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1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License, version 2, as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
14 *
15 * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
16 */
17
18 #include <linux/types.h>
19 #include <linux/string.h>
20 #include <linux/kvm.h>
21 #include <linux/kvm_host.h>
22 #include <linux/highmem.h>
23 #include <linux/gfp.h>
24 #include <linux/slab.h>
25 #include <linux/hugetlb.h>
26 #include <linux/vmalloc.h>
27 #include <linux/srcu.h>
28 #include <linux/anon_inodes.h>
29 #include <linux/file.h>
30 #include <linux/debugfs.h>
31
32 #include <asm/tlbflush.h>
33 #include <asm/kvm_ppc.h>
34 #include <asm/kvm_book3s.h>
35 #include <asm/book3s/64/mmu-hash.h>
36 #include <asm/hvcall.h>
37 #include <asm/synch.h>
38 #include <asm/ppc-opcode.h>
39 #include <asm/cputable.h>
40 #include <asm/pte-walk.h>
41
42 #include "trace_hv.h"
43
44 //#define DEBUG_RESIZE_HPT 1
45
46 #ifdef DEBUG_RESIZE_HPT
47 #define resize_hpt_debug(resize, ...) \
48 do { \
49 printk(KERN_DEBUG "RESIZE HPT %p: ", resize); \
50 printk(__VA_ARGS__); \
51 } while (0)
52 #else
53 #define resize_hpt_debug(resize, ...) \
54 do { } while (0)
55 #endif
56
57 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
58 long pte_index, unsigned long pteh,
59 unsigned long ptel, unsigned long *pte_idx_ret);
60
61 struct kvm_resize_hpt {
62 /* These fields read-only after init */
63 struct kvm *kvm;
64 struct work_struct work;
65 u32 order;
66
67 /* These fields protected by kvm->lock */
68 int error;
69 bool prepare_done;
70
71 /* Private to the work thread, until prepare_done is true,
72 * then protected by kvm->resize_hpt_sem */
73 struct kvm_hpt_info hpt;
74 };
75
76 int kvmppc_allocate_hpt(struct kvm_hpt_info *info, u32 order)
77 {
78 unsigned long hpt = 0;
79 int cma = 0;
80 struct page *page = NULL;
81 struct revmap_entry *rev;
82 unsigned long npte;
83
84 if ((order < PPC_MIN_HPT_ORDER) || (order > PPC_MAX_HPT_ORDER))
85 return -EINVAL;
86
87 page = kvm_alloc_hpt_cma(1ul << (order - PAGE_SHIFT));
88 if (page) {
89 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
90 memset((void *)hpt, 0, (1ul << order));
91 cma = 1;
92 }
93
94 if (!hpt)
95 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_RETRY_MAYFAIL
96 |__GFP_NOWARN, order - PAGE_SHIFT);
97
98 if (!hpt)
99 return -ENOMEM;
100
101 /* HPTEs are 2**4 bytes long */
102 npte = 1ul << (order - 4);
103
104 /* Allocate reverse map array */
105 rev = vmalloc(sizeof(struct revmap_entry) * npte);
106 if (!rev) {
107 if (cma)
108 kvm_free_hpt_cma(page, 1 << (order - PAGE_SHIFT));
109 else
110 free_pages(hpt, order - PAGE_SHIFT);
111 return -ENOMEM;
112 }
113
114 info->order = order;
115 info->virt = hpt;
116 info->cma = cma;
117 info->rev = rev;
118
119 return 0;
120 }
121
122 void kvmppc_set_hpt(struct kvm *kvm, struct kvm_hpt_info *info)
123 {
124 atomic64_set(&kvm->arch.mmio_update, 0);
125 kvm->arch.hpt = *info;
126 kvm->arch.sdr1 = __pa(info->virt) | (info->order - 18);
127
128 pr_debug("KVM guest htab at %lx (order %ld), LPID %x\n",
129 info->virt, (long)info->order, kvm->arch.lpid);
130 }
131
132 long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
133 {
134 long err = -EBUSY;
135 struct kvm_hpt_info info;
136
137 mutex_lock(&kvm->lock);
138 if (kvm->arch.mmu_ready) {
139 kvm->arch.mmu_ready = 0;
140 /* order mmu_ready vs. vcpus_running */
141 smp_mb();
142 if (atomic_read(&kvm->arch.vcpus_running)) {
143 kvm->arch.mmu_ready = 1;
144 goto out;
145 }
146 }
147 if (kvm_is_radix(kvm)) {
148 err = kvmppc_switch_mmu_to_hpt(kvm);
149 if (err)
150 goto out;
151 }
152
153 if (kvm->arch.hpt.order == order) {
154 /* We already have a suitable HPT */
155
156 /* Set the entire HPT to 0, i.e. invalid HPTEs */
157 memset((void *)kvm->arch.hpt.virt, 0, 1ul << order);
158 /*
159 * Reset all the reverse-mapping chains for all memslots
160 */
161 kvmppc_rmap_reset(kvm);
162 /* Ensure that each vcpu will flush its TLB on next entry. */
163 cpumask_setall(&kvm->arch.need_tlb_flush);
164 err = 0;
165 goto out;
166 }
167
168 if (kvm->arch.hpt.virt) {
169 kvmppc_free_hpt(&kvm->arch.hpt);
170 kvmppc_rmap_reset(kvm);
171 }
172
173 err = kvmppc_allocate_hpt(&info, order);
174 if (err < 0)
175 goto out;
176 kvmppc_set_hpt(kvm, &info);
177
178 out:
179 mutex_unlock(&kvm->lock);
180 return err;
181 }
182
183 void kvmppc_free_hpt(struct kvm_hpt_info *info)
184 {
185 vfree(info->rev);
186 info->rev = NULL;
187 if (info->cma)
188 kvm_free_hpt_cma(virt_to_page(info->virt),
189 1 << (info->order - PAGE_SHIFT));
190 else if (info->virt)
191 free_pages(info->virt, info->order - PAGE_SHIFT);
192 info->virt = 0;
193 info->order = 0;
194 }
195
196 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
197 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
198 {
199 return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
200 }
201
202 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
203 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
204 {
205 return (pgsize == 0x10000) ? 0x1000 : 0;
206 }
207
208 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
209 unsigned long porder)
210 {
211 unsigned long i;
212 unsigned long npages;
213 unsigned long hp_v, hp_r;
214 unsigned long addr, hash;
215 unsigned long psize;
216 unsigned long hp0, hp1;
217 unsigned long idx_ret;
218 long ret;
219 struct kvm *kvm = vcpu->kvm;
220
221 psize = 1ul << porder;
222 npages = memslot->npages >> (porder - PAGE_SHIFT);
223
224 /* VRMA can't be > 1TB */
225 if (npages > 1ul << (40 - porder))
226 npages = 1ul << (40 - porder);
227 /* Can't use more than 1 HPTE per HPTEG */
228 if (npages > kvmppc_hpt_mask(&kvm->arch.hpt) + 1)
229 npages = kvmppc_hpt_mask(&kvm->arch.hpt) + 1;
230
231 hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
232 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
233 hp1 = hpte1_pgsize_encoding(psize) |
234 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
235
236 for (i = 0; i < npages; ++i) {
237 addr = i << porder;
238 /* can't use hpt_hash since va > 64 bits */
239 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25)))
240 & kvmppc_hpt_mask(&kvm->arch.hpt);
241 /*
242 * We assume that the hash table is empty and no
243 * vcpus are using it at this stage. Since we create
244 * at most one HPTE per HPTEG, we just assume entry 7
245 * is available and use it.
246 */
247 hash = (hash << 3) + 7;
248 hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
249 hp_r = hp1 | addr;
250 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
251 &idx_ret);
252 if (ret != H_SUCCESS) {
253 pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
254 addr, ret);
255 break;
256 }
257 }
258 }
259
260 int kvmppc_mmu_hv_init(void)
261 {
262 unsigned long host_lpid, rsvd_lpid;
263
264 if (!cpu_has_feature(CPU_FTR_HVMODE))
265 return -EINVAL;
266
267 /* POWER7 has 10-bit LPIDs (12-bit in POWER8) */
268 host_lpid = mfspr(SPRN_LPID);
269 rsvd_lpid = LPID_RSVD;
270
271 kvmppc_init_lpid(rsvd_lpid + 1);
272
273 kvmppc_claim_lpid(host_lpid);
274 /* rsvd_lpid is reserved for use in partition switching */
275 kvmppc_claim_lpid(rsvd_lpid);
276
277 return 0;
278 }
279
280 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
281 {
282 unsigned long msr = vcpu->arch.intr_msr;
283
284 /* If transactional, change to suspend mode on IRQ delivery */
285 if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
286 msr |= MSR_TS_S;
287 else
288 msr |= vcpu->arch.shregs.msr & MSR_TS_MASK;
289 kvmppc_set_msr(vcpu, msr);
290 }
291
292 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
293 long pte_index, unsigned long pteh,
294 unsigned long ptel, unsigned long *pte_idx_ret)
295 {
296 long ret;
297
298 /* Protect linux PTE lookup from page table destruction */
299 rcu_read_lock_sched(); /* this disables preemption too */
300 ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
301 current->mm->pgd, false, pte_idx_ret);
302 rcu_read_unlock_sched();
303 if (ret == H_TOO_HARD) {
304 /* this can't happen */
305 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
306 ret = H_RESOURCE; /* or something */
307 }
308 return ret;
309
310 }
311
312 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
313 gva_t eaddr)
314 {
315 u64 mask;
316 int i;
317
318 for (i = 0; i < vcpu->arch.slb_nr; i++) {
319 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
320 continue;
321
322 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
323 mask = ESID_MASK_1T;
324 else
325 mask = ESID_MASK;
326
327 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
328 return &vcpu->arch.slb[i];
329 }
330 return NULL;
331 }
332
333 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
334 unsigned long ea)
335 {
336 unsigned long ra_mask;
337
338 ra_mask = kvmppc_actual_pgsz(v, r) - 1;
339 return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
340 }
341
342 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
343 struct kvmppc_pte *gpte, bool data, bool iswrite)
344 {
345 struct kvm *kvm = vcpu->kvm;
346 struct kvmppc_slb *slbe;
347 unsigned long slb_v;
348 unsigned long pp, key;
349 unsigned long v, orig_v, gr;
350 __be64 *hptep;
351 int index;
352 int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
353
354 if (kvm_is_radix(vcpu->kvm))
355 return kvmppc_mmu_radix_xlate(vcpu, eaddr, gpte, data, iswrite);
356
357 /* Get SLB entry */
358 if (virtmode) {
359 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
360 if (!slbe)
361 return -EINVAL;
362 slb_v = slbe->origv;
363 } else {
364 /* real mode access */
365 slb_v = vcpu->kvm->arch.vrma_slb_v;
366 }
367
368 preempt_disable();
369 /* Find the HPTE in the hash table */
370 index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
371 HPTE_V_VALID | HPTE_V_ABSENT);
372 if (index < 0) {
373 preempt_enable();
374 return -ENOENT;
375 }
376 hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
377 v = orig_v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
378 if (cpu_has_feature(CPU_FTR_ARCH_300))
379 v = hpte_new_to_old_v(v, be64_to_cpu(hptep[1]));
380 gr = kvm->arch.hpt.rev[index].guest_rpte;
381
382 unlock_hpte(hptep, orig_v);
383 preempt_enable();
384
385 gpte->eaddr = eaddr;
386 gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
387
388 /* Get PP bits and key for permission check */
389 pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
390 key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
391 key &= slb_v;
392
393 /* Calculate permissions */
394 gpte->may_read = hpte_read_permission(pp, key);
395 gpte->may_write = hpte_write_permission(pp, key);
396 gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
397
398 /* Storage key permission check for POWER7 */
399 if (data && virtmode) {
400 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
401 if (amrfield & 1)
402 gpte->may_read = 0;
403 if (amrfield & 2)
404 gpte->may_write = 0;
405 }
406
407 /* Get the guest physical address */
408 gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
409 return 0;
410 }
411
412 /*
413 * Quick test for whether an instruction is a load or a store.
414 * If the instruction is a load or a store, then this will indicate
415 * which it is, at least on server processors. (Embedded processors
416 * have some external PID instructions that don't follow the rule
417 * embodied here.) If the instruction isn't a load or store, then
418 * this doesn't return anything useful.
419 */
420 static int instruction_is_store(unsigned int instr)
421 {
422 unsigned int mask;
423
424 mask = 0x10000000;
425 if ((instr & 0xfc000000) == 0x7c000000)
426 mask = 0x100; /* major opcode 31 */
427 return (instr & mask) != 0;
428 }
429
430 int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
431 unsigned long gpa, gva_t ea, int is_store)
432 {
433 u32 last_inst;
434
435 /*
436 * If we fail, we just return to the guest and try executing it again.
437 */
438 if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
439 EMULATE_DONE)
440 return RESUME_GUEST;
441
442 /*
443 * WARNING: We do not know for sure whether the instruction we just
444 * read from memory is the same that caused the fault in the first
445 * place. If the instruction we read is neither an load or a store,
446 * then it can't access memory, so we don't need to worry about
447 * enforcing access permissions. So, assuming it is a load or
448 * store, we just check that its direction (load or store) is
449 * consistent with the original fault, since that's what we
450 * checked the access permissions against. If there is a mismatch
451 * we just return and retry the instruction.
452 */
453
454 if (instruction_is_store(last_inst) != !!is_store)
455 return RESUME_GUEST;
456
457 /*
458 * Emulated accesses are emulated by looking at the hash for
459 * translation once, then performing the access later. The
460 * translation could be invalidated in the meantime in which
461 * point performing the subsequent memory access on the old
462 * physical address could possibly be a security hole for the
463 * guest (but not the host).
464 *
465 * This is less of an issue for MMIO stores since they aren't
466 * globally visible. It could be an issue for MMIO loads to
467 * a certain extent but we'll ignore it for now.
468 */
469
470 vcpu->arch.paddr_accessed = gpa;
471 vcpu->arch.vaddr_accessed = ea;
472 return kvmppc_emulate_mmio(run, vcpu);
473 }
474
475 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
476 unsigned long ea, unsigned long dsisr)
477 {
478 struct kvm *kvm = vcpu->kvm;
479 unsigned long hpte[3], r;
480 unsigned long hnow_v, hnow_r;
481 __be64 *hptep;
482 unsigned long mmu_seq, psize, pte_size;
483 unsigned long gpa_base, gfn_base;
484 unsigned long gpa, gfn, hva, pfn;
485 struct kvm_memory_slot *memslot;
486 unsigned long *rmap;
487 struct revmap_entry *rev;
488 struct page *page, *pages[1];
489 long index, ret, npages;
490 bool is_ci;
491 unsigned int writing, write_ok;
492 struct vm_area_struct *vma;
493 unsigned long rcbits;
494 long mmio_update;
495
496 if (kvm_is_radix(kvm))
497 return kvmppc_book3s_radix_page_fault(run, vcpu, ea, dsisr);
498
499 /*
500 * Real-mode code has already searched the HPT and found the
501 * entry we're interested in. Lock the entry and check that
502 * it hasn't changed. If it has, just return and re-execute the
503 * instruction.
504 */
505 if (ea != vcpu->arch.pgfault_addr)
506 return RESUME_GUEST;
507
508 if (vcpu->arch.pgfault_cache) {
509 mmio_update = atomic64_read(&kvm->arch.mmio_update);
510 if (mmio_update == vcpu->arch.pgfault_cache->mmio_update) {
511 r = vcpu->arch.pgfault_cache->rpte;
512 psize = kvmppc_actual_pgsz(vcpu->arch.pgfault_hpte[0],
513 r);
514 gpa_base = r & HPTE_R_RPN & ~(psize - 1);
515 gfn_base = gpa_base >> PAGE_SHIFT;
516 gpa = gpa_base | (ea & (psize - 1));
517 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
518 dsisr & DSISR_ISSTORE);
519 }
520 }
521 index = vcpu->arch.pgfault_index;
522 hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
523 rev = &kvm->arch.hpt.rev[index];
524 preempt_disable();
525 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
526 cpu_relax();
527 hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
528 hpte[1] = be64_to_cpu(hptep[1]);
529 hpte[2] = r = rev->guest_rpte;
530 unlock_hpte(hptep, hpte[0]);
531 preempt_enable();
532
533 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
534 hpte[0] = hpte_new_to_old_v(hpte[0], hpte[1]);
535 hpte[1] = hpte_new_to_old_r(hpte[1]);
536 }
537 if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
538 hpte[1] != vcpu->arch.pgfault_hpte[1])
539 return RESUME_GUEST;
540
541 /* Translate the logical address and get the page */
542 psize = kvmppc_actual_pgsz(hpte[0], r);
543 gpa_base = r & HPTE_R_RPN & ~(psize - 1);
544 gfn_base = gpa_base >> PAGE_SHIFT;
545 gpa = gpa_base | (ea & (psize - 1));
546 gfn = gpa >> PAGE_SHIFT;
547 memslot = gfn_to_memslot(kvm, gfn);
548
549 trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr);
550
551 /* No memslot means it's an emulated MMIO region */
552 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
553 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
554 dsisr & DSISR_ISSTORE);
555
556 /*
557 * This should never happen, because of the slot_is_aligned()
558 * check in kvmppc_do_h_enter().
559 */
560 if (gfn_base < memslot->base_gfn)
561 return -EFAULT;
562
563 /* used to check for invalidations in progress */
564 mmu_seq = kvm->mmu_notifier_seq;
565 smp_rmb();
566
567 ret = -EFAULT;
568 is_ci = false;
569 pfn = 0;
570 page = NULL;
571 pte_size = PAGE_SIZE;
572 writing = (dsisr & DSISR_ISSTORE) != 0;
573 /* If writing != 0, then the HPTE must allow writing, if we get here */
574 write_ok = writing;
575 hva = gfn_to_hva_memslot(memslot, gfn);
576 npages = get_user_pages_fast(hva, 1, writing, pages);
577 if (npages < 1) {
578 /* Check if it's an I/O mapping */
579 down_read(&current->mm->mmap_sem);
580 vma = find_vma(current->mm, hva);
581 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
582 (vma->vm_flags & VM_PFNMAP)) {
583 pfn = vma->vm_pgoff +
584 ((hva - vma->vm_start) >> PAGE_SHIFT);
585 pte_size = psize;
586 is_ci = pte_ci(__pte((pgprot_val(vma->vm_page_prot))));
587 write_ok = vma->vm_flags & VM_WRITE;
588 }
589 up_read(&current->mm->mmap_sem);
590 if (!pfn)
591 goto out_put;
592 } else {
593 page = pages[0];
594 pfn = page_to_pfn(page);
595 if (PageHuge(page)) {
596 page = compound_head(page);
597 pte_size <<= compound_order(page);
598 }
599 /* if the guest wants write access, see if that is OK */
600 if (!writing && hpte_is_writable(r)) {
601 pte_t *ptep, pte;
602 unsigned long flags;
603 /*
604 * We need to protect against page table destruction
605 * hugepage split and collapse.
606 */
607 local_irq_save(flags);
608 ptep = find_current_mm_pte(current->mm->pgd,
609 hva, NULL, NULL);
610 if (ptep) {
611 pte = kvmppc_read_update_linux_pte(ptep, 1);
612 if (__pte_write(pte))
613 write_ok = 1;
614 }
615 local_irq_restore(flags);
616 }
617 }
618
619 if (psize > pte_size)
620 goto out_put;
621
622 /* Check WIMG vs. the actual page we're accessing */
623 if (!hpte_cache_flags_ok(r, is_ci)) {
624 if (is_ci)
625 goto out_put;
626 /*
627 * Allow guest to map emulated device memory as
628 * uncacheable, but actually make it cacheable.
629 */
630 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
631 }
632
633 /*
634 * Set the HPTE to point to pfn.
635 * Since the pfn is at PAGE_SIZE granularity, make sure we
636 * don't mask out lower-order bits if psize < PAGE_SIZE.
637 */
638 if (psize < PAGE_SIZE)
639 psize = PAGE_SIZE;
640 r = (r & HPTE_R_KEY_HI) | (r & ~(HPTE_R_PP0 - psize)) |
641 ((pfn << PAGE_SHIFT) & ~(psize - 1));
642 if (hpte_is_writable(r) && !write_ok)
643 r = hpte_make_readonly(r);
644 ret = RESUME_GUEST;
645 preempt_disable();
646 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
647 cpu_relax();
648 hnow_v = be64_to_cpu(hptep[0]);
649 hnow_r = be64_to_cpu(hptep[1]);
650 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
651 hnow_v = hpte_new_to_old_v(hnow_v, hnow_r);
652 hnow_r = hpte_new_to_old_r(hnow_r);
653 }
654
655 /*
656 * If the HPT is being resized, don't update the HPTE,
657 * instead let the guest retry after the resize operation is complete.
658 * The synchronization for mmu_ready test vs. set is provided
659 * by the HPTE lock.
660 */
661 if (!kvm->arch.mmu_ready)
662 goto out_unlock;
663
664 if ((hnow_v & ~HPTE_V_HVLOCK) != hpte[0] || hnow_r != hpte[1] ||
665 rev->guest_rpte != hpte[2])
666 /* HPTE has been changed under us; let the guest retry */
667 goto out_unlock;
668 hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
669
670 /* Always put the HPTE in the rmap chain for the page base address */
671 rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn];
672 lock_rmap(rmap);
673
674 /* Check if we might have been invalidated; let the guest retry if so */
675 ret = RESUME_GUEST;
676 if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
677 unlock_rmap(rmap);
678 goto out_unlock;
679 }
680
681 /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
682 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
683 r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
684
685 if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) {
686 /* HPTE was previously valid, so we need to invalidate it */
687 unlock_rmap(rmap);
688 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
689 kvmppc_invalidate_hpte(kvm, hptep, index);
690 /* don't lose previous R and C bits */
691 r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
692 } else {
693 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
694 }
695
696 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
697 r = hpte_old_to_new_r(hpte[0], r);
698 hpte[0] = hpte_old_to_new_v(hpte[0]);
699 }
700 hptep[1] = cpu_to_be64(r);
701 eieio();
702 __unlock_hpte(hptep, hpte[0]);
703 asm volatile("ptesync" : : : "memory");
704 preempt_enable();
705 if (page && hpte_is_writable(r))
706 SetPageDirty(page);
707
708 out_put:
709 trace_kvm_page_fault_exit(vcpu, hpte, ret);
710
711 if (page) {
712 /*
713 * We drop pages[0] here, not page because page might
714 * have been set to the head page of a compound, but
715 * we have to drop the reference on the correct tail
716 * page to match the get inside gup()
717 */
718 put_page(pages[0]);
719 }
720 return ret;
721
722 out_unlock:
723 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
724 preempt_enable();
725 goto out_put;
726 }
727
728 void kvmppc_rmap_reset(struct kvm *kvm)
729 {
730 struct kvm_memslots *slots;
731 struct kvm_memory_slot *memslot;
732 int srcu_idx;
733
734 srcu_idx = srcu_read_lock(&kvm->srcu);
735 slots = kvm_memslots(kvm);
736 kvm_for_each_memslot(memslot, slots) {
737 /*
738 * This assumes it is acceptable to lose reference and
739 * change bits across a reset.
740 */
741 memset(memslot->arch.rmap, 0,
742 memslot->npages * sizeof(*memslot->arch.rmap));
743 }
744 srcu_read_unlock(&kvm->srcu, srcu_idx);
745 }
746
747 typedef int (*hva_handler_fn)(struct kvm *kvm, struct kvm_memory_slot *memslot,
748 unsigned long gfn);
749
750 static int kvm_handle_hva_range(struct kvm *kvm,
751 unsigned long start,
752 unsigned long end,
753 hva_handler_fn handler)
754 {
755 int ret;
756 int retval = 0;
757 struct kvm_memslots *slots;
758 struct kvm_memory_slot *memslot;
759
760 slots = kvm_memslots(kvm);
761 kvm_for_each_memslot(memslot, slots) {
762 unsigned long hva_start, hva_end;
763 gfn_t gfn, gfn_end;
764
765 hva_start = max(start, memslot->userspace_addr);
766 hva_end = min(end, memslot->userspace_addr +
767 (memslot->npages << PAGE_SHIFT));
768 if (hva_start >= hva_end)
769 continue;
770 /*
771 * {gfn(page) | page intersects with [hva_start, hva_end)} =
772 * {gfn, gfn+1, ..., gfn_end-1}.
773 */
774 gfn = hva_to_gfn_memslot(hva_start, memslot);
775 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
776
777 for (; gfn < gfn_end; ++gfn) {
778 ret = handler(kvm, memslot, gfn);
779 retval |= ret;
780 }
781 }
782
783 return retval;
784 }
785
786 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
787 hva_handler_fn handler)
788 {
789 return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
790 }
791
792 /* Must be called with both HPTE and rmap locked */
793 static void kvmppc_unmap_hpte(struct kvm *kvm, unsigned long i,
794 struct kvm_memory_slot *memslot,
795 unsigned long *rmapp, unsigned long gfn)
796 {
797 __be64 *hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
798 struct revmap_entry *rev = kvm->arch.hpt.rev;
799 unsigned long j, h;
800 unsigned long ptel, psize, rcbits;
801
802 j = rev[i].forw;
803 if (j == i) {
804 /* chain is now empty */
805 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
806 } else {
807 /* remove i from chain */
808 h = rev[i].back;
809 rev[h].forw = j;
810 rev[j].back = h;
811 rev[i].forw = rev[i].back = i;
812 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
813 }
814
815 /* Now check and modify the HPTE */
816 ptel = rev[i].guest_rpte;
817 psize = kvmppc_actual_pgsz(be64_to_cpu(hptep[0]), ptel);
818 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
819 hpte_rpn(ptel, psize) == gfn) {
820 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
821 kvmppc_invalidate_hpte(kvm, hptep, i);
822 hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
823 /* Harvest R and C */
824 rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
825 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
826 if ((rcbits & HPTE_R_C) && memslot->dirty_bitmap)
827 kvmppc_update_dirty_map(memslot, gfn, psize);
828 if (rcbits & ~rev[i].guest_rpte) {
829 rev[i].guest_rpte = ptel | rcbits;
830 note_hpte_modification(kvm, &rev[i]);
831 }
832 }
833 }
834
835 static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
836 unsigned long gfn)
837 {
838 unsigned long i;
839 __be64 *hptep;
840 unsigned long *rmapp;
841
842 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
843 for (;;) {
844 lock_rmap(rmapp);
845 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
846 unlock_rmap(rmapp);
847 break;
848 }
849
850 /*
851 * To avoid an ABBA deadlock with the HPTE lock bit,
852 * we can't spin on the HPTE lock while holding the
853 * rmap chain lock.
854 */
855 i = *rmapp & KVMPPC_RMAP_INDEX;
856 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
857 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
858 /* unlock rmap before spinning on the HPTE lock */
859 unlock_rmap(rmapp);
860 while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
861 cpu_relax();
862 continue;
863 }
864
865 kvmppc_unmap_hpte(kvm, i, memslot, rmapp, gfn);
866 unlock_rmap(rmapp);
867 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
868 }
869 return 0;
870 }
871
872 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva)
873 {
874 hva_handler_fn handler;
875
876 handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
877 kvm_handle_hva(kvm, hva, handler);
878 return 0;
879 }
880
881 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end)
882 {
883 hva_handler_fn handler;
884
885 handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
886 kvm_handle_hva_range(kvm, start, end, handler);
887 return 0;
888 }
889
890 void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
891 struct kvm_memory_slot *memslot)
892 {
893 unsigned long gfn;
894 unsigned long n;
895 unsigned long *rmapp;
896
897 gfn = memslot->base_gfn;
898 rmapp = memslot->arch.rmap;
899 for (n = memslot->npages; n; --n, ++gfn) {
900 if (kvm_is_radix(kvm)) {
901 kvm_unmap_radix(kvm, memslot, gfn);
902 continue;
903 }
904 /*
905 * Testing the present bit without locking is OK because
906 * the memslot has been marked invalid already, and hence
907 * no new HPTEs referencing this page can be created,
908 * thus the present bit can't go from 0 to 1.
909 */
910 if (*rmapp & KVMPPC_RMAP_PRESENT)
911 kvm_unmap_rmapp(kvm, memslot, gfn);
912 ++rmapp;
913 }
914 }
915
916 static int kvm_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
917 unsigned long gfn)
918 {
919 struct revmap_entry *rev = kvm->arch.hpt.rev;
920 unsigned long head, i, j;
921 __be64 *hptep;
922 int ret = 0;
923 unsigned long *rmapp;
924
925 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
926 retry:
927 lock_rmap(rmapp);
928 if (*rmapp & KVMPPC_RMAP_REFERENCED) {
929 *rmapp &= ~KVMPPC_RMAP_REFERENCED;
930 ret = 1;
931 }
932 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
933 unlock_rmap(rmapp);
934 return ret;
935 }
936
937 i = head = *rmapp & KVMPPC_RMAP_INDEX;
938 do {
939 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
940 j = rev[i].forw;
941
942 /* If this HPTE isn't referenced, ignore it */
943 if (!(be64_to_cpu(hptep[1]) & HPTE_R_R))
944 continue;
945
946 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
947 /* unlock rmap before spinning on the HPTE lock */
948 unlock_rmap(rmapp);
949 while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
950 cpu_relax();
951 goto retry;
952 }
953
954 /* Now check and modify the HPTE */
955 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
956 (be64_to_cpu(hptep[1]) & HPTE_R_R)) {
957 kvmppc_clear_ref_hpte(kvm, hptep, i);
958 if (!(rev[i].guest_rpte & HPTE_R_R)) {
959 rev[i].guest_rpte |= HPTE_R_R;
960 note_hpte_modification(kvm, &rev[i]);
961 }
962 ret = 1;
963 }
964 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
965 } while ((i = j) != head);
966
967 unlock_rmap(rmapp);
968 return ret;
969 }
970
971 int kvm_age_hva_hv(struct kvm *kvm, unsigned long start, unsigned long end)
972 {
973 hva_handler_fn handler;
974
975 handler = kvm_is_radix(kvm) ? kvm_age_radix : kvm_age_rmapp;
976 return kvm_handle_hva_range(kvm, start, end, handler);
977 }
978
979 static int kvm_test_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
980 unsigned long gfn)
981 {
982 struct revmap_entry *rev = kvm->arch.hpt.rev;
983 unsigned long head, i, j;
984 unsigned long *hp;
985 int ret = 1;
986 unsigned long *rmapp;
987
988 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
989 if (*rmapp & KVMPPC_RMAP_REFERENCED)
990 return 1;
991
992 lock_rmap(rmapp);
993 if (*rmapp & KVMPPC_RMAP_REFERENCED)
994 goto out;
995
996 if (*rmapp & KVMPPC_RMAP_PRESENT) {
997 i = head = *rmapp & KVMPPC_RMAP_INDEX;
998 do {
999 hp = (unsigned long *)(kvm->arch.hpt.virt + (i << 4));
1000 j = rev[i].forw;
1001 if (be64_to_cpu(hp[1]) & HPTE_R_R)
1002 goto out;
1003 } while ((i = j) != head);
1004 }
1005 ret = 0;
1006
1007 out:
1008 unlock_rmap(rmapp);
1009 return ret;
1010 }
1011
1012 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva)
1013 {
1014 hva_handler_fn handler;
1015
1016 handler = kvm_is_radix(kvm) ? kvm_test_age_radix : kvm_test_age_rmapp;
1017 return kvm_handle_hva(kvm, hva, handler);
1018 }
1019
1020 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte)
1021 {
1022 hva_handler_fn handler;
1023
1024 handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
1025 kvm_handle_hva(kvm, hva, handler);
1026 }
1027
1028 static int vcpus_running(struct kvm *kvm)
1029 {
1030 return atomic_read(&kvm->arch.vcpus_running) != 0;
1031 }
1032
1033 /*
1034 * Returns the number of system pages that are dirty.
1035 * This can be more than 1 if we find a huge-page HPTE.
1036 */
1037 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
1038 {
1039 struct revmap_entry *rev = kvm->arch.hpt.rev;
1040 unsigned long head, i, j;
1041 unsigned long n;
1042 unsigned long v, r;
1043 __be64 *hptep;
1044 int npages_dirty = 0;
1045
1046 retry:
1047 lock_rmap(rmapp);
1048 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
1049 unlock_rmap(rmapp);
1050 return npages_dirty;
1051 }
1052
1053 i = head = *rmapp & KVMPPC_RMAP_INDEX;
1054 do {
1055 unsigned long hptep1;
1056 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
1057 j = rev[i].forw;
1058
1059 /*
1060 * Checking the C (changed) bit here is racy since there
1061 * is no guarantee about when the hardware writes it back.
1062 * If the HPTE is not writable then it is stable since the
1063 * page can't be written to, and we would have done a tlbie
1064 * (which forces the hardware to complete any writeback)
1065 * when making the HPTE read-only.
1066 * If vcpus are running then this call is racy anyway
1067 * since the page could get dirtied subsequently, so we
1068 * expect there to be a further call which would pick up
1069 * any delayed C bit writeback.
1070 * Otherwise we need to do the tlbie even if C==0 in
1071 * order to pick up any delayed writeback of C.
1072 */
1073 hptep1 = be64_to_cpu(hptep[1]);
1074 if (!(hptep1 & HPTE_R_C) &&
1075 (!hpte_is_writable(hptep1) || vcpus_running(kvm)))
1076 continue;
1077
1078 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
1079 /* unlock rmap before spinning on the HPTE lock */
1080 unlock_rmap(rmapp);
1081 while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK))
1082 cpu_relax();
1083 goto retry;
1084 }
1085
1086 /* Now check and modify the HPTE */
1087 if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) {
1088 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
1089 continue;
1090 }
1091
1092 /* need to make it temporarily absent so C is stable */
1093 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
1094 kvmppc_invalidate_hpte(kvm, hptep, i);
1095 v = be64_to_cpu(hptep[0]);
1096 r = be64_to_cpu(hptep[1]);
1097 if (r & HPTE_R_C) {
1098 hptep[1] = cpu_to_be64(r & ~HPTE_R_C);
1099 if (!(rev[i].guest_rpte & HPTE_R_C)) {
1100 rev[i].guest_rpte |= HPTE_R_C;
1101 note_hpte_modification(kvm, &rev[i]);
1102 }
1103 n = kvmppc_actual_pgsz(v, r);
1104 n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT;
1105 if (n > npages_dirty)
1106 npages_dirty = n;
1107 eieio();
1108 }
1109 v &= ~HPTE_V_ABSENT;
1110 v |= HPTE_V_VALID;
1111 __unlock_hpte(hptep, v);
1112 } while ((i = j) != head);
1113
1114 unlock_rmap(rmapp);
1115 return npages_dirty;
1116 }
1117
1118 void kvmppc_harvest_vpa_dirty(struct kvmppc_vpa *vpa,
1119 struct kvm_memory_slot *memslot,
1120 unsigned long *map)
1121 {
1122 unsigned long gfn;
1123
1124 if (!vpa->dirty || !vpa->pinned_addr)
1125 return;
1126 gfn = vpa->gpa >> PAGE_SHIFT;
1127 if (gfn < memslot->base_gfn ||
1128 gfn >= memslot->base_gfn + memslot->npages)
1129 return;
1130
1131 vpa->dirty = false;
1132 if (map)
1133 __set_bit_le(gfn - memslot->base_gfn, map);
1134 }
1135
1136 long kvmppc_hv_get_dirty_log_hpt(struct kvm *kvm,
1137 struct kvm_memory_slot *memslot, unsigned long *map)
1138 {
1139 unsigned long i;
1140 unsigned long *rmapp;
1141
1142 preempt_disable();
1143 rmapp = memslot->arch.rmap;
1144 for (i = 0; i < memslot->npages; ++i) {
1145 int npages = kvm_test_clear_dirty_npages(kvm, rmapp);
1146 /*
1147 * Note that if npages > 0 then i must be a multiple of npages,
1148 * since we always put huge-page HPTEs in the rmap chain
1149 * corresponding to their page base address.
1150 */
1151 if (npages)
1152 set_dirty_bits(map, i, npages);
1153 ++rmapp;
1154 }
1155 preempt_enable();
1156 return 0;
1157 }
1158
1159 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
1160 unsigned long *nb_ret)
1161 {
1162 struct kvm_memory_slot *memslot;
1163 unsigned long gfn = gpa >> PAGE_SHIFT;
1164 struct page *page, *pages[1];
1165 int npages;
1166 unsigned long hva, offset;
1167 int srcu_idx;
1168
1169 srcu_idx = srcu_read_lock(&kvm->srcu);
1170 memslot = gfn_to_memslot(kvm, gfn);
1171 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
1172 goto err;
1173 hva = gfn_to_hva_memslot(memslot, gfn);
1174 npages = get_user_pages_fast(hva, 1, 1, pages);
1175 if (npages < 1)
1176 goto err;
1177 page = pages[0];
1178 srcu_read_unlock(&kvm->srcu, srcu_idx);
1179
1180 offset = gpa & (PAGE_SIZE - 1);
1181 if (nb_ret)
1182 *nb_ret = PAGE_SIZE - offset;
1183 return page_address(page) + offset;
1184
1185 err:
1186 srcu_read_unlock(&kvm->srcu, srcu_idx);
1187 return NULL;
1188 }
1189
1190 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
1191 bool dirty)
1192 {
1193 struct page *page = virt_to_page(va);
1194 struct kvm_memory_slot *memslot;
1195 unsigned long gfn;
1196 int srcu_idx;
1197
1198 put_page(page);
1199
1200 if (!dirty)
1201 return;
1202
1203 /* We need to mark this page dirty in the memslot dirty_bitmap, if any */
1204 gfn = gpa >> PAGE_SHIFT;
1205 srcu_idx = srcu_read_lock(&kvm->srcu);
1206 memslot = gfn_to_memslot(kvm, gfn);
1207 if (memslot && memslot->dirty_bitmap)
1208 set_bit_le(gfn - memslot->base_gfn, memslot->dirty_bitmap);
1209 srcu_read_unlock(&kvm->srcu, srcu_idx);
1210 }
1211
1212 /*
1213 * HPT resizing
1214 */
1215 static int resize_hpt_allocate(struct kvm_resize_hpt *resize)
1216 {
1217 int rc;
1218
1219 rc = kvmppc_allocate_hpt(&resize->hpt, resize->order);
1220 if (rc < 0)
1221 return rc;
1222
1223 resize_hpt_debug(resize, "resize_hpt_allocate(): HPT @ 0x%lx\n",
1224 resize->hpt.virt);
1225
1226 return 0;
1227 }
1228
1229 static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize,
1230 unsigned long idx)
1231 {
1232 struct kvm *kvm = resize->kvm;
1233 struct kvm_hpt_info *old = &kvm->arch.hpt;
1234 struct kvm_hpt_info *new = &resize->hpt;
1235 unsigned long old_hash_mask = (1ULL << (old->order - 7)) - 1;
1236 unsigned long new_hash_mask = (1ULL << (new->order - 7)) - 1;
1237 __be64 *hptep, *new_hptep;
1238 unsigned long vpte, rpte, guest_rpte;
1239 int ret;
1240 struct revmap_entry *rev;
1241 unsigned long apsize, psize, avpn, pteg, hash;
1242 unsigned long new_idx, new_pteg, replace_vpte;
1243
1244 hptep = (__be64 *)(old->virt + (idx << 4));
1245
1246 /* Guest is stopped, so new HPTEs can't be added or faulted
1247 * in, only unmapped or altered by host actions. So, it's
1248 * safe to check this before we take the HPTE lock */
1249 vpte = be64_to_cpu(hptep[0]);
1250 if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
1251 return 0; /* nothing to do */
1252
1253 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
1254 cpu_relax();
1255
1256 vpte = be64_to_cpu(hptep[0]);
1257
1258 ret = 0;
1259 if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
1260 /* Nothing to do */
1261 goto out;
1262
1263 /* Unmap */
1264 rev = &old->rev[idx];
1265 guest_rpte = rev->guest_rpte;
1266
1267 ret = -EIO;
1268 apsize = kvmppc_actual_pgsz(vpte, guest_rpte);
1269 if (!apsize)
1270 goto out;
1271
1272 if (vpte & HPTE_V_VALID) {
1273 unsigned long gfn = hpte_rpn(guest_rpte, apsize);
1274 int srcu_idx = srcu_read_lock(&kvm->srcu);
1275 struct kvm_memory_slot *memslot =
1276 __gfn_to_memslot(kvm_memslots(kvm), gfn);
1277
1278 if (memslot) {
1279 unsigned long *rmapp;
1280 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1281
1282 lock_rmap(rmapp);
1283 kvmppc_unmap_hpte(kvm, idx, memslot, rmapp, gfn);
1284 unlock_rmap(rmapp);
1285 }
1286
1287 srcu_read_unlock(&kvm->srcu, srcu_idx);
1288 }
1289
1290 /* Reload PTE after unmap */
1291 vpte = be64_to_cpu(hptep[0]);
1292
1293 BUG_ON(vpte & HPTE_V_VALID);
1294 BUG_ON(!(vpte & HPTE_V_ABSENT));
1295
1296 ret = 0;
1297 if (!(vpte & HPTE_V_BOLTED))
1298 goto out;
1299
1300 rpte = be64_to_cpu(hptep[1]);
1301 psize = hpte_base_page_size(vpte, rpte);
1302 avpn = HPTE_V_AVPN_VAL(vpte) & ~((psize - 1) >> 23);
1303 pteg = idx / HPTES_PER_GROUP;
1304 if (vpte & HPTE_V_SECONDARY)
1305 pteg = ~pteg;
1306
1307 if (!(vpte & HPTE_V_1TB_SEG)) {
1308 unsigned long offset, vsid;
1309
1310 /* We only have 28 - 23 bits of offset in avpn */
1311 offset = (avpn & 0x1f) << 23;
1312 vsid = avpn >> 5;
1313 /* We can find more bits from the pteg value */
1314 if (psize < (1ULL << 23))
1315 offset |= ((vsid ^ pteg) & old_hash_mask) * psize;
1316
1317 hash = vsid ^ (offset / psize);
1318 } else {
1319 unsigned long offset, vsid;
1320
1321 /* We only have 40 - 23 bits of seg_off in avpn */
1322 offset = (avpn & 0x1ffff) << 23;
1323 vsid = avpn >> 17;
1324 if (psize < (1ULL << 23))
1325 offset |= ((vsid ^ (vsid << 25) ^ pteg) & old_hash_mask) * psize;
1326
1327 hash = vsid ^ (vsid << 25) ^ (offset / psize);
1328 }
1329
1330 new_pteg = hash & new_hash_mask;
1331 if (vpte & HPTE_V_SECONDARY) {
1332 BUG_ON(~pteg != (hash & old_hash_mask));
1333 new_pteg = ~new_pteg;
1334 } else {
1335 BUG_ON(pteg != (hash & old_hash_mask));
1336 }
1337
1338 new_idx = new_pteg * HPTES_PER_GROUP + (idx % HPTES_PER_GROUP);
1339 new_hptep = (__be64 *)(new->virt + (new_idx << 4));
1340
1341 replace_vpte = be64_to_cpu(new_hptep[0]);
1342
1343 if (replace_vpte & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1344 BUG_ON(new->order >= old->order);
1345
1346 if (replace_vpte & HPTE_V_BOLTED) {
1347 if (vpte & HPTE_V_BOLTED)
1348 /* Bolted collision, nothing we can do */
1349 ret = -ENOSPC;
1350 /* Discard the new HPTE */
1351 goto out;
1352 }
1353
1354 /* Discard the previous HPTE */
1355 }
1356
1357 new_hptep[1] = cpu_to_be64(rpte);
1358 new->rev[new_idx].guest_rpte = guest_rpte;
1359 /* No need for a barrier, since new HPT isn't active */
1360 new_hptep[0] = cpu_to_be64(vpte);
1361 unlock_hpte(new_hptep, vpte);
1362
1363 out:
1364 unlock_hpte(hptep, vpte);
1365 return ret;
1366 }
1367
1368 static int resize_hpt_rehash(struct kvm_resize_hpt *resize)
1369 {
1370 struct kvm *kvm = resize->kvm;
1371 unsigned long i;
1372 int rc;
1373
1374 /*
1375 * resize_hpt_rehash_hpte() doesn't handle the new-format HPTEs
1376 * that POWER9 uses, and could well hit a BUG_ON on POWER9.
1377 */
1378 if (cpu_has_feature(CPU_FTR_ARCH_300))
1379 return -EIO;
1380 for (i = 0; i < kvmppc_hpt_npte(&kvm->arch.hpt); i++) {
1381 rc = resize_hpt_rehash_hpte(resize, i);
1382 if (rc != 0)
1383 return rc;
1384 }
1385
1386 return 0;
1387 }
1388
1389 static void resize_hpt_pivot(struct kvm_resize_hpt *resize)
1390 {
1391 struct kvm *kvm = resize->kvm;
1392 struct kvm_hpt_info hpt_tmp;
1393
1394 /* Exchange the pending tables in the resize structure with
1395 * the active tables */
1396
1397 resize_hpt_debug(resize, "resize_hpt_pivot()\n");
1398
1399 spin_lock(&kvm->mmu_lock);
1400 asm volatile("ptesync" : : : "memory");
1401
1402 hpt_tmp = kvm->arch.hpt;
1403 kvmppc_set_hpt(kvm, &resize->hpt);
1404 resize->hpt = hpt_tmp;
1405
1406 spin_unlock(&kvm->mmu_lock);
1407
1408 synchronize_srcu_expedited(&kvm->srcu);
1409
1410 resize_hpt_debug(resize, "resize_hpt_pivot() done\n");
1411 }
1412
1413 static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize)
1414 {
1415 BUG_ON(kvm->arch.resize_hpt != resize);
1416
1417 if (!resize)
1418 return;
1419
1420 if (resize->hpt.virt)
1421 kvmppc_free_hpt(&resize->hpt);
1422
1423 kvm->arch.resize_hpt = NULL;
1424 kfree(resize);
1425 }
1426
1427 static void resize_hpt_prepare_work(struct work_struct *work)
1428 {
1429 struct kvm_resize_hpt *resize = container_of(work,
1430 struct kvm_resize_hpt,
1431 work);
1432 struct kvm *kvm = resize->kvm;
1433 int err;
1434
1435 resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n",
1436 resize->order);
1437
1438 err = resize_hpt_allocate(resize);
1439
1440 mutex_lock(&kvm->lock);
1441
1442 resize->error = err;
1443 resize->prepare_done = true;
1444
1445 mutex_unlock(&kvm->lock);
1446 }
1447
1448 long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
1449 struct kvm_ppc_resize_hpt *rhpt)
1450 {
1451 unsigned long flags = rhpt->flags;
1452 unsigned long shift = rhpt->shift;
1453 struct kvm_resize_hpt *resize;
1454 int ret;
1455
1456 if (flags != 0 || kvm_is_radix(kvm))
1457 return -EINVAL;
1458
1459 if (shift && ((shift < 18) || (shift > 46)))
1460 return -EINVAL;
1461
1462 mutex_lock(&kvm->lock);
1463
1464 resize = kvm->arch.resize_hpt;
1465
1466 if (resize) {
1467 if (resize->order == shift) {
1468 /* Suitable resize in progress */
1469 if (resize->prepare_done) {
1470 ret = resize->error;
1471 if (ret != 0)
1472 resize_hpt_release(kvm, resize);
1473 } else {
1474 ret = 100; /* estimated time in ms */
1475 }
1476
1477 goto out;
1478 }
1479
1480 /* not suitable, cancel it */
1481 resize_hpt_release(kvm, resize);
1482 }
1483
1484 ret = 0;
1485 if (!shift)
1486 goto out; /* nothing to do */
1487
1488 /* start new resize */
1489
1490 resize = kzalloc(sizeof(*resize), GFP_KERNEL);
1491 if (!resize) {
1492 ret = -ENOMEM;
1493 goto out;
1494 }
1495 resize->order = shift;
1496 resize->kvm = kvm;
1497 INIT_WORK(&resize->work, resize_hpt_prepare_work);
1498 kvm->arch.resize_hpt = resize;
1499
1500 schedule_work(&resize->work);
1501
1502 ret = 100; /* estimated time in ms */
1503
1504 out:
1505 mutex_unlock(&kvm->lock);
1506 return ret;
1507 }
1508
1509 static void resize_hpt_boot_vcpu(void *opaque)
1510 {
1511 /* Nothing to do, just force a KVM exit */
1512 }
1513
1514 long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
1515 struct kvm_ppc_resize_hpt *rhpt)
1516 {
1517 unsigned long flags = rhpt->flags;
1518 unsigned long shift = rhpt->shift;
1519 struct kvm_resize_hpt *resize;
1520 long ret;
1521
1522 if (flags != 0 || kvm_is_radix(kvm))
1523 return -EINVAL;
1524
1525 if (shift && ((shift < 18) || (shift > 46)))
1526 return -EINVAL;
1527
1528 mutex_lock(&kvm->lock);
1529
1530 resize = kvm->arch.resize_hpt;
1531
1532 /* This shouldn't be possible */
1533 ret = -EIO;
1534 if (WARN_ON(!kvm->arch.mmu_ready))
1535 goto out_no_hpt;
1536
1537 /* Stop VCPUs from running while we mess with the HPT */
1538 kvm->arch.mmu_ready = 0;
1539 smp_mb();
1540
1541 /* Boot all CPUs out of the guest so they re-read
1542 * mmu_ready */
1543 on_each_cpu(resize_hpt_boot_vcpu, NULL, 1);
1544
1545 ret = -ENXIO;
1546 if (!resize || (resize->order != shift))
1547 goto out;
1548
1549 ret = -EBUSY;
1550 if (!resize->prepare_done)
1551 goto out;
1552
1553 ret = resize->error;
1554 if (ret != 0)
1555 goto out;
1556
1557 ret = resize_hpt_rehash(resize);
1558 if (ret != 0)
1559 goto out;
1560
1561 resize_hpt_pivot(resize);
1562
1563 out:
1564 /* Let VCPUs run again */
1565 kvm->arch.mmu_ready = 1;
1566 smp_mb();
1567 out_no_hpt:
1568 resize_hpt_release(kvm, resize);
1569 mutex_unlock(&kvm->lock);
1570 return ret;
1571 }
1572
1573 /*
1574 * Functions for reading and writing the hash table via reads and
1575 * writes on a file descriptor.
1576 *
1577 * Reads return the guest view of the hash table, which has to be
1578 * pieced together from the real hash table and the guest_rpte
1579 * values in the revmap array.
1580 *
1581 * On writes, each HPTE written is considered in turn, and if it
1582 * is valid, it is written to the HPT as if an H_ENTER with the
1583 * exact flag set was done. When the invalid count is non-zero
1584 * in the header written to the stream, the kernel will make
1585 * sure that that many HPTEs are invalid, and invalidate them
1586 * if not.
1587 */
1588
1589 struct kvm_htab_ctx {
1590 unsigned long index;
1591 unsigned long flags;
1592 struct kvm *kvm;
1593 int first_pass;
1594 };
1595
1596 #define HPTE_SIZE (2 * sizeof(unsigned long))
1597
1598 /*
1599 * Returns 1 if this HPT entry has been modified or has pending
1600 * R/C bit changes.
1601 */
1602 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp)
1603 {
1604 unsigned long rcbits_unset;
1605
1606 if (revp->guest_rpte & HPTE_GR_MODIFIED)
1607 return 1;
1608
1609 /* Also need to consider changes in reference and changed bits */
1610 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1611 if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) &&
1612 (be64_to_cpu(hptp[1]) & rcbits_unset))
1613 return 1;
1614
1615 return 0;
1616 }
1617
1618 static long record_hpte(unsigned long flags, __be64 *hptp,
1619 unsigned long *hpte, struct revmap_entry *revp,
1620 int want_valid, int first_pass)
1621 {
1622 unsigned long v, r, hr;
1623 unsigned long rcbits_unset;
1624 int ok = 1;
1625 int valid, dirty;
1626
1627 /* Unmodified entries are uninteresting except on the first pass */
1628 dirty = hpte_dirty(revp, hptp);
1629 if (!first_pass && !dirty)
1630 return 0;
1631
1632 valid = 0;
1633 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1634 valid = 1;
1635 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1636 !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED))
1637 valid = 0;
1638 }
1639 if (valid != want_valid)
1640 return 0;
1641
1642 v = r = 0;
1643 if (valid || dirty) {
1644 /* lock the HPTE so it's stable and read it */
1645 preempt_disable();
1646 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1647 cpu_relax();
1648 v = be64_to_cpu(hptp[0]);
1649 hr = be64_to_cpu(hptp[1]);
1650 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1651 v = hpte_new_to_old_v(v, hr);
1652 hr = hpte_new_to_old_r(hr);
1653 }
1654
1655 /* re-evaluate valid and dirty from synchronized HPTE value */
1656 valid = !!(v & HPTE_V_VALID);
1657 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1658
1659 /* Harvest R and C into guest view if necessary */
1660 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1661 if (valid && (rcbits_unset & hr)) {
1662 revp->guest_rpte |= (hr &
1663 (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED;
1664 dirty = 1;
1665 }
1666
1667 if (v & HPTE_V_ABSENT) {
1668 v &= ~HPTE_V_ABSENT;
1669 v |= HPTE_V_VALID;
1670 valid = 1;
1671 }
1672 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1673 valid = 0;
1674
1675 r = revp->guest_rpte;
1676 /* only clear modified if this is the right sort of entry */
1677 if (valid == want_valid && dirty) {
1678 r &= ~HPTE_GR_MODIFIED;
1679 revp->guest_rpte = r;
1680 }
1681 unlock_hpte(hptp, be64_to_cpu(hptp[0]));
1682 preempt_enable();
1683 if (!(valid == want_valid && (first_pass || dirty)))
1684 ok = 0;
1685 }
1686 hpte[0] = cpu_to_be64(v);
1687 hpte[1] = cpu_to_be64(r);
1688 return ok;
1689 }
1690
1691 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1692 size_t count, loff_t *ppos)
1693 {
1694 struct kvm_htab_ctx *ctx = file->private_data;
1695 struct kvm *kvm = ctx->kvm;
1696 struct kvm_get_htab_header hdr;
1697 __be64 *hptp;
1698 struct revmap_entry *revp;
1699 unsigned long i, nb, nw;
1700 unsigned long __user *lbuf;
1701 struct kvm_get_htab_header __user *hptr;
1702 unsigned long flags;
1703 int first_pass;
1704 unsigned long hpte[2];
1705
1706 if (!access_ok(VERIFY_WRITE, buf, count))
1707 return -EFAULT;
1708 if (kvm_is_radix(kvm))
1709 return 0;
1710
1711 first_pass = ctx->first_pass;
1712 flags = ctx->flags;
1713
1714 i = ctx->index;
1715 hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1716 revp = kvm->arch.hpt.rev + i;
1717 lbuf = (unsigned long __user *)buf;
1718
1719 nb = 0;
1720 while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1721 /* Initialize header */
1722 hptr = (struct kvm_get_htab_header __user *)buf;
1723 hdr.n_valid = 0;
1724 hdr.n_invalid = 0;
1725 nw = nb;
1726 nb += sizeof(hdr);
1727 lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1728
1729 /* Skip uninteresting entries, i.e. clean on not-first pass */
1730 if (!first_pass) {
1731 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1732 !hpte_dirty(revp, hptp)) {
1733 ++i;
1734 hptp += 2;
1735 ++revp;
1736 }
1737 }
1738 hdr.index = i;
1739
1740 /* Grab a series of valid entries */
1741 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1742 hdr.n_valid < 0xffff &&
1743 nb + HPTE_SIZE < count &&
1744 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1745 /* valid entry, write it out */
1746 ++hdr.n_valid;
1747 if (__put_user(hpte[0], lbuf) ||
1748 __put_user(hpte[1], lbuf + 1))
1749 return -EFAULT;
1750 nb += HPTE_SIZE;
1751 lbuf += 2;
1752 ++i;
1753 hptp += 2;
1754 ++revp;
1755 }
1756 /* Now skip invalid entries while we can */
1757 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1758 hdr.n_invalid < 0xffff &&
1759 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1760 /* found an invalid entry */
1761 ++hdr.n_invalid;
1762 ++i;
1763 hptp += 2;
1764 ++revp;
1765 }
1766
1767 if (hdr.n_valid || hdr.n_invalid) {
1768 /* write back the header */
1769 if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1770 return -EFAULT;
1771 nw = nb;
1772 buf = (char __user *)lbuf;
1773 } else {
1774 nb = nw;
1775 }
1776
1777 /* Check if we've wrapped around the hash table */
1778 if (i >= kvmppc_hpt_npte(&kvm->arch.hpt)) {
1779 i = 0;
1780 ctx->first_pass = 0;
1781 break;
1782 }
1783 }
1784
1785 ctx->index = i;
1786
1787 return nb;
1788 }
1789
1790 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1791 size_t count, loff_t *ppos)
1792 {
1793 struct kvm_htab_ctx *ctx = file->private_data;
1794 struct kvm *kvm = ctx->kvm;
1795 struct kvm_get_htab_header hdr;
1796 unsigned long i, j;
1797 unsigned long v, r;
1798 unsigned long __user *lbuf;
1799 __be64 *hptp;
1800 unsigned long tmp[2];
1801 ssize_t nb;
1802 long int err, ret;
1803 int mmu_ready;
1804
1805 if (!access_ok(VERIFY_READ, buf, count))
1806 return -EFAULT;
1807 if (kvm_is_radix(kvm))
1808 return -EINVAL;
1809
1810 /* lock out vcpus from running while we're doing this */
1811 mutex_lock(&kvm->lock);
1812 mmu_ready = kvm->arch.mmu_ready;
1813 if (mmu_ready) {
1814 kvm->arch.mmu_ready = 0; /* temporarily */
1815 /* order mmu_ready vs. vcpus_running */
1816 smp_mb();
1817 if (atomic_read(&kvm->arch.vcpus_running)) {
1818 kvm->arch.mmu_ready = 1;
1819 mutex_unlock(&kvm->lock);
1820 return -EBUSY;
1821 }
1822 }
1823
1824 err = 0;
1825 for (nb = 0; nb + sizeof(hdr) <= count; ) {
1826 err = -EFAULT;
1827 if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1828 break;
1829
1830 err = 0;
1831 if (nb + hdr.n_valid * HPTE_SIZE > count)
1832 break;
1833
1834 nb += sizeof(hdr);
1835 buf += sizeof(hdr);
1836
1837 err = -EINVAL;
1838 i = hdr.index;
1839 if (i >= kvmppc_hpt_npte(&kvm->arch.hpt) ||
1840 i + hdr.n_valid + hdr.n_invalid > kvmppc_hpt_npte(&kvm->arch.hpt))
1841 break;
1842
1843 hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1844 lbuf = (unsigned long __user *)buf;
1845 for (j = 0; j < hdr.n_valid; ++j) {
1846 __be64 hpte_v;
1847 __be64 hpte_r;
1848
1849 err = -EFAULT;
1850 if (__get_user(hpte_v, lbuf) ||
1851 __get_user(hpte_r, lbuf + 1))
1852 goto out;
1853 v = be64_to_cpu(hpte_v);
1854 r = be64_to_cpu(hpte_r);
1855 err = -EINVAL;
1856 if (!(v & HPTE_V_VALID))
1857 goto out;
1858 lbuf += 2;
1859 nb += HPTE_SIZE;
1860
1861 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1862 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1863 err = -EIO;
1864 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1865 tmp);
1866 if (ret != H_SUCCESS) {
1867 pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
1868 "r=%lx\n", ret, i, v, r);
1869 goto out;
1870 }
1871 if (!mmu_ready && is_vrma_hpte(v)) {
1872 unsigned long psize = hpte_base_page_size(v, r);
1873 unsigned long senc = slb_pgsize_encoding(psize);
1874 unsigned long lpcr;
1875
1876 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1877 (VRMA_VSID << SLB_VSID_SHIFT_1T);
1878 lpcr = senc << (LPCR_VRMASD_SH - 4);
1879 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD);
1880 mmu_ready = 1;
1881 }
1882 ++i;
1883 hptp += 2;
1884 }
1885
1886 for (j = 0; j < hdr.n_invalid; ++j) {
1887 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1888 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1889 ++i;
1890 hptp += 2;
1891 }
1892 err = 0;
1893 }
1894
1895 out:
1896 /* Order HPTE updates vs. mmu_ready */
1897 smp_wmb();
1898 kvm->arch.mmu_ready = mmu_ready;
1899 mutex_unlock(&kvm->lock);
1900
1901 if (err)
1902 return err;
1903 return nb;
1904 }
1905
1906 static int kvm_htab_release(struct inode *inode, struct file *filp)
1907 {
1908 struct kvm_htab_ctx *ctx = filp->private_data;
1909
1910 filp->private_data = NULL;
1911 if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1912 atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1913 kvm_put_kvm(ctx->kvm);
1914 kfree(ctx);
1915 return 0;
1916 }
1917
1918 static const struct file_operations kvm_htab_fops = {
1919 .read = kvm_htab_read,
1920 .write = kvm_htab_write,
1921 .llseek = default_llseek,
1922 .release = kvm_htab_release,
1923 };
1924
1925 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1926 {
1927 int ret;
1928 struct kvm_htab_ctx *ctx;
1929 int rwflag;
1930
1931 /* reject flags we don't recognize */
1932 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1933 return -EINVAL;
1934 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1935 if (!ctx)
1936 return -ENOMEM;
1937 kvm_get_kvm(kvm);
1938 ctx->kvm = kvm;
1939 ctx->index = ghf->start_index;
1940 ctx->flags = ghf->flags;
1941 ctx->first_pass = 1;
1942
1943 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1944 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
1945 if (ret < 0) {
1946 kfree(ctx);
1947 kvm_put_kvm(kvm);
1948 return ret;
1949 }
1950
1951 if (rwflag == O_RDONLY) {
1952 mutex_lock(&kvm->slots_lock);
1953 atomic_inc(&kvm->arch.hpte_mod_interest);
1954 /* make sure kvmppc_do_h_enter etc. see the increment */
1955 synchronize_srcu_expedited(&kvm->srcu);
1956 mutex_unlock(&kvm->slots_lock);
1957 }
1958
1959 return ret;
1960 }
1961
1962 struct debugfs_htab_state {
1963 struct kvm *kvm;
1964 struct mutex mutex;
1965 unsigned long hpt_index;
1966 int chars_left;
1967 int buf_index;
1968 char buf[64];
1969 };
1970
1971 static int debugfs_htab_open(struct inode *inode, struct file *file)
1972 {
1973 struct kvm *kvm = inode->i_private;
1974 struct debugfs_htab_state *p;
1975
1976 p = kzalloc(sizeof(*p), GFP_KERNEL);
1977 if (!p)
1978 return -ENOMEM;
1979
1980 kvm_get_kvm(kvm);
1981 p->kvm = kvm;
1982 mutex_init(&p->mutex);
1983 file->private_data = p;
1984
1985 return nonseekable_open(inode, file);
1986 }
1987
1988 static int debugfs_htab_release(struct inode *inode, struct file *file)
1989 {
1990 struct debugfs_htab_state *p = file->private_data;
1991
1992 kvm_put_kvm(p->kvm);
1993 kfree(p);
1994 return 0;
1995 }
1996
1997 static ssize_t debugfs_htab_read(struct file *file, char __user *buf,
1998 size_t len, loff_t *ppos)
1999 {
2000 struct debugfs_htab_state *p = file->private_data;
2001 ssize_t ret, r;
2002 unsigned long i, n;
2003 unsigned long v, hr, gr;
2004 struct kvm *kvm;
2005 __be64 *hptp;
2006
2007 kvm = p->kvm;
2008 if (kvm_is_radix(kvm))
2009 return 0;
2010
2011 ret = mutex_lock_interruptible(&p->mutex);
2012 if (ret)
2013 return ret;
2014
2015 if (p->chars_left) {
2016 n = p->chars_left;
2017 if (n > len)
2018 n = len;
2019 r = copy_to_user(buf, p->buf + p->buf_index, n);
2020 n -= r;
2021 p->chars_left -= n;
2022 p->buf_index += n;
2023 buf += n;
2024 len -= n;
2025 ret = n;
2026 if (r) {
2027 if (!n)
2028 ret = -EFAULT;
2029 goto out;
2030 }
2031 }
2032
2033 i = p->hpt_index;
2034 hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
2035 for (; len != 0 && i < kvmppc_hpt_npte(&kvm->arch.hpt);
2036 ++i, hptp += 2) {
2037 if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)))
2038 continue;
2039
2040 /* lock the HPTE so it's stable and read it */
2041 preempt_disable();
2042 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
2043 cpu_relax();
2044 v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK;
2045 hr = be64_to_cpu(hptp[1]);
2046 gr = kvm->arch.hpt.rev[i].guest_rpte;
2047 unlock_hpte(hptp, v);
2048 preempt_enable();
2049
2050 if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
2051 continue;
2052
2053 n = scnprintf(p->buf, sizeof(p->buf),
2054 "%6lx %.16lx %.16lx %.16lx\n",
2055 i, v, hr, gr);
2056 p->chars_left = n;
2057 if (n > len)
2058 n = len;
2059 r = copy_to_user(buf, p->buf, n);
2060 n -= r;
2061 p->chars_left -= n;
2062 p->buf_index = n;
2063 buf += n;
2064 len -= n;
2065 ret += n;
2066 if (r) {
2067 if (!ret)
2068 ret = -EFAULT;
2069 goto out;
2070 }
2071 }
2072 p->hpt_index = i;
2073
2074 out:
2075 mutex_unlock(&p->mutex);
2076 return ret;
2077 }
2078
2079 static ssize_t debugfs_htab_write(struct file *file, const char __user *buf,
2080 size_t len, loff_t *ppos)
2081 {
2082 return -EACCES;
2083 }
2084
2085 static const struct file_operations debugfs_htab_fops = {
2086 .owner = THIS_MODULE,
2087 .open = debugfs_htab_open,
2088 .release = debugfs_htab_release,
2089 .read = debugfs_htab_read,
2090 .write = debugfs_htab_write,
2091 .llseek = generic_file_llseek,
2092 };
2093
2094 void kvmppc_mmu_debugfs_init(struct kvm *kvm)
2095 {
2096 kvm->arch.htab_dentry = debugfs_create_file("htab", 0400,
2097 kvm->arch.debugfs_dir, kvm,
2098 &debugfs_htab_fops);
2099 }
2100
2101 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
2102 {
2103 struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
2104
2105 vcpu->arch.slb_nr = 32; /* POWER7/POWER8 */
2106
2107 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
2108 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
2109
2110 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
2111 }
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