1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Copyright 2010-2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
5  */
6 
7 #include <linux/types.h>
8 #include <linux/string.h>
9 #include <linux/kvm.h>
10 #include <linux/kvm_host.h>
11 #include <linux/hugetlb.h>
12 #include <linux/module.h>
13 #include <linux/log2.h>
14 #include <linux/sizes.h>
15 
16 #include <asm/trace.h>
17 #include <asm/kvm_ppc.h>
18 #include <asm/kvm_book3s.h>
19 #include <asm/book3s/64/mmu-hash.h>
20 #include <asm/hvcall.h>
21 #include <asm/synch.h>
22 #include <asm/ppc-opcode.h>
23 #include <asm/pte-walk.h>
24 
25 /* Translate address of a vmalloc'd thing to a linear map address */
26 static void *real_vmalloc_addr(void *x)
27 {
28 	unsigned long addr = (unsigned long) x;
29 	pte_t *p;
30 	/*
31 	 * assume we don't have huge pages in vmalloc space...
32 	 * So don't worry about THP collapse/split. Called
33 	 * Only in realmode with MSR_EE = 0, hence won't need irq_save/restore.
34 	 */
35 	p = find_init_mm_pte(addr, NULL);
36 	if (!p || !pte_present(*p))
37 		return NULL;
38 	addr = (pte_pfn(*p) << PAGE_SHIFT) | (addr & ~PAGE_MASK);
39 	return __va(addr);
40 }
41 
42 /* Return 1 if we need to do a global tlbie, 0 if we can use tlbiel */
43 static int global_invalidates(struct kvm *kvm)
44 {
45 	int global;
46 	int cpu;
47 
48 	/*
49 	 * If there is only one vcore, and it's currently running,
50 	 * as indicated by local_paca->kvm_hstate.kvm_vcpu being set,
51 	 * we can use tlbiel as long as we mark all other physical
52 	 * cores as potentially having stale TLB entries for this lpid.
53 	 * Otherwise, don't use tlbiel.
54 	 */
55 	if (kvm->arch.online_vcores == 1 && local_paca->kvm_hstate.kvm_vcpu)
56 		global = 0;
57 	else
58 		global = 1;
59 
60 	if (!global) {
61 		/* any other core might now have stale TLB entries... */
62 		smp_wmb();
63 		cpumask_setall(&kvm->arch.need_tlb_flush);
64 		cpu = local_paca->kvm_hstate.kvm_vcore->pcpu;
65 		/*
66 		 * On POWER9, threads are independent but the TLB is shared,
67 		 * so use the bit for the first thread to represent the core.
68 		 */
69 		if (cpu_has_feature(CPU_FTR_ARCH_300))
70 			cpu = cpu_first_thread_sibling(cpu);
71 		cpumask_clear_cpu(cpu, &kvm->arch.need_tlb_flush);
72 	}
73 
74 	return global;
75 }
76 
77 /*
78  * Add this HPTE into the chain for the real page.
79  * Must be called with the chain locked; it unlocks the chain.
80  */
81 void kvmppc_add_revmap_chain(struct kvm *kvm, struct revmap_entry *rev,
82 			     unsigned long *rmap, long pte_index, int realmode)
83 {
84 	struct revmap_entry *head, *tail;
85 	unsigned long i;
86 
87 	if (*rmap & KVMPPC_RMAP_PRESENT) {
88 		i = *rmap & KVMPPC_RMAP_INDEX;
89 		head = &kvm->arch.hpt.rev[i];
90 		if (realmode)
91 			head = real_vmalloc_addr(head);
92 		tail = &kvm->arch.hpt.rev[head->back];
93 		if (realmode)
94 			tail = real_vmalloc_addr(tail);
95 		rev->forw = i;
96 		rev->back = head->back;
97 		tail->forw = pte_index;
98 		head->back = pte_index;
99 	} else {
100 		rev->forw = rev->back = pte_index;
101 		*rmap = (*rmap & ~KVMPPC_RMAP_INDEX) |
102 			pte_index | KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_HPT;
103 	}
104 	unlock_rmap(rmap);
105 }
106 EXPORT_SYMBOL_GPL(kvmppc_add_revmap_chain);
107 
108 /* Update the dirty bitmap of a memslot */
109 void kvmppc_update_dirty_map(const struct kvm_memory_slot *memslot,
110 			     unsigned long gfn, unsigned long psize)
111 {
112 	unsigned long npages;
113 
114 	if (!psize || !memslot->dirty_bitmap)
115 		return;
116 	npages = (psize + PAGE_SIZE - 1) / PAGE_SIZE;
117 	gfn -= memslot->base_gfn;
118 	set_dirty_bits_atomic(memslot->dirty_bitmap, gfn, npages);
119 }
120 EXPORT_SYMBOL_GPL(kvmppc_update_dirty_map);
121 
122 static void kvmppc_set_dirty_from_hpte(struct kvm *kvm,
123 				unsigned long hpte_v, unsigned long hpte_gr)
124 {
125 	struct kvm_memory_slot *memslot;
126 	unsigned long gfn;
127 	unsigned long psize;
128 
129 	psize = kvmppc_actual_pgsz(hpte_v, hpte_gr);
130 	gfn = hpte_rpn(hpte_gr, psize);
131 	memslot = __gfn_to_memslot(kvm_memslots_raw(kvm), gfn);
132 	if (memslot && memslot->dirty_bitmap)
133 		kvmppc_update_dirty_map(memslot, gfn, psize);
134 }
135 
136 /* Returns a pointer to the revmap entry for the page mapped by a HPTE */
137 static unsigned long *revmap_for_hpte(struct kvm *kvm, unsigned long hpte_v,
138 				      unsigned long hpte_gr,
139 				      struct kvm_memory_slot **memslotp,
140 				      unsigned long *gfnp)
141 {
142 	struct kvm_memory_slot *memslot;
143 	unsigned long *rmap;
144 	unsigned long gfn;
145 
146 	gfn = hpte_rpn(hpte_gr, kvmppc_actual_pgsz(hpte_v, hpte_gr));
147 	memslot = __gfn_to_memslot(kvm_memslots_raw(kvm), gfn);
148 	if (memslotp)
149 		*memslotp = memslot;
150 	if (gfnp)
151 		*gfnp = gfn;
152 	if (!memslot)
153 		return NULL;
154 
155 	rmap = real_vmalloc_addr(&memslot->arch.rmap[gfn - memslot->base_gfn]);
156 	return rmap;
157 }
158 
159 /* Remove this HPTE from the chain for a real page */
160 static void remove_revmap_chain(struct kvm *kvm, long pte_index,
161 				struct revmap_entry *rev,
162 				unsigned long hpte_v, unsigned long hpte_r)
163 {
164 	struct revmap_entry *next, *prev;
165 	unsigned long ptel, head;
166 	unsigned long *rmap;
167 	unsigned long rcbits;
168 	struct kvm_memory_slot *memslot;
169 	unsigned long gfn;
170 
171 	rcbits = hpte_r & (HPTE_R_R | HPTE_R_C);
172 	ptel = rev->guest_rpte |= rcbits;
173 	rmap = revmap_for_hpte(kvm, hpte_v, ptel, &memslot, &gfn);
174 	if (!rmap)
175 		return;
176 	lock_rmap(rmap);
177 
178 	head = *rmap & KVMPPC_RMAP_INDEX;
179 	next = real_vmalloc_addr(&kvm->arch.hpt.rev[rev->forw]);
180 	prev = real_vmalloc_addr(&kvm->arch.hpt.rev[rev->back]);
181 	next->back = rev->back;
182 	prev->forw = rev->forw;
183 	if (head == pte_index) {
184 		head = rev->forw;
185 		if (head == pte_index)
186 			*rmap &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
187 		else
188 			*rmap = (*rmap & ~KVMPPC_RMAP_INDEX) | head;
189 	}
190 	*rmap |= rcbits << KVMPPC_RMAP_RC_SHIFT;
191 	if (rcbits & HPTE_R_C)
192 		kvmppc_update_dirty_map(memslot, gfn,
193 					kvmppc_actual_pgsz(hpte_v, hpte_r));
194 	unlock_rmap(rmap);
195 }
196 
197 long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
198 		       long pte_index, unsigned long pteh, unsigned long ptel,
199 		       pgd_t *pgdir, bool realmode, unsigned long *pte_idx_ret)
200 {
201 	unsigned long i, pa, gpa, gfn, psize;
202 	unsigned long slot_fn, hva;
203 	__be64 *hpte;
204 	struct revmap_entry *rev;
205 	unsigned long g_ptel;
206 	struct kvm_memory_slot *memslot;
207 	unsigned hpage_shift;
208 	bool is_ci;
209 	unsigned long *rmap;
210 	pte_t *ptep;
211 	unsigned int writing;
212 	unsigned long mmu_seq;
213 	unsigned long rcbits;
214 
215 	if (kvm_is_radix(kvm))
216 		return H_FUNCTION;
217 	psize = kvmppc_actual_pgsz(pteh, ptel);
218 	if (!psize)
219 		return H_PARAMETER;
220 	writing = hpte_is_writable(ptel);
221 	pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID);
222 	ptel &= ~HPTE_GR_RESERVED;
223 	g_ptel = ptel;
224 
225 	/* used later to detect if we might have been invalidated */
226 	mmu_seq = kvm->mmu_notifier_seq;
227 	smp_rmb();
228 
229 	/* Find the memslot (if any) for this address */
230 	gpa = (ptel & HPTE_R_RPN) & ~(psize - 1);
231 	gfn = gpa >> PAGE_SHIFT;
232 	memslot = __gfn_to_memslot(kvm_memslots_raw(kvm), gfn);
233 	pa = 0;
234 	is_ci = false;
235 	rmap = NULL;
236 	if (!(memslot && !(memslot->flags & KVM_MEMSLOT_INVALID))) {
237 		/* Emulated MMIO - mark this with key=31 */
238 		pteh |= HPTE_V_ABSENT;
239 		ptel |= HPTE_R_KEY_HI | HPTE_R_KEY_LO;
240 		goto do_insert;
241 	}
242 
243 	/* Check if the requested page fits entirely in the memslot. */
244 	if (!slot_is_aligned(memslot, psize))
245 		return H_PARAMETER;
246 	slot_fn = gfn - memslot->base_gfn;
247 	rmap = &memslot->arch.rmap[slot_fn];
248 
249 	/* Translate to host virtual address */
250 	hva = __gfn_to_hva_memslot(memslot, gfn);
251 
252 	arch_spin_lock(&kvm->mmu_lock.rlock.raw_lock);
253 	ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &hpage_shift);
254 	if (ptep) {
255 		pte_t pte;
256 		unsigned int host_pte_size;
257 
258 		if (hpage_shift)
259 			host_pte_size = 1ul << hpage_shift;
260 		else
261 			host_pte_size = PAGE_SIZE;
262 		/*
263 		 * We should always find the guest page size
264 		 * to <= host page size, if host is using hugepage
265 		 */
266 		if (host_pte_size < psize) {
267 			arch_spin_unlock(&kvm->mmu_lock.rlock.raw_lock);
268 			return H_PARAMETER;
269 		}
270 		pte = kvmppc_read_update_linux_pte(ptep, writing);
271 		if (pte_present(pte) && !pte_protnone(pte)) {
272 			if (writing && !__pte_write(pte))
273 				/* make the actual HPTE be read-only */
274 				ptel = hpte_make_readonly(ptel);
275 			is_ci = pte_ci(pte);
276 			pa = pte_pfn(pte) << PAGE_SHIFT;
277 			pa |= hva & (host_pte_size - 1);
278 			pa |= gpa & ~PAGE_MASK;
279 		}
280 	}
281 	arch_spin_unlock(&kvm->mmu_lock.rlock.raw_lock);
282 
283 	ptel &= HPTE_R_KEY | HPTE_R_PP0 | (psize-1);
284 	ptel |= pa;
285 
286 	if (pa)
287 		pteh |= HPTE_V_VALID;
288 	else {
289 		pteh |= HPTE_V_ABSENT;
290 		ptel &= ~(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
291 	}
292 
293 	/*If we had host pte mapping then  Check WIMG */
294 	if (ptep && !hpte_cache_flags_ok(ptel, is_ci)) {
295 		if (is_ci)
296 			return H_PARAMETER;
297 		/*
298 		 * Allow guest to map emulated device memory as
299 		 * uncacheable, but actually make it cacheable.
300 		 */
301 		ptel &= ~(HPTE_R_W|HPTE_R_I|HPTE_R_G);
302 		ptel |= HPTE_R_M;
303 	}
304 
305 	/* Find and lock the HPTEG slot to use */
306  do_insert:
307 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
308 		return H_PARAMETER;
309 	if (likely((flags & H_EXACT) == 0)) {
310 		pte_index &= ~7UL;
311 		hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
312 		for (i = 0; i < 8; ++i) {
313 			if ((be64_to_cpu(*hpte) & HPTE_V_VALID) == 0 &&
314 			    try_lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID |
315 					  HPTE_V_ABSENT))
316 				break;
317 			hpte += 2;
318 		}
319 		if (i == 8) {
320 			/*
321 			 * Since try_lock_hpte doesn't retry (not even stdcx.
322 			 * failures), it could be that there is a free slot
323 			 * but we transiently failed to lock it.  Try again,
324 			 * actually locking each slot and checking it.
325 			 */
326 			hpte -= 16;
327 			for (i = 0; i < 8; ++i) {
328 				u64 pte;
329 				while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
330 					cpu_relax();
331 				pte = be64_to_cpu(hpte[0]);
332 				if (!(pte & (HPTE_V_VALID | HPTE_V_ABSENT)))
333 					break;
334 				__unlock_hpte(hpte, pte);
335 				hpte += 2;
336 			}
337 			if (i == 8)
338 				return H_PTEG_FULL;
339 		}
340 		pte_index += i;
341 	} else {
342 		hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
343 		if (!try_lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID |
344 				   HPTE_V_ABSENT)) {
345 			/* Lock the slot and check again */
346 			u64 pte;
347 
348 			while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
349 				cpu_relax();
350 			pte = be64_to_cpu(hpte[0]);
351 			if (pte & (HPTE_V_VALID | HPTE_V_ABSENT)) {
352 				__unlock_hpte(hpte, pte);
353 				return H_PTEG_FULL;
354 			}
355 		}
356 	}
357 
358 	/* Save away the guest's idea of the second HPTE dword */
359 	rev = &kvm->arch.hpt.rev[pte_index];
360 	if (realmode)
361 		rev = real_vmalloc_addr(rev);
362 	if (rev) {
363 		rev->guest_rpte = g_ptel;
364 		note_hpte_modification(kvm, rev);
365 	}
366 
367 	/* Link HPTE into reverse-map chain */
368 	if (pteh & HPTE_V_VALID) {
369 		if (realmode)
370 			rmap = real_vmalloc_addr(rmap);
371 		lock_rmap(rmap);
372 		/* Check for pending invalidations under the rmap chain lock */
373 		if (mmu_notifier_retry(kvm, mmu_seq)) {
374 			/* inval in progress, write a non-present HPTE */
375 			pteh |= HPTE_V_ABSENT;
376 			pteh &= ~HPTE_V_VALID;
377 			ptel &= ~(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
378 			unlock_rmap(rmap);
379 		} else {
380 			kvmppc_add_revmap_chain(kvm, rev, rmap, pte_index,
381 						realmode);
382 			/* Only set R/C in real HPTE if already set in *rmap */
383 			rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
384 			ptel &= rcbits | ~(HPTE_R_R | HPTE_R_C);
385 		}
386 	}
387 
388 	/* Convert to new format on P9 */
389 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
390 		ptel = hpte_old_to_new_r(pteh, ptel);
391 		pteh = hpte_old_to_new_v(pteh);
392 	}
393 	hpte[1] = cpu_to_be64(ptel);
394 
395 	/* Write the first HPTE dword, unlocking the HPTE and making it valid */
396 	eieio();
397 	__unlock_hpte(hpte, pteh);
398 	asm volatile("ptesync" : : : "memory");
399 
400 	*pte_idx_ret = pte_index;
401 	return H_SUCCESS;
402 }
403 EXPORT_SYMBOL_GPL(kvmppc_do_h_enter);
404 
405 long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
406 		    long pte_index, unsigned long pteh, unsigned long ptel)
407 {
408 	return kvmppc_do_h_enter(vcpu->kvm, flags, pte_index, pteh, ptel,
409 				 vcpu->arch.pgdir, true,
410 				 &vcpu->arch.regs.gpr[4]);
411 }
412 
413 #ifdef __BIG_ENDIAN__
414 #define LOCK_TOKEN	(*(u32 *)(&get_paca()->lock_token))
415 #else
416 #define LOCK_TOKEN	(*(u32 *)(&get_paca()->paca_index))
417 #endif
418 
419 static inline int is_mmio_hpte(unsigned long v, unsigned long r)
420 {
421 	return ((v & HPTE_V_ABSENT) &&
422 		(r & (HPTE_R_KEY_HI | HPTE_R_KEY_LO)) ==
423 		(HPTE_R_KEY_HI | HPTE_R_KEY_LO));
424 }
425 
426 static inline void fixup_tlbie_lpid(unsigned long rb_value, unsigned long lpid)
427 {
428 
429 	if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
430 		/* Radix flush for a hash guest */
431 
432 		unsigned long rb,rs,prs,r,ric;
433 
434 		rb = PPC_BIT(52); /* IS = 2 */
435 		rs = 0;  /* lpid = 0 */
436 		prs = 0; /* partition scoped */
437 		r = 1;   /* radix format */
438 		ric = 0; /* RIC_FLSUH_TLB */
439 
440 		/*
441 		 * Need the extra ptesync to make sure we don't
442 		 * re-order the tlbie
443 		 */
444 		asm volatile("ptesync": : :"memory");
445 		asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
446 			     : : "r"(rb), "i"(r), "i"(prs),
447 			       "i"(ric), "r"(rs) : "memory");
448 	}
449 
450 	if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
451 		asm volatile("ptesync": : :"memory");
452 		asm volatile(PPC_TLBIE_5(%0,%1,0,0,0) : :
453 			     "r" (rb_value), "r" (lpid));
454 	}
455 }
456 
457 static void do_tlbies(struct kvm *kvm, unsigned long *rbvalues,
458 		      long npages, int global, bool need_sync)
459 {
460 	long i;
461 
462 	/*
463 	 * We use the POWER9 5-operand versions of tlbie and tlbiel here.
464 	 * Since we are using RIC=0 PRS=0 R=0, and P7/P8 tlbiel ignores
465 	 * the RS field, this is backwards-compatible with P7 and P8.
466 	 */
467 	if (global) {
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 		}
474 
475 		fixup_tlbie_lpid(rbvalues[i - 1], kvm->arch.lpid);
476 		asm volatile("eieio; tlbsync; ptesync" : : : "memory");
477 	} else {
478 		if (need_sync)
479 			asm volatile("ptesync" : : : "memory");
480 		for (i = 0; i < npages; ++i) {
481 			asm volatile(PPC_TLBIEL(%0,%1,0,0,0) : :
482 				     "r" (rbvalues[i]), "r" (0));
483 		}
484 		asm volatile("ptesync" : : : "memory");
485 	}
486 }
487 
488 long kvmppc_do_h_remove(struct kvm *kvm, unsigned long flags,
489 			unsigned long pte_index, unsigned long avpn,
490 			unsigned long *hpret)
491 {
492 	__be64 *hpte;
493 	unsigned long v, r, rb;
494 	struct revmap_entry *rev;
495 	u64 pte, orig_pte, pte_r;
496 
497 	if (kvm_is_radix(kvm))
498 		return H_FUNCTION;
499 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
500 		return H_PARAMETER;
501 	hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
502 	while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
503 		cpu_relax();
504 	pte = orig_pte = be64_to_cpu(hpte[0]);
505 	pte_r = be64_to_cpu(hpte[1]);
506 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
507 		pte = hpte_new_to_old_v(pte, pte_r);
508 		pte_r = hpte_new_to_old_r(pte_r);
509 	}
510 	if ((pte & (HPTE_V_ABSENT | HPTE_V_VALID)) == 0 ||
511 	    ((flags & H_AVPN) && (pte & ~0x7fUL) != avpn) ||
512 	    ((flags & H_ANDCOND) && (pte & avpn) != 0)) {
513 		__unlock_hpte(hpte, orig_pte);
514 		return H_NOT_FOUND;
515 	}
516 
517 	rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
518 	v = pte & ~HPTE_V_HVLOCK;
519 	if (v & HPTE_V_VALID) {
520 		hpte[0] &= ~cpu_to_be64(HPTE_V_VALID);
521 		rb = compute_tlbie_rb(v, pte_r, pte_index);
522 		do_tlbies(kvm, &rb, 1, global_invalidates(kvm), true);
523 		/*
524 		 * The reference (R) and change (C) bits in a HPT
525 		 * entry can be set by hardware at any time up until
526 		 * the HPTE is invalidated and the TLB invalidation
527 		 * sequence has completed.  This means that when
528 		 * removing a HPTE, we need to re-read the HPTE after
529 		 * the invalidation sequence has completed in order to
530 		 * obtain reliable values of R and C.
531 		 */
532 		remove_revmap_chain(kvm, pte_index, rev, v,
533 				    be64_to_cpu(hpte[1]));
534 	}
535 	r = rev->guest_rpte & ~HPTE_GR_RESERVED;
536 	note_hpte_modification(kvm, rev);
537 	unlock_hpte(hpte, 0);
538 
539 	if (is_mmio_hpte(v, pte_r))
540 		atomic64_inc(&kvm->arch.mmio_update);
541 
542 	if (v & HPTE_V_ABSENT)
543 		v = (v & ~HPTE_V_ABSENT) | HPTE_V_VALID;
544 	hpret[0] = v;
545 	hpret[1] = r;
546 	return H_SUCCESS;
547 }
548 EXPORT_SYMBOL_GPL(kvmppc_do_h_remove);
549 
550 long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
551 		     unsigned long pte_index, unsigned long avpn)
552 {
553 	return kvmppc_do_h_remove(vcpu->kvm, flags, pte_index, avpn,
554 				  &vcpu->arch.regs.gpr[4]);
555 }
556 
557 long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
558 {
559 	struct kvm *kvm = vcpu->kvm;
560 	unsigned long *args = &vcpu->arch.regs.gpr[4];
561 	__be64 *hp, *hptes[4];
562 	unsigned long tlbrb[4];
563 	long int i, j, k, n, found, indexes[4];
564 	unsigned long flags, req, pte_index, rcbits;
565 	int global;
566 	long int ret = H_SUCCESS;
567 	struct revmap_entry *rev, *revs[4];
568 	u64 hp0, hp1;
569 
570 	if (kvm_is_radix(kvm))
571 		return H_FUNCTION;
572 	global = global_invalidates(kvm);
573 	for (i = 0; i < 4 && ret == H_SUCCESS; ) {
574 		n = 0;
575 		for (; i < 4; ++i) {
576 			j = i * 2;
577 			pte_index = args[j];
578 			flags = pte_index >> 56;
579 			pte_index &= ((1ul << 56) - 1);
580 			req = flags >> 6;
581 			flags &= 3;
582 			if (req == 3) {		/* no more requests */
583 				i = 4;
584 				break;
585 			}
586 			if (req != 1 || flags == 3 ||
587 			    pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt)) {
588 				/* parameter error */
589 				args[j] = ((0xa0 | flags) << 56) + pte_index;
590 				ret = H_PARAMETER;
591 				break;
592 			}
593 			hp = (__be64 *) (kvm->arch.hpt.virt + (pte_index << 4));
594 			/* to avoid deadlock, don't spin except for first */
595 			if (!try_lock_hpte(hp, HPTE_V_HVLOCK)) {
596 				if (n)
597 					break;
598 				while (!try_lock_hpte(hp, HPTE_V_HVLOCK))
599 					cpu_relax();
600 			}
601 			found = 0;
602 			hp0 = be64_to_cpu(hp[0]);
603 			hp1 = be64_to_cpu(hp[1]);
604 			if (cpu_has_feature(CPU_FTR_ARCH_300)) {
605 				hp0 = hpte_new_to_old_v(hp0, hp1);
606 				hp1 = hpte_new_to_old_r(hp1);
607 			}
608 			if (hp0 & (HPTE_V_ABSENT | HPTE_V_VALID)) {
609 				switch (flags & 3) {
610 				case 0:		/* absolute */
611 					found = 1;
612 					break;
613 				case 1:		/* andcond */
614 					if (!(hp0 & args[j + 1]))
615 						found = 1;
616 					break;
617 				case 2:		/* AVPN */
618 					if ((hp0 & ~0x7fUL) == args[j + 1])
619 						found = 1;
620 					break;
621 				}
622 			}
623 			if (!found) {
624 				hp[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
625 				args[j] = ((0x90 | flags) << 56) + pte_index;
626 				continue;
627 			}
628 
629 			args[j] = ((0x80 | flags) << 56) + pte_index;
630 			rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
631 			note_hpte_modification(kvm, rev);
632 
633 			if (!(hp0 & HPTE_V_VALID)) {
634 				/* insert R and C bits from PTE */
635 				rcbits = rev->guest_rpte & (HPTE_R_R|HPTE_R_C);
636 				args[j] |= rcbits << (56 - 5);
637 				hp[0] = 0;
638 				if (is_mmio_hpte(hp0, hp1))
639 					atomic64_inc(&kvm->arch.mmio_update);
640 				continue;
641 			}
642 
643 			/* leave it locked */
644 			hp[0] &= ~cpu_to_be64(HPTE_V_VALID);
645 			tlbrb[n] = compute_tlbie_rb(hp0, hp1, pte_index);
646 			indexes[n] = j;
647 			hptes[n] = hp;
648 			revs[n] = rev;
649 			++n;
650 		}
651 
652 		if (!n)
653 			break;
654 
655 		/* Now that we've collected a batch, do the tlbies */
656 		do_tlbies(kvm, tlbrb, n, global, true);
657 
658 		/* Read PTE low words after tlbie to get final R/C values */
659 		for (k = 0; k < n; ++k) {
660 			j = indexes[k];
661 			pte_index = args[j] & ((1ul << 56) - 1);
662 			hp = hptes[k];
663 			rev = revs[k];
664 			remove_revmap_chain(kvm, pte_index, rev,
665 				be64_to_cpu(hp[0]), be64_to_cpu(hp[1]));
666 			rcbits = rev->guest_rpte & (HPTE_R_R|HPTE_R_C);
667 			args[j] |= rcbits << (56 - 5);
668 			__unlock_hpte(hp, 0);
669 		}
670 	}
671 
672 	return ret;
673 }
674 
675 long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
676 		      unsigned long pte_index, unsigned long avpn,
677 		      unsigned long va)
678 {
679 	struct kvm *kvm = vcpu->kvm;
680 	__be64 *hpte;
681 	struct revmap_entry *rev;
682 	unsigned long v, r, rb, mask, bits;
683 	u64 pte_v, pte_r;
684 
685 	if (kvm_is_radix(kvm))
686 		return H_FUNCTION;
687 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
688 		return H_PARAMETER;
689 
690 	hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
691 	while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
692 		cpu_relax();
693 	v = pte_v = be64_to_cpu(hpte[0]);
694 	if (cpu_has_feature(CPU_FTR_ARCH_300))
695 		v = hpte_new_to_old_v(v, be64_to_cpu(hpte[1]));
696 	if ((v & (HPTE_V_ABSENT | HPTE_V_VALID)) == 0 ||
697 	    ((flags & H_AVPN) && (v & ~0x7fUL) != avpn)) {
698 		__unlock_hpte(hpte, pte_v);
699 		return H_NOT_FOUND;
700 	}
701 
702 	pte_r = be64_to_cpu(hpte[1]);
703 	bits = (flags << 55) & HPTE_R_PP0;
704 	bits |= (flags << 48) & HPTE_R_KEY_HI;
705 	bits |= flags & (HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_LO);
706 
707 	/* Update guest view of 2nd HPTE dword */
708 	mask = HPTE_R_PP0 | HPTE_R_PP | HPTE_R_N |
709 		HPTE_R_KEY_HI | HPTE_R_KEY_LO;
710 	rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
711 	if (rev) {
712 		r = (rev->guest_rpte & ~mask) | bits;
713 		rev->guest_rpte = r;
714 		note_hpte_modification(kvm, rev);
715 	}
716 
717 	/* Update HPTE */
718 	if (v & HPTE_V_VALID) {
719 		/*
720 		 * If the page is valid, don't let it transition from
721 		 * readonly to writable.  If it should be writable, we'll
722 		 * take a trap and let the page fault code sort it out.
723 		 */
724 		r = (pte_r & ~mask) | bits;
725 		if (hpte_is_writable(r) && !hpte_is_writable(pte_r))
726 			r = hpte_make_readonly(r);
727 		/* If the PTE is changing, invalidate it first */
728 		if (r != pte_r) {
729 			rb = compute_tlbie_rb(v, r, pte_index);
730 			hpte[0] = cpu_to_be64((pte_v & ~HPTE_V_VALID) |
731 					      HPTE_V_ABSENT);
732 			do_tlbies(kvm, &rb, 1, global_invalidates(kvm), true);
733 			/* Don't lose R/C bit updates done by hardware */
734 			r |= be64_to_cpu(hpte[1]) & (HPTE_R_R | HPTE_R_C);
735 			hpte[1] = cpu_to_be64(r);
736 		}
737 	}
738 	unlock_hpte(hpte, pte_v & ~HPTE_V_HVLOCK);
739 	asm volatile("ptesync" : : : "memory");
740 	if (is_mmio_hpte(v, pte_r))
741 		atomic64_inc(&kvm->arch.mmio_update);
742 
743 	return H_SUCCESS;
744 }
745 
746 long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
747 		   unsigned long pte_index)
748 {
749 	struct kvm *kvm = vcpu->kvm;
750 	__be64 *hpte;
751 	unsigned long v, r;
752 	int i, n = 1;
753 	struct revmap_entry *rev = NULL;
754 
755 	if (kvm_is_radix(kvm))
756 		return H_FUNCTION;
757 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
758 		return H_PARAMETER;
759 	if (flags & H_READ_4) {
760 		pte_index &= ~3;
761 		n = 4;
762 	}
763 	rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
764 	for (i = 0; i < n; ++i, ++pte_index) {
765 		hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
766 		v = be64_to_cpu(hpte[0]) & ~HPTE_V_HVLOCK;
767 		r = be64_to_cpu(hpte[1]);
768 		if (cpu_has_feature(CPU_FTR_ARCH_300)) {
769 			v = hpte_new_to_old_v(v, r);
770 			r = hpte_new_to_old_r(r);
771 		}
772 		if (v & HPTE_V_ABSENT) {
773 			v &= ~HPTE_V_ABSENT;
774 			v |= HPTE_V_VALID;
775 		}
776 		if (v & HPTE_V_VALID) {
777 			r = rev[i].guest_rpte | (r & (HPTE_R_R | HPTE_R_C));
778 			r &= ~HPTE_GR_RESERVED;
779 		}
780 		vcpu->arch.regs.gpr[4 + i * 2] = v;
781 		vcpu->arch.regs.gpr[5 + i * 2] = r;
782 	}
783 	return H_SUCCESS;
784 }
785 
786 long kvmppc_h_clear_ref(struct kvm_vcpu *vcpu, unsigned long flags,
787 			unsigned long pte_index)
788 {
789 	struct kvm *kvm = vcpu->kvm;
790 	__be64 *hpte;
791 	unsigned long v, r, gr;
792 	struct revmap_entry *rev;
793 	unsigned long *rmap;
794 	long ret = H_NOT_FOUND;
795 
796 	if (kvm_is_radix(kvm))
797 		return H_FUNCTION;
798 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
799 		return H_PARAMETER;
800 
801 	rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
802 	hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
803 	while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
804 		cpu_relax();
805 	v = be64_to_cpu(hpte[0]);
806 	r = be64_to_cpu(hpte[1]);
807 	if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
808 		goto out;
809 
810 	gr = rev->guest_rpte;
811 	if (rev->guest_rpte & HPTE_R_R) {
812 		rev->guest_rpte &= ~HPTE_R_R;
813 		note_hpte_modification(kvm, rev);
814 	}
815 	if (v & HPTE_V_VALID) {
816 		gr |= r & (HPTE_R_R | HPTE_R_C);
817 		if (r & HPTE_R_R) {
818 			kvmppc_clear_ref_hpte(kvm, hpte, pte_index);
819 			rmap = revmap_for_hpte(kvm, v, gr, NULL, NULL);
820 			if (rmap) {
821 				lock_rmap(rmap);
822 				*rmap |= KVMPPC_RMAP_REFERENCED;
823 				unlock_rmap(rmap);
824 			}
825 		}
826 	}
827 	vcpu->arch.regs.gpr[4] = gr;
828 	ret = H_SUCCESS;
829  out:
830 	unlock_hpte(hpte, v & ~HPTE_V_HVLOCK);
831 	return ret;
832 }
833 
834 long kvmppc_h_clear_mod(struct kvm_vcpu *vcpu, unsigned long flags,
835 			unsigned long pte_index)
836 {
837 	struct kvm *kvm = vcpu->kvm;
838 	__be64 *hpte;
839 	unsigned long v, r, gr;
840 	struct revmap_entry *rev;
841 	long ret = H_NOT_FOUND;
842 
843 	if (kvm_is_radix(kvm))
844 		return H_FUNCTION;
845 	if (pte_index >= kvmppc_hpt_npte(&kvm->arch.hpt))
846 		return H_PARAMETER;
847 
848 	rev = real_vmalloc_addr(&kvm->arch.hpt.rev[pte_index]);
849 	hpte = (__be64 *)(kvm->arch.hpt.virt + (pte_index << 4));
850 	while (!try_lock_hpte(hpte, HPTE_V_HVLOCK))
851 		cpu_relax();
852 	v = be64_to_cpu(hpte[0]);
853 	r = be64_to_cpu(hpte[1]);
854 	if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
855 		goto out;
856 
857 	gr = rev->guest_rpte;
858 	if (gr & HPTE_R_C) {
859 		rev->guest_rpte &= ~HPTE_R_C;
860 		note_hpte_modification(kvm, rev);
861 	}
862 	if (v & HPTE_V_VALID) {
863 		/* need to make it temporarily absent so C is stable */
864 		hpte[0] |= cpu_to_be64(HPTE_V_ABSENT);
865 		kvmppc_invalidate_hpte(kvm, hpte, pte_index);
866 		r = be64_to_cpu(hpte[1]);
867 		gr |= r & (HPTE_R_R | HPTE_R_C);
868 		if (r & HPTE_R_C) {
869 			hpte[1] = cpu_to_be64(r & ~HPTE_R_C);
870 			eieio();
871 			kvmppc_set_dirty_from_hpte(kvm, v, gr);
872 		}
873 	}
874 	vcpu->arch.regs.gpr[4] = gr;
875 	ret = H_SUCCESS;
876  out:
877 	unlock_hpte(hpte, v & ~HPTE_V_HVLOCK);
878 	return ret;
879 }
880 
881 static int kvmppc_get_hpa(struct kvm_vcpu *vcpu, unsigned long mmu_seq,
882 			  unsigned long gpa, int writing, unsigned long *hpa,
883 			  struct kvm_memory_slot **memslot_p)
884 {
885 	struct kvm *kvm = vcpu->kvm;
886 	struct kvm_memory_slot *memslot;
887 	unsigned long gfn, hva, pa, psize = PAGE_SHIFT;
888 	unsigned int shift;
889 	pte_t *ptep, pte;
890 
891 	/* Find the memslot for this address */
892 	gfn = gpa >> PAGE_SHIFT;
893 	memslot = __gfn_to_memslot(kvm_memslots_raw(kvm), gfn);
894 	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
895 		return H_PARAMETER;
896 
897 	/* Translate to host virtual address */
898 	hva = __gfn_to_hva_memslot(memslot, gfn);
899 
900 	/* Try to find the host pte for that virtual address */
901 	ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &shift);
902 	if (!ptep)
903 		return H_TOO_HARD;
904 	pte = kvmppc_read_update_linux_pte(ptep, writing);
905 	if (!pte_present(pte))
906 		return H_TOO_HARD;
907 
908 	/* Convert to a physical address */
909 	if (shift)
910 		psize = 1UL << shift;
911 	pa = pte_pfn(pte) << PAGE_SHIFT;
912 	pa |= hva & (psize - 1);
913 	pa |= gpa & ~PAGE_MASK;
914 
915 	if (hpa)
916 		*hpa = pa;
917 	if (memslot_p)
918 		*memslot_p = memslot;
919 
920 	return H_SUCCESS;
921 }
922 
923 static long kvmppc_do_h_page_init_zero(struct kvm_vcpu *vcpu,
924 				       unsigned long dest)
925 {
926 	struct kvm_memory_slot *memslot;
927 	struct kvm *kvm = vcpu->kvm;
928 	unsigned long pa, mmu_seq;
929 	long ret = H_SUCCESS;
930 	int i;
931 
932 	/* Used later to detect if we might have been invalidated */
933 	mmu_seq = kvm->mmu_notifier_seq;
934 	smp_rmb();
935 
936 	arch_spin_lock(&kvm->mmu_lock.rlock.raw_lock);
937 
938 	ret = kvmppc_get_hpa(vcpu, mmu_seq, dest, 1, &pa, &memslot);
939 	if (ret != H_SUCCESS)
940 		goto out_unlock;
941 
942 	/* Zero the page */
943 	for (i = 0; i < SZ_4K; i += L1_CACHE_BYTES, pa += L1_CACHE_BYTES)
944 		dcbz((void *)pa);
945 	kvmppc_update_dirty_map(memslot, dest >> PAGE_SHIFT, PAGE_SIZE);
946 
947 out_unlock:
948 	arch_spin_unlock(&kvm->mmu_lock.rlock.raw_lock);
949 	return ret;
950 }
951 
952 static long kvmppc_do_h_page_init_copy(struct kvm_vcpu *vcpu,
953 				       unsigned long dest, unsigned long src)
954 {
955 	unsigned long dest_pa, src_pa, mmu_seq;
956 	struct kvm_memory_slot *dest_memslot;
957 	struct kvm *kvm = vcpu->kvm;
958 	long ret = H_SUCCESS;
959 
960 	/* Used later to detect if we might have been invalidated */
961 	mmu_seq = kvm->mmu_notifier_seq;
962 	smp_rmb();
963 
964 	arch_spin_lock(&kvm->mmu_lock.rlock.raw_lock);
965 	ret = kvmppc_get_hpa(vcpu, mmu_seq, dest, 1, &dest_pa, &dest_memslot);
966 	if (ret != H_SUCCESS)
967 		goto out_unlock;
968 
969 	ret = kvmppc_get_hpa(vcpu, mmu_seq, src, 0, &src_pa, NULL);
970 	if (ret != H_SUCCESS)
971 		goto out_unlock;
972 
973 	/* Copy the page */
974 	memcpy((void *)dest_pa, (void *)src_pa, SZ_4K);
975 
976 	kvmppc_update_dirty_map(dest_memslot, dest >> PAGE_SHIFT, PAGE_SIZE);
977 
978 out_unlock:
979 	arch_spin_unlock(&kvm->mmu_lock.rlock.raw_lock);
980 	return ret;
981 }
982 
983 long kvmppc_rm_h_page_init(struct kvm_vcpu *vcpu, unsigned long flags,
984 			   unsigned long dest, unsigned long src)
985 {
986 	struct kvm *kvm = vcpu->kvm;
987 	u64 pg_mask = SZ_4K - 1;	/* 4K page size */
988 	long ret = H_SUCCESS;
989 
990 	/* Don't handle radix mode here, go up to the virtual mode handler */
991 	if (kvm_is_radix(kvm))
992 		return H_TOO_HARD;
993 
994 	/* Check for invalid flags (H_PAGE_SET_LOANED covers all CMO flags) */
995 	if (flags & ~(H_ICACHE_INVALIDATE | H_ICACHE_SYNCHRONIZE |
996 		      H_ZERO_PAGE | H_COPY_PAGE | H_PAGE_SET_LOANED))
997 		return H_PARAMETER;
998 
999 	/* dest (and src if copy_page flag set) must be page aligned */
1000 	if ((dest & pg_mask) || ((flags & H_COPY_PAGE) && (src & pg_mask)))
1001 		return H_PARAMETER;
1002 
1003 	/* zero and/or copy the page as determined by the flags */
1004 	if (flags & H_COPY_PAGE)
1005 		ret = kvmppc_do_h_page_init_copy(vcpu, dest, src);
1006 	else if (flags & H_ZERO_PAGE)
1007 		ret = kvmppc_do_h_page_init_zero(vcpu, dest);
1008 
1009 	/* We can ignore the other flags */
1010 
1011 	return ret;
1012 }
1013 
1014 void kvmppc_invalidate_hpte(struct kvm *kvm, __be64 *hptep,
1015 			unsigned long pte_index)
1016 {
1017 	unsigned long rb;
1018 	u64 hp0, hp1;
1019 
1020 	hptep[0] &= ~cpu_to_be64(HPTE_V_VALID);
1021 	hp0 = be64_to_cpu(hptep[0]);
1022 	hp1 = be64_to_cpu(hptep[1]);
1023 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1024 		hp0 = hpte_new_to_old_v(hp0, hp1);
1025 		hp1 = hpte_new_to_old_r(hp1);
1026 	}
1027 	rb = compute_tlbie_rb(hp0, hp1, pte_index);
1028 	do_tlbies(kvm, &rb, 1, 1, true);
1029 }
1030 EXPORT_SYMBOL_GPL(kvmppc_invalidate_hpte);
1031 
1032 void kvmppc_clear_ref_hpte(struct kvm *kvm, __be64 *hptep,
1033 			   unsigned long pte_index)
1034 {
1035 	unsigned long rb;
1036 	unsigned char rbyte;
1037 	u64 hp0, hp1;
1038 
1039 	hp0 = be64_to_cpu(hptep[0]);
1040 	hp1 = be64_to_cpu(hptep[1]);
1041 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1042 		hp0 = hpte_new_to_old_v(hp0, hp1);
1043 		hp1 = hpte_new_to_old_r(hp1);
1044 	}
1045 	rb = compute_tlbie_rb(hp0, hp1, pte_index);
1046 	rbyte = (be64_to_cpu(hptep[1]) & ~HPTE_R_R) >> 8;
1047 	/* modify only the second-last byte, which contains the ref bit */
1048 	*((char *)hptep + 14) = rbyte;
1049 	do_tlbies(kvm, &rb, 1, 1, false);
1050 }
1051 EXPORT_SYMBOL_GPL(kvmppc_clear_ref_hpte);
1052 
1053 static int slb_base_page_shift[4] = {
1054 	24,	/* 16M */
1055 	16,	/* 64k */
1056 	34,	/* 16G */
1057 	20,	/* 1M, unsupported */
1058 };
1059 
1060 static struct mmio_hpte_cache_entry *mmio_cache_search(struct kvm_vcpu *vcpu,
1061 		unsigned long eaddr, unsigned long slb_v, long mmio_update)
1062 {
1063 	struct mmio_hpte_cache_entry *entry = NULL;
1064 	unsigned int pshift;
1065 	unsigned int i;
1066 
1067 	for (i = 0; i < MMIO_HPTE_CACHE_SIZE; i++) {
1068 		entry = &vcpu->arch.mmio_cache.entry[i];
1069 		if (entry->mmio_update == mmio_update) {
1070 			pshift = entry->slb_base_pshift;
1071 			if ((entry->eaddr >> pshift) == (eaddr >> pshift) &&
1072 			    entry->slb_v == slb_v)
1073 				return entry;
1074 		}
1075 	}
1076 	return NULL;
1077 }
1078 
1079 static struct mmio_hpte_cache_entry *
1080 			next_mmio_cache_entry(struct kvm_vcpu *vcpu)
1081 {
1082 	unsigned int index = vcpu->arch.mmio_cache.index;
1083 
1084 	vcpu->arch.mmio_cache.index++;
1085 	if (vcpu->arch.mmio_cache.index == MMIO_HPTE_CACHE_SIZE)
1086 		vcpu->arch.mmio_cache.index = 0;
1087 
1088 	return &vcpu->arch.mmio_cache.entry[index];
1089 }
1090 
1091 /* When called from virtmode, this func should be protected by
1092  * preempt_disable(), otherwise, the holding of HPTE_V_HVLOCK
1093  * can trigger deadlock issue.
1094  */
1095 long kvmppc_hv_find_lock_hpte(struct kvm *kvm, gva_t eaddr, unsigned long slb_v,
1096 			      unsigned long valid)
1097 {
1098 	unsigned int i;
1099 	unsigned int pshift;
1100 	unsigned long somask;
1101 	unsigned long vsid, hash;
1102 	unsigned long avpn;
1103 	__be64 *hpte;
1104 	unsigned long mask, val;
1105 	unsigned long v, r, orig_v;
1106 
1107 	/* Get page shift, work out hash and AVPN etc. */
1108 	mask = SLB_VSID_B | HPTE_V_AVPN | HPTE_V_SECONDARY;
1109 	val = 0;
1110 	pshift = 12;
1111 	if (slb_v & SLB_VSID_L) {
1112 		mask |= HPTE_V_LARGE;
1113 		val |= HPTE_V_LARGE;
1114 		pshift = slb_base_page_shift[(slb_v & SLB_VSID_LP) >> 4];
1115 	}
1116 	if (slb_v & SLB_VSID_B_1T) {
1117 		somask = (1UL << 40) - 1;
1118 		vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT_1T;
1119 		vsid ^= vsid << 25;
1120 	} else {
1121 		somask = (1UL << 28) - 1;
1122 		vsid = (slb_v & ~SLB_VSID_B) >> SLB_VSID_SHIFT;
1123 	}
1124 	hash = (vsid ^ ((eaddr & somask) >> pshift)) & kvmppc_hpt_mask(&kvm->arch.hpt);
1125 	avpn = slb_v & ~(somask >> 16);	/* also includes B */
1126 	avpn |= (eaddr & somask) >> 16;
1127 
1128 	if (pshift >= 24)
1129 		avpn &= ~((1UL << (pshift - 16)) - 1);
1130 	else
1131 		avpn &= ~0x7fUL;
1132 	val |= avpn;
1133 
1134 	for (;;) {
1135 		hpte = (__be64 *)(kvm->arch.hpt.virt + (hash << 7));
1136 
1137 		for (i = 0; i < 16; i += 2) {
1138 			/* Read the PTE racily */
1139 			v = be64_to_cpu(hpte[i]) & ~HPTE_V_HVLOCK;
1140 			if (cpu_has_feature(CPU_FTR_ARCH_300))
1141 				v = hpte_new_to_old_v(v, be64_to_cpu(hpte[i+1]));
1142 
1143 			/* Check valid/absent, hash, segment size and AVPN */
1144 			if (!(v & valid) || (v & mask) != val)
1145 				continue;
1146 
1147 			/* Lock the PTE and read it under the lock */
1148 			while (!try_lock_hpte(&hpte[i], HPTE_V_HVLOCK))
1149 				cpu_relax();
1150 			v = orig_v = be64_to_cpu(hpte[i]) & ~HPTE_V_HVLOCK;
1151 			r = be64_to_cpu(hpte[i+1]);
1152 			if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1153 				v = hpte_new_to_old_v(v, r);
1154 				r = hpte_new_to_old_r(r);
1155 			}
1156 
1157 			/*
1158 			 * Check the HPTE again, including base page size
1159 			 */
1160 			if ((v & valid) && (v & mask) == val &&
1161 			    kvmppc_hpte_base_page_shift(v, r) == pshift)
1162 				/* Return with the HPTE still locked */
1163 				return (hash << 3) + (i >> 1);
1164 
1165 			__unlock_hpte(&hpte[i], orig_v);
1166 		}
1167 
1168 		if (val & HPTE_V_SECONDARY)
1169 			break;
1170 		val |= HPTE_V_SECONDARY;
1171 		hash = hash ^ kvmppc_hpt_mask(&kvm->arch.hpt);
1172 	}
1173 	return -1;
1174 }
1175 EXPORT_SYMBOL(kvmppc_hv_find_lock_hpte);
1176 
1177 /*
1178  * Called in real mode to check whether an HPTE not found fault
1179  * is due to accessing a paged-out page or an emulated MMIO page,
1180  * or if a protection fault is due to accessing a page that the
1181  * guest wanted read/write access to but which we made read-only.
1182  * Returns a possibly modified status (DSISR) value if not
1183  * (i.e. pass the interrupt to the guest),
1184  * -1 to pass the fault up to host kernel mode code, -2 to do that
1185  * and also load the instruction word (for MMIO emulation),
1186  * or 0 if we should make the guest retry the access.
1187  */
1188 long kvmppc_hpte_hv_fault(struct kvm_vcpu *vcpu, unsigned long addr,
1189 			  unsigned long slb_v, unsigned int status, bool data)
1190 {
1191 	struct kvm *kvm = vcpu->kvm;
1192 	long int index;
1193 	unsigned long v, r, gr, orig_v;
1194 	__be64 *hpte;
1195 	unsigned long valid;
1196 	struct revmap_entry *rev;
1197 	unsigned long pp, key;
1198 	struct mmio_hpte_cache_entry *cache_entry = NULL;
1199 	long mmio_update = 0;
1200 
1201 	/* For protection fault, expect to find a valid HPTE */
1202 	valid = HPTE_V_VALID;
1203 	if (status & DSISR_NOHPTE) {
1204 		valid |= HPTE_V_ABSENT;
1205 		mmio_update = atomic64_read(&kvm->arch.mmio_update);
1206 		cache_entry = mmio_cache_search(vcpu, addr, slb_v, mmio_update);
1207 	}
1208 	if (cache_entry) {
1209 		index = cache_entry->pte_index;
1210 		v = cache_entry->hpte_v;
1211 		r = cache_entry->hpte_r;
1212 		gr = cache_entry->rpte;
1213 	} else {
1214 		index = kvmppc_hv_find_lock_hpte(kvm, addr, slb_v, valid);
1215 		if (index < 0) {
1216 			if (status & DSISR_NOHPTE)
1217 				return status;	/* there really was no HPTE */
1218 			return 0;	/* for prot fault, HPTE disappeared */
1219 		}
1220 		hpte = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
1221 		v = orig_v = be64_to_cpu(hpte[0]) & ~HPTE_V_HVLOCK;
1222 		r = be64_to_cpu(hpte[1]);
1223 		if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1224 			v = hpte_new_to_old_v(v, r);
1225 			r = hpte_new_to_old_r(r);
1226 		}
1227 		rev = real_vmalloc_addr(&kvm->arch.hpt.rev[index]);
1228 		gr = rev->guest_rpte;
1229 
1230 		unlock_hpte(hpte, orig_v);
1231 	}
1232 
1233 	/* For not found, if the HPTE is valid by now, retry the instruction */
1234 	if ((status & DSISR_NOHPTE) && (v & HPTE_V_VALID))
1235 		return 0;
1236 
1237 	/* Check access permissions to the page */
1238 	pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
1239 	key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
1240 	status &= ~DSISR_NOHPTE;	/* DSISR_NOHPTE == SRR1_ISI_NOPT */
1241 	if (!data) {
1242 		if (gr & (HPTE_R_N | HPTE_R_G))
1243 			return status | SRR1_ISI_N_G_OR_CIP;
1244 		if (!hpte_read_permission(pp, slb_v & key))
1245 			return status | SRR1_ISI_PROT;
1246 	} else if (status & DSISR_ISSTORE) {
1247 		/* check write permission */
1248 		if (!hpte_write_permission(pp, slb_v & key))
1249 			return status | DSISR_PROTFAULT;
1250 	} else {
1251 		if (!hpte_read_permission(pp, slb_v & key))
1252 			return status | DSISR_PROTFAULT;
1253 	}
1254 
1255 	/* Check storage key, if applicable */
1256 	if (data && (vcpu->arch.shregs.msr & MSR_DR)) {
1257 		unsigned int perm = hpte_get_skey_perm(gr, vcpu->arch.amr);
1258 		if (status & DSISR_ISSTORE)
1259 			perm >>= 1;
1260 		if (perm & 1)
1261 			return status | DSISR_KEYFAULT;
1262 	}
1263 
1264 	/* Save HPTE info for virtual-mode handler */
1265 	vcpu->arch.pgfault_addr = addr;
1266 	vcpu->arch.pgfault_index = index;
1267 	vcpu->arch.pgfault_hpte[0] = v;
1268 	vcpu->arch.pgfault_hpte[1] = r;
1269 	vcpu->arch.pgfault_cache = cache_entry;
1270 
1271 	/* Check the storage key to see if it is possibly emulated MMIO */
1272 	if ((r & (HPTE_R_KEY_HI | HPTE_R_KEY_LO)) ==
1273 	    (HPTE_R_KEY_HI | HPTE_R_KEY_LO)) {
1274 		if (!cache_entry) {
1275 			unsigned int pshift = 12;
1276 			unsigned int pshift_index;
1277 
1278 			if (slb_v & SLB_VSID_L) {
1279 				pshift_index = ((slb_v & SLB_VSID_LP) >> 4);
1280 				pshift = slb_base_page_shift[pshift_index];
1281 			}
1282 			cache_entry = next_mmio_cache_entry(vcpu);
1283 			cache_entry->eaddr = addr;
1284 			cache_entry->slb_base_pshift = pshift;
1285 			cache_entry->pte_index = index;
1286 			cache_entry->hpte_v = v;
1287 			cache_entry->hpte_r = r;
1288 			cache_entry->rpte = gr;
1289 			cache_entry->slb_v = slb_v;
1290 			cache_entry->mmio_update = mmio_update;
1291 		}
1292 		if (data && (vcpu->arch.shregs.msr & MSR_IR))
1293 			return -2;	/* MMIO emulation - load instr word */
1294 	}
1295 
1296 	return -1;		/* send fault up to host kernel mode */
1297 }
1298