xref: /linux/arch/powerpc/kvm/book3s_64_mmu_radix.c (revision bdd1a21b52557ea8f61d0a5dc2f77151b576eb70)
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 #include <linux/pgtable.h>
15 
16 #include <asm/kvm_ppc.h>
17 #include <asm/kvm_book3s.h>
18 #include <asm/page.h>
19 #include <asm/mmu.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 #include <asm/plpar_wrappers.h>
25 
26 /*
27  * Supported radix tree geometry.
28  * Like p9, we support either 5 or 9 bits at the first (lowest) level,
29  * for a page size of 64k or 4k.
30  */
31 static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
32 
33 unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
34 					      gva_t eaddr, void *to, void *from,
35 					      unsigned long n)
36 {
37 	int old_pid, old_lpid;
38 	unsigned long quadrant, ret = n;
39 	bool is_load = !!to;
40 
41 	/* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */
42 	if (kvmhv_on_pseries())
43 		return plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr,
44 					  (to != NULL) ? __pa(to): 0,
45 					  (from != NULL) ? __pa(from): 0, n);
46 
47 	quadrant = 1;
48 	if (!pid)
49 		quadrant = 2;
50 	if (is_load)
51 		from = (void *) (eaddr | (quadrant << 62));
52 	else
53 		to = (void *) (eaddr | (quadrant << 62));
54 
55 	preempt_disable();
56 
57 	/* switch the lpid first to avoid running host with unallocated pid */
58 	old_lpid = mfspr(SPRN_LPID);
59 	if (old_lpid != lpid)
60 		mtspr(SPRN_LPID, lpid);
61 	if (quadrant == 1) {
62 		old_pid = mfspr(SPRN_PID);
63 		if (old_pid != pid)
64 			mtspr(SPRN_PID, pid);
65 	}
66 	isync();
67 
68 	if (is_load)
69 		ret = copy_from_user_nofault(to, (const void __user *)from, n);
70 	else
71 		ret = copy_to_user_nofault((void __user *)to, from, n);
72 
73 	/* switch the pid first to avoid running host with unallocated pid */
74 	if (quadrant == 1 && pid != old_pid)
75 		mtspr(SPRN_PID, old_pid);
76 	if (lpid != old_lpid)
77 		mtspr(SPRN_LPID, old_lpid);
78 	isync();
79 
80 	preempt_enable();
81 
82 	return ret;
83 }
84 EXPORT_SYMBOL_GPL(__kvmhv_copy_tofrom_guest_radix);
85 
86 static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
87 					  void *to, void *from, unsigned long n)
88 {
89 	int lpid = vcpu->kvm->arch.lpid;
90 	int pid = vcpu->arch.pid;
91 
92 	/* This would cause a data segment intr so don't allow the access */
93 	if (eaddr & (0x3FFUL << 52))
94 		return -EINVAL;
95 
96 	/* Should we be using the nested lpid */
97 	if (vcpu->arch.nested)
98 		lpid = vcpu->arch.nested->shadow_lpid;
99 
100 	/* If accessing quadrant 3 then pid is expected to be 0 */
101 	if (((eaddr >> 62) & 0x3) == 0x3)
102 		pid = 0;
103 
104 	eaddr &= ~(0xFFFUL << 52);
105 
106 	return __kvmhv_copy_tofrom_guest_radix(lpid, pid, eaddr, to, from, n);
107 }
108 
109 long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to,
110 				 unsigned long n)
111 {
112 	long ret;
113 
114 	ret = kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, to, NULL, n);
115 	if (ret > 0)
116 		memset(to + (n - ret), 0, ret);
117 
118 	return ret;
119 }
120 EXPORT_SYMBOL_GPL(kvmhv_copy_from_guest_radix);
121 
122 long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *from,
123 			       unsigned long n)
124 {
125 	return kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, NULL, from, n);
126 }
127 EXPORT_SYMBOL_GPL(kvmhv_copy_to_guest_radix);
128 
129 int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr,
130 			       struct kvmppc_pte *gpte, u64 root,
131 			       u64 *pte_ret_p)
132 {
133 	struct kvm *kvm = vcpu->kvm;
134 	int ret, level, ps;
135 	unsigned long rts, bits, offset, index;
136 	u64 pte, base, gpa;
137 	__be64 rpte;
138 
139 	rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
140 		((root & RTS2_MASK) >> RTS2_SHIFT);
141 	bits = root & RPDS_MASK;
142 	base = root & RPDB_MASK;
143 
144 	offset = rts + 31;
145 
146 	/* Current implementations only support 52-bit space */
147 	if (offset != 52)
148 		return -EINVAL;
149 
150 	/* Walk each level of the radix tree */
151 	for (level = 3; level >= 0; --level) {
152 		u64 addr;
153 		/* Check a valid size */
154 		if (level && bits != p9_supported_radix_bits[level])
155 			return -EINVAL;
156 		if (level == 0 && !(bits == 5 || bits == 9))
157 			return -EINVAL;
158 		offset -= bits;
159 		index = (eaddr >> offset) & ((1UL << bits) - 1);
160 		/* Check that low bits of page table base are zero */
161 		if (base & ((1UL << (bits + 3)) - 1))
162 			return -EINVAL;
163 		/* Read the entry from guest memory */
164 		addr = base + (index * sizeof(rpte));
165 		vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
166 		ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte));
167 		srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
168 		if (ret) {
169 			if (pte_ret_p)
170 				*pte_ret_p = addr;
171 			return ret;
172 		}
173 		pte = __be64_to_cpu(rpte);
174 		if (!(pte & _PAGE_PRESENT))
175 			return -ENOENT;
176 		/* Check if a leaf entry */
177 		if (pte & _PAGE_PTE)
178 			break;
179 		/* Get ready to walk the next level */
180 		base = pte & RPDB_MASK;
181 		bits = pte & RPDS_MASK;
182 	}
183 
184 	/* Need a leaf at lowest level; 512GB pages not supported */
185 	if (level < 0 || level == 3)
186 		return -EINVAL;
187 
188 	/* We found a valid leaf PTE */
189 	/* Offset is now log base 2 of the page size */
190 	gpa = pte & 0x01fffffffffff000ul;
191 	if (gpa & ((1ul << offset) - 1))
192 		return -EINVAL;
193 	gpa |= eaddr & ((1ul << offset) - 1);
194 	for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps)
195 		if (offset == mmu_psize_defs[ps].shift)
196 			break;
197 	gpte->page_size = ps;
198 	gpte->page_shift = offset;
199 
200 	gpte->eaddr = eaddr;
201 	gpte->raddr = gpa;
202 
203 	/* Work out permissions */
204 	gpte->may_read = !!(pte & _PAGE_READ);
205 	gpte->may_write = !!(pte & _PAGE_WRITE);
206 	gpte->may_execute = !!(pte & _PAGE_EXEC);
207 
208 	gpte->rc = pte & (_PAGE_ACCESSED | _PAGE_DIRTY);
209 
210 	if (pte_ret_p)
211 		*pte_ret_p = pte;
212 
213 	return 0;
214 }
215 
216 /*
217  * Used to walk a partition or process table radix tree in guest memory
218  * Note: We exploit the fact that a partition table and a process
219  * table have the same layout, a partition-scoped page table and a
220  * process-scoped page table have the same layout, and the 2nd
221  * doubleword of a partition table entry has the same layout as
222  * the PTCR register.
223  */
224 int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
225 				     struct kvmppc_pte *gpte, u64 table,
226 				     int table_index, u64 *pte_ret_p)
227 {
228 	struct kvm *kvm = vcpu->kvm;
229 	int ret;
230 	unsigned long size, ptbl, root;
231 	struct prtb_entry entry;
232 
233 	if ((table & PRTS_MASK) > 24)
234 		return -EINVAL;
235 	size = 1ul << ((table & PRTS_MASK) + 12);
236 
237 	/* Is the table big enough to contain this entry? */
238 	if ((table_index * sizeof(entry)) >= size)
239 		return -EINVAL;
240 
241 	/* Read the table to find the root of the radix tree */
242 	ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry));
243 	vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
244 	ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry));
245 	srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
246 	if (ret)
247 		return ret;
248 
249 	/* Root is stored in the first double word */
250 	root = be64_to_cpu(entry.prtb0);
251 
252 	return kvmppc_mmu_walk_radix_tree(vcpu, eaddr, gpte, root, pte_ret_p);
253 }
254 
255 int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
256 			   struct kvmppc_pte *gpte, bool data, bool iswrite)
257 {
258 	u32 pid;
259 	u64 pte;
260 	int ret;
261 
262 	/* Work out effective PID */
263 	switch (eaddr >> 62) {
264 	case 0:
265 		pid = vcpu->arch.pid;
266 		break;
267 	case 3:
268 		pid = 0;
269 		break;
270 	default:
271 		return -EINVAL;
272 	}
273 
274 	ret = kvmppc_mmu_radix_translate_table(vcpu, eaddr, gpte,
275 				vcpu->kvm->arch.process_table, pid, &pte);
276 	if (ret)
277 		return ret;
278 
279 	/* Check privilege (applies only to process scoped translations) */
280 	if (kvmppc_get_msr(vcpu) & MSR_PR) {
281 		if (pte & _PAGE_PRIVILEGED) {
282 			gpte->may_read = 0;
283 			gpte->may_write = 0;
284 			gpte->may_execute = 0;
285 		}
286 	} else {
287 		if (!(pte & _PAGE_PRIVILEGED)) {
288 			/* Check AMR/IAMR to see if strict mode is in force */
289 			if (vcpu->arch.amr & (1ul << 62))
290 				gpte->may_read = 0;
291 			if (vcpu->arch.amr & (1ul << 63))
292 				gpte->may_write = 0;
293 			if (vcpu->arch.iamr & (1ul << 62))
294 				gpte->may_execute = 0;
295 		}
296 	}
297 
298 	return 0;
299 }
300 
301 void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
302 			     unsigned int pshift, unsigned int lpid)
303 {
304 	unsigned long psize = PAGE_SIZE;
305 	int psi;
306 	long rc;
307 	unsigned long rb;
308 
309 	if (pshift)
310 		psize = 1UL << pshift;
311 	else
312 		pshift = PAGE_SHIFT;
313 
314 	addr &= ~(psize - 1);
315 
316 	if (!kvmhv_on_pseries()) {
317 		radix__flush_tlb_lpid_page(lpid, addr, psize);
318 		return;
319 	}
320 
321 	psi = shift_to_mmu_psize(pshift);
322 
323 	if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE)) {
324 		rb = addr | (mmu_get_ap(psi) << PPC_BITLSHIFT(58));
325 		rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(0, 0, 1),
326 					lpid, rb);
327 	} else {
328 		rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
329 					    H_RPTI_TYPE_NESTED |
330 					    H_RPTI_TYPE_TLB,
331 					    psize_to_rpti_pgsize(psi),
332 					    addr, addr + psize);
333 	}
334 
335 	if (rc)
336 		pr_err("KVM: TLB page invalidation hcall failed, rc=%ld\n", rc);
337 }
338 
339 static void kvmppc_radix_flush_pwc(struct kvm *kvm, unsigned int lpid)
340 {
341 	long rc;
342 
343 	if (!kvmhv_on_pseries()) {
344 		radix__flush_pwc_lpid(lpid);
345 		return;
346 	}
347 
348 	if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE))
349 		rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(1, 0, 1),
350 					lpid, TLBIEL_INVAL_SET_LPID);
351 	else
352 		rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
353 					    H_RPTI_TYPE_NESTED |
354 					    H_RPTI_TYPE_PWC, H_RPTI_PAGE_ALL,
355 					    0, -1UL);
356 	if (rc)
357 		pr_err("KVM: TLB PWC invalidation hcall failed, rc=%ld\n", rc);
358 }
359 
360 static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep,
361 				      unsigned long clr, unsigned long set,
362 				      unsigned long addr, unsigned int shift)
363 {
364 	return __radix_pte_update(ptep, clr, set);
365 }
366 
367 static void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr,
368 			     pte_t *ptep, pte_t pte)
369 {
370 	radix__set_pte_at(kvm->mm, addr, ptep, pte, 0);
371 }
372 
373 static struct kmem_cache *kvm_pte_cache;
374 static struct kmem_cache *kvm_pmd_cache;
375 
376 static pte_t *kvmppc_pte_alloc(void)
377 {
378 	pte_t *pte;
379 
380 	pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL);
381 	/* pmd_populate() will only reference _pa(pte). */
382 	kmemleak_ignore(pte);
383 
384 	return pte;
385 }
386 
387 static void kvmppc_pte_free(pte_t *ptep)
388 {
389 	kmem_cache_free(kvm_pte_cache, ptep);
390 }
391 
392 static pmd_t *kvmppc_pmd_alloc(void)
393 {
394 	pmd_t *pmd;
395 
396 	pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL);
397 	/* pud_populate() will only reference _pa(pmd). */
398 	kmemleak_ignore(pmd);
399 
400 	return pmd;
401 }
402 
403 static void kvmppc_pmd_free(pmd_t *pmdp)
404 {
405 	kmem_cache_free(kvm_pmd_cache, pmdp);
406 }
407 
408 /* Called with kvm->mmu_lock held */
409 void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, unsigned long gpa,
410 		      unsigned int shift,
411 		      const struct kvm_memory_slot *memslot,
412 		      unsigned int lpid)
413 
414 {
415 	unsigned long old;
416 	unsigned long gfn = gpa >> PAGE_SHIFT;
417 	unsigned long page_size = PAGE_SIZE;
418 	unsigned long hpa;
419 
420 	old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift);
421 	kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
422 
423 	/* The following only applies to L1 entries */
424 	if (lpid != kvm->arch.lpid)
425 		return;
426 
427 	if (!memslot) {
428 		memslot = gfn_to_memslot(kvm, gfn);
429 		if (!memslot)
430 			return;
431 	}
432 	if (shift) { /* 1GB or 2MB page */
433 		page_size = 1ul << shift;
434 		if (shift == PMD_SHIFT)
435 			kvm->stat.num_2M_pages--;
436 		else if (shift == PUD_SHIFT)
437 			kvm->stat.num_1G_pages--;
438 	}
439 
440 	gpa &= ~(page_size - 1);
441 	hpa = old & PTE_RPN_MASK;
442 	kvmhv_remove_nest_rmap_range(kvm, memslot, gpa, hpa, page_size);
443 
444 	if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap)
445 		kvmppc_update_dirty_map(memslot, gfn, page_size);
446 }
447 
448 /*
449  * kvmppc_free_p?d are used to free existing page tables, and recursively
450  * descend and clear and free children.
451  * Callers are responsible for flushing the PWC.
452  *
453  * When page tables are being unmapped/freed as part of page fault path
454  * (full == false), valid ptes are generally not expected; however, there
455  * is one situation where they arise, which is when dirty page logging is
456  * turned off for a memslot while the VM is running.  The new memslot
457  * becomes visible to page faults before the memslot commit function
458  * gets to flush the memslot, which can lead to a 2MB page mapping being
459  * installed for a guest physical address where there are already 64kB
460  * (or 4kB) mappings (of sub-pages of the same 2MB page).
461  */
462 static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full,
463 				  unsigned int lpid)
464 {
465 	if (full) {
466 		memset(pte, 0, sizeof(long) << RADIX_PTE_INDEX_SIZE);
467 	} else {
468 		pte_t *p = pte;
469 		unsigned long it;
470 
471 		for (it = 0; it < PTRS_PER_PTE; ++it, ++p) {
472 			if (pte_val(*p) == 0)
473 				continue;
474 			kvmppc_unmap_pte(kvm, p,
475 					 pte_pfn(*p) << PAGE_SHIFT,
476 					 PAGE_SHIFT, NULL, lpid);
477 		}
478 	}
479 
480 	kvmppc_pte_free(pte);
481 }
482 
483 static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
484 				  unsigned int lpid)
485 {
486 	unsigned long im;
487 	pmd_t *p = pmd;
488 
489 	for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
490 		if (!pmd_present(*p))
491 			continue;
492 		if (pmd_is_leaf(*p)) {
493 			if (full) {
494 				pmd_clear(p);
495 			} else {
496 				WARN_ON_ONCE(1);
497 				kvmppc_unmap_pte(kvm, (pte_t *)p,
498 					 pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
499 					 PMD_SHIFT, NULL, lpid);
500 			}
501 		} else {
502 			pte_t *pte;
503 
504 			pte = pte_offset_map(p, 0);
505 			kvmppc_unmap_free_pte(kvm, pte, full, lpid);
506 			pmd_clear(p);
507 		}
508 	}
509 	kvmppc_pmd_free(pmd);
510 }
511 
512 static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud,
513 				  unsigned int lpid)
514 {
515 	unsigned long iu;
516 	pud_t *p = pud;
517 
518 	for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) {
519 		if (!pud_present(*p))
520 			continue;
521 		if (pud_is_leaf(*p)) {
522 			pud_clear(p);
523 		} else {
524 			pmd_t *pmd;
525 
526 			pmd = pmd_offset(p, 0);
527 			kvmppc_unmap_free_pmd(kvm, pmd, true, lpid);
528 			pud_clear(p);
529 		}
530 	}
531 	pud_free(kvm->mm, pud);
532 }
533 
534 void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, unsigned int lpid)
535 {
536 	unsigned long ig;
537 
538 	for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
539 		p4d_t *p4d = p4d_offset(pgd, 0);
540 		pud_t *pud;
541 
542 		if (!p4d_present(*p4d))
543 			continue;
544 		pud = pud_offset(p4d, 0);
545 		kvmppc_unmap_free_pud(kvm, pud, lpid);
546 		p4d_clear(p4d);
547 	}
548 }
549 
550 void kvmppc_free_radix(struct kvm *kvm)
551 {
552 	if (kvm->arch.pgtable) {
553 		kvmppc_free_pgtable_radix(kvm, kvm->arch.pgtable,
554 					  kvm->arch.lpid);
555 		pgd_free(kvm->mm, kvm->arch.pgtable);
556 		kvm->arch.pgtable = NULL;
557 	}
558 }
559 
560 static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd,
561 					unsigned long gpa, unsigned int lpid)
562 {
563 	pte_t *pte = pte_offset_kernel(pmd, 0);
564 
565 	/*
566 	 * Clearing the pmd entry then flushing the PWC ensures that the pte
567 	 * page no longer be cached by the MMU, so can be freed without
568 	 * flushing the PWC again.
569 	 */
570 	pmd_clear(pmd);
571 	kvmppc_radix_flush_pwc(kvm, lpid);
572 
573 	kvmppc_unmap_free_pte(kvm, pte, false, lpid);
574 }
575 
576 static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
577 					unsigned long gpa, unsigned int lpid)
578 {
579 	pmd_t *pmd = pmd_offset(pud, 0);
580 
581 	/*
582 	 * Clearing the pud entry then flushing the PWC ensures that the pmd
583 	 * page and any children pte pages will no longer be cached by the MMU,
584 	 * so can be freed without flushing the PWC again.
585 	 */
586 	pud_clear(pud);
587 	kvmppc_radix_flush_pwc(kvm, lpid);
588 
589 	kvmppc_unmap_free_pmd(kvm, pmd, false, lpid);
590 }
591 
592 /*
593  * There are a number of bits which may differ between different faults to
594  * the same partition scope entry. RC bits, in the course of cleaning and
595  * aging. And the write bit can change, either the access could have been
596  * upgraded, or a read fault could happen concurrently with a write fault
597  * that sets those bits first.
598  */
599 #define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED))
600 
601 int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
602 		      unsigned long gpa, unsigned int level,
603 		      unsigned long mmu_seq, unsigned int lpid,
604 		      unsigned long *rmapp, struct rmap_nested **n_rmap)
605 {
606 	pgd_t *pgd;
607 	p4d_t *p4d;
608 	pud_t *pud, *new_pud = NULL;
609 	pmd_t *pmd, *new_pmd = NULL;
610 	pte_t *ptep, *new_ptep = NULL;
611 	int ret;
612 
613 	/* Traverse the guest's 2nd-level tree, allocate new levels needed */
614 	pgd = pgtable + pgd_index(gpa);
615 	p4d = p4d_offset(pgd, gpa);
616 
617 	pud = NULL;
618 	if (p4d_present(*p4d))
619 		pud = pud_offset(p4d, gpa);
620 	else
621 		new_pud = pud_alloc_one(kvm->mm, gpa);
622 
623 	pmd = NULL;
624 	if (pud && pud_present(*pud) && !pud_is_leaf(*pud))
625 		pmd = pmd_offset(pud, gpa);
626 	else if (level <= 1)
627 		new_pmd = kvmppc_pmd_alloc();
628 
629 	if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
630 		new_ptep = kvmppc_pte_alloc();
631 
632 	/* Check if we might have been invalidated; let the guest retry if so */
633 	spin_lock(&kvm->mmu_lock);
634 	ret = -EAGAIN;
635 	if (mmu_notifier_retry(kvm, mmu_seq))
636 		goto out_unlock;
637 
638 	/* Now traverse again under the lock and change the tree */
639 	ret = -ENOMEM;
640 	if (p4d_none(*p4d)) {
641 		if (!new_pud)
642 			goto out_unlock;
643 		p4d_populate(kvm->mm, p4d, new_pud);
644 		new_pud = NULL;
645 	}
646 	pud = pud_offset(p4d, gpa);
647 	if (pud_is_leaf(*pud)) {
648 		unsigned long hgpa = gpa & PUD_MASK;
649 
650 		/* Check if we raced and someone else has set the same thing */
651 		if (level == 2) {
652 			if (pud_raw(*pud) == pte_raw(pte)) {
653 				ret = 0;
654 				goto out_unlock;
655 			}
656 			/* Valid 1GB page here already, add our extra bits */
657 			WARN_ON_ONCE((pud_val(*pud) ^ pte_val(pte)) &
658 							PTE_BITS_MUST_MATCH);
659 			kvmppc_radix_update_pte(kvm, (pte_t *)pud,
660 					      0, pte_val(pte), hgpa, PUD_SHIFT);
661 			ret = 0;
662 			goto out_unlock;
663 		}
664 		/*
665 		 * If we raced with another CPU which has just put
666 		 * a 1GB pte in after we saw a pmd page, try again.
667 		 */
668 		if (!new_pmd) {
669 			ret = -EAGAIN;
670 			goto out_unlock;
671 		}
672 		/* Valid 1GB page here already, remove it */
673 		kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL,
674 				 lpid);
675 	}
676 	if (level == 2) {
677 		if (!pud_none(*pud)) {
678 			/*
679 			 * There's a page table page here, but we wanted to
680 			 * install a large page, so remove and free the page
681 			 * table page.
682 			 */
683 			kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa, lpid);
684 		}
685 		kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte);
686 		if (rmapp && n_rmap)
687 			kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
688 		ret = 0;
689 		goto out_unlock;
690 	}
691 	if (pud_none(*pud)) {
692 		if (!new_pmd)
693 			goto out_unlock;
694 		pud_populate(kvm->mm, pud, new_pmd);
695 		new_pmd = NULL;
696 	}
697 	pmd = pmd_offset(pud, gpa);
698 	if (pmd_is_leaf(*pmd)) {
699 		unsigned long lgpa = gpa & PMD_MASK;
700 
701 		/* Check if we raced and someone else has set the same thing */
702 		if (level == 1) {
703 			if (pmd_raw(*pmd) == pte_raw(pte)) {
704 				ret = 0;
705 				goto out_unlock;
706 			}
707 			/* Valid 2MB page here already, add our extra bits */
708 			WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) &
709 							PTE_BITS_MUST_MATCH);
710 			kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd),
711 					0, pte_val(pte), lgpa, PMD_SHIFT);
712 			ret = 0;
713 			goto out_unlock;
714 		}
715 
716 		/*
717 		 * If we raced with another CPU which has just put
718 		 * a 2MB pte in after we saw a pte page, try again.
719 		 */
720 		if (!new_ptep) {
721 			ret = -EAGAIN;
722 			goto out_unlock;
723 		}
724 		/* Valid 2MB page here already, remove it */
725 		kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL,
726 				 lpid);
727 	}
728 	if (level == 1) {
729 		if (!pmd_none(*pmd)) {
730 			/*
731 			 * There's a page table page here, but we wanted to
732 			 * install a large page, so remove and free the page
733 			 * table page.
734 			 */
735 			kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa, lpid);
736 		}
737 		kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
738 		if (rmapp && n_rmap)
739 			kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
740 		ret = 0;
741 		goto out_unlock;
742 	}
743 	if (pmd_none(*pmd)) {
744 		if (!new_ptep)
745 			goto out_unlock;
746 		pmd_populate(kvm->mm, pmd, new_ptep);
747 		new_ptep = NULL;
748 	}
749 	ptep = pte_offset_kernel(pmd, gpa);
750 	if (pte_present(*ptep)) {
751 		/* Check if someone else set the same thing */
752 		if (pte_raw(*ptep) == pte_raw(pte)) {
753 			ret = 0;
754 			goto out_unlock;
755 		}
756 		/* Valid page here already, add our extra bits */
757 		WARN_ON_ONCE((pte_val(*ptep) ^ pte_val(pte)) &
758 							PTE_BITS_MUST_MATCH);
759 		kvmppc_radix_update_pte(kvm, ptep, 0, pte_val(pte), gpa, 0);
760 		ret = 0;
761 		goto out_unlock;
762 	}
763 	kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte);
764 	if (rmapp && n_rmap)
765 		kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
766 	ret = 0;
767 
768  out_unlock:
769 	spin_unlock(&kvm->mmu_lock);
770 	if (new_pud)
771 		pud_free(kvm->mm, new_pud);
772 	if (new_pmd)
773 		kvmppc_pmd_free(new_pmd);
774 	if (new_ptep)
775 		kvmppc_pte_free(new_ptep);
776 	return ret;
777 }
778 
779 bool kvmppc_hv_handle_set_rc(struct kvm *kvm, bool nested, bool writing,
780 			     unsigned long gpa, unsigned int lpid)
781 {
782 	unsigned long pgflags;
783 	unsigned int shift;
784 	pte_t *ptep;
785 
786 	/*
787 	 * Need to set an R or C bit in the 2nd-level tables;
788 	 * since we are just helping out the hardware here,
789 	 * it is sufficient to do what the hardware does.
790 	 */
791 	pgflags = _PAGE_ACCESSED;
792 	if (writing)
793 		pgflags |= _PAGE_DIRTY;
794 
795 	if (nested)
796 		ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
797 	else
798 		ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
799 
800 	if (ptep && pte_present(*ptep) && (!writing || pte_write(*ptep))) {
801 		kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, gpa, shift);
802 		return true;
803 	}
804 	return false;
805 }
806 
807 int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
808 				   unsigned long gpa,
809 				   struct kvm_memory_slot *memslot,
810 				   bool writing, bool kvm_ro,
811 				   pte_t *inserted_pte, unsigned int *levelp)
812 {
813 	struct kvm *kvm = vcpu->kvm;
814 	struct page *page = NULL;
815 	unsigned long mmu_seq;
816 	unsigned long hva, gfn = gpa >> PAGE_SHIFT;
817 	bool upgrade_write = false;
818 	bool *upgrade_p = &upgrade_write;
819 	pte_t pte, *ptep;
820 	unsigned int shift, level;
821 	int ret;
822 	bool large_enable;
823 
824 	/* used to check for invalidations in progress */
825 	mmu_seq = kvm->mmu_notifier_seq;
826 	smp_rmb();
827 
828 	/*
829 	 * Do a fast check first, since __gfn_to_pfn_memslot doesn't
830 	 * do it with !atomic && !async, which is how we call it.
831 	 * We always ask for write permission since the common case
832 	 * is that the page is writable.
833 	 */
834 	hva = gfn_to_hva_memslot(memslot, gfn);
835 	if (!kvm_ro && get_user_page_fast_only(hva, FOLL_WRITE, &page)) {
836 		upgrade_write = true;
837 	} else {
838 		unsigned long pfn;
839 
840 		/* Call KVM generic code to do the slow-path check */
841 		pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL,
842 					   writing, upgrade_p, NULL);
843 		if (is_error_noslot_pfn(pfn))
844 			return -EFAULT;
845 		page = NULL;
846 		if (pfn_valid(pfn)) {
847 			page = pfn_to_page(pfn);
848 			if (PageReserved(page))
849 				page = NULL;
850 		}
851 	}
852 
853 	/*
854 	 * Read the PTE from the process' radix tree and use that
855 	 * so we get the shift and attribute bits.
856 	 */
857 	spin_lock(&kvm->mmu_lock);
858 	ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &shift);
859 	pte = __pte(0);
860 	if (ptep)
861 		pte = READ_ONCE(*ptep);
862 	spin_unlock(&kvm->mmu_lock);
863 	/*
864 	 * If the PTE disappeared temporarily due to a THP
865 	 * collapse, just return and let the guest try again.
866 	 */
867 	if (!pte_present(pte)) {
868 		if (page)
869 			put_page(page);
870 		return RESUME_GUEST;
871 	}
872 
873 	/* If we're logging dirty pages, always map single pages */
874 	large_enable = !(memslot->flags & KVM_MEM_LOG_DIRTY_PAGES);
875 
876 	/* Get pte level from shift/size */
877 	if (large_enable && shift == PUD_SHIFT &&
878 	    (gpa & (PUD_SIZE - PAGE_SIZE)) ==
879 	    (hva & (PUD_SIZE - PAGE_SIZE))) {
880 		level = 2;
881 	} else if (large_enable && shift == PMD_SHIFT &&
882 		   (gpa & (PMD_SIZE - PAGE_SIZE)) ==
883 		   (hva & (PMD_SIZE - PAGE_SIZE))) {
884 		level = 1;
885 	} else {
886 		level = 0;
887 		if (shift > PAGE_SHIFT) {
888 			/*
889 			 * If the pte maps more than one page, bring over
890 			 * bits from the virtual address to get the real
891 			 * address of the specific single page we want.
892 			 */
893 			unsigned long rpnmask = (1ul << shift) - PAGE_SIZE;
894 			pte = __pte(pte_val(pte) | (hva & rpnmask));
895 		}
896 	}
897 
898 	pte = __pte(pte_val(pte) | _PAGE_EXEC | _PAGE_ACCESSED);
899 	if (writing || upgrade_write) {
900 		if (pte_val(pte) & _PAGE_WRITE)
901 			pte = __pte(pte_val(pte) | _PAGE_DIRTY);
902 	} else {
903 		pte = __pte(pte_val(pte) & ~(_PAGE_WRITE | _PAGE_DIRTY));
904 	}
905 
906 	/* Allocate space in the tree and write the PTE */
907 	ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level,
908 				mmu_seq, kvm->arch.lpid, NULL, NULL);
909 	if (inserted_pte)
910 		*inserted_pte = pte;
911 	if (levelp)
912 		*levelp = level;
913 
914 	if (page) {
915 		if (!ret && (pte_val(pte) & _PAGE_WRITE))
916 			set_page_dirty_lock(page);
917 		put_page(page);
918 	}
919 
920 	/* Increment number of large pages if we (successfully) inserted one */
921 	if (!ret) {
922 		if (level == 1)
923 			kvm->stat.num_2M_pages++;
924 		else if (level == 2)
925 			kvm->stat.num_1G_pages++;
926 	}
927 
928 	return ret;
929 }
930 
931 int kvmppc_book3s_radix_page_fault(struct kvm_vcpu *vcpu,
932 				   unsigned long ea, unsigned long dsisr)
933 {
934 	struct kvm *kvm = vcpu->kvm;
935 	unsigned long gpa, gfn;
936 	struct kvm_memory_slot *memslot;
937 	long ret;
938 	bool writing = !!(dsisr & DSISR_ISSTORE);
939 	bool kvm_ro = false;
940 
941 	/* Check for unusual errors */
942 	if (dsisr & DSISR_UNSUPP_MMU) {
943 		pr_err("KVM: Got unsupported MMU fault\n");
944 		return -EFAULT;
945 	}
946 	if (dsisr & DSISR_BADACCESS) {
947 		/* Reflect to the guest as DSI */
948 		pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
949 		kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
950 		return RESUME_GUEST;
951 	}
952 
953 	/* Translate the logical address */
954 	gpa = vcpu->arch.fault_gpa & ~0xfffUL;
955 	gpa &= ~0xF000000000000000ul;
956 	gfn = gpa >> PAGE_SHIFT;
957 	if (!(dsisr & DSISR_PRTABLE_FAULT))
958 		gpa |= ea & 0xfff;
959 
960 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
961 		return kvmppc_send_page_to_uv(kvm, gfn);
962 
963 	/* Get the corresponding memslot */
964 	memslot = gfn_to_memslot(kvm, gfn);
965 
966 	/* No memslot means it's an emulated MMIO region */
967 	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
968 		if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
969 			     DSISR_SET_RC)) {
970 			/*
971 			 * Bad address in guest page table tree, or other
972 			 * unusual error - reflect it to the guest as DSI.
973 			 */
974 			kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
975 			return RESUME_GUEST;
976 		}
977 		return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
978 	}
979 
980 	if (memslot->flags & KVM_MEM_READONLY) {
981 		if (writing) {
982 			/* give the guest a DSI */
983 			kvmppc_core_queue_data_storage(vcpu, ea, DSISR_ISSTORE |
984 						       DSISR_PROTFAULT);
985 			return RESUME_GUEST;
986 		}
987 		kvm_ro = true;
988 	}
989 
990 	/* Failed to set the reference/change bits */
991 	if (dsisr & DSISR_SET_RC) {
992 		spin_lock(&kvm->mmu_lock);
993 		if (kvmppc_hv_handle_set_rc(kvm, false, writing,
994 					    gpa, kvm->arch.lpid))
995 			dsisr &= ~DSISR_SET_RC;
996 		spin_unlock(&kvm->mmu_lock);
997 
998 		if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
999 			       DSISR_PROTFAULT | DSISR_SET_RC)))
1000 			return RESUME_GUEST;
1001 	}
1002 
1003 	/* Try to insert a pte */
1004 	ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, writing,
1005 					     kvm_ro, NULL, NULL);
1006 
1007 	if (ret == 0 || ret == -EAGAIN)
1008 		ret = RESUME_GUEST;
1009 	return ret;
1010 }
1011 
1012 /* Called with kvm->mmu_lock held */
1013 void kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1014 		     unsigned long gfn)
1015 {
1016 	pte_t *ptep;
1017 	unsigned long gpa = gfn << PAGE_SHIFT;
1018 	unsigned int shift;
1019 
1020 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) {
1021 		uv_page_inval(kvm->arch.lpid, gpa, PAGE_SHIFT);
1022 		return;
1023 	}
1024 
1025 	ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1026 	if (ptep && pte_present(*ptep))
1027 		kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
1028 				 kvm->arch.lpid);
1029 }
1030 
1031 /* Called with kvm->mmu_lock held */
1032 bool kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1033 		   unsigned long gfn)
1034 {
1035 	pte_t *ptep;
1036 	unsigned long gpa = gfn << PAGE_SHIFT;
1037 	unsigned int shift;
1038 	bool ref = false;
1039 	unsigned long old, *rmapp;
1040 
1041 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1042 		return ref;
1043 
1044 	ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1045 	if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
1046 		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
1047 					      gpa, shift);
1048 		/* XXX need to flush tlb here? */
1049 		/* Also clear bit in ptes in shadow pgtable for nested guests */
1050 		rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1051 		kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_ACCESSED, 0,
1052 					       old & PTE_RPN_MASK,
1053 					       1UL << shift);
1054 		ref = true;
1055 	}
1056 	return ref;
1057 }
1058 
1059 /* Called with kvm->mmu_lock held */
1060 bool kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1061 			unsigned long gfn)
1062 
1063 {
1064 	pte_t *ptep;
1065 	unsigned long gpa = gfn << PAGE_SHIFT;
1066 	unsigned int shift;
1067 	bool ref = false;
1068 
1069 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1070 		return ref;
1071 
1072 	ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1073 	if (ptep && pte_present(*ptep) && pte_young(*ptep))
1074 		ref = true;
1075 	return ref;
1076 }
1077 
1078 /* Returns the number of PAGE_SIZE pages that are dirty */
1079 static int kvm_radix_test_clear_dirty(struct kvm *kvm,
1080 				struct kvm_memory_slot *memslot, int pagenum)
1081 {
1082 	unsigned long gfn = memslot->base_gfn + pagenum;
1083 	unsigned long gpa = gfn << PAGE_SHIFT;
1084 	pte_t *ptep, pte;
1085 	unsigned int shift;
1086 	int ret = 0;
1087 	unsigned long old, *rmapp;
1088 
1089 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1090 		return ret;
1091 
1092 	/*
1093 	 * For performance reasons we don't hold kvm->mmu_lock while walking the
1094 	 * partition scoped table.
1095 	 */
1096 	ptep = find_kvm_secondary_pte_unlocked(kvm, gpa, &shift);
1097 	if (!ptep)
1098 		return 0;
1099 
1100 	pte = READ_ONCE(*ptep);
1101 	if (pte_present(pte) && pte_dirty(pte)) {
1102 		spin_lock(&kvm->mmu_lock);
1103 		/*
1104 		 * Recheck the pte again
1105 		 */
1106 		if (pte_val(pte) != pte_val(*ptep)) {
1107 			/*
1108 			 * We have KVM_MEM_LOG_DIRTY_PAGES enabled. Hence we can
1109 			 * only find PAGE_SIZE pte entries here. We can continue
1110 			 * to use the pte addr returned by above page table
1111 			 * walk.
1112 			 */
1113 			if (!pte_present(*ptep) || !pte_dirty(*ptep)) {
1114 				spin_unlock(&kvm->mmu_lock);
1115 				return 0;
1116 			}
1117 		}
1118 
1119 		ret = 1;
1120 		VM_BUG_ON(shift);
1121 		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,
1122 					      gpa, shift);
1123 		kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid);
1124 		/* Also clear bit in ptes in shadow pgtable for nested guests */
1125 		rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1126 		kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_DIRTY, 0,
1127 					       old & PTE_RPN_MASK,
1128 					       1UL << shift);
1129 		spin_unlock(&kvm->mmu_lock);
1130 	}
1131 	return ret;
1132 }
1133 
1134 long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm,
1135 			struct kvm_memory_slot *memslot, unsigned long *map)
1136 {
1137 	unsigned long i, j;
1138 	int npages;
1139 
1140 	for (i = 0; i < memslot->npages; i = j) {
1141 		npages = kvm_radix_test_clear_dirty(kvm, memslot, i);
1142 
1143 		/*
1144 		 * Note that if npages > 0 then i must be a multiple of npages,
1145 		 * since huge pages are only used to back the guest at guest
1146 		 * real addresses that are a multiple of their size.
1147 		 * Since we have at most one PTE covering any given guest
1148 		 * real address, if npages > 1 we can skip to i + npages.
1149 		 */
1150 		j = i + 1;
1151 		if (npages) {
1152 			set_dirty_bits(map, i, npages);
1153 			j = i + npages;
1154 		}
1155 	}
1156 	return 0;
1157 }
1158 
1159 void kvmppc_radix_flush_memslot(struct kvm *kvm,
1160 				const struct kvm_memory_slot *memslot)
1161 {
1162 	unsigned long n;
1163 	pte_t *ptep;
1164 	unsigned long gpa;
1165 	unsigned int shift;
1166 
1167 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)
1168 		kvmppc_uvmem_drop_pages(memslot, kvm, true);
1169 
1170 	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1171 		return;
1172 
1173 	gpa = memslot->base_gfn << PAGE_SHIFT;
1174 	spin_lock(&kvm->mmu_lock);
1175 	for (n = memslot->npages; n; --n) {
1176 		ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1177 		if (ptep && pte_present(*ptep))
1178 			kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
1179 					 kvm->arch.lpid);
1180 		gpa += PAGE_SIZE;
1181 	}
1182 	/*
1183 	 * Increase the mmu notifier sequence number to prevent any page
1184 	 * fault that read the memslot earlier from writing a PTE.
1185 	 */
1186 	kvm->mmu_notifier_seq++;
1187 	spin_unlock(&kvm->mmu_lock);
1188 }
1189 
1190 static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info,
1191 				 int psize, int *indexp)
1192 {
1193 	if (!mmu_psize_defs[psize].shift)
1194 		return;
1195 	info->ap_encodings[*indexp] = mmu_psize_defs[psize].shift |
1196 		(mmu_psize_defs[psize].ap << 29);
1197 	++(*indexp);
1198 }
1199 
1200 int kvmhv_get_rmmu_info(struct kvm *kvm, struct kvm_ppc_rmmu_info *info)
1201 {
1202 	int i;
1203 
1204 	if (!radix_enabled())
1205 		return -EINVAL;
1206 	memset(info, 0, sizeof(*info));
1207 
1208 	/* 4k page size */
1209 	info->geometries[0].page_shift = 12;
1210 	info->geometries[0].level_bits[0] = 9;
1211 	for (i = 1; i < 4; ++i)
1212 		info->geometries[0].level_bits[i] = p9_supported_radix_bits[i];
1213 	/* 64k page size */
1214 	info->geometries[1].page_shift = 16;
1215 	for (i = 0; i < 4; ++i)
1216 		info->geometries[1].level_bits[i] = p9_supported_radix_bits[i];
1217 
1218 	i = 0;
1219 	add_rmmu_ap_encoding(info, MMU_PAGE_4K, &i);
1220 	add_rmmu_ap_encoding(info, MMU_PAGE_64K, &i);
1221 	add_rmmu_ap_encoding(info, MMU_PAGE_2M, &i);
1222 	add_rmmu_ap_encoding(info, MMU_PAGE_1G, &i);
1223 
1224 	return 0;
1225 }
1226 
1227 int kvmppc_init_vm_radix(struct kvm *kvm)
1228 {
1229 	kvm->arch.pgtable = pgd_alloc(kvm->mm);
1230 	if (!kvm->arch.pgtable)
1231 		return -ENOMEM;
1232 	return 0;
1233 }
1234 
1235 static void pte_ctor(void *addr)
1236 {
1237 	memset(addr, 0, RADIX_PTE_TABLE_SIZE);
1238 }
1239 
1240 static void pmd_ctor(void *addr)
1241 {
1242 	memset(addr, 0, RADIX_PMD_TABLE_SIZE);
1243 }
1244 
1245 struct debugfs_radix_state {
1246 	struct kvm	*kvm;
1247 	struct mutex	mutex;
1248 	unsigned long	gpa;
1249 	int		lpid;
1250 	int		chars_left;
1251 	int		buf_index;
1252 	char		buf[128];
1253 	u8		hdr;
1254 };
1255 
1256 static int debugfs_radix_open(struct inode *inode, struct file *file)
1257 {
1258 	struct kvm *kvm = inode->i_private;
1259 	struct debugfs_radix_state *p;
1260 
1261 	p = kzalloc(sizeof(*p), GFP_KERNEL);
1262 	if (!p)
1263 		return -ENOMEM;
1264 
1265 	kvm_get_kvm(kvm);
1266 	p->kvm = kvm;
1267 	mutex_init(&p->mutex);
1268 	file->private_data = p;
1269 
1270 	return nonseekable_open(inode, file);
1271 }
1272 
1273 static int debugfs_radix_release(struct inode *inode, struct file *file)
1274 {
1275 	struct debugfs_radix_state *p = file->private_data;
1276 
1277 	kvm_put_kvm(p->kvm);
1278 	kfree(p);
1279 	return 0;
1280 }
1281 
1282 static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
1283 				 size_t len, loff_t *ppos)
1284 {
1285 	struct debugfs_radix_state *p = file->private_data;
1286 	ssize_t ret, r;
1287 	unsigned long n;
1288 	struct kvm *kvm;
1289 	unsigned long gpa;
1290 	pgd_t *pgt;
1291 	struct kvm_nested_guest *nested;
1292 	pgd_t *pgdp;
1293 	p4d_t p4d, *p4dp;
1294 	pud_t pud, *pudp;
1295 	pmd_t pmd, *pmdp;
1296 	pte_t *ptep;
1297 	int shift;
1298 	unsigned long pte;
1299 
1300 	kvm = p->kvm;
1301 	if (!kvm_is_radix(kvm))
1302 		return 0;
1303 
1304 	ret = mutex_lock_interruptible(&p->mutex);
1305 	if (ret)
1306 		return ret;
1307 
1308 	if (p->chars_left) {
1309 		n = p->chars_left;
1310 		if (n > len)
1311 			n = len;
1312 		r = copy_to_user(buf, p->buf + p->buf_index, n);
1313 		n -= r;
1314 		p->chars_left -= n;
1315 		p->buf_index += n;
1316 		buf += n;
1317 		len -= n;
1318 		ret = n;
1319 		if (r) {
1320 			if (!n)
1321 				ret = -EFAULT;
1322 			goto out;
1323 		}
1324 	}
1325 
1326 	gpa = p->gpa;
1327 	nested = NULL;
1328 	pgt = NULL;
1329 	while (len != 0 && p->lpid >= 0) {
1330 		if (gpa >= RADIX_PGTABLE_RANGE) {
1331 			gpa = 0;
1332 			pgt = NULL;
1333 			if (nested) {
1334 				kvmhv_put_nested(nested);
1335 				nested = NULL;
1336 			}
1337 			p->lpid = kvmhv_nested_next_lpid(kvm, p->lpid);
1338 			p->hdr = 0;
1339 			if (p->lpid < 0)
1340 				break;
1341 		}
1342 		if (!pgt) {
1343 			if (p->lpid == 0) {
1344 				pgt = kvm->arch.pgtable;
1345 			} else {
1346 				nested = kvmhv_get_nested(kvm, p->lpid, false);
1347 				if (!nested) {
1348 					gpa = RADIX_PGTABLE_RANGE;
1349 					continue;
1350 				}
1351 				pgt = nested->shadow_pgtable;
1352 			}
1353 		}
1354 		n = 0;
1355 		if (!p->hdr) {
1356 			if (p->lpid > 0)
1357 				n = scnprintf(p->buf, sizeof(p->buf),
1358 					      "\nNested LPID %d: ", p->lpid);
1359 			n += scnprintf(p->buf + n, sizeof(p->buf) - n,
1360 				      "pgdir: %lx\n", (unsigned long)pgt);
1361 			p->hdr = 1;
1362 			goto copy;
1363 		}
1364 
1365 		pgdp = pgt + pgd_index(gpa);
1366 		p4dp = p4d_offset(pgdp, gpa);
1367 		p4d = READ_ONCE(*p4dp);
1368 		if (!(p4d_val(p4d) & _PAGE_PRESENT)) {
1369 			gpa = (gpa & P4D_MASK) + P4D_SIZE;
1370 			continue;
1371 		}
1372 
1373 		pudp = pud_offset(&p4d, gpa);
1374 		pud = READ_ONCE(*pudp);
1375 		if (!(pud_val(pud) & _PAGE_PRESENT)) {
1376 			gpa = (gpa & PUD_MASK) + PUD_SIZE;
1377 			continue;
1378 		}
1379 		if (pud_val(pud) & _PAGE_PTE) {
1380 			pte = pud_val(pud);
1381 			shift = PUD_SHIFT;
1382 			goto leaf;
1383 		}
1384 
1385 		pmdp = pmd_offset(&pud, gpa);
1386 		pmd = READ_ONCE(*pmdp);
1387 		if (!(pmd_val(pmd) & _PAGE_PRESENT)) {
1388 			gpa = (gpa & PMD_MASK) + PMD_SIZE;
1389 			continue;
1390 		}
1391 		if (pmd_val(pmd) & _PAGE_PTE) {
1392 			pte = pmd_val(pmd);
1393 			shift = PMD_SHIFT;
1394 			goto leaf;
1395 		}
1396 
1397 		ptep = pte_offset_kernel(&pmd, gpa);
1398 		pte = pte_val(READ_ONCE(*ptep));
1399 		if (!(pte & _PAGE_PRESENT)) {
1400 			gpa += PAGE_SIZE;
1401 			continue;
1402 		}
1403 		shift = PAGE_SHIFT;
1404 	leaf:
1405 		n = scnprintf(p->buf, sizeof(p->buf),
1406 			      " %lx: %lx %d\n", gpa, pte, shift);
1407 		gpa += 1ul << shift;
1408 	copy:
1409 		p->chars_left = n;
1410 		if (n > len)
1411 			n = len;
1412 		r = copy_to_user(buf, p->buf, n);
1413 		n -= r;
1414 		p->chars_left -= n;
1415 		p->buf_index = n;
1416 		buf += n;
1417 		len -= n;
1418 		ret += n;
1419 		if (r) {
1420 			if (!ret)
1421 				ret = -EFAULT;
1422 			break;
1423 		}
1424 	}
1425 	p->gpa = gpa;
1426 	if (nested)
1427 		kvmhv_put_nested(nested);
1428 
1429  out:
1430 	mutex_unlock(&p->mutex);
1431 	return ret;
1432 }
1433 
1434 static ssize_t debugfs_radix_write(struct file *file, const char __user *buf,
1435 			   size_t len, loff_t *ppos)
1436 {
1437 	return -EACCES;
1438 }
1439 
1440 static const struct file_operations debugfs_radix_fops = {
1441 	.owner	 = THIS_MODULE,
1442 	.open	 = debugfs_radix_open,
1443 	.release = debugfs_radix_release,
1444 	.read	 = debugfs_radix_read,
1445 	.write	 = debugfs_radix_write,
1446 	.llseek	 = generic_file_llseek,
1447 };
1448 
1449 void kvmhv_radix_debugfs_init(struct kvm *kvm)
1450 {
1451 	debugfs_create_file("radix", 0400, kvm->arch.debugfs_dir, kvm,
1452 			    &debugfs_radix_fops);
1453 }
1454 
1455 int kvmppc_radix_init(void)
1456 {
1457 	unsigned long size = sizeof(void *) << RADIX_PTE_INDEX_SIZE;
1458 
1459 	kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, 0, pte_ctor);
1460 	if (!kvm_pte_cache)
1461 		return -ENOMEM;
1462 
1463 	size = sizeof(void *) << RADIX_PMD_INDEX_SIZE;
1464 
1465 	kvm_pmd_cache = kmem_cache_create("kvm-pmd", size, size, 0, pmd_ctor);
1466 	if (!kvm_pmd_cache) {
1467 		kmem_cache_destroy(kvm_pte_cache);
1468 		return -ENOMEM;
1469 	}
1470 
1471 	return 0;
1472 }
1473 
1474 void kvmppc_radix_exit(void)
1475 {
1476 	kmem_cache_destroy(kvm_pte_cache);
1477 	kmem_cache_destroy(kvm_pmd_cache);
1478 }
1479