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