1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
4 *
5 * Authors:
6 *     Anup Patel <anup.patel@wdc.com>
7 */
8
9#include <linux/bitops.h>
10#include <linux/errno.h>
11#include <linux/err.h>
12#include <linux/hugetlb.h>
13#include <linux/module.h>
14#include <linux/uaccess.h>
15#include <linux/vmalloc.h>
16#include <linux/kvm_host.h>
17#include <linux/sched/signal.h>
18#include <asm/csr.h>
19#include <asm/page.h>
20#include <asm/pgtable.h>
21
22#ifdef CONFIG_64BIT
23static unsigned long gstage_mode __ro_after_init = (HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT);
24static unsigned long gstage_pgd_levels __ro_after_init = 3;
25#define gstage_index_bits	9
26#else
27static unsigned long gstage_mode __ro_after_init = (HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT);
28static unsigned long gstage_pgd_levels __ro_after_init = 2;
29#define gstage_index_bits	10
30#endif
31
32#define gstage_pgd_xbits	2
33#define gstage_pgd_size	(1UL << (HGATP_PAGE_SHIFT + gstage_pgd_xbits))
34#define gstage_gpa_bits	(HGATP_PAGE_SHIFT + \
35			 (gstage_pgd_levels * gstage_index_bits) + \
36			 gstage_pgd_xbits)
37#define gstage_gpa_size	((gpa_t)(1ULL << gstage_gpa_bits))
38
39#define gstage_pte_leaf(__ptep)	\
40	(pte_val(*(__ptep)) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC))
41
42static inline unsigned long gstage_pte_index(gpa_t addr, u32 level)
43{
44	unsigned long mask;
45	unsigned long shift = HGATP_PAGE_SHIFT + (gstage_index_bits * level);
46
47	if (level == (gstage_pgd_levels - 1))
48		mask = (PTRS_PER_PTE * (1UL << gstage_pgd_xbits)) - 1;
49	else
50		mask = PTRS_PER_PTE - 1;
51
52	return (addr >> shift) & mask;
53}
54
55static inline unsigned long gstage_pte_page_vaddr(pte_t pte)
56{
57	return (unsigned long)pfn_to_virt(__page_val_to_pfn(pte_val(pte)));
58}
59
60static int gstage_page_size_to_level(unsigned long page_size, u32 *out_level)
61{
62	u32 i;
63	unsigned long psz = 1UL << 12;
64
65	for (i = 0; i < gstage_pgd_levels; i++) {
66		if (page_size == (psz << (i * gstage_index_bits))) {
67			*out_level = i;
68			return 0;
69		}
70	}
71
72	return -EINVAL;
73}
74
75static int gstage_level_to_page_order(u32 level, unsigned long *out_pgorder)
76{
77	if (gstage_pgd_levels < level)
78		return -EINVAL;
79
80	*out_pgorder = 12 + (level * gstage_index_bits);
81	return 0;
82}
83
84static int gstage_level_to_page_size(u32 level, unsigned long *out_pgsize)
85{
86	int rc;
87	unsigned long page_order = PAGE_SHIFT;
88
89	rc = gstage_level_to_page_order(level, &page_order);
90	if (rc)
91		return rc;
92
93	*out_pgsize = BIT(page_order);
94	return 0;
95}
96
97static bool gstage_get_leaf_entry(struct kvm *kvm, gpa_t addr,
98				  pte_t **ptepp, u32 *ptep_level)
99{
100	pte_t *ptep;
101	u32 current_level = gstage_pgd_levels - 1;
102
103	*ptep_level = current_level;
104	ptep = (pte_t *)kvm->arch.pgd;
105	ptep = &ptep[gstage_pte_index(addr, current_level)];
106	while (ptep && pte_val(ptep_get(ptep))) {
107		if (gstage_pte_leaf(ptep)) {
108			*ptep_level = current_level;
109			*ptepp = ptep;
110			return true;
111		}
112
113		if (current_level) {
114			current_level--;
115			*ptep_level = current_level;
116			ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
117			ptep = &ptep[gstage_pte_index(addr, current_level)];
118		} else {
119			ptep = NULL;
120		}
121	}
122
123	return false;
124}
125
126static void gstage_remote_tlb_flush(struct kvm *kvm, u32 level, gpa_t addr)
127{
128	unsigned long order = PAGE_SHIFT;
129
130	if (gstage_level_to_page_order(level, &order))
131		return;
132	addr &= ~(BIT(order) - 1);
133
134	kvm_riscv_hfence_gvma_vmid_gpa(kvm, -1UL, 0, addr, BIT(order), order);
135}
136
137static int gstage_set_pte(struct kvm *kvm, u32 level,
138			   struct kvm_mmu_memory_cache *pcache,
139			   gpa_t addr, const pte_t *new_pte)
140{
141	u32 current_level = gstage_pgd_levels - 1;
142	pte_t *next_ptep = (pte_t *)kvm->arch.pgd;
143	pte_t *ptep = &next_ptep[gstage_pte_index(addr, current_level)];
144
145	if (current_level < level)
146		return -EINVAL;
147
148	while (current_level != level) {
149		if (gstage_pte_leaf(ptep))
150			return -EEXIST;
151
152		if (!pte_val(ptep_get(ptep))) {
153			if (!pcache)
154				return -ENOMEM;
155			next_ptep = kvm_mmu_memory_cache_alloc(pcache);
156			if (!next_ptep)
157				return -ENOMEM;
158			set_pte(ptep, pfn_pte(PFN_DOWN(__pa(next_ptep)),
159					      __pgprot(_PAGE_TABLE)));
160		} else {
161			if (gstage_pte_leaf(ptep))
162				return -EEXIST;
163			next_ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
164		}
165
166		current_level--;
167		ptep = &next_ptep[gstage_pte_index(addr, current_level)];
168	}
169
170	set_pte(ptep, *new_pte);
171	if (gstage_pte_leaf(ptep))
172		gstage_remote_tlb_flush(kvm, current_level, addr);
173
174	return 0;
175}
176
177static int gstage_map_page(struct kvm *kvm,
178			   struct kvm_mmu_memory_cache *pcache,
179			   gpa_t gpa, phys_addr_t hpa,
180			   unsigned long page_size,
181			   bool page_rdonly, bool page_exec)
182{
183	int ret;
184	u32 level = 0;
185	pte_t new_pte;
186	pgprot_t prot;
187
188	ret = gstage_page_size_to_level(page_size, &level);
189	if (ret)
190		return ret;
191
192	/*
193	 * A RISC-V implementation can choose to either:
194	 * 1) Update 'A' and 'D' PTE bits in hardware
195	 * 2) Generate page fault when 'A' and/or 'D' bits are not set
196	 *    PTE so that software can update these bits.
197	 *
198	 * We support both options mentioned above. To achieve this, we
199	 * always set 'A' and 'D' PTE bits at time of creating G-stage
200	 * mapping. To support KVM dirty page logging with both options
201	 * mentioned above, we will write-protect G-stage PTEs to track
202	 * dirty pages.
203	 */
204
205	if (page_exec) {
206		if (page_rdonly)
207			prot = PAGE_READ_EXEC;
208		else
209			prot = PAGE_WRITE_EXEC;
210	} else {
211		if (page_rdonly)
212			prot = PAGE_READ;
213		else
214			prot = PAGE_WRITE;
215	}
216	new_pte = pfn_pte(PFN_DOWN(hpa), prot);
217	new_pte = pte_mkdirty(new_pte);
218
219	return gstage_set_pte(kvm, level, pcache, gpa, &new_pte);
220}
221
222enum gstage_op {
223	GSTAGE_OP_NOP = 0,	/* Nothing */
224	GSTAGE_OP_CLEAR,	/* Clear/Unmap */
225	GSTAGE_OP_WP,		/* Write-protect */
226};
227
228static void gstage_op_pte(struct kvm *kvm, gpa_t addr,
229			  pte_t *ptep, u32 ptep_level, enum gstage_op op)
230{
231	int i, ret;
232	pte_t *next_ptep;
233	u32 next_ptep_level;
234	unsigned long next_page_size, page_size;
235
236	ret = gstage_level_to_page_size(ptep_level, &page_size);
237	if (ret)
238		return;
239
240	BUG_ON(addr & (page_size - 1));
241
242	if (!pte_val(ptep_get(ptep)))
243		return;
244
245	if (ptep_level && !gstage_pte_leaf(ptep)) {
246		next_ptep = (pte_t *)gstage_pte_page_vaddr(ptep_get(ptep));
247		next_ptep_level = ptep_level - 1;
248		ret = gstage_level_to_page_size(next_ptep_level,
249						&next_page_size);
250		if (ret)
251			return;
252
253		if (op == GSTAGE_OP_CLEAR)
254			set_pte(ptep, __pte(0));
255		for (i = 0; i < PTRS_PER_PTE; i++)
256			gstage_op_pte(kvm, addr + i * next_page_size,
257					&next_ptep[i], next_ptep_level, op);
258		if (op == GSTAGE_OP_CLEAR)
259			put_page(virt_to_page(next_ptep));
260	} else {
261		if (op == GSTAGE_OP_CLEAR)
262			set_pte(ptep, __pte(0));
263		else if (op == GSTAGE_OP_WP)
264			set_pte(ptep, __pte(pte_val(ptep_get(ptep)) & ~_PAGE_WRITE));
265		gstage_remote_tlb_flush(kvm, ptep_level, addr);
266	}
267}
268
269static void gstage_unmap_range(struct kvm *kvm, gpa_t start,
270			       gpa_t size, bool may_block)
271{
272	int ret;
273	pte_t *ptep;
274	u32 ptep_level;
275	bool found_leaf;
276	unsigned long page_size;
277	gpa_t addr = start, end = start + size;
278
279	while (addr < end) {
280		found_leaf = gstage_get_leaf_entry(kvm, addr,
281						   &ptep, &ptep_level);
282		ret = gstage_level_to_page_size(ptep_level, &page_size);
283		if (ret)
284			break;
285
286		if (!found_leaf)
287			goto next;
288
289		if (!(addr & (page_size - 1)) && ((end - addr) >= page_size))
290			gstage_op_pte(kvm, addr, ptep,
291				      ptep_level, GSTAGE_OP_CLEAR);
292
293next:
294		addr += page_size;
295
296		/*
297		 * If the range is too large, release the kvm->mmu_lock
298		 * to prevent starvation and lockup detector warnings.
299		 */
300		if (may_block && addr < end)
301			cond_resched_lock(&kvm->mmu_lock);
302	}
303}
304
305static void gstage_wp_range(struct kvm *kvm, gpa_t start, gpa_t end)
306{
307	int ret;
308	pte_t *ptep;
309	u32 ptep_level;
310	bool found_leaf;
311	gpa_t addr = start;
312	unsigned long page_size;
313
314	while (addr < end) {
315		found_leaf = gstage_get_leaf_entry(kvm, addr,
316						   &ptep, &ptep_level);
317		ret = gstage_level_to_page_size(ptep_level, &page_size);
318		if (ret)
319			break;
320
321		if (!found_leaf)
322			goto next;
323
324		if (!(addr & (page_size - 1)) && ((end - addr) >= page_size))
325			gstage_op_pte(kvm, addr, ptep,
326				      ptep_level, GSTAGE_OP_WP);
327
328next:
329		addr += page_size;
330	}
331}
332
333static void gstage_wp_memory_region(struct kvm *kvm, int slot)
334{
335	struct kvm_memslots *slots = kvm_memslots(kvm);
336	struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
337	phys_addr_t start = memslot->base_gfn << PAGE_SHIFT;
338	phys_addr_t end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
339
340	spin_lock(&kvm->mmu_lock);
341	gstage_wp_range(kvm, start, end);
342	spin_unlock(&kvm->mmu_lock);
343	kvm_flush_remote_tlbs(kvm);
344}
345
346int kvm_riscv_gstage_ioremap(struct kvm *kvm, gpa_t gpa,
347			     phys_addr_t hpa, unsigned long size,
348			     bool writable, bool in_atomic)
349{
350	pte_t pte;
351	int ret = 0;
352	unsigned long pfn;
353	phys_addr_t addr, end;
354	struct kvm_mmu_memory_cache pcache = {
355		.gfp_custom = (in_atomic) ? GFP_ATOMIC | __GFP_ACCOUNT : 0,
356		.gfp_zero = __GFP_ZERO,
357	};
358
359	end = (gpa + size + PAGE_SIZE - 1) & PAGE_MASK;
360	pfn = __phys_to_pfn(hpa);
361
362	for (addr = gpa; addr < end; addr += PAGE_SIZE) {
363		pte = pfn_pte(pfn, PAGE_KERNEL_IO);
364
365		if (!writable)
366			pte = pte_wrprotect(pte);
367
368		ret = kvm_mmu_topup_memory_cache(&pcache, gstage_pgd_levels);
369		if (ret)
370			goto out;
371
372		spin_lock(&kvm->mmu_lock);
373		ret = gstage_set_pte(kvm, 0, &pcache, addr, &pte);
374		spin_unlock(&kvm->mmu_lock);
375		if (ret)
376			goto out;
377
378		pfn++;
379	}
380
381out:
382	kvm_mmu_free_memory_cache(&pcache);
383	return ret;
384}
385
386void kvm_riscv_gstage_iounmap(struct kvm *kvm, gpa_t gpa, unsigned long size)
387{
388	spin_lock(&kvm->mmu_lock);
389	gstage_unmap_range(kvm, gpa, size, false);
390	spin_unlock(&kvm->mmu_lock);
391}
392
393void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
394					     struct kvm_memory_slot *slot,
395					     gfn_t gfn_offset,
396					     unsigned long mask)
397{
398	phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
399	phys_addr_t start = (base_gfn +  __ffs(mask)) << PAGE_SHIFT;
400	phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
401
402	gstage_wp_range(kvm, start, end);
403}
404
405void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
406{
407}
408
409void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free)
410{
411}
412
413void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen)
414{
415}
416
417void kvm_arch_flush_shadow_all(struct kvm *kvm)
418{
419	kvm_riscv_gstage_free_pgd(kvm);
420}
421
422void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
423				   struct kvm_memory_slot *slot)
424{
425	gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
426	phys_addr_t size = slot->npages << PAGE_SHIFT;
427
428	spin_lock(&kvm->mmu_lock);
429	gstage_unmap_range(kvm, gpa, size, false);
430	spin_unlock(&kvm->mmu_lock);
431}
432
433void kvm_arch_commit_memory_region(struct kvm *kvm,
434				struct kvm_memory_slot *old,
435				const struct kvm_memory_slot *new,
436				enum kvm_mr_change change)
437{
438	/*
439	 * At this point memslot has been committed and there is an
440	 * allocated dirty_bitmap[], dirty pages will be tracked while
441	 * the memory slot is write protected.
442	 */
443	if (change != KVM_MR_DELETE && new->flags & KVM_MEM_LOG_DIRTY_PAGES)
444		gstage_wp_memory_region(kvm, new->id);
445}
446
447int kvm_arch_prepare_memory_region(struct kvm *kvm,
448				const struct kvm_memory_slot *old,
449				struct kvm_memory_slot *new,
450				enum kvm_mr_change change)
451{
452	hva_t hva, reg_end, size;
453	gpa_t base_gpa;
454	bool writable;
455	int ret = 0;
456
457	if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
458			change != KVM_MR_FLAGS_ONLY)
459		return 0;
460
461	/*
462	 * Prevent userspace from creating a memory region outside of the GPA
463	 * space addressable by the KVM guest GPA space.
464	 */
465	if ((new->base_gfn + new->npages) >=
466	    (gstage_gpa_size >> PAGE_SHIFT))
467		return -EFAULT;
468
469	hva = new->userspace_addr;
470	size = new->npages << PAGE_SHIFT;
471	reg_end = hva + size;
472	base_gpa = new->base_gfn << PAGE_SHIFT;
473	writable = !(new->flags & KVM_MEM_READONLY);
474
475	mmap_read_lock(current->mm);
476
477	/*
478	 * A memory region could potentially cover multiple VMAs, and
479	 * any holes between them, so iterate over all of them to find
480	 * out if we can map any of them right now.
481	 *
482	 *     +--------------------------------------------+
483	 * +---------------+----------------+   +----------------+
484	 * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
485	 * +---------------+----------------+   +----------------+
486	 *     |               memory region                |
487	 *     +--------------------------------------------+
488	 */
489	do {
490		struct vm_area_struct *vma = find_vma(current->mm, hva);
491		hva_t vm_start, vm_end;
492
493		if (!vma || vma->vm_start >= reg_end)
494			break;
495
496		/*
497		 * Mapping a read-only VMA is only allowed if the
498		 * memory region is configured as read-only.
499		 */
500		if (writable && !(vma->vm_flags & VM_WRITE)) {
501			ret = -EPERM;
502			break;
503		}
504
505		/* Take the intersection of this VMA with the memory region */
506		vm_start = max(hva, vma->vm_start);
507		vm_end = min(reg_end, vma->vm_end);
508
509		if (vma->vm_flags & VM_PFNMAP) {
510			gpa_t gpa = base_gpa + (vm_start - hva);
511			phys_addr_t pa;
512
513			pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
514			pa += vm_start - vma->vm_start;
515
516			/* IO region dirty page logging not allowed */
517			if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
518				ret = -EINVAL;
519				goto out;
520			}
521
522			ret = kvm_riscv_gstage_ioremap(kvm, gpa, pa,
523						       vm_end - vm_start,
524						       writable, false);
525			if (ret)
526				break;
527		}
528		hva = vm_end;
529	} while (hva < reg_end);
530
531	if (change == KVM_MR_FLAGS_ONLY)
532		goto out;
533
534	if (ret)
535		kvm_riscv_gstage_iounmap(kvm, base_gpa, size);
536
537out:
538	mmap_read_unlock(current->mm);
539	return ret;
540}
541
542bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
543{
544	if (!kvm->arch.pgd)
545		return false;
546
547	gstage_unmap_range(kvm, range->start << PAGE_SHIFT,
548			   (range->end - range->start) << PAGE_SHIFT,
549			   range->may_block);
550	return false;
551}
552
553bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
554{
555	int ret;
556	kvm_pfn_t pfn = pte_pfn(range->arg.pte);
557
558	if (!kvm->arch.pgd)
559		return false;
560
561	WARN_ON(range->end - range->start != 1);
562
563	ret = gstage_map_page(kvm, NULL, range->start << PAGE_SHIFT,
564			      __pfn_to_phys(pfn), PAGE_SIZE, true, true);
565	if (ret) {
566		kvm_debug("Failed to map G-stage page (error %d)\n", ret);
567		return true;
568	}
569
570	return false;
571}
572
573bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
574{
575	pte_t *ptep;
576	u32 ptep_level = 0;
577	u64 size = (range->end - range->start) << PAGE_SHIFT;
578
579	if (!kvm->arch.pgd)
580		return false;
581
582	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
583
584	if (!gstage_get_leaf_entry(kvm, range->start << PAGE_SHIFT,
585				   &ptep, &ptep_level))
586		return false;
587
588	return ptep_test_and_clear_young(NULL, 0, ptep);
589}
590
591bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
592{
593	pte_t *ptep;
594	u32 ptep_level = 0;
595	u64 size = (range->end - range->start) << PAGE_SHIFT;
596
597	if (!kvm->arch.pgd)
598		return false;
599
600	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
601
602	if (!gstage_get_leaf_entry(kvm, range->start << PAGE_SHIFT,
603				   &ptep, &ptep_level))
604		return false;
605
606	return pte_young(ptep_get(ptep));
607}
608
609int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
610			 struct kvm_memory_slot *memslot,
611			 gpa_t gpa, unsigned long hva, bool is_write)
612{
613	int ret;
614	kvm_pfn_t hfn;
615	bool writable;
616	short vma_pageshift;
617	gfn_t gfn = gpa >> PAGE_SHIFT;
618	struct vm_area_struct *vma;
619	struct kvm *kvm = vcpu->kvm;
620	struct kvm_mmu_memory_cache *pcache = &vcpu->arch.mmu_page_cache;
621	bool logging = (memslot->dirty_bitmap &&
622			!(memslot->flags & KVM_MEM_READONLY)) ? true : false;
623	unsigned long vma_pagesize, mmu_seq;
624
625	/* We need minimum second+third level pages */
626	ret = kvm_mmu_topup_memory_cache(pcache, gstage_pgd_levels);
627	if (ret) {
628		kvm_err("Failed to topup G-stage cache\n");
629		return ret;
630	}
631
632	mmap_read_lock(current->mm);
633
634	vma = vma_lookup(current->mm, hva);
635	if (unlikely(!vma)) {
636		kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
637		mmap_read_unlock(current->mm);
638		return -EFAULT;
639	}
640
641	if (is_vm_hugetlb_page(vma))
642		vma_pageshift = huge_page_shift(hstate_vma(vma));
643	else
644		vma_pageshift = PAGE_SHIFT;
645	vma_pagesize = 1ULL << vma_pageshift;
646	if (logging || (vma->vm_flags & VM_PFNMAP))
647		vma_pagesize = PAGE_SIZE;
648
649	if (vma_pagesize == PMD_SIZE || vma_pagesize == PUD_SIZE)
650		gfn = (gpa & huge_page_mask(hstate_vma(vma))) >> PAGE_SHIFT;
651
652	/*
653	 * Read mmu_invalidate_seq so that KVM can detect if the results of
654	 * vma_lookup() or gfn_to_pfn_prot() become stale priort to acquiring
655	 * kvm->mmu_lock.
656	 *
657	 * Rely on mmap_read_unlock() for an implicit smp_rmb(), which pairs
658	 * with the smp_wmb() in kvm_mmu_invalidate_end().
659	 */
660	mmu_seq = kvm->mmu_invalidate_seq;
661	mmap_read_unlock(current->mm);
662
663	if (vma_pagesize != PUD_SIZE &&
664	    vma_pagesize != PMD_SIZE &&
665	    vma_pagesize != PAGE_SIZE) {
666		kvm_err("Invalid VMA page size 0x%lx\n", vma_pagesize);
667		return -EFAULT;
668	}
669
670	hfn = gfn_to_pfn_prot(kvm, gfn, is_write, &writable);
671	if (hfn == KVM_PFN_ERR_HWPOISON) {
672		send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva,
673				vma_pageshift, current);
674		return 0;
675	}
676	if (is_error_noslot_pfn(hfn))
677		return -EFAULT;
678
679	/*
680	 * If logging is active then we allow writable pages only
681	 * for write faults.
682	 */
683	if (logging && !is_write)
684		writable = false;
685
686	spin_lock(&kvm->mmu_lock);
687
688	if (mmu_invalidate_retry(kvm, mmu_seq))
689		goto out_unlock;
690
691	if (writable) {
692		kvm_set_pfn_dirty(hfn);
693		mark_page_dirty(kvm, gfn);
694		ret = gstage_map_page(kvm, pcache, gpa, hfn << PAGE_SHIFT,
695				      vma_pagesize, false, true);
696	} else {
697		ret = gstage_map_page(kvm, pcache, gpa, hfn << PAGE_SHIFT,
698				      vma_pagesize, true, true);
699	}
700
701	if (ret)
702		kvm_err("Failed to map in G-stage\n");
703
704out_unlock:
705	spin_unlock(&kvm->mmu_lock);
706	kvm_set_pfn_accessed(hfn);
707	kvm_release_pfn_clean(hfn);
708	return ret;
709}
710
711int kvm_riscv_gstage_alloc_pgd(struct kvm *kvm)
712{
713	struct page *pgd_page;
714
715	if (kvm->arch.pgd != NULL) {
716		kvm_err("kvm_arch already initialized?\n");
717		return -EINVAL;
718	}
719
720	pgd_page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
721				get_order(gstage_pgd_size));
722	if (!pgd_page)
723		return -ENOMEM;
724	kvm->arch.pgd = page_to_virt(pgd_page);
725	kvm->arch.pgd_phys = page_to_phys(pgd_page);
726
727	return 0;
728}
729
730void kvm_riscv_gstage_free_pgd(struct kvm *kvm)
731{
732	void *pgd = NULL;
733
734	spin_lock(&kvm->mmu_lock);
735	if (kvm->arch.pgd) {
736		gstage_unmap_range(kvm, 0UL, gstage_gpa_size, false);
737		pgd = READ_ONCE(kvm->arch.pgd);
738		kvm->arch.pgd = NULL;
739		kvm->arch.pgd_phys = 0;
740	}
741	spin_unlock(&kvm->mmu_lock);
742
743	if (pgd)
744		free_pages((unsigned long)pgd, get_order(gstage_pgd_size));
745}
746
747void kvm_riscv_gstage_update_hgatp(struct kvm_vcpu *vcpu)
748{
749	unsigned long hgatp = gstage_mode;
750	struct kvm_arch *k = &vcpu->kvm->arch;
751
752	hgatp |= (READ_ONCE(k->vmid.vmid) << HGATP_VMID_SHIFT) & HGATP_VMID;
753	hgatp |= (k->pgd_phys >> PAGE_SHIFT) & HGATP_PPN;
754
755	csr_write(CSR_HGATP, hgatp);
756
757	if (!kvm_riscv_gstage_vmid_bits())
758		kvm_riscv_local_hfence_gvma_all();
759}
760
761void __init kvm_riscv_gstage_mode_detect(void)
762{
763#ifdef CONFIG_64BIT
764	/* Try Sv57x4 G-stage mode */
765	csr_write(CSR_HGATP, HGATP_MODE_SV57X4 << HGATP_MODE_SHIFT);
766	if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV57X4) {
767		gstage_mode = (HGATP_MODE_SV57X4 << HGATP_MODE_SHIFT);
768		gstage_pgd_levels = 5;
769		goto skip_sv48x4_test;
770	}
771
772	/* Try Sv48x4 G-stage mode */
773	csr_write(CSR_HGATP, HGATP_MODE_SV48X4 << HGATP_MODE_SHIFT);
774	if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV48X4) {
775		gstage_mode = (HGATP_MODE_SV48X4 << HGATP_MODE_SHIFT);
776		gstage_pgd_levels = 4;
777	}
778skip_sv48x4_test:
779
780	csr_write(CSR_HGATP, 0);
781	kvm_riscv_local_hfence_gvma_all();
782#endif
783}
784
785unsigned long __init kvm_riscv_gstage_mode(void)
786{
787	return gstage_mode >> HGATP_MODE_SHIFT;
788}
789
790int kvm_riscv_gstage_gpa_bits(void)
791{
792	return gstage_gpa_bits;
793}
794