1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License, version 2, as
4 * published by the Free Software Foundation.
5 *
6 * Copyright 2010-2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
7 */
8
9 #include <linux/types.h>
10 #include <linux/string.h>
11 #include <linux/kvm.h>
12 #include <linux/kvm_host.h>
13 #include <linux/hugetlb.h>
14 #include <linux/module.h>
15
16 #include <asm/tlbflush.h>
17 #include <asm/kvm_ppc.h>
18 #include <asm/kvm_book3s.h>
19 #include <asm/mmu-hash64.h>
20 #include <asm/hvcall.h>
21 #include <asm/synch.h>
22 #include <asm/ppc-opcode.h>
23
24 /* Translate address of a vmalloc'd thing to a linear map address */
real_vmalloc_addr(void * x)25 static void *real_vmalloc_addr(void *x)
26 {
27 unsigned long addr = (unsigned long) x;
28 pte_t *p;
29
30 p = find_linux_pte(swapper_pg_dir, addr);
31 if (!p || !pte_present(*p))
32 return NULL;
33 /* assume we don't have huge pages in vmalloc space... */
34 addr = (pte_pfn(*p) << PAGE_SHIFT) | (addr & ~PAGE_MASK);
35 return __va(addr);
36 }
37
38 /*
39 * Add this HPTE into the chain for the real page.
40 * Must be called with the chain locked; it unlocks the chain.
41 */
kvmppc_add_revmap_chain(struct kvm * kvm,struct revmap_entry * rev,unsigned long * rmap,long pte_index,int realmode)42 void kvmppc_add_revmap_chain(struct kvm *kvm, struct revmap_entry *rev,
43 unsigned long *rmap, long pte_index, int realmode)
44 {
45 struct revmap_entry *head, *tail;
46 unsigned long i;
47
48 if (*rmap & KVMPPC_RMAP_PRESENT) {
49 i = *rmap & KVMPPC_RMAP_INDEX;
50 head = &kvm->arch.revmap[i];
51 if (realmode)
52 head = real_vmalloc_addr(head);
53 tail = &kvm->arch.revmap[head->back];
54 if (realmode)
55 tail = real_vmalloc_addr(tail);
56 rev->forw = i;
57 rev->back = head->back;
58 tail->forw = pte_index;
59 head->back = pte_index;
60 } else {
61 rev->forw = rev->back = pte_index;
62 i = pte_index;
63 }
64 smp_wmb();
65 *rmap = i | KVMPPC_RMAP_REFERENCED | KVMPPC_RMAP_PRESENT; /* unlock */
66 }
67 EXPORT_SYMBOL_GPL(kvmppc_add_revmap_chain);
68
69 /* Remove this HPTE from the chain for a real page */
remove_revmap_chain(struct kvm * kvm,long pte_index,struct revmap_entry * rev,unsigned long hpte_v,unsigned long hpte_r)70 static void remove_revmap_chain(struct kvm *kvm, long pte_index,
71 struct revmap_entry *rev,
72 unsigned long hpte_v, unsigned long hpte_r)
73 {
74 struct revmap_entry *next, *prev;
75 unsigned long gfn, ptel, head;
76 struct kvm_memory_slot *memslot;
77 unsigned long *rmap;
78 unsigned long rcbits;
79
80 rcbits = hpte_r & (HPTE_R_R | HPTE_R_C);
81 ptel = rev->guest_rpte |= rcbits;
82 gfn = hpte_rpn(ptel, hpte_page_size(hpte_v, ptel));
83 memslot = __gfn_to_memslot(kvm_memslots(kvm), gfn);
84 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
85 return;
86
87 rmap = real_vmalloc_addr(&memslot->rmap[gfn - memslot->base_gfn]);
88 lock_rmap(rmap);
89
90 head = *rmap & KVMPPC_RMAP_INDEX;
91 next = real_vmalloc_addr(&kvm->arch.revmap[rev->forw]);
92 prev = real_vmalloc_addr(&kvm->arch.revmap[rev->back]);
93 next->back = rev->back;
94 prev->forw = rev->forw;
95 if (head == pte_index) {
96 head = rev->forw;
97 if (head == pte_index)
98 *rmap &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
99 else
100 *rmap = (*rmap & ~KVMPPC_RMAP_INDEX) | head;
101 }
102 *rmap |= rcbits << KVMPPC_RMAP_RC_SHIFT;
103 unlock_rmap(rmap);
104 }
105
lookup_linux_pte(struct kvm_vcpu * vcpu,unsigned long hva,int writing,unsigned long * pte_sizep)106 static pte_t lookup_linux_pte(struct kvm_vcpu *vcpu, unsigned long hva,
107 int writing, unsigned long *pte_sizep)
108 {
109 pte_t *ptep;
110 unsigned long ps = *pte_sizep;
111 unsigned int shift;
112
113 ptep = find_linux_pte_or_hugepte(vcpu->arch.pgdir, hva, &shift);
114 if (!ptep)
115 return __pte(0);
116 if (shift)
117 *pte_sizep = 1ul << shift;
118 else
119 *pte_sizep = PAGE_SIZE;
120 if (ps > *pte_sizep)
121 return __pte(0);
122 if (!pte_present(*ptep))
123 return __pte(0);
124 return kvmppc_read_update_linux_pte(ptep, writing);
125 }
126
unlock_hpte(unsigned long * hpte,unsigned long hpte_v)127 static inline void unlock_hpte(unsigned long *hpte, unsigned long hpte_v)
128 {
129 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory");
130 hpte[0] = hpte_v;
131 }
132
kvmppc_h_enter(struct kvm_vcpu * vcpu,unsigned long flags,long pte_index,unsigned long pteh,unsigned long ptel)133 long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
134 long pte_index, unsigned long pteh, unsigned long ptel)
135 {
136 struct kvm *kvm = vcpu->kvm;
137 unsigned long i, pa, gpa, gfn, psize;
138 unsigned long slot_fn, hva;
139 unsigned long *hpte;
140 struct revmap_entry *rev;
141 unsigned long g_ptel = ptel;
142 struct kvm_memory_slot *memslot;
143 unsigned long *physp, pte_size;
144 unsigned long is_io;
145 unsigned long *rmap;
146 pte_t pte;
147 unsigned int writing;
148 unsigned long mmu_seq;
149 unsigned long rcbits;
150 bool realmode = vcpu->arch.vcore->vcore_state == VCORE_RUNNING;
151
152 psize = hpte_page_size(pteh, ptel);
153 if (!psize)
154 return H_PARAMETER;
155 writing = hpte_is_writable(ptel);
156 pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID);
157
158 /* used later to detect if we might have been invalidated */
159 mmu_seq = kvm->mmu_notifier_seq;
160 smp_rmb();
161
162 /* Find the memslot (if any) for this address */
163 gpa = (ptel & HPTE_R_RPN) & ~(psize - 1);
164 gfn = gpa >> PAGE_SHIFT;
165 memslot = __gfn_to_memslot(kvm_memslots(kvm), gfn);
166 pa = 0;
167 is_io = ~0ul;
168 rmap = NULL;
169 if (!(memslot && !(memslot->flags & KVM_MEMSLOT_INVALID))) {
170 /* PPC970 can't do emulated MMIO */
171 if (!cpu_has_feature(CPU_FTR_ARCH_206))
172 return H_PARAMETER;
173 /* Emulated MMIO - mark this with key=31 */
174 pteh |= HPTE_V_ABSENT;
175 ptel |= HPTE_R_KEY_HI | HPTE_R_KEY_LO;
176 goto do_insert;
177 }
178
179 /* Check if the requested page fits entirely in the memslot. */
180 if (!slot_is_aligned(memslot, psize))
181 return H_PARAMETER;
182 slot_fn = gfn - memslot->base_gfn;
183 rmap = &memslot->rmap[slot_fn];
184
185 if (!kvm->arch.using_mmu_notifiers) {
186 physp = kvm->arch.slot_phys[memslot->id];
187 if (!physp)
188 return H_PARAMETER;
189 physp += slot_fn;
190 if (realmode)
191 physp = real_vmalloc_addr(physp);
192 pa = *physp;
193 if (!pa)
194 return H_TOO_HARD;
195 is_io = pa & (HPTE_R_I | HPTE_R_W);
196 pte_size = PAGE_SIZE << (pa & KVMPPC_PAGE_ORDER_MASK);
197 pa &= PAGE_MASK;
198 } else {
199 /* Translate to host virtual address */
200 hva = gfn_to_hva_memslot(memslot, gfn);
201
202 /* Look up the Linux PTE for the backing page */
203 pte_size = psize;
204 pte = lookup_linux_pte(vcpu, hva, writing, &pte_size);
205 if (pte_present(pte)) {
206 if (writing && !pte_write(pte))
207 /* make the actual HPTE be read-only */
208 ptel = hpte_make_readonly(ptel);
209 is_io = hpte_cache_bits(pte_val(pte));
210 pa = pte_pfn(pte) << PAGE_SHIFT;
211 }
212 }
213 if (pte_size < psize)
214 return H_PARAMETER;
215 if (pa && pte_size > psize)
216 pa |= gpa & (pte_size - 1);
217
218 ptel &= ~(HPTE_R_PP0 - psize);
219 ptel |= pa;
220
221 if (pa)
222 pteh |= HPTE_V_VALID;
223 else
224 pteh |= HPTE_V_ABSENT;
225
226 /* Check WIMG */
227 if (is_io != ~0ul && !hpte_cache_flags_ok(ptel, is_io)) {
228 if (is_io)
229 return H_PARAMETER;
230 /*
231 * Allow guest to map emulated device memory as
232 * uncacheable, but actually make it cacheable.
233 */
234 ptel &= ~(HPTE_R_W|HPTE_R_I|HPTE_R_G);
235 ptel |= HPTE_R_M;
236 }
237
238 /* Find and lock the HPTEG slot to use */
239 do_insert:
240 if (pte_index >= HPT_NPTE)
241 return H_PARAMETER;
242 if (likely((flags & H_EXACT) == 0)) {
243 pte_index &= ~7UL;
244 hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
245 for (i = 0; i < 8; ++i) {
246 if ((*hpte & HPTE_V_VALID) == 0 &&
247 try_lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID |
248 HPTE_V_ABSENT))
249 break;
250 hpte += 2;
251 }
252 if (i == 8) {
253 /*
254 * Since try_lock_hpte doesn't retry (not even stdcx.
255 * failures), it could be that there is a free slot
256 * but we transiently failed to lock it. Try again,
257 * actually locking each slot and checking it.
258 */
259 hpte -= 16;
260 for (i = 0; i < 8; ++i) {
261 while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
262 cpu_relax();
263 if (!(*hpte & (HPTE_V_VALID | HPTE_V_ABSENT)))
264 break;
265 *hpte &= ~HPTE_V_HVLOCK;
266 hpte += 2;
267 }
268 if (i == 8)
269 return H_PTEG_FULL;
270 }
271 pte_index += i;
272 } else {
273 hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
274 if (!try_lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID |
275 HPTE_V_ABSENT)) {
276 /* Lock the slot and check again */
277 while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
278 cpu_relax();
279 if (*hpte & (HPTE_V_VALID | HPTE_V_ABSENT)) {
280 *hpte &= ~HPTE_V_HVLOCK;
281 return H_PTEG_FULL;
282 }
283 }
284 }
285
286 /* Save away the guest's idea of the second HPTE dword */
287 rev = &kvm->arch.revmap[pte_index];
288 if (realmode)
289 rev = real_vmalloc_addr(rev);
290 if (rev)
291 rev->guest_rpte = g_ptel;
292
293 /* Link HPTE into reverse-map chain */
294 if (pteh & HPTE_V_VALID) {
295 if (realmode)
296 rmap = real_vmalloc_addr(rmap);
297 lock_rmap(rmap);
298 /* Check for pending invalidations under the rmap chain lock */
299 if (kvm->arch.using_mmu_notifiers &&
300 mmu_notifier_retry(vcpu, mmu_seq)) {
301 /* inval in progress, write a non-present HPTE */
302 pteh |= HPTE_V_ABSENT;
303 pteh &= ~HPTE_V_VALID;
304 unlock_rmap(rmap);
305 } else {
306 kvmppc_add_revmap_chain(kvm, rev, rmap, pte_index,
307 realmode);
308 /* Only set R/C in real HPTE if already set in *rmap */
309 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
310 ptel &= rcbits | ~(HPTE_R_R | HPTE_R_C);
311 }
312 }
313
314 hpte[1] = ptel;
315
316 /* Write the first HPTE dword, unlocking the HPTE and making it valid */
317 eieio();
318 hpte[0] = pteh;
319 asm volatile("ptesync" : : : "memory");
320
321 vcpu->arch.gpr[4] = pte_index;
322 return H_SUCCESS;
323 }
324 EXPORT_SYMBOL_GPL(kvmppc_h_enter);
325
326 #define LOCK_TOKEN (*(u32 *)(&get_paca()->lock_token))
327
try_lock_tlbie(unsigned int * lock)328 static inline int try_lock_tlbie(unsigned int *lock)
329 {
330 unsigned int tmp, old;
331 unsigned int token = LOCK_TOKEN;
332
333 asm volatile("1:lwarx %1,0,%2\n"
334 " cmpwi cr0,%1,0\n"
335 " bne 2f\n"
336 " stwcx. %3,0,%2\n"
337 " bne- 1b\n"
338 " isync\n"
339 "2:"
340 : "=&r" (tmp), "=&r" (old)
341 : "r" (lock), "r" (token)
342 : "cc", "memory");
343 return old == 0;
344 }
345
kvmppc_h_remove(struct kvm_vcpu * vcpu,unsigned long flags,unsigned long pte_index,unsigned long avpn,unsigned long va)346 long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
347 unsigned long pte_index, unsigned long avpn,
348 unsigned long va)
349 {
350 struct kvm *kvm = vcpu->kvm;
351 unsigned long *hpte;
352 unsigned long v, r, rb;
353 struct revmap_entry *rev;
354
355 if (pte_index >= HPT_NPTE)
356 return H_PARAMETER;
357 hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
358 while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
359 cpu_relax();
360 if ((hpte[0] & (HPTE_V_ABSENT | HPTE_V_VALID)) == 0 ||
361 ((flags & H_AVPN) && (hpte[0] & ~0x7fUL) != avpn) ||
362 ((flags & H_ANDCOND) && (hpte[0] & avpn) != 0)) {
363 hpte[0] &= ~HPTE_V_HVLOCK;
364 return H_NOT_FOUND;
365 }
366
367 rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
368 v = hpte[0] & ~HPTE_V_HVLOCK;
369 if (v & HPTE_V_VALID) {
370 hpte[0] &= ~HPTE_V_VALID;
371 rb = compute_tlbie_rb(v, hpte[1], pte_index);
372 if (!(flags & H_LOCAL) && atomic_read(&kvm->online_vcpus) > 1) {
373 while (!try_lock_tlbie(&kvm->arch.tlbie_lock))
374 cpu_relax();
375 asm volatile("ptesync" : : : "memory");
376 asm volatile(PPC_TLBIE(%1,%0)"; eieio; tlbsync"
377 : : "r" (rb), "r" (kvm->arch.lpid));
378 asm volatile("ptesync" : : : "memory");
379 kvm->arch.tlbie_lock = 0;
380 } else {
381 asm volatile("ptesync" : : : "memory");
382 asm volatile("tlbiel %0" : : "r" (rb));
383 asm volatile("ptesync" : : : "memory");
384 }
385 /* Read PTE low word after tlbie to get final R/C values */
386 remove_revmap_chain(kvm, pte_index, rev, v, hpte[1]);
387 }
388 r = rev->guest_rpte;
389 unlock_hpte(hpte, 0);
390
391 vcpu->arch.gpr[4] = v;
392 vcpu->arch.gpr[5] = r;
393 return H_SUCCESS;
394 }
395
kvmppc_h_bulk_remove(struct kvm_vcpu * vcpu)396 long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
397 {
398 struct kvm *kvm = vcpu->kvm;
399 unsigned long *args = &vcpu->arch.gpr[4];
400 unsigned long *hp, *hptes[4], tlbrb[4];
401 long int i, j, k, n, found, indexes[4];
402 unsigned long flags, req, pte_index, rcbits;
403 long int local = 0;
404 long int ret = H_SUCCESS;
405 struct revmap_entry *rev, *revs[4];
406
407 if (atomic_read(&kvm->online_vcpus) == 1)
408 local = 1;
409 for (i = 0; i < 4 && ret == H_SUCCESS; ) {
410 n = 0;
411 for (; i < 4; ++i) {
412 j = i * 2;
413 pte_index = args[j];
414 flags = pte_index >> 56;
415 pte_index &= ((1ul << 56) - 1);
416 req = flags >> 6;
417 flags &= 3;
418 if (req == 3) { /* no more requests */
419 i = 4;
420 break;
421 }
422 if (req != 1 || flags == 3 || pte_index >= HPT_NPTE) {
423 /* parameter error */
424 args[j] = ((0xa0 | flags) << 56) + pte_index;
425 ret = H_PARAMETER;
426 break;
427 }
428 hp = (unsigned long *)
429 (kvm->arch.hpt_virt + (pte_index << 4));
430 /* to avoid deadlock, don't spin except for first */
431 if (!try_lock_hpte(hp, HPTE_V_HVLOCK)) {
432 if (n)
433 break;
434 while (!try_lock_hpte(hp, HPTE_V_HVLOCK))
435 cpu_relax();
436 }
437 found = 0;
438 if (hp[0] & (HPTE_V_ABSENT | HPTE_V_VALID)) {
439 switch (flags & 3) {
440 case 0: /* absolute */
441 found = 1;
442 break;
443 case 1: /* andcond */
444 if (!(hp[0] & args[j + 1]))
445 found = 1;
446 break;
447 case 2: /* AVPN */
448 if ((hp[0] & ~0x7fUL) == args[j + 1])
449 found = 1;
450 break;
451 }
452 }
453 if (!found) {
454 hp[0] &= ~HPTE_V_HVLOCK;
455 args[j] = ((0x90 | flags) << 56) + pte_index;
456 continue;
457 }
458
459 args[j] = ((0x80 | flags) << 56) + pte_index;
460 rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
461
462 if (!(hp[0] & HPTE_V_VALID)) {
463 /* insert R and C bits from PTE */
464 rcbits = rev->guest_rpte & (HPTE_R_R|HPTE_R_C);
465 args[j] |= rcbits << (56 - 5);
466 hp[0] = 0;
467 continue;
468 }
469
470 hp[0] &= ~HPTE_V_VALID; /* leave it locked */
471 tlbrb[n] = compute_tlbie_rb(hp[0], hp[1], pte_index);
472 indexes[n] = j;
473 hptes[n] = hp;
474 revs[n] = rev;
475 ++n;
476 }
477
478 if (!n)
479 break;
480
481 /* Now that we've collected a batch, do the tlbies */
482 if (!local) {
483 while(!try_lock_tlbie(&kvm->arch.tlbie_lock))
484 cpu_relax();
485 asm volatile("ptesync" : : : "memory");
486 for (k = 0; k < n; ++k)
487 asm volatile(PPC_TLBIE(%1,%0) : :
488 "r" (tlbrb[k]),
489 "r" (kvm->arch.lpid));
490 asm volatile("eieio; tlbsync; ptesync" : : : "memory");
491 kvm->arch.tlbie_lock = 0;
492 } else {
493 asm volatile("ptesync" : : : "memory");
494 for (k = 0; k < n; ++k)
495 asm volatile("tlbiel %0" : : "r" (tlbrb[k]));
496 asm volatile("ptesync" : : : "memory");
497 }
498
499 /* Read PTE low words after tlbie to get final R/C values */
500 for (k = 0; k < n; ++k) {
501 j = indexes[k];
502 pte_index = args[j] & ((1ul << 56) - 1);
503 hp = hptes[k];
504 rev = revs[k];
505 remove_revmap_chain(kvm, pte_index, rev, hp[0], hp[1]);
506 rcbits = rev->guest_rpte & (HPTE_R_R|HPTE_R_C);
507 args[j] |= rcbits << (56 - 5);
508 hp[0] = 0;
509 }
510 }
511
512 return ret;
513 }
514
kvmppc_h_protect(struct kvm_vcpu * vcpu,unsigned long flags,unsigned long pte_index,unsigned long avpn,unsigned long va)515 long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
516 unsigned long pte_index, unsigned long avpn,
517 unsigned long va)
518 {
519 struct kvm *kvm = vcpu->kvm;
520 unsigned long *hpte;
521 struct revmap_entry *rev;
522 unsigned long v, r, rb, mask, bits;
523
524 if (pte_index >= HPT_NPTE)
525 return H_PARAMETER;
526
527 hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
528 while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
529 cpu_relax();
530 if ((hpte[0] & (HPTE_V_ABSENT | HPTE_V_VALID)) == 0 ||
531 ((flags & H_AVPN) && (hpte[0] & ~0x7fUL) != avpn)) {
532 hpte[0] &= ~HPTE_V_HVLOCK;
533 return H_NOT_FOUND;
534 }
535
536 if (atomic_read(&kvm->online_vcpus) == 1)
537 flags |= H_LOCAL;
538 v = hpte[0];
539 bits = (flags << 55) & HPTE_R_PP0;
540 bits |= (flags << 48) & HPTE_R_KEY_HI;
541 bits |= flags & (HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_LO);
542
543 /* Update guest view of 2nd HPTE dword */
544 mask = HPTE_R_PP0 | HPTE_R_PP | HPTE_R_N |
545 HPTE_R_KEY_HI | HPTE_R_KEY_LO;
546 rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
547 if (rev) {
548 r = (rev->guest_rpte & ~mask) | bits;
549 rev->guest_rpte = r;
550 }
551 r = (hpte[1] & ~mask) | bits;
552
553 /* Update HPTE */
554 if (v & HPTE_V_VALID) {
555 rb = compute_tlbie_rb(v, r, pte_index);
556 hpte[0] = v & ~HPTE_V_VALID;
557 if (!(flags & H_LOCAL)) {
558 while(!try_lock_tlbie(&kvm->arch.tlbie_lock))
559 cpu_relax();
560 asm volatile("ptesync" : : : "memory");
561 asm volatile(PPC_TLBIE(%1,%0)"; eieio; tlbsync"
562 : : "r" (rb), "r" (kvm->arch.lpid));
563 asm volatile("ptesync" : : : "memory");
564 kvm->arch.tlbie_lock = 0;
565 } else {
566 asm volatile("ptesync" : : : "memory");
567 asm volatile("tlbiel %0" : : "r" (rb));
568 asm volatile("ptesync" : : : "memory");
569 }
570 }
571 hpte[1] = r;
572 eieio();
573 hpte[0] = v & ~HPTE_V_HVLOCK;
574 asm volatile("ptesync" : : : "memory");
575 return H_SUCCESS;
576 }
577
kvmppc_h_read(struct kvm_vcpu * vcpu,unsigned long flags,unsigned long pte_index)578 long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
579 unsigned long pte_index)
580 {
581 struct kvm *kvm = vcpu->kvm;
582 unsigned long *hpte, v, r;
583 int i, n = 1;
584 struct revmap_entry *rev = NULL;
585
586 if (pte_index >= HPT_NPTE)
587 return H_PARAMETER;
588 if (flags & H_READ_4) {
589 pte_index &= ~3;
590 n = 4;
591 }
592 rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
593 for (i = 0; i < n; ++i, ++pte_index) {
594 hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
595 v = hpte[0] & ~HPTE_V_HVLOCK;
596 r = hpte[1];
597 if (v & HPTE_V_ABSENT) {
598 v &= ~HPTE_V_ABSENT;
599 v |= HPTE_V_VALID;
600 }
601 if (v & HPTE_V_VALID)
602 r = rev[i].guest_rpte | (r & (HPTE_R_R | HPTE_R_C));
603 vcpu->arch.gpr[4 + i * 2] = v;
604 vcpu->arch.gpr[5 + i * 2] = r;
605 }
606 return H_SUCCESS;
607 }
608
kvmppc_invalidate_hpte(struct kvm * kvm,unsigned long * hptep,unsigned long pte_index)609 void kvmppc_invalidate_hpte(struct kvm *kvm, unsigned long *hptep,
610 unsigned long pte_index)
611 {
612 unsigned long rb;
613
614 hptep[0] &= ~HPTE_V_VALID;
615 rb = compute_tlbie_rb(hptep[0], hptep[1], pte_index);
616 while (!try_lock_tlbie(&kvm->arch.tlbie_lock))
617 cpu_relax();
618 asm volatile("ptesync" : : : "memory");
619 asm volatile(PPC_TLBIE(%1,%0)"; eieio; tlbsync"
620 : : "r" (rb), "r" (kvm->arch.lpid));
621 asm volatile("ptesync" : : : "memory");
622 kvm->arch.tlbie_lock = 0;
623 }
624 EXPORT_SYMBOL_GPL(kvmppc_invalidate_hpte);
625
kvmppc_clear_ref_hpte(struct kvm * kvm,unsigned long * hptep,unsigned long pte_index)626 void kvmppc_clear_ref_hpte(struct kvm *kvm, unsigned long *hptep,
627 unsigned long pte_index)
628 {
629 unsigned long rb;
630 unsigned char rbyte;
631
632 rb = compute_tlbie_rb(hptep[0], hptep[1], pte_index);
633 rbyte = (hptep[1] & ~HPTE_R_R) >> 8;
634 /* modify only the second-last byte, which contains the ref bit */
635 *((char *)hptep + 14) = rbyte;
636 while (!try_lock_tlbie(&kvm->arch.tlbie_lock))
637 cpu_relax();
638 asm volatile(PPC_TLBIE(%1,%0)"; eieio; tlbsync"
639 : : "r" (rb), "r" (kvm->arch.lpid));
640 asm volatile("ptesync" : : : "memory");
641 kvm->arch.tlbie_lock = 0;
642 }
643 EXPORT_SYMBOL_GPL(kvmppc_clear_ref_hpte);
644
645 static int slb_base_page_shift[4] = {
646 24, /* 16M */
647 16, /* 64k */
648 34, /* 16G */
649 20, /* 1M, unsupported */
650 };
651
652 /* When called from virtmode, this func should be protected by
653 * preempt_disable(), otherwise, the holding of HPTE_V_HVLOCK
654 * can trigger deadlock issue.
655 */
kvmppc_hv_find_lock_hpte(struct kvm * kvm,gva_t eaddr,unsigned long slb_v,unsigned long valid)656 long kvmppc_hv_find_lock_hpte(struct kvm *kvm, gva_t eaddr, unsigned long slb_v,
657 unsigned long valid)
658 {
659 unsigned int i;
660 unsigned int pshift;
661 unsigned long somask;
662 unsigned long vsid, hash;
663 unsigned long avpn;
664 unsigned long *hpte;
665 unsigned long mask, val;
666 unsigned long v, r;
667
668 /* Get page shift, work out hash and AVPN etc. */
669 mask = SLB_VSID_B | HPTE_V_AVPN | HPTE_V_SECONDARY;
670 val = 0;
671 pshift = 12;
672 if (slb_v & SLB_VSID_L) {
673 mask |= HPTE_V_LARGE;
674 val |= HPTE_V_LARGE;
675 pshift = slb_base_page_shift[(slb_v & SLB_VSID_LP) >> 4];
676 }
677 if (slb_v & SLB_VSID_B_1T) {
678 somask = (1UL << 40) - 1;
679 vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT_1T;
680 vsid ^= vsid << 25;
681 } else {
682 somask = (1UL << 28) - 1;
683 vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT;
684 }
685 hash = (vsid ^ ((eaddr & somask) >> pshift)) & HPT_HASH_MASK;
686 avpn = slb_v & ~(somask >> 16); /* also includes B */
687 avpn |= (eaddr & somask) >> 16;
688
689 if (pshift >= 24)
690 avpn &= ~((1UL << (pshift - 16)) - 1);
691 else
692 avpn &= ~0x7fUL;
693 val |= avpn;
694
695 for (;;) {
696 hpte = (unsigned long *)(kvm->arch.hpt_virt + (hash << 7));
697
698 for (i = 0; i < 16; i += 2) {
699 /* Read the PTE racily */
700 v = hpte[i] & ~HPTE_V_HVLOCK;
701
702 /* Check valid/absent, hash, segment size and AVPN */
703 if (!(v & valid) || (v & mask) != val)
704 continue;
705
706 /* Lock the PTE and read it under the lock */
707 while (!try_lock_hpte(&hpte[i], HPTE_V_HVLOCK))
708 cpu_relax();
709 v = hpte[i] & ~HPTE_V_HVLOCK;
710 r = hpte[i+1];
711
712 /*
713 * Check the HPTE again, including large page size
714 * Since we don't currently allow any MPSS (mixed
715 * page-size segment) page sizes, it is sufficient
716 * to check against the actual page size.
717 */
718 if ((v & valid) && (v & mask) == val &&
719 hpte_page_size(v, r) == (1ul << pshift))
720 /* Return with the HPTE still locked */
721 return (hash << 3) + (i >> 1);
722
723 /* Unlock and move on */
724 hpte[i] = v;
725 }
726
727 if (val & HPTE_V_SECONDARY)
728 break;
729 val |= HPTE_V_SECONDARY;
730 hash = hash ^ HPT_HASH_MASK;
731 }
732 return -1;
733 }
734 EXPORT_SYMBOL(kvmppc_hv_find_lock_hpte);
735
736 /*
737 * Called in real mode to check whether an HPTE not found fault
738 * is due to accessing a paged-out page or an emulated MMIO page,
739 * or if a protection fault is due to accessing a page that the
740 * guest wanted read/write access to but which we made read-only.
741 * Returns a possibly modified status (DSISR) value if not
742 * (i.e. pass the interrupt to the guest),
743 * -1 to pass the fault up to host kernel mode code, -2 to do that
744 * and also load the instruction word (for MMIO emulation),
745 * or 0 if we should make the guest retry the access.
746 */
kvmppc_hpte_hv_fault(struct kvm_vcpu * vcpu,unsigned long addr,unsigned long slb_v,unsigned int status,bool data)747 long kvmppc_hpte_hv_fault(struct kvm_vcpu *vcpu, unsigned long addr,
748 unsigned long slb_v, unsigned int status, bool data)
749 {
750 struct kvm *kvm = vcpu->kvm;
751 long int index;
752 unsigned long v, r, gr;
753 unsigned long *hpte;
754 unsigned long valid;
755 struct revmap_entry *rev;
756 unsigned long pp, key;
757
758 /* For protection fault, expect to find a valid HPTE */
759 valid = HPTE_V_VALID;
760 if (status & DSISR_NOHPTE)
761 valid |= HPTE_V_ABSENT;
762
763 index = kvmppc_hv_find_lock_hpte(kvm, addr, slb_v, valid);
764 if (index < 0) {
765 if (status & DSISR_NOHPTE)
766 return status; /* there really was no HPTE */
767 return 0; /* for prot fault, HPTE disappeared */
768 }
769 hpte = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
770 v = hpte[0] & ~HPTE_V_HVLOCK;
771 r = hpte[1];
772 rev = real_vmalloc_addr(&kvm->arch.revmap[index]);
773 gr = rev->guest_rpte;
774
775 unlock_hpte(hpte, v);
776
777 /* For not found, if the HPTE is valid by now, retry the instruction */
778 if ((status & DSISR_NOHPTE) && (v & HPTE_V_VALID))
779 return 0;
780
781 /* Check access permissions to the page */
782 pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
783 key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
784 status &= ~DSISR_NOHPTE; /* DSISR_NOHPTE == SRR1_ISI_NOPT */
785 if (!data) {
786 if (gr & (HPTE_R_N | HPTE_R_G))
787 return status | SRR1_ISI_N_OR_G;
788 if (!hpte_read_permission(pp, slb_v & key))
789 return status | SRR1_ISI_PROT;
790 } else if (status & DSISR_ISSTORE) {
791 /* check write permission */
792 if (!hpte_write_permission(pp, slb_v & key))
793 return status | DSISR_PROTFAULT;
794 } else {
795 if (!hpte_read_permission(pp, slb_v & key))
796 return status | DSISR_PROTFAULT;
797 }
798
799 /* Check storage key, if applicable */
800 if (data && (vcpu->arch.shregs.msr & MSR_DR)) {
801 unsigned int perm = hpte_get_skey_perm(gr, vcpu->arch.amr);
802 if (status & DSISR_ISSTORE)
803 perm >>= 1;
804 if (perm & 1)
805 return status | DSISR_KEYFAULT;
806 }
807
808 /* Save HPTE info for virtual-mode handler */
809 vcpu->arch.pgfault_addr = addr;
810 vcpu->arch.pgfault_index = index;
811 vcpu->arch.pgfault_hpte[0] = v;
812 vcpu->arch.pgfault_hpte[1] = r;
813
814 /* Check the storage key to see if it is possibly emulated MMIO */
815 if (data && (vcpu->arch.shregs.msr & MSR_IR) &&
816 (r & (HPTE_R_KEY_HI | HPTE_R_KEY_LO)) ==
817 (HPTE_R_KEY_HI | HPTE_R_KEY_LO))
818 return -2; /* MMIO emulation - load instr word */
819
820 return -1; /* send fault up to host kernel mode */
821 }
822