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 TLB handling, this file is part of the Linux host kernel so that
7 * TLB handlers run from KSEG0
8 *
9 * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
10 * Authors: Sanjay Lal <sanjayl@kymasys.com>
11 */
12
13#include <linux/sched.h>
14#include <linux/smp.h>
15#include <linux/mm.h>
16#include <linux/delay.h>
17#include <linux/module.h>
18#include <linux/kvm_host.h>
19#include <linux/srcu.h>
20
21#include <asm/cpu.h>
22#include <asm/bootinfo.h>
23#include <asm/mmu_context.h>
24#include <asm/pgtable.h>
25#include <asm/cacheflush.h>
26#include <asm/tlb.h>
27
28#undef CONFIG_MIPS_MT
29#include <asm/r4kcache.h>
30#define CONFIG_MIPS_MT
31
32#define KVM_GUEST_PC_TLB    0
33#define KVM_GUEST_SP_TLB    1
34
35#define PRIx64 "llx"
36
37atomic_t kvm_mips_instance;
38EXPORT_SYMBOL(kvm_mips_instance);
39
40/* These function pointers are initialized once the KVM module is loaded */
41pfn_t (*kvm_mips_gfn_to_pfn)(struct kvm *kvm, gfn_t gfn);
42EXPORT_SYMBOL(kvm_mips_gfn_to_pfn);
43
44void (*kvm_mips_release_pfn_clean)(pfn_t pfn);
45EXPORT_SYMBOL(kvm_mips_release_pfn_clean);
46
47bool (*kvm_mips_is_error_pfn)(pfn_t pfn);
48EXPORT_SYMBOL(kvm_mips_is_error_pfn);
49
50uint32_t kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
51{
52	return vcpu->arch.guest_kernel_asid[smp_processor_id()] & ASID_MASK;
53}
54
55uint32_t kvm_mips_get_user_asid(struct kvm_vcpu *vcpu)
56{
57	return vcpu->arch.guest_user_asid[smp_processor_id()] & ASID_MASK;
58}
59
60inline uint32_t kvm_mips_get_commpage_asid(struct kvm_vcpu *vcpu)
61{
62	return vcpu->kvm->arch.commpage_tlb;
63}
64
65/* Structure defining an tlb entry data set. */
66
67void kvm_mips_dump_host_tlbs(void)
68{
69	unsigned long old_entryhi;
70	unsigned long old_pagemask;
71	struct kvm_mips_tlb tlb;
72	unsigned long flags;
73	int i;
74
75	local_irq_save(flags);
76
77	old_entryhi = read_c0_entryhi();
78	old_pagemask = read_c0_pagemask();
79
80	kvm_info("HOST TLBs:\n");
81	kvm_info("ASID: %#lx\n", read_c0_entryhi() & ASID_MASK);
82
83	for (i = 0; i < current_cpu_data.tlbsize; i++) {
84		write_c0_index(i);
85		mtc0_tlbw_hazard();
86
87		tlb_read();
88		tlbw_use_hazard();
89
90		tlb.tlb_hi = read_c0_entryhi();
91		tlb.tlb_lo0 = read_c0_entrylo0();
92		tlb.tlb_lo1 = read_c0_entrylo1();
93		tlb.tlb_mask = read_c0_pagemask();
94
95		kvm_info("TLB%c%3d Hi 0x%08lx ",
96			 (tlb.tlb_lo0 | tlb.tlb_lo1) & MIPS3_PG_V ? ' ' : '*',
97			 i, tlb.tlb_hi);
98		kvm_info("Lo0=0x%09" PRIx64 " %c%c attr %lx ",
99			 (uint64_t) mips3_tlbpfn_to_paddr(tlb.tlb_lo0),
100			 (tlb.tlb_lo0 & MIPS3_PG_D) ? 'D' : ' ',
101			 (tlb.tlb_lo0 & MIPS3_PG_G) ? 'G' : ' ',
102			 (tlb.tlb_lo0 >> 3) & 7);
103		kvm_info("Lo1=0x%09" PRIx64 " %c%c attr %lx sz=%lx\n",
104			 (uint64_t) mips3_tlbpfn_to_paddr(tlb.tlb_lo1),
105			 (tlb.tlb_lo1 & MIPS3_PG_D) ? 'D' : ' ',
106			 (tlb.tlb_lo1 & MIPS3_PG_G) ? 'G' : ' ',
107			 (tlb.tlb_lo1 >> 3) & 7, tlb.tlb_mask);
108	}
109	write_c0_entryhi(old_entryhi);
110	write_c0_pagemask(old_pagemask);
111	mtc0_tlbw_hazard();
112	local_irq_restore(flags);
113}
114EXPORT_SYMBOL(kvm_mips_dump_host_tlbs);
115
116void kvm_mips_dump_guest_tlbs(struct kvm_vcpu *vcpu)
117{
118	struct mips_coproc *cop0 = vcpu->arch.cop0;
119	struct kvm_mips_tlb tlb;
120	int i;
121
122	kvm_info("Guest TLBs:\n");
123	kvm_info("Guest EntryHi: %#lx\n", kvm_read_c0_guest_entryhi(cop0));
124
125	for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
126		tlb = vcpu->arch.guest_tlb[i];
127		kvm_info("TLB%c%3d Hi 0x%08lx ",
128			 (tlb.tlb_lo0 | tlb.tlb_lo1) & MIPS3_PG_V ? ' ' : '*',
129			 i, tlb.tlb_hi);
130		kvm_info("Lo0=0x%09" PRIx64 " %c%c attr %lx ",
131			 (uint64_t) mips3_tlbpfn_to_paddr(tlb.tlb_lo0),
132			 (tlb.tlb_lo0 & MIPS3_PG_D) ? 'D' : ' ',
133			 (tlb.tlb_lo0 & MIPS3_PG_G) ? 'G' : ' ',
134			 (tlb.tlb_lo0 >> 3) & 7);
135		kvm_info("Lo1=0x%09" PRIx64 " %c%c attr %lx sz=%lx\n",
136			 (uint64_t) mips3_tlbpfn_to_paddr(tlb.tlb_lo1),
137			 (tlb.tlb_lo1 & MIPS3_PG_D) ? 'D' : ' ',
138			 (tlb.tlb_lo1 & MIPS3_PG_G) ? 'G' : ' ',
139			 (tlb.tlb_lo1 >> 3) & 7, tlb.tlb_mask);
140	}
141}
142EXPORT_SYMBOL(kvm_mips_dump_guest_tlbs);
143
144static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
145{
146	int srcu_idx, err = 0;
147	pfn_t pfn;
148
149	if (kvm->arch.guest_pmap[gfn] != KVM_INVALID_PAGE)
150		return 0;
151
152	srcu_idx = srcu_read_lock(&kvm->srcu);
153	pfn = kvm_mips_gfn_to_pfn(kvm, gfn);
154
155	if (kvm_mips_is_error_pfn(pfn)) {
156		kvm_err("Couldn't get pfn for gfn %#" PRIx64 "!\n", gfn);
157		err = -EFAULT;
158		goto out;
159	}
160
161	kvm->arch.guest_pmap[gfn] = pfn;
162out:
163	srcu_read_unlock(&kvm->srcu, srcu_idx);
164	return err;
165}
166
167/* Translate guest KSEG0 addresses to Host PA */
168unsigned long kvm_mips_translate_guest_kseg0_to_hpa(struct kvm_vcpu *vcpu,
169						    unsigned long gva)
170{
171	gfn_t gfn;
172	uint32_t offset = gva & ~PAGE_MASK;
173	struct kvm *kvm = vcpu->kvm;
174
175	if (KVM_GUEST_KSEGX(gva) != KVM_GUEST_KSEG0) {
176		kvm_err("%s/%p: Invalid gva: %#lx\n", __func__,
177			__builtin_return_address(0), gva);
178		return KVM_INVALID_PAGE;
179	}
180
181	gfn = (KVM_GUEST_CPHYSADDR(gva) >> PAGE_SHIFT);
182
183	if (gfn >= kvm->arch.guest_pmap_npages) {
184		kvm_err("%s: Invalid gfn: %#llx, GVA: %#lx\n", __func__, gfn,
185			gva);
186		return KVM_INVALID_PAGE;
187	}
188
189	if (kvm_mips_map_page(vcpu->kvm, gfn) < 0)
190		return KVM_INVALID_ADDR;
191
192	return (kvm->arch.guest_pmap[gfn] << PAGE_SHIFT) + offset;
193}
194EXPORT_SYMBOL(kvm_mips_translate_guest_kseg0_to_hpa);
195
196/* XXXKYMA: Must be called with interrupts disabled */
197/* set flush_dcache_mask == 0 if no dcache flush required */
198int kvm_mips_host_tlb_write(struct kvm_vcpu *vcpu, unsigned long entryhi,
199			    unsigned long entrylo0, unsigned long entrylo1,
200			    int flush_dcache_mask)
201{
202	unsigned long flags;
203	unsigned long old_entryhi;
204	int idx;
205
206	local_irq_save(flags);
207
208	old_entryhi = read_c0_entryhi();
209	write_c0_entryhi(entryhi);
210	mtc0_tlbw_hazard();
211
212	tlb_probe();
213	tlb_probe_hazard();
214	idx = read_c0_index();
215
216	if (idx > current_cpu_data.tlbsize) {
217		kvm_err("%s: Invalid Index: %d\n", __func__, idx);
218		kvm_mips_dump_host_tlbs();
219		local_irq_restore(flags);
220		return -1;
221	}
222
223	write_c0_entrylo0(entrylo0);
224	write_c0_entrylo1(entrylo1);
225	mtc0_tlbw_hazard();
226
227	if (idx < 0)
228		tlb_write_random();
229	else
230		tlb_write_indexed();
231	tlbw_use_hazard();
232
233	kvm_debug("@ %#lx idx: %2d [entryhi(R): %#lx] entrylo0(R): 0x%08lx, entrylo1(R): 0x%08lx\n",
234		  vcpu->arch.pc, idx, read_c0_entryhi(),
235		  read_c0_entrylo0(), read_c0_entrylo1());
236
237	/* Flush D-cache */
238	if (flush_dcache_mask) {
239		if (entrylo0 & MIPS3_PG_V) {
240			++vcpu->stat.flush_dcache_exits;
241			flush_data_cache_page((entryhi & VPN2_MASK) &
242					      ~flush_dcache_mask);
243		}
244		if (entrylo1 & MIPS3_PG_V) {
245			++vcpu->stat.flush_dcache_exits;
246			flush_data_cache_page(((entryhi & VPN2_MASK) &
247					       ~flush_dcache_mask) |
248					      (0x1 << PAGE_SHIFT));
249		}
250	}
251
252	/* Restore old ASID */
253	write_c0_entryhi(old_entryhi);
254	mtc0_tlbw_hazard();
255	tlbw_use_hazard();
256	local_irq_restore(flags);
257	return 0;
258}
259
260/* XXXKYMA: Must be called with interrupts disabled */
261int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr,
262				    struct kvm_vcpu *vcpu)
263{
264	gfn_t gfn;
265	pfn_t pfn0, pfn1;
266	unsigned long vaddr = 0;
267	unsigned long entryhi = 0, entrylo0 = 0, entrylo1 = 0;
268	int even;
269	struct kvm *kvm = vcpu->kvm;
270	const int flush_dcache_mask = 0;
271
272	if (KVM_GUEST_KSEGX(badvaddr) != KVM_GUEST_KSEG0) {
273		kvm_err("%s: Invalid BadVaddr: %#lx\n", __func__, badvaddr);
274		kvm_mips_dump_host_tlbs();
275		return -1;
276	}
277
278	gfn = (KVM_GUEST_CPHYSADDR(badvaddr) >> PAGE_SHIFT);
279	if (gfn >= kvm->arch.guest_pmap_npages) {
280		kvm_err("%s: Invalid gfn: %#llx, BadVaddr: %#lx\n", __func__,
281			gfn, badvaddr);
282		kvm_mips_dump_host_tlbs();
283		return -1;
284	}
285	even = !(gfn & 0x1);
286	vaddr = badvaddr & (PAGE_MASK << 1);
287
288	if (kvm_mips_map_page(vcpu->kvm, gfn) < 0)
289		return -1;
290
291	if (kvm_mips_map_page(vcpu->kvm, gfn ^ 0x1) < 0)
292		return -1;
293
294	if (even) {
295		pfn0 = kvm->arch.guest_pmap[gfn];
296		pfn1 = kvm->arch.guest_pmap[gfn ^ 0x1];
297	} else {
298		pfn0 = kvm->arch.guest_pmap[gfn ^ 0x1];
299		pfn1 = kvm->arch.guest_pmap[gfn];
300	}
301
302	entryhi = (vaddr | kvm_mips_get_kernel_asid(vcpu));
303	entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) | (0x3 << 3) |
304		   (1 << 2) | (0x1 << 1);
305	entrylo1 = mips3_paddr_to_tlbpfn(pfn1 << PAGE_SHIFT) | (0x3 << 3) |
306		   (1 << 2) | (0x1 << 1);
307
308	return kvm_mips_host_tlb_write(vcpu, entryhi, entrylo0, entrylo1,
309				       flush_dcache_mask);
310}
311EXPORT_SYMBOL(kvm_mips_handle_kseg0_tlb_fault);
312
313int kvm_mips_handle_commpage_tlb_fault(unsigned long badvaddr,
314	struct kvm_vcpu *vcpu)
315{
316	pfn_t pfn0, pfn1;
317	unsigned long flags, old_entryhi = 0, vaddr = 0;
318	unsigned long entrylo0 = 0, entrylo1 = 0;
319
320	pfn0 = CPHYSADDR(vcpu->arch.kseg0_commpage) >> PAGE_SHIFT;
321	pfn1 = 0;
322	entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) | (0x3 << 3) |
323		   (1 << 2) | (0x1 << 1);
324	entrylo1 = 0;
325
326	local_irq_save(flags);
327
328	old_entryhi = read_c0_entryhi();
329	vaddr = badvaddr & (PAGE_MASK << 1);
330	write_c0_entryhi(vaddr | kvm_mips_get_kernel_asid(vcpu));
331	mtc0_tlbw_hazard();
332	write_c0_entrylo0(entrylo0);
333	mtc0_tlbw_hazard();
334	write_c0_entrylo1(entrylo1);
335	mtc0_tlbw_hazard();
336	write_c0_index(kvm_mips_get_commpage_asid(vcpu));
337	mtc0_tlbw_hazard();
338	tlb_write_indexed();
339	mtc0_tlbw_hazard();
340	tlbw_use_hazard();
341
342	kvm_debug("@ %#lx idx: %2d [entryhi(R): %#lx] entrylo0 (R): 0x%08lx, entrylo1(R): 0x%08lx\n",
343		  vcpu->arch.pc, read_c0_index(), read_c0_entryhi(),
344		  read_c0_entrylo0(), read_c0_entrylo1());
345
346	/* Restore old ASID */
347	write_c0_entryhi(old_entryhi);
348	mtc0_tlbw_hazard();
349	tlbw_use_hazard();
350	local_irq_restore(flags);
351
352	return 0;
353}
354EXPORT_SYMBOL(kvm_mips_handle_commpage_tlb_fault);
355
356int kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu *vcpu,
357					 struct kvm_mips_tlb *tlb,
358					 unsigned long *hpa0,
359					 unsigned long *hpa1)
360{
361	unsigned long entryhi = 0, entrylo0 = 0, entrylo1 = 0;
362	struct kvm *kvm = vcpu->kvm;
363	pfn_t pfn0, pfn1;
364
365	if ((tlb->tlb_hi & VPN2_MASK) == 0) {
366		pfn0 = 0;
367		pfn1 = 0;
368	} else {
369		if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo0)
370					   >> PAGE_SHIFT) < 0)
371			return -1;
372
373		if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo1)
374					   >> PAGE_SHIFT) < 0)
375			return -1;
376
377		pfn0 = kvm->arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb->tlb_lo0)
378					    >> PAGE_SHIFT];
379		pfn1 = kvm->arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb->tlb_lo1)
380					    >> PAGE_SHIFT];
381	}
382
383	if (hpa0)
384		*hpa0 = pfn0 << PAGE_SHIFT;
385
386	if (hpa1)
387		*hpa1 = pfn1 << PAGE_SHIFT;
388
389	/* Get attributes from the Guest TLB */
390	entryhi = (tlb->tlb_hi & VPN2_MASK) | (KVM_GUEST_KERNEL_MODE(vcpu) ?
391					       kvm_mips_get_kernel_asid(vcpu) :
392					       kvm_mips_get_user_asid(vcpu));
393	entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) | (0x3 << 3) |
394		   (tlb->tlb_lo0 & MIPS3_PG_D) | (tlb->tlb_lo0 & MIPS3_PG_V);
395	entrylo1 = mips3_paddr_to_tlbpfn(pfn1 << PAGE_SHIFT) | (0x3 << 3) |
396		   (tlb->tlb_lo1 & MIPS3_PG_D) | (tlb->tlb_lo1 & MIPS3_PG_V);
397
398	kvm_debug("@ %#lx tlb_lo0: 0x%08lx tlb_lo1: 0x%08lx\n", vcpu->arch.pc,
399		  tlb->tlb_lo0, tlb->tlb_lo1);
400
401	return kvm_mips_host_tlb_write(vcpu, entryhi, entrylo0, entrylo1,
402				       tlb->tlb_mask);
403}
404EXPORT_SYMBOL(kvm_mips_handle_mapped_seg_tlb_fault);
405
406int kvm_mips_guest_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long entryhi)
407{
408	int i;
409	int index = -1;
410	struct kvm_mips_tlb *tlb = vcpu->arch.guest_tlb;
411
412	for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
413		if (TLB_HI_VPN2_HIT(tlb[i], entryhi) &&
414		    TLB_HI_ASID_HIT(tlb[i], entryhi)) {
415			index = i;
416			break;
417		}
418	}
419
420	kvm_debug("%s: entryhi: %#lx, index: %d lo0: %#lx, lo1: %#lx\n",
421		  __func__, entryhi, index, tlb[i].tlb_lo0, tlb[i].tlb_lo1);
422
423	return index;
424}
425EXPORT_SYMBOL(kvm_mips_guest_tlb_lookup);
426
427int kvm_mips_host_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long vaddr)
428{
429	unsigned long old_entryhi, flags;
430	int idx;
431
432	local_irq_save(flags);
433
434	old_entryhi = read_c0_entryhi();
435
436	if (KVM_GUEST_KERNEL_MODE(vcpu))
437		write_c0_entryhi((vaddr & VPN2_MASK) |
438				 kvm_mips_get_kernel_asid(vcpu));
439	else {
440		write_c0_entryhi((vaddr & VPN2_MASK) |
441				 kvm_mips_get_user_asid(vcpu));
442	}
443
444	mtc0_tlbw_hazard();
445
446	tlb_probe();
447	tlb_probe_hazard();
448	idx = read_c0_index();
449
450	/* Restore old ASID */
451	write_c0_entryhi(old_entryhi);
452	mtc0_tlbw_hazard();
453	tlbw_use_hazard();
454
455	local_irq_restore(flags);
456
457	kvm_debug("Host TLB lookup, %#lx, idx: %2d\n", vaddr, idx);
458
459	return idx;
460}
461EXPORT_SYMBOL(kvm_mips_host_tlb_lookup);
462
463int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va)
464{
465	int idx;
466	unsigned long flags, old_entryhi;
467
468	local_irq_save(flags);
469
470	old_entryhi = read_c0_entryhi();
471
472	write_c0_entryhi((va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu));
473	mtc0_tlbw_hazard();
474
475	tlb_probe();
476	tlb_probe_hazard();
477	idx = read_c0_index();
478
479	if (idx >= current_cpu_data.tlbsize)
480		BUG();
481
482	if (idx > 0) {
483		write_c0_entryhi(UNIQUE_ENTRYHI(idx));
484		mtc0_tlbw_hazard();
485
486		write_c0_entrylo0(0);
487		mtc0_tlbw_hazard();
488
489		write_c0_entrylo1(0);
490		mtc0_tlbw_hazard();
491
492		tlb_write_indexed();
493		mtc0_tlbw_hazard();
494	}
495
496	write_c0_entryhi(old_entryhi);
497	mtc0_tlbw_hazard();
498	tlbw_use_hazard();
499
500	local_irq_restore(flags);
501
502	if (idx > 0)
503		kvm_debug("%s: Invalidated entryhi %#lx @ idx %d\n", __func__,
504			  (va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu), idx);
505
506	return 0;
507}
508EXPORT_SYMBOL(kvm_mips_host_tlb_inv);
509
510/* XXXKYMA: Fix Guest USER/KERNEL no longer share the same ASID */
511int kvm_mips_host_tlb_inv_index(struct kvm_vcpu *vcpu, int index)
512{
513	unsigned long flags, old_entryhi;
514
515	if (index >= current_cpu_data.tlbsize)
516		BUG();
517
518	local_irq_save(flags);
519
520	old_entryhi = read_c0_entryhi();
521
522	write_c0_entryhi(UNIQUE_ENTRYHI(index));
523	mtc0_tlbw_hazard();
524
525	write_c0_index(index);
526	mtc0_tlbw_hazard();
527
528	write_c0_entrylo0(0);
529	mtc0_tlbw_hazard();
530
531	write_c0_entrylo1(0);
532	mtc0_tlbw_hazard();
533
534	tlb_write_indexed();
535	mtc0_tlbw_hazard();
536	tlbw_use_hazard();
537
538	write_c0_entryhi(old_entryhi);
539	mtc0_tlbw_hazard();
540	tlbw_use_hazard();
541
542	local_irq_restore(flags);
543
544	return 0;
545}
546
547void kvm_mips_flush_host_tlb(int skip_kseg0)
548{
549	unsigned long flags;
550	unsigned long old_entryhi, entryhi;
551	unsigned long old_pagemask;
552	int entry = 0;
553	int maxentry = current_cpu_data.tlbsize;
554
555	local_irq_save(flags);
556
557	old_entryhi = read_c0_entryhi();
558	old_pagemask = read_c0_pagemask();
559
560	/* Blast 'em all away. */
561	for (entry = 0; entry < maxentry; entry++) {
562		write_c0_index(entry);
563		mtc0_tlbw_hazard();
564
565		if (skip_kseg0) {
566			tlb_read();
567			tlbw_use_hazard();
568
569			entryhi = read_c0_entryhi();
570
571			/* Don't blow away guest kernel entries */
572			if (KVM_GUEST_KSEGX(entryhi) == KVM_GUEST_KSEG0)
573				continue;
574		}
575
576		/* Make sure all entries differ. */
577		write_c0_entryhi(UNIQUE_ENTRYHI(entry));
578		mtc0_tlbw_hazard();
579		write_c0_entrylo0(0);
580		mtc0_tlbw_hazard();
581		write_c0_entrylo1(0);
582		mtc0_tlbw_hazard();
583
584		tlb_write_indexed();
585		mtc0_tlbw_hazard();
586	}
587
588	tlbw_use_hazard();
589
590	write_c0_entryhi(old_entryhi);
591	write_c0_pagemask(old_pagemask);
592	mtc0_tlbw_hazard();
593	tlbw_use_hazard();
594
595	local_irq_restore(flags);
596}
597EXPORT_SYMBOL(kvm_mips_flush_host_tlb);
598
599void kvm_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu,
600			     struct kvm_vcpu *vcpu)
601{
602	unsigned long asid = asid_cache(cpu);
603
604	asid += ASID_INC;
605	if (!(asid & ASID_MASK)) {
606		if (cpu_has_vtag_icache)
607			flush_icache_all();
608
609		kvm_local_flush_tlb_all();      /* start new asid cycle */
610
611		if (!asid)      /* fix version if needed */
612			asid = ASID_FIRST_VERSION;
613	}
614
615	cpu_context(cpu, mm) = asid_cache(cpu) = asid;
616}
617
618void kvm_local_flush_tlb_all(void)
619{
620	unsigned long flags;
621	unsigned long old_ctx;
622	int entry = 0;
623
624	local_irq_save(flags);
625	/* Save old context and create impossible VPN2 value */
626	old_ctx = read_c0_entryhi();
627	write_c0_entrylo0(0);
628	write_c0_entrylo1(0);
629
630	/* Blast 'em all away. */
631	while (entry < current_cpu_data.tlbsize) {
632		/* Make sure all entries differ. */
633		write_c0_entryhi(UNIQUE_ENTRYHI(entry));
634		write_c0_index(entry);
635		mtc0_tlbw_hazard();
636		tlb_write_indexed();
637		entry++;
638	}
639	tlbw_use_hazard();
640	write_c0_entryhi(old_ctx);
641	mtc0_tlbw_hazard();
642
643	local_irq_restore(flags);
644}
645EXPORT_SYMBOL(kvm_local_flush_tlb_all);
646
647/**
648 * kvm_mips_migrate_count() - Migrate timer.
649 * @vcpu:	Virtual CPU.
650 *
651 * Migrate CP0_Count hrtimer to the current CPU by cancelling and restarting it
652 * if it was running prior to being cancelled.
653 *
654 * Must be called when the VCPU is migrated to a different CPU to ensure that
655 * timer expiry during guest execution interrupts the guest and causes the
656 * interrupt to be delivered in a timely manner.
657 */
658static void kvm_mips_migrate_count(struct kvm_vcpu *vcpu)
659{
660	if (hrtimer_cancel(&vcpu->arch.comparecount_timer))
661		hrtimer_restart(&vcpu->arch.comparecount_timer);
662}
663
664/* Restore ASID once we are scheduled back after preemption */
665void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
666{
667	unsigned long flags;
668	int newasid = 0;
669
670	kvm_debug("%s: vcpu %p, cpu: %d\n", __func__, vcpu, cpu);
671
672	/* Alocate new kernel and user ASIDs if needed */
673
674	local_irq_save(flags);
675
676	if (((vcpu->arch.
677	      guest_kernel_asid[cpu] ^ asid_cache(cpu)) & ASID_VERSION_MASK)) {
678		kvm_get_new_mmu_context(&vcpu->arch.guest_kernel_mm, cpu, vcpu);
679		vcpu->arch.guest_kernel_asid[cpu] =
680		    vcpu->arch.guest_kernel_mm.context.asid[cpu];
681		kvm_get_new_mmu_context(&vcpu->arch.guest_user_mm, cpu, vcpu);
682		vcpu->arch.guest_user_asid[cpu] =
683		    vcpu->arch.guest_user_mm.context.asid[cpu];
684		newasid++;
685
686		kvm_debug("[%d]: cpu_context: %#lx\n", cpu,
687			  cpu_context(cpu, current->mm));
688		kvm_debug("[%d]: Allocated new ASID for Guest Kernel: %#x\n",
689			  cpu, vcpu->arch.guest_kernel_asid[cpu]);
690		kvm_debug("[%d]: Allocated new ASID for Guest User: %#x\n", cpu,
691			  vcpu->arch.guest_user_asid[cpu]);
692	}
693
694	if (vcpu->arch.last_sched_cpu != cpu) {
695		kvm_debug("[%d->%d]KVM VCPU[%d] switch\n",
696			  vcpu->arch.last_sched_cpu, cpu, vcpu->vcpu_id);
697		/*
698		 * Migrate the timer interrupt to the current CPU so that it
699		 * always interrupts the guest and synchronously triggers a
700		 * guest timer interrupt.
701		 */
702		kvm_mips_migrate_count(vcpu);
703	}
704
705	if (!newasid) {
706		/*
707		 * If we preempted while the guest was executing, then reload
708		 * the pre-empted ASID
709		 */
710		if (current->flags & PF_VCPU) {
711			write_c0_entryhi(vcpu->arch.
712					 preempt_entryhi & ASID_MASK);
713			ehb();
714		}
715	} else {
716		/* New ASIDs were allocated for the VM */
717
718		/*
719		 * Were we in guest context? If so then the pre-empted ASID is
720		 * no longer valid, we need to set it to what it should be based
721		 * on the mode of the Guest (Kernel/User)
722		 */
723		if (current->flags & PF_VCPU) {
724			if (KVM_GUEST_KERNEL_MODE(vcpu))
725				write_c0_entryhi(vcpu->arch.
726						 guest_kernel_asid[cpu] &
727						 ASID_MASK);
728			else
729				write_c0_entryhi(vcpu->arch.
730						 guest_user_asid[cpu] &
731						 ASID_MASK);
732			ehb();
733		}
734	}
735
736	/* restore guest state to registers */
737	kvm_mips_callbacks->vcpu_set_regs(vcpu);
738
739	local_irq_restore(flags);
740
741}
742EXPORT_SYMBOL(kvm_arch_vcpu_load);
743
744/* ASID can change if another task is scheduled during preemption */
745void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
746{
747	unsigned long flags;
748	uint32_t cpu;
749
750	local_irq_save(flags);
751
752	cpu = smp_processor_id();
753
754	vcpu->arch.preempt_entryhi = read_c0_entryhi();
755	vcpu->arch.last_sched_cpu = cpu;
756
757	/* save guest state in registers */
758	kvm_mips_callbacks->vcpu_get_regs(vcpu);
759
760	if (((cpu_context(cpu, current->mm) ^ asid_cache(cpu)) &
761	     ASID_VERSION_MASK)) {
762		kvm_debug("%s: Dropping MMU Context:  %#lx\n", __func__,
763			  cpu_context(cpu, current->mm));
764		drop_mmu_context(current->mm, cpu);
765	}
766	write_c0_entryhi(cpu_asid(cpu, current->mm));
767	ehb();
768
769	local_irq_restore(flags);
770}
771EXPORT_SYMBOL(kvm_arch_vcpu_put);
772
773uint32_t kvm_get_inst(uint32_t *opc, struct kvm_vcpu *vcpu)
774{
775	struct mips_coproc *cop0 = vcpu->arch.cop0;
776	unsigned long paddr, flags, vpn2, asid;
777	uint32_t inst;
778	int index;
779
780	if (KVM_GUEST_KSEGX((unsigned long) opc) < KVM_GUEST_KSEG0 ||
781	    KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
782		local_irq_save(flags);
783		index = kvm_mips_host_tlb_lookup(vcpu, (unsigned long) opc);
784		if (index >= 0) {
785			inst = *(opc);
786		} else {
787			vpn2 = (unsigned long) opc & VPN2_MASK;
788			asid = kvm_read_c0_guest_entryhi(cop0) & ASID_MASK;
789			index = kvm_mips_guest_tlb_lookup(vcpu, vpn2 | asid);
790			if (index < 0) {
791				kvm_err("%s: get_user_failed for %p, vcpu: %p, ASID: %#lx\n",
792					__func__, opc, vcpu, read_c0_entryhi());
793				kvm_mips_dump_host_tlbs();
794				local_irq_restore(flags);
795				return KVM_INVALID_INST;
796			}
797			kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
798							     &vcpu->arch.
799							     guest_tlb[index],
800							     NULL, NULL);
801			inst = *(opc);
802		}
803		local_irq_restore(flags);
804	} else if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
805		paddr =
806		    kvm_mips_translate_guest_kseg0_to_hpa(vcpu,
807							  (unsigned long) opc);
808		inst = *(uint32_t *) CKSEG0ADDR(paddr);
809	} else {
810		kvm_err("%s: illegal address: %p\n", __func__, opc);
811		return KVM_INVALID_INST;
812	}
813
814	return inst;
815}
816EXPORT_SYMBOL(kvm_get_inst);
817