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 #include <linux/log2.h>
16 
17 #include <asm/tlbflush.h>
18 #include <asm/trace.h>
19 #include <asm/kvm_ppc.h>
20 #include <asm/kvm_book3s.h>
21 #include <asm/book3s/64/mmu-hash.h>
22 #include <asm/hvcall.h>
23 #include <asm/synch.h>
24 #include <asm/ppc-opcode.h>
25 #include <asm/pte-walk.h>
26 
27 /* Translate address of a vmalloc'd thing to a linear map address */
28 static void *real_vmalloc_addr(void *x)
29 {
30 	unsigned long addr = (unsigned long) x;
31 	pte_t *p;
32 	/*
33 	 * assume we don't have huge pages in vmalloc space...
34 	 * So don't worry about THP collapse/split. Called
35 	 * Only in realmode with MSR_EE = 0, hence won't need irq_save/restore.
36 	 */
37 	p = find_init_mm_pte(addr, NULL);
38 	if (!p || !pte_present(*p))
39 		return NULL;
40 	addr = (pte_pfn(*p) << PAGE_SHIFT) | (addr & ~PAGE_MASK);
41 	return __va(addr);
42 }
43 
44 /* Return 1 if we need to do a global tlbie, 0 if we can use tlbiel */
45 static int global_invalidates(struct kvm *kvm, unsigned long flags)
46 {
47 	int global;
48 	int cpu;
49 
50 	/*
51 	 * If there is only one vcore, and it's currently running,
52 	 * as indicated by local_paca->kvm_hstate.kvm_vcpu being set,
53 	 * we can use tlbiel as long as we mark all other physical
54 	 * cores as potentially having stale TLB entries for this lpid.
55 	 * Otherwise, don't use tlbiel.
56 	 */
57 	if (kvm->arch.online_vcores == 1 && local_paca->kvm_hstate.kvm_vcpu)
58 		global = 0;
59 	else
60 		global = 1;
61 
62 	if (!global) {
63 		/* any other core might now have stale TLB entries... */
64 		smp_wmb();
65 		cpumask_setall(&kvm->arch.need_tlb_flush);
66 		cpu = local_paca->kvm_hstate.kvm_vcore->pcpu;
67 		/*
68 		 * On POWER9, threads are independent but the TLB is shared,
69 		 * so use the bit for the first thread to represent the core.
70 		 */
71 		if (cpu_has_feature(CPU_FTR_ARCH_300))
72 			cpu = cpu_first_thread_sibling(cpu);
73 		cpumask_clear_cpu(cpu, &kvm->arch.need_tlb_flush);
74 	}
75 
76 	return global;
77 }
78 
79 /*
80  * Add this HPTE into the chain for the real page.
81  * Must be called with the chain locked; it unlocks the chain.
82  */
83 void kvmppc_add_revmap_chain(struct kvm *kvm, struct revmap_entry *rev,
84 			     unsigned long *rmap, long pte_index, int realmode)
85 {
86 	struct revmap_entry *head, *tail;
87 	unsigned long i;
88 
89 	if (*rmap & KVMPPC_RMAP_PRESENT) {
90 		i = *rmap & KVMPPC_RMAP_INDEX;
91 		head = &kvm->arch.hpt.rev[i];
92 		if (realmode)
93 			head = real_vmalloc_addr(head);
94 		tail = &kvm->arch.hpt.rev[head->back];
95 		if (realmode)
96 			tail = real_vmalloc_addr(tail);
97 		rev->forw = i;
98 		rev->back = head->back;
99 		tail->forw = pte_index;
100 		head->back = pte_index;
101 	} else {
102 		rev->forw = rev->back = pte_index;
103 		*rmap = (*rmap & ~KVMPPC_RMAP_INDEX) |
104 			pte_index | KVMPPC_RMAP_PRESENT;
105 	}
106 	unlock_rmap(rmap);
107 }
108 EXPORT_SYMBOL_GPL(kvmppc_add_revmap_chain);
109 
110 /* Update the dirty bitmap of a memslot */
111 void kvmppc_update_dirty_map(struct kvm_memory_slot *memslot,
112 			     unsigned long gfn, unsigned long psize)
113 {
114 	unsigned long npages;
115 
116 	if (!psize || !memslot->dirty_bitmap)
117 		return;
118 	npages = (psize + PAGE_SIZE - 1) / PAGE_SIZE;
119 	gfn -= memslot->base_gfn;
120 	set_dirty_bits_atomic(memslot->dirty_bitmap, gfn, npages);
121 }
122 EXPORT_SYMBOL_GPL(kvmppc_update_dirty_map);
123 
124 static void kvmppc_set_dirty_from_hpte(struct kvm *kvm,
125 				unsigned long hpte_v, unsigned long hpte_gr)
126 {
127 	struct kvm_memory_slot *memslot;
128 	unsigned long gfn;
129 	unsigned long psize;
130 
131 	psize = kvmppc_actual_pgsz(hpte_v, hpte_gr);
132 	gfn = hpte_rpn(hpte_gr, psize);
133 	memslot = __gfn_to_memslot(kvm_memslots_raw(kvm), gfn);
134 	if (memslot && memslot->dirty_bitmap)
135 		kvmppc_update_dirty_map(memslot, gfn, psize);
136 }
137 
138 /* Returns a pointer to the revmap entry for the page mapped by a HPTE */
139 static unsigned long *revmap_for_hpte(struct kvm *kvm, unsigned long hpte_v,
140 				      unsigned long hpte_gr,
141 				      struct kvm_memory_slot **memslotp,
142 				      unsigned long *gfnp)
143 {
144 	struct kvm_memory_slot *memslot;
145 	unsigned long *rmap;
146 	unsigned long gfn;
147 
148 	gfn = hpte_rpn(hpte_gr, kvmppc_actual_pgsz(hpte_v, hpte_gr));
149 	memslot = __gfn_to_memslot(kvm_memslots_raw(kvm), gfn);
150 	if (memslotp)
151 		*memslotp = memslot;
152 	if (gfnp)
153 		*gfnp = gfn;
154 	if (!memslot)
155 		return NULL;
156 
157 	rmap = real_vmalloc_addr(&memslot->arch.rmap[gfn - memslot->base_gfn]);
158 	return rmap;
159 }
160 
161 /* Remove this HPTE from the chain for a real page */
162 static void remove_revmap_chain(struct kvm *kvm, long pte_index,
163 				struct revmap_entry *rev,
164 				unsigned long hpte_v, unsigned long hpte_r)
165 {
166 	struct revmap_entry *next, *prev;
167 	unsigned long ptel, head;
168 	unsigned long *rmap;
169 	unsigned long rcbits;
170 	struct kvm_memory_slot *memslot;
171 	unsigned long gfn;
172 
173 	rcbits = hpte_r & (HPTE_R_R | HPTE_R_C);
174 	ptel = rev->guest_rpte |= rcbits;
175 	rmap = revmap_for_hpte(kvm, hpte_v, ptel, &memslot, &gfn);
176 	if (!rmap)
177 		return;
178 	lock_rmap(rmap);
179 
180 	head = *rmap & KVMPPC_RMAP_INDEX;
181 	next = real_vmalloc_addr(&kvm->arch.hpt.rev[rev->forw]);
182 	prev = real_vmalloc_addr(&kvm->arch.hpt.rev[rev->back]);
183 	next->back = rev->back;
184 	prev->forw = rev->forw;
185 	if (head == pte_index) {
186 		head = rev->forw;
187 		if (head == pte_index)
188 			*rmap &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
189 		else
190 			*rmap = (*rmap & ~KVMPPC_RMAP_INDEX) | head;
191 	}
192 	*rmap |= rcbits << KVMPPC_RMAP_RC_SHIFT;
193 	if (rcbits & HPTE_R_C)
194 		kvmppc_update_dirty_map(memslot, gfn,
195 					kvmppc_actual_pgsz(hpte_v, hpte_r));
196 	unlock_rmap(rmap);
197 }
198 
199 long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
200 		       long pte_index, unsigned long pteh, unsigned long ptel,
201 		       pgd_t *pgdir, bool realmode, unsigned long *pte_idx_ret)
202 {
203 	unsigned long i, pa, gpa, gfn, psize;
204 	unsigned long slot_fn, hva;
205 	__be64 *hpte;
206 	struct revmap_entry *rev;
207 	unsigned long g_ptel;
208 	struct kvm_memory_slot *memslot;
209 	unsigned hpage_shift;
210 	bool is_ci;
211 	unsigned long *rmap;
212 	pte_t *ptep;
213 	unsigned int writing;
214 	unsigned long mmu_seq;
215 	unsigned long rcbits, irq_flags = 0;
216 
217 	if (kvm_is_radix(kvm))
218 		return H_FUNCTION;
219 	psize = kvmppc_actual_pgsz(pteh, ptel);
220 	if (!psize)
221 		return H_PARAMETER;
222 	writing = hpte_is_writable(ptel);
223 	pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID);
224 	ptel &= ~HPTE_GR_RESERVED;
225 	g_ptel = ptel;
226 
227 	/* used later to detect if we might have been invalidated */
228 	mmu_seq = kvm->mmu_notifier_seq;
229 	smp_rmb();
230 
231 	/* Find the memslot (if any) for this address */
232 	gpa = (ptel & HPTE_R_RPN) & ~(psize - 1);
233 	gfn = gpa >> PAGE_SHIFT;
234 	memslot = __gfn_to_memslot(kvm_memslots_raw(kvm), gfn);
235 	pa = 0;
236 	is_ci = false;
237 	rmap = NULL;
238 	if (!(memslot && !(memslot->flags & KVM_MEMSLOT_INVALID))) {
239 		/* Emulated MMIO - mark this with key=31 */
240 		pteh |= HPTE_V_ABSENT;
241 		ptel |= HPTE_R_KEY_HI | HPTE_R_KEY_LO;
242 		goto do_insert;
243 	}
244 
245 	/* Check if the requested page fits entirely in the memslot. */
246 	if (!slot_is_aligned(memslot, psize))
247 		return H_PARAMETER;
248 	slot_fn = gfn - memslot->base_gfn;
249 	rmap = &memslot->arch.rmap[slot_fn];
250 
251 	/* Translate to host virtual address */
252 	hva = __gfn_to_hva_memslot(memslot, gfn);
253 	/*
254 	 * If we had a page table table change after lookup, we would
255 	 * retry via mmu_notifier_retry.
256 	 */
257 	if (!realmode)
258 		local_irq_save(irq_flags);
259 	/*
260 	 * If called in real mode we have MSR_EE = 0. Otherwise
261 	 * we disable irq above.
262 	 */
263 	ptep = __find_linux_pte(pgdir, hva, NULL, &hpage_shift);
264 	if (ptep) {
265 		pte_t pte;
266 		unsigned int host_pte_size;
267 
268 		if (hpage_shift)
269 			host_pte_size = 1ul << hpage_shift;
270 		else
271 			host_pte_size = PAGE_SIZE;
272 		/*
273 		 * We should always find the guest page size
274 		 * to <= host page size, if host is using hugepage
275 		 */
276 		if (host_pte_size < psize) {
277 			if (!realmode)
278 				local_irq_restore(flags);
279 			return H_PARAMETER;
280 		}
281 		pte = kvmppc_read_update_linux_pte(ptep, writing);
282 		if (pte_present(pte) && !pte_protnone(pte)) {
283 			if (writing && !__pte_write(pte))
284 				/* make the actual HPTE be read-only */
285 				ptel = hpte_make_readonly(ptel);
286 			is_ci = pte_ci(pte);
287 			pa = pte_pfn(pte) << PAGE_SHIFT;
288 			pa |= hva & (host_pte_size - 1);
289 			pa |= gpa & ~PAGE_MASK;
290 		}
291 	}
292 	if (!realmode)
293 		local_irq_restore(irq_flags);
294 
295 	ptel &= HPTE_R_KEY | HPTE_R_PP0 | (psize-1);
296 	ptel |= pa;
297 
298 	if (pa)
299 		pteh |= HPTE_V_VALID;
300 	else {
301 		pteh |= HPTE_V_ABSENT;
302 		ptel &= ~(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
303 	}
304 
305 	/*If we had host pte mapping then  Check WIMG */
306 	if (ptep && !hpte_cache_flags_ok(ptel, is_ci)) {
307 		if (is_ci)
308 			return H_PARAMETER;
309 		/*
310 		 * Allow guest to map emulated device memory as
311 		 * uncacheable, but actually make it cacheable.
312 		 */
313 		ptel &= ~(HPTE_R_W|HPTE_R_I|HPTE_R_G);
314 		ptel |= HPTE_R_M;
315 	}
316 
317 	/* Find and lock the HPTEG slot to use */
318  do_insert:
319 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
320 		return H_PARAMETER;
321 	if (likely((flags & H_EXACT) == 0)) {
322 		pte_index &= ~7UL;
323 		hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
324 		for (i = 0; i < 8; ++i) {
325 			if ((be64_to_cpu(*hpte) & HPTE_V_VALID) == 0 &&
326 			    try_lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID |
327 					  HPTE_V_ABSENT))
328 				break;
329 			hpte += 2;
330 		}
331 		if (i == 8) {
332 			/*
333 			 * Since try_lock_hpte doesn't retry (not even stdcx.
334 			 * failures), it could be that there is a free slot
335 			 * but we transiently failed to lock it.  Try again,
336 			 * actually locking each slot and checking it.
337 			 */
338 			hpte -= 16;
339 			for (i = 0; i < 8; ++i) {
340 				u64 pte;
341 				while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
342 					cpu_relax();
343 				pte = be64_to_cpu(hpte[0]);
344 				if (!(pte & (HPTE_V_VALID | HPTE_V_ABSENT)))
345 					break;
346 				__unlock_hpte(hpte, pte);
347 				hpte += 2;
348 			}
349 			if (i == 8)
350 				return H_PTEG_FULL;
351 		}
352 		pte_index += i;
353 	} else {
354 		hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
355 		if (!try_lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID |
356 				   HPTE_V_ABSENT)) {
357 			/* Lock the slot and check again */
358 			u64 pte;
359 
360 			while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
361 				cpu_relax();
362 			pte = be64_to_cpu(hpte[0]);
363 			if (pte & (HPTE_V_VALID | HPTE_V_ABSENT)) {
364 				__unlock_hpte(hpte, pte);
365 				return H_PTEG_FULL;
366 			}
367 		}
368 	}
369 
370 	/* Save away the guest's idea of the second HPTE dword */
371 	rev = &kvm->arch.hpt.rev[pte_index];
372 	if (realmode)
373 		rev = real_vmalloc_addr(rev);
374 	if (rev) {
375 		rev->guest_rpte = g_ptel;
376 		note_hpte_modification(kvm, rev);
377 	}
378 
379 	/* Link HPTE into reverse-map chain */
380 	if (pteh & HPTE_V_VALID) {
381 		if (realmode)
382 			rmap = real_vmalloc_addr(rmap);
383 		lock_rmap(rmap);
384 		/* Check for pending invalidations under the rmap chain lock */
385 		if (mmu_notifier_retry(kvm, mmu_seq)) {
386 			/* inval in progress, write a non-present HPTE */
387 			pteh |= HPTE_V_ABSENT;
388 			pteh &= ~HPTE_V_VALID;
389 			ptel &= ~(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
390 			unlock_rmap(rmap);
391 		} else {
392 			kvmppc_add_revmap_chain(kvm, rev, rmap, pte_index,
393 						realmode);
394 			/* Only set R/C in real HPTE if already set in *rmap */
395 			rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
396 			ptel &= rcbits | ~(HPTE_R_R | HPTE_R_C);
397 		}
398 	}
399 
400 	/* Convert to new format on P9 */
401 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
402 		ptel = hpte_old_to_new_r(pteh, ptel);
403 		pteh = hpte_old_to_new_v(pteh);
404 	}
405 	hpte[1] = cpu_to_be64(ptel);
406 
407 	/* Write the first HPTE dword, unlocking the HPTE and making it valid */
408 	eieio();
409 	__unlock_hpte(hpte, pteh);
410 	asm volatile("ptesync" : : : "memory");
411 
412 	*pte_idx_ret = pte_index;
413 	return H_SUCCESS;
414 }
415 EXPORT_SYMBOL_GPL(kvmppc_do_h_enter);
416 
417 long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
418 		    long pte_index, unsigned long pteh, unsigned long ptel)
419 {
420 	return kvmppc_do_h_enter(vcpu->kvm, flags, pte_index, pteh, ptel,
421 				 vcpu->arch.pgdir, true, &vcpu->arch.gpr[4]);
422 }
423 
424 #ifdef __BIG_ENDIAN__
425 #define LOCK_TOKEN	(*(u32 *)(&get_paca()->lock_token))
426 #else
427 #define LOCK_TOKEN	(*(u32 *)(&get_paca()->paca_index))
428 #endif
429 
430 static inline int is_mmio_hpte(unsigned long v, unsigned long r)
431 {
432 	return ((v & HPTE_V_ABSENT) &&
433 		(r & (HPTE_R_KEY_HI | HPTE_R_KEY_LO)) ==
434 		(HPTE_R_KEY_HI | HPTE_R_KEY_LO));
435 }
436 
437 static inline int try_lock_tlbie(unsigned int *lock)
438 {
439 	unsigned int tmp, old;
440 	unsigned int token = LOCK_TOKEN;
441 
442 	asm volatile("1:lwarx	%1,0,%2\n"
443 		     "	cmpwi	cr0,%1,0\n"
444 		     "	bne	2f\n"
445 		     "  stwcx.	%3,0,%2\n"
446 		     "	bne-	1b\n"
447 		     "  isync\n"
448 		     "2:"
449 		     : "=&r" (tmp), "=&r" (old)
450 		     : "r" (lock), "r" (token)
451 		     : "cc", "memory");
452 	return old == 0;
453 }
454 
455 static void do_tlbies(struct kvm *kvm, unsigned long *rbvalues,
456 		      long npages, int global, bool need_sync)
457 {
458 	long i;
459 
460 	/*
461 	 * We use the POWER9 5-operand versions of tlbie and tlbiel here.
462 	 * Since we are using RIC=0 PRS=0 R=0, and P7/P8 tlbiel ignores
463 	 * the RS field, this is backwards-compatible with P7 and P8.
464 	 */
465 	if (global) {
466 		while (!try_lock_tlbie(&kvm->arch.tlbie_lock))
467 			cpu_relax();
468 		if (need_sync)
469 			asm volatile("ptesync" : : : "memory");
470 		for (i = 0; i < npages; ++i) {
471 			asm volatile(PPC_TLBIE_5(%0,%1,0,0,0) : :
472 				     "r" (rbvalues[i]), "r" (kvm->arch.lpid));
473 			trace_tlbie(kvm->arch.lpid, 0, rbvalues[i],
474 				kvm->arch.lpid, 0, 0, 0);
475 		}
476 		asm volatile("eieio; tlbsync; ptesync" : : : "memory");
477 		kvm->arch.tlbie_lock = 0;
478 	} else {
479 		if (need_sync)
480 			asm volatile("ptesync" : : : "memory");
481 		for (i = 0; i < npages; ++i) {
482 			asm volatile(PPC_TLBIEL(%0,%1,0,0,0) : :
483 				     "r" (rbvalues[i]), "r" (0));
484 			trace_tlbie(kvm->arch.lpid, 1, rbvalues[i],
485 				0, 0, 0, 0);
486 		}
487 		asm volatile("ptesync" : : : "memory");
488 	}
489 }
490 
491 long kvmppc_do_h_remove(struct kvm *kvm, unsigned long flags,
492 			unsigned long pte_index, unsigned long avpn,
493 			unsigned long *hpret)
494 {
495 	__be64 *hpte;
496 	unsigned long v, r, rb;
497 	struct revmap_entry *rev;
498 	u64 pte, orig_pte, pte_r;
499 
500 	if (kvm_is_radix(kvm))
501 		return H_FUNCTION;
502 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
503 		return H_PARAMETER;
504 	hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
505 	while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
506 		cpu_relax();
507 	pte = orig_pte = be64_to_cpu(hpte[0]);
508 	pte_r = be64_to_cpu(hpte[1]);
509 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
510 		pte = hpte_new_to_old_v(pte, pte_r);
511 		pte_r = hpte_new_to_old_r(pte_r);
512 	}
513 	if ((pte & (HPTE_V_ABSENT | HPTE_V_VALID)) == 0 ||
514 	    ((flags & H_AVPN) && (pte & ~0x7fUL) != avpn) ||
515 	    ((flags & H_ANDCOND) && (pte & avpn) != 0)) {
516 		__unlock_hpte(hpte, orig_pte);
517 		return H_NOT_FOUND;
518 	}
519 
520 	rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
521 	v = pte & ~HPTE_V_HVLOCK;
522 	if (v & HPTE_V_VALID) {
523 		hpte[0] &= ~cpu_to_be64(HPTE_V_VALID);
524 		rb = compute_tlbie_rb(v, pte_r, pte_index);
525 		do_tlbies(kvm, &rb, 1, global_invalidates(kvm, flags), true);
526 		/*
527 		 * The reference (R) and change (C) bits in a HPT
528 		 * entry can be set by hardware at any time up until
529 		 * the HPTE is invalidated and the TLB invalidation
530 		 * sequence has completed.  This means that when
531 		 * removing a HPTE, we need to re-read the HPTE after
532 		 * the invalidation sequence has completed in order to
533 		 * obtain reliable values of R and C.
534 		 */
535 		remove_revmap_chain(kvm, pte_index, rev, v,
536 				    be64_to_cpu(hpte[1]));
537 	}
538 	r = rev->guest_rpte & ~HPTE_GR_RESERVED;
539 	note_hpte_modification(kvm, rev);
540 	unlock_hpte(hpte, 0);
541 
542 	if (is_mmio_hpte(v, pte_r))
543 		atomic64_inc(&kvm->arch.mmio_update);
544 
545 	if (v & HPTE_V_ABSENT)
546 		v = (v & ~HPTE_V_ABSENT) | HPTE_V_VALID;
547 	hpret[0] = v;
548 	hpret[1] = r;
549 	return H_SUCCESS;
550 }
551 EXPORT_SYMBOL_GPL(kvmppc_do_h_remove);
552 
553 long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
554 		     unsigned long pte_index, unsigned long avpn)
555 {
556 	return kvmppc_do_h_remove(vcpu->kvm, flags, pte_index, avpn,
557 				  &vcpu->arch.gpr[4]);
558 }
559 
560 long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
561 {
562 	struct kvm *kvm = vcpu->kvm;
563 	unsigned long *args = &vcpu->arch.gpr[4];
564 	__be64 *hp, *hptes[4];
565 	unsigned long tlbrb[4];
566 	long int i, j, k, n, found, indexes[4];
567 	unsigned long flags, req, pte_index, rcbits;
568 	int global;
569 	long int ret = H_SUCCESS;
570 	struct revmap_entry *rev, *revs[4];
571 	u64 hp0, hp1;
572 
573 	if (kvm_is_radix(kvm))
574 		return H_FUNCTION;
575 	global = global_invalidates(kvm, 0);
576 	for (i = 0; i < 4 && ret == H_SUCCESS; ) {
577 		n = 0;
578 		for (; i < 4; ++i) {
579 			j = i * 2;
580 			pte_index = args[j];
581 			flags = pte_index >> 56;
582 			pte_index &= ((1ul << 56) - 1);
583 			req = flags >> 6;
584 			flags &= 3;
585 			if (req == 3) {		/* no more requests */
586 				i = 4;
587 				break;
588 			}
589 			if (req != 1 || flags == 3 ||
590 			    pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt)) {
591 				/* parameter error */
592 				args[j] = ((0xa0 | flags) << 56) + pte_index;
593 				ret = H_PARAMETER;
594 				break;
595 			}
596 			hp = (__be64 *) (kvm->arch.hpt.virt + (pte_index << 4));
597 			/* to avoid deadlock, don't spin except for first */
598 			if (!try_lock_hpte(hp, HPTE_V_HVLOCK)) {
599 				if (n)
600 					break;
601 				while (!try_lock_hpte(hp, HPTE_V_HVLOCK))
602 					cpu_relax();
603 			}
604 			found = 0;
605 			hp0 = be64_to_cpu(hp[0]);
606 			hp1 = be64_to_cpu(hp[1]);
607 			if (cpu_has_feature(CPU_FTR_ARCH_300)) {
608 				hp0 = hpte_new_to_old_v(hp0, hp1);
609 				hp1 = hpte_new_to_old_r(hp1);
610 			}
611 			if (hp0 & (HPTE_V_ABSENT | HPTE_V_VALID)) {
612 				switch (flags & 3) {
613 				case 0:		/* absolute */
614 					found = 1;
615 					break;
616 				case 1:		/* andcond */
617 					if (!(hp0 & args[j + 1]))
618 						found = 1;
619 					break;
620 				case 2:		/* AVPN */
621 					if ((hp0 & ~0x7fUL) == args[j + 1])
622 						found = 1;
623 					break;
624 				}
625 			}
626 			if (!found) {
627 				hp[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
628 				args[j] = ((0x90 | flags) << 56) + pte_index;
629 				continue;
630 			}
631 
632 			args[j] = ((0x80 | flags) << 56) + pte_index;
633 			rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
634 			note_hpte_modification(kvm, rev);
635 
636 			if (!(hp0 & HPTE_V_VALID)) {
637 				/* insert R and C bits from PTE */
638 				rcbits = rev->guest_rpte & (HPTE_R_R|HPTE_R_C);
639 				args[j] |= rcbits << (56 - 5);
640 				hp[0] = 0;
641 				if (is_mmio_hpte(hp0, hp1))
642 					atomic64_inc(&kvm->arch.mmio_update);
643 				continue;
644 			}
645 
646 			/* leave it locked */
647 			hp[0] &= ~cpu_to_be64(HPTE_V_VALID);
648 			tlbrb[n] = compute_tlbie_rb(hp0, hp1, pte_index);
649 			indexes[n] = j;
650 			hptes[n] = hp;
651 			revs[n] = rev;
652 			++n;
653 		}
654 
655 		if (!n)
656 			break;
657 
658 		/* Now that we've collected a batch, do the tlbies */
659 		do_tlbies(kvm, tlbrb, n, global, true);
660 
661 		/* Read PTE low words after tlbie to get final R/C values */
662 		for (k = 0; k < n; ++k) {
663 			j = indexes[k];
664 			pte_index = args[j] & ((1ul << 56) - 1);
665 			hp = hptes[k];
666 			rev = revs[k];
667 			remove_revmap_chain(kvm, pte_index, rev,
668 				be64_to_cpu(hp[0]), be64_to_cpu(hp[1]));
669 			rcbits = rev->guest_rpte & (HPTE_R_R|HPTE_R_C);
670 			args[j] |= rcbits << (56 - 5);
671 			__unlock_hpte(hp, 0);
672 		}
673 	}
674 
675 	return ret;
676 }
677 
678 long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
679 		      unsigned long pte_index, unsigned long avpn,
680 		      unsigned long va)
681 {
682 	struct kvm *kvm = vcpu->kvm;
683 	__be64 *hpte;
684 	struct revmap_entry *rev;
685 	unsigned long v, r, rb, mask, bits;
686 	u64 pte_v, pte_r;
687 
688 	if (kvm_is_radix(kvm))
689 		return H_FUNCTION;
690 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
691 		return H_PARAMETER;
692 
693 	hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
694 	while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
695 		cpu_relax();
696 	v = pte_v = be64_to_cpu(hpte[0]);
697 	if (cpu_has_feature(CPU_FTR_ARCH_300))
698 		v = hpte_new_to_old_v(v, be64_to_cpu(hpte[1]));
699 	if ((v & (HPTE_V_ABSENT | HPTE_V_VALID)) == 0 ||
700 	    ((flags & H_AVPN) && (v & ~0x7fUL) != avpn)) {
701 		__unlock_hpte(hpte, pte_v);
702 		return H_NOT_FOUND;
703 	}
704 
705 	pte_r = be64_to_cpu(hpte[1]);
706 	bits = (flags << 55) & HPTE_R_PP0;
707 	bits |= (flags << 48) & HPTE_R_KEY_HI;
708 	bits |= flags & (HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_LO);
709 
710 	/* Update guest view of 2nd HPTE dword */
711 	mask = HPTE_R_PP0 | HPTE_R_PP | HPTE_R_N |
712 		HPTE_R_KEY_HI | HPTE_R_KEY_LO;
713 	rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
714 	if (rev) {
715 		r = (rev->guest_rpte & ~mask) | bits;
716 		rev->guest_rpte = r;
717 		note_hpte_modification(kvm, rev);
718 	}
719 
720 	/* Update HPTE */
721 	if (v & HPTE_V_VALID) {
722 		/*
723 		 * If the page is valid, don't let it transition from
724 		 * readonly to writable.  If it should be writable, we'll
725 		 * take a trap and let the page fault code sort it out.
726 		 */
727 		r = (pte_r & ~mask) | bits;
728 		if (hpte_is_writable(r) && !hpte_is_writable(pte_r))
729 			r = hpte_make_readonly(r);
730 		/* If the PTE is changing, invalidate it first */
731 		if (r != pte_r) {
732 			rb = compute_tlbie_rb(v, r, pte_index);
733 			hpte[0] = cpu_to_be64((pte_v & ~HPTE_V_VALID) |
734 					      HPTE_V_ABSENT);
735 			do_tlbies(kvm, &rb, 1, global_invalidates(kvm, flags),
736 				  true);
737 			/* Don't lose R/C bit updates done by hardware */
738 			r |= be64_to_cpu(hpte[1]) & (HPTE_R_R | HPTE_R_C);
739 			hpte[1] = cpu_to_be64(r);
740 		}
741 	}
742 	unlock_hpte(hpte, pte_v & ~HPTE_V_HVLOCK);
743 	asm volatile("ptesync" : : : "memory");
744 	if (is_mmio_hpte(v, pte_r))
745 		atomic64_inc(&kvm->arch.mmio_update);
746 
747 	return H_SUCCESS;
748 }
749 
750 long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
751 		   unsigned long pte_index)
752 {
753 	struct kvm *kvm = vcpu->kvm;
754 	__be64 *hpte;
755 	unsigned long v, r;
756 	int i, n = 1;
757 	struct revmap_entry *rev = NULL;
758 
759 	if (kvm_is_radix(kvm))
760 		return H_FUNCTION;
761 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
762 		return H_PARAMETER;
763 	if (flags & H_READ_4) {
764 		pte_index &= ~3;
765 		n = 4;
766 	}
767 	rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
768 	for (i = 0; i < n; ++i, ++pte_index) {
769 		hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
770 		v = be64_to_cpu(hpte[0]) & ~HPTE_V_HVLOCK;
771 		r = be64_to_cpu(hpte[1]);
772 		if (cpu_has_feature(CPU_FTR_ARCH_300)) {
773 			v = hpte_new_to_old_v(v, r);
774 			r = hpte_new_to_old_r(r);
775 		}
776 		if (v & HPTE_V_ABSENT) {
777 			v &= ~HPTE_V_ABSENT;
778 			v |= HPTE_V_VALID;
779 		}
780 		if (v & HPTE_V_VALID) {
781 			r = rev[i].guest_rpte | (r & (HPTE_R_R | HPTE_R_C));
782 			r &= ~HPTE_GR_RESERVED;
783 		}
784 		vcpu->arch.gpr[4 + i * 2] = v;
785 		vcpu->arch.gpr[5 + i * 2] = r;
786 	}
787 	return H_SUCCESS;
788 }
789 
790 long kvmppc_h_clear_ref(struct kvm_vcpu *vcpu, unsigned long flags,
791 			unsigned long pte_index)
792 {
793 	struct kvm *kvm = vcpu->kvm;
794 	__be64 *hpte;
795 	unsigned long v, r, gr;
796 	struct revmap_entry *rev;
797 	unsigned long *rmap;
798 	long ret = H_NOT_FOUND;
799 
800 	if (kvm_is_radix(kvm))
801 		return H_FUNCTION;
802 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
803 		return H_PARAMETER;
804 
805 	rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
806 	hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
807 	while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
808 		cpu_relax();
809 	v = be64_to_cpu(hpte[0]);
810 	r = be64_to_cpu(hpte[1]);
811 	if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
812 		goto out;
813 
814 	gr = rev->guest_rpte;
815 	if (rev->guest_rpte & HPTE_R_R) {
816 		rev->guest_rpte &= ~HPTE_R_R;
817 		note_hpte_modification(kvm, rev);
818 	}
819 	if (v & HPTE_V_VALID) {
820 		gr |= r & (HPTE_R_R | HPTE_R_C);
821 		if (r & HPTE_R_R) {
822 			kvmppc_clear_ref_hpte(kvm, hpte, pte_index);
823 			rmap = revmap_for_hpte(kvm, v, gr, NULL, NULL);
824 			if (rmap) {
825 				lock_rmap(rmap);
826 				*rmap |= KVMPPC_RMAP_REFERENCED;
827 				unlock_rmap(rmap);
828 			}
829 		}
830 	}
831 	vcpu->arch.gpr[4] = gr;
832 	ret = H_SUCCESS;
833  out:
834 	unlock_hpte(hpte, v & ~HPTE_V_HVLOCK);
835 	return ret;
836 }
837 
838 long kvmppc_h_clear_mod(struct kvm_vcpu *vcpu, unsigned long flags,
839 			unsigned long pte_index)
840 {
841 	struct kvm *kvm = vcpu->kvm;
842 	__be64 *hpte;
843 	unsigned long v, r, gr;
844 	struct revmap_entry *rev;
845 	long ret = H_NOT_FOUND;
846 
847 	if (kvm_is_radix(kvm))
848 		return H_FUNCTION;
849 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
850 		return H_PARAMETER;
851 
852 	rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
853 	hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
854 	while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
855 		cpu_relax();
856 	v = be64_to_cpu(hpte[0]);
857 	r = be64_to_cpu(hpte[1]);
858 	if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
859 		goto out;
860 
861 	gr = rev->guest_rpte;
862 	if (gr & HPTE_R_C) {
863 		rev->guest_rpte &= ~HPTE_R_C;
864 		note_hpte_modification(kvm, rev);
865 	}
866 	if (v & HPTE_V_VALID) {
867 		/* need to make it temporarily absent so C is stable */
868 		hpte[0] |= cpu_to_be64(HPTE_V_ABSENT);
869 		kvmppc_invalidate_hpte(kvm, hpte, pte_index);
870 		r = be64_to_cpu(hpte[1]);
871 		gr |= r & (HPTE_R_R | HPTE_R_C);
872 		if (r & HPTE_R_C) {
873 			hpte[1] = cpu_to_be64(r & ~HPTE_R_C);
874 			eieio();
875 			kvmppc_set_dirty_from_hpte(kvm, v, gr);
876 		}
877 	}
878 	vcpu->arch.gpr[4] = gr;
879 	ret = H_SUCCESS;
880  out:
881 	unlock_hpte(hpte, v & ~HPTE_V_HVLOCK);
882 	return ret;
883 }
884 
885 void kvmppc_invalidate_hpte(struct kvm *kvm, __be64 *hptep,
886 			unsigned long pte_index)
887 {
888 	unsigned long rb;
889 	u64 hp0, hp1;
890 
891 	hptep[0] &= ~cpu_to_be64(HPTE_V_VALID);
892 	hp0 = be64_to_cpu(hptep[0]);
893 	hp1 = be64_to_cpu(hptep[1]);
894 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
895 		hp0 = hpte_new_to_old_v(hp0, hp1);
896 		hp1 = hpte_new_to_old_r(hp1);
897 	}
898 	rb = compute_tlbie_rb(hp0, hp1, pte_index);
899 	do_tlbies(kvm, &rb, 1, 1, true);
900 }
901 EXPORT_SYMBOL_GPL(kvmppc_invalidate_hpte);
902 
903 void kvmppc_clear_ref_hpte(struct kvm *kvm, __be64 *hptep,
904 			   unsigned long pte_index)
905 {
906 	unsigned long rb;
907 	unsigned char rbyte;
908 	u64 hp0, hp1;
909 
910 	hp0 = be64_to_cpu(hptep[0]);
911 	hp1 = be64_to_cpu(hptep[1]);
912 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
913 		hp0 = hpte_new_to_old_v(hp0, hp1);
914 		hp1 = hpte_new_to_old_r(hp1);
915 	}
916 	rb = compute_tlbie_rb(hp0, hp1, pte_index);
917 	rbyte = (be64_to_cpu(hptep[1]) & ~HPTE_R_R) >> 8;
918 	/* modify only the second-last byte, which contains the ref bit */
919 	*((char *)hptep + 14) = rbyte;
920 	do_tlbies(kvm, &rb, 1, 1, false);
921 }
922 EXPORT_SYMBOL_GPL(kvmppc_clear_ref_hpte);
923 
924 static int slb_base_page_shift[4] = {
925 	24,	/* 16M */
926 	16,	/* 64k */
927 	34,	/* 16G */
928 	20,	/* 1M, unsupported */
929 };
930 
931 static struct mmio_hpte_cache_entry *mmio_cache_search(struct kvm_vcpu *vcpu,
932 		unsigned long eaddr, unsigned long slb_v, long mmio_update)
933 {
934 	struct mmio_hpte_cache_entry *entry = NULL;
935 	unsigned int pshift;
936 	unsigned int i;
937 
938 	for (i = 0; i < MMIO_HPTE_CACHE_SIZE; i++) {
939 		entry = &vcpu->arch.mmio_cache.entry[i];
940 		if (entry->mmio_update == mmio_update) {
941 			pshift = entry->slb_base_pshift;
942 			if ((entry->eaddr >> pshift) == (eaddr >> pshift) &&
943 			    entry->slb_v == slb_v)
944 				return entry;
945 		}
946 	}
947 	return NULL;
948 }
949 
950 static struct mmio_hpte_cache_entry *
951 			next_mmio_cache_entry(struct kvm_vcpu *vcpu)
952 {
953 	unsigned int index = vcpu->arch.mmio_cache.index;
954 
955 	vcpu->arch.mmio_cache.index++;
956 	if (vcpu->arch.mmio_cache.index == MMIO_HPTE_CACHE_SIZE)
957 		vcpu->arch.mmio_cache.index = 0;
958 
959 	return &vcpu->arch.mmio_cache.entry[index];
960 }
961 
962 /* When called from virtmode, this func should be protected by
963  * preempt_disable(), otherwise, the holding of HPTE_V_HVLOCK
964  * can trigger deadlock issue.
965  */
966 long kvmppc_hv_find_lock_hpte(struct kvm *kvm, gva_t eaddr, unsigned long slb_v,
967 			      unsigned long valid)
968 {
969 	unsigned int i;
970 	unsigned int pshift;
971 	unsigned long somask;
972 	unsigned long vsid, hash;
973 	unsigned long avpn;
974 	__be64 *hpte;
975 	unsigned long mask, val;
976 	unsigned long v, r, orig_v;
977 
978 	/* Get page shift, work out hash and AVPN etc. */
979 	mask = SLB_VSID_B | HPTE_V_AVPN | HPTE_V_SECONDARY;
980 	val = 0;
981 	pshift = 12;
982 	if (slb_v & SLB_VSID_L) {
983 		mask |= HPTE_V_LARGE;
984 		val |= HPTE_V_LARGE;
985 		pshift = slb_base_page_shift[(slb_v & SLB_VSID_LP) >> 4];
986 	}
987 	if (slb_v & SLB_VSID_B_1T) {
988 		somask = (1UL << 40) - 1;
989 		vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT_1T;
990 		vsid ^= vsid << 25;
991 	} else {
992 		somask = (1UL << 28) - 1;
993 		vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT;
994 	}
995 	hash = (vsid ^ ((eaddr & somask) >> pshift)) & kvmppc_hpt_mask(&kvm->arch.hpt);
996 	avpn = slb_v & ~(somask >> 16);	/* also includes B */
997 	avpn |= (eaddr & somask) >> 16;
998 
999 	if (pshift >= 24)
1000 		avpn &= ~((1UL << (pshift - 16)) - 1);
1001 	else
1002 		avpn &= ~0x7fUL;
1003 	val |= avpn;
1004 
1005 	for (;;) {
1006 		hpte = (__be64 *)(kvm->arch.hpt.virt + (hash << 7));
1007 
1008 		for (i = 0; i < 16; i += 2) {
1009 			/* Read the PTE racily */
1010 			v = be64_to_cpu(hpte[i]) & ~HPTE_V_HVLOCK;
1011 			if (cpu_has_feature(CPU_FTR_ARCH_300))
1012 				v = hpte_new_to_old_v(v, be64_to_cpu(hpte[i+1]));
1013 
1014 			/* Check valid/absent, hash, segment size and AVPN */
1015 			if (!(v & valid) || (v & mask) != val)
1016 				continue;
1017 
1018 			/* Lock the PTE and read it under the lock */
1019 			while (!try_lock_hpte(&hpte[i], HPTE_V_HVLOCK))
1020 				cpu_relax();
1021 			v = orig_v = be64_to_cpu(hpte[i]) & ~HPTE_V_HVLOCK;
1022 			r = be64_to_cpu(hpte[i+1]);
1023 			if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1024 				v = hpte_new_to_old_v(v, r);
1025 				r = hpte_new_to_old_r(r);
1026 			}
1027 
1028 			/*
1029 			 * Check the HPTE again, including base page size
1030 			 */
1031 			if ((v & valid) && (v & mask) == val &&
1032 			    kvmppc_hpte_base_page_shift(v, r) == pshift)
1033 				/* Return with the HPTE still locked */
1034 				return (hash << 3) + (i >> 1);
1035 
1036 			__unlock_hpte(&hpte[i], orig_v);
1037 		}
1038 
1039 		if (val & HPTE_V_SECONDARY)
1040 			break;
1041 		val |= HPTE_V_SECONDARY;
1042 		hash = hash ^ kvmppc_hpt_mask(&kvm->arch.hpt);
1043 	}
1044 	return -1;
1045 }
1046 EXPORT_SYMBOL(kvmppc_hv_find_lock_hpte);
1047 
1048 /*
1049  * Called in real mode to check whether an HPTE not found fault
1050  * is due to accessing a paged-out page or an emulated MMIO page,
1051  * or if a protection fault is due to accessing a page that the
1052  * guest wanted read/write access to but which we made read-only.
1053  * Returns a possibly modified status (DSISR) value if not
1054  * (i.e. pass the interrupt to the guest),
1055  * -1 to pass the fault up to host kernel mode code, -2 to do that
1056  * and also load the instruction word (for MMIO emulation),
1057  * or 0 if we should make the guest retry the access.
1058  */
1059 long kvmppc_hpte_hv_fault(struct kvm_vcpu *vcpu, unsigned long addr,
1060 			  unsigned long slb_v, unsigned int status, bool data)
1061 {
1062 	struct kvm *kvm = vcpu->kvm;
1063 	long int index;
1064 	unsigned long v, r, gr, orig_v;
1065 	__be64 *hpte;
1066 	unsigned long valid;
1067 	struct revmap_entry *rev;
1068 	unsigned long pp, key;
1069 	struct mmio_hpte_cache_entry *cache_entry = NULL;
1070 	long mmio_update = 0;
1071 
1072 	/* For protection fault, expect to find a valid HPTE */
1073 	valid = HPTE_V_VALID;
1074 	if (status & DSISR_NOHPTE) {
1075 		valid |= HPTE_V_ABSENT;
1076 		mmio_update = atomic64_read(&kvm->arch.mmio_update);
1077 		cache_entry = mmio_cache_search(vcpu, addr, slb_v, mmio_update);
1078 	}
1079 	if (cache_entry) {
1080 		index = cache_entry->pte_index;
1081 		v = cache_entry->hpte_v;
1082 		r = cache_entry->hpte_r;
1083 		gr = cache_entry->rpte;
1084 	} else {
1085 		index = kvmppc_hv_find_lock_hpte(kvm, addr, slb_v, valid);
1086 		if (index < 0) {
1087 			if (status & DSISR_NOHPTE)
1088 				return status;	/* there really was no HPTE */
1089 			return 0;	/* for prot fault, HPTE disappeared */
1090 		}
1091 		hpte = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
1092 		v = orig_v = be64_to_cpu(hpte[0]) & ~HPTE_V_HVLOCK;
1093 		r = be64_to_cpu(hpte[1]);
1094 		if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1095 			v = hpte_new_to_old_v(v, r);
1096 			r = hpte_new_to_old_r(r);
1097 		}
1098 		rev = real_vmalloc_addr(&kvm->arch.hpt.rev[index]);
1099 		gr = rev->guest_rpte;
1100 
1101 		unlock_hpte(hpte, orig_v);
1102 	}
1103 
1104 	/* For not found, if the HPTE is valid by now, retry the instruction */
1105 	if ((status & DSISR_NOHPTE) && (v & HPTE_V_VALID))
1106 		return 0;
1107 
1108 	/* Check access permissions to the page */
1109 	pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
1110 	key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
1111 	status &= ~DSISR_NOHPTE;	/* DSISR_NOHPTE == SRR1_ISI_NOPT */
1112 	if (!data) {
1113 		if (gr & (HPTE_R_N | HPTE_R_G))
1114 			return status | SRR1_ISI_N_OR_G;
1115 		if (!hpte_read_permission(pp, slb_v & key))
1116 			return status | SRR1_ISI_PROT;
1117 	} else if (status & DSISR_ISSTORE) {
1118 		/* check write permission */
1119 		if (!hpte_write_permission(pp, slb_v & key))
1120 			return status | DSISR_PROTFAULT;
1121 	} else {
1122 		if (!hpte_read_permission(pp, slb_v & key))
1123 			return status | DSISR_PROTFAULT;
1124 	}
1125 
1126 	/* Check storage key, if applicable */
1127 	if (data && (vcpu->arch.shregs.msr & MSR_DR)) {
1128 		unsigned int perm = hpte_get_skey_perm(gr, vcpu->arch.amr);
1129 		if (status & DSISR_ISSTORE)
1130 			perm >>= 1;
1131 		if (perm & 1)
1132 			return status | DSISR_KEYFAULT;
1133 	}
1134 
1135 	/* Save HPTE info for virtual-mode handler */
1136 	vcpu->arch.pgfault_addr = addr;
1137 	vcpu->arch.pgfault_index = index;
1138 	vcpu->arch.pgfault_hpte[0] = v;
1139 	vcpu->arch.pgfault_hpte[1] = r;
1140 	vcpu->arch.pgfault_cache = cache_entry;
1141 
1142 	/* Check the storage key to see if it is possibly emulated MMIO */
1143 	if ((r & (HPTE_R_KEY_HI | HPTE_R_KEY_LO)) ==
1144 	    (HPTE_R_KEY_HI | HPTE_R_KEY_LO)) {
1145 		if (!cache_entry) {
1146 			unsigned int pshift = 12;
1147 			unsigned int pshift_index;
1148 
1149 			if (slb_v & SLB_VSID_L) {
1150 				pshift_index = ((slb_v & SLB_VSID_LP) >> 4);
1151 				pshift = slb_base_page_shift[pshift_index];
1152 			}
1153 			cache_entry = next_mmio_cache_entry(vcpu);
1154 			cache_entry->eaddr = addr;
1155 			cache_entry->slb_base_pshift = pshift;
1156 			cache_entry->pte_index = index;
1157 			cache_entry->hpte_v = v;
1158 			cache_entry->hpte_r = r;
1159 			cache_entry->rpte = gr;
1160 			cache_entry->slb_v = slb_v;
1161 			cache_entry->mmio_update = mmio_update;
1162 		}
1163 		if (data && (vcpu->arch.shregs.msr & MSR_IR))
1164 			return -2;	/* MMIO emulation - load instr word */
1165 	}
1166 
1167 	return -1;		/* send fault up to host kernel mode */
1168 }
1169