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
23 static unsigned long gstage_mode __ro_after_init = (HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT);
24 static unsigned long gstage_pgd_levels __ro_after_init = 3;
25 #define gstage_index_bits 9
26 #else
27 static unsigned long gstage_mode __ro_after_init = (HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT);
28 static 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
gstage_pte_index(gpa_t addr,u32 level)42 static 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
gstage_pte_page_vaddr(pte_t pte)55 static 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
gstage_page_size_to_level(unsigned long page_size,u32 * out_level)60 static 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
gstage_level_to_page_order(u32 level,unsigned long * out_pgorder)75 static 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
gstage_level_to_page_size(u32 level,unsigned long * out_pgsize)84 static 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
gstage_get_leaf_entry(struct kvm * kvm,gpa_t addr,pte_t ** ptepp,u32 * ptep_level)97 static 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)) {
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);
117 ptep = &ptep[gstage_pte_index(addr, current_level)];
118 } else {
119 ptep = NULL;
120 }
121 }
122
123 return false;
124 }
125
gstage_remote_tlb_flush(struct kvm * kvm,u32 level,gpa_t addr)126 static 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
gstage_set_pte(struct kvm * kvm,u32 level,struct kvm_mmu_memory_cache * pcache,gpa_t addr,const pte_t * new_pte)137 static 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)) {
153 if (!pcache)
154 return -ENOMEM;
155 next_ptep = kvm_mmu_memory_cache_alloc(pcache);
156 if (!next_ptep)
157 return -ENOMEM;
158 *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);
164 }
165
166 current_level--;
167 ptep = &next_ptep[gstage_pte_index(addr, current_level)];
168 }
169
170 *ptep = *new_pte;
171 if (gstage_pte_leaf(ptep))
172 gstage_remote_tlb_flush(kvm, current_level, addr);
173
174 return 0;
175 }
176
gstage_map_page(struct kvm * kvm,struct kvm_mmu_memory_cache * pcache,gpa_t gpa,phys_addr_t hpa,unsigned long page_size,bool page_rdonly,bool page_exec)177 static 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
222 enum gstage_op {
223 GSTAGE_OP_NOP = 0, /* Nothing */
224 GSTAGE_OP_CLEAR, /* Clear/Unmap */
225 GSTAGE_OP_WP, /* Write-protect */
226 };
227
gstage_op_pte(struct kvm * kvm,gpa_t addr,pte_t * ptep,u32 ptep_level,enum gstage_op op)228 static 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))
243 return;
244
245 if (ptep_level && !gstage_pte_leaf(ptep)) {
246 next_ptep = (pte_t *)gstage_pte_page_vaddr(*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) & ~_PAGE_WRITE));
265 gstage_remote_tlb_flush(kvm, ptep_level, addr);
266 }
267 }
268
gstage_unmap_range(struct kvm * kvm,gpa_t start,gpa_t size,bool may_block)269 static 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
293 next:
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
gstage_wp_range(struct kvm * kvm,gpa_t start,gpa_t end)305 static 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
328 next:
329 addr += page_size;
330 }
331 }
332
gstage_wp_memory_region(struct kvm * kvm,int slot)333 static 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
kvm_riscv_gstage_ioremap(struct kvm * kvm,gpa_t gpa,phys_addr_t hpa,unsigned long size,bool writable,bool in_atomic)346 int 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
381 out:
382 kvm_mmu_free_memory_cache(&pcache);
383 return ret;
384 }
385
kvm_riscv_gstage_iounmap(struct kvm * kvm,gpa_t gpa,unsigned long size)386 void 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
kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm * kvm,struct kvm_memory_slot * slot,gfn_t gfn_offset,unsigned long mask)393 void 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
kvm_arch_sync_dirty_log(struct kvm * kvm,struct kvm_memory_slot * memslot)405 void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
406 {
407 }
408
kvm_arch_flush_remote_tlbs_memslot(struct kvm * kvm,const struct kvm_memory_slot * memslot)409 void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
410 const struct kvm_memory_slot *memslot)
411 {
412 kvm_flush_remote_tlbs(kvm);
413 }
414
kvm_arch_free_memslot(struct kvm * kvm,struct kvm_memory_slot * free)415 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free)
416 {
417 }
418
kvm_arch_memslots_updated(struct kvm * kvm,u64 gen)419 void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen)
420 {
421 }
422
kvm_arch_flush_shadow_all(struct kvm * kvm)423 void kvm_arch_flush_shadow_all(struct kvm *kvm)
424 {
425 kvm_riscv_gstage_free_pgd(kvm);
426 }
427
kvm_arch_flush_shadow_memslot(struct kvm * kvm,struct kvm_memory_slot * slot)428 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
429 struct kvm_memory_slot *slot)
430 {
431 gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
432 phys_addr_t size = slot->npages << PAGE_SHIFT;
433
434 spin_lock(&kvm->mmu_lock);
435 gstage_unmap_range(kvm, gpa, size, false);
436 spin_unlock(&kvm->mmu_lock);
437 }
438
kvm_arch_commit_memory_region(struct kvm * kvm,struct kvm_memory_slot * old,const struct kvm_memory_slot * new,enum kvm_mr_change change)439 void kvm_arch_commit_memory_region(struct kvm *kvm,
440 struct kvm_memory_slot *old,
441 const struct kvm_memory_slot *new,
442 enum kvm_mr_change change)
443 {
444 /*
445 * At this point memslot has been committed and there is an
446 * allocated dirty_bitmap[], dirty pages will be tracked while
447 * the memory slot is write protected.
448 */
449 if (change != KVM_MR_DELETE && new->flags & KVM_MEM_LOG_DIRTY_PAGES)
450 gstage_wp_memory_region(kvm, new->id);
451 }
452
kvm_arch_prepare_memory_region(struct kvm * kvm,const struct kvm_memory_slot * old,struct kvm_memory_slot * new,enum kvm_mr_change change)453 int kvm_arch_prepare_memory_region(struct kvm *kvm,
454 const struct kvm_memory_slot *old,
455 struct kvm_memory_slot *new,
456 enum kvm_mr_change change)
457 {
458 hva_t hva, reg_end, size;
459 gpa_t base_gpa;
460 bool writable;
461 int ret = 0;
462
463 if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
464 change != KVM_MR_FLAGS_ONLY)
465 return 0;
466
467 /*
468 * Prevent userspace from creating a memory region outside of the GPA
469 * space addressable by the KVM guest GPA space.
470 */
471 if ((new->base_gfn + new->npages) >=
472 (gstage_gpa_size >> PAGE_SHIFT))
473 return -EFAULT;
474
475 hva = new->userspace_addr;
476 size = new->npages << PAGE_SHIFT;
477 reg_end = hva + size;
478 base_gpa = new->base_gfn << PAGE_SHIFT;
479 writable = !(new->flags & KVM_MEM_READONLY);
480
481 mmap_read_lock(current->mm);
482
483 /*
484 * A memory region could potentially cover multiple VMAs, and
485 * any holes between them, so iterate over all of them to find
486 * out if we can map any of them right now.
487 *
488 * +--------------------------------------------+
489 * +---------------+----------------+ +----------------+
490 * | : VMA 1 | VMA 2 | | VMA 3 : |
491 * +---------------+----------------+ +----------------+
492 * | memory region |
493 * +--------------------------------------------+
494 */
495 do {
496 struct vm_area_struct *vma = find_vma(current->mm, hva);
497 hva_t vm_start, vm_end;
498
499 if (!vma || vma->vm_start >= reg_end)
500 break;
501
502 /*
503 * Mapping a read-only VMA is only allowed if the
504 * memory region is configured as read-only.
505 */
506 if (writable && !(vma->vm_flags & VM_WRITE)) {
507 ret = -EPERM;
508 break;
509 }
510
511 /* Take the intersection of this VMA with the memory region */
512 vm_start = max(hva, vma->vm_start);
513 vm_end = min(reg_end, vma->vm_end);
514
515 if (vma->vm_flags & VM_PFNMAP) {
516 gpa_t gpa = base_gpa + (vm_start - hva);
517 phys_addr_t pa;
518
519 pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
520 pa += vm_start - vma->vm_start;
521
522 /* IO region dirty page logging not allowed */
523 if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
524 ret = -EINVAL;
525 goto out;
526 }
527
528 ret = kvm_riscv_gstage_ioremap(kvm, gpa, pa,
529 vm_end - vm_start,
530 writable, false);
531 if (ret)
532 break;
533 }
534 hva = vm_end;
535 } while (hva < reg_end);
536
537 if (change == KVM_MR_FLAGS_ONLY)
538 goto out;
539
540 if (ret)
541 kvm_riscv_gstage_iounmap(kvm, base_gpa, size);
542
543 out:
544 mmap_read_unlock(current->mm);
545 return ret;
546 }
547
kvm_unmap_gfn_range(struct kvm * kvm,struct kvm_gfn_range * range)548 bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
549 {
550 if (!kvm->arch.pgd)
551 return false;
552
553 gstage_unmap_range(kvm, range->start << PAGE_SHIFT,
554 (range->end - range->start) << PAGE_SHIFT,
555 range->may_block);
556 return false;
557 }
558
kvm_set_spte_gfn(struct kvm * kvm,struct kvm_gfn_range * range)559 bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
560 {
561 int ret;
562 kvm_pfn_t pfn = pte_pfn(range->pte);
563
564 if (!kvm->arch.pgd)
565 return false;
566
567 WARN_ON(range->end - range->start != 1);
568
569 ret = gstage_map_page(kvm, NULL, range->start << PAGE_SHIFT,
570 __pfn_to_phys(pfn), PAGE_SIZE, true, true);
571 if (ret) {
572 kvm_debug("Failed to map G-stage page (error %d)\n", ret);
573 return true;
574 }
575
576 return false;
577 }
578
kvm_age_gfn(struct kvm * kvm,struct kvm_gfn_range * range)579 bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
580 {
581 pte_t *ptep;
582 u32 ptep_level = 0;
583 u64 size = (range->end - range->start) << PAGE_SHIFT;
584
585 if (!kvm->arch.pgd)
586 return false;
587
588 WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
589
590 if (!gstage_get_leaf_entry(kvm, range->start << PAGE_SHIFT,
591 &ptep, &ptep_level))
592 return false;
593
594 return ptep_test_and_clear_young(NULL, 0, ptep);
595 }
596
kvm_test_age_gfn(struct kvm * kvm,struct kvm_gfn_range * range)597 bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
598 {
599 pte_t *ptep;
600 u32 ptep_level = 0;
601 u64 size = (range->end - range->start) << PAGE_SHIFT;
602
603 if (!kvm->arch.pgd)
604 return false;
605
606 WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
607
608 if (!gstage_get_leaf_entry(kvm, range->start << PAGE_SHIFT,
609 &ptep, &ptep_level))
610 return false;
611
612 return pte_young(*ptep);
613 }
614
kvm_riscv_gstage_map(struct kvm_vcpu * vcpu,struct kvm_memory_slot * memslot,gpa_t gpa,unsigned long hva,bool is_write)615 int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
616 struct kvm_memory_slot *memslot,
617 gpa_t gpa, unsigned long hva, bool is_write)
618 {
619 int ret;
620 kvm_pfn_t hfn;
621 bool writable;
622 short vma_pageshift;
623 gfn_t gfn = gpa >> PAGE_SHIFT;
624 struct vm_area_struct *vma;
625 struct kvm *kvm = vcpu->kvm;
626 struct kvm_mmu_memory_cache *pcache = &vcpu->arch.mmu_page_cache;
627 bool logging = (memslot->dirty_bitmap &&
628 !(memslot->flags & KVM_MEM_READONLY)) ? true : false;
629 unsigned long vma_pagesize, mmu_seq;
630
631 mmap_read_lock(current->mm);
632
633 vma = vma_lookup(current->mm, hva);
634 if (unlikely(!vma)) {
635 kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
636 mmap_read_unlock(current->mm);
637 return -EFAULT;
638 }
639
640 if (is_vm_hugetlb_page(vma))
641 vma_pageshift = huge_page_shift(hstate_vma(vma));
642 else
643 vma_pageshift = PAGE_SHIFT;
644 vma_pagesize = 1ULL << vma_pageshift;
645 if (logging || (vma->vm_flags & VM_PFNMAP))
646 vma_pagesize = PAGE_SIZE;
647
648 if (vma_pagesize == PMD_SIZE || vma_pagesize == PUD_SIZE)
649 gfn = (gpa & huge_page_mask(hstate_vma(vma))) >> PAGE_SHIFT;
650
651 mmap_read_unlock(current->mm);
652
653 if (vma_pagesize != PUD_SIZE &&
654 vma_pagesize != PMD_SIZE &&
655 vma_pagesize != PAGE_SIZE) {
656 kvm_err("Invalid VMA page size 0x%lx\n", vma_pagesize);
657 return -EFAULT;
658 }
659
660 /* We need minimum second+third level pages */
661 ret = kvm_mmu_topup_memory_cache(pcache, gstage_pgd_levels);
662 if (ret) {
663 kvm_err("Failed to topup G-stage cache\n");
664 return ret;
665 }
666
667 mmu_seq = kvm->mmu_invalidate_seq;
668
669 hfn = gfn_to_pfn_prot(kvm, gfn, is_write, &writable);
670 if (hfn == KVM_PFN_ERR_HWPOISON) {
671 send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva,
672 vma_pageshift, current);
673 return 0;
674 }
675 if (is_error_noslot_pfn(hfn))
676 return -EFAULT;
677
678 /*
679 * If logging is active then we allow writable pages only
680 * for write faults.
681 */
682 if (logging && !is_write)
683 writable = false;
684
685 spin_lock(&kvm->mmu_lock);
686
687 if (mmu_invalidate_retry(kvm, mmu_seq))
688 goto out_unlock;
689
690 if (writable) {
691 kvm_set_pfn_dirty(hfn);
692 mark_page_dirty(kvm, gfn);
693 ret = gstage_map_page(kvm, pcache, gpa, hfn << PAGE_SHIFT,
694 vma_pagesize, false, true);
695 } else {
696 ret = gstage_map_page(kvm, pcache, gpa, hfn << PAGE_SHIFT,
697 vma_pagesize, true, true);
698 }
699
700 if (ret)
701 kvm_err("Failed to map in G-stage\n");
702
703 out_unlock:
704 spin_unlock(&kvm->mmu_lock);
705 kvm_set_pfn_accessed(hfn);
706 kvm_release_pfn_clean(hfn);
707 return ret;
708 }
709
kvm_riscv_gstage_alloc_pgd(struct kvm * kvm)710 int kvm_riscv_gstage_alloc_pgd(struct kvm *kvm)
711 {
712 struct page *pgd_page;
713
714 if (kvm->arch.pgd != NULL) {
715 kvm_err("kvm_arch already initialized?\n");
716 return -EINVAL;
717 }
718
719 pgd_page = alloc_pages(GFP_KERNEL | __GFP_ZERO,
720 get_order(gstage_pgd_size));
721 if (!pgd_page)
722 return -ENOMEM;
723 kvm->arch.pgd = page_to_virt(pgd_page);
724 kvm->arch.pgd_phys = page_to_phys(pgd_page);
725
726 return 0;
727 }
728
kvm_riscv_gstage_free_pgd(struct kvm * kvm)729 void kvm_riscv_gstage_free_pgd(struct kvm *kvm)
730 {
731 void *pgd = NULL;
732
733 spin_lock(&kvm->mmu_lock);
734 if (kvm->arch.pgd) {
735 gstage_unmap_range(kvm, 0UL, gstage_gpa_size, false);
736 pgd = READ_ONCE(kvm->arch.pgd);
737 kvm->arch.pgd = NULL;
738 kvm->arch.pgd_phys = 0;
739 }
740 spin_unlock(&kvm->mmu_lock);
741
742 if (pgd)
743 free_pages((unsigned long)pgd, get_order(gstage_pgd_size));
744 }
745
kvm_riscv_gstage_update_hgatp(struct kvm_vcpu * vcpu)746 void kvm_riscv_gstage_update_hgatp(struct kvm_vcpu *vcpu)
747 {
748 unsigned long hgatp = gstage_mode;
749 struct kvm_arch *k = &vcpu->kvm->arch;
750
751 hgatp |= (READ_ONCE(k->vmid.vmid) << HGATP_VMID_SHIFT) &
752 HGATP_VMID_MASK;
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
kvm_riscv_gstage_mode_detect(void)761 void __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 }
778 skip_sv48x4_test:
779
780 csr_write(CSR_HGATP, 0);
781 kvm_riscv_local_hfence_gvma_all();
782 #endif
783 }
784
kvm_riscv_gstage_mode(void)785 unsigned long __init kvm_riscv_gstage_mode(void)
786 {
787 return gstage_mode >> HGATP_MODE_SHIFT;
788 }
789
kvm_riscv_gstage_gpa_bits(void)790 int kvm_riscv_gstage_gpa_bits(void)
791 {
792 return gstage_gpa_bits;
793 }
794