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Linux/arch/powerpc/kvm/book3s_64_vio.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  *
  4  * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
  5  * Copyright 2011 David Gibson, IBM Corporation <dwg@au1.ibm.com>
  6  * Copyright 2016 Alexey Kardashevskiy, IBM Corporation <aik@au1.ibm.com>
  7  */
  8 
  9 #include <linux/types.h>
 10 #include <linux/string.h>
 11 #include <linux/kvm.h>
 12 #include <linux/kvm_host.h>
 13 #include <linux/highmem.h>
 14 #include <linux/gfp.h>
 15 #include <linux/slab.h>
 16 #include <linux/sched/signal.h>
 17 #include <linux/hugetlb.h>
 18 #include <linux/list.h>
 19 #include <linux/anon_inodes.h>
 20 #include <linux/iommu.h>
 21 #include <linux/file.h>
 22 #include <linux/mm.h>
 23 #include <linux/rcupdate_wait.h>
 24 
 25 #include <asm/kvm_ppc.h>
 26 #include <asm/kvm_book3s.h>
 27 #include <asm/book3s/64/mmu-hash.h>
 28 #include <asm/hvcall.h>
 29 #include <asm/synch.h>
 30 #include <asm/ppc-opcode.h>
 31 #include <asm/udbg.h>
 32 #include <asm/iommu.h>
 33 #include <asm/tce.h>
 34 #include <asm/mmu_context.h>
 35 
 36 static struct kvmppc_spapr_tce_table *kvmppc_find_table(struct kvm *kvm,
 37         unsigned long liobn)
 38 {
 39         struct kvmppc_spapr_tce_table *stt;
 40 
 41         list_for_each_entry_lockless(stt, &kvm->arch.spapr_tce_tables, list)
 42                 if (stt->liobn == liobn)
 43                         return stt;
 44 
 45         return NULL;
 46 }
 47 
 48 static unsigned long kvmppc_tce_pages(unsigned long iommu_pages)
 49 {
 50         return ALIGN(iommu_pages * sizeof(u64), PAGE_SIZE) / PAGE_SIZE;
 51 }
 52 
 53 static unsigned long kvmppc_stt_pages(unsigned long tce_pages)
 54 {
 55         unsigned long stt_bytes = sizeof(struct kvmppc_spapr_tce_table) +
 56                         (tce_pages * sizeof(struct page *));
 57 
 58         return tce_pages + ALIGN(stt_bytes, PAGE_SIZE) / PAGE_SIZE;
 59 }
 60 
 61 static void kvm_spapr_tce_iommu_table_free(struct rcu_head *head)
 62 {
 63         struct kvmppc_spapr_tce_iommu_table *stit = container_of(head,
 64                         struct kvmppc_spapr_tce_iommu_table, rcu);
 65 
 66         iommu_tce_table_put(stit->tbl);
 67 
 68         kfree(stit);
 69 }
 70 
 71 static void kvm_spapr_tce_liobn_put(struct kref *kref)
 72 {
 73         struct kvmppc_spapr_tce_iommu_table *stit = container_of(kref,
 74                         struct kvmppc_spapr_tce_iommu_table, kref);
 75 
 76         list_del_rcu(&stit->next);
 77 
 78         call_rcu(&stit->rcu, kvm_spapr_tce_iommu_table_free);
 79 }
 80 
 81 void kvm_spapr_tce_release_iommu_group(struct kvm *kvm,
 82                                        struct iommu_group *grp)
 83 {
 84         int i;
 85         struct kvmppc_spapr_tce_table *stt;
 86         struct kvmppc_spapr_tce_iommu_table *stit, *tmp;
 87         struct iommu_table_group *table_group = NULL;
 88 
 89         rcu_read_lock();
 90         list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) {
 91 
 92                 table_group = iommu_group_get_iommudata(grp);
 93                 if (WARN_ON(!table_group))
 94                         continue;
 95 
 96                 list_for_each_entry_safe(stit, tmp, &stt->iommu_tables, next) {
 97                         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 98                                 if (table_group->tables[i] != stit->tbl)
 99                                         continue;
100 
101                                 kref_put(&stit->kref, kvm_spapr_tce_liobn_put);
102                         }
103                 }
104                 cond_resched_rcu();
105         }
106         rcu_read_unlock();
107 }
108 
109 long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
110                                       struct iommu_group *grp)
111 {
112         struct kvmppc_spapr_tce_table *stt = NULL;
113         bool found = false;
114         struct iommu_table *tbl = NULL;
115         struct iommu_table_group *table_group;
116         long i;
117         struct kvmppc_spapr_tce_iommu_table *stit;
118         struct fd f;
119 
120         f = fdget(tablefd);
121         if (!f.file)
122                 return -EBADF;
123 
124         rcu_read_lock();
125         list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) {
126                 if (stt == f.file->private_data) {
127                         found = true;
128                         break;
129                 }
130         }
131         rcu_read_unlock();
132 
133         if (!found) {
134                 fdput(f);
135                 return -EINVAL;
136         }
137 
138         table_group = iommu_group_get_iommudata(grp);
139         if (WARN_ON(!table_group)) {
140                 fdput(f);
141                 return -EFAULT;
142         }
143 
144         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
145                 struct iommu_table *tbltmp = table_group->tables[i];
146 
147                 if (!tbltmp)
148                         continue;
149                 /* Make sure hardware table parameters are compatible */
150                 if ((tbltmp->it_page_shift <= stt->page_shift) &&
151                                 (tbltmp->it_offset << tbltmp->it_page_shift ==
152                                  stt->offset << stt->page_shift) &&
153                                 (tbltmp->it_size << tbltmp->it_page_shift >=
154                                  stt->size << stt->page_shift)) {
155                         /*
156                          * Reference the table to avoid races with
157                          * add/remove DMA windows.
158                          */
159                         tbl = iommu_tce_table_get(tbltmp);
160                         break;
161                 }
162         }
163         if (!tbl) {
164                 fdput(f);
165                 return -EINVAL;
166         }
167 
168         rcu_read_lock();
169         list_for_each_entry_rcu(stit, &stt->iommu_tables, next) {
170                 if (tbl != stit->tbl)
171                         continue;
172 
173                 if (!kref_get_unless_zero(&stit->kref)) {
174                         /* stit is being destroyed */
175                         iommu_tce_table_put(tbl);
176                         rcu_read_unlock();
177                         fdput(f);
178                         return -ENOTTY;
179                 }
180                 /*
181                  * The table is already known to this KVM, we just increased
182                  * its KVM reference counter and can return.
183                  */
184                 rcu_read_unlock();
185                 fdput(f);
186                 return 0;
187         }
188         rcu_read_unlock();
189 
190         stit = kzalloc(sizeof(*stit), GFP_KERNEL);
191         if (!stit) {
192                 iommu_tce_table_put(tbl);
193                 fdput(f);
194                 return -ENOMEM;
195         }
196 
197         stit->tbl = tbl;
198         kref_init(&stit->kref);
199 
200         list_add_rcu(&stit->next, &stt->iommu_tables);
201 
202         fdput(f);
203         return 0;
204 }
205 
206 static void release_spapr_tce_table(struct rcu_head *head)
207 {
208         struct kvmppc_spapr_tce_table *stt = container_of(head,
209                         struct kvmppc_spapr_tce_table, rcu);
210         unsigned long i, npages = kvmppc_tce_pages(stt->size);
211 
212         for (i = 0; i < npages; i++)
213                 if (stt->pages[i])
214                         __free_page(stt->pages[i]);
215 
216         kfree(stt);
217 }
218 
219 static struct page *kvm_spapr_get_tce_page(struct kvmppc_spapr_tce_table *stt,
220                 unsigned long sttpage)
221 {
222         struct page *page = stt->pages[sttpage];
223 
224         if (page)
225                 return page;
226 
227         mutex_lock(&stt->alloc_lock);
228         page = stt->pages[sttpage];
229         if (!page) {
230                 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
231                 WARN_ON_ONCE(!page);
232                 if (page)
233                         stt->pages[sttpage] = page;
234         }
235         mutex_unlock(&stt->alloc_lock);
236 
237         return page;
238 }
239 
240 static vm_fault_t kvm_spapr_tce_fault(struct vm_fault *vmf)
241 {
242         struct kvmppc_spapr_tce_table *stt = vmf->vma->vm_file->private_data;
243         struct page *page;
244 
245         if (vmf->pgoff >= kvmppc_tce_pages(stt->size))
246                 return VM_FAULT_SIGBUS;
247 
248         page = kvm_spapr_get_tce_page(stt, vmf->pgoff);
249         if (!page)
250                 return VM_FAULT_OOM;
251 
252         get_page(page);
253         vmf->page = page;
254         return 0;
255 }
256 
257 static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
258         .fault = kvm_spapr_tce_fault,
259 };
260 
261 static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma)
262 {
263         vma->vm_ops = &kvm_spapr_tce_vm_ops;
264         return 0;
265 }
266 
267 static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
268 {
269         struct kvmppc_spapr_tce_table *stt = filp->private_data;
270         struct kvmppc_spapr_tce_iommu_table *stit, *tmp;
271         struct kvm *kvm = stt->kvm;
272 
273         mutex_lock(&kvm->lock);
274         list_del_rcu(&stt->list);
275         mutex_unlock(&kvm->lock);
276 
277         list_for_each_entry_safe(stit, tmp, &stt->iommu_tables, next) {
278                 WARN_ON(!kref_read(&stit->kref));
279                 while (1) {
280                         if (kref_put(&stit->kref, kvm_spapr_tce_liobn_put))
281                                 break;
282                 }
283         }
284 
285         account_locked_vm(kvm->mm,
286                 kvmppc_stt_pages(kvmppc_tce_pages(stt->size)), false);
287 
288         kvm_put_kvm(stt->kvm);
289 
290         call_rcu(&stt->rcu, release_spapr_tce_table);
291 
292         return 0;
293 }
294 
295 static const struct file_operations kvm_spapr_tce_fops = {
296         .mmap           = kvm_spapr_tce_mmap,
297         .release        = kvm_spapr_tce_release,
298 };
299 
300 int kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
301                                   struct kvm_create_spapr_tce_64 *args)
302 {
303         struct kvmppc_spapr_tce_table *stt = NULL;
304         struct kvmppc_spapr_tce_table *siter;
305         struct mm_struct *mm = kvm->mm;
306         unsigned long npages;
307         int ret;
308 
309         if (!args->size || args->page_shift < 12 || args->page_shift > 34 ||
310                 (args->offset + args->size > (ULLONG_MAX >> args->page_shift)))
311                 return -EINVAL;
312 
313         npages = kvmppc_tce_pages(args->size);
314         ret = account_locked_vm(mm, kvmppc_stt_pages(npages), true);
315         if (ret)
316                 return ret;
317 
318         ret = -ENOMEM;
319         stt = kzalloc(struct_size(stt, pages, npages), GFP_KERNEL | __GFP_NOWARN);
320         if (!stt)
321                 goto fail_acct;
322 
323         stt->liobn = args->liobn;
324         stt->page_shift = args->page_shift;
325         stt->offset = args->offset;
326         stt->size = args->size;
327         stt->kvm = kvm;
328         mutex_init(&stt->alloc_lock);
329         INIT_LIST_HEAD_RCU(&stt->iommu_tables);
330 
331         mutex_lock(&kvm->lock);
332 
333         /* Check this LIOBN hasn't been previously allocated */
334         ret = 0;
335         list_for_each_entry(siter, &kvm->arch.spapr_tce_tables, list) {
336                 if (siter->liobn == args->liobn) {
337                         ret = -EBUSY;
338                         break;
339                 }
340         }
341 
342         kvm_get_kvm(kvm);
343         if (!ret)
344                 ret = anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
345                                        stt, O_RDWR | O_CLOEXEC);
346 
347         if (ret >= 0)
348                 list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables);
349         else
350                 kvm_put_kvm_no_destroy(kvm);
351 
352         mutex_unlock(&kvm->lock);
353 
354         if (ret >= 0)
355                 return ret;
356 
357         kfree(stt);
358  fail_acct:
359         account_locked_vm(mm, kvmppc_stt_pages(npages), false);
360         return ret;
361 }
362 
363 static long kvmppc_tce_to_ua(struct kvm *kvm, unsigned long tce,
364                 unsigned long *ua)
365 {
366         unsigned long gfn = tce >> PAGE_SHIFT;
367         struct kvm_memory_slot *memslot;
368 
369         memslot = __gfn_to_memslot(kvm_memslots(kvm), gfn);
370         if (!memslot)
371                 return -EINVAL;
372 
373         *ua = __gfn_to_hva_memslot(memslot, gfn) |
374                 (tce & ~(PAGE_MASK | TCE_PCI_READ | TCE_PCI_WRITE));
375 
376         return 0;
377 }
378 
379 static long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt,
380                 unsigned long tce)
381 {
382         unsigned long gpa = tce & ~(TCE_PCI_READ | TCE_PCI_WRITE);
383         enum dma_data_direction dir = iommu_tce_direction(tce);
384         struct kvmppc_spapr_tce_iommu_table *stit;
385         unsigned long ua = 0;
386 
387         /* Allow userspace to poison TCE table */
388         if (dir == DMA_NONE)
389                 return H_SUCCESS;
390 
391         if (iommu_tce_check_gpa(stt->page_shift, gpa))
392                 return H_TOO_HARD;
393 
394         if (kvmppc_tce_to_ua(stt->kvm, tce, &ua))
395                 return H_TOO_HARD;
396 
397         rcu_read_lock();
398         list_for_each_entry_rcu(stit, &stt->iommu_tables, next) {
399                 unsigned long hpa = 0;
400                 struct mm_iommu_table_group_mem_t *mem;
401                 long shift = stit->tbl->it_page_shift;
402 
403                 mem = mm_iommu_lookup(stt->kvm->mm, ua, 1ULL << shift);
404                 if (!mem || mm_iommu_ua_to_hpa(mem, ua, shift, &hpa)) {
405                         rcu_read_unlock();
406                         return H_TOO_HARD;
407                 }
408         }
409         rcu_read_unlock();
410 
411         return H_SUCCESS;
412 }
413 
414 /*
415  * Handles TCE requests for emulated devices.
416  * Puts guest TCE values to the table and expects user space to convert them.
417  * Cannot fail so kvmppc_tce_validate must be called before it.
418  */
419 static void kvmppc_tce_put(struct kvmppc_spapr_tce_table *stt,
420                 unsigned long idx, unsigned long tce)
421 {
422         struct page *page;
423         u64 *tbl;
424         unsigned long sttpage;
425 
426         idx -= stt->offset;
427         sttpage = idx / TCES_PER_PAGE;
428         page = stt->pages[sttpage];
429 
430         if (!page) {
431                 /* We allow any TCE, not just with read|write permissions */
432                 if (!tce)
433                         return;
434 
435                 page = kvm_spapr_get_tce_page(stt, sttpage);
436                 if (!page)
437                         return;
438         }
439         tbl = page_to_virt(page);
440 
441         tbl[idx % TCES_PER_PAGE] = tce;
442 }
443 
444 static void kvmppc_clear_tce(struct mm_struct *mm, struct kvmppc_spapr_tce_table *stt,
445                 struct iommu_table *tbl, unsigned long entry)
446 {
447         unsigned long i;
448         unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift);
449         unsigned long io_entry = entry << (stt->page_shift - tbl->it_page_shift);
450 
451         for (i = 0; i < subpages; ++i) {
452                 unsigned long hpa = 0;
453                 enum dma_data_direction dir = DMA_NONE;
454 
455                 iommu_tce_xchg_no_kill(mm, tbl, io_entry + i, &hpa, &dir);
456         }
457 }
458 
459 static long kvmppc_tce_iommu_mapped_dec(struct kvm *kvm,
460                 struct iommu_table *tbl, unsigned long entry)
461 {
462         struct mm_iommu_table_group_mem_t *mem = NULL;
463         const unsigned long pgsize = 1ULL << tbl->it_page_shift;
464         __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry);
465 
466         if (!pua)
467                 return H_SUCCESS;
468 
469         mem = mm_iommu_lookup(kvm->mm, be64_to_cpu(*pua), pgsize);
470         if (!mem)
471                 return H_TOO_HARD;
472 
473         mm_iommu_mapped_dec(mem);
474 
475         *pua = cpu_to_be64(0);
476 
477         return H_SUCCESS;
478 }
479 
480 static long kvmppc_tce_iommu_do_unmap(struct kvm *kvm,
481                 struct iommu_table *tbl, unsigned long entry)
482 {
483         enum dma_data_direction dir = DMA_NONE;
484         unsigned long hpa = 0;
485         long ret;
486 
487         if (WARN_ON_ONCE(iommu_tce_xchg_no_kill(kvm->mm, tbl, entry, &hpa,
488                                         &dir)))
489                 return H_TOO_HARD;
490 
491         if (dir == DMA_NONE)
492                 return H_SUCCESS;
493 
494         ret = kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry);
495         if (ret != H_SUCCESS)
496                 iommu_tce_xchg_no_kill(kvm->mm, tbl, entry, &hpa, &dir);
497 
498         return ret;
499 }
500 
501 static long kvmppc_tce_iommu_unmap(struct kvm *kvm,
502                 struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl,
503                 unsigned long entry)
504 {
505         unsigned long i, ret = H_SUCCESS;
506         unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift);
507         unsigned long io_entry = entry * subpages;
508 
509         for (i = 0; i < subpages; ++i) {
510                 ret = kvmppc_tce_iommu_do_unmap(kvm, tbl, io_entry + i);
511                 if (ret != H_SUCCESS)
512                         break;
513         }
514 
515         iommu_tce_kill(tbl, io_entry, subpages);
516 
517         return ret;
518 }
519 
520 static long kvmppc_tce_iommu_do_map(struct kvm *kvm, struct iommu_table *tbl,
521                 unsigned long entry, unsigned long ua,
522                 enum dma_data_direction dir)
523 {
524         long ret;
525         unsigned long hpa;
526         __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
527         struct mm_iommu_table_group_mem_t *mem;
528 
529         if (!pua)
530                 /* it_userspace allocation might be delayed */
531                 return H_TOO_HARD;
532 
533         mem = mm_iommu_lookup(kvm->mm, ua, 1ULL << tbl->it_page_shift);
534         if (!mem)
535                 /* This only handles v2 IOMMU type, v1 is handled via ioctl() */
536                 return H_TOO_HARD;
537 
538         if (WARN_ON_ONCE(mm_iommu_ua_to_hpa(mem, ua, tbl->it_page_shift, &hpa)))
539                 return H_TOO_HARD;
540 
541         if (mm_iommu_mapped_inc(mem))
542                 return H_TOO_HARD;
543 
544         ret = iommu_tce_xchg_no_kill(kvm->mm, tbl, entry, &hpa, &dir);
545         if (WARN_ON_ONCE(ret)) {
546                 mm_iommu_mapped_dec(mem);
547                 return H_TOO_HARD;
548         }
549 
550         if (dir != DMA_NONE)
551                 kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry);
552 
553         *pua = cpu_to_be64(ua);
554 
555         return 0;
556 }
557 
558 static long kvmppc_tce_iommu_map(struct kvm *kvm,
559                 struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl,
560                 unsigned long entry, unsigned long ua,
561                 enum dma_data_direction dir)
562 {
563         unsigned long i, pgoff, ret = H_SUCCESS;
564         unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift);
565         unsigned long io_entry = entry * subpages;
566 
567         for (i = 0, pgoff = 0; i < subpages;
568                         ++i, pgoff += IOMMU_PAGE_SIZE(tbl)) {
569 
570                 ret = kvmppc_tce_iommu_do_map(kvm, tbl,
571                                 io_entry + i, ua + pgoff, dir);
572                 if (ret != H_SUCCESS)
573                         break;
574         }
575 
576         iommu_tce_kill(tbl, io_entry, subpages);
577 
578         return ret;
579 }
580 
581 long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
582                       unsigned long ioba, unsigned long tce)
583 {
584         struct kvmppc_spapr_tce_table *stt;
585         long ret, idx;
586         struct kvmppc_spapr_tce_iommu_table *stit;
587         unsigned long entry, ua = 0;
588         enum dma_data_direction dir;
589 
590         /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
591         /*          liobn, ioba, tce); */
592 
593         stt = kvmppc_find_table(vcpu->kvm, liobn);
594         if (!stt)
595                 return H_TOO_HARD;
596 
597         ret = kvmppc_ioba_validate(stt, ioba, 1);
598         if (ret != H_SUCCESS)
599                 return ret;
600 
601         idx = srcu_read_lock(&vcpu->kvm->srcu);
602 
603         ret = kvmppc_tce_validate(stt, tce);
604         if (ret != H_SUCCESS)
605                 goto unlock_exit;
606 
607         dir = iommu_tce_direction(tce);
608 
609         if ((dir != DMA_NONE) && kvmppc_tce_to_ua(vcpu->kvm, tce, &ua)) {
610                 ret = H_PARAMETER;
611                 goto unlock_exit;
612         }
613 
614         entry = ioba >> stt->page_shift;
615 
616         list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
617                 if (dir == DMA_NONE)
618                         ret = kvmppc_tce_iommu_unmap(vcpu->kvm, stt,
619                                         stit->tbl, entry);
620                 else
621                         ret = kvmppc_tce_iommu_map(vcpu->kvm, stt, stit->tbl,
622                                         entry, ua, dir);
623 
624 
625                 if (ret != H_SUCCESS) {
626                         kvmppc_clear_tce(vcpu->kvm->mm, stt, stit->tbl, entry);
627                         goto unlock_exit;
628                 }
629         }
630 
631         kvmppc_tce_put(stt, entry, tce);
632 
633 unlock_exit:
634         srcu_read_unlock(&vcpu->kvm->srcu, idx);
635 
636         return ret;
637 }
638 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce);
639 
640 long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu,
641                 unsigned long liobn, unsigned long ioba,
642                 unsigned long tce_list, unsigned long npages)
643 {
644         struct kvmppc_spapr_tce_table *stt;
645         long i, ret = H_SUCCESS, idx;
646         unsigned long entry, ua = 0;
647         u64 __user *tces;
648         u64 tce;
649         struct kvmppc_spapr_tce_iommu_table *stit;
650 
651         stt = kvmppc_find_table(vcpu->kvm, liobn);
652         if (!stt)
653                 return H_TOO_HARD;
654 
655         entry = ioba >> stt->page_shift;
656         /*
657          * SPAPR spec says that the maximum size of the list is 512 TCEs
658          * so the whole table fits in 4K page
659          */
660         if (npages > 512)
661                 return H_PARAMETER;
662 
663         if (tce_list & (SZ_4K - 1))
664                 return H_PARAMETER;
665 
666         ret = kvmppc_ioba_validate(stt, ioba, npages);
667         if (ret != H_SUCCESS)
668                 return ret;
669 
670         idx = srcu_read_lock(&vcpu->kvm->srcu);
671         if (kvmppc_tce_to_ua(vcpu->kvm, tce_list, &ua)) {
672                 ret = H_TOO_HARD;
673                 goto unlock_exit;
674         }
675         tces = (u64 __user *) ua;
676 
677         for (i = 0; i < npages; ++i) {
678                 if (get_user(tce, tces + i)) {
679                         ret = H_TOO_HARD;
680                         goto unlock_exit;
681                 }
682                 tce = be64_to_cpu(tce);
683 
684                 ret = kvmppc_tce_validate(stt, tce);
685                 if (ret != H_SUCCESS)
686                         goto unlock_exit;
687         }
688 
689         for (i = 0; i < npages; ++i) {
690                 /*
691                  * This looks unsafe, because we validate, then regrab
692                  * the TCE from userspace which could have been changed by
693                  * another thread.
694                  *
695                  * But it actually is safe, because the relevant checks will be
696                  * re-executed in the following code.  If userspace tries to
697                  * change this dodgily it will result in a messier failure mode
698                  * but won't threaten the host.
699                  */
700                 if (get_user(tce, tces + i)) {
701                         ret = H_TOO_HARD;
702                         goto unlock_exit;
703                 }
704                 tce = be64_to_cpu(tce);
705 
706                 if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua)) {
707                         ret = H_PARAMETER;
708                         goto unlock_exit;
709                 }
710 
711                 list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
712                         ret = kvmppc_tce_iommu_map(vcpu->kvm, stt,
713                                         stit->tbl, entry + i, ua,
714                                         iommu_tce_direction(tce));
715 
716                         if (ret != H_SUCCESS) {
717                                 kvmppc_clear_tce(vcpu->kvm->mm, stt, stit->tbl,
718                                                  entry + i);
719                                 goto unlock_exit;
720                         }
721                 }
722 
723                 kvmppc_tce_put(stt, entry + i, tce);
724         }
725 
726 unlock_exit:
727         srcu_read_unlock(&vcpu->kvm->srcu, idx);
728 
729         return ret;
730 }
731 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce_indirect);
732 
733 long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu,
734                 unsigned long liobn, unsigned long ioba,
735                 unsigned long tce_value, unsigned long npages)
736 {
737         struct kvmppc_spapr_tce_table *stt;
738         long i, ret;
739         struct kvmppc_spapr_tce_iommu_table *stit;
740 
741         stt = kvmppc_find_table(vcpu->kvm, liobn);
742         if (!stt)
743                 return H_TOO_HARD;
744 
745         ret = kvmppc_ioba_validate(stt, ioba, npages);
746         if (ret != H_SUCCESS)
747                 return ret;
748 
749         /* Check permission bits only to allow userspace poison TCE for debug */
750         if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
751                 return H_PARAMETER;
752 
753         list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
754                 unsigned long entry = ioba >> stt->page_shift;
755 
756                 for (i = 0; i < npages; ++i) {
757                         ret = kvmppc_tce_iommu_unmap(vcpu->kvm, stt,
758                                         stit->tbl, entry + i);
759 
760                         if (ret == H_SUCCESS)
761                                 continue;
762 
763                         if (ret == H_TOO_HARD)
764                                 return ret;
765 
766                         WARN_ON_ONCE(1);
767                         kvmppc_clear_tce(vcpu->kvm->mm, stt, stit->tbl, entry + i);
768                 }
769         }
770 
771         for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
772                 kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
773 
774         return ret;
775 }
776 EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce);
777 
778 long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
779                       unsigned long ioba)
780 {
781         struct kvmppc_spapr_tce_table *stt;
782         long ret;
783         unsigned long idx;
784         struct page *page;
785         u64 *tbl;
786 
787         stt = kvmppc_find_table(vcpu->kvm, liobn);
788         if (!stt)
789                 return H_TOO_HARD;
790 
791         ret = kvmppc_ioba_validate(stt, ioba, 1);
792         if (ret != H_SUCCESS)
793                 return ret;
794 
795         idx = (ioba >> stt->page_shift) - stt->offset;
796         page = stt->pages[idx / TCES_PER_PAGE];
797         if (!page) {
798                 kvmppc_set_gpr(vcpu, 4, 0);
799                 return H_SUCCESS;
800         }
801         tbl = (u64 *)page_address(page);
802 
803         kvmppc_set_gpr(vcpu, 4, tbl[idx % TCES_PER_PAGE]);
804 
805         return H_SUCCESS;
806 }
807 EXPORT_SYMBOL_GPL(kvmppc_h_get_tce);
808 

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