1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Copyright 2016 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
5 */
6
7 #include <linux/types.h>
8 #include <linux/string.h>
9 #include <linux/kvm.h>
10 #include <linux/kvm_host.h>
11 #include <linux/anon_inodes.h>
12 #include <linux/file.h>
13 #include <linux/debugfs.h>
14 #include <linux/pgtable.h>
15
16 #include <asm/kvm_ppc.h>
17 #include <asm/kvm_book3s.h>
18 #include <asm/page.h>
19 #include <asm/mmu.h>
20 #include <asm/pgalloc.h>
21 #include <asm/pte-walk.h>
22 #include <asm/ultravisor.h>
23 #include <asm/kvm_book3s_uvmem.h>
24 #include <asm/plpar_wrappers.h>
25 #include <asm/firmware.h>
26
27 /*
28 * Supported radix tree geometry.
29 * Like p9, we support either 5 or 9 bits at the first (lowest) level,
30 * for a page size of 64k or 4k.
31 */
32 static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
33
__kvmhv_copy_tofrom_guest_radix(int lpid,int pid,gva_t eaddr,void * to,void * from,unsigned long n)34 unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
35 gva_t eaddr, void *to, void *from,
36 unsigned long n)
37 {
38 int old_pid, old_lpid;
39 unsigned long quadrant, ret = n;
40 bool is_load = !!to;
41
42 /* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */
43 if (kvmhv_on_pseries())
44 return plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr,
45 (to != NULL) ? __pa(to): 0,
46 (from != NULL) ? __pa(from): 0, n);
47
48 if (eaddr & (0xFFFUL << 52))
49 return ret;
50
51 quadrant = 1;
52 if (!pid)
53 quadrant = 2;
54 if (is_load)
55 from = (void *) (eaddr | (quadrant << 62));
56 else
57 to = (void *) (eaddr | (quadrant << 62));
58
59 preempt_disable();
60
61 asm volatile("hwsync" ::: "memory");
62 isync();
63 /* switch the lpid first to avoid running host with unallocated pid */
64 old_lpid = mfspr(SPRN_LPID);
65 if (old_lpid != lpid)
66 mtspr(SPRN_LPID, lpid);
67 if (quadrant == 1) {
68 old_pid = mfspr(SPRN_PID);
69 if (old_pid != pid)
70 mtspr(SPRN_PID, pid);
71 }
72 isync();
73
74 pagefault_disable();
75 if (is_load)
76 ret = __copy_from_user_inatomic(to, (const void __user *)from, n);
77 else
78 ret = __copy_to_user_inatomic((void __user *)to, from, n);
79 pagefault_enable();
80
81 asm volatile("hwsync" ::: "memory");
82 isync();
83 /* switch the pid first to avoid running host with unallocated pid */
84 if (quadrant == 1 && pid != old_pid)
85 mtspr(SPRN_PID, old_pid);
86 if (lpid != old_lpid)
87 mtspr(SPRN_LPID, old_lpid);
88 isync();
89
90 preempt_enable();
91
92 return ret;
93 }
94
kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu * vcpu,gva_t eaddr,void * to,void * from,unsigned long n)95 static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
96 void *to, void *from, unsigned long n)
97 {
98 int lpid = vcpu->kvm->arch.lpid;
99 int pid = vcpu->arch.pid;
100
101 /* This would cause a data segment intr so don't allow the access */
102 if (eaddr & (0x3FFUL << 52))
103 return -EINVAL;
104
105 /* Should we be using the nested lpid */
106 if (vcpu->arch.nested)
107 lpid = vcpu->arch.nested->shadow_lpid;
108
109 /* If accessing quadrant 3 then pid is expected to be 0 */
110 if (((eaddr >> 62) & 0x3) == 0x3)
111 pid = 0;
112
113 eaddr &= ~(0xFFFUL << 52);
114
115 return __kvmhv_copy_tofrom_guest_radix(lpid, pid, eaddr, to, from, n);
116 }
117
kvmhv_copy_from_guest_radix(struct kvm_vcpu * vcpu,gva_t eaddr,void * to,unsigned long n)118 long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to,
119 unsigned long n)
120 {
121 long ret;
122
123 ret = kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, to, NULL, n);
124 if (ret > 0)
125 memset(to + (n - ret), 0, ret);
126
127 return ret;
128 }
129
kvmhv_copy_to_guest_radix(struct kvm_vcpu * vcpu,gva_t eaddr,void * from,unsigned long n)130 long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *from,
131 unsigned long n)
132 {
133 return kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, NULL, from, n);
134 }
135
kvmppc_mmu_walk_radix_tree(struct kvm_vcpu * vcpu,gva_t eaddr,struct kvmppc_pte * gpte,u64 root,u64 * pte_ret_p)136 int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr,
137 struct kvmppc_pte *gpte, u64 root,
138 u64 *pte_ret_p)
139 {
140 struct kvm *kvm = vcpu->kvm;
141 int ret, level, ps;
142 unsigned long rts, bits, offset, index;
143 u64 pte, base, gpa;
144 __be64 rpte;
145
146 rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
147 ((root & RTS2_MASK) >> RTS2_SHIFT);
148 bits = root & RPDS_MASK;
149 base = root & RPDB_MASK;
150
151 offset = rts + 31;
152
153 /* Current implementations only support 52-bit space */
154 if (offset != 52)
155 return -EINVAL;
156
157 /* Walk each level of the radix tree */
158 for (level = 3; level >= 0; --level) {
159 u64 addr;
160 /* Check a valid size */
161 if (level && bits != p9_supported_radix_bits[level])
162 return -EINVAL;
163 if (level == 0 && !(bits == 5 || bits == 9))
164 return -EINVAL;
165 offset -= bits;
166 index = (eaddr >> offset) & ((1UL << bits) - 1);
167 /* Check that low bits of page table base are zero */
168 if (base & ((1UL << (bits + 3)) - 1))
169 return -EINVAL;
170 /* Read the entry from guest memory */
171 addr = base + (index * sizeof(rpte));
172
173 kvm_vcpu_srcu_read_lock(vcpu);
174 ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte));
175 kvm_vcpu_srcu_read_unlock(vcpu);
176 if (ret) {
177 if (pte_ret_p)
178 *pte_ret_p = addr;
179 return ret;
180 }
181 pte = __be64_to_cpu(rpte);
182 if (!(pte & _PAGE_PRESENT))
183 return -ENOENT;
184 /* Check if a leaf entry */
185 if (pte & _PAGE_PTE)
186 break;
187 /* Get ready to walk the next level */
188 base = pte & RPDB_MASK;
189 bits = pte & RPDS_MASK;
190 }
191
192 /* Need a leaf at lowest level; 512GB pages not supported */
193 if (level < 0 || level == 3)
194 return -EINVAL;
195
196 /* We found a valid leaf PTE */
197 /* Offset is now log base 2 of the page size */
198 gpa = pte & 0x01fffffffffff000ul;
199 if (gpa & ((1ul << offset) - 1))
200 return -EINVAL;
201 gpa |= eaddr & ((1ul << offset) - 1);
202 for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps)
203 if (offset == mmu_psize_defs[ps].shift)
204 break;
205 gpte->page_size = ps;
206 gpte->page_shift = offset;
207
208 gpte->eaddr = eaddr;
209 gpte->raddr = gpa;
210
211 /* Work out permissions */
212 gpte->may_read = !!(pte & _PAGE_READ);
213 gpte->may_write = !!(pte & _PAGE_WRITE);
214 gpte->may_execute = !!(pte & _PAGE_EXEC);
215
216 gpte->rc = pte & (_PAGE_ACCESSED | _PAGE_DIRTY);
217
218 if (pte_ret_p)
219 *pte_ret_p = pte;
220
221 return 0;
222 }
223
224 /*
225 * Used to walk a partition or process table radix tree in guest memory
226 * Note: We exploit the fact that a partition table and a process
227 * table have the same layout, a partition-scoped page table and a
228 * process-scoped page table have the same layout, and the 2nd
229 * doubleword of a partition table entry has the same layout as
230 * the PTCR register.
231 */
kvmppc_mmu_radix_translate_table(struct kvm_vcpu * vcpu,gva_t eaddr,struct kvmppc_pte * gpte,u64 table,int table_index,u64 * pte_ret_p)232 int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
233 struct kvmppc_pte *gpte, u64 table,
234 int table_index, u64 *pte_ret_p)
235 {
236 struct kvm *kvm = vcpu->kvm;
237 int ret;
238 unsigned long size, ptbl, root;
239 struct prtb_entry entry;
240
241 if ((table & PRTS_MASK) > 24)
242 return -EINVAL;
243 size = 1ul << ((table & PRTS_MASK) + 12);
244
245 /* Is the table big enough to contain this entry? */
246 if ((table_index * sizeof(entry)) >= size)
247 return -EINVAL;
248
249 /* Read the table to find the root of the radix tree */
250 ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry));
251 kvm_vcpu_srcu_read_lock(vcpu);
252 ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry));
253 kvm_vcpu_srcu_read_unlock(vcpu);
254 if (ret)
255 return ret;
256
257 /* Root is stored in the first double word */
258 root = be64_to_cpu(entry.prtb0);
259
260 return kvmppc_mmu_walk_radix_tree(vcpu, eaddr, gpte, root, pte_ret_p);
261 }
262
kvmppc_mmu_radix_xlate(struct kvm_vcpu * vcpu,gva_t eaddr,struct kvmppc_pte * gpte,bool data,bool iswrite)263 int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
264 struct kvmppc_pte *gpte, bool data, bool iswrite)
265 {
266 u32 pid;
267 u64 pte;
268 int ret;
269
270 /* Work out effective PID */
271 switch (eaddr >> 62) {
272 case 0:
273 pid = vcpu->arch.pid;
274 break;
275 case 3:
276 pid = 0;
277 break;
278 default:
279 return -EINVAL;
280 }
281
282 ret = kvmppc_mmu_radix_translate_table(vcpu, eaddr, gpte,
283 vcpu->kvm->arch.process_table, pid, &pte);
284 if (ret)
285 return ret;
286
287 /* Check privilege (applies only to process scoped translations) */
288 if (kvmppc_get_msr(vcpu) & MSR_PR) {
289 if (pte & _PAGE_PRIVILEGED) {
290 gpte->may_read = 0;
291 gpte->may_write = 0;
292 gpte->may_execute = 0;
293 }
294 } else {
295 if (!(pte & _PAGE_PRIVILEGED)) {
296 /* Check AMR/IAMR to see if strict mode is in force */
297 if (vcpu->arch.amr & (1ul << 62))
298 gpte->may_read = 0;
299 if (vcpu->arch.amr & (1ul << 63))
300 gpte->may_write = 0;
301 if (vcpu->arch.iamr & (1ul << 62))
302 gpte->may_execute = 0;
303 }
304 }
305
306 return 0;
307 }
308
kvmppc_radix_tlbie_page(struct kvm * kvm,unsigned long addr,unsigned int pshift,unsigned int lpid)309 void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
310 unsigned int pshift, unsigned int lpid)
311 {
312 unsigned long psize = PAGE_SIZE;
313 int psi;
314 long rc;
315 unsigned long rb;
316
317 if (pshift)
318 psize = 1UL << pshift;
319 else
320 pshift = PAGE_SHIFT;
321
322 addr &= ~(psize - 1);
323
324 if (!kvmhv_on_pseries()) {
325 radix__flush_tlb_lpid_page(lpid, addr, psize);
326 return;
327 }
328
329 psi = shift_to_mmu_psize(pshift);
330
331 if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE)) {
332 rb = addr | (mmu_get_ap(psi) << PPC_BITLSHIFT(58));
333 rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(0, 0, 1),
334 lpid, rb);
335 } else {
336 rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
337 H_RPTI_TYPE_NESTED |
338 H_RPTI_TYPE_TLB,
339 psize_to_rpti_pgsize(psi),
340 addr, addr + psize);
341 }
342
343 if (rc)
344 pr_err("KVM: TLB page invalidation hcall failed, rc=%ld\n", rc);
345 }
346
kvmppc_radix_flush_pwc(struct kvm * kvm,unsigned int lpid)347 static void kvmppc_radix_flush_pwc(struct kvm *kvm, unsigned int lpid)
348 {
349 long rc;
350
351 if (!kvmhv_on_pseries()) {
352 radix__flush_pwc_lpid(lpid);
353 return;
354 }
355
356 if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE))
357 rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(1, 0, 1),
358 lpid, TLBIEL_INVAL_SET_LPID);
359 else
360 rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
361 H_RPTI_TYPE_NESTED |
362 H_RPTI_TYPE_PWC, H_RPTI_PAGE_ALL,
363 0, -1UL);
364 if (rc)
365 pr_err("KVM: TLB PWC invalidation hcall failed, rc=%ld\n", rc);
366 }
367
kvmppc_radix_update_pte(struct kvm * kvm,pte_t * ptep,unsigned long clr,unsigned long set,unsigned long addr,unsigned int shift)368 static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep,
369 unsigned long clr, unsigned long set,
370 unsigned long addr, unsigned int shift)
371 {
372 return __radix_pte_update(ptep, clr, set);
373 }
374
kvmppc_radix_set_pte_at(struct kvm * kvm,unsigned long addr,pte_t * ptep,pte_t pte)375 static void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr,
376 pte_t *ptep, pte_t pte)
377 {
378 radix__set_pte_at(kvm->mm, addr, ptep, pte, 0);
379 }
380
381 static struct kmem_cache *kvm_pte_cache;
382 static struct kmem_cache *kvm_pmd_cache;
383
kvmppc_pte_alloc(void)384 static pte_t *kvmppc_pte_alloc(void)
385 {
386 pte_t *pte;
387
388 pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL);
389 /* pmd_populate() will only reference _pa(pte). */
390 kmemleak_ignore(pte);
391
392 return pte;
393 }
394
kvmppc_pte_free(pte_t * ptep)395 static void kvmppc_pte_free(pte_t *ptep)
396 {
397 kmem_cache_free(kvm_pte_cache, ptep);
398 }
399
kvmppc_pmd_alloc(void)400 static pmd_t *kvmppc_pmd_alloc(void)
401 {
402 pmd_t *pmd;
403
404 pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL);
405 /* pud_populate() will only reference _pa(pmd). */
406 kmemleak_ignore(pmd);
407
408 return pmd;
409 }
410
kvmppc_pmd_free(pmd_t * pmdp)411 static void kvmppc_pmd_free(pmd_t *pmdp)
412 {
413 kmem_cache_free(kvm_pmd_cache, pmdp);
414 }
415
416 /* Called with kvm->mmu_lock held */
kvmppc_unmap_pte(struct kvm * kvm,pte_t * pte,unsigned long gpa,unsigned int shift,const struct kvm_memory_slot * memslot,unsigned int lpid)417 void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, unsigned long gpa,
418 unsigned int shift,
419 const struct kvm_memory_slot *memslot,
420 unsigned int lpid)
421
422 {
423 unsigned long old;
424 unsigned long gfn = gpa >> PAGE_SHIFT;
425 unsigned long page_size = PAGE_SIZE;
426 unsigned long hpa;
427
428 old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift);
429 kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
430
431 /* The following only applies to L1 entries */
432 if (lpid != kvm->arch.lpid)
433 return;
434
435 if (!memslot) {
436 memslot = gfn_to_memslot(kvm, gfn);
437 if (!memslot)
438 return;
439 }
440 if (shift) { /* 1GB or 2MB page */
441 page_size = 1ul << shift;
442 if (shift == PMD_SHIFT)
443 kvm->stat.num_2M_pages--;
444 else if (shift == PUD_SHIFT)
445 kvm->stat.num_1G_pages--;
446 }
447
448 gpa &= ~(page_size - 1);
449 hpa = old & PTE_RPN_MASK;
450 kvmhv_remove_nest_rmap_range(kvm, memslot, gpa, hpa, page_size);
451
452 if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap)
453 kvmppc_update_dirty_map(memslot, gfn, page_size);
454 }
455
456 /*
457 * kvmppc_free_p?d are used to free existing page tables, and recursively
458 * descend and clear and free children.
459 * Callers are responsible for flushing the PWC.
460 *
461 * When page tables are being unmapped/freed as part of page fault path
462 * (full == false), valid ptes are generally not expected; however, there
463 * is one situation where they arise, which is when dirty page logging is
464 * turned off for a memslot while the VM is running. The new memslot
465 * becomes visible to page faults before the memslot commit function
466 * gets to flush the memslot, which can lead to a 2MB page mapping being
467 * installed for a guest physical address where there are already 64kB
468 * (or 4kB) mappings (of sub-pages of the same 2MB page).
469 */
kvmppc_unmap_free_pte(struct kvm * kvm,pte_t * pte,bool full,unsigned int lpid)470 static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full,
471 unsigned int lpid)
472 {
473 if (full) {
474 memset(pte, 0, sizeof(long) << RADIX_PTE_INDEX_SIZE);
475 } else {
476 pte_t *p = pte;
477 unsigned long it;
478
479 for (it = 0; it < PTRS_PER_PTE; ++it, ++p) {
480 if (pte_val(*p) == 0)
481 continue;
482 kvmppc_unmap_pte(kvm, p,
483 pte_pfn(*p) << PAGE_SHIFT,
484 PAGE_SHIFT, NULL, lpid);
485 }
486 }
487
488 kvmppc_pte_free(pte);
489 }
490
kvmppc_unmap_free_pmd(struct kvm * kvm,pmd_t * pmd,bool full,unsigned int lpid)491 static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
492 unsigned int lpid)
493 {
494 unsigned long im;
495 pmd_t *p = pmd;
496
497 for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
498 if (!pmd_present(*p))
499 continue;
500 if (pmd_is_leaf(*p)) {
501 if (full) {
502 pmd_clear(p);
503 } else {
504 WARN_ON_ONCE(1);
505 kvmppc_unmap_pte(kvm, (pte_t *)p,
506 pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
507 PMD_SHIFT, NULL, lpid);
508 }
509 } else {
510 pte_t *pte;
511
512 pte = pte_offset_map(p, 0);
513 kvmppc_unmap_free_pte(kvm, pte, full, lpid);
514 pmd_clear(p);
515 }
516 }
517 kvmppc_pmd_free(pmd);
518 }
519
kvmppc_unmap_free_pud(struct kvm * kvm,pud_t * pud,unsigned int lpid)520 static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud,
521 unsigned int lpid)
522 {
523 unsigned long iu;
524 pud_t *p = pud;
525
526 for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) {
527 if (!pud_present(*p))
528 continue;
529 if (pud_is_leaf(*p)) {
530 pud_clear(p);
531 } else {
532 pmd_t *pmd;
533
534 pmd = pmd_offset(p, 0);
535 kvmppc_unmap_free_pmd(kvm, pmd, true, lpid);
536 pud_clear(p);
537 }
538 }
539 pud_free(kvm->mm, pud);
540 }
541
kvmppc_free_pgtable_radix(struct kvm * kvm,pgd_t * pgd,unsigned int lpid)542 void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, unsigned int lpid)
543 {
544 unsigned long ig;
545
546 for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
547 p4d_t *p4d = p4d_offset(pgd, 0);
548 pud_t *pud;
549
550 if (!p4d_present(*p4d))
551 continue;
552 pud = pud_offset(p4d, 0);
553 kvmppc_unmap_free_pud(kvm, pud, lpid);
554 p4d_clear(p4d);
555 }
556 }
557
kvmppc_free_radix(struct kvm * kvm)558 void kvmppc_free_radix(struct kvm *kvm)
559 {
560 if (kvm->arch.pgtable) {
561 kvmppc_free_pgtable_radix(kvm, kvm->arch.pgtable,
562 kvm->arch.lpid);
563 pgd_free(kvm->mm, kvm->arch.pgtable);
564 kvm->arch.pgtable = NULL;
565 }
566 }
567
kvmppc_unmap_free_pmd_entry_table(struct kvm * kvm,pmd_t * pmd,unsigned long gpa,unsigned int lpid)568 static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd,
569 unsigned long gpa, unsigned int lpid)
570 {
571 pte_t *pte = pte_offset_kernel(pmd, 0);
572
573 /*
574 * Clearing the pmd entry then flushing the PWC ensures that the pte
575 * page no longer be cached by the MMU, so can be freed without
576 * flushing the PWC again.
577 */
578 pmd_clear(pmd);
579 kvmppc_radix_flush_pwc(kvm, lpid);
580
581 kvmppc_unmap_free_pte(kvm, pte, false, lpid);
582 }
583
kvmppc_unmap_free_pud_entry_table(struct kvm * kvm,pud_t * pud,unsigned long gpa,unsigned int lpid)584 static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
585 unsigned long gpa, unsigned int lpid)
586 {
587 pmd_t *pmd = pmd_offset(pud, 0);
588
589 /*
590 * Clearing the pud entry then flushing the PWC ensures that the pmd
591 * page and any children pte pages will no longer be cached by the MMU,
592 * so can be freed without flushing the PWC again.
593 */
594 pud_clear(pud);
595 kvmppc_radix_flush_pwc(kvm, lpid);
596
597 kvmppc_unmap_free_pmd(kvm, pmd, false, lpid);
598 }
599
600 /*
601 * There are a number of bits which may differ between different faults to
602 * the same partition scope entry. RC bits, in the course of cleaning and
603 * aging. And the write bit can change, either the access could have been
604 * upgraded, or a read fault could happen concurrently with a write fault
605 * that sets those bits first.
606 */
607 #define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED))
608
kvmppc_create_pte(struct kvm * kvm,pgd_t * pgtable,pte_t pte,unsigned long gpa,unsigned int level,unsigned long mmu_seq,unsigned int lpid,unsigned long * rmapp,struct rmap_nested ** n_rmap)609 int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
610 unsigned long gpa, unsigned int level,
611 unsigned long mmu_seq, unsigned int lpid,
612 unsigned long *rmapp, struct rmap_nested **n_rmap)
613 {
614 pgd_t *pgd;
615 p4d_t *p4d;
616 pud_t *pud, *new_pud = NULL;
617 pmd_t *pmd, *new_pmd = NULL;
618 pte_t *ptep, *new_ptep = NULL;
619 int ret;
620
621 /* Traverse the guest's 2nd-level tree, allocate new levels needed */
622 pgd = pgtable + pgd_index(gpa);
623 p4d = p4d_offset(pgd, gpa);
624
625 pud = NULL;
626 if (p4d_present(*p4d))
627 pud = pud_offset(p4d, gpa);
628 else
629 new_pud = pud_alloc_one(kvm->mm, gpa);
630
631 pmd = NULL;
632 if (pud && pud_present(*pud) && !pud_is_leaf(*pud))
633 pmd = pmd_offset(pud, gpa);
634 else if (level <= 1)
635 new_pmd = kvmppc_pmd_alloc();
636
637 if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
638 new_ptep = kvmppc_pte_alloc();
639
640 /* Check if we might have been invalidated; let the guest retry if so */
641 spin_lock(&kvm->mmu_lock);
642 ret = -EAGAIN;
643 if (mmu_invalidate_retry(kvm, mmu_seq))
644 goto out_unlock;
645
646 /* Now traverse again under the lock and change the tree */
647 ret = -ENOMEM;
648 if (p4d_none(*p4d)) {
649 if (!new_pud)
650 goto out_unlock;
651 p4d_populate(kvm->mm, p4d, new_pud);
652 new_pud = NULL;
653 }
654 pud = pud_offset(p4d, gpa);
655 if (pud_is_leaf(*pud)) {
656 unsigned long hgpa = gpa & PUD_MASK;
657
658 /* Check if we raced and someone else has set the same thing */
659 if (level == 2) {
660 if (pud_raw(*pud) == pte_raw(pte)) {
661 ret = 0;
662 goto out_unlock;
663 }
664 /* Valid 1GB page here already, add our extra bits */
665 WARN_ON_ONCE((pud_val(*pud) ^ pte_val(pte)) &
666 PTE_BITS_MUST_MATCH);
667 kvmppc_radix_update_pte(kvm, (pte_t *)pud,
668 0, pte_val(pte), hgpa, PUD_SHIFT);
669 ret = 0;
670 goto out_unlock;
671 }
672 /*
673 * If we raced with another CPU which has just put
674 * a 1GB pte in after we saw a pmd page, try again.
675 */
676 if (!new_pmd) {
677 ret = -EAGAIN;
678 goto out_unlock;
679 }
680 /* Valid 1GB page here already, remove it */
681 kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL,
682 lpid);
683 }
684 if (level == 2) {
685 if (!pud_none(*pud)) {
686 /*
687 * There's a page table page here, but we wanted to
688 * install a large page, so remove and free the page
689 * table page.
690 */
691 kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa, lpid);
692 }
693 kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte);
694 if (rmapp && n_rmap)
695 kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
696 ret = 0;
697 goto out_unlock;
698 }
699 if (pud_none(*pud)) {
700 if (!new_pmd)
701 goto out_unlock;
702 pud_populate(kvm->mm, pud, new_pmd);
703 new_pmd = NULL;
704 }
705 pmd = pmd_offset(pud, gpa);
706 if (pmd_is_leaf(*pmd)) {
707 unsigned long lgpa = gpa & PMD_MASK;
708
709 /* Check if we raced and someone else has set the same thing */
710 if (level == 1) {
711 if (pmd_raw(*pmd) == pte_raw(pte)) {
712 ret = 0;
713 goto out_unlock;
714 }
715 /* Valid 2MB page here already, add our extra bits */
716 WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) &
717 PTE_BITS_MUST_MATCH);
718 kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd),
719 0, pte_val(pte), lgpa, PMD_SHIFT);
720 ret = 0;
721 goto out_unlock;
722 }
723
724 /*
725 * If we raced with another CPU which has just put
726 * a 2MB pte in after we saw a pte page, try again.
727 */
728 if (!new_ptep) {
729 ret = -EAGAIN;
730 goto out_unlock;
731 }
732 /* Valid 2MB page here already, remove it */
733 kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL,
734 lpid);
735 }
736 if (level == 1) {
737 if (!pmd_none(*pmd)) {
738 /*
739 * There's a page table page here, but we wanted to
740 * install a large page, so remove and free the page
741 * table page.
742 */
743 kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa, lpid);
744 }
745 kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
746 if (rmapp && n_rmap)
747 kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
748 ret = 0;
749 goto out_unlock;
750 }
751 if (pmd_none(*pmd)) {
752 if (!new_ptep)
753 goto out_unlock;
754 pmd_populate(kvm->mm, pmd, new_ptep);
755 new_ptep = NULL;
756 }
757 ptep = pte_offset_kernel(pmd, gpa);
758 if (pte_present(*ptep)) {
759 /* Check if someone else set the same thing */
760 if (pte_raw(*ptep) == pte_raw(pte)) {
761 ret = 0;
762 goto out_unlock;
763 }
764 /* Valid page here already, add our extra bits */
765 WARN_ON_ONCE((pte_val(*ptep) ^ pte_val(pte)) &
766 PTE_BITS_MUST_MATCH);
767 kvmppc_radix_update_pte(kvm, ptep, 0, pte_val(pte), gpa, 0);
768 ret = 0;
769 goto out_unlock;
770 }
771 kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte);
772 if (rmapp && n_rmap)
773 kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
774 ret = 0;
775
776 out_unlock:
777 spin_unlock(&kvm->mmu_lock);
778 if (new_pud)
779 pud_free(kvm->mm, new_pud);
780 if (new_pmd)
781 kvmppc_pmd_free(new_pmd);
782 if (new_ptep)
783 kvmppc_pte_free(new_ptep);
784 return ret;
785 }
786
kvmppc_hv_handle_set_rc(struct kvm * kvm,bool nested,bool writing,unsigned long gpa,unsigned int lpid)787 bool kvmppc_hv_handle_set_rc(struct kvm *kvm, bool nested, bool writing,
788 unsigned long gpa, unsigned int lpid)
789 {
790 unsigned long pgflags;
791 unsigned int shift;
792 pte_t *ptep;
793
794 /*
795 * Need to set an R or C bit in the 2nd-level tables;
796 * since we are just helping out the hardware here,
797 * it is sufficient to do what the hardware does.
798 */
799 pgflags = _PAGE_ACCESSED;
800 if (writing)
801 pgflags |= _PAGE_DIRTY;
802
803 if (nested)
804 ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
805 else
806 ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
807
808 if (ptep && pte_present(*ptep) && (!writing || pte_write(*ptep))) {
809 kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, gpa, shift);
810 return true;
811 }
812 return false;
813 }
814
kvmppc_book3s_instantiate_page(struct kvm_vcpu * vcpu,unsigned long gpa,struct kvm_memory_slot * memslot,bool writing,bool kvm_ro,pte_t * inserted_pte,unsigned int * levelp)815 int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
816 unsigned long gpa,
817 struct kvm_memory_slot *memslot,
818 bool writing, bool kvm_ro,
819 pte_t *inserted_pte, unsigned int *levelp)
820 {
821 struct kvm *kvm = vcpu->kvm;
822 struct page *page = NULL;
823 unsigned long mmu_seq;
824 unsigned long hva, gfn = gpa >> PAGE_SHIFT;
825 bool upgrade_write = false;
826 bool *upgrade_p = &upgrade_write;
827 pte_t pte, *ptep;
828 unsigned int shift, level;
829 int ret;
830 bool large_enable;
831
832 /* used to check for invalidations in progress */
833 mmu_seq = kvm->mmu_invalidate_seq;
834 smp_rmb();
835
836 /*
837 * Do a fast check first, since __gfn_to_pfn_memslot doesn't
838 * do it with !atomic && !async, which is how we call it.
839 * We always ask for write permission since the common case
840 * is that the page is writable.
841 */
842 hva = gfn_to_hva_memslot(memslot, gfn);
843 if (!kvm_ro && get_user_page_fast_only(hva, FOLL_WRITE, &page)) {
844 upgrade_write = true;
845 } else {
846 unsigned long pfn;
847
848 /* Call KVM generic code to do the slow-path check */
849 pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL,
850 writing, upgrade_p, NULL);
851 if (is_error_noslot_pfn(pfn))
852 return -EFAULT;
853 page = NULL;
854 if (pfn_valid(pfn)) {
855 page = pfn_to_page(pfn);
856 if (PageReserved(page))
857 page = NULL;
858 }
859 }
860
861 /*
862 * Read the PTE from the process' radix tree and use that
863 * so we get the shift and attribute bits.
864 */
865 spin_lock(&kvm->mmu_lock);
866 ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &shift);
867 pte = __pte(0);
868 if (ptep)
869 pte = READ_ONCE(*ptep);
870 spin_unlock(&kvm->mmu_lock);
871 /*
872 * If the PTE disappeared temporarily due to a THP
873 * collapse, just return and let the guest try again.
874 */
875 if (!pte_present(pte)) {
876 if (page)
877 put_page(page);
878 return RESUME_GUEST;
879 }
880
881 /* If we're logging dirty pages, always map single pages */
882 large_enable = !(memslot->flags & KVM_MEM_LOG_DIRTY_PAGES);
883
884 /* Get pte level from shift/size */
885 if (large_enable && shift == PUD_SHIFT &&
886 (gpa & (PUD_SIZE - PAGE_SIZE)) ==
887 (hva & (PUD_SIZE - PAGE_SIZE))) {
888 level = 2;
889 } else if (large_enable && shift == PMD_SHIFT &&
890 (gpa & (PMD_SIZE - PAGE_SIZE)) ==
891 (hva & (PMD_SIZE - PAGE_SIZE))) {
892 level = 1;
893 } else {
894 level = 0;
895 if (shift > PAGE_SHIFT) {
896 /*
897 * If the pte maps more than one page, bring over
898 * bits from the virtual address to get the real
899 * address of the specific single page we want.
900 */
901 unsigned long rpnmask = (1ul << shift) - PAGE_SIZE;
902 pte = __pte(pte_val(pte) | (hva & rpnmask));
903 }
904 }
905
906 pte = __pte(pte_val(pte) | _PAGE_EXEC | _PAGE_ACCESSED);
907 if (writing || upgrade_write) {
908 if (pte_val(pte) & _PAGE_WRITE)
909 pte = __pte(pte_val(pte) | _PAGE_DIRTY);
910 } else {
911 pte = __pte(pte_val(pte) & ~(_PAGE_WRITE | _PAGE_DIRTY));
912 }
913
914 /* Allocate space in the tree and write the PTE */
915 ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level,
916 mmu_seq, kvm->arch.lpid, NULL, NULL);
917 if (inserted_pte)
918 *inserted_pte = pte;
919 if (levelp)
920 *levelp = level;
921
922 if (page) {
923 if (!ret && (pte_val(pte) & _PAGE_WRITE))
924 set_page_dirty_lock(page);
925 put_page(page);
926 }
927
928 /* Increment number of large pages if we (successfully) inserted one */
929 if (!ret) {
930 if (level == 1)
931 kvm->stat.num_2M_pages++;
932 else if (level == 2)
933 kvm->stat.num_1G_pages++;
934 }
935
936 return ret;
937 }
938
kvmppc_book3s_radix_page_fault(struct kvm_vcpu * vcpu,unsigned long ea,unsigned long dsisr)939 int kvmppc_book3s_radix_page_fault(struct kvm_vcpu *vcpu,
940 unsigned long ea, unsigned long dsisr)
941 {
942 struct kvm *kvm = vcpu->kvm;
943 unsigned long gpa, gfn;
944 struct kvm_memory_slot *memslot;
945 long ret;
946 bool writing = !!(dsisr & DSISR_ISSTORE);
947 bool kvm_ro = false;
948
949 /* Check for unusual errors */
950 if (dsisr & DSISR_UNSUPP_MMU) {
951 pr_err("KVM: Got unsupported MMU fault\n");
952 return -EFAULT;
953 }
954 if (dsisr & DSISR_BADACCESS) {
955 /* Reflect to the guest as DSI */
956 pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
957 kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
958 return RESUME_GUEST;
959 }
960
961 /* Translate the logical address */
962 gpa = vcpu->arch.fault_gpa & ~0xfffUL;
963 gpa &= ~0xF000000000000000ul;
964 gfn = gpa >> PAGE_SHIFT;
965 if (!(dsisr & DSISR_PRTABLE_FAULT))
966 gpa |= ea & 0xfff;
967
968 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
969 return kvmppc_send_page_to_uv(kvm, gfn);
970
971 /* Get the corresponding memslot */
972 memslot = gfn_to_memslot(kvm, gfn);
973
974 /* No memslot means it's an emulated MMIO region */
975 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
976 if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
977 DSISR_SET_RC)) {
978 /*
979 * Bad address in guest page table tree, or other
980 * unusual error - reflect it to the guest as DSI.
981 */
982 kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
983 return RESUME_GUEST;
984 }
985 return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
986 }
987
988 if (memslot->flags & KVM_MEM_READONLY) {
989 if (writing) {
990 /* give the guest a DSI */
991 kvmppc_core_queue_data_storage(vcpu, ea, DSISR_ISSTORE |
992 DSISR_PROTFAULT);
993 return RESUME_GUEST;
994 }
995 kvm_ro = true;
996 }
997
998 /* Failed to set the reference/change bits */
999 if (dsisr & DSISR_SET_RC) {
1000 spin_lock(&kvm->mmu_lock);
1001 if (kvmppc_hv_handle_set_rc(kvm, false, writing,
1002 gpa, kvm->arch.lpid))
1003 dsisr &= ~DSISR_SET_RC;
1004 spin_unlock(&kvm->mmu_lock);
1005
1006 if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
1007 DSISR_PROTFAULT | DSISR_SET_RC)))
1008 return RESUME_GUEST;
1009 }
1010
1011 /* Try to insert a pte */
1012 ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, writing,
1013 kvm_ro, NULL, NULL);
1014
1015 if (ret == 0 || ret == -EAGAIN)
1016 ret = RESUME_GUEST;
1017 return ret;
1018 }
1019
1020 /* Called with kvm->mmu_lock held */
kvm_unmap_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)1021 void kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1022 unsigned long gfn)
1023 {
1024 pte_t *ptep;
1025 unsigned long gpa = gfn << PAGE_SHIFT;
1026 unsigned int shift;
1027
1028 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) {
1029 uv_page_inval(kvm->arch.lpid, gpa, PAGE_SHIFT);
1030 return;
1031 }
1032
1033 ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1034 if (ptep && pte_present(*ptep))
1035 kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
1036 kvm->arch.lpid);
1037 }
1038
1039 /* Called with kvm->mmu_lock held */
kvm_age_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)1040 bool kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1041 unsigned long gfn)
1042 {
1043 pte_t *ptep;
1044 unsigned long gpa = gfn << PAGE_SHIFT;
1045 unsigned int shift;
1046 bool ref = false;
1047 unsigned long old, *rmapp;
1048
1049 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1050 return ref;
1051
1052 ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1053 if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
1054 old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
1055 gpa, shift);
1056 /* XXX need to flush tlb here? */
1057 /* Also clear bit in ptes in shadow pgtable for nested guests */
1058 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1059 kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_ACCESSED, 0,
1060 old & PTE_RPN_MASK,
1061 1UL << shift);
1062 ref = true;
1063 }
1064 return ref;
1065 }
1066
1067 /* Called with kvm->mmu_lock held */
kvm_test_age_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)1068 bool kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1069 unsigned long gfn)
1070
1071 {
1072 pte_t *ptep;
1073 unsigned long gpa = gfn << PAGE_SHIFT;
1074 unsigned int shift;
1075 bool ref = false;
1076
1077 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1078 return ref;
1079
1080 ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1081 if (ptep && pte_present(*ptep) && pte_young(*ptep))
1082 ref = true;
1083 return ref;
1084 }
1085
1086 /* Returns the number of PAGE_SIZE pages that are dirty */
kvm_radix_test_clear_dirty(struct kvm * kvm,struct kvm_memory_slot * memslot,int pagenum)1087 static int kvm_radix_test_clear_dirty(struct kvm *kvm,
1088 struct kvm_memory_slot *memslot, int pagenum)
1089 {
1090 unsigned long gfn = memslot->base_gfn + pagenum;
1091 unsigned long gpa = gfn << PAGE_SHIFT;
1092 pte_t *ptep, pte;
1093 unsigned int shift;
1094 int ret = 0;
1095 unsigned long old, *rmapp;
1096
1097 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1098 return ret;
1099
1100 /*
1101 * For performance reasons we don't hold kvm->mmu_lock while walking the
1102 * partition scoped table.
1103 */
1104 ptep = find_kvm_secondary_pte_unlocked(kvm, gpa, &shift);
1105 if (!ptep)
1106 return 0;
1107
1108 pte = READ_ONCE(*ptep);
1109 if (pte_present(pte) && pte_dirty(pte)) {
1110 spin_lock(&kvm->mmu_lock);
1111 /*
1112 * Recheck the pte again
1113 */
1114 if (pte_val(pte) != pte_val(*ptep)) {
1115 /*
1116 * We have KVM_MEM_LOG_DIRTY_PAGES enabled. Hence we can
1117 * only find PAGE_SIZE pte entries here. We can continue
1118 * to use the pte addr returned by above page table
1119 * walk.
1120 */
1121 if (!pte_present(*ptep) || !pte_dirty(*ptep)) {
1122 spin_unlock(&kvm->mmu_lock);
1123 return 0;
1124 }
1125 }
1126
1127 ret = 1;
1128 VM_BUG_ON(shift);
1129 old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,
1130 gpa, shift);
1131 kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid);
1132 /* Also clear bit in ptes in shadow pgtable for nested guests */
1133 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1134 kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_DIRTY, 0,
1135 old & PTE_RPN_MASK,
1136 1UL << shift);
1137 spin_unlock(&kvm->mmu_lock);
1138 }
1139 return ret;
1140 }
1141
kvmppc_hv_get_dirty_log_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long * map)1142 long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm,
1143 struct kvm_memory_slot *memslot, unsigned long *map)
1144 {
1145 unsigned long i, j;
1146 int npages;
1147
1148 for (i = 0; i < memslot->npages; i = j) {
1149 npages = kvm_radix_test_clear_dirty(kvm, memslot, i);
1150
1151 /*
1152 * Note that if npages > 0 then i must be a multiple of npages,
1153 * since huge pages are only used to back the guest at guest
1154 * real addresses that are a multiple of their size.
1155 * Since we have at most one PTE covering any given guest
1156 * real address, if npages > 1 we can skip to i + npages.
1157 */
1158 j = i + 1;
1159 if (npages) {
1160 set_dirty_bits(map, i, npages);
1161 j = i + npages;
1162 }
1163 }
1164 return 0;
1165 }
1166
kvmppc_radix_flush_memslot(struct kvm * kvm,const struct kvm_memory_slot * memslot)1167 void kvmppc_radix_flush_memslot(struct kvm *kvm,
1168 const struct kvm_memory_slot *memslot)
1169 {
1170 unsigned long n;
1171 pte_t *ptep;
1172 unsigned long gpa;
1173 unsigned int shift;
1174
1175 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)
1176 kvmppc_uvmem_drop_pages(memslot, kvm, true);
1177
1178 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1179 return;
1180
1181 gpa = memslot->base_gfn << PAGE_SHIFT;
1182 spin_lock(&kvm->mmu_lock);
1183 for (n = memslot->npages; n; --n) {
1184 ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1185 if (ptep && pte_present(*ptep))
1186 kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
1187 kvm->arch.lpid);
1188 gpa += PAGE_SIZE;
1189 }
1190 /*
1191 * Increase the mmu notifier sequence number to prevent any page
1192 * fault that read the memslot earlier from writing a PTE.
1193 */
1194 kvm->mmu_invalidate_seq++;
1195 spin_unlock(&kvm->mmu_lock);
1196 }
1197
add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info * info,int psize,int * indexp)1198 static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info,
1199 int psize, int *indexp)
1200 {
1201 if (!mmu_psize_defs[psize].shift)
1202 return;
1203 info->ap_encodings[*indexp] = mmu_psize_defs[psize].shift |
1204 (mmu_psize_defs[psize].ap << 29);
1205 ++(*indexp);
1206 }
1207
kvmhv_get_rmmu_info(struct kvm * kvm,struct kvm_ppc_rmmu_info * info)1208 int kvmhv_get_rmmu_info(struct kvm *kvm, struct kvm_ppc_rmmu_info *info)
1209 {
1210 int i;
1211
1212 if (!radix_enabled())
1213 return -EINVAL;
1214 memset(info, 0, sizeof(*info));
1215
1216 /* 4k page size */
1217 info->geometries[0].page_shift = 12;
1218 info->geometries[0].level_bits[0] = 9;
1219 for (i = 1; i < 4; ++i)
1220 info->geometries[0].level_bits[i] = p9_supported_radix_bits[i];
1221 /* 64k page size */
1222 info->geometries[1].page_shift = 16;
1223 for (i = 0; i < 4; ++i)
1224 info->geometries[1].level_bits[i] = p9_supported_radix_bits[i];
1225
1226 i = 0;
1227 add_rmmu_ap_encoding(info, MMU_PAGE_4K, &i);
1228 add_rmmu_ap_encoding(info, MMU_PAGE_64K, &i);
1229 add_rmmu_ap_encoding(info, MMU_PAGE_2M, &i);
1230 add_rmmu_ap_encoding(info, MMU_PAGE_1G, &i);
1231
1232 return 0;
1233 }
1234
kvmppc_init_vm_radix(struct kvm * kvm)1235 int kvmppc_init_vm_radix(struct kvm *kvm)
1236 {
1237 kvm->arch.pgtable = pgd_alloc(kvm->mm);
1238 if (!kvm->arch.pgtable)
1239 return -ENOMEM;
1240 return 0;
1241 }
1242
pte_ctor(void * addr)1243 static void pte_ctor(void *addr)
1244 {
1245 memset(addr, 0, RADIX_PTE_TABLE_SIZE);
1246 }
1247
pmd_ctor(void * addr)1248 static void pmd_ctor(void *addr)
1249 {
1250 memset(addr, 0, RADIX_PMD_TABLE_SIZE);
1251 }
1252
1253 struct debugfs_radix_state {
1254 struct kvm *kvm;
1255 struct mutex mutex;
1256 unsigned long gpa;
1257 int lpid;
1258 int chars_left;
1259 int buf_index;
1260 char buf[128];
1261 u8 hdr;
1262 };
1263
debugfs_radix_open(struct inode * inode,struct file * file)1264 static int debugfs_radix_open(struct inode *inode, struct file *file)
1265 {
1266 struct kvm *kvm = inode->i_private;
1267 struct debugfs_radix_state *p;
1268
1269 p = kzalloc(sizeof(*p), GFP_KERNEL);
1270 if (!p)
1271 return -ENOMEM;
1272
1273 kvm_get_kvm(kvm);
1274 p->kvm = kvm;
1275 mutex_init(&p->mutex);
1276 file->private_data = p;
1277
1278 return nonseekable_open(inode, file);
1279 }
1280
debugfs_radix_release(struct inode * inode,struct file * file)1281 static int debugfs_radix_release(struct inode *inode, struct file *file)
1282 {
1283 struct debugfs_radix_state *p = file->private_data;
1284
1285 kvm_put_kvm(p->kvm);
1286 kfree(p);
1287 return 0;
1288 }
1289
debugfs_radix_read(struct file * file,char __user * buf,size_t len,loff_t * ppos)1290 static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
1291 size_t len, loff_t *ppos)
1292 {
1293 struct debugfs_radix_state *p = file->private_data;
1294 ssize_t ret, r;
1295 unsigned long n;
1296 struct kvm *kvm;
1297 unsigned long gpa;
1298 pgd_t *pgt;
1299 struct kvm_nested_guest *nested;
1300 pgd_t *pgdp;
1301 p4d_t p4d, *p4dp;
1302 pud_t pud, *pudp;
1303 pmd_t pmd, *pmdp;
1304 pte_t *ptep;
1305 int shift;
1306 unsigned long pte;
1307
1308 kvm = p->kvm;
1309 if (!kvm_is_radix(kvm))
1310 return 0;
1311
1312 ret = mutex_lock_interruptible(&p->mutex);
1313 if (ret)
1314 return ret;
1315
1316 if (p->chars_left) {
1317 n = p->chars_left;
1318 if (n > len)
1319 n = len;
1320 r = copy_to_user(buf, p->buf + p->buf_index, n);
1321 n -= r;
1322 p->chars_left -= n;
1323 p->buf_index += n;
1324 buf += n;
1325 len -= n;
1326 ret = n;
1327 if (r) {
1328 if (!n)
1329 ret = -EFAULT;
1330 goto out;
1331 }
1332 }
1333
1334 gpa = p->gpa;
1335 nested = NULL;
1336 pgt = NULL;
1337 while (len != 0 && p->lpid >= 0) {
1338 if (gpa >= RADIX_PGTABLE_RANGE) {
1339 gpa = 0;
1340 pgt = NULL;
1341 if (nested) {
1342 kvmhv_put_nested(nested);
1343 nested = NULL;
1344 }
1345 p->lpid = kvmhv_nested_next_lpid(kvm, p->lpid);
1346 p->hdr = 0;
1347 if (p->lpid < 0)
1348 break;
1349 }
1350 if (!pgt) {
1351 if (p->lpid == 0) {
1352 pgt = kvm->arch.pgtable;
1353 } else {
1354 nested = kvmhv_get_nested(kvm, p->lpid, false);
1355 if (!nested) {
1356 gpa = RADIX_PGTABLE_RANGE;
1357 continue;
1358 }
1359 pgt = nested->shadow_pgtable;
1360 }
1361 }
1362 n = 0;
1363 if (!p->hdr) {
1364 if (p->lpid > 0)
1365 n = scnprintf(p->buf, sizeof(p->buf),
1366 "\nNested LPID %d: ", p->lpid);
1367 n += scnprintf(p->buf + n, sizeof(p->buf) - n,
1368 "pgdir: %lx\n", (unsigned long)pgt);
1369 p->hdr = 1;
1370 goto copy;
1371 }
1372
1373 pgdp = pgt + pgd_index(gpa);
1374 p4dp = p4d_offset(pgdp, gpa);
1375 p4d = READ_ONCE(*p4dp);
1376 if (!(p4d_val(p4d) & _PAGE_PRESENT)) {
1377 gpa = (gpa & P4D_MASK) + P4D_SIZE;
1378 continue;
1379 }
1380
1381 pudp = pud_offset(&p4d, gpa);
1382 pud = READ_ONCE(*pudp);
1383 if (!(pud_val(pud) & _PAGE_PRESENT)) {
1384 gpa = (gpa & PUD_MASK) + PUD_SIZE;
1385 continue;
1386 }
1387 if (pud_val(pud) & _PAGE_PTE) {
1388 pte = pud_val(pud);
1389 shift = PUD_SHIFT;
1390 goto leaf;
1391 }
1392
1393 pmdp = pmd_offset(&pud, gpa);
1394 pmd = READ_ONCE(*pmdp);
1395 if (!(pmd_val(pmd) & _PAGE_PRESENT)) {
1396 gpa = (gpa & PMD_MASK) + PMD_SIZE;
1397 continue;
1398 }
1399 if (pmd_val(pmd) & _PAGE_PTE) {
1400 pte = pmd_val(pmd);
1401 shift = PMD_SHIFT;
1402 goto leaf;
1403 }
1404
1405 ptep = pte_offset_kernel(&pmd, gpa);
1406 pte = pte_val(READ_ONCE(*ptep));
1407 if (!(pte & _PAGE_PRESENT)) {
1408 gpa += PAGE_SIZE;
1409 continue;
1410 }
1411 shift = PAGE_SHIFT;
1412 leaf:
1413 n = scnprintf(p->buf, sizeof(p->buf),
1414 " %lx: %lx %d\n", gpa, pte, shift);
1415 gpa += 1ul << shift;
1416 copy:
1417 p->chars_left = n;
1418 if (n > len)
1419 n = len;
1420 r = copy_to_user(buf, p->buf, n);
1421 n -= r;
1422 p->chars_left -= n;
1423 p->buf_index = n;
1424 buf += n;
1425 len -= n;
1426 ret += n;
1427 if (r) {
1428 if (!ret)
1429 ret = -EFAULT;
1430 break;
1431 }
1432 }
1433 p->gpa = gpa;
1434 if (nested)
1435 kvmhv_put_nested(nested);
1436
1437 out:
1438 mutex_unlock(&p->mutex);
1439 return ret;
1440 }
1441
debugfs_radix_write(struct file * file,const char __user * buf,size_t len,loff_t * ppos)1442 static ssize_t debugfs_radix_write(struct file *file, const char __user *buf,
1443 size_t len, loff_t *ppos)
1444 {
1445 return -EACCES;
1446 }
1447
1448 static const struct file_operations debugfs_radix_fops = {
1449 .owner = THIS_MODULE,
1450 .open = debugfs_radix_open,
1451 .release = debugfs_radix_release,
1452 .read = debugfs_radix_read,
1453 .write = debugfs_radix_write,
1454 .llseek = generic_file_llseek,
1455 };
1456
kvmhv_radix_debugfs_init(struct kvm * kvm)1457 void kvmhv_radix_debugfs_init(struct kvm *kvm)
1458 {
1459 debugfs_create_file("radix", 0400, kvm->debugfs_dentry, kvm,
1460 &debugfs_radix_fops);
1461 }
1462
kvmppc_radix_init(void)1463 int kvmppc_radix_init(void)
1464 {
1465 unsigned long size = sizeof(void *) << RADIX_PTE_INDEX_SIZE;
1466
1467 kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, 0, pte_ctor);
1468 if (!kvm_pte_cache)
1469 return -ENOMEM;
1470
1471 size = sizeof(void *) << RADIX_PMD_INDEX_SIZE;
1472
1473 kvm_pmd_cache = kmem_cache_create("kvm-pmd", size, size, 0, pmd_ctor);
1474 if (!kvm_pmd_cache) {
1475 kmem_cache_destroy(kvm_pte_cache);
1476 return -ENOMEM;
1477 }
1478
1479 return 0;
1480 }
1481
kvmppc_radix_exit(void)1482 void kvmppc_radix_exit(void)
1483 {
1484 kmem_cache_destroy(kvm_pte_cache);
1485 kmem_cache_destroy(kvm_pmd_cache);
1486 }
1487