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 "book3s_hv.h"
19 #include <asm/page.h>
20 #include <asm/mmu.h>
21 #include <asm/pgalloc.h>
22 #include <asm/pte-walk.h>
23 #include <asm/ultravisor.h>
24 #include <asm/kvm_book3s_uvmem.h>
25 #include <asm/plpar_wrappers.h>
26 #include <asm/firmware.h>
27
28 /*
29 * Supported radix tree geometry.
30 * Like p9, we support either 5 or 9 bits at the first (lowest) level,
31 * for a page size of 64k or 4k.
32 */
33 static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
34
__kvmhv_copy_tofrom_guest_radix(int lpid,int pid,gva_t eaddr,void * to,void * from,unsigned long n)35 unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
36 gva_t eaddr, void *to, void *from,
37 unsigned long n)
38 {
39 int old_pid, old_lpid;
40 unsigned long quadrant, ret = n;
41 bool is_load = !!to;
42
43 if (kvmhv_is_nestedv2())
44 return H_UNSUPPORTED;
45
46 /* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */
47 if (kvmhv_on_pseries())
48 return plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr,
49 (to != NULL) ? __pa(to): 0,
50 (from != NULL) ? __pa(from): 0, n);
51
52 if (eaddr & (0xFFFUL << 52))
53 return ret;
54
55 quadrant = 1;
56 if (!pid)
57 quadrant = 2;
58 if (is_load)
59 from = (void *) (eaddr | (quadrant << 62));
60 else
61 to = (void *) (eaddr | (quadrant << 62));
62
63 preempt_disable();
64
65 asm volatile("hwsync" ::: "memory");
66 isync();
67 /* switch the lpid first to avoid running host with unallocated pid */
68 old_lpid = mfspr(SPRN_LPID);
69 if (old_lpid != lpid)
70 mtspr(SPRN_LPID, lpid);
71 if (quadrant == 1) {
72 old_pid = mfspr(SPRN_PID);
73 if (old_pid != pid)
74 mtspr(SPRN_PID, pid);
75 }
76 isync();
77
78 pagefault_disable();
79 if (is_load)
80 ret = __copy_from_user_inatomic(to, (const void __user *)from, n);
81 else
82 ret = __copy_to_user_inatomic((void __user *)to, from, n);
83 pagefault_enable();
84
85 asm volatile("hwsync" ::: "memory");
86 isync();
87 /* switch the pid first to avoid running host with unallocated pid */
88 if (quadrant == 1 && pid != old_pid)
89 mtspr(SPRN_PID, old_pid);
90 if (lpid != old_lpid)
91 mtspr(SPRN_LPID, old_lpid);
92 isync();
93
94 preempt_enable();
95
96 return ret;
97 }
98
kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu * vcpu,gva_t eaddr,void * to,void * from,unsigned long n)99 static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
100 void *to, void *from, unsigned long n)
101 {
102 int lpid = vcpu->kvm->arch.lpid;
103 int pid;
104
105 /* This would cause a data segment intr so don't allow the access */
106 if (eaddr & (0x3FFUL << 52))
107 return -EINVAL;
108
109 /* Should we be using the nested lpid */
110 if (vcpu->arch.nested)
111 lpid = vcpu->arch.nested->shadow_lpid;
112
113 /* If accessing quadrant 3 then pid is expected to be 0 */
114 if (((eaddr >> 62) & 0x3) == 0x3)
115 pid = 0;
116 else
117 pid = kvmppc_get_pid(vcpu);
118
119 eaddr &= ~(0xFFFUL << 52);
120
121 return __kvmhv_copy_tofrom_guest_radix(lpid, pid, eaddr, to, from, n);
122 }
123
kvmhv_copy_from_guest_radix(struct kvm_vcpu * vcpu,gva_t eaddr,void * to,unsigned long n)124 long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to,
125 unsigned long n)
126 {
127 long ret;
128
129 ret = kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, to, NULL, n);
130 if (ret > 0)
131 memset(to + (n - ret), 0, ret);
132
133 return ret;
134 }
135
kvmhv_copy_to_guest_radix(struct kvm_vcpu * vcpu,gva_t eaddr,void * from,unsigned long n)136 long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *from,
137 unsigned long n)
138 {
139 return kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, NULL, from, n);
140 }
141
kvmppc_mmu_walk_radix_tree(struct kvm_vcpu * vcpu,gva_t eaddr,struct kvmppc_pte * gpte,u64 root,u64 * pte_ret_p)142 int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr,
143 struct kvmppc_pte *gpte, u64 root,
144 u64 *pte_ret_p)
145 {
146 struct kvm *kvm = vcpu->kvm;
147 int ret, level, ps;
148 unsigned long rts, bits, offset, index;
149 u64 pte, base, gpa;
150 __be64 rpte;
151
152 rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
153 ((root & RTS2_MASK) >> RTS2_SHIFT);
154 bits = root & RPDS_MASK;
155 base = root & RPDB_MASK;
156
157 offset = rts + 31;
158
159 /* Current implementations only support 52-bit space */
160 if (offset != 52)
161 return -EINVAL;
162
163 /* Walk each level of the radix tree */
164 for (level = 3; level >= 0; --level) {
165 u64 addr;
166 /* Check a valid size */
167 if (level && bits != p9_supported_radix_bits[level])
168 return -EINVAL;
169 if (level == 0 && !(bits == 5 || bits == 9))
170 return -EINVAL;
171 offset -= bits;
172 index = (eaddr >> offset) & ((1UL << bits) - 1);
173 /* Check that low bits of page table base are zero */
174 if (base & ((1UL << (bits + 3)) - 1))
175 return -EINVAL;
176 /* Read the entry from guest memory */
177 addr = base + (index * sizeof(rpte));
178
179 kvm_vcpu_srcu_read_lock(vcpu);
180 ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte));
181 kvm_vcpu_srcu_read_unlock(vcpu);
182 if (ret) {
183 if (pte_ret_p)
184 *pte_ret_p = addr;
185 return ret;
186 }
187 pte = __be64_to_cpu(rpte);
188 if (!(pte & _PAGE_PRESENT))
189 return -ENOENT;
190 /* Check if a leaf entry */
191 if (pte & _PAGE_PTE)
192 break;
193 /* Get ready to walk the next level */
194 base = pte & RPDB_MASK;
195 bits = pte & RPDS_MASK;
196 }
197
198 /* Need a leaf at lowest level; 512GB pages not supported */
199 if (level < 0 || level == 3)
200 return -EINVAL;
201
202 /* We found a valid leaf PTE */
203 /* Offset is now log base 2 of the page size */
204 gpa = pte & 0x01fffffffffff000ul;
205 if (gpa & ((1ul << offset) - 1))
206 return -EINVAL;
207 gpa |= eaddr & ((1ul << offset) - 1);
208 for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps)
209 if (offset == mmu_psize_defs[ps].shift)
210 break;
211 gpte->page_size = ps;
212 gpte->page_shift = offset;
213
214 gpte->eaddr = eaddr;
215 gpte->raddr = gpa;
216
217 /* Work out permissions */
218 gpte->may_read = !!(pte & _PAGE_READ);
219 gpte->may_write = !!(pte & _PAGE_WRITE);
220 gpte->may_execute = !!(pte & _PAGE_EXEC);
221
222 gpte->rc = pte & (_PAGE_ACCESSED | _PAGE_DIRTY);
223
224 if (pte_ret_p)
225 *pte_ret_p = pte;
226
227 return 0;
228 }
229
230 /*
231 * Used to walk a partition or process table radix tree in guest memory
232 * Note: We exploit the fact that a partition table and a process
233 * table have the same layout, a partition-scoped page table and a
234 * process-scoped page table have the same layout, and the 2nd
235 * doubleword of a partition table entry has the same layout as
236 * the PTCR register.
237 */
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)238 int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
239 struct kvmppc_pte *gpte, u64 table,
240 int table_index, u64 *pte_ret_p)
241 {
242 struct kvm *kvm = vcpu->kvm;
243 int ret;
244 unsigned long size, ptbl, root;
245 struct prtb_entry entry;
246
247 if ((table & PRTS_MASK) > 24)
248 return -EINVAL;
249 size = 1ul << ((table & PRTS_MASK) + 12);
250
251 /* Is the table big enough to contain this entry? */
252 if ((table_index * sizeof(entry)) >= size)
253 return -EINVAL;
254
255 /* Read the table to find the root of the radix tree */
256 ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry));
257 kvm_vcpu_srcu_read_lock(vcpu);
258 ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry));
259 kvm_vcpu_srcu_read_unlock(vcpu);
260 if (ret)
261 return ret;
262
263 /* Root is stored in the first double word */
264 root = be64_to_cpu(entry.prtb0);
265
266 return kvmppc_mmu_walk_radix_tree(vcpu, eaddr, gpte, root, pte_ret_p);
267 }
268
kvmppc_mmu_radix_xlate(struct kvm_vcpu * vcpu,gva_t eaddr,struct kvmppc_pte * gpte,bool data,bool iswrite)269 int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
270 struct kvmppc_pte *gpte, bool data, bool iswrite)
271 {
272 u32 pid;
273 u64 pte;
274 int ret;
275
276 /* Work out effective PID */
277 switch (eaddr >> 62) {
278 case 0:
279 pid = kvmppc_get_pid(vcpu);
280 break;
281 case 3:
282 pid = 0;
283 break;
284 default:
285 return -EINVAL;
286 }
287
288 ret = kvmppc_mmu_radix_translate_table(vcpu, eaddr, gpte,
289 vcpu->kvm->arch.process_table, pid, &pte);
290 if (ret)
291 return ret;
292
293 /* Check privilege (applies only to process scoped translations) */
294 if (kvmppc_get_msr(vcpu) & MSR_PR) {
295 if (pte & _PAGE_PRIVILEGED) {
296 gpte->may_read = 0;
297 gpte->may_write = 0;
298 gpte->may_execute = 0;
299 }
300 } else {
301 if (!(pte & _PAGE_PRIVILEGED)) {
302 /* Check AMR/IAMR to see if strict mode is in force */
303 if (kvmppc_get_amr_hv(vcpu) & (1ul << 62))
304 gpte->may_read = 0;
305 if (kvmppc_get_amr_hv(vcpu) & (1ul << 63))
306 gpte->may_write = 0;
307 if (vcpu->arch.iamr & (1ul << 62))
308 gpte->may_execute = 0;
309 }
310 }
311
312 return 0;
313 }
314
kvmppc_radix_tlbie_page(struct kvm * kvm,unsigned long addr,unsigned int pshift,u64 lpid)315 void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
316 unsigned int pshift, u64 lpid)
317 {
318 unsigned long psize = PAGE_SIZE;
319 int psi;
320 long rc;
321 unsigned long rb;
322
323 if (pshift)
324 psize = 1UL << pshift;
325 else
326 pshift = PAGE_SHIFT;
327
328 addr &= ~(psize - 1);
329
330 if (!kvmhv_on_pseries()) {
331 radix__flush_tlb_lpid_page(lpid, addr, psize);
332 return;
333 }
334
335 psi = shift_to_mmu_psize(pshift);
336
337 if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE)) {
338 rb = addr | (mmu_get_ap(psi) << PPC_BITLSHIFT(58));
339 rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(0, 0, 1),
340 lpid, rb);
341 } else {
342 rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
343 H_RPTI_TYPE_NESTED |
344 H_RPTI_TYPE_TLB,
345 psize_to_rpti_pgsize(psi),
346 addr, addr + psize);
347 }
348
349 if (rc)
350 pr_err("KVM: TLB page invalidation hcall failed, rc=%ld\n", rc);
351 }
352
kvmppc_radix_flush_pwc(struct kvm * kvm,u64 lpid)353 static void kvmppc_radix_flush_pwc(struct kvm *kvm, u64 lpid)
354 {
355 long rc;
356
357 if (!kvmhv_on_pseries()) {
358 radix__flush_pwc_lpid(lpid);
359 return;
360 }
361
362 if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE))
363 rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(1, 0, 1),
364 lpid, TLBIEL_INVAL_SET_LPID);
365 else
366 rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
367 H_RPTI_TYPE_NESTED |
368 H_RPTI_TYPE_PWC, H_RPTI_PAGE_ALL,
369 0, -1UL);
370 if (rc)
371 pr_err("KVM: TLB PWC invalidation hcall failed, rc=%ld\n", rc);
372 }
373
kvmppc_radix_update_pte(struct kvm * kvm,pte_t * ptep,unsigned long clr,unsigned long set,unsigned long addr,unsigned int shift)374 static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep,
375 unsigned long clr, unsigned long set,
376 unsigned long addr, unsigned int shift)
377 {
378 return __radix_pte_update(ptep, clr, set);
379 }
380
kvmppc_radix_set_pte_at(struct kvm * kvm,unsigned long addr,pte_t * ptep,pte_t pte)381 static void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr,
382 pte_t *ptep, pte_t pte)
383 {
384 radix__set_pte_at(kvm->mm, addr, ptep, pte, 0);
385 }
386
387 static struct kmem_cache *kvm_pte_cache;
388 static struct kmem_cache *kvm_pmd_cache;
389
kvmppc_pte_alloc(void)390 static pte_t *kvmppc_pte_alloc(void)
391 {
392 pte_t *pte;
393
394 pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL);
395 /* pmd_populate() will only reference _pa(pte). */
396 kmemleak_ignore(pte);
397
398 return pte;
399 }
400
kvmppc_pte_free(pte_t * ptep)401 static void kvmppc_pte_free(pte_t *ptep)
402 {
403 kmem_cache_free(kvm_pte_cache, ptep);
404 }
405
kvmppc_pmd_alloc(void)406 static pmd_t *kvmppc_pmd_alloc(void)
407 {
408 pmd_t *pmd;
409
410 pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL);
411 /* pud_populate() will only reference _pa(pmd). */
412 kmemleak_ignore(pmd);
413
414 return pmd;
415 }
416
kvmppc_pmd_free(pmd_t * pmdp)417 static void kvmppc_pmd_free(pmd_t *pmdp)
418 {
419 kmem_cache_free(kvm_pmd_cache, pmdp);
420 }
421
422 /* 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,u64 lpid)423 void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, unsigned long gpa,
424 unsigned int shift,
425 const struct kvm_memory_slot *memslot,
426 u64 lpid)
427
428 {
429 unsigned long old;
430 unsigned long gfn = gpa >> PAGE_SHIFT;
431 unsigned long page_size = PAGE_SIZE;
432 unsigned long hpa;
433
434 old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift);
435 kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
436
437 /* The following only applies to L1 entries */
438 if (lpid != kvm->arch.lpid)
439 return;
440
441 if (!memslot) {
442 memslot = gfn_to_memslot(kvm, gfn);
443 if (!memslot)
444 return;
445 }
446 if (shift) { /* 1GB or 2MB page */
447 page_size = 1ul << shift;
448 if (shift == PMD_SHIFT)
449 kvm->stat.num_2M_pages--;
450 else if (shift == PUD_SHIFT)
451 kvm->stat.num_1G_pages--;
452 }
453
454 gpa &= ~(page_size - 1);
455 hpa = old & PTE_RPN_MASK;
456 kvmhv_remove_nest_rmap_range(kvm, memslot, gpa, hpa, page_size);
457
458 if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap)
459 kvmppc_update_dirty_map(memslot, gfn, page_size);
460 }
461
462 /*
463 * kvmppc_free_p?d are used to free existing page tables, and recursively
464 * descend and clear and free children.
465 * Callers are responsible for flushing the PWC.
466 *
467 * When page tables are being unmapped/freed as part of page fault path
468 * (full == false), valid ptes are generally not expected; however, there
469 * is one situation where they arise, which is when dirty page logging is
470 * turned off for a memslot while the VM is running. The new memslot
471 * becomes visible to page faults before the memslot commit function
472 * gets to flush the memslot, which can lead to a 2MB page mapping being
473 * installed for a guest physical address where there are already 64kB
474 * (or 4kB) mappings (of sub-pages of the same 2MB page).
475 */
kvmppc_unmap_free_pte(struct kvm * kvm,pte_t * pte,bool full,u64 lpid)476 static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full,
477 u64 lpid)
478 {
479 if (full) {
480 memset(pte, 0, sizeof(long) << RADIX_PTE_INDEX_SIZE);
481 } else {
482 pte_t *p = pte;
483 unsigned long it;
484
485 for (it = 0; it < PTRS_PER_PTE; ++it, ++p) {
486 if (pte_val(*p) == 0)
487 continue;
488 kvmppc_unmap_pte(kvm, p,
489 pte_pfn(*p) << PAGE_SHIFT,
490 PAGE_SHIFT, NULL, lpid);
491 }
492 }
493
494 kvmppc_pte_free(pte);
495 }
496
kvmppc_unmap_free_pmd(struct kvm * kvm,pmd_t * pmd,bool full,u64 lpid)497 static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
498 u64 lpid)
499 {
500 unsigned long im;
501 pmd_t *p = pmd;
502
503 for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
504 if (!pmd_present(*p))
505 continue;
506 if (pmd_leaf(*p)) {
507 if (full) {
508 pmd_clear(p);
509 } else {
510 WARN_ON_ONCE(1);
511 kvmppc_unmap_pte(kvm, (pte_t *)p,
512 pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
513 PMD_SHIFT, NULL, lpid);
514 }
515 } else {
516 pte_t *pte;
517
518 pte = pte_offset_kernel(p, 0);
519 kvmppc_unmap_free_pte(kvm, pte, full, lpid);
520 pmd_clear(p);
521 }
522 }
523 kvmppc_pmd_free(pmd);
524 }
525
kvmppc_unmap_free_pud(struct kvm * kvm,pud_t * pud,u64 lpid)526 static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud,
527 u64 lpid)
528 {
529 unsigned long iu;
530 pud_t *p = pud;
531
532 for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) {
533 if (!pud_present(*p))
534 continue;
535 if (pud_leaf(*p)) {
536 pud_clear(p);
537 } else {
538 pmd_t *pmd;
539
540 pmd = pmd_offset(p, 0);
541 kvmppc_unmap_free_pmd(kvm, pmd, true, lpid);
542 pud_clear(p);
543 }
544 }
545 pud_free(kvm->mm, pud);
546 }
547
kvmppc_free_pgtable_radix(struct kvm * kvm,pgd_t * pgd,u64 lpid)548 void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, u64 lpid)
549 {
550 unsigned long ig;
551
552 for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
553 p4d_t *p4d = p4d_offset(pgd, 0);
554 pud_t *pud;
555
556 if (!p4d_present(*p4d))
557 continue;
558 pud = pud_offset(p4d, 0);
559 kvmppc_unmap_free_pud(kvm, pud, lpid);
560 p4d_clear(p4d);
561 }
562 }
563
kvmppc_free_radix(struct kvm * kvm)564 void kvmppc_free_radix(struct kvm *kvm)
565 {
566 if (kvm->arch.pgtable) {
567 kvmppc_free_pgtable_radix(kvm, kvm->arch.pgtable,
568 kvm->arch.lpid);
569 pgd_free(kvm->mm, kvm->arch.pgtable);
570 kvm->arch.pgtable = NULL;
571 }
572 }
573
kvmppc_unmap_free_pmd_entry_table(struct kvm * kvm,pmd_t * pmd,unsigned long gpa,u64 lpid)574 static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd,
575 unsigned long gpa, u64 lpid)
576 {
577 pte_t *pte = pte_offset_kernel(pmd, 0);
578
579 /*
580 * Clearing the pmd entry then flushing the PWC ensures that the pte
581 * page no longer be cached by the MMU, so can be freed without
582 * flushing the PWC again.
583 */
584 pmd_clear(pmd);
585 kvmppc_radix_flush_pwc(kvm, lpid);
586
587 kvmppc_unmap_free_pte(kvm, pte, false, lpid);
588 }
589
kvmppc_unmap_free_pud_entry_table(struct kvm * kvm,pud_t * pud,unsigned long gpa,u64 lpid)590 static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
591 unsigned long gpa, u64 lpid)
592 {
593 pmd_t *pmd = pmd_offset(pud, 0);
594
595 /*
596 * Clearing the pud entry then flushing the PWC ensures that the pmd
597 * page and any children pte pages will no longer be cached by the MMU,
598 * so can be freed without flushing the PWC again.
599 */
600 pud_clear(pud);
601 kvmppc_radix_flush_pwc(kvm, lpid);
602
603 kvmppc_unmap_free_pmd(kvm, pmd, false, lpid);
604 }
605
606 /*
607 * There are a number of bits which may differ between different faults to
608 * the same partition scope entry. RC bits, in the course of cleaning and
609 * aging. And the write bit can change, either the access could have been
610 * upgraded, or a read fault could happen concurrently with a write fault
611 * that sets those bits first.
612 */
613 #define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED))
614
kvmppc_create_pte(struct kvm * kvm,pgd_t * pgtable,pte_t pte,unsigned long gpa,unsigned int level,unsigned long mmu_seq,u64 lpid,unsigned long * rmapp,struct rmap_nested ** n_rmap)615 int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
616 unsigned long gpa, unsigned int level,
617 unsigned long mmu_seq, u64 lpid,
618 unsigned long *rmapp, struct rmap_nested **n_rmap)
619 {
620 pgd_t *pgd;
621 p4d_t *p4d;
622 pud_t *pud, *new_pud = NULL;
623 pmd_t *pmd, *new_pmd = NULL;
624 pte_t *ptep, *new_ptep = NULL;
625 int ret;
626
627 /* Traverse the guest's 2nd-level tree, allocate new levels needed */
628 pgd = pgtable + pgd_index(gpa);
629 p4d = p4d_offset(pgd, gpa);
630
631 pud = NULL;
632 if (p4d_present(*p4d))
633 pud = pud_offset(p4d, gpa);
634 else
635 new_pud = pud_alloc_one(kvm->mm, gpa);
636
637 pmd = NULL;
638 if (pud && pud_present(*pud) && !pud_leaf(*pud))
639 pmd = pmd_offset(pud, gpa);
640 else if (level <= 1)
641 new_pmd = kvmppc_pmd_alloc();
642
643 if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_leaf(*pmd)))
644 new_ptep = kvmppc_pte_alloc();
645
646 /* Check if we might have been invalidated; let the guest retry if so */
647 spin_lock(&kvm->mmu_lock);
648 ret = -EAGAIN;
649 if (mmu_invalidate_retry(kvm, mmu_seq))
650 goto out_unlock;
651
652 /* Now traverse again under the lock and change the tree */
653 ret = -ENOMEM;
654 if (p4d_none(*p4d)) {
655 if (!new_pud)
656 goto out_unlock;
657 p4d_populate(kvm->mm, p4d, new_pud);
658 new_pud = NULL;
659 }
660 pud = pud_offset(p4d, gpa);
661 if (pud_leaf(*pud)) {
662 unsigned long hgpa = gpa & PUD_MASK;
663
664 /* Check if we raced and someone else has set the same thing */
665 if (level == 2) {
666 if (pud_raw(*pud) == pte_raw(pte)) {
667 ret = 0;
668 goto out_unlock;
669 }
670 /* Valid 1GB page here already, add our extra bits */
671 WARN_ON_ONCE((pud_val(*pud) ^ pte_val(pte)) &
672 PTE_BITS_MUST_MATCH);
673 kvmppc_radix_update_pte(kvm, (pte_t *)pud,
674 0, pte_val(pte), hgpa, PUD_SHIFT);
675 ret = 0;
676 goto out_unlock;
677 }
678 /*
679 * If we raced with another CPU which has just put
680 * a 1GB pte in after we saw a pmd page, try again.
681 */
682 if (!new_pmd) {
683 ret = -EAGAIN;
684 goto out_unlock;
685 }
686 /* Valid 1GB page here already, remove it */
687 kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL,
688 lpid);
689 }
690 if (level == 2) {
691 if (!pud_none(*pud)) {
692 /*
693 * There's a page table page here, but we wanted to
694 * install a large page, so remove and free the page
695 * table page.
696 */
697 kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa, lpid);
698 }
699 kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte);
700 if (rmapp && n_rmap)
701 kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
702 ret = 0;
703 goto out_unlock;
704 }
705 if (pud_none(*pud)) {
706 if (!new_pmd)
707 goto out_unlock;
708 pud_populate(kvm->mm, pud, new_pmd);
709 new_pmd = NULL;
710 }
711 pmd = pmd_offset(pud, gpa);
712 if (pmd_leaf(*pmd)) {
713 unsigned long lgpa = gpa & PMD_MASK;
714
715 /* Check if we raced and someone else has set the same thing */
716 if (level == 1) {
717 if (pmd_raw(*pmd) == pte_raw(pte)) {
718 ret = 0;
719 goto out_unlock;
720 }
721 /* Valid 2MB page here already, add our extra bits */
722 WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) &
723 PTE_BITS_MUST_MATCH);
724 kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd),
725 0, pte_val(pte), lgpa, PMD_SHIFT);
726 ret = 0;
727 goto out_unlock;
728 }
729
730 /*
731 * If we raced with another CPU which has just put
732 * a 2MB pte in after we saw a pte page, try again.
733 */
734 if (!new_ptep) {
735 ret = -EAGAIN;
736 goto out_unlock;
737 }
738 /* Valid 2MB page here already, remove it */
739 kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL,
740 lpid);
741 }
742 if (level == 1) {
743 if (!pmd_none(*pmd)) {
744 /*
745 * There's a page table page here, but we wanted to
746 * install a large page, so remove and free the page
747 * table page.
748 */
749 kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa, lpid);
750 }
751 kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
752 if (rmapp && n_rmap)
753 kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
754 ret = 0;
755 goto out_unlock;
756 }
757 if (pmd_none(*pmd)) {
758 if (!new_ptep)
759 goto out_unlock;
760 pmd_populate(kvm->mm, pmd, new_ptep);
761 new_ptep = NULL;
762 }
763 ptep = pte_offset_kernel(pmd, gpa);
764 if (pte_present(*ptep)) {
765 /* Check if someone else set the same thing */
766 if (pte_raw(*ptep) == pte_raw(pte)) {
767 ret = 0;
768 goto out_unlock;
769 }
770 /* Valid page here already, add our extra bits */
771 WARN_ON_ONCE((pte_val(*ptep) ^ pte_val(pte)) &
772 PTE_BITS_MUST_MATCH);
773 kvmppc_radix_update_pte(kvm, ptep, 0, pte_val(pte), gpa, 0);
774 ret = 0;
775 goto out_unlock;
776 }
777 kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte);
778 if (rmapp && n_rmap)
779 kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
780 ret = 0;
781
782 out_unlock:
783 spin_unlock(&kvm->mmu_lock);
784 if (new_pud)
785 pud_free(kvm->mm, new_pud);
786 if (new_pmd)
787 kvmppc_pmd_free(new_pmd);
788 if (new_ptep)
789 kvmppc_pte_free(new_ptep);
790 return ret;
791 }
792
kvmppc_hv_handle_set_rc(struct kvm * kvm,bool nested,bool writing,unsigned long gpa,u64 lpid)793 bool kvmppc_hv_handle_set_rc(struct kvm *kvm, bool nested, bool writing,
794 unsigned long gpa, u64 lpid)
795 {
796 unsigned long pgflags;
797 unsigned int shift;
798 pte_t *ptep;
799
800 /*
801 * Need to set an R or C bit in the 2nd-level tables;
802 * since we are just helping out the hardware here,
803 * it is sufficient to do what the hardware does.
804 */
805 pgflags = _PAGE_ACCESSED;
806 if (writing)
807 pgflags |= _PAGE_DIRTY;
808
809 if (nested)
810 ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
811 else
812 ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
813
814 if (ptep && pte_present(*ptep) && (!writing || pte_write(*ptep))) {
815 kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, gpa, shift);
816 return true;
817 }
818 return false;
819 }
820
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)821 int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
822 unsigned long gpa,
823 struct kvm_memory_slot *memslot,
824 bool writing, bool kvm_ro,
825 pte_t *inserted_pte, unsigned int *levelp)
826 {
827 struct kvm *kvm = vcpu->kvm;
828 struct page *page = NULL;
829 unsigned long mmu_seq;
830 unsigned long hva, gfn = gpa >> PAGE_SHIFT;
831 bool upgrade_write = false;
832 bool *upgrade_p = &upgrade_write;
833 pte_t pte, *ptep;
834 unsigned int shift, level;
835 int ret;
836 bool large_enable;
837
838 /* used to check for invalidations in progress */
839 mmu_seq = kvm->mmu_invalidate_seq;
840 smp_rmb();
841
842 /*
843 * Do a fast check first, since __gfn_to_pfn_memslot doesn't
844 * do it with !atomic && !async, which is how we call it.
845 * We always ask for write permission since the common case
846 * is that the page is writable.
847 */
848 hva = gfn_to_hva_memslot(memslot, gfn);
849 if (!kvm_ro && get_user_page_fast_only(hva, FOLL_WRITE, &page)) {
850 upgrade_write = true;
851 } else {
852 unsigned long pfn;
853
854 /* Call KVM generic code to do the slow-path check */
855 pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL,
856 writing, upgrade_p, NULL);
857 if (is_error_noslot_pfn(pfn))
858 return -EFAULT;
859 page = NULL;
860 if (pfn_valid(pfn)) {
861 page = pfn_to_page(pfn);
862 if (PageReserved(page))
863 page = NULL;
864 }
865 }
866
867 /*
868 * Read the PTE from the process' radix tree and use that
869 * so we get the shift and attribute bits.
870 */
871 spin_lock(&kvm->mmu_lock);
872 ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &shift);
873 pte = __pte(0);
874 if (ptep)
875 pte = READ_ONCE(*ptep);
876 spin_unlock(&kvm->mmu_lock);
877 /*
878 * If the PTE disappeared temporarily due to a THP
879 * collapse, just return and let the guest try again.
880 */
881 if (!pte_present(pte)) {
882 if (page)
883 put_page(page);
884 return RESUME_GUEST;
885 }
886
887 /* If we're logging dirty pages, always map single pages */
888 large_enable = !(memslot->flags & KVM_MEM_LOG_DIRTY_PAGES);
889
890 /* Get pte level from shift/size */
891 if (large_enable && shift == PUD_SHIFT &&
892 (gpa & (PUD_SIZE - PAGE_SIZE)) ==
893 (hva & (PUD_SIZE - PAGE_SIZE))) {
894 level = 2;
895 } else if (large_enable && shift == PMD_SHIFT &&
896 (gpa & (PMD_SIZE - PAGE_SIZE)) ==
897 (hva & (PMD_SIZE - PAGE_SIZE))) {
898 level = 1;
899 } else {
900 level = 0;
901 if (shift > PAGE_SHIFT) {
902 /*
903 * If the pte maps more than one page, bring over
904 * bits from the virtual address to get the real
905 * address of the specific single page we want.
906 */
907 unsigned long rpnmask = (1ul << shift) - PAGE_SIZE;
908 pte = __pte(pte_val(pte) | (hva & rpnmask));
909 }
910 }
911
912 pte = __pte(pte_val(pte) | _PAGE_EXEC | _PAGE_ACCESSED);
913 if (writing || upgrade_write) {
914 if (pte_val(pte) & _PAGE_WRITE)
915 pte = __pte(pte_val(pte) | _PAGE_DIRTY);
916 } else {
917 pte = __pte(pte_val(pte) & ~(_PAGE_WRITE | _PAGE_DIRTY));
918 }
919
920 /* Allocate space in the tree and write the PTE */
921 ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level,
922 mmu_seq, kvm->arch.lpid, NULL, NULL);
923 if (inserted_pte)
924 *inserted_pte = pte;
925 if (levelp)
926 *levelp = level;
927
928 if (page) {
929 if (!ret && (pte_val(pte) & _PAGE_WRITE))
930 set_page_dirty_lock(page);
931 put_page(page);
932 }
933
934 /* Increment number of large pages if we (successfully) inserted one */
935 if (!ret) {
936 if (level == 1)
937 kvm->stat.num_2M_pages++;
938 else if (level == 2)
939 kvm->stat.num_1G_pages++;
940 }
941
942 return ret;
943 }
944
kvmppc_book3s_radix_page_fault(struct kvm_vcpu * vcpu,unsigned long ea,unsigned long dsisr)945 int kvmppc_book3s_radix_page_fault(struct kvm_vcpu *vcpu,
946 unsigned long ea, unsigned long dsisr)
947 {
948 struct kvm *kvm = vcpu->kvm;
949 unsigned long gpa, gfn;
950 struct kvm_memory_slot *memslot;
951 long ret;
952 bool writing = !!(dsisr & DSISR_ISSTORE);
953 bool kvm_ro = false;
954
955 /* Check for unusual errors */
956 if (dsisr & DSISR_UNSUPP_MMU) {
957 pr_err("KVM: Got unsupported MMU fault\n");
958 return -EFAULT;
959 }
960 if (dsisr & DSISR_BADACCESS) {
961 /* Reflect to the guest as DSI */
962 pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
963 kvmppc_core_queue_data_storage(vcpu,
964 kvmppc_get_msr(vcpu) & SRR1_PREFIXED,
965 ea, dsisr);
966 return RESUME_GUEST;
967 }
968
969 /* Translate the logical address */
970 gpa = vcpu->arch.fault_gpa & ~0xfffUL;
971 gpa &= ~0xF000000000000000ul;
972 gfn = gpa >> PAGE_SHIFT;
973 if (!(dsisr & DSISR_PRTABLE_FAULT))
974 gpa |= ea & 0xfff;
975
976 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
977 return kvmppc_send_page_to_uv(kvm, gfn);
978
979 /* Get the corresponding memslot */
980 memslot = gfn_to_memslot(kvm, gfn);
981
982 /* No memslot means it's an emulated MMIO region */
983 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
984 if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
985 DSISR_SET_RC)) {
986 /*
987 * Bad address in guest page table tree, or other
988 * unusual error - reflect it to the guest as DSI.
989 */
990 kvmppc_core_queue_data_storage(vcpu,
991 kvmppc_get_msr(vcpu) & SRR1_PREFIXED,
992 ea, dsisr);
993 return RESUME_GUEST;
994 }
995 return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
996 }
997
998 if (memslot->flags & KVM_MEM_READONLY) {
999 if (writing) {
1000 /* give the guest a DSI */
1001 kvmppc_core_queue_data_storage(vcpu,
1002 kvmppc_get_msr(vcpu) & SRR1_PREFIXED,
1003 ea, DSISR_ISSTORE | DSISR_PROTFAULT);
1004 return RESUME_GUEST;
1005 }
1006 kvm_ro = true;
1007 }
1008
1009 /* Failed to set the reference/change bits */
1010 if (dsisr & DSISR_SET_RC) {
1011 spin_lock(&kvm->mmu_lock);
1012 if (kvmppc_hv_handle_set_rc(kvm, false, writing,
1013 gpa, kvm->arch.lpid))
1014 dsisr &= ~DSISR_SET_RC;
1015 spin_unlock(&kvm->mmu_lock);
1016
1017 if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
1018 DSISR_PROTFAULT | DSISR_SET_RC)))
1019 return RESUME_GUEST;
1020 }
1021
1022 /* Try to insert a pte */
1023 ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, writing,
1024 kvm_ro, NULL, NULL);
1025
1026 if (ret == 0 || ret == -EAGAIN)
1027 ret = RESUME_GUEST;
1028 return ret;
1029 }
1030
1031 /* Called with kvm->mmu_lock held */
kvm_unmap_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)1032 void kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1033 unsigned long gfn)
1034 {
1035 pte_t *ptep;
1036 unsigned long gpa = gfn << PAGE_SHIFT;
1037 unsigned int shift;
1038
1039 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) {
1040 uv_page_inval(kvm->arch.lpid, gpa, PAGE_SHIFT);
1041 return;
1042 }
1043
1044 ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1045 if (ptep && pte_present(*ptep))
1046 kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
1047 kvm->arch.lpid);
1048 }
1049
1050 /* Called with kvm->mmu_lock held */
kvm_age_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)1051 bool kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1052 unsigned long gfn)
1053 {
1054 pte_t *ptep;
1055 unsigned long gpa = gfn << PAGE_SHIFT;
1056 unsigned int shift;
1057 bool ref = false;
1058 unsigned long old, *rmapp;
1059
1060 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1061 return ref;
1062
1063 ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1064 if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
1065 old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
1066 gpa, shift);
1067 /* XXX need to flush tlb here? */
1068 /* Also clear bit in ptes in shadow pgtable for nested guests */
1069 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1070 kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_ACCESSED, 0,
1071 old & PTE_RPN_MASK,
1072 1UL << shift);
1073 ref = true;
1074 }
1075 return ref;
1076 }
1077
1078 /* Called with kvm->mmu_lock held */
kvm_test_age_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)1079 bool kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1080 unsigned long gfn)
1081
1082 {
1083 pte_t *ptep;
1084 unsigned long gpa = gfn << PAGE_SHIFT;
1085 unsigned int shift;
1086 bool ref = false;
1087
1088 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1089 return ref;
1090
1091 ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1092 if (ptep && pte_present(*ptep) && pte_young(*ptep))
1093 ref = true;
1094 return ref;
1095 }
1096
1097 /* 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)1098 static int kvm_radix_test_clear_dirty(struct kvm *kvm,
1099 struct kvm_memory_slot *memslot, int pagenum)
1100 {
1101 unsigned long gfn = memslot->base_gfn + pagenum;
1102 unsigned long gpa = gfn << PAGE_SHIFT;
1103 pte_t *ptep, pte;
1104 unsigned int shift;
1105 int ret = 0;
1106 unsigned long old, *rmapp;
1107
1108 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1109 return ret;
1110
1111 /*
1112 * For performance reasons we don't hold kvm->mmu_lock while walking the
1113 * partition scoped table.
1114 */
1115 ptep = find_kvm_secondary_pte_unlocked(kvm, gpa, &shift);
1116 if (!ptep)
1117 return 0;
1118
1119 pte = READ_ONCE(*ptep);
1120 if (pte_present(pte) && pte_dirty(pte)) {
1121 spin_lock(&kvm->mmu_lock);
1122 /*
1123 * Recheck the pte again
1124 */
1125 if (pte_val(pte) != pte_val(*ptep)) {
1126 /*
1127 * We have KVM_MEM_LOG_DIRTY_PAGES enabled. Hence we can
1128 * only find PAGE_SIZE pte entries here. We can continue
1129 * to use the pte addr returned by above page table
1130 * walk.
1131 */
1132 if (!pte_present(*ptep) || !pte_dirty(*ptep)) {
1133 spin_unlock(&kvm->mmu_lock);
1134 return 0;
1135 }
1136 }
1137
1138 ret = 1;
1139 VM_BUG_ON(shift);
1140 old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,
1141 gpa, shift);
1142 kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid);
1143 /* Also clear bit in ptes in shadow pgtable for nested guests */
1144 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1145 kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_DIRTY, 0,
1146 old & PTE_RPN_MASK,
1147 1UL << shift);
1148 spin_unlock(&kvm->mmu_lock);
1149 }
1150 return ret;
1151 }
1152
kvmppc_hv_get_dirty_log_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long * map)1153 long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm,
1154 struct kvm_memory_slot *memslot, unsigned long *map)
1155 {
1156 unsigned long i, j;
1157 int npages;
1158
1159 for (i = 0; i < memslot->npages; i = j) {
1160 npages = kvm_radix_test_clear_dirty(kvm, memslot, i);
1161
1162 /*
1163 * Note that if npages > 0 then i must be a multiple of npages,
1164 * since huge pages are only used to back the guest at guest
1165 * real addresses that are a multiple of their size.
1166 * Since we have at most one PTE covering any given guest
1167 * real address, if npages > 1 we can skip to i + npages.
1168 */
1169 j = i + 1;
1170 if (npages) {
1171 set_dirty_bits(map, i, npages);
1172 j = i + npages;
1173 }
1174 }
1175 return 0;
1176 }
1177
kvmppc_radix_flush_memslot(struct kvm * kvm,const struct kvm_memory_slot * memslot)1178 void kvmppc_radix_flush_memslot(struct kvm *kvm,
1179 const struct kvm_memory_slot *memslot)
1180 {
1181 unsigned long n;
1182 pte_t *ptep;
1183 unsigned long gpa;
1184 unsigned int shift;
1185
1186 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)
1187 kvmppc_uvmem_drop_pages(memslot, kvm, true);
1188
1189 if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1190 return;
1191
1192 gpa = memslot->base_gfn << PAGE_SHIFT;
1193 spin_lock(&kvm->mmu_lock);
1194 for (n = memslot->npages; n; --n) {
1195 ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1196 if (ptep && pte_present(*ptep))
1197 kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
1198 kvm->arch.lpid);
1199 gpa += PAGE_SIZE;
1200 }
1201 /*
1202 * Increase the mmu notifier sequence number to prevent any page
1203 * fault that read the memslot earlier from writing a PTE.
1204 */
1205 kvm->mmu_invalidate_seq++;
1206 spin_unlock(&kvm->mmu_lock);
1207 }
1208
add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info * info,int psize,int * indexp)1209 static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info,
1210 int psize, int *indexp)
1211 {
1212 if (!mmu_psize_defs[psize].shift)
1213 return;
1214 info->ap_encodings[*indexp] = mmu_psize_defs[psize].shift |
1215 (mmu_psize_defs[psize].ap << 29);
1216 ++(*indexp);
1217 }
1218
kvmhv_get_rmmu_info(struct kvm * kvm,struct kvm_ppc_rmmu_info * info)1219 int kvmhv_get_rmmu_info(struct kvm *kvm, struct kvm_ppc_rmmu_info *info)
1220 {
1221 int i;
1222
1223 if (!radix_enabled())
1224 return -EINVAL;
1225 memset(info, 0, sizeof(*info));
1226
1227 /* 4k page size */
1228 info->geometries[0].page_shift = 12;
1229 info->geometries[0].level_bits[0] = 9;
1230 for (i = 1; i < 4; ++i)
1231 info->geometries[0].level_bits[i] = p9_supported_radix_bits[i];
1232 /* 64k page size */
1233 info->geometries[1].page_shift = 16;
1234 for (i = 0; i < 4; ++i)
1235 info->geometries[1].level_bits[i] = p9_supported_radix_bits[i];
1236
1237 i = 0;
1238 add_rmmu_ap_encoding(info, MMU_PAGE_4K, &i);
1239 add_rmmu_ap_encoding(info, MMU_PAGE_64K, &i);
1240 add_rmmu_ap_encoding(info, MMU_PAGE_2M, &i);
1241 add_rmmu_ap_encoding(info, MMU_PAGE_1G, &i);
1242
1243 return 0;
1244 }
1245
kvmppc_init_vm_radix(struct kvm * kvm)1246 int kvmppc_init_vm_radix(struct kvm *kvm)
1247 {
1248 kvm->arch.pgtable = pgd_alloc(kvm->mm);
1249 if (!kvm->arch.pgtable)
1250 return -ENOMEM;
1251 return 0;
1252 }
1253
pte_ctor(void * addr)1254 static void pte_ctor(void *addr)
1255 {
1256 memset(addr, 0, RADIX_PTE_TABLE_SIZE);
1257 }
1258
pmd_ctor(void * addr)1259 static void pmd_ctor(void *addr)
1260 {
1261 memset(addr, 0, RADIX_PMD_TABLE_SIZE);
1262 }
1263
1264 struct debugfs_radix_state {
1265 struct kvm *kvm;
1266 struct mutex mutex;
1267 unsigned long gpa;
1268 int lpid;
1269 int chars_left;
1270 int buf_index;
1271 char buf[128];
1272 u8 hdr;
1273 };
1274
debugfs_radix_open(struct inode * inode,struct file * file)1275 static int debugfs_radix_open(struct inode *inode, struct file *file)
1276 {
1277 struct kvm *kvm = inode->i_private;
1278 struct debugfs_radix_state *p;
1279
1280 p = kzalloc(sizeof(*p), GFP_KERNEL);
1281 if (!p)
1282 return -ENOMEM;
1283
1284 kvm_get_kvm(kvm);
1285 p->kvm = kvm;
1286 mutex_init(&p->mutex);
1287 file->private_data = p;
1288
1289 return nonseekable_open(inode, file);
1290 }
1291
debugfs_radix_release(struct inode * inode,struct file * file)1292 static int debugfs_radix_release(struct inode *inode, struct file *file)
1293 {
1294 struct debugfs_radix_state *p = file->private_data;
1295
1296 kvm_put_kvm(p->kvm);
1297 kfree(p);
1298 return 0;
1299 }
1300
debugfs_radix_read(struct file * file,char __user * buf,size_t len,loff_t * ppos)1301 static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
1302 size_t len, loff_t *ppos)
1303 {
1304 struct debugfs_radix_state *p = file->private_data;
1305 ssize_t ret, r;
1306 unsigned long n;
1307 struct kvm *kvm;
1308 unsigned long gpa;
1309 pgd_t *pgt;
1310 struct kvm_nested_guest *nested;
1311 pgd_t *pgdp;
1312 p4d_t p4d, *p4dp;
1313 pud_t pud, *pudp;
1314 pmd_t pmd, *pmdp;
1315 pte_t *ptep;
1316 int shift;
1317 unsigned long pte;
1318
1319 kvm = p->kvm;
1320 if (!kvm_is_radix(kvm))
1321 return 0;
1322
1323 ret = mutex_lock_interruptible(&p->mutex);
1324 if (ret)
1325 return ret;
1326
1327 if (p->chars_left) {
1328 n = p->chars_left;
1329 if (n > len)
1330 n = len;
1331 r = copy_to_user(buf, p->buf + p->buf_index, n);
1332 n -= r;
1333 p->chars_left -= n;
1334 p->buf_index += n;
1335 buf += n;
1336 len -= n;
1337 ret = n;
1338 if (r) {
1339 if (!n)
1340 ret = -EFAULT;
1341 goto out;
1342 }
1343 }
1344
1345 gpa = p->gpa;
1346 nested = NULL;
1347 pgt = NULL;
1348 while (len != 0 && p->lpid >= 0) {
1349 if (gpa >= RADIX_PGTABLE_RANGE) {
1350 gpa = 0;
1351 pgt = NULL;
1352 if (nested) {
1353 kvmhv_put_nested(nested);
1354 nested = NULL;
1355 }
1356 p->lpid = kvmhv_nested_next_lpid(kvm, p->lpid);
1357 p->hdr = 0;
1358 if (p->lpid < 0)
1359 break;
1360 }
1361 if (!pgt) {
1362 if (p->lpid == 0) {
1363 pgt = kvm->arch.pgtable;
1364 } else {
1365 nested = kvmhv_get_nested(kvm, p->lpid, false);
1366 if (!nested) {
1367 gpa = RADIX_PGTABLE_RANGE;
1368 continue;
1369 }
1370 pgt = nested->shadow_pgtable;
1371 }
1372 }
1373 n = 0;
1374 if (!p->hdr) {
1375 if (p->lpid > 0)
1376 n = scnprintf(p->buf, sizeof(p->buf),
1377 "\nNested LPID %d: ", p->lpid);
1378 n += scnprintf(p->buf + n, sizeof(p->buf) - n,
1379 "pgdir: %lx\n", (unsigned long)pgt);
1380 p->hdr = 1;
1381 goto copy;
1382 }
1383
1384 pgdp = pgt + pgd_index(gpa);
1385 p4dp = p4d_offset(pgdp, gpa);
1386 p4d = READ_ONCE(*p4dp);
1387 if (!(p4d_val(p4d) & _PAGE_PRESENT)) {
1388 gpa = (gpa & P4D_MASK) + P4D_SIZE;
1389 continue;
1390 }
1391
1392 pudp = pud_offset(&p4d, gpa);
1393 pud = READ_ONCE(*pudp);
1394 if (!(pud_val(pud) & _PAGE_PRESENT)) {
1395 gpa = (gpa & PUD_MASK) + PUD_SIZE;
1396 continue;
1397 }
1398 if (pud_val(pud) & _PAGE_PTE) {
1399 pte = pud_val(pud);
1400 shift = PUD_SHIFT;
1401 goto leaf;
1402 }
1403
1404 pmdp = pmd_offset(&pud, gpa);
1405 pmd = READ_ONCE(*pmdp);
1406 if (!(pmd_val(pmd) & _PAGE_PRESENT)) {
1407 gpa = (gpa & PMD_MASK) + PMD_SIZE;
1408 continue;
1409 }
1410 if (pmd_val(pmd) & _PAGE_PTE) {
1411 pte = pmd_val(pmd);
1412 shift = PMD_SHIFT;
1413 goto leaf;
1414 }
1415
1416 ptep = pte_offset_kernel(&pmd, gpa);
1417 pte = pte_val(READ_ONCE(*ptep));
1418 if (!(pte & _PAGE_PRESENT)) {
1419 gpa += PAGE_SIZE;
1420 continue;
1421 }
1422 shift = PAGE_SHIFT;
1423 leaf:
1424 n = scnprintf(p->buf, sizeof(p->buf),
1425 " %lx: %lx %d\n", gpa, pte, shift);
1426 gpa += 1ul << shift;
1427 copy:
1428 p->chars_left = n;
1429 if (n > len)
1430 n = len;
1431 r = copy_to_user(buf, p->buf, n);
1432 n -= r;
1433 p->chars_left -= n;
1434 p->buf_index = n;
1435 buf += n;
1436 len -= n;
1437 ret += n;
1438 if (r) {
1439 if (!ret)
1440 ret = -EFAULT;
1441 break;
1442 }
1443 }
1444 p->gpa = gpa;
1445 if (nested)
1446 kvmhv_put_nested(nested);
1447
1448 out:
1449 mutex_unlock(&p->mutex);
1450 return ret;
1451 }
1452
debugfs_radix_write(struct file * file,const char __user * buf,size_t len,loff_t * ppos)1453 static ssize_t debugfs_radix_write(struct file *file, const char __user *buf,
1454 size_t len, loff_t *ppos)
1455 {
1456 return -EACCES;
1457 }
1458
1459 static const struct file_operations debugfs_radix_fops = {
1460 .owner = THIS_MODULE,
1461 .open = debugfs_radix_open,
1462 .release = debugfs_radix_release,
1463 .read = debugfs_radix_read,
1464 .write = debugfs_radix_write,
1465 .llseek = generic_file_llseek,
1466 };
1467
kvmhv_radix_debugfs_init(struct kvm * kvm)1468 void kvmhv_radix_debugfs_init(struct kvm *kvm)
1469 {
1470 debugfs_create_file("radix", 0400, kvm->debugfs_dentry, kvm,
1471 &debugfs_radix_fops);
1472 }
1473
kvmppc_radix_init(void)1474 int kvmppc_radix_init(void)
1475 {
1476 unsigned long size = sizeof(void *) << RADIX_PTE_INDEX_SIZE;
1477
1478 kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, 0, pte_ctor);
1479 if (!kvm_pte_cache)
1480 return -ENOMEM;
1481
1482 size = sizeof(void *) << RADIX_PMD_INDEX_SIZE;
1483
1484 kvm_pmd_cache = kmem_cache_create("kvm-pmd", size, size, 0, pmd_ctor);
1485 if (!kvm_pmd_cache) {
1486 kmem_cache_destroy(kvm_pte_cache);
1487 return -ENOMEM;
1488 }
1489
1490 return 0;
1491 }
1492
kvmppc_radix_exit(void)1493 void kvmppc_radix_exit(void)
1494 {
1495 kmem_cache_destroy(kvm_pte_cache);
1496 kmem_cache_destroy(kvm_pmd_cache);
1497 }
1498