving it */
1522 void kvm_drop_fpu(struct kvm_vcpu *vcpu)
1523 {
1524 	preempt_disable();
1525 	if (cpu_has_msa && vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA) {
1526 		disable_msa();
1527 		vcpu->arch.fpu_inuse &= ~KVM_MIPS_FPU_MSA;
1528 	}
1529 	if (vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU) {
1530 		clear_c0_status(ST0_CU1 | ST0_FR);
1531 		vcpu->arch.fpu_inuse &= ~KVM_MIPS_FPU_FPU;
1532 	}
1533 	preempt_enable();
1534 }
1535 
1536 /* Save and disable FPU & MSA */
1537 void kvm_lose_fpu(struct kvm_vcpu *vcpu)
1538 {
1539 	/*
1540 	 * FPU & MSA get disabled in root context (hardware) when it is disabled
1541 	 * in guest context (software), but the register state in the hardware
1542 	 * may still be in use. This is why we explicitly re-enable the hardware
1543 	 * before saving.
1544 	 */
1545 
1546 	preempt_disable();
1547 	if (cpu_has_msa && vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA) {
1548 		set_c0_config5(MIPS_CONF5_MSAEN);
1549 		enable_fpu_hazard();
1550 
1551 		__kvm_save_msa(&vcpu->arch);
1552 
1553 		/* Disable MSA & FPU */
1554 		disable_msa();
1555 		if (vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)
1556 			clear_c0_status(ST0_CU1 | ST0_FR);
1557 		vcpu->arch.fpu_inuse &= ~(KVM_MIPS_FPU_FPU | KVM_MIPS_FPU_MSA);
1558 	} else if (vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU) {
1559 		set_c0_status(ST0_CU1);
1560 		enable_fpu_hazard();
1561 
1562 		__kvm_save_fpu(&vcpu->arch);
1563 		vcpu->arch.fpu_inuse &= ~KVM_MIPS_FPU_FPU;
1564 
1565 		/* Disable FPU */
1566 		clear_c0_status(ST0_CU1 | ST0_FR);
1567 	}
1568 	preempt_enable();
1569 }
1570 
1571 /*
1572  * Step over a specific ctc1 to FCSR and a specific ctcmsa to MSACSR which are
1573  * used to restore guest FCSR/MSACSR state and may trigger a "harmless" FP/MSAFP
1574  * exception if cause bits are set in the value being written.
1575  */
1576 static int kvm_mips_csr_die_notify(struct notifier_block *self,
1577 				   unsigned long cmd, void *ptr)
1578 {
1579 	struct die_args *args = (struct die_args *)ptr;
1580 	struct pt_regs *regs = args->regs;
1581 	unsigned long pc;
1582 
1583 	/* Only interested in FPE and MSAFPE */
1584 	if (cmd != DIE_FP && cmd != DIE_MSAFP)
1585 		return NOTIFY_DONE;
1586 
1587 	/* Return immediately if guest context isn't active */
1588 	if (!(current->flags & PF_VCPU))
1589 		return NOTIFY_DONE;
1590 
1591 	/* Should never get here from user mode */
1592 	BUG_ON(user_mode(regs));
1593 
1594 	pc = instruction_pointer(regs);
1595 	switch (cmd) {
1596 	case DIE_FP:
1597 		/* match 2nd instruction in __kvm_restore_fcsr */
1598 		if (pc != (unsigned long)&__kvm_restore_fcsr + 4)
1599 			return NOTIFY_DONE;
1600 		break;
1601 	case DIE_MSAFP:
1602 		/* match 2nd/3rd instruction in __kvm_restore_msacsr */
1603 		if (!cpu_has_msa ||
1604 		    pc < (unsigned long)&__kvm_restore_msacsr + 4 ||
1605 		    pc > (unsigned long)&__kvm_restore_msacsr + 8)
1606 			return NOTIFY_DONE;
1607 		break;
1608 	}
1609 
1610 	/* Move PC forward a little and continue executing */
1611 	instruction_pointer(regs) += 4;
1612 
1613 	return NOTIFY_STOP;
1614 }
1615 
1616 static struct notifier_block kvm_mips_csr_die_notifier = {
1617 	.notifier_call = kvm_mips_csr_die_notify,
1618 };
1619 
1620 int __init kvm_mips_init(void)
1621 {
1622 	int ret;
1623 
1624 	ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
1625 
1626 	if (ret)
1627 		return ret;
1628 
1629 	register_die_notifier(&kvm_mips_csr_die_notifier);
1630 
1631 	/*
1632 	 * On MIPS, kernel modules are executed from "mapped space", which
1633 	 * requires TLBs. The TLB handling code is statically linked with
1634 	 * the rest of the kernel (tlb.c) to avoid the possibility of
1635 	 * double faulting. The issue is that the TLB code references
1636 	 * routines that are part of the the KVM module, which are only
1637 	 * available once the module is loaded.
1638 	 */
1639 	kvm_mips_gfn_to_pfn = gfn_to_pfn;
1640 	kvm_mips_release_pfn_clean = kvm_release_pfn_clean;
1641 	kvm_mips_is_error_pfn = is_error_pfn;
1642 
1643 	return 0;
1644 }
1645 
1646 void __exit kvm_mips_exit(void)
1647 {
1648 	kvm_exit();
1649 
1650 	kvm_mips_gfn_to_pfn = NULL;
1651 	kvm_mips_release_pfn_clean = NULL;
1652 	kvm_mips_is_error_pfn = NULL;
1653 
1654 	unregister_die_notifier(&kvm_mips_csr_die_notifier);
1655 }
1656 
1657 module_init(kvm_mips_init);
1658 module_exit(kvm_mips_exit);
1659 
1660 EXPORT_TRACEPOINT_SYMBOL(kvm_exit);
1661