1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Copyright 2016 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/anon_inodes.h>
12 #include <linux/file.h>
13 #include <linux/debugfs.h>
14 
15 #include <asm/kvm_ppc.h>
16 #include <asm/kvm_book3s.h>
17 #include <asm/page.h>
18 #include <asm/mmu.h>
19 #include <asm/pgtable.h>
20 #include <asm/pgalloc.h>
21 #include <asm/pte-walk.h>
22 #include <asm/ultravisor.h>
23 #include <asm/kvm_book3s_uvmem.h>
24 
25 /*
26  * Supported radix tree geometry.
27  * Like p9, we support either 5 or 9 bits at the first (lowest) level,
28  * for a page size of 64k or 4k.
29  */
30 static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
31 
32 unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
33 					      gva_t eaddr, void *to, void *from,
34 					      unsigned long n)
35 {
36 	int uninitialized_var(old_pid), old_lpid;
37 	unsigned long quadrant, ret = n;
38 	bool is_load = !!to;
39 
40 	/* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */
41 	if (kvmhv_on_pseries())
42 		return plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr,
43 					  __pa(to), __pa(from), n);
44 
45 	quadrant = 1;
46 	if (!pid)
47 		quadrant = 2;
48 	if (is_load)
49 		from = (void *) (eaddr | (quadrant << 62));
50 	else
51 		to = (void *) (eaddr | (quadrant << 62));
52 
53 	preempt_disable();
54 
55 	/* switch the lpid first to avoid running host with unallocated pid */
56 	old_lpid = mfspr(SPRN_LPID);
57 	if (old_lpid != lpid)
58 		mtspr(SPRN_LPID, lpid);
59 	if (quadrant == 1) {
60 		old_pid = mfspr(SPRN_PID);
61 		if (old_pid != pid)
62 			mtspr(SPRN_PID, pid);
63 	}
64 	isync();
65 
66 	if (is_load)
67 		ret = probe_user_read(to, (const void __user *)from, n);
68 	else
69 		ret = probe_user_write((void __user *)to, from, n);
70 
71 	/* switch the pid first to avoid running host with unallocated pid */
72 	if (quadrant == 1 && pid != old_pid)
73 		mtspr(SPRN_PID, old_pid);
74 	if (lpid != old_lpid)
75 		mtspr(SPRN_LPID, old_lpid);
76 	isync();
77 
78 	preempt_enable();
79 
80 	return ret;
81 }
82 EXPORT_SYMBOL_GPL(__kvmhv_copy_tofrom_guest_radix);
83 
84 static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
85 					  void *to, void *from, unsigned long n)
86 {
87 	int lpid = vcpu->kvm->arch.lpid;
88 	int pid = vcpu->arch.pid;
89 
90 	/* This would cause a data segment intr so don't allow the access */
91 	if (eaddr & (0x3FFUL << 52))
92 		return -EINVAL;
93 
94 	/* Should we be using the nested lpid */
95 	if (vcpu->arch.nested)
96 		lpid = vcpu->arch.nested->shadow_lpid;
97 
98 	/* If accessing quadrant 3 then pid is expected to be 0 */
99 	if (((eaddr >> 62) & 0x3) == 0x3)
100 		pid = 0;
101 
102 	eaddr &= ~(0xFFFUL << 52);
103 
104 	return __kvmhv_copy_tofrom_guest_radix(lpid, pid, eaddr, to, from, n);
105 }
106 
107 long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to,
108 				 unsigned long n)
109 {
110 	long ret;
111 
112 	ret = kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, to, NULL, n);
113 	if (ret > 0)
114 		memset(to + (n - ret), 0, ret);
115 
116 	return ret;
117 }
118 EXPORT_SYMBOL_GPL(kvmhv_copy_from_guest_radix);
119 
120 long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *from,
121 			       unsigned long n)
122 {
123 	return kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, NULL, from, n);
124 }
125 EXPORT_SYMBOL_GPL(kvmhv_copy_to_guest_radix);
126 
127 int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr,
128 			       struct kvmppc_pte *gpte, u64 root,
129 			       u64 *pte_ret_p)
130 {
131 	struct kvm *kvm = vcpu->kvm;
132 	int ret, level, ps;
133 	unsigned long rts, bits, offset, index;
134 	u64 pte, base, gpa;
135 	__be64 rpte;
136 
137 	rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
138 		((root & RTS2_MASK) >> RTS2_SHIFT);
139 	bits = root & RPDS_MASK;
140 	base = root & RPDB_MASK;
141 
142 	offset = rts + 31;
143 
144 	/* Current implementations only support 52-bit space */
145 	if (offset != 52)
146 		return -EINVAL;
147 
148 	/* Walk each level of the radix tree */
149 	for (level = 3; level >= 0; --level) {
150 		u64 addr;
151 		/* Check a valid size */
152 		if (level && bits != p9_supported_radix_bits[level])
153 			return -EINVAL;
154 		if (level == 0 && !(bits == 5 || bits == 9))
155 			return -EINVAL;
156 		offset -= bits;
157 		index = (eaddr >> offset) & ((1UL << bits) - 1);
158 		/* Check that low bits of page table base are zero */
159 		if (base & ((1UL << (bits + 3)) - 1))
160 			return -EINVAL;
161 		/* Read the entry from guest memory */
162 		addr = base + (index * sizeof(rpte));
163 		ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte));
164 		if (ret) {
165 			if (pte_ret_p)
166 				*pte_ret_p = addr;
167 			return ret;
168 		}
169 		pte = __be64_to_cpu(rpte);
170 		if (!(pte & _PAGE_PRESENT))
171 			return -ENOENT;
172 		/* Check if a leaf entry */
173 		if (pte & _PAGE_PTE)
174 			break;
175 		/* Get ready to walk the next level */
176 		base = pte & RPDB_MASK;
177 		bits = pte & RPDS_MASK;
178 	}
179 
180 	/* Need a leaf at lowest level; 512GB pages not supported */
181 	if (level < 0 || level == 3)
182 		return -EINVAL;
183 
184 	/* We found a valid leaf PTE */
185 	/* Offset is now log base 2 of the page size */
186 	gpa = pte & 0x01fffffffffff000ul;
187 	if (gpa & ((1ul << offset) - 1))
188 		return -EINVAL;
189 	gpa |= eaddr & ((1ul << offset) - 1);
190 	for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps)
191 		if (offset == mmu_psize_defs[ps].shift)
192 			break;
193 	gpte->page_size = ps;
194 	gpte->page_shift = offset;
195 
196 	gpte->eaddr = eaddr;
197 	gpte->raddr = gpa;
198 
199 	/* Work out permissions */
200 	gpte->may_read = !!(pte & _PAGE_READ);
201 	gpte->may_write = !!(pte & _PAGE_WRITE);
202 	gpte->may_execute = !!(pte & _PAGE_EXEC);
203 
204 	gpte->rc = pte & (_PAGE_ACCESSED | _PAGE_DIRTY);
205 
206 	if (pte_ret_p)
207 		*pte_ret_p = pte;
208 
209 	return 0;
210 }
211 
212 /*
213  * Used to walk a partition or process table radix tree in guest memory
214  * Note: We exploit the fact that a partition table and a process
215  * table have the same layout, a partition-scoped page table and a
216  * process-scoped page table have the same layout, and the 2nd
217  * doubleword of a partition table entry has the same layout as
218  * the PTCR register.
219  */
220 int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
221 				     struct kvmppc_pte *gpte, u64 table,
222 				     int table_index, u64 *pte_ret_p)
223 {
224 	struct kvm *kvm = vcpu->kvm;
225 	int ret;
226 	unsigned long size, ptbl, root;
227 	struct prtb_entry entry;
228 
229 	if ((table & PRTS_MASK) > 24)
230 		return -EINVAL;
231 	size = 1ul << ((table & PRTS_MASK) + 12);
232 
233 	/* Is the table big enough to contain this entry? */
234 	if ((table_index * sizeof(entry)) >= size)
235 		return -EINVAL;
236 
237 	/* Read the table to find the root of the radix tree */
238 	ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry));
239 	ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry));
240 	if (ret)
241 		return ret;
242 
243 	/* Root is stored in the first double word */
244 	root = be64_to_cpu(entry.prtb0);
245 
246 	return kvmppc_mmu_walk_radix_tree(vcpu, eaddr, gpte, root, pte_ret_p);
247 }
248 
249 int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
250 			   struct kvmppc_pte *gpte, bool data, bool iswrite)
251 {
252 	u32 pid;
253 	u64 pte;
254 	int ret;
255 
256 	/* Work out effective PID */
257 	switch (eaddr >> 62) {
258 	case 0:
259 		pid = vcpu->arch.pid;
260 		break;
261 	case 3:
262 		pid = 0;
263 		break;
264 	default:
265 		return -EINVAL;
266 	}
267 
268 	ret = kvmppc_mmu_radix_translate_table(vcpu, eaddr, gpte,
269 				vcpu->kvm->arch.process_table, pid, &pte);
270 	if (ret)
271 		return ret;
272 
273 	/* Check privilege (applies only to process scoped translations) */
274 	if (kvmppc_get_msr(vcpu) & MSR_PR) {
275 		if (pte & _PAGE_PRIVILEGED) {
276 			gpte->may_read = 0;
277 			gpte->may_write = 0;
278 			gpte->may_execute = 0;
279 		}
280 	} else {
281 		if (!(pte & _PAGE_PRIVILEGED)) {
282 			/* Check AMR/IAMR to see if strict mode is in force */
283 			if (vcpu->arch.amr & (1ul << 62))
284 				gpte->may_read = 0;
285 			if (vcpu->arch.amr & (1ul << 63))
286 				gpte->may_write = 0;
287 			if (vcpu->arch.iamr & (1ul << 62))
288 				gpte->may_execute = 0;
289 		}
290 	}
291 
292 	return 0;
293 }
294 
295 void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
296 			     unsigned int pshift, unsigned int lpid)
297 {
298 	unsigned long psize = PAGE_SIZE;
299 	int psi;
300 	long rc;
301 	unsigned long rb;
302 
303 	if (pshift)
304 		psize = 1UL << pshift;
305 	else
306 		pshift = PAGE_SHIFT;
307 
308 	addr &= ~(psize - 1);
309 
310 	if (!kvmhv_on_pseries()) {
311 		radix__flush_tlb_lpid_page(lpid, addr, psize);
312 		return;
313 	}
314 
315 	psi = shift_to_mmu_psize(pshift);
316 	rb = addr | (mmu_get_ap(psi) << PPC_BITLSHIFT(58));
317 	rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(0, 0, 1),
318 				lpid, rb);
319 	if (rc)
320 		pr_err("KVM: TLB page invalidation hcall failed, rc=%ld\n", rc);
321 }
322 
323 static void kvmppc_radix_flush_pwc(struct kvm *kvm, unsigned int lpid)
324 {
325 	long rc;
326 
327 	if (!kvmhv_on_pseries()) {
328 		radix__flush_pwc_lpid(lpid);
329 		return;
330 	}
331 
332 	rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(1, 0, 1),
333 				lpid, TLBIEL_INVAL_SET_LPID);
334 	if (rc)
335 		pr_err("KVM: TLB PWC invalidation hcall failed, rc=%ld\n", rc);
336 }
337 
338 static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep,
339 				      unsigned long clr, unsigned long set,
340 				      unsigned long addr, unsigned int shift)
341 {
342 	return __radix_pte_update(ptep, clr, set);
343 }
344 
345 void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr,
346 			     pte_t *ptep, pte_t pte)
347 {
348 	radix__set_pte_at(kvm->mm, addr, ptep, pte, 0);
349 }
350 
351 static struct kmem_cache *kvm_pte_cache;
352 static struct kmem_cache *kvm_pmd_cache;
353 
354 static pte_t *kvmppc_pte_alloc(void)
355 {
356 	return kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL);
357 }
358 
359 static void kvmppc_pte_free(pte_t *ptep)
360 {
361 	kmem_cache_free(kvm_pte_cache, ptep);
362 }
363 
364 static pmd_t *kvmppc_pmd_alloc(void)
365 {
366 	return kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL);
367 }
368 
369 static void kvmppc_pmd_free(pmd_t *pmdp)
370 {
371 	kmem_cache_free(kvm_pmd_cache, pmdp);
372 }
373 
374 /* Called with kvm->mmu_lock held */
375 void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, unsigned long gpa,
376 		      unsigned int shift,
377 		      const struct kvm_memory_slot *memslot,
378 		      unsigned int lpid)
379 
380 {
381 	unsigned long old;
382 	unsigned long gfn = gpa >> PAGE_SHIFT;
383 	unsigned long page_size = PAGE_SIZE;
384 	unsigned long hpa;
385 
386 	old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift);
387 	kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
388 
389 	/* The following only applies to L1 entries */
390 	if (lpid != kvm->arch.lpid)
391 		return;
392 
393 	if (!memslot) {
394 		memslot = gfn_to_memslot(kvm, gfn);
395 		if (!memslot)
396 			return;
397 	}
398 	if (shift) { /* 1GB or 2MB page */
399 		page_size = 1ul << shift;
400 		if (shift == PMD_SHIFT)
401 			kvm->stat.num_2M_pages--;
402 		else if (shift == PUD_SHIFT)
403 			kvm->stat.num_1G_pages--;
404 	}
405 
406 	gpa &= ~(page_size - 1);
407 	hpa = old & PTE_RPN_MASK;
408 	kvmhv_remove_nest_rmap_range(kvm, memslot, gpa, hpa, page_size);
409 
410 	if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap)
411 		kvmppc_update_dirty_map(memslot, gfn, page_size);
412 }
413 
414 /*
415  * kvmppc_free_p?d are used to free existing page tables, and recursively
416  * descend and clear and free children.
417  * Callers are responsible for flushing the PWC.
418  *
419  * When page tables are being unmapped/freed as part of page fault path
420  * (full == false), ptes are not expected. There is code to unmap them
421  * and emit a warning if encountered, but there may already be data
422  * corruption due to the unexpected mappings.
423  */
424 static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full,
425 				  unsigned int lpid)
426 {
427 	if (full) {
428 		memset(pte, 0, sizeof(long) << RADIX_PTE_INDEX_SIZE);
429 	} else {
430 		pte_t *p = pte;
431 		unsigned long it;
432 
433 		for (it = 0; it < PTRS_PER_PTE; ++it, ++p) {
434 			if (pte_val(*p) == 0)
435 				continue;
436 			WARN_ON_ONCE(1);
437 			kvmppc_unmap_pte(kvm, p,
438 					 pte_pfn(*p) << PAGE_SHIFT,
439 					 PAGE_SHIFT, NULL, lpid);
440 		}
441 	}
442 
443 	kvmppc_pte_free(pte);
444 }
445 
446 static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
447 				  unsigned int lpid)
448 {
449 	unsigned long im;
450 	pmd_t *p = pmd;
451 
452 	for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
453 		if (!pmd_present(*p))
454 			continue;
455 		if (pmd_is_leaf(*p)) {
456 			if (full) {
457 				pmd_clear(p);
458 			} else {
459 				WARN_ON_ONCE(1);
460 				kvmppc_unmap_pte(kvm, (pte_t *)p,
461 					 pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
462 					 PMD_SHIFT, NULL, lpid);
463 			}
464 		} else {
465 			pte_t *pte;
466 
467 			pte = pte_offset_map(p, 0);
468 			kvmppc_unmap_free_pte(kvm, pte, full, lpid);
469 			pmd_clear(p);
470 		}
471 	}
472 	kvmppc_pmd_free(pmd);
473 }
474 
475 static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud,
476 				  unsigned int lpid)
477 {
478 	unsigned long iu;
479 	pud_t *p = pud;
480 
481 	for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) {
482 		if (!pud_present(*p))
483 			continue;
484 		if (pud_is_leaf(*p)) {
485 			pud_clear(p);
486 		} else {
487 			pmd_t *pmd;
488 
489 			pmd = pmd_offset(p, 0);
490 			kvmppc_unmap_free_pmd(kvm, pmd, true, lpid);
491 			pud_clear(p);
492 		}
493 	}
494 	pud_free(kvm->mm, pud);
495 }
496 
497 void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, unsigned int lpid)
498 {
499 	unsigned long ig;
500 
501 	for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
502 		p4d_t *p4d = p4d_offset(pgd, 0);
503 		pud_t *pud;
504 
505 		if (!p4d_present(*p4d))
506 			continue;
507 		pud = pud_offset(p4d, 0);
508 		kvmppc_unmap_free_pud(kvm, pud, lpid);
509 		p4d_clear(p4d);
510 	}
511 }
512 
513 void kvmppc_free_radix(struct kvm *kvm)
514 {
515 	if (kvm->arch.pgtable) {
516 		kvmppc_free_pgtable_radix(kvm, kvm->arch.pgtable,
517 					  kvm->arch.lpid);
518 		pgd_free(kvm->mm, kvm->arch.pgtable);
519 		kvm->arch.pgtable = NULL;
520 	}
521 }
522 
523 static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd,
524 					unsigned long gpa, unsigned int lpid)
525 {
526 	pte_t *pte = pte_offset_kernel(pmd, 0);
527 
528 	/*
529 	 * Clearing the pmd entry then flushing the PWC ensures that the pte
530 	 * page no longer be cached by the MMU, so can be freed without
531 	 * flushing the PWC again.
532 	 */
533 	pmd_clear(pmd);
534 	kvmppc_radix_flush_pwc(kvm, lpid);
535 
536 	kvmppc_unmap_free_pte(kvm, pte, false, lpid);
537 }
538 
539 static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
540 					unsigned long gpa, unsigned int lpid)
541 {
542 	pmd_t *pmd = pmd_offset(pud, 0);
543 
544 	/*
545 	 * Clearing the pud entry then flushing the PWC ensures that the pmd
546 	 * page and any children pte pages will no longer be cached by the MMU,
547 	 * so can be freed without flushing the PWC again.
548 	 */
549 	pud_clear(pud);
550 	kvmppc_radix_flush_pwc(kvm, lpid);
551 
552 	kvmppc_unmap_free_pmd(kvm, pmd, false, lpid);
553 }
554 
555 /*
556  * There are a number of bits which may differ between different faults to
557  * the same partition scope entry. RC bits, in the course of cleaning and
558  * aging. And the write bit can change, either the access could have been
559  * upgraded, or a read fault could happen concurrently with a write fault
560  * that sets those bits first.
561  */
562 #define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED))
563 
564 int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
565 		      unsigned long gpa, unsigned int level,
566 		      unsigned long mmu_seq, unsigned int lpid,
567 		      unsigned long *rmapp, struct rmap_nested **n_rmap)
568 {
569 	pgd_t *pgd;
570 	p4d_t *p4d;
571 	pud_t *pud, *new_pud = NULL;
572 	pmd_t *pmd, *new_pmd = NULL;
573 	pte_t *ptep, *new_ptep = NULL;
574 	int ret;
575 
576 	/* Traverse the guest's 2nd-level tree, allocate new levels needed */
577 	pgd = pgtable + pgd_index(gpa);
578 	p4d = p4d_offset(pgd, gpa);
579 
580 	pud = NULL;
581 	if (p4d_present(*p4d))
582 		pud = pud_offset(p4d, gpa);
583 	else
584 		new_pud = pud_alloc_one(kvm->mm, gpa);
585 
586 	pmd = NULL;
587 	if (pud && pud_present(*pud) && !pud_is_leaf(*pud))
588 		pmd = pmd_offset(pud, gpa);
589 	else if (level <= 1)
590 		new_pmd = kvmppc_pmd_alloc();
591 
592 	if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
593 		new_ptep = kvmppc_pte_alloc();
594 
595 	/* Check if we might have been invalidated; let the guest retry if so */
596 	spin_lock(&kvm->mmu_lock);
597 	ret = -EAGAIN;
598 	if (mmu_notifier_retry(kvm, mmu_seq))
599 		goto out_unlock;
600 
601 	/* Now traverse again under the lock and change the tree */
602 	ret = -ENOMEM;
603 	if (p4d_none(*p4d)) {
604 		if (!new_pud)
605 			goto out_unlock;
606 		p4d_populate(kvm->mm, p4d, new_pud);
607 		new_pud = NULL;
608 	}
609 	pud = pud_offset(p4d, gpa);
610 	if (pud_is_leaf(*pud)) {
611 		unsigned long hgpa = gpa & PUD_MASK;
612 
613 		/* Check if we raced and someone else has set the same thing */
614 		if (level == 2) {
615 			if (pud_raw(*pud) == pte_raw(pte)) {
616 				ret = 0;
617 				goto out_unlock;
618 			}
619 			/* Valid 1GB page here already, add our extra bits */
620 			WARN_ON_ONCE((pud_val(*pud) ^ pte_val(pte)) &
621 							PTE_BITS_MUST_MATCH);
622 			kvmppc_radix_update_pte(kvm, (pte_t *)pud,
623 					      0, pte_val(pte), hgpa, PUD_SHIFT);
624 			ret = 0;
625 			goto out_unlock;
626 		}
627 		/*
628 		 * If we raced with another CPU which has just put
629 		 * a 1GB pte in after we saw a pmd page, try again.
630 		 */
631 		if (!new_pmd) {
632 			ret = -EAGAIN;
633 			goto out_unlock;
634 		}
635 		/* Valid 1GB page here already, remove it */
636 		kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL,
637 				 lpid);
638 	}
639 	if (level == 2) {
640 		if (!pud_none(*pud)) {
641 			/*
642 			 * There's a page table page here, but we wanted to
643 			 * install a large page, so remove and free the page
644 			 * table page.
645 			 */
646 			kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa, lpid);
647 		}
648 		kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte);
649 		if (rmapp && n_rmap)
650 			kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
651 		ret = 0;
652 		goto out_unlock;
653 	}
654 	if (pud_none(*pud)) {
655 		if (!new_pmd)
656 			goto out_unlock;
657 		pud_populate(kvm->mm, pud, new_pmd);
658 		new_pmd = NULL;
659 	}
660 	pmd = pmd_offset(pud, gpa);
661 	if (pmd_is_leaf(*pmd)) {
662 		unsigned long lgpa = gpa & PMD_MASK;
663 
664 		/* Check if we raced and someone else has set the same thing */
665 		if (level == 1) {
666 			if (pmd_raw(*pmd) == pte_raw(pte)) {
667 				ret = 0;
668 				goto out_unlock;
669 			}
670 			/* Valid 2MB page here already, add our extra bits */
671 			WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) &
672 							PTE_BITS_MUST_MATCH);
673 			kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd),
674 					0, pte_val(pte), lgpa, PMD_SHIFT);
675 			ret = 0;
676 			goto out_unlock;
677 		}
678 
679 		/*
680 		 * If we raced with another CPU which has just put
681 		 * a 2MB pte in after we saw a pte page, try again.
682 		 */
683 		if (!new_ptep) {
684 			ret = -EAGAIN;
685 			goto out_unlock;
686 		}
687 		/* Valid 2MB page here already, remove it */
688 		kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL,
689 				 lpid);
690 	}
691 	if (level == 1) {
692 		if (!pmd_none(*pmd)) {
693 			/*
694 			 * There's a page table page here, but we wanted to
695 			 * install a large page, so remove and free the page
696 			 * table page.
697 			 */
698 			kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa, lpid);
699 		}
700 		kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
701 		if (rmapp && n_rmap)
702 			kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
703 		ret = 0;
704 		goto out_unlock;
705 	}
706 	if (pmd_none(*pmd)) {
707 		if (!new_ptep)
708 			goto out_unlock;
709 		pmd_populate(kvm->mm, pmd, new_ptep);
710 		new_ptep = NULL;
711 	}
712 	ptep = pte_offset_kernel(pmd, gpa);
713 	if (pte_present(*ptep)) {
714 		/* Check if someone else set the same thing */
715 		if (pte_raw(*ptep) == pte_raw(pte)) {
716 			ret = 0;
717 			goto out_unlock;
718 		}
719 		/* Valid page here already, add our extra bits */
720 		WARN_ON_ONCE((pte_val(*ptep) ^ pte_val(pte)) &
721 							PTE_BITS_MUST_MATCH);
722 		kvmppc_radix_update_pte(kvm, ptep, 0, pte_val(pte), gpa, 0);
723 		ret = 0;
724 		goto out_unlock;
725 	}
726 	kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte);
727 	if (rmapp && n_rmap)
728 		kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
729 	ret = 0;
730 
731  out_unlock:
732 	spin_unlock(&kvm->mmu_lock);
733 	if (new_pud)
734 		pud_free(kvm->mm, new_pud);
735 	if (new_pmd)
736 		kvmppc_pmd_free(new_pmd);
737 	if (new_ptep)
738 		kvmppc_pte_free(new_ptep);
739 	return ret;
740 }
741 
742 bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable, bool writing,
743 			     unsigned long gpa, unsigned int lpid)
744 {
745 	unsigned long pgflags;
746 	unsigned int shift;
747 	pte_t *ptep;
748 
749 	/*
750 	 * Need to set an R or C bit in the 2nd-level tables;
751 	 * since we are just helping out the hardware here,
752 	 * it is sufficient to do what the hardware does.
753 	 */
754 	pgflags = _PAGE_ACCESSED;
755 	if (writing)
756 		pgflags |= _PAGE_DIRTY;
757 	/*
758 	 * We are walking the secondary (partition-scoped) page table here.
759 	 * We can do this without disabling irq because the Linux MM
760 	 * subsystem doesn't do THP splits and collapses on this tree.
761 	 */
762 	ptep = __find_linux_pte(pgtable, gpa, NULL, &shift);
763 	if (ptep && pte_present(*ptep) && (!writing || pte_write(*ptep))) {
764 		kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, gpa, shift);
765 		return true;
766 	}
767 	return false;
768 }
769 
770 int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
771 				   unsigned long gpa,
772 				   struct kvm_memory_slot *memslot,
773 				   bool writing, bool kvm_ro,
774 				   pte_t *inserted_pte, unsigned int *levelp)
775 {
776 	struct kvm *kvm = vcpu->kvm;
777 	struct page *page = NULL;
778 	unsigned long mmu_seq;
779 	unsigned long hva, gfn = gpa >> PAGE_SHIFT;
780 	bool upgrade_write = false;
781 	bool *upgrade_p = &upgrade_write;
782 	pte_t pte, *ptep;
783 	unsigned int shift, level;
784 	int ret;
785 	bool large_enable;
786 
787 	/* used to check for invalidations in progress */
788 	mmu_seq = kvm->mmu_notifier_seq;
789 	smp_rmb();
790 
791 	/*
792 	 * Do a fast check first, since __gfn_to_pfn_memslot doesn't
793 	 * do it with !atomic && !async, which is how we call it.
794 	 * We always ask for write permission since the common case
795 	 * is that the page is writable.
796 	 */
797 	hva = gfn_to_hva_memslot(memslot, gfn);
798 	if (!kvm_ro && __get_user_pages_fast(hva, 1, 1, &page) == 1) {
799 		upgrade_write = true;
800 	} else {
801 		unsigned long pfn;
802 
803 		/* Call KVM generic code to do the slow-path check */
804 		pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL,
805 					   writing, upgrade_p);
806 		if (is_error_noslot_pfn(pfn))
807 			return -EFAULT;
808 		page = NULL;
809 		if (pfn_valid(pfn)) {
810 			page = pfn_to_page(pfn);
811 			if (PageReserved(page))
812 				page = NULL;
813 		}
814 	}
815 
816 	/*
817 	 * Read the PTE from the process' radix tree and use that
818 	 * so we get the shift and attribute bits.
819 	 */
820 	local_irq_disable();
821 	ptep = __find_linux_pte(vcpu->arch.pgdir, hva, NULL, &shift);
822 	pte = __pte(0);
823 	if (ptep)
824 		pte = *ptep;
825 	local_irq_enable();
826 	/*
827 	 * If the PTE disappeared temporarily due to a THP
828 	 * collapse, just return and let the guest try again.
829 	 */
830 	if (!pte_present(pte)) {
831 		if (page)
832 			put_page(page);
833 		return RESUME_GUEST;
834 	}
835 
836 	/* If we're logging dirty pages, always map single pages */
837 	large_enable = !(memslot->flags & KVM_MEM_LOG_DIRTY_PAGES);
838 
839 	/* Get pte level from shift/size */
840 	if (large_enable && shift == PUD_SHIFT &&
841 	    (gpa & (PUD_SIZE - PAGE_SIZE)) ==
842 	    (hva & (PUD_SIZE - PAGE_SIZE))) {
843 		level = 2;
844 	} else if (large_enable && shift == PMD_SHIFT &&
845 		   (gpa & (PMD_SIZE - PAGE_SIZE)) ==
846 		   (hva & (PMD_SIZE - PAGE_SIZE))) {
847 		level = 1;
848 	} else {
849 		level = 0;
850 		if (shift > PAGE_SHIFT) {
851 			/*
852 			 * If the pte maps more than one page, bring over
853 			 * bits from the virtual address to get the real
854 			 * address of the specific single page we want.
855 			 */
856 			unsigned long rpnmask = (1ul << shift) - PAGE_SIZE;
857 			pte = __pte(pte_val(pte) | (hva & rpnmask));
858 		}
859 	}
860 
861 	pte = __pte(pte_val(pte) | _PAGE_EXEC | _PAGE_ACCESSED);
862 	if (writing || upgrade_write) {
863 		if (pte_val(pte) & _PAGE_WRITE)
864 			pte = __pte(pte_val(pte) | _PAGE_DIRTY);
865 	} else {
866 		pte = __pte(pte_val(pte) & ~(_PAGE_WRITE | _PAGE_DIRTY));
867 	}
868 
869 	/* Allocate space in the tree and write the PTE */
870 	ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level,
871 				mmu_seq, kvm->arch.lpid, NULL, NULL);
872 	if (inserted_pte)
873 		*inserted_pte = pte;
874 	if (levelp)
875 		*levelp = level;
876 
877 	if (page) {
878 		if (!ret && (pte_val(pte) & _PAGE_WRITE))
879 			set_page_dirty_lock(page);
880 		put_page(page);
881 	}
882 
883 	/* Increment number of large pages if we (successfully) inserted one */
884 	if (!ret) {
885 		if (level == 1)
886 			kvm->stat.num_2M_pages++;
887 		else if (level == 2)
888 			kvm->stat.num_1G_pages++;
889 	}
890 
891 	return ret;
892 }
893 
894 int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
895 				   unsigned long ea, unsigned long dsisr)
896 {
897 	struct kvm *kvm = vcpu->kvm;
898 	unsigned long gpa, gfn;
899 	struct kvm_memory_slot *memslot;
900 	long ret;
901 	bool writing = !!(dsisr & DSISR_ISSTORE);
902 	bool kvm_ro = false;
903 
904 	/* Check for unusual errors */
905 	if (dsisr & DSISR_UNSUPP_MMU) {
906 		pr_err("KVM: Got unsupported MMU fault\n");
907 		return -EFAULT;
908 	}
909 	if (dsisr & DSISR_BADACCESS) {
910 		/* Reflect to the guest as DSI */
911 		pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
912 		kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
913 		return RESUME_GUEST;
914 	}
915 
916 	/* Translate the logical address */
917 	gpa = vcpu->arch.fault_gpa & ~0xfffUL;
918 	gpa &= ~0xF000000000000000ul;
919 	gfn = gpa >> PAGE_SHIFT;
920 	if (!(dsisr & DSISR_PRTABLE_FAULT))
921 		gpa |= ea & 0xfff;
922 
923 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
924 		return kvmppc_send_page_to_uv(kvm, gfn);
925 
926 	/* Get the corresponding memslot */
927 	memslot = gfn_to_memslot(kvm, gfn);
928 
929 	/* No memslot means it's an emulated MMIO region */
930 	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
931 		if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
932 			     DSISR_SET_RC)) {
933 			/*
934 			 * Bad address in guest page table tree, or other
935 			 * unusual error - reflect it to the guest as DSI.
936 			 */
937 			kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
938 			return RESUME_GUEST;
939 		}
940 		return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, writing);
941 	}
942 
943 	if (memslot->flags & KVM_MEM_READONLY) {
944 		if (writing) {
945 			/* give the guest a DSI */
946 			kvmppc_core_queue_data_storage(vcpu, ea, DSISR_ISSTORE |
947 						       DSISR_PROTFAULT);
948 			return RESUME_GUEST;
949 		}
950 		kvm_ro = true;
951 	}
952 
953 	/* Failed to set the reference/change bits */
954 	if (dsisr & DSISR_SET_RC) {
955 		spin_lock(&kvm->mmu_lock);
956 		if (kvmppc_hv_handle_set_rc(kvm, kvm->arch.pgtable,
957 					    writing, gpa, kvm->arch.lpid))
958 			dsisr &= ~DSISR_SET_RC;
959 		spin_unlock(&kvm->mmu_lock);
960 
961 		if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
962 			       DSISR_PROTFAULT | DSISR_SET_RC)))
963 			return RESUME_GUEST;
964 	}
965 
966 	/* Try to insert a pte */
967 	ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, writing,
968 					     kvm_ro, NULL, NULL);
969 
970 	if (ret == 0 || ret == -EAGAIN)
971 		ret = RESUME_GUEST;
972 	return ret;
973 }
974 
975 /* Called with kvm->mmu_lock held */
976 int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
977 		    unsigned long gfn)
978 {
979 	pte_t *ptep;
980 	unsigned long gpa = gfn << PAGE_SHIFT;
981 	unsigned int shift;
982 
983 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) {
984 		uv_page_inval(kvm->arch.lpid, gpa, PAGE_SHIFT);
985 		return 0;
986 	}
987 
988 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
989 	if (ptep && pte_present(*ptep))
990 		kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
991 				 kvm->arch.lpid);
992 	return 0;
993 }
994 
995 /* Called with kvm->mmu_lock held */
996 int kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
997 		  unsigned long gfn)
998 {
999 	pte_t *ptep;
1000 	unsigned long gpa = gfn << PAGE_SHIFT;
1001 	unsigned int shift;
1002 	int ref = 0;
1003 	unsigned long old, *rmapp;
1004 
1005 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1006 		return ref;
1007 
1008 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
1009 	if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
1010 		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
1011 					      gpa, shift);
1012 		/* XXX need to flush tlb here? */
1013 		/* Also clear bit in ptes in shadow pgtable for nested guests */
1014 		rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1015 		kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_ACCESSED, 0,
1016 					       old & PTE_RPN_MASK,
1017 					       1UL << shift);
1018 		ref = 1;
1019 	}
1020 	return ref;
1021 }
1022 
1023 /* Called with kvm->mmu_lock held */
1024 int kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1025 		       unsigned long gfn)
1026 {
1027 	pte_t *ptep;
1028 	unsigned long gpa = gfn << PAGE_SHIFT;
1029 	unsigned int shift;
1030 	int ref = 0;
1031 
1032 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1033 		return ref;
1034 
1035 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
1036 	if (ptep && pte_present(*ptep) && pte_young(*ptep))
1037 		ref = 1;
1038 	return ref;
1039 }
1040 
1041 /* Returns the number of PAGE_SIZE pages that are dirty */
1042 static int kvm_radix_test_clear_dirty(struct kvm *kvm,
1043 				struct kvm_memory_slot *memslot, int pagenum)
1044 {
1045 	unsigned long gfn = memslot->base_gfn + pagenum;
1046 	unsigned long gpa = gfn << PAGE_SHIFT;
1047 	pte_t *ptep;
1048 	unsigned int shift;
1049 	int ret = 0;
1050 	unsigned long old, *rmapp;
1051 
1052 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1053 		return ret;
1054 
1055 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
1056 	if (ptep && pte_present(*ptep) && pte_dirty(*ptep)) {
1057 		ret = 1;
1058 		if (shift)
1059 			ret = 1 << (shift - PAGE_SHIFT);
1060 		spin_lock(&kvm->mmu_lock);
1061 		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,
1062 					      gpa, shift);
1063 		kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid);
1064 		/* Also clear bit in ptes in shadow pgtable for nested guests */
1065 		rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1066 		kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_DIRTY, 0,
1067 					       old & PTE_RPN_MASK,
1068 					       1UL << shift);
1069 		spin_unlock(&kvm->mmu_lock);
1070 	}
1071 	return ret;
1072 }
1073 
1074 long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm,
1075 			struct kvm_memory_slot *memslot, unsigned long *map)
1076 {
1077 	unsigned long i, j;
1078 	int npages;
1079 
1080 	for (i = 0; i < memslot->npages; i = j) {
1081 		npages = kvm_radix_test_clear_dirty(kvm, memslot, i);
1082 
1083 		/*
1084 		 * Note that if npages > 0 then i must be a multiple of npages,
1085 		 * since huge pages are only used to back the guest at guest
1086 		 * real addresses that are a multiple of their size.
1087 		 * Since we have at most one PTE covering any given guest
1088 		 * real address, if npages > 1 we can skip to i + npages.
1089 		 */
1090 		j = i + 1;
1091 		if (npages) {
1092 			set_dirty_bits(map, i, npages);
1093 			j = i + npages;
1094 		}
1095 	}
1096 	return 0;
1097 }
1098 
1099 void kvmppc_radix_flush_memslot(struct kvm *kvm,
1100 				const struct kvm_memory_slot *memslot)
1101 {
1102 	unsigned long n;
1103 	pte_t *ptep;
1104 	unsigned long gpa;
1105 	unsigned int shift;
1106 
1107 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)
1108 		kvmppc_uvmem_drop_pages(memslot, kvm, true);
1109 
1110 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1111 		return;
1112 
1113 	gpa = memslot->base_gfn << PAGE_SHIFT;
1114 	spin_lock(&kvm->mmu_lock);
1115 	for (n = memslot->npages; n; --n) {
1116 		ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
1117 		if (ptep && pte_present(*ptep))
1118 			kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
1119 					 kvm->arch.lpid);
1120 		gpa += PAGE_SIZE;
1121 	}
1122 	spin_unlock(&kvm->mmu_lock);
1123 }
1124 
1125 static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info,
1126 				 int psize, int *indexp)
1127 {
1128 	if (!mmu_psize_defs[psize].shift)
1129 		return;
1130 	info->ap_encodings[*indexp] = mmu_psize_defs[psize].shift |
1131 		(mmu_psize_defs[psize].ap << 29);
1132 	++(*indexp);
1133 }
1134 
1135 int kvmhv_get_rmmu_info(struct kvm *kvm, struct kvm_ppc_rmmu_info *info)
1136 {
1137 	int i;
1138 
1139 	if (!radix_enabled())
1140 		return -EINVAL;
1141 	memset(info, 0, sizeof(*info));
1142 
1143 	/* 4k page size */
1144 	info->geometries[0].page_shift = 12;
1145 	info->geometries[0].level_bits[0] = 9;
1146 	for (i = 1; i < 4; ++i)
1147 		info->geometries[0].level_bits[i] = p9_supported_radix_bits[i];
1148 	/* 64k page size */
1149 	info->geometries[1].page_shift = 16;
1150 	for (i = 0; i < 4; ++i)
1151 		info->geometries[1].level_bits[i] = p9_supported_radix_bits[i];
1152 
1153 	i = 0;
1154 	add_rmmu_ap_encoding(info, MMU_PAGE_4K, &i);
1155 	add_rmmu_ap_encoding(info, MMU_PAGE_64K, &i);
1156 	add_rmmu_ap_encoding(info, MMU_PAGE_2M, &i);
1157 	add_rmmu_ap_encoding(info, MMU_PAGE_1G, &i);
1158 
1159 	return 0;
1160 }
1161 
1162 int kvmppc_init_vm_radix(struct kvm *kvm)
1163 {
1164 	kvm->arch.pgtable = pgd_alloc(kvm->mm);
1165 	if (!kvm->arch.pgtable)
1166 		return -ENOMEM;
1167 	return 0;
1168 }
1169 
1170 static void pte_ctor(void *addr)
1171 {
1172 	memset(addr, 0, RADIX_PTE_TABLE_SIZE);
1173 }
1174 
1175 static void pmd_ctor(void *addr)
1176 {
1177 	memset(addr, 0, RADIX_PMD_TABLE_SIZE);
1178 }
1179 
1180 struct debugfs_radix_state {
1181 	struct kvm	*kvm;
1182 	struct mutex	mutex;
1183 	unsigned long	gpa;
1184 	int		lpid;
1185 	int		chars_left;
1186 	int		buf_index;
1187 	char		buf[128];
1188 	u8		hdr;
1189 };
1190 
1191 static int debugfs_radix_open(struct inode *inode, struct file *file)
1192 {
1193 	struct kvm *kvm = inode->i_private;
1194 	struct debugfs_radix_state *p;
1195 
1196 	p = kzalloc(sizeof(*p), GFP_KERNEL);
1197 	if (!p)
1198 		return -ENOMEM;
1199 
1200 	kvm_get_kvm(kvm);
1201 	p->kvm = kvm;
1202 	mutex_init(&p->mutex);
1203 	file->private_data = p;
1204 
1205 	return nonseekable_open(inode, file);
1206 }
1207 
1208 static int debugfs_radix_release(struct inode *inode, struct file *file)
1209 {
1210 	struct debugfs_radix_state *p = file->private_data;
1211 
1212 	kvm_put_kvm(p->kvm);
1213 	kfree(p);
1214 	return 0;
1215 }
1216 
1217 static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
1218 				 size_t len, loff_t *ppos)
1219 {
1220 	struct debugfs_radix_state *p = file->private_data;
1221 	ssize_t ret, r;
1222 	unsigned long n;
1223 	struct kvm *kvm;
1224 	unsigned long gpa;
1225 	pgd_t *pgt;
1226 	struct kvm_nested_guest *nested;
1227 	pgd_t *pgdp;
1228 	p4d_t p4d, *p4dp;
1229 	pud_t pud, *pudp;
1230 	pmd_t pmd, *pmdp;
1231 	pte_t *ptep;
1232 	int shift;
1233 	unsigned long pte;
1234 
1235 	kvm = p->kvm;
1236 	if (!kvm_is_radix(kvm))
1237 		return 0;
1238 
1239 	ret = mutex_lock_interruptible(&p->mutex);
1240 	if (ret)
1241 		return ret;
1242 
1243 	if (p->chars_left) {
1244 		n = p->chars_left;
1245 		if (n > len)
1246 			n = len;
1247 		r = copy_to_user(buf, p->buf + p->buf_index, n);
1248 		n -= r;
1249 		p->chars_left -= n;
1250 		p->buf_index += n;
1251 		buf += n;
1252 		len -= n;
1253 		ret = n;
1254 		if (r) {
1255 			if (!n)
1256 				ret = -EFAULT;
1257 			goto out;
1258 		}
1259 	}
1260 
1261 	gpa = p->gpa;
1262 	nested = NULL;
1263 	pgt = NULL;
1264 	while (len != 0 && p->lpid >= 0) {
1265 		if (gpa >= RADIX_PGTABLE_RANGE) {
1266 			gpa = 0;
1267 			pgt = NULL;
1268 			if (nested) {
1269 				kvmhv_put_nested(nested);
1270 				nested = NULL;
1271 			}
1272 			p->lpid = kvmhv_nested_next_lpid(kvm, p->lpid);
1273 			p->hdr = 0;
1274 			if (p->lpid < 0)
1275 				break;
1276 		}
1277 		if (!pgt) {
1278 			if (p->lpid == 0) {
1279 				pgt = kvm->arch.pgtable;
1280 			} else {
1281 				nested = kvmhv_get_nested(kvm, p->lpid, false);
1282 				if (!nested) {
1283 					gpa = RADIX_PGTABLE_RANGE;
1284 					continue;
1285 				}
1286 				pgt = nested->shadow_pgtable;
1287 			}
1288 		}
1289 		n = 0;
1290 		if (!p->hdr) {
1291 			if (p->lpid > 0)
1292 				n = scnprintf(p->buf, sizeof(p->buf),
1293 					      "\nNested LPID %d: ", p->lpid);
1294 			n += scnprintf(p->buf + n, sizeof(p->buf) - n,
1295 				      "pgdir: %lx\n", (unsigned long)pgt);
1296 			p->hdr = 1;
1297 			goto copy;
1298 		}
1299 
1300 		pgdp = pgt + pgd_index(gpa);
1301 		p4dp = p4d_offset(pgdp, gpa);
1302 		p4d = READ_ONCE(*p4dp);
1303 		if (!(p4d_val(p4d) & _PAGE_PRESENT)) {
1304 			gpa = (gpa & P4D_MASK) + P4D_SIZE;
1305 			continue;
1306 		}
1307 
1308 		pudp = pud_offset(&p4d, gpa);
1309 		pud = READ_ONCE(*pudp);
1310 		if (!(pud_val(pud) & _PAGE_PRESENT)) {
1311 			gpa = (gpa & PUD_MASK) + PUD_SIZE;
1312 			continue;
1313 		}
1314 		if (pud_val(pud) & _PAGE_PTE) {
1315 			pte = pud_val(pud);
1316 			shift = PUD_SHIFT;
1317 			goto leaf;
1318 		}
1319 
1320 		pmdp = pmd_offset(&pud, gpa);
1321 		pmd = READ_ONCE(*pmdp);
1322 		if (!(pmd_val(pmd) & _PAGE_PRESENT)) {
1323 			gpa = (gpa & PMD_MASK) + PMD_SIZE;
1324 			continue;
1325 		}
1326 		if (pmd_val(pmd) & _PAGE_PTE) {
1327 			pte = pmd_val(pmd);
1328 			shift = PMD_SHIFT;
1329 			goto leaf;
1330 		}
1331 
1332 		ptep = pte_offset_kernel(&pmd, gpa);
1333 		pte = pte_val(READ_ONCE(*ptep));
1334 		if (!(pte & _PAGE_PRESENT)) {
1335 			gpa += PAGE_SIZE;
1336 			continue;
1337 		}
1338 		shift = PAGE_SHIFT;
1339 	leaf:
1340 		n = scnprintf(p->buf, sizeof(p->buf),
1341 			      " %lx: %lx %d\n", gpa, pte, shift);
1342 		gpa += 1ul << shift;
1343 	copy:
1344 		p->chars_left = n;
1345 		if (n > len)
1346 			n = len;
1347 		r = copy_to_user(buf, p->buf, n);
1348 		n -= r;
1349 		p->chars_left -= n;
1350 		p->buf_index = n;
1351 		buf += n;
1352 		len -= n;
1353 		ret += n;
1354 		if (r) {
1355 			if (!ret)
1356 				ret = -EFAULT;
1357 			break;
1358 		}
1359 	}
1360 	p->gpa = gpa;
1361 	if (nested)
1362 		kvmhv_put_nested(nested);
1363 
1364  out:
1365 	mutex_unlock(&p->mutex);
1366 	return ret;
1367 }
1368 
1369 static ssize_t debugfs_radix_write(struct file *file, const char __user *buf,
1370 			   size_t len, loff_t *ppos)
1371 {
1372 	return -EACCES;
1373 }
1374 
1375 static const struct file_operations debugfs_radix_fops = {
1376 	.owner	 = THIS_MODULE,
1377 	.open	 = debugfs_radix_open,
1378 	.release = debugfs_radix_release,
1379 	.read	 = debugfs_radix_read,
1380 	.write	 = debugfs_radix_write,
1381 	.llseek	 = generic_file_llseek,
1382 };
1383 
1384 void kvmhv_radix_debugfs_init(struct kvm *kvm)
1385 {
1386 	debugfs_create_file("radix", 0400, kvm->arch.debugfs_dir, kvm,
1387 			    &debugfs_radix_fops);
1388 }
1389 
1390 int kvmppc_radix_init(void)
1391 {
1392 	unsigned long size = sizeof(void *) << RADIX_PTE_INDEX_SIZE;
1393 
1394 	kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, 0, pte_ctor);
1395 	if (!kvm_pte_cache)
1396 		return -ENOMEM;
1397 
1398 	size = sizeof(void *) << RADIX_PMD_INDEX_SIZE;
1399 
1400 	kvm_pmd_cache = kmem_cache_create("kvm-pmd", size, size, 0, pmd_ctor);
1401 	if (!kvm_pmd_cache) {
1402 		kmem_cache_destroy(kvm_pte_cache);
1403 		return -ENOMEM;
1404 	}
1405 
1406 	return 0;
1407 }
1408 
1409 void kvmppc_radix_exit(void)
1410 {
1411 	kmem_cache_destroy(kvm_pte_cache);
1412 	kmem_cache_destroy(kvm_pmd_cache);
1413 }
1414