xref: /linux/arch/arm64/kvm/hyp/nvhe/mem_protect.c (revision 4ea7c1717f3f2344f7a1cdab4f5875cfa89c87a9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2020 Google LLC
4  * Author: Quentin Perret <qperret@google.com>
5  */
6 
7 #include <linux/kvm_host.h>
8 #include <asm/kvm_emulate.h>
9 #include <asm/kvm_hyp.h>
10 #include <asm/kvm_mmu.h>
11 #include <asm/kvm_pgtable.h>
12 #include <asm/kvm_pkvm.h>
13 #include <asm/stage2_pgtable.h>
14 
15 #include <hyp/fault.h>
16 
17 #include <nvhe/gfp.h>
18 #include <nvhe/memory.h>
19 #include <nvhe/mem_protect.h>
20 #include <nvhe/mm.h>
21 
22 #define KVM_HOST_S2_FLAGS (KVM_PGTABLE_S2_NOFWB | KVM_PGTABLE_S2_IDMAP)
23 
24 struct host_mmu host_mmu;
25 
26 static struct hyp_pool host_s2_pool;
27 
28 static DEFINE_PER_CPU(struct pkvm_hyp_vm *, __current_vm);
29 #define current_vm (*this_cpu_ptr(&__current_vm))
30 
guest_lock_component(struct pkvm_hyp_vm * vm)31 static void guest_lock_component(struct pkvm_hyp_vm *vm)
32 {
33 	hyp_spin_lock(&vm->lock);
34 	current_vm = vm;
35 }
36 
guest_unlock_component(struct pkvm_hyp_vm * vm)37 static void guest_unlock_component(struct pkvm_hyp_vm *vm)
38 {
39 	current_vm = NULL;
40 	hyp_spin_unlock(&vm->lock);
41 }
42 
host_lock_component(void)43 static void host_lock_component(void)
44 {
45 	hyp_spin_lock(&host_mmu.lock);
46 }
47 
host_unlock_component(void)48 static void host_unlock_component(void)
49 {
50 	hyp_spin_unlock(&host_mmu.lock);
51 }
52 
hyp_lock_component(void)53 static void hyp_lock_component(void)
54 {
55 	hyp_spin_lock(&pkvm_pgd_lock);
56 }
57 
hyp_unlock_component(void)58 static void hyp_unlock_component(void)
59 {
60 	hyp_spin_unlock(&pkvm_pgd_lock);
61 }
62 
63 #define for_each_hyp_page(__p, __st, __sz)				\
64 	for (struct hyp_page *__p = hyp_phys_to_page(__st),		\
65 			     *__e = __p + ((__sz) >> PAGE_SHIFT);	\
66 	     __p < __e; __p++)
67 
host_s2_zalloc_pages_exact(size_t size)68 static void *host_s2_zalloc_pages_exact(size_t size)
69 {
70 	void *addr = hyp_alloc_pages(&host_s2_pool, get_order(size));
71 
72 	hyp_split_page(hyp_virt_to_page(addr));
73 
74 	/*
75 	 * The size of concatenated PGDs is always a power of two of PAGE_SIZE,
76 	 * so there should be no need to free any of the tail pages to make the
77 	 * allocation exact.
78 	 */
79 	WARN_ON(size != (PAGE_SIZE << get_order(size)));
80 
81 	return addr;
82 }
83 
host_s2_zalloc_page(void * pool)84 static void *host_s2_zalloc_page(void *pool)
85 {
86 	return hyp_alloc_pages(pool, 0);
87 }
88 
host_s2_get_page(void * addr)89 static void host_s2_get_page(void *addr)
90 {
91 	hyp_get_page(&host_s2_pool, addr);
92 }
93 
host_s2_put_page(void * addr)94 static void host_s2_put_page(void *addr)
95 {
96 	hyp_put_page(&host_s2_pool, addr);
97 }
98 
host_s2_free_unlinked_table(void * addr,s8 level)99 static void host_s2_free_unlinked_table(void *addr, s8 level)
100 {
101 	kvm_pgtable_stage2_free_unlinked(&host_mmu.mm_ops, addr, level);
102 }
103 
prepare_s2_pool(void * pgt_pool_base)104 static int prepare_s2_pool(void *pgt_pool_base)
105 {
106 	unsigned long nr_pages, pfn;
107 	int ret;
108 
109 	pfn = hyp_virt_to_pfn(pgt_pool_base);
110 	nr_pages = host_s2_pgtable_pages();
111 	ret = hyp_pool_init(&host_s2_pool, pfn, nr_pages, 0);
112 	if (ret)
113 		return ret;
114 
115 	host_mmu.mm_ops = (struct kvm_pgtable_mm_ops) {
116 		.zalloc_pages_exact = host_s2_zalloc_pages_exact,
117 		.zalloc_page = host_s2_zalloc_page,
118 		.free_unlinked_table = host_s2_free_unlinked_table,
119 		.phys_to_virt = hyp_phys_to_virt,
120 		.virt_to_phys = hyp_virt_to_phys,
121 		.page_count = hyp_page_count,
122 		.get_page = host_s2_get_page,
123 		.put_page = host_s2_put_page,
124 	};
125 
126 	return 0;
127 }
128 
prepare_host_vtcr(void)129 static void prepare_host_vtcr(void)
130 {
131 	u32 parange, phys_shift;
132 
133 	/* The host stage 2 is id-mapped, so use parange for T0SZ */
134 	parange = kvm_get_parange(id_aa64mmfr0_el1_sys_val);
135 	phys_shift = id_aa64mmfr0_parange_to_phys_shift(parange);
136 
137 	host_mmu.arch.mmu.vtcr = kvm_get_vtcr(id_aa64mmfr0_el1_sys_val,
138 					      id_aa64mmfr1_el1_sys_val, phys_shift);
139 }
140 
141 static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot prot);
142 
kvm_host_prepare_stage2(void * pgt_pool_base)143 int kvm_host_prepare_stage2(void *pgt_pool_base)
144 {
145 	struct kvm_s2_mmu *mmu = &host_mmu.arch.mmu;
146 	int ret;
147 
148 	prepare_host_vtcr();
149 	hyp_spin_lock_init(&host_mmu.lock);
150 	mmu->arch = &host_mmu.arch;
151 
152 	ret = prepare_s2_pool(pgt_pool_base);
153 	if (ret)
154 		return ret;
155 
156 	ret = __kvm_pgtable_stage2_init(&host_mmu.pgt, mmu,
157 					&host_mmu.mm_ops, KVM_HOST_S2_FLAGS,
158 					host_stage2_force_pte_cb);
159 	if (ret)
160 		return ret;
161 
162 	mmu->pgd_phys = __hyp_pa(host_mmu.pgt.pgd);
163 	mmu->pgt = &host_mmu.pgt;
164 	atomic64_set(&mmu->vmid.id, 0);
165 
166 	return 0;
167 }
168 
guest_s2_zalloc_pages_exact(size_t size)169 static void *guest_s2_zalloc_pages_exact(size_t size)
170 {
171 	void *addr = hyp_alloc_pages(&current_vm->pool, get_order(size));
172 
173 	WARN_ON(size != (PAGE_SIZE << get_order(size)));
174 	hyp_split_page(hyp_virt_to_page(addr));
175 
176 	return addr;
177 }
178 
guest_s2_free_pages_exact(void * addr,unsigned long size)179 static void guest_s2_free_pages_exact(void *addr, unsigned long size)
180 {
181 	u8 order = get_order(size);
182 	unsigned int i;
183 
184 	for (i = 0; i < (1 << order); i++)
185 		hyp_put_page(&current_vm->pool, addr + (i * PAGE_SIZE));
186 }
187 
guest_s2_zalloc_page(void * mc)188 static void *guest_s2_zalloc_page(void *mc)
189 {
190 	struct hyp_page *p;
191 	void *addr;
192 
193 	addr = hyp_alloc_pages(&current_vm->pool, 0);
194 	if (addr)
195 		return addr;
196 
197 	addr = pop_hyp_memcache(mc, hyp_phys_to_virt);
198 	if (!addr)
199 		return addr;
200 
201 	memset(addr, 0, PAGE_SIZE);
202 	p = hyp_virt_to_page(addr);
203 	p->refcount = 1;
204 	p->order = 0;
205 
206 	return addr;
207 }
208 
guest_s2_get_page(void * addr)209 static void guest_s2_get_page(void *addr)
210 {
211 	hyp_get_page(&current_vm->pool, addr);
212 }
213 
guest_s2_put_page(void * addr)214 static void guest_s2_put_page(void *addr)
215 {
216 	hyp_put_page(&current_vm->pool, addr);
217 }
218 
__apply_guest_page(void * va,size_t size,void (* func)(void * addr,size_t size))219 static void __apply_guest_page(void *va, size_t size,
220 			       void (*func)(void *addr, size_t size))
221 {
222 	size += va - PTR_ALIGN_DOWN(va, PAGE_SIZE);
223 	va = PTR_ALIGN_DOWN(va, PAGE_SIZE);
224 	size = PAGE_ALIGN(size);
225 
226 	while (size) {
227 		size_t map_size = PAGE_SIZE;
228 		void *map;
229 
230 		if (IS_ALIGNED((unsigned long)va, PMD_SIZE) && size >= PMD_SIZE)
231 			map = hyp_fixblock_map(__hyp_pa(va), &map_size);
232 		else
233 			map = hyp_fixmap_map(__hyp_pa(va));
234 
235 		func(map, map_size);
236 
237 		if (map_size == PMD_SIZE)
238 			hyp_fixblock_unmap();
239 		else
240 			hyp_fixmap_unmap();
241 
242 		size -= map_size;
243 		va += map_size;
244 	}
245 }
246 
clean_dcache_guest_page(void * va,size_t size)247 static void clean_dcache_guest_page(void *va, size_t size)
248 {
249 	__apply_guest_page(va, size, __clean_dcache_guest_page);
250 }
251 
invalidate_icache_guest_page(void * va,size_t size)252 static void invalidate_icache_guest_page(void *va, size_t size)
253 {
254 	__apply_guest_page(va, size, __invalidate_icache_guest_page);
255 }
256 
kvm_guest_prepare_stage2(struct pkvm_hyp_vm * vm,void * pgd)257 int kvm_guest_prepare_stage2(struct pkvm_hyp_vm *vm, void *pgd)
258 {
259 	struct kvm_s2_mmu *mmu = &vm->kvm.arch.mmu;
260 	unsigned long nr_pages;
261 	int ret;
262 
263 	nr_pages = kvm_pgtable_stage2_pgd_size(mmu->vtcr) >> PAGE_SHIFT;
264 	ret = hyp_pool_init(&vm->pool, hyp_virt_to_pfn(pgd), nr_pages, 0);
265 	if (ret)
266 		return ret;
267 
268 	hyp_spin_lock_init(&vm->lock);
269 	vm->mm_ops = (struct kvm_pgtable_mm_ops) {
270 		.zalloc_pages_exact	= guest_s2_zalloc_pages_exact,
271 		.free_pages_exact	= guest_s2_free_pages_exact,
272 		.zalloc_page		= guest_s2_zalloc_page,
273 		.phys_to_virt		= hyp_phys_to_virt,
274 		.virt_to_phys		= hyp_virt_to_phys,
275 		.page_count		= hyp_page_count,
276 		.get_page		= guest_s2_get_page,
277 		.put_page		= guest_s2_put_page,
278 		.dcache_clean_inval_poc	= clean_dcache_guest_page,
279 		.icache_inval_pou	= invalidate_icache_guest_page,
280 	};
281 
282 	guest_lock_component(vm);
283 	ret = __kvm_pgtable_stage2_init(mmu->pgt, mmu, &vm->mm_ops, 0, NULL);
284 	guest_unlock_component(vm);
285 	if (ret)
286 		return ret;
287 
288 	vm->kvm.arch.mmu.pgd_phys = __hyp_pa(vm->pgt.pgd);
289 
290 	return 0;
291 }
292 
reclaim_pgtable_pages(struct pkvm_hyp_vm * vm,struct kvm_hyp_memcache * mc)293 void reclaim_pgtable_pages(struct pkvm_hyp_vm *vm, struct kvm_hyp_memcache *mc)
294 {
295 	struct hyp_page *page;
296 	void *addr;
297 
298 	/* Dump all pgtable pages in the hyp_pool */
299 	guest_lock_component(vm);
300 	kvm_pgtable_stage2_destroy(&vm->pgt);
301 	vm->kvm.arch.mmu.pgd_phys = 0ULL;
302 	guest_unlock_component(vm);
303 
304 	/* Drain the hyp_pool into the memcache */
305 	addr = hyp_alloc_pages(&vm->pool, 0);
306 	while (addr) {
307 		page = hyp_virt_to_page(addr);
308 		page->refcount = 0;
309 		page->order = 0;
310 		push_hyp_memcache(mc, addr, hyp_virt_to_phys);
311 		WARN_ON(__pkvm_hyp_donate_host(hyp_virt_to_pfn(addr), 1));
312 		addr = hyp_alloc_pages(&vm->pool, 0);
313 	}
314 }
315 
__pkvm_prot_finalize(void)316 int __pkvm_prot_finalize(void)
317 {
318 	struct kvm_s2_mmu *mmu = &host_mmu.arch.mmu;
319 	struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params);
320 
321 	if (params->hcr_el2 & HCR_VM)
322 		return -EPERM;
323 
324 	params->vttbr = kvm_get_vttbr(mmu);
325 	params->vtcr = mmu->vtcr;
326 	params->hcr_el2 |= HCR_VM;
327 
328 	/*
329 	 * The CMO below not only cleans the updated params to the
330 	 * PoC, but also provides the DSB that ensures ongoing
331 	 * page-table walks that have started before we trapped to EL2
332 	 * have completed.
333 	 */
334 	kvm_flush_dcache_to_poc(params, sizeof(*params));
335 
336 	write_sysreg_hcr(params->hcr_el2);
337 	__load_stage2(&host_mmu.arch.mmu, &host_mmu.arch);
338 
339 	/*
340 	 * Make sure to have an ISB before the TLB maintenance below but only
341 	 * when __load_stage2() doesn't include one already.
342 	 */
343 	asm(ALTERNATIVE("isb", "nop", ARM64_WORKAROUND_SPECULATIVE_AT));
344 
345 	/* Invalidate stale HCR bits that may be cached in TLBs */
346 	__tlbi(vmalls12e1);
347 	dsb(nsh);
348 	isb();
349 
350 	return 0;
351 }
352 
host_stage2_unmap_dev_all(void)353 static int host_stage2_unmap_dev_all(void)
354 {
355 	struct kvm_pgtable *pgt = &host_mmu.pgt;
356 	struct memblock_region *reg;
357 	u64 addr = 0;
358 	int i, ret;
359 
360 	/* Unmap all non-memory regions to recycle the pages */
361 	for (i = 0; i < hyp_memblock_nr; i++, addr = reg->base + reg->size) {
362 		reg = &hyp_memory[i];
363 		ret = kvm_pgtable_stage2_unmap(pgt, addr, reg->base - addr);
364 		if (ret)
365 			return ret;
366 	}
367 	return kvm_pgtable_stage2_unmap(pgt, addr, BIT(pgt->ia_bits) - addr);
368 }
369 
370 /*
371  * Ensure the PFN range is contained within PA-range.
372  *
373  * This check is also robust to overflows and is therefore a requirement before
374  * using a pfn/nr_pages pair from an untrusted source.
375  */
pfn_range_is_valid(u64 pfn,u64 nr_pages)376 static bool pfn_range_is_valid(u64 pfn, u64 nr_pages)
377 {
378 	u64 limit = BIT(kvm_phys_shift(&host_mmu.arch.mmu) - PAGE_SHIFT);
379 
380 	return pfn < limit && ((limit - pfn) >= nr_pages);
381 }
382 
383 struct kvm_mem_range {
384 	u64 start;
385 	u64 end;
386 };
387 
find_mem_range(phys_addr_t addr,struct kvm_mem_range * range)388 static struct memblock_region *find_mem_range(phys_addr_t addr, struct kvm_mem_range *range)
389 {
390 	int cur, left = 0, right = hyp_memblock_nr;
391 	struct memblock_region *reg;
392 	phys_addr_t end;
393 
394 	range->start = 0;
395 	range->end = ULONG_MAX;
396 
397 	/* The list of memblock regions is sorted, binary search it */
398 	while (left < right) {
399 		cur = (left + right) >> 1;
400 		reg = &hyp_memory[cur];
401 		end = reg->base + reg->size;
402 		if (addr < reg->base) {
403 			right = cur;
404 			range->end = reg->base;
405 		} else if (addr >= end) {
406 			left = cur + 1;
407 			range->start = end;
408 		} else {
409 			range->start = reg->base;
410 			range->end = end;
411 			return reg;
412 		}
413 	}
414 
415 	return NULL;
416 }
417 
addr_is_memory(phys_addr_t phys)418 bool addr_is_memory(phys_addr_t phys)
419 {
420 	struct kvm_mem_range range;
421 
422 	return !!find_mem_range(phys, &range);
423 }
424 
is_in_mem_range(u64 addr,struct kvm_mem_range * range)425 static bool is_in_mem_range(u64 addr, struct kvm_mem_range *range)
426 {
427 	return range->start <= addr && addr < range->end;
428 }
429 
check_range_allowed_memory(u64 start,u64 end)430 static int check_range_allowed_memory(u64 start, u64 end)
431 {
432 	struct memblock_region *reg;
433 	struct kvm_mem_range range;
434 
435 	/*
436 	 * Callers can't check the state of a range that overlaps memory and
437 	 * MMIO regions, so ensure [start, end[ is in the same kvm_mem_range.
438 	 */
439 	reg = find_mem_range(start, &range);
440 	if (!is_in_mem_range(end - 1, &range))
441 		return -EINVAL;
442 
443 	if (!reg || reg->flags & MEMBLOCK_NOMAP)
444 		return -EPERM;
445 
446 	return 0;
447 }
448 
range_is_memory(u64 start,u64 end)449 static bool range_is_memory(u64 start, u64 end)
450 {
451 	struct kvm_mem_range r;
452 
453 	if (!find_mem_range(start, &r))
454 		return false;
455 
456 	return is_in_mem_range(end - 1, &r);
457 }
458 
__host_stage2_idmap(u64 start,u64 end,enum kvm_pgtable_prot prot)459 static inline int __host_stage2_idmap(u64 start, u64 end,
460 				      enum kvm_pgtable_prot prot)
461 {
462 	return kvm_pgtable_stage2_map(&host_mmu.pgt, start, end - start, start,
463 				      prot, &host_s2_pool, 0);
464 }
465 
466 /*
467  * The pool has been provided with enough pages to cover all of memory with
468  * page granularity, but it is difficult to know how much of the MMIO range
469  * we will need to cover upfront, so we may need to 'recycle' the pages if we
470  * run out.
471  */
472 #define host_stage2_try(fn, ...)					\
473 	({								\
474 		int __ret;						\
475 		hyp_assert_lock_held(&host_mmu.lock);			\
476 		__ret = fn(__VA_ARGS__);				\
477 		if (__ret == -ENOMEM) {					\
478 			__ret = host_stage2_unmap_dev_all();		\
479 			if (!__ret)					\
480 				__ret = fn(__VA_ARGS__);		\
481 		}							\
482 		__ret;							\
483 	 })
484 
range_included(struct kvm_mem_range * child,struct kvm_mem_range * parent)485 static inline bool range_included(struct kvm_mem_range *child,
486 				  struct kvm_mem_range *parent)
487 {
488 	return parent->start <= child->start && child->end <= parent->end;
489 }
490 
host_stage2_adjust_range(u64 addr,struct kvm_mem_range * range)491 static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range)
492 {
493 	struct kvm_mem_range cur;
494 	kvm_pte_t pte;
495 	u64 granule;
496 	s8 level;
497 	int ret;
498 
499 	hyp_assert_lock_held(&host_mmu.lock);
500 	ret = kvm_pgtable_get_leaf(&host_mmu.pgt, addr, &pte, &level);
501 	if (ret)
502 		return ret;
503 
504 	if (kvm_pte_valid(pte))
505 		return -EAGAIN;
506 
507 	if (pte) {
508 		WARN_ON(addr_is_memory(addr) &&
509 			get_host_state(hyp_phys_to_page(addr)) != PKVM_NOPAGE);
510 		return -EPERM;
511 	}
512 
513 	for (; level <= KVM_PGTABLE_LAST_LEVEL; level++) {
514 		if (!kvm_level_supports_block_mapping(level))
515 			continue;
516 		granule = kvm_granule_size(level);
517 		cur.start = ALIGN_DOWN(addr, granule);
518 		cur.end = cur.start + granule;
519 		if (!range_included(&cur, range))
520 			continue;
521 		*range = cur;
522 		return 0;
523 	}
524 
525 	WARN_ON(1);
526 
527 	return -EINVAL;
528 }
529 
host_stage2_idmap_locked(phys_addr_t addr,u64 size,enum kvm_pgtable_prot prot)530 int host_stage2_idmap_locked(phys_addr_t addr, u64 size,
531 			     enum kvm_pgtable_prot prot)
532 {
533 	return host_stage2_try(__host_stage2_idmap, addr, addr + size, prot);
534 }
535 
__host_update_page_state(phys_addr_t addr,u64 size,enum pkvm_page_state state)536 static void __host_update_page_state(phys_addr_t addr, u64 size, enum pkvm_page_state state)
537 {
538 	for_each_hyp_page(page, addr, size)
539 		set_host_state(page, state);
540 }
541 
host_stage2_set_owner_locked(phys_addr_t addr,u64 size,u8 owner_id)542 int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id)
543 {
544 	int ret;
545 
546 	if (!range_is_memory(addr, addr + size))
547 		return -EPERM;
548 
549 	ret = host_stage2_try(kvm_pgtable_stage2_set_owner, &host_mmu.pgt,
550 			      addr, size, &host_s2_pool, owner_id);
551 	if (ret)
552 		return ret;
553 
554 	/* Don't forget to update the vmemmap tracking for the host */
555 	if (owner_id == PKVM_ID_HOST)
556 		__host_update_page_state(addr, size, PKVM_PAGE_OWNED);
557 	else
558 		__host_update_page_state(addr, size, PKVM_NOPAGE);
559 
560 	return 0;
561 }
562 
host_stage2_force_pte_cb(u64 addr,u64 end,enum kvm_pgtable_prot prot)563 static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot prot)
564 {
565 	/*
566 	 * Block mappings must be used with care in the host stage-2 as a
567 	 * kvm_pgtable_stage2_map() operation targeting a page in the range of
568 	 * an existing block will delete the block under the assumption that
569 	 * mappings in the rest of the block range can always be rebuilt lazily.
570 	 * That assumption is correct for the host stage-2 with RWX mappings
571 	 * targeting memory or RW mappings targeting MMIO ranges (see
572 	 * host_stage2_idmap() below which implements some of the host memory
573 	 * abort logic). However, this is not safe for any other mappings where
574 	 * the host stage-2 page-table is in fact the only place where this
575 	 * state is stored. In all those cases, it is safer to use page-level
576 	 * mappings, hence avoiding to lose the state because of side-effects in
577 	 * kvm_pgtable_stage2_map().
578 	 */
579 	if (range_is_memory(addr, end))
580 		return prot != PKVM_HOST_MEM_PROT;
581 	else
582 		return prot != PKVM_HOST_MMIO_PROT;
583 }
584 
host_stage2_idmap(u64 addr)585 static int host_stage2_idmap(u64 addr)
586 {
587 	struct kvm_mem_range range;
588 	bool is_memory = !!find_mem_range(addr, &range);
589 	enum kvm_pgtable_prot prot;
590 	int ret;
591 
592 	prot = is_memory ? PKVM_HOST_MEM_PROT : PKVM_HOST_MMIO_PROT;
593 
594 	host_lock_component();
595 	ret = host_stage2_adjust_range(addr, &range);
596 	if (ret)
597 		goto unlock;
598 
599 	ret = host_stage2_idmap_locked(range.start, range.end - range.start, prot);
600 unlock:
601 	host_unlock_component();
602 
603 	return ret;
604 }
605 
handle_host_mem_abort(struct kvm_cpu_context * host_ctxt)606 void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt)
607 {
608 	struct kvm_vcpu_fault_info fault;
609 	u64 esr, addr;
610 	int ret = 0;
611 
612 	esr = read_sysreg_el2(SYS_ESR);
613 	if (!__get_fault_info(esr, &fault)) {
614 		/*
615 		 * We've presumably raced with a page-table change which caused
616 		 * AT to fail, try again.
617 		 */
618 		return;
619 	}
620 
621 
622 	/*
623 	 * Yikes, we couldn't resolve the fault IPA. This should reinject an
624 	 * abort into the host when we figure out how to do that.
625 	 */
626 	BUG_ON(!(fault.hpfar_el2 & HPFAR_EL2_NS));
627 	addr = FIELD_GET(HPFAR_EL2_FIPA, fault.hpfar_el2) << 12;
628 
629 	ret = host_stage2_idmap(addr);
630 	BUG_ON(ret && ret != -EAGAIN);
631 }
632 
633 struct check_walk_data {
634 	enum pkvm_page_state	desired;
635 	enum pkvm_page_state	(*get_page_state)(kvm_pte_t pte, u64 addr);
636 };
637 
__check_page_state_visitor(const struct kvm_pgtable_visit_ctx * ctx,enum kvm_pgtable_walk_flags visit)638 static int __check_page_state_visitor(const struct kvm_pgtable_visit_ctx *ctx,
639 				      enum kvm_pgtable_walk_flags visit)
640 {
641 	struct check_walk_data *d = ctx->arg;
642 
643 	return d->get_page_state(ctx->old, ctx->addr) == d->desired ? 0 : -EPERM;
644 }
645 
check_page_state_range(struct kvm_pgtable * pgt,u64 addr,u64 size,struct check_walk_data * data)646 static int check_page_state_range(struct kvm_pgtable *pgt, u64 addr, u64 size,
647 				  struct check_walk_data *data)
648 {
649 	struct kvm_pgtable_walker walker = {
650 		.cb	= __check_page_state_visitor,
651 		.arg	= data,
652 		.flags	= KVM_PGTABLE_WALK_LEAF,
653 	};
654 
655 	return kvm_pgtable_walk(pgt, addr, size, &walker);
656 }
657 
__host_check_page_state_range(u64 addr,u64 size,enum pkvm_page_state state)658 static int __host_check_page_state_range(u64 addr, u64 size,
659 					 enum pkvm_page_state state)
660 {
661 	int ret;
662 
663 	ret = check_range_allowed_memory(addr, addr + size);
664 	if (ret)
665 		return ret;
666 
667 	hyp_assert_lock_held(&host_mmu.lock);
668 
669 	for_each_hyp_page(page, addr, size) {
670 		if (get_host_state(page) != state)
671 			return -EPERM;
672 	}
673 
674 	return 0;
675 }
676 
__host_set_page_state_range(u64 addr,u64 size,enum pkvm_page_state state)677 static int __host_set_page_state_range(u64 addr, u64 size,
678 				       enum pkvm_page_state state)
679 {
680 	if (get_host_state(hyp_phys_to_page(addr)) == PKVM_NOPAGE) {
681 		int ret = host_stage2_idmap_locked(addr, size, PKVM_HOST_MEM_PROT);
682 
683 		if (ret)
684 			return ret;
685 	}
686 
687 	__host_update_page_state(addr, size, state);
688 
689 	return 0;
690 }
691 
__hyp_set_page_state_range(phys_addr_t phys,u64 size,enum pkvm_page_state state)692 static void __hyp_set_page_state_range(phys_addr_t phys, u64 size, enum pkvm_page_state state)
693 {
694 	for_each_hyp_page(page, phys, size)
695 		set_hyp_state(page, state);
696 }
697 
__hyp_check_page_state_range(phys_addr_t phys,u64 size,enum pkvm_page_state state)698 static int __hyp_check_page_state_range(phys_addr_t phys, u64 size, enum pkvm_page_state state)
699 {
700 	for_each_hyp_page(page, phys, size) {
701 		if (get_hyp_state(page) != state)
702 			return -EPERM;
703 	}
704 
705 	return 0;
706 }
707 
guest_get_page_state(kvm_pte_t pte,u64 addr)708 static enum pkvm_page_state guest_get_page_state(kvm_pte_t pte, u64 addr)
709 {
710 	if (!kvm_pte_valid(pte))
711 		return PKVM_NOPAGE;
712 
713 	return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte));
714 }
715 
__guest_check_page_state_range(struct pkvm_hyp_vm * vm,u64 addr,u64 size,enum pkvm_page_state state)716 static int __guest_check_page_state_range(struct pkvm_hyp_vm *vm, u64 addr,
717 					  u64 size, enum pkvm_page_state state)
718 {
719 	struct check_walk_data d = {
720 		.desired	= state,
721 		.get_page_state	= guest_get_page_state,
722 	};
723 
724 	hyp_assert_lock_held(&vm->lock);
725 	return check_page_state_range(&vm->pgt, addr, size, &d);
726 }
727 
__pkvm_host_share_hyp(u64 pfn)728 int __pkvm_host_share_hyp(u64 pfn)
729 {
730 	u64 phys = hyp_pfn_to_phys(pfn);
731 	u64 size = PAGE_SIZE;
732 	int ret;
733 
734 	host_lock_component();
735 	hyp_lock_component();
736 
737 	ret = __host_check_page_state_range(phys, size, PKVM_PAGE_OWNED);
738 	if (ret)
739 		goto unlock;
740 	ret = __hyp_check_page_state_range(phys, size, PKVM_NOPAGE);
741 	if (ret)
742 		goto unlock;
743 
744 	__hyp_set_page_state_range(phys, size, PKVM_PAGE_SHARED_BORROWED);
745 	WARN_ON(__host_set_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED));
746 
747 unlock:
748 	hyp_unlock_component();
749 	host_unlock_component();
750 
751 	return ret;
752 }
753 
__pkvm_host_unshare_hyp(u64 pfn)754 int __pkvm_host_unshare_hyp(u64 pfn)
755 {
756 	u64 phys = hyp_pfn_to_phys(pfn);
757 	u64 virt = (u64)__hyp_va(phys);
758 	u64 size = PAGE_SIZE;
759 	int ret;
760 
761 	host_lock_component();
762 	hyp_lock_component();
763 
764 	ret = __host_check_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED);
765 	if (ret)
766 		goto unlock;
767 	ret = __hyp_check_page_state_range(phys, size, PKVM_PAGE_SHARED_BORROWED);
768 	if (ret)
769 		goto unlock;
770 	if (hyp_page_count((void *)virt)) {
771 		ret = -EBUSY;
772 		goto unlock;
773 	}
774 
775 	__hyp_set_page_state_range(phys, size, PKVM_NOPAGE);
776 	WARN_ON(__host_set_page_state_range(phys, size, PKVM_PAGE_OWNED));
777 
778 unlock:
779 	hyp_unlock_component();
780 	host_unlock_component();
781 
782 	return ret;
783 }
784 
__pkvm_host_donate_hyp(u64 pfn,u64 nr_pages)785 int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages)
786 {
787 	u64 phys = hyp_pfn_to_phys(pfn);
788 	u64 size = PAGE_SIZE * nr_pages;
789 	void *virt = __hyp_va(phys);
790 	int ret;
791 
792 	if (!pfn_range_is_valid(pfn, nr_pages))
793 		return -EINVAL;
794 
795 	host_lock_component();
796 	hyp_lock_component();
797 
798 	ret = __host_check_page_state_range(phys, size, PKVM_PAGE_OWNED);
799 	if (ret)
800 		goto unlock;
801 	ret = __hyp_check_page_state_range(phys, size, PKVM_NOPAGE);
802 	if (ret)
803 		goto unlock;
804 
805 	__hyp_set_page_state_range(phys, size, PKVM_PAGE_OWNED);
806 	WARN_ON(pkvm_create_mappings_locked(virt, virt + size, PAGE_HYP));
807 	WARN_ON(host_stage2_set_owner_locked(phys, size, PKVM_ID_HYP));
808 
809 unlock:
810 	hyp_unlock_component();
811 	host_unlock_component();
812 
813 	return ret;
814 }
815 
__pkvm_hyp_donate_host(u64 pfn,u64 nr_pages)816 int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages)
817 {
818 	u64 phys = hyp_pfn_to_phys(pfn);
819 	u64 size = PAGE_SIZE * nr_pages;
820 	u64 virt = (u64)__hyp_va(phys);
821 	int ret;
822 
823 	if (!pfn_range_is_valid(pfn, nr_pages))
824 		return -EINVAL;
825 
826 	host_lock_component();
827 	hyp_lock_component();
828 
829 	ret = __hyp_check_page_state_range(phys, size, PKVM_PAGE_OWNED);
830 	if (ret)
831 		goto unlock;
832 	ret = __host_check_page_state_range(phys, size, PKVM_NOPAGE);
833 	if (ret)
834 		goto unlock;
835 
836 	__hyp_set_page_state_range(phys, size, PKVM_NOPAGE);
837 	WARN_ON(kvm_pgtable_hyp_unmap(&pkvm_pgtable, virt, size) != size);
838 	WARN_ON(host_stage2_set_owner_locked(phys, size, PKVM_ID_HOST));
839 
840 unlock:
841 	hyp_unlock_component();
842 	host_unlock_component();
843 
844 	return ret;
845 }
846 
hyp_pin_shared_mem(void * from,void * to)847 int hyp_pin_shared_mem(void *from, void *to)
848 {
849 	u64 cur, start = ALIGN_DOWN((u64)from, PAGE_SIZE);
850 	u64 end = PAGE_ALIGN((u64)to);
851 	u64 phys = __hyp_pa(start);
852 	u64 size = end - start;
853 	struct hyp_page *p;
854 	int ret;
855 
856 	host_lock_component();
857 	hyp_lock_component();
858 
859 	ret = __host_check_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED);
860 	if (ret)
861 		goto unlock;
862 
863 	ret = __hyp_check_page_state_range(phys, size, PKVM_PAGE_SHARED_BORROWED);
864 	if (ret)
865 		goto unlock;
866 
867 	for (cur = start; cur < end; cur += PAGE_SIZE) {
868 		p = hyp_virt_to_page(cur);
869 		hyp_page_ref_inc(p);
870 		if (p->refcount == 1)
871 			WARN_ON(pkvm_create_mappings_locked((void *)cur,
872 							    (void *)cur + PAGE_SIZE,
873 							    PAGE_HYP));
874 	}
875 
876 unlock:
877 	hyp_unlock_component();
878 	host_unlock_component();
879 
880 	return ret;
881 }
882 
hyp_unpin_shared_mem(void * from,void * to)883 void hyp_unpin_shared_mem(void *from, void *to)
884 {
885 	u64 cur, start = ALIGN_DOWN((u64)from, PAGE_SIZE);
886 	u64 end = PAGE_ALIGN((u64)to);
887 	struct hyp_page *p;
888 
889 	host_lock_component();
890 	hyp_lock_component();
891 
892 	for (cur = start; cur < end; cur += PAGE_SIZE) {
893 		p = hyp_virt_to_page(cur);
894 		if (p->refcount == 1)
895 			WARN_ON(kvm_pgtable_hyp_unmap(&pkvm_pgtable, cur, PAGE_SIZE) != PAGE_SIZE);
896 		hyp_page_ref_dec(p);
897 	}
898 
899 	hyp_unlock_component();
900 	host_unlock_component();
901 }
902 
__pkvm_host_share_ffa(u64 pfn,u64 nr_pages)903 int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages)
904 {
905 	u64 phys = hyp_pfn_to_phys(pfn);
906 	u64 size = PAGE_SIZE * nr_pages;
907 	int ret;
908 
909 	if (!pfn_range_is_valid(pfn, nr_pages))
910 		return -EINVAL;
911 
912 	host_lock_component();
913 	ret = __host_check_page_state_range(phys, size, PKVM_PAGE_OWNED);
914 	if (!ret)
915 		ret = __host_set_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED);
916 	host_unlock_component();
917 
918 	return ret;
919 }
920 
__pkvm_host_unshare_ffa(u64 pfn,u64 nr_pages)921 int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages)
922 {
923 	u64 phys = hyp_pfn_to_phys(pfn);
924 	u64 size = PAGE_SIZE * nr_pages;
925 	int ret;
926 
927 	if (!pfn_range_is_valid(pfn, nr_pages))
928 		return -EINVAL;
929 
930 	host_lock_component();
931 	ret = __host_check_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED);
932 	if (!ret)
933 		ret = __host_set_page_state_range(phys, size, PKVM_PAGE_OWNED);
934 	host_unlock_component();
935 
936 	return ret;
937 }
938 
__guest_check_transition_size(u64 phys,u64 ipa,u64 nr_pages,u64 * size)939 static int __guest_check_transition_size(u64 phys, u64 ipa, u64 nr_pages, u64 *size)
940 {
941 	size_t block_size;
942 
943 	if (nr_pages == 1) {
944 		*size = PAGE_SIZE;
945 		return 0;
946 	}
947 
948 	/* We solely support second to last level huge mapping */
949 	block_size = kvm_granule_size(KVM_PGTABLE_LAST_LEVEL - 1);
950 
951 	if (nr_pages != block_size >> PAGE_SHIFT)
952 		return -EINVAL;
953 
954 	if (!IS_ALIGNED(phys | ipa, block_size))
955 		return -EINVAL;
956 
957 	*size = block_size;
958 	return 0;
959 }
960 
__pkvm_host_share_guest(u64 pfn,u64 gfn,u64 nr_pages,struct pkvm_hyp_vcpu * vcpu,enum kvm_pgtable_prot prot)961 int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu,
962 			    enum kvm_pgtable_prot prot)
963 {
964 	struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
965 	u64 phys = hyp_pfn_to_phys(pfn);
966 	u64 ipa = hyp_pfn_to_phys(gfn);
967 	u64 size;
968 	int ret;
969 
970 	if (prot & ~KVM_PGTABLE_PROT_RWX)
971 		return -EINVAL;
972 
973 	if (!pfn_range_is_valid(pfn, nr_pages))
974 		return -EINVAL;
975 
976 	ret = __guest_check_transition_size(phys, ipa, nr_pages, &size);
977 	if (ret)
978 		return ret;
979 
980 	ret = check_range_allowed_memory(phys, phys + size);
981 	if (ret)
982 		return ret;
983 
984 	host_lock_component();
985 	guest_lock_component(vm);
986 
987 	ret = __guest_check_page_state_range(vm, ipa, size, PKVM_NOPAGE);
988 	if (ret)
989 		goto unlock;
990 
991 	for_each_hyp_page(page, phys, size) {
992 		switch (get_host_state(page)) {
993 		case PKVM_PAGE_OWNED:
994 			continue;
995 		case PKVM_PAGE_SHARED_OWNED:
996 			if (page->host_share_guest_count == U32_MAX) {
997 				ret = -EBUSY;
998 				goto unlock;
999 			}
1000 
1001 			/* Only host to np-guest multi-sharing is tolerated */
1002 			if (page->host_share_guest_count)
1003 				continue;
1004 
1005 			fallthrough;
1006 		default:
1007 			ret = -EPERM;
1008 			goto unlock;
1009 		}
1010 	}
1011 
1012 	for_each_hyp_page(page, phys, size) {
1013 		set_host_state(page, PKVM_PAGE_SHARED_OWNED);
1014 		page->host_share_guest_count++;
1015 	}
1016 
1017 	WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, size, phys,
1018 				       pkvm_mkstate(prot, PKVM_PAGE_SHARED_BORROWED),
1019 				       &vcpu->vcpu.arch.pkvm_memcache, 0));
1020 
1021 unlock:
1022 	guest_unlock_component(vm);
1023 	host_unlock_component();
1024 
1025 	return ret;
1026 }
1027 
__check_host_shared_guest(struct pkvm_hyp_vm * vm,u64 * __phys,u64 ipa,u64 size)1028 static int __check_host_shared_guest(struct pkvm_hyp_vm *vm, u64 *__phys, u64 ipa, u64 size)
1029 {
1030 	enum pkvm_page_state state;
1031 	kvm_pte_t pte;
1032 	u64 phys;
1033 	s8 level;
1034 	int ret;
1035 
1036 	ret = kvm_pgtable_get_leaf(&vm->pgt, ipa, &pte, &level);
1037 	if (ret)
1038 		return ret;
1039 	if (!kvm_pte_valid(pte))
1040 		return -ENOENT;
1041 	if (size && kvm_granule_size(level) != size)
1042 		return -E2BIG;
1043 
1044 	if (!size)
1045 		size = kvm_granule_size(level);
1046 
1047 	state = guest_get_page_state(pte, ipa);
1048 	if (state != PKVM_PAGE_SHARED_BORROWED)
1049 		return -EPERM;
1050 
1051 	phys = kvm_pte_to_phys(pte);
1052 	ret = check_range_allowed_memory(phys, phys + size);
1053 	if (WARN_ON(ret))
1054 		return ret;
1055 
1056 	for_each_hyp_page(page, phys, size) {
1057 		if (get_host_state(page) != PKVM_PAGE_SHARED_OWNED)
1058 			return -EPERM;
1059 		if (WARN_ON(!page->host_share_guest_count))
1060 			return -EINVAL;
1061 	}
1062 
1063 	*__phys = phys;
1064 
1065 	return 0;
1066 }
1067 
__pkvm_host_unshare_guest(u64 gfn,u64 nr_pages,struct pkvm_hyp_vm * vm)1068 int __pkvm_host_unshare_guest(u64 gfn, u64 nr_pages, struct pkvm_hyp_vm *vm)
1069 {
1070 	u64 ipa = hyp_pfn_to_phys(gfn);
1071 	u64 size, phys;
1072 	int ret;
1073 
1074 	ret = __guest_check_transition_size(0, ipa, nr_pages, &size);
1075 	if (ret)
1076 		return ret;
1077 
1078 	host_lock_component();
1079 	guest_lock_component(vm);
1080 
1081 	ret = __check_host_shared_guest(vm, &phys, ipa, size);
1082 	if (ret)
1083 		goto unlock;
1084 
1085 	ret = kvm_pgtable_stage2_unmap(&vm->pgt, ipa, size);
1086 	if (ret)
1087 		goto unlock;
1088 
1089 	for_each_hyp_page(page, phys, size) {
1090 		/* __check_host_shared_guest() protects against underflow */
1091 		page->host_share_guest_count--;
1092 		if (!page->host_share_guest_count)
1093 			set_host_state(page, PKVM_PAGE_OWNED);
1094 	}
1095 
1096 unlock:
1097 	guest_unlock_component(vm);
1098 	host_unlock_component();
1099 
1100 	return ret;
1101 }
1102 
assert_host_shared_guest(struct pkvm_hyp_vm * vm,u64 ipa,u64 size)1103 static void assert_host_shared_guest(struct pkvm_hyp_vm *vm, u64 ipa, u64 size)
1104 {
1105 	u64 phys;
1106 	int ret;
1107 
1108 	if (!IS_ENABLED(CONFIG_NVHE_EL2_DEBUG))
1109 		return;
1110 
1111 	host_lock_component();
1112 	guest_lock_component(vm);
1113 
1114 	ret = __check_host_shared_guest(vm, &phys, ipa, size);
1115 
1116 	guest_unlock_component(vm);
1117 	host_unlock_component();
1118 
1119 	WARN_ON(ret && ret != -ENOENT);
1120 }
1121 
__pkvm_host_relax_perms_guest(u64 gfn,struct pkvm_hyp_vcpu * vcpu,enum kvm_pgtable_prot prot)1122 int __pkvm_host_relax_perms_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu, enum kvm_pgtable_prot prot)
1123 {
1124 	struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
1125 	u64 ipa = hyp_pfn_to_phys(gfn);
1126 	int ret;
1127 
1128 	if (pkvm_hyp_vm_is_protected(vm))
1129 		return -EPERM;
1130 
1131 	if (prot & ~KVM_PGTABLE_PROT_RWX)
1132 		return -EINVAL;
1133 
1134 	assert_host_shared_guest(vm, ipa, 0);
1135 	guest_lock_component(vm);
1136 	ret = kvm_pgtable_stage2_relax_perms(&vm->pgt, ipa, prot, 0);
1137 	guest_unlock_component(vm);
1138 
1139 	return ret;
1140 }
1141 
__pkvm_host_wrprotect_guest(u64 gfn,u64 nr_pages,struct pkvm_hyp_vm * vm)1142 int __pkvm_host_wrprotect_guest(u64 gfn, u64 nr_pages, struct pkvm_hyp_vm *vm)
1143 {
1144 	u64 size, ipa = hyp_pfn_to_phys(gfn);
1145 	int ret;
1146 
1147 	if (pkvm_hyp_vm_is_protected(vm))
1148 		return -EPERM;
1149 
1150 	ret = __guest_check_transition_size(0, ipa, nr_pages, &size);
1151 	if (ret)
1152 		return ret;
1153 
1154 	assert_host_shared_guest(vm, ipa, size);
1155 	guest_lock_component(vm);
1156 	ret = kvm_pgtable_stage2_wrprotect(&vm->pgt, ipa, size);
1157 	guest_unlock_component(vm);
1158 
1159 	return ret;
1160 }
1161 
__pkvm_host_test_clear_young_guest(u64 gfn,u64 nr_pages,bool mkold,struct pkvm_hyp_vm * vm)1162 int __pkvm_host_test_clear_young_guest(u64 gfn, u64 nr_pages, bool mkold, struct pkvm_hyp_vm *vm)
1163 {
1164 	u64 size, ipa = hyp_pfn_to_phys(gfn);
1165 	int ret;
1166 
1167 	if (pkvm_hyp_vm_is_protected(vm))
1168 		return -EPERM;
1169 
1170 	ret = __guest_check_transition_size(0, ipa, nr_pages, &size);
1171 	if (ret)
1172 		return ret;
1173 
1174 	assert_host_shared_guest(vm, ipa, size);
1175 	guest_lock_component(vm);
1176 	ret = kvm_pgtable_stage2_test_clear_young(&vm->pgt, ipa, size, mkold);
1177 	guest_unlock_component(vm);
1178 
1179 	return ret;
1180 }
1181 
__pkvm_host_mkyoung_guest(u64 gfn,struct pkvm_hyp_vcpu * vcpu)1182 int __pkvm_host_mkyoung_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu)
1183 {
1184 	struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
1185 	u64 ipa = hyp_pfn_to_phys(gfn);
1186 
1187 	if (pkvm_hyp_vm_is_protected(vm))
1188 		return -EPERM;
1189 
1190 	assert_host_shared_guest(vm, ipa, 0);
1191 	guest_lock_component(vm);
1192 	kvm_pgtable_stage2_mkyoung(&vm->pgt, ipa, 0);
1193 	guest_unlock_component(vm);
1194 
1195 	return 0;
1196 }
1197 
1198 #ifdef CONFIG_NVHE_EL2_DEBUG
1199 struct pkvm_expected_state {
1200 	enum pkvm_page_state host;
1201 	enum pkvm_page_state hyp;
1202 	enum pkvm_page_state guest[2]; /* [ gfn, gfn + 1 ] */
1203 };
1204 
1205 static struct pkvm_expected_state selftest_state;
1206 static struct hyp_page *selftest_page;
1207 
1208 static struct pkvm_hyp_vm selftest_vm = {
1209 	.kvm = {
1210 		.arch = {
1211 			.mmu = {
1212 				.arch = &selftest_vm.kvm.arch,
1213 				.pgt = &selftest_vm.pgt,
1214 			},
1215 		},
1216 	},
1217 };
1218 
1219 static struct pkvm_hyp_vcpu selftest_vcpu = {
1220 	.vcpu = {
1221 		.arch = {
1222 			.hw_mmu = &selftest_vm.kvm.arch.mmu,
1223 		},
1224 		.kvm = &selftest_vm.kvm,
1225 	},
1226 };
1227 
init_selftest_vm(void * virt)1228 static void init_selftest_vm(void *virt)
1229 {
1230 	struct hyp_page *p = hyp_virt_to_page(virt);
1231 	int i;
1232 
1233 	selftest_vm.kvm.arch.mmu.vtcr = host_mmu.arch.mmu.vtcr;
1234 	WARN_ON(kvm_guest_prepare_stage2(&selftest_vm, virt));
1235 
1236 	for (i = 0; i < pkvm_selftest_pages(); i++) {
1237 		if (p[i].refcount)
1238 			continue;
1239 		p[i].refcount = 1;
1240 		hyp_put_page(&selftest_vm.pool, hyp_page_to_virt(&p[i]));
1241 	}
1242 }
1243 
selftest_ipa(void)1244 static u64 selftest_ipa(void)
1245 {
1246 	return BIT(selftest_vm.pgt.ia_bits - 1);
1247 }
1248 
assert_page_state(void)1249 static void assert_page_state(void)
1250 {
1251 	void *virt = hyp_page_to_virt(selftest_page);
1252 	u64 size = PAGE_SIZE << selftest_page->order;
1253 	struct pkvm_hyp_vcpu *vcpu = &selftest_vcpu;
1254 	u64 phys = hyp_virt_to_phys(virt);
1255 	u64 ipa[2] = { selftest_ipa(), selftest_ipa() + PAGE_SIZE };
1256 	struct pkvm_hyp_vm *vm;
1257 
1258 	vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
1259 
1260 	host_lock_component();
1261 	WARN_ON(__host_check_page_state_range(phys, size, selftest_state.host));
1262 	host_unlock_component();
1263 
1264 	hyp_lock_component();
1265 	WARN_ON(__hyp_check_page_state_range(phys, size, selftest_state.hyp));
1266 	hyp_unlock_component();
1267 
1268 	guest_lock_component(&selftest_vm);
1269 	WARN_ON(__guest_check_page_state_range(vm, ipa[0], size, selftest_state.guest[0]));
1270 	WARN_ON(__guest_check_page_state_range(vm, ipa[1], size, selftest_state.guest[1]));
1271 	guest_unlock_component(&selftest_vm);
1272 }
1273 
1274 #define assert_transition_res(res, fn, ...)		\
1275 	do {						\
1276 		WARN_ON(fn(__VA_ARGS__) != res);	\
1277 		assert_page_state();			\
1278 	} while (0)
1279 
pkvm_ownership_selftest(void * base)1280 void pkvm_ownership_selftest(void *base)
1281 {
1282 	enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_RWX;
1283 	void *virt = hyp_alloc_pages(&host_s2_pool, 0);
1284 	struct pkvm_hyp_vcpu *vcpu = &selftest_vcpu;
1285 	struct pkvm_hyp_vm *vm = &selftest_vm;
1286 	u64 phys, size, pfn, gfn;
1287 
1288 	WARN_ON(!virt);
1289 	selftest_page = hyp_virt_to_page(virt);
1290 	selftest_page->refcount = 0;
1291 	init_selftest_vm(base);
1292 
1293 	size = PAGE_SIZE << selftest_page->order;
1294 	phys = hyp_virt_to_phys(virt);
1295 	pfn = hyp_phys_to_pfn(phys);
1296 	gfn = hyp_phys_to_pfn(selftest_ipa());
1297 
1298 	selftest_state.host = PKVM_NOPAGE;
1299 	selftest_state.hyp = PKVM_PAGE_OWNED;
1300 	selftest_state.guest[0] = selftest_state.guest[1] = PKVM_NOPAGE;
1301 	assert_page_state();
1302 	assert_transition_res(-EPERM,	__pkvm_host_donate_hyp, pfn, 1);
1303 	assert_transition_res(-EPERM,	__pkvm_host_share_hyp, pfn);
1304 	assert_transition_res(-EPERM,	__pkvm_host_unshare_hyp, pfn);
1305 	assert_transition_res(-EPERM,	__pkvm_host_share_ffa, pfn, 1);
1306 	assert_transition_res(-EPERM,	__pkvm_host_unshare_ffa, pfn, 1);
1307 	assert_transition_res(-EPERM,	hyp_pin_shared_mem, virt, virt + size);
1308 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
1309 	assert_transition_res(-ENOENT,	__pkvm_host_unshare_guest, gfn, 1, vm);
1310 
1311 	selftest_state.host = PKVM_PAGE_OWNED;
1312 	selftest_state.hyp = PKVM_NOPAGE;
1313 	assert_transition_res(0,	__pkvm_hyp_donate_host, pfn, 1);
1314 	assert_transition_res(-EPERM,	__pkvm_hyp_donate_host, pfn, 1);
1315 	assert_transition_res(-EPERM,	__pkvm_host_unshare_hyp, pfn);
1316 	assert_transition_res(-EPERM,	__pkvm_host_unshare_ffa, pfn, 1);
1317 	assert_transition_res(-ENOENT,	__pkvm_host_unshare_guest, gfn, 1, vm);
1318 	assert_transition_res(-EPERM,	hyp_pin_shared_mem, virt, virt + size);
1319 
1320 	selftest_state.host = PKVM_PAGE_SHARED_OWNED;
1321 	selftest_state.hyp = PKVM_PAGE_SHARED_BORROWED;
1322 	assert_transition_res(0,	__pkvm_host_share_hyp, pfn);
1323 	assert_transition_res(-EPERM,	__pkvm_host_share_hyp, pfn);
1324 	assert_transition_res(-EPERM,	__pkvm_host_donate_hyp, pfn, 1);
1325 	assert_transition_res(-EPERM,	__pkvm_host_share_ffa, pfn, 1);
1326 	assert_transition_res(-EPERM,	__pkvm_hyp_donate_host, pfn, 1);
1327 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
1328 	assert_transition_res(-ENOENT,	__pkvm_host_unshare_guest, gfn, 1, vm);
1329 
1330 	assert_transition_res(0,	hyp_pin_shared_mem, virt, virt + size);
1331 	assert_transition_res(0,	hyp_pin_shared_mem, virt, virt + size);
1332 	hyp_unpin_shared_mem(virt, virt + size);
1333 	WARN_ON(hyp_page_count(virt) != 1);
1334 	assert_transition_res(-EBUSY,	__pkvm_host_unshare_hyp, pfn);
1335 	assert_transition_res(-EPERM,	__pkvm_host_share_hyp, pfn);
1336 	assert_transition_res(-EPERM,	__pkvm_host_donate_hyp, pfn, 1);
1337 	assert_transition_res(-EPERM,	__pkvm_host_share_ffa, pfn, 1);
1338 	assert_transition_res(-EPERM,	__pkvm_hyp_donate_host, pfn, 1);
1339 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
1340 	assert_transition_res(-ENOENT,	__pkvm_host_unshare_guest, gfn, 1, vm);
1341 
1342 	hyp_unpin_shared_mem(virt, virt + size);
1343 	assert_page_state();
1344 	WARN_ON(hyp_page_count(virt));
1345 
1346 	selftest_state.host = PKVM_PAGE_OWNED;
1347 	selftest_state.hyp = PKVM_NOPAGE;
1348 	assert_transition_res(0,	__pkvm_host_unshare_hyp, pfn);
1349 
1350 	selftest_state.host = PKVM_PAGE_SHARED_OWNED;
1351 	selftest_state.hyp = PKVM_NOPAGE;
1352 	assert_transition_res(0,	__pkvm_host_share_ffa, pfn, 1);
1353 	assert_transition_res(-EPERM,	__pkvm_host_share_ffa, pfn, 1);
1354 	assert_transition_res(-EPERM,	__pkvm_host_donate_hyp, pfn, 1);
1355 	assert_transition_res(-EPERM,	__pkvm_host_share_hyp, pfn);
1356 	assert_transition_res(-EPERM,	__pkvm_host_unshare_hyp, pfn);
1357 	assert_transition_res(-EPERM,	__pkvm_hyp_donate_host, pfn, 1);
1358 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
1359 	assert_transition_res(-ENOENT,	__pkvm_host_unshare_guest, gfn, 1, vm);
1360 	assert_transition_res(-EPERM,	hyp_pin_shared_mem, virt, virt + size);
1361 
1362 	selftest_state.host = PKVM_PAGE_OWNED;
1363 	selftest_state.hyp = PKVM_NOPAGE;
1364 	assert_transition_res(0,	__pkvm_host_unshare_ffa, pfn, 1);
1365 	assert_transition_res(-EPERM,	__pkvm_host_unshare_ffa, pfn, 1);
1366 
1367 	selftest_state.host = PKVM_PAGE_SHARED_OWNED;
1368 	selftest_state.guest[0] = PKVM_PAGE_SHARED_BORROWED;
1369 	assert_transition_res(0,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
1370 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
1371 	assert_transition_res(-EPERM,	__pkvm_host_share_ffa, pfn, 1);
1372 	assert_transition_res(-EPERM,	__pkvm_host_donate_hyp, pfn, 1);
1373 	assert_transition_res(-EPERM,	__pkvm_host_share_hyp, pfn);
1374 	assert_transition_res(-EPERM,	__pkvm_host_unshare_hyp, pfn);
1375 	assert_transition_res(-EPERM,	__pkvm_hyp_donate_host, pfn, 1);
1376 	assert_transition_res(-EPERM,	hyp_pin_shared_mem, virt, virt + size);
1377 
1378 	selftest_state.guest[1] = PKVM_PAGE_SHARED_BORROWED;
1379 	assert_transition_res(0,	__pkvm_host_share_guest, pfn, gfn + 1, 1, vcpu, prot);
1380 	WARN_ON(hyp_virt_to_page(virt)->host_share_guest_count != 2);
1381 
1382 	selftest_state.guest[0] = PKVM_NOPAGE;
1383 	assert_transition_res(0,	__pkvm_host_unshare_guest, gfn, 1, vm);
1384 
1385 	selftest_state.guest[1] = PKVM_NOPAGE;
1386 	selftest_state.host = PKVM_PAGE_OWNED;
1387 	assert_transition_res(0,	__pkvm_host_unshare_guest, gfn + 1, 1, vm);
1388 
1389 	selftest_state.host = PKVM_NOPAGE;
1390 	selftest_state.hyp = PKVM_PAGE_OWNED;
1391 	assert_transition_res(0,	__pkvm_host_donate_hyp, pfn, 1);
1392 
1393 	selftest_page->refcount = 1;
1394 	hyp_put_page(&host_s2_pool, virt);
1395 }
1396 #endif
1397