xref: /linux/arch/arm64/include/asm/kvm_pgtable.h (revision 021bc4b9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2020 Google LLC
4  * Author: Will Deacon <will@kernel.org>
5  */
6 
7 #ifndef __ARM64_KVM_PGTABLE_H__
8 #define __ARM64_KVM_PGTABLE_H__
9 
10 #include <linux/bits.h>
11 #include <linux/kvm_host.h>
12 #include <linux/types.h>
13 
14 #define KVM_PGTABLE_FIRST_LEVEL		-1
15 #define KVM_PGTABLE_LAST_LEVEL		3
16 
17 /*
18  * The largest supported block sizes for KVM (no 52-bit PA support):
19  *  - 4K (level 1):	1GB
20  *  - 16K (level 2):	32MB
21  *  - 64K (level 2):	512MB
22  */
23 #ifdef CONFIG_ARM64_4K_PAGES
24 #define KVM_PGTABLE_MIN_BLOCK_LEVEL	1
25 #else
26 #define KVM_PGTABLE_MIN_BLOCK_LEVEL	2
27 #endif
28 
29 #define kvm_lpa2_is_enabled()		system_supports_lpa2()
30 
31 static inline u64 kvm_get_parange_max(void)
32 {
33 	if (kvm_lpa2_is_enabled() ||
34 	   (IS_ENABLED(CONFIG_ARM64_PA_BITS_52) && PAGE_SHIFT == 16))
35 		return ID_AA64MMFR0_EL1_PARANGE_52;
36 	else
37 		return ID_AA64MMFR0_EL1_PARANGE_48;
38 }
39 
40 static inline u64 kvm_get_parange(u64 mmfr0)
41 {
42 	u64 parange_max = kvm_get_parange_max();
43 	u64 parange = cpuid_feature_extract_unsigned_field(mmfr0,
44 				ID_AA64MMFR0_EL1_PARANGE_SHIFT);
45 	if (parange > parange_max)
46 		parange = parange_max;
47 
48 	return parange;
49 }
50 
51 typedef u64 kvm_pte_t;
52 
53 #define KVM_PTE_VALID			BIT(0)
54 
55 #define KVM_PTE_ADDR_MASK		GENMASK(47, PAGE_SHIFT)
56 #define KVM_PTE_ADDR_51_48		GENMASK(15, 12)
57 #define KVM_PTE_ADDR_MASK_LPA2		GENMASK(49, PAGE_SHIFT)
58 #define KVM_PTE_ADDR_51_50_LPA2		GENMASK(9, 8)
59 
60 #define KVM_PHYS_INVALID		(-1ULL)
61 
62 static inline bool kvm_pte_valid(kvm_pte_t pte)
63 {
64 	return pte & KVM_PTE_VALID;
65 }
66 
67 static inline u64 kvm_pte_to_phys(kvm_pte_t pte)
68 {
69 	u64 pa;
70 
71 	if (kvm_lpa2_is_enabled()) {
72 		pa = pte & KVM_PTE_ADDR_MASK_LPA2;
73 		pa |= FIELD_GET(KVM_PTE_ADDR_51_50_LPA2, pte) << 50;
74 	} else {
75 		pa = pte & KVM_PTE_ADDR_MASK;
76 		if (PAGE_SHIFT == 16)
77 			pa |= FIELD_GET(KVM_PTE_ADDR_51_48, pte) << 48;
78 	}
79 
80 	return pa;
81 }
82 
83 static inline kvm_pte_t kvm_phys_to_pte(u64 pa)
84 {
85 	kvm_pte_t pte;
86 
87 	if (kvm_lpa2_is_enabled()) {
88 		pte = pa & KVM_PTE_ADDR_MASK_LPA2;
89 		pa &= GENMASK(51, 50);
90 		pte |= FIELD_PREP(KVM_PTE_ADDR_51_50_LPA2, pa >> 50);
91 	} else {
92 		pte = pa & KVM_PTE_ADDR_MASK;
93 		if (PAGE_SHIFT == 16) {
94 			pa &= GENMASK(51, 48);
95 			pte |= FIELD_PREP(KVM_PTE_ADDR_51_48, pa >> 48);
96 		}
97 	}
98 
99 	return pte;
100 }
101 
102 static inline kvm_pfn_t kvm_pte_to_pfn(kvm_pte_t pte)
103 {
104 	return __phys_to_pfn(kvm_pte_to_phys(pte));
105 }
106 
107 static inline u64 kvm_granule_shift(s8 level)
108 {
109 	/* Assumes KVM_PGTABLE_LAST_LEVEL is 3 */
110 	return ARM64_HW_PGTABLE_LEVEL_SHIFT(level);
111 }
112 
113 static inline u64 kvm_granule_size(s8 level)
114 {
115 	return BIT(kvm_granule_shift(level));
116 }
117 
118 static inline bool kvm_level_supports_block_mapping(s8 level)
119 {
120 	return level >= KVM_PGTABLE_MIN_BLOCK_LEVEL;
121 }
122 
123 static inline u32 kvm_supported_block_sizes(void)
124 {
125 	s8 level = KVM_PGTABLE_MIN_BLOCK_LEVEL;
126 	u32 r = 0;
127 
128 	for (; level <= KVM_PGTABLE_LAST_LEVEL; level++)
129 		r |= BIT(kvm_granule_shift(level));
130 
131 	return r;
132 }
133 
134 static inline bool kvm_is_block_size_supported(u64 size)
135 {
136 	bool is_power_of_two = IS_ALIGNED(size, size);
137 
138 	return is_power_of_two && (size & kvm_supported_block_sizes());
139 }
140 
141 /**
142  * struct kvm_pgtable_mm_ops - Memory management callbacks.
143  * @zalloc_page:		Allocate a single zeroed memory page.
144  *				The @arg parameter can be used by the walker
145  *				to pass a memcache. The initial refcount of
146  *				the page is 1.
147  * @zalloc_pages_exact:		Allocate an exact number of zeroed memory pages.
148  *				The @size parameter is in bytes, and is rounded
149  *				up to the next page boundary. The resulting
150  *				allocation is physically contiguous.
151  * @free_pages_exact:		Free an exact number of memory pages previously
152  *				allocated by zalloc_pages_exact.
153  * @free_unlinked_table:	Free an unlinked paging structure by unlinking and
154  *				dropping references.
155  * @get_page:			Increment the refcount on a page.
156  * @put_page:			Decrement the refcount on a page. When the
157  *				refcount reaches 0 the page is automatically
158  *				freed.
159  * @page_count:			Return the refcount of a page.
160  * @phys_to_virt:		Convert a physical address into a virtual
161  *				address	mapped in the current context.
162  * @virt_to_phys:		Convert a virtual address mapped in the current
163  *				context into a physical address.
164  * @dcache_clean_inval_poc:	Clean and invalidate the data cache to the PoC
165  *				for the	specified memory address range.
166  * @icache_inval_pou:		Invalidate the instruction cache to the PoU
167  *				for the specified memory address range.
168  */
169 struct kvm_pgtable_mm_ops {
170 	void*		(*zalloc_page)(void *arg);
171 	void*		(*zalloc_pages_exact)(size_t size);
172 	void		(*free_pages_exact)(void *addr, size_t size);
173 	void		(*free_unlinked_table)(void *addr, s8 level);
174 	void		(*get_page)(void *addr);
175 	void		(*put_page)(void *addr);
176 	int		(*page_count)(void *addr);
177 	void*		(*phys_to_virt)(phys_addr_t phys);
178 	phys_addr_t	(*virt_to_phys)(void *addr);
179 	void		(*dcache_clean_inval_poc)(void *addr, size_t size);
180 	void		(*icache_inval_pou)(void *addr, size_t size);
181 };
182 
183 /**
184  * enum kvm_pgtable_stage2_flags - Stage-2 page-table flags.
185  * @KVM_PGTABLE_S2_NOFWB:	Don't enforce Normal-WB even if the CPUs have
186  *				ARM64_HAS_STAGE2_FWB.
187  * @KVM_PGTABLE_S2_IDMAP:	Only use identity mappings.
188  */
189 enum kvm_pgtable_stage2_flags {
190 	KVM_PGTABLE_S2_NOFWB			= BIT(0),
191 	KVM_PGTABLE_S2_IDMAP			= BIT(1),
192 };
193 
194 /**
195  * enum kvm_pgtable_prot - Page-table permissions and attributes.
196  * @KVM_PGTABLE_PROT_X:		Execute permission.
197  * @KVM_PGTABLE_PROT_W:		Write permission.
198  * @KVM_PGTABLE_PROT_R:		Read permission.
199  * @KVM_PGTABLE_PROT_DEVICE:	Device attributes.
200  * @KVM_PGTABLE_PROT_SW0:	Software bit 0.
201  * @KVM_PGTABLE_PROT_SW1:	Software bit 1.
202  * @KVM_PGTABLE_PROT_SW2:	Software bit 2.
203  * @KVM_PGTABLE_PROT_SW3:	Software bit 3.
204  */
205 enum kvm_pgtable_prot {
206 	KVM_PGTABLE_PROT_X			= BIT(0),
207 	KVM_PGTABLE_PROT_W			= BIT(1),
208 	KVM_PGTABLE_PROT_R			= BIT(2),
209 
210 	KVM_PGTABLE_PROT_DEVICE			= BIT(3),
211 
212 	KVM_PGTABLE_PROT_SW0			= BIT(55),
213 	KVM_PGTABLE_PROT_SW1			= BIT(56),
214 	KVM_PGTABLE_PROT_SW2			= BIT(57),
215 	KVM_PGTABLE_PROT_SW3			= BIT(58),
216 };
217 
218 #define KVM_PGTABLE_PROT_RW	(KVM_PGTABLE_PROT_R | KVM_PGTABLE_PROT_W)
219 #define KVM_PGTABLE_PROT_RWX	(KVM_PGTABLE_PROT_RW | KVM_PGTABLE_PROT_X)
220 
221 #define PKVM_HOST_MEM_PROT	KVM_PGTABLE_PROT_RWX
222 #define PKVM_HOST_MMIO_PROT	KVM_PGTABLE_PROT_RW
223 
224 #define PAGE_HYP		KVM_PGTABLE_PROT_RW
225 #define PAGE_HYP_EXEC		(KVM_PGTABLE_PROT_R | KVM_PGTABLE_PROT_X)
226 #define PAGE_HYP_RO		(KVM_PGTABLE_PROT_R)
227 #define PAGE_HYP_DEVICE		(PAGE_HYP | KVM_PGTABLE_PROT_DEVICE)
228 
229 typedef bool (*kvm_pgtable_force_pte_cb_t)(u64 addr, u64 end,
230 					   enum kvm_pgtable_prot prot);
231 
232 /**
233  * enum kvm_pgtable_walk_flags - Flags to control a depth-first page-table walk.
234  * @KVM_PGTABLE_WALK_LEAF:		Visit leaf entries, including invalid
235  *					entries.
236  * @KVM_PGTABLE_WALK_TABLE_PRE:		Visit table entries before their
237  *					children.
238  * @KVM_PGTABLE_WALK_TABLE_POST:	Visit table entries after their
239  *					children.
240  * @KVM_PGTABLE_WALK_SHARED:		Indicates the page-tables may be shared
241  *					with other software walkers.
242  * @KVM_PGTABLE_WALK_HANDLE_FAULT:	Indicates the page-table walk was
243  *					invoked from a fault handler.
244  * @KVM_PGTABLE_WALK_SKIP_BBM_TLBI:	Visit and update table entries
245  *					without Break-before-make's
246  *					TLB invalidation.
247  * @KVM_PGTABLE_WALK_SKIP_CMO:		Visit and update table entries
248  *					without Cache maintenance
249  *					operations required.
250  */
251 enum kvm_pgtable_walk_flags {
252 	KVM_PGTABLE_WALK_LEAF			= BIT(0),
253 	KVM_PGTABLE_WALK_TABLE_PRE		= BIT(1),
254 	KVM_PGTABLE_WALK_TABLE_POST		= BIT(2),
255 	KVM_PGTABLE_WALK_SHARED			= BIT(3),
256 	KVM_PGTABLE_WALK_HANDLE_FAULT		= BIT(4),
257 	KVM_PGTABLE_WALK_SKIP_BBM_TLBI		= BIT(5),
258 	KVM_PGTABLE_WALK_SKIP_CMO		= BIT(6),
259 };
260 
261 struct kvm_pgtable_visit_ctx {
262 	kvm_pte_t				*ptep;
263 	kvm_pte_t				old;
264 	void					*arg;
265 	struct kvm_pgtable_mm_ops		*mm_ops;
266 	u64					start;
267 	u64					addr;
268 	u64					end;
269 	s8					level;
270 	enum kvm_pgtable_walk_flags		flags;
271 };
272 
273 typedef int (*kvm_pgtable_visitor_fn_t)(const struct kvm_pgtable_visit_ctx *ctx,
274 					enum kvm_pgtable_walk_flags visit);
275 
276 static inline bool kvm_pgtable_walk_shared(const struct kvm_pgtable_visit_ctx *ctx)
277 {
278 	return ctx->flags & KVM_PGTABLE_WALK_SHARED;
279 }
280 
281 /**
282  * struct kvm_pgtable_walker - Hook into a page-table walk.
283  * @cb:		Callback function to invoke during the walk.
284  * @arg:	Argument passed to the callback function.
285  * @flags:	Bitwise-OR of flags to identify the entry types on which to
286  *		invoke the callback function.
287  */
288 struct kvm_pgtable_walker {
289 	const kvm_pgtable_visitor_fn_t		cb;
290 	void * const				arg;
291 	const enum kvm_pgtable_walk_flags	flags;
292 };
293 
294 /*
295  * RCU cannot be used in a non-kernel context such as the hyp. As such, page
296  * table walkers used in hyp do not call into RCU and instead use other
297  * synchronization mechanisms (such as a spinlock).
298  */
299 #if defined(__KVM_NVHE_HYPERVISOR__) || defined(__KVM_VHE_HYPERVISOR__)
300 
301 typedef kvm_pte_t *kvm_pteref_t;
302 
303 static inline kvm_pte_t *kvm_dereference_pteref(struct kvm_pgtable_walker *walker,
304 						kvm_pteref_t pteref)
305 {
306 	return pteref;
307 }
308 
309 static inline int kvm_pgtable_walk_begin(struct kvm_pgtable_walker *walker)
310 {
311 	/*
312 	 * Due to the lack of RCU (or a similar protection scheme), only
313 	 * non-shared table walkers are allowed in the hypervisor.
314 	 */
315 	if (walker->flags & KVM_PGTABLE_WALK_SHARED)
316 		return -EPERM;
317 
318 	return 0;
319 }
320 
321 static inline void kvm_pgtable_walk_end(struct kvm_pgtable_walker *walker) {}
322 
323 static inline bool kvm_pgtable_walk_lock_held(void)
324 {
325 	return true;
326 }
327 
328 #else
329 
330 typedef kvm_pte_t __rcu *kvm_pteref_t;
331 
332 static inline kvm_pte_t *kvm_dereference_pteref(struct kvm_pgtable_walker *walker,
333 						kvm_pteref_t pteref)
334 {
335 	return rcu_dereference_check(pteref, !(walker->flags & KVM_PGTABLE_WALK_SHARED));
336 }
337 
338 static inline int kvm_pgtable_walk_begin(struct kvm_pgtable_walker *walker)
339 {
340 	if (walker->flags & KVM_PGTABLE_WALK_SHARED)
341 		rcu_read_lock();
342 
343 	return 0;
344 }
345 
346 static inline void kvm_pgtable_walk_end(struct kvm_pgtable_walker *walker)
347 {
348 	if (walker->flags & KVM_PGTABLE_WALK_SHARED)
349 		rcu_read_unlock();
350 }
351 
352 static inline bool kvm_pgtable_walk_lock_held(void)
353 {
354 	return rcu_read_lock_held();
355 }
356 
357 #endif
358 
359 /**
360  * struct kvm_pgtable - KVM page-table.
361  * @ia_bits:		Maximum input address size, in bits.
362  * @start_level:	Level at which the page-table walk starts.
363  * @pgd:		Pointer to the first top-level entry of the page-table.
364  * @mm_ops:		Memory management callbacks.
365  * @mmu:		Stage-2 KVM MMU struct. Unused for stage-1 page-tables.
366  * @flags:		Stage-2 page-table flags.
367  * @force_pte_cb:	Function that returns true if page level mappings must
368  *			be used instead of block mappings.
369  */
370 struct kvm_pgtable {
371 	u32					ia_bits;
372 	s8					start_level;
373 	kvm_pteref_t				pgd;
374 	struct kvm_pgtable_mm_ops		*mm_ops;
375 
376 	/* Stage-2 only */
377 	struct kvm_s2_mmu			*mmu;
378 	enum kvm_pgtable_stage2_flags		flags;
379 	kvm_pgtable_force_pte_cb_t		force_pte_cb;
380 };
381 
382 /**
383  * kvm_pgtable_hyp_init() - Initialise a hypervisor stage-1 page-table.
384  * @pgt:	Uninitialised page-table structure to initialise.
385  * @va_bits:	Maximum virtual address bits.
386  * @mm_ops:	Memory management callbacks.
387  *
388  * Return: 0 on success, negative error code on failure.
389  */
390 int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits,
391 			 struct kvm_pgtable_mm_ops *mm_ops);
392 
393 /**
394  * kvm_pgtable_hyp_destroy() - Destroy an unused hypervisor stage-1 page-table.
395  * @pgt:	Page-table structure initialised by kvm_pgtable_hyp_init().
396  *
397  * The page-table is assumed to be unreachable by any hardware walkers prior
398  * to freeing and therefore no TLB invalidation is performed.
399  */
400 void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt);
401 
402 /**
403  * kvm_pgtable_hyp_map() - Install a mapping in a hypervisor stage-1 page-table.
404  * @pgt:	Page-table structure initialised by kvm_pgtable_hyp_init().
405  * @addr:	Virtual address at which to place the mapping.
406  * @size:	Size of the mapping.
407  * @phys:	Physical address of the memory to map.
408  * @prot:	Permissions and attributes for the mapping.
409  *
410  * The offset of @addr within a page is ignored, @size is rounded-up to
411  * the next page boundary and @phys is rounded-down to the previous page
412  * boundary.
413  *
414  * If device attributes are not explicitly requested in @prot, then the
415  * mapping will be normal, cacheable. Attempts to install a new mapping
416  * for a virtual address that is already mapped will be rejected with an
417  * error and a WARN().
418  *
419  * Return: 0 on success, negative error code on failure.
420  */
421 int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
422 			enum kvm_pgtable_prot prot);
423 
424 /**
425  * kvm_pgtable_hyp_unmap() - Remove a mapping from a hypervisor stage-1 page-table.
426  * @pgt:	Page-table structure initialised by kvm_pgtable_hyp_init().
427  * @addr:	Virtual address from which to remove the mapping.
428  * @size:	Size of the mapping.
429  *
430  * The offset of @addr within a page is ignored, @size is rounded-up to
431  * the next page boundary and @phys is rounded-down to the previous page
432  * boundary.
433  *
434  * TLB invalidation is performed for each page-table entry cleared during the
435  * unmapping operation and the reference count for the page-table page
436  * containing the cleared entry is decremented, with unreferenced pages being
437  * freed. The unmapping operation will stop early if it encounters either an
438  * invalid page-table entry or a valid block mapping which maps beyond the range
439  * being unmapped.
440  *
441  * Return: Number of bytes unmapped, which may be 0.
442  */
443 u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size);
444 
445 /**
446  * kvm_get_vtcr() - Helper to construct VTCR_EL2
447  * @mmfr0:	Sanitized value of SYS_ID_AA64MMFR0_EL1 register.
448  * @mmfr1:	Sanitized value of SYS_ID_AA64MMFR1_EL1 register.
449  * @phys_shfit:	Value to set in VTCR_EL2.T0SZ.
450  *
451  * The VTCR value is common across all the physical CPUs on the system.
452  * We use system wide sanitised values to fill in different fields,
453  * except for Hardware Management of Access Flags. HA Flag is set
454  * unconditionally on all CPUs, as it is safe to run with or without
455  * the feature and the bit is RES0 on CPUs that don't support it.
456  *
457  * Return: VTCR_EL2 value
458  */
459 u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift);
460 
461 /**
462  * kvm_pgtable_stage2_pgd_size() - Helper to compute size of a stage-2 PGD
463  * @vtcr:	Content of the VTCR register.
464  *
465  * Return: the size (in bytes) of the stage-2 PGD
466  */
467 size_t kvm_pgtable_stage2_pgd_size(u64 vtcr);
468 
469 /**
470  * __kvm_pgtable_stage2_init() - Initialise a guest stage-2 page-table.
471  * @pgt:	Uninitialised page-table structure to initialise.
472  * @mmu:	S2 MMU context for this S2 translation
473  * @mm_ops:	Memory management callbacks.
474  * @flags:	Stage-2 configuration flags.
475  * @force_pte_cb: Function that returns true if page level mappings must
476  *		be used instead of block mappings.
477  *
478  * Return: 0 on success, negative error code on failure.
479  */
480 int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu,
481 			      struct kvm_pgtable_mm_ops *mm_ops,
482 			      enum kvm_pgtable_stage2_flags flags,
483 			      kvm_pgtable_force_pte_cb_t force_pte_cb);
484 
485 #define kvm_pgtable_stage2_init(pgt, mmu, mm_ops) \
486 	__kvm_pgtable_stage2_init(pgt, mmu, mm_ops, 0, NULL)
487 
488 /**
489  * kvm_pgtable_stage2_destroy() - Destroy an unused guest stage-2 page-table.
490  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
491  *
492  * The page-table is assumed to be unreachable by any hardware walkers prior
493  * to freeing and therefore no TLB invalidation is performed.
494  */
495 void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt);
496 
497 /**
498  * kvm_pgtable_stage2_free_unlinked() - Free an unlinked stage-2 paging structure.
499  * @mm_ops:	Memory management callbacks.
500  * @pgtable:	Unlinked stage-2 paging structure to be freed.
501  * @level:	Level of the stage-2 paging structure to be freed.
502  *
503  * The page-table is assumed to be unreachable by any hardware walkers prior to
504  * freeing and therefore no TLB invalidation is performed.
505  */
506 void kvm_pgtable_stage2_free_unlinked(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, s8 level);
507 
508 /**
509  * kvm_pgtable_stage2_create_unlinked() - Create an unlinked stage-2 paging structure.
510  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
511  * @phys:	Physical address of the memory to map.
512  * @level:	Starting level of the stage-2 paging structure to be created.
513  * @prot:	Permissions and attributes for the mapping.
514  * @mc:		Cache of pre-allocated and zeroed memory from which to allocate
515  *		page-table pages.
516  * @force_pte:  Force mappings to PAGE_SIZE granularity.
517  *
518  * Returns an unlinked page-table tree.  This new page-table tree is
519  * not reachable (i.e., it is unlinked) from the root pgd and it's
520  * therefore unreachableby the hardware page-table walker. No TLB
521  * invalidation or CMOs are performed.
522  *
523  * If device attributes are not explicitly requested in @prot, then the
524  * mapping will be normal, cacheable.
525  *
526  * Return: The fully populated (unlinked) stage-2 paging structure, or
527  * an ERR_PTR(error) on failure.
528  */
529 kvm_pte_t *kvm_pgtable_stage2_create_unlinked(struct kvm_pgtable *pgt,
530 					      u64 phys, s8 level,
531 					      enum kvm_pgtable_prot prot,
532 					      void *mc, bool force_pte);
533 
534 /**
535  * kvm_pgtable_stage2_map() - Install a mapping in a guest stage-2 page-table.
536  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
537  * @addr:	Intermediate physical address at which to place the mapping.
538  * @size:	Size of the mapping.
539  * @phys:	Physical address of the memory to map.
540  * @prot:	Permissions and attributes for the mapping.
541  * @mc:		Cache of pre-allocated and zeroed memory from which to allocate
542  *		page-table pages.
543  * @flags:	Flags to control the page-table walk (ex. a shared walk)
544  *
545  * The offset of @addr within a page is ignored, @size is rounded-up to
546  * the next page boundary and @phys is rounded-down to the previous page
547  * boundary.
548  *
549  * If device attributes are not explicitly requested in @prot, then the
550  * mapping will be normal, cacheable.
551  *
552  * Note that the update of a valid leaf PTE in this function will be aborted,
553  * if it's trying to recreate the exact same mapping or only change the access
554  * permissions. Instead, the vCPU will exit one more time from guest if still
555  * needed and then go through the path of relaxing permissions.
556  *
557  * Note that this function will both coalesce existing table entries and split
558  * existing block mappings, relying on page-faults to fault back areas outside
559  * of the new mapping lazily.
560  *
561  * Return: 0 on success, negative error code on failure.
562  */
563 int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,
564 			   u64 phys, enum kvm_pgtable_prot prot,
565 			   void *mc, enum kvm_pgtable_walk_flags flags);
566 
567 /**
568  * kvm_pgtable_stage2_set_owner() - Unmap and annotate pages in the IPA space to
569  *				    track ownership.
570  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
571  * @addr:	Base intermediate physical address to annotate.
572  * @size:	Size of the annotated range.
573  * @mc:		Cache of pre-allocated and zeroed memory from which to allocate
574  *		page-table pages.
575  * @owner_id:	Unique identifier for the owner of the page.
576  *
577  * By default, all page-tables are owned by identifier 0. This function can be
578  * used to mark portions of the IPA space as owned by other entities. When a
579  * stage 2 is used with identity-mappings, these annotations allow to use the
580  * page-table data structure as a simple rmap.
581  *
582  * Return: 0 on success, negative error code on failure.
583  */
584 int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size,
585 				 void *mc, u8 owner_id);
586 
587 /**
588  * kvm_pgtable_stage2_unmap() - Remove a mapping from a guest stage-2 page-table.
589  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
590  * @addr:	Intermediate physical address from which to remove the mapping.
591  * @size:	Size of the mapping.
592  *
593  * The offset of @addr within a page is ignored and @size is rounded-up to
594  * the next page boundary.
595  *
596  * TLB invalidation is performed for each page-table entry cleared during the
597  * unmapping operation and the reference count for the page-table page
598  * containing the cleared entry is decremented, with unreferenced pages being
599  * freed. Unmapping a cacheable page will ensure that it is clean to the PoC if
600  * FWB is not supported by the CPU.
601  *
602  * Return: 0 on success, negative error code on failure.
603  */
604 int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size);
605 
606 /**
607  * kvm_pgtable_stage2_wrprotect() - Write-protect guest stage-2 address range
608  *                                  without TLB invalidation.
609  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
610  * @addr:	Intermediate physical address from which to write-protect,
611  * @size:	Size of the range.
612  *
613  * The offset of @addr within a page is ignored and @size is rounded-up to
614  * the next page boundary.
615  *
616  * Note that it is the caller's responsibility to invalidate the TLB after
617  * calling this function to ensure that the updated permissions are visible
618  * to the CPUs.
619  *
620  * Return: 0 on success, negative error code on failure.
621  */
622 int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size);
623 
624 /**
625  * kvm_pgtable_stage2_mkyoung() - Set the access flag in a page-table entry.
626  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
627  * @addr:	Intermediate physical address to identify the page-table entry.
628  *
629  * The offset of @addr within a page is ignored.
630  *
631  * If there is a valid, leaf page-table entry used to translate @addr, then
632  * set the access flag in that entry.
633  *
634  * Return: The old page-table entry prior to setting the flag, 0 on failure.
635  */
636 kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr);
637 
638 /**
639  * kvm_pgtable_stage2_test_clear_young() - Test and optionally clear the access
640  *					   flag in a page-table entry.
641  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
642  * @addr:	Intermediate physical address to identify the page-table entry.
643  * @size:	Size of the address range to visit.
644  * @mkold:	True if the access flag should be cleared.
645  *
646  * The offset of @addr within a page is ignored.
647  *
648  * Tests and conditionally clears the access flag for every valid, leaf
649  * page-table entry used to translate the range [@addr, @addr + @size).
650  *
651  * Note that it is the caller's responsibility to invalidate the TLB after
652  * calling this function to ensure that the updated permissions are visible
653  * to the CPUs.
654  *
655  * Return: True if any of the visited PTEs had the access flag set.
656  */
657 bool kvm_pgtable_stage2_test_clear_young(struct kvm_pgtable *pgt, u64 addr,
658 					 u64 size, bool mkold);
659 
660 /**
661  * kvm_pgtable_stage2_relax_perms() - Relax the permissions enforced by a
662  *				      page-table entry.
663  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
664  * @addr:	Intermediate physical address to identify the page-table entry.
665  * @prot:	Additional permissions to grant for the mapping.
666  *
667  * The offset of @addr within a page is ignored.
668  *
669  * If there is a valid, leaf page-table entry used to translate @addr, then
670  * relax the permissions in that entry according to the read, write and
671  * execute permissions specified by @prot. No permissions are removed, and
672  * TLB invalidation is performed after updating the entry. Software bits cannot
673  * be set or cleared using kvm_pgtable_stage2_relax_perms().
674  *
675  * Return: 0 on success, negative error code on failure.
676  */
677 int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr,
678 				   enum kvm_pgtable_prot prot);
679 
680 /**
681  * kvm_pgtable_stage2_flush_range() - Clean and invalidate data cache to Point
682  * 				      of Coherency for guest stage-2 address
683  *				      range.
684  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
685  * @addr:	Intermediate physical address from which to flush.
686  * @size:	Size of the range.
687  *
688  * The offset of @addr within a page is ignored and @size is rounded-up to
689  * the next page boundary.
690  *
691  * Return: 0 on success, negative error code on failure.
692  */
693 int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size);
694 
695 /**
696  * kvm_pgtable_stage2_split() - Split a range of huge pages into leaf PTEs pointing
697  *				to PAGE_SIZE guest pages.
698  * @pgt:	 Page-table structure initialised by kvm_pgtable_stage2_init().
699  * @addr:	 Intermediate physical address from which to split.
700  * @size:	 Size of the range.
701  * @mc:		 Cache of pre-allocated and zeroed memory from which to allocate
702  *		 page-table pages.
703  *
704  * The function tries to split any level 1 or 2 entry that overlaps
705  * with the input range (given by @addr and @size).
706  *
707  * Return: 0 on success, negative error code on failure. Note that
708  * kvm_pgtable_stage2_split() is best effort: it tries to break as many
709  * blocks in the input range as allowed by @mc_capacity.
710  */
711 int kvm_pgtable_stage2_split(struct kvm_pgtable *pgt, u64 addr, u64 size,
712 			     struct kvm_mmu_memory_cache *mc);
713 
714 /**
715  * kvm_pgtable_walk() - Walk a page-table.
716  * @pgt:	Page-table structure initialised by kvm_pgtable_*_init().
717  * @addr:	Input address for the start of the walk.
718  * @size:	Size of the range to walk.
719  * @walker:	Walker callback description.
720  *
721  * The offset of @addr within a page is ignored and @size is rounded-up to
722  * the next page boundary.
723  *
724  * The walker will walk the page-table entries corresponding to the input
725  * address range specified, visiting entries according to the walker flags.
726  * Invalid entries are treated as leaf entries. The visited page table entry is
727  * reloaded after invoking the walker callback, allowing the walker to descend
728  * into a newly installed table.
729  *
730  * Returning a negative error code from the walker callback function will
731  * terminate the walk immediately with the same error code.
732  *
733  * Return: 0 on success, negative error code on failure.
734  */
735 int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size,
736 		     struct kvm_pgtable_walker *walker);
737 
738 /**
739  * kvm_pgtable_get_leaf() - Walk a page-table and retrieve the leaf entry
740  *			    with its level.
741  * @pgt:	Page-table structure initialised by kvm_pgtable_*_init()
742  *		or a similar initialiser.
743  * @addr:	Input address for the start of the walk.
744  * @ptep:	Pointer to storage for the retrieved PTE.
745  * @level:	Pointer to storage for the level of the retrieved PTE.
746  *
747  * The offset of @addr within a page is ignored.
748  *
749  * The walker will walk the page-table entries corresponding to the input
750  * address specified, retrieving the leaf corresponding to this address.
751  * Invalid entries are treated as leaf entries.
752  *
753  * Return: 0 on success, negative error code on failure.
754  */
755 int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr,
756 			 kvm_pte_t *ptep, s8 *level);
757 
758 /**
759  * kvm_pgtable_stage2_pte_prot() - Retrieve the protection attributes of a
760  *				   stage-2 Page-Table Entry.
761  * @pte:	Page-table entry
762  *
763  * Return: protection attributes of the page-table entry in the enum
764  *	   kvm_pgtable_prot format.
765  */
766 enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte);
767 
768 /**
769  * kvm_pgtable_hyp_pte_prot() - Retrieve the protection attributes of a stage-1
770  *				Page-Table Entry.
771  * @pte:	Page-table entry
772  *
773  * Return: protection attributes of the page-table entry in the enum
774  *	   kvm_pgtable_prot format.
775  */
776 enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
777 
778 /**
779  * kvm_tlb_flush_vmid_range() - Invalidate/flush a range of TLB entries
780  *
781  * @mmu:	Stage-2 KVM MMU struct
782  * @addr:	The base Intermediate physical address from which to invalidate
783  * @size:	Size of the range from the base to invalidate
784  */
785 void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
786 				phys_addr_t addr, size_t size);
787 #endif	/* __ARM64_KVM_PGTABLE_H__ */
788