Merge tag 'kvm-ppc-next-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[muen/linux.git] / arch / powerpc / kvm / book3s_64_mmu_hv.c
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
69         /* Possible values and their usage:
70          *  <0     an error occurred during allocation,
71          *  -EBUSY allocation is in the progress,
72          *  0      allocation made successfuly.
73          */
74         int error;
75
76         /* Private to the work thread, until error != -EBUSY,
77          * then protected by kvm->lock.
78          */
79         struct kvm_hpt_info hpt;
80 };
81
82 int kvmppc_allocate_hpt(struct kvm_hpt_info *info, u32 order)
83 {
84         unsigned long hpt = 0;
85         int cma = 0;
86         struct page *page = NULL;
87         struct revmap_entry *rev;
88         unsigned long npte;
89
90         if ((order < PPC_MIN_HPT_ORDER) || (order > PPC_MAX_HPT_ORDER))
91                 return -EINVAL;
92
93         page = kvm_alloc_hpt_cma(1ul << (order - PAGE_SHIFT));
94         if (page) {
95                 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
96                 memset((void *)hpt, 0, (1ul << order));
97                 cma = 1;
98         }
99
100         if (!hpt)
101                 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_RETRY_MAYFAIL
102                                        |__GFP_NOWARN, order - PAGE_SHIFT);
103
104         if (!hpt)
105                 return -ENOMEM;
106
107         /* HPTEs are 2**4 bytes long */
108         npte = 1ul << (order - 4);
109
110         /* Allocate reverse map array */
111         rev = vmalloc(sizeof(struct revmap_entry) * npte);
112         if (!rev) {
113                 if (cma)
114                         kvm_free_hpt_cma(page, 1 << (order - PAGE_SHIFT));
115                 else
116                         free_pages(hpt, order - PAGE_SHIFT);
117                 return -ENOMEM;
118         }
119
120         info->order = order;
121         info->virt = hpt;
122         info->cma = cma;
123         info->rev = rev;
124
125         return 0;
126 }
127
128 void kvmppc_set_hpt(struct kvm *kvm, struct kvm_hpt_info *info)
129 {
130         atomic64_set(&kvm->arch.mmio_update, 0);
131         kvm->arch.hpt = *info;
132         kvm->arch.sdr1 = __pa(info->virt) | (info->order - 18);
133
134         pr_debug("KVM guest htab at %lx (order %ld), LPID %x\n",
135                  info->virt, (long)info->order, kvm->arch.lpid);
136 }
137
138 long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
139 {
140         long err = -EBUSY;
141         struct kvm_hpt_info info;
142
143         mutex_lock(&kvm->lock);
144         if (kvm->arch.mmu_ready) {
145                 kvm->arch.mmu_ready = 0;
146                 /* order mmu_ready vs. vcpus_running */
147                 smp_mb();
148                 if (atomic_read(&kvm->arch.vcpus_running)) {
149                         kvm->arch.mmu_ready = 1;
150                         goto out;
151                 }
152         }
153         if (kvm_is_radix(kvm)) {
154                 err = kvmppc_switch_mmu_to_hpt(kvm);
155                 if (err)
156                         goto out;
157         }
158
159         if (kvm->arch.hpt.order == order) {
160                 /* We already have a suitable HPT */
161
162                 /* Set the entire HPT to 0, i.e. invalid HPTEs */
163                 memset((void *)kvm->arch.hpt.virt, 0, 1ul << order);
164                 /*
165                  * Reset all the reverse-mapping chains for all memslots
166                  */
167                 kvmppc_rmap_reset(kvm);
168                 err = 0;
169                 goto out;
170         }
171
172         if (kvm->arch.hpt.virt) {
173                 kvmppc_free_hpt(&kvm->arch.hpt);
174                 kvmppc_rmap_reset(kvm);
175         }
176
177         err = kvmppc_allocate_hpt(&info, order);
178         if (err < 0)
179                 goto out;
180         kvmppc_set_hpt(kvm, &info);
181
182 out:
183         if (err == 0)
184                 /* Ensure that each vcpu will flush its TLB on next entry. */
185                 cpumask_setall(&kvm->arch.need_tlb_flush);
186
187         mutex_unlock(&kvm->lock);
188         return err;
189 }
190
191 void kvmppc_free_hpt(struct kvm_hpt_info *info)
192 {
193         vfree(info->rev);
194         info->rev = NULL;
195         if (info->cma)
196                 kvm_free_hpt_cma(virt_to_page(info->virt),
197                                  1 << (info->order - PAGE_SHIFT));
198         else if (info->virt)
199                 free_pages(info->virt, info->order - PAGE_SHIFT);
200         info->virt = 0;
201         info->order = 0;
202 }
203
204 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
205 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
206 {
207         return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
208 }
209
210 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
211 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
212 {
213         return (pgsize == 0x10000) ? 0x1000 : 0;
214 }
215
216 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
217                      unsigned long porder)
218 {
219         unsigned long i;
220         unsigned long npages;
221         unsigned long hp_v, hp_r;
222         unsigned long addr, hash;
223         unsigned long psize;
224         unsigned long hp0, hp1;
225         unsigned long idx_ret;
226         long ret;
227         struct kvm *kvm = vcpu->kvm;
228
229         psize = 1ul << porder;
230         npages = memslot->npages >> (porder - PAGE_SHIFT);
231
232         /* VRMA can't be > 1TB */
233         if (npages > 1ul << (40 - porder))
234                 npages = 1ul << (40 - porder);
235         /* Can't use more than 1 HPTE per HPTEG */
236         if (npages > kvmppc_hpt_mask(&kvm->arch.hpt) + 1)
237                 npages = kvmppc_hpt_mask(&kvm->arch.hpt) + 1;
238
239         hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
240                 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
241         hp1 = hpte1_pgsize_encoding(psize) |
242                 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
243
244         for (i = 0; i < npages; ++i) {
245                 addr = i << porder;
246                 /* can't use hpt_hash since va > 64 bits */
247                 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25)))
248                         & kvmppc_hpt_mask(&kvm->arch.hpt);
249                 /*
250                  * We assume that the hash table is empty and no
251                  * vcpus are using it at this stage.  Since we create
252                  * at most one HPTE per HPTEG, we just assume entry 7
253                  * is available and use it.
254                  */
255                 hash = (hash << 3) + 7;
256                 hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
257                 hp_r = hp1 | addr;
258                 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
259                                                  &idx_ret);
260                 if (ret != H_SUCCESS) {
261                         pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
262                                addr, ret);
263                         break;
264                 }
265         }
266 }
267
268 int kvmppc_mmu_hv_init(void)
269 {
270         unsigned long host_lpid, rsvd_lpid;
271
272         if (!cpu_has_feature(CPU_FTR_HVMODE))
273                 return -EINVAL;
274
275         /* POWER7 has 10-bit LPIDs (12-bit in POWER8) */
276         host_lpid = mfspr(SPRN_LPID);
277         rsvd_lpid = LPID_RSVD;
278
279         kvmppc_init_lpid(rsvd_lpid + 1);
280
281         kvmppc_claim_lpid(host_lpid);
282         /* rsvd_lpid is reserved for use in partition switching */
283         kvmppc_claim_lpid(rsvd_lpid);
284
285         return 0;
286 }
287
288 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
289 {
290         unsigned long msr = vcpu->arch.intr_msr;
291
292         /* If transactional, change to suspend mode on IRQ delivery */
293         if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
294                 msr |= MSR_TS_S;
295         else
296                 msr |= vcpu->arch.shregs.msr & MSR_TS_MASK;
297         kvmppc_set_msr(vcpu, msr);
298 }
299
300 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
301                                 long pte_index, unsigned long pteh,
302                                 unsigned long ptel, unsigned long *pte_idx_ret)
303 {
304         long ret;
305
306         /* Protect linux PTE lookup from page table destruction */
307         rcu_read_lock_sched();  /* this disables preemption too */
308         ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
309                                 current->mm->pgd, false, pte_idx_ret);
310         rcu_read_unlock_sched();
311         if (ret == H_TOO_HARD) {
312                 /* this can't happen */
313                 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
314                 ret = H_RESOURCE;       /* or something */
315         }
316         return ret;
317
318 }
319
320 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
321                                                          gva_t eaddr)
322 {
323         u64 mask;
324         int i;
325
326         for (i = 0; i < vcpu->arch.slb_nr; i++) {
327                 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
328                         continue;
329
330                 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
331                         mask = ESID_MASK_1T;
332                 else
333                         mask = ESID_MASK;
334
335                 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
336                         return &vcpu->arch.slb[i];
337         }
338         return NULL;
339 }
340
341 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
342                         unsigned long ea)
343 {
344         unsigned long ra_mask;
345
346         ra_mask = kvmppc_actual_pgsz(v, r) - 1;
347         return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
348 }
349
350 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
351                         struct kvmppc_pte *gpte, bool data, bool iswrite)
352 {
353         struct kvm *kvm = vcpu->kvm;
354         struct kvmppc_slb *slbe;
355         unsigned long slb_v;
356         unsigned long pp, key;
357         unsigned long v, orig_v, gr;
358         __be64 *hptep;
359         int index;
360         int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
361
362         if (kvm_is_radix(vcpu->kvm))
363                 return kvmppc_mmu_radix_xlate(vcpu, eaddr, gpte, data, iswrite);
364
365         /* Get SLB entry */
366         if (virtmode) {
367                 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
368                 if (!slbe)
369                         return -EINVAL;
370                 slb_v = slbe->origv;
371         } else {
372                 /* real mode access */
373                 slb_v = vcpu->kvm->arch.vrma_slb_v;
374         }
375
376         preempt_disable();
377         /* Find the HPTE in the hash table */
378         index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
379                                          HPTE_V_VALID | HPTE_V_ABSENT);
380         if (index < 0) {
381                 preempt_enable();
382                 return -ENOENT;
383         }
384         hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
385         v = orig_v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
386         if (cpu_has_feature(CPU_FTR_ARCH_300))
387                 v = hpte_new_to_old_v(v, be64_to_cpu(hptep[1]));
388         gr = kvm->arch.hpt.rev[index].guest_rpte;
389
390         unlock_hpte(hptep, orig_v);
391         preempt_enable();
392
393         gpte->eaddr = eaddr;
394         gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
395
396         /* Get PP bits and key for permission check */
397         pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
398         key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
399         key &= slb_v;
400
401         /* Calculate permissions */
402         gpte->may_read = hpte_read_permission(pp, key);
403         gpte->may_write = hpte_write_permission(pp, key);
404         gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
405
406         /* Storage key permission check for POWER7 */
407         if (data && virtmode) {
408                 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
409                 if (amrfield & 1)
410                         gpte->may_read = 0;
411                 if (amrfield & 2)
412                         gpte->may_write = 0;
413         }
414
415         /* Get the guest physical address */
416         gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
417         return 0;
418 }
419
420 /*
421  * Quick test for whether an instruction is a load or a store.
422  * If the instruction is a load or a store, then this will indicate
423  * which it is, at least on server processors.  (Embedded processors
424  * have some external PID instructions that don't follow the rule
425  * embodied here.)  If the instruction isn't a load or store, then
426  * this doesn't return anything useful.
427  */
428 static int instruction_is_store(unsigned int instr)
429 {
430         unsigned int mask;
431
432         mask = 0x10000000;
433         if ((instr & 0xfc000000) == 0x7c000000)
434                 mask = 0x100;           /* major opcode 31 */
435         return (instr & mask) != 0;
436 }
437
438 int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
439                            unsigned long gpa, gva_t ea, int is_store)
440 {
441         u32 last_inst;
442
443         /*
444          * If we fail, we just return to the guest and try executing it again.
445          */
446         if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
447                 EMULATE_DONE)
448                 return RESUME_GUEST;
449
450         /*
451          * WARNING: We do not know for sure whether the instruction we just
452          * read from memory is the same that caused the fault in the first
453          * place.  If the instruction we read is neither an load or a store,
454          * then it can't access memory, so we don't need to worry about
455          * enforcing access permissions.  So, assuming it is a load or
456          * store, we just check that its direction (load or store) is
457          * consistent with the original fault, since that's what we
458          * checked the access permissions against.  If there is a mismatch
459          * we just return and retry the instruction.
460          */
461
462         if (instruction_is_store(last_inst) != !!is_store)
463                 return RESUME_GUEST;
464
465         /*
466          * Emulated accesses are emulated by looking at the hash for
467          * translation once, then performing the access later. The
468          * translation could be invalidated in the meantime in which
469          * point performing the subsequent memory access on the old
470          * physical address could possibly be a security hole for the
471          * guest (but not the host).
472          *
473          * This is less of an issue for MMIO stores since they aren't
474          * globally visible. It could be an issue for MMIO loads to
475          * a certain extent but we'll ignore it for now.
476          */
477
478         vcpu->arch.paddr_accessed = gpa;
479         vcpu->arch.vaddr_accessed = ea;
480         return kvmppc_emulate_mmio(run, vcpu);
481 }
482
483 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
484                                 unsigned long ea, unsigned long dsisr)
485 {
486         struct kvm *kvm = vcpu->kvm;
487         unsigned long hpte[3], r;
488         unsigned long hnow_v, hnow_r;
489         __be64 *hptep;
490         unsigned long mmu_seq, psize, pte_size;
491         unsigned long gpa_base, gfn_base;
492         unsigned long gpa, gfn, hva, pfn;
493         struct kvm_memory_slot *memslot;
494         unsigned long *rmap;
495         struct revmap_entry *rev;
496         struct page *page, *pages[1];
497         long index, ret, npages;
498         bool is_ci;
499         unsigned int writing, write_ok;
500         struct vm_area_struct *vma;
501         unsigned long rcbits;
502         long mmio_update;
503
504         if (kvm_is_radix(kvm))
505                 return kvmppc_book3s_radix_page_fault(run, vcpu, ea, dsisr);
506
507         /*
508          * Real-mode code has already searched the HPT and found the
509          * entry we're interested in.  Lock the entry and check that
510          * it hasn't changed.  If it has, just return and re-execute the
511          * instruction.
512          */
513         if (ea != vcpu->arch.pgfault_addr)
514                 return RESUME_GUEST;
515
516         if (vcpu->arch.pgfault_cache) {
517                 mmio_update = atomic64_read(&kvm->arch.mmio_update);
518                 if (mmio_update == vcpu->arch.pgfault_cache->mmio_update) {
519                         r = vcpu->arch.pgfault_cache->rpte;
520                         psize = kvmppc_actual_pgsz(vcpu->arch.pgfault_hpte[0],
521                                                    r);
522                         gpa_base = r & HPTE_R_RPN & ~(psize - 1);
523                         gfn_base = gpa_base >> PAGE_SHIFT;
524                         gpa = gpa_base | (ea & (psize - 1));
525                         return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
526                                                 dsisr & DSISR_ISSTORE);
527                 }
528         }
529         index = vcpu->arch.pgfault_index;
530         hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
531         rev = &kvm->arch.hpt.rev[index];
532         preempt_disable();
533         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
534                 cpu_relax();
535         hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
536         hpte[1] = be64_to_cpu(hptep[1]);
537         hpte[2] = r = rev->guest_rpte;
538         unlock_hpte(hptep, hpte[0]);
539         preempt_enable();
540
541         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
542                 hpte[0] = hpte_new_to_old_v(hpte[0], hpte[1]);
543                 hpte[1] = hpte_new_to_old_r(hpte[1]);
544         }
545         if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
546             hpte[1] != vcpu->arch.pgfault_hpte[1])
547                 return RESUME_GUEST;
548
549         /* Translate the logical address and get the page */
550         psize = kvmppc_actual_pgsz(hpte[0], r);
551         gpa_base = r & HPTE_R_RPN & ~(psize - 1);
552         gfn_base = gpa_base >> PAGE_SHIFT;
553         gpa = gpa_base | (ea & (psize - 1));
554         gfn = gpa >> PAGE_SHIFT;
555         memslot = gfn_to_memslot(kvm, gfn);
556
557         trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr);
558
559         /* No memslot means it's an emulated MMIO region */
560         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
561                 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
562                                               dsisr & DSISR_ISSTORE);
563
564         /*
565          * This should never happen, because of the slot_is_aligned()
566          * check in kvmppc_do_h_enter().
567          */
568         if (gfn_base < memslot->base_gfn)
569                 return -EFAULT;
570
571         /* used to check for invalidations in progress */
572         mmu_seq = kvm->mmu_notifier_seq;
573         smp_rmb();
574
575         ret = -EFAULT;
576         is_ci = false;
577         pfn = 0;
578         page = NULL;
579         pte_size = PAGE_SIZE;
580         writing = (dsisr & DSISR_ISSTORE) != 0;
581         /* If writing != 0, then the HPTE must allow writing, if we get here */
582         write_ok = writing;
583         hva = gfn_to_hva_memslot(memslot, gfn);
584         npages = get_user_pages_fast(hva, 1, writing, pages);
585         if (npages < 1) {
586                 /* Check if it's an I/O mapping */
587                 down_read(&current->mm->mmap_sem);
588                 vma = find_vma(current->mm, hva);
589                 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
590                     (vma->vm_flags & VM_PFNMAP)) {
591                         pfn = vma->vm_pgoff +
592                                 ((hva - vma->vm_start) >> PAGE_SHIFT);
593                         pte_size = psize;
594                         is_ci = pte_ci(__pte((pgprot_val(vma->vm_page_prot))));
595                         write_ok = vma->vm_flags & VM_WRITE;
596                 }
597                 up_read(&current->mm->mmap_sem);
598                 if (!pfn)
599                         goto out_put;
600         } else {
601                 page = pages[0];
602                 pfn = page_to_pfn(page);
603                 if (PageHuge(page)) {
604                         page = compound_head(page);
605                         pte_size <<= compound_order(page);
606                 }
607                 /* if the guest wants write access, see if that is OK */
608                 if (!writing && hpte_is_writable(r)) {
609                         pte_t *ptep, pte;
610                         unsigned long flags;
611                         /*
612                          * We need to protect against page table destruction
613                          * hugepage split and collapse.
614                          */
615                         local_irq_save(flags);
616                         ptep = find_current_mm_pte(current->mm->pgd,
617                                                    hva, NULL, NULL);
618                         if (ptep) {
619                                 pte = kvmppc_read_update_linux_pte(ptep, 1);
620                                 if (__pte_write(pte))
621                                         write_ok = 1;
622                         }
623                         local_irq_restore(flags);
624                 }
625         }
626
627         if (psize > pte_size)
628                 goto out_put;
629
630         /* Check WIMG vs. the actual page we're accessing */
631         if (!hpte_cache_flags_ok(r, is_ci)) {
632                 if (is_ci)
633                         goto out_put;
634                 /*
635                  * Allow guest to map emulated device memory as
636                  * uncacheable, but actually make it cacheable.
637                  */
638                 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
639         }
640
641         /*
642          * Set the HPTE to point to pfn.
643          * Since the pfn is at PAGE_SIZE granularity, make sure we
644          * don't mask out lower-order bits if psize < PAGE_SIZE.
645          */
646         if (psize < PAGE_SIZE)
647                 psize = PAGE_SIZE;
648         r = (r & HPTE_R_KEY_HI) | (r & ~(HPTE_R_PP0 - psize)) |
649                                         ((pfn << PAGE_SHIFT) & ~(psize - 1));
650         if (hpte_is_writable(r) && !write_ok)
651                 r = hpte_make_readonly(r);
652         ret = RESUME_GUEST;
653         preempt_disable();
654         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
655                 cpu_relax();
656         hnow_v = be64_to_cpu(hptep[0]);
657         hnow_r = be64_to_cpu(hptep[1]);
658         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
659                 hnow_v = hpte_new_to_old_v(hnow_v, hnow_r);
660                 hnow_r = hpte_new_to_old_r(hnow_r);
661         }
662
663         /*
664          * If the HPT is being resized, don't update the HPTE,
665          * instead let the guest retry after the resize operation is complete.
666          * The synchronization for mmu_ready test vs. set is provided
667          * by the HPTE lock.
668          */
669         if (!kvm->arch.mmu_ready)
670                 goto out_unlock;
671
672         if ((hnow_v & ~HPTE_V_HVLOCK) != hpte[0] || hnow_r != hpte[1] ||
673             rev->guest_rpte != hpte[2])
674                 /* HPTE has been changed under us; let the guest retry */
675                 goto out_unlock;
676         hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
677
678         /* Always put the HPTE in the rmap chain for the page base address */
679         rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn];
680         lock_rmap(rmap);
681
682         /* Check if we might have been invalidated; let the guest retry if so */
683         ret = RESUME_GUEST;
684         if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
685                 unlock_rmap(rmap);
686                 goto out_unlock;
687         }
688
689         /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
690         rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
691         r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
692
693         if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) {
694                 /* HPTE was previously valid, so we need to invalidate it */
695                 unlock_rmap(rmap);
696                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
697                 kvmppc_invalidate_hpte(kvm, hptep, index);
698                 /* don't lose previous R and C bits */
699                 r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
700         } else {
701                 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
702         }
703
704         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
705                 r = hpte_old_to_new_r(hpte[0], r);
706                 hpte[0] = hpte_old_to_new_v(hpte[0]);
707         }
708         hptep[1] = cpu_to_be64(r);
709         eieio();
710         __unlock_hpte(hptep, hpte[0]);
711         asm volatile("ptesync" : : : "memory");
712         preempt_enable();
713         if (page && hpte_is_writable(r))
714                 SetPageDirty(page);
715
716  out_put:
717         trace_kvm_page_fault_exit(vcpu, hpte, ret);
718
719         if (page) {
720                 /*
721                  * We drop pages[0] here, not page because page might
722                  * have been set to the head page of a compound, but
723                  * we have to drop the reference on the correct tail
724                  * page to match the get inside gup()
725                  */
726                 put_page(pages[0]);
727         }
728         return ret;
729
730  out_unlock:
731         __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
732         preempt_enable();
733         goto out_put;
734 }
735
736 void kvmppc_rmap_reset(struct kvm *kvm)
737 {
738         struct kvm_memslots *slots;
739         struct kvm_memory_slot *memslot;
740         int srcu_idx;
741
742         srcu_idx = srcu_read_lock(&kvm->srcu);
743         slots = kvm_memslots(kvm);
744         kvm_for_each_memslot(memslot, slots) {
745                 /*
746                  * This assumes it is acceptable to lose reference and
747                  * change bits across a reset.
748                  */
749                 memset(memslot->arch.rmap, 0,
750                        memslot->npages * sizeof(*memslot->arch.rmap));
751         }
752         srcu_read_unlock(&kvm->srcu, srcu_idx);
753 }
754
755 typedef int (*hva_handler_fn)(struct kvm *kvm, struct kvm_memory_slot *memslot,
756                               unsigned long gfn);
757
758 static int kvm_handle_hva_range(struct kvm *kvm,
759                                 unsigned long start,
760                                 unsigned long end,
761                                 hva_handler_fn handler)
762 {
763         int ret;
764         int retval = 0;
765         struct kvm_memslots *slots;
766         struct kvm_memory_slot *memslot;
767
768         slots = kvm_memslots(kvm);
769         kvm_for_each_memslot(memslot, slots) {
770                 unsigned long hva_start, hva_end;
771                 gfn_t gfn, gfn_end;
772
773                 hva_start = max(start, memslot->userspace_addr);
774                 hva_end = min(end, memslot->userspace_addr +
775                                         (memslot->npages << PAGE_SHIFT));
776                 if (hva_start >= hva_end)
777                         continue;
778                 /*
779                  * {gfn(page) | page intersects with [hva_start, hva_end)} =
780                  * {gfn, gfn+1, ..., gfn_end-1}.
781                  */
782                 gfn = hva_to_gfn_memslot(hva_start, memslot);
783                 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
784
785                 for (; gfn < gfn_end; ++gfn) {
786                         ret = handler(kvm, memslot, gfn);
787                         retval |= ret;
788                 }
789         }
790
791         return retval;
792 }
793
794 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
795                           hva_handler_fn handler)
796 {
797         return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
798 }
799
800 /* Must be called with both HPTE and rmap locked */
801 static void kvmppc_unmap_hpte(struct kvm *kvm, unsigned long i,
802                               struct kvm_memory_slot *memslot,
803                               unsigned long *rmapp, unsigned long gfn)
804 {
805         __be64 *hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
806         struct revmap_entry *rev = kvm->arch.hpt.rev;
807         unsigned long j, h;
808         unsigned long ptel, psize, rcbits;
809
810         j = rev[i].forw;
811         if (j == i) {
812                 /* chain is now empty */
813                 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
814         } else {
815                 /* remove i from chain */
816                 h = rev[i].back;
817                 rev[h].forw = j;
818                 rev[j].back = h;
819                 rev[i].forw = rev[i].back = i;
820                 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
821         }
822
823         /* Now check and modify the HPTE */
824         ptel = rev[i].guest_rpte;
825         psize = kvmppc_actual_pgsz(be64_to_cpu(hptep[0]), ptel);
826         if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
827             hpte_rpn(ptel, psize) == gfn) {
828                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
829                 kvmppc_invalidate_hpte(kvm, hptep, i);
830                 hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
831                 /* Harvest R and C */
832                 rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
833                 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
834                 if ((rcbits & HPTE_R_C) && memslot->dirty_bitmap)
835                         kvmppc_update_dirty_map(memslot, gfn, psize);
836                 if (rcbits & ~rev[i].guest_rpte) {
837                         rev[i].guest_rpte = ptel | rcbits;
838                         note_hpte_modification(kvm, &rev[i]);
839                 }
840         }
841 }
842
843 static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
844                            unsigned long gfn)
845 {
846         unsigned long i;
847         __be64 *hptep;
848         unsigned long *rmapp;
849
850         rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
851         for (;;) {
852                 lock_rmap(rmapp);
853                 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
854                         unlock_rmap(rmapp);
855                         break;
856                 }
857
858                 /*
859                  * To avoid an ABBA deadlock with the HPTE lock bit,
860                  * we can't spin on the HPTE lock while holding the
861                  * rmap chain lock.
862                  */
863                 i = *rmapp & KVMPPC_RMAP_INDEX;
864                 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
865                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
866                         /* unlock rmap before spinning on the HPTE lock */
867                         unlock_rmap(rmapp);
868                         while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
869                                 cpu_relax();
870                         continue;
871                 }
872
873                 kvmppc_unmap_hpte(kvm, i, memslot, rmapp, gfn);
874                 unlock_rmap(rmapp);
875                 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
876         }
877         return 0;
878 }
879
880 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva)
881 {
882         hva_handler_fn handler;
883
884         handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
885         kvm_handle_hva(kvm, hva, handler);
886         return 0;
887 }
888
889 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end)
890 {
891         hva_handler_fn handler;
892
893         handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
894         kvm_handle_hva_range(kvm, start, end, handler);
895         return 0;
896 }
897
898 void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
899                                   struct kvm_memory_slot *memslot)
900 {
901         unsigned long gfn;
902         unsigned long n;
903         unsigned long *rmapp;
904
905         gfn = memslot->base_gfn;
906         rmapp = memslot->arch.rmap;
907         for (n = memslot->npages; n; --n, ++gfn) {
908                 if (kvm_is_radix(kvm)) {
909                         kvm_unmap_radix(kvm, memslot, gfn);
910                         continue;
911                 }
912                 /*
913                  * Testing the present bit without locking is OK because
914                  * the memslot has been marked invalid already, and hence
915                  * no new HPTEs referencing this page can be created,
916                  * thus the present bit can't go from 0 to 1.
917                  */
918                 if (*rmapp & KVMPPC_RMAP_PRESENT)
919                         kvm_unmap_rmapp(kvm, memslot, gfn);
920                 ++rmapp;
921         }
922 }
923
924 static int kvm_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
925                          unsigned long gfn)
926 {
927         struct revmap_entry *rev = kvm->arch.hpt.rev;
928         unsigned long head, i, j;
929         __be64 *hptep;
930         int ret = 0;
931         unsigned long *rmapp;
932
933         rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
934  retry:
935         lock_rmap(rmapp);
936         if (*rmapp & KVMPPC_RMAP_REFERENCED) {
937                 *rmapp &= ~KVMPPC_RMAP_REFERENCED;
938                 ret = 1;
939         }
940         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
941                 unlock_rmap(rmapp);
942                 return ret;
943         }
944
945         i = head = *rmapp & KVMPPC_RMAP_INDEX;
946         do {
947                 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
948                 j = rev[i].forw;
949
950                 /* If this HPTE isn't referenced, ignore it */
951                 if (!(be64_to_cpu(hptep[1]) & HPTE_R_R))
952                         continue;
953
954                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
955                         /* unlock rmap before spinning on the HPTE lock */
956                         unlock_rmap(rmapp);
957                         while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
958                                 cpu_relax();
959                         goto retry;
960                 }
961
962                 /* Now check and modify the HPTE */
963                 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
964                     (be64_to_cpu(hptep[1]) & HPTE_R_R)) {
965                         kvmppc_clear_ref_hpte(kvm, hptep, i);
966                         if (!(rev[i].guest_rpte & HPTE_R_R)) {
967                                 rev[i].guest_rpte |= HPTE_R_R;
968                                 note_hpte_modification(kvm, &rev[i]);
969                         }
970                         ret = 1;
971                 }
972                 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
973         } while ((i = j) != head);
974
975         unlock_rmap(rmapp);
976         return ret;
977 }
978
979 int kvm_age_hva_hv(struct kvm *kvm, unsigned long start, unsigned long end)
980 {
981         hva_handler_fn handler;
982
983         handler = kvm_is_radix(kvm) ? kvm_age_radix : kvm_age_rmapp;
984         return kvm_handle_hva_range(kvm, start, end, handler);
985 }
986
987 static int kvm_test_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
988                               unsigned long gfn)
989 {
990         struct revmap_entry *rev = kvm->arch.hpt.rev;
991         unsigned long head, i, j;
992         unsigned long *hp;
993         int ret = 1;
994         unsigned long *rmapp;
995
996         rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
997         if (*rmapp & KVMPPC_RMAP_REFERENCED)
998                 return 1;
999
1000         lock_rmap(rmapp);
1001         if (*rmapp & KVMPPC_RMAP_REFERENCED)
1002                 goto out;
1003
1004         if (*rmapp & KVMPPC_RMAP_PRESENT) {
1005                 i = head = *rmapp & KVMPPC_RMAP_INDEX;
1006                 do {
1007                         hp = (unsigned long *)(kvm->arch.hpt.virt + (i << 4));
1008                         j = rev[i].forw;
1009                         if (be64_to_cpu(hp[1]) & HPTE_R_R)
1010                                 goto out;
1011                 } while ((i = j) != head);
1012         }
1013         ret = 0;
1014
1015  out:
1016         unlock_rmap(rmapp);
1017         return ret;
1018 }
1019
1020 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva)
1021 {
1022         hva_handler_fn handler;
1023
1024         handler = kvm_is_radix(kvm) ? kvm_test_age_radix : kvm_test_age_rmapp;
1025         return kvm_handle_hva(kvm, hva, handler);
1026 }
1027
1028 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte)
1029 {
1030         hva_handler_fn handler;
1031
1032         handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
1033         kvm_handle_hva(kvm, hva, handler);
1034 }
1035
1036 static int vcpus_running(struct kvm *kvm)
1037 {
1038         return atomic_read(&kvm->arch.vcpus_running) != 0;
1039 }
1040
1041 /*
1042  * Returns the number of system pages that are dirty.
1043  * This can be more than 1 if we find a huge-page HPTE.
1044  */
1045 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
1046 {
1047         struct revmap_entry *rev = kvm->arch.hpt.rev;
1048         unsigned long head, i, j;
1049         unsigned long n;
1050         unsigned long v, r;
1051         __be64 *hptep;
1052         int npages_dirty = 0;
1053
1054  retry:
1055         lock_rmap(rmapp);
1056         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
1057                 unlock_rmap(rmapp);
1058                 return npages_dirty;
1059         }
1060
1061         i = head = *rmapp & KVMPPC_RMAP_INDEX;
1062         do {
1063                 unsigned long hptep1;
1064                 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
1065                 j = rev[i].forw;
1066
1067                 /*
1068                  * Checking the C (changed) bit here is racy since there
1069                  * is no guarantee about when the hardware writes it back.
1070                  * If the HPTE is not writable then it is stable since the
1071                  * page can't be written to, and we would have done a tlbie
1072                  * (which forces the hardware to complete any writeback)
1073                  * when making the HPTE read-only.
1074                  * If vcpus are running then this call is racy anyway
1075                  * since the page could get dirtied subsequently, so we
1076                  * expect there to be a further call which would pick up
1077                  * any delayed C bit writeback.
1078                  * Otherwise we need to do the tlbie even if C==0 in
1079                  * order to pick up any delayed writeback of C.
1080                  */
1081                 hptep1 = be64_to_cpu(hptep[1]);
1082                 if (!(hptep1 & HPTE_R_C) &&
1083                     (!hpte_is_writable(hptep1) || vcpus_running(kvm)))
1084                         continue;
1085
1086                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
1087                         /* unlock rmap before spinning on the HPTE lock */
1088                         unlock_rmap(rmapp);
1089                         while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK))
1090                                 cpu_relax();
1091                         goto retry;
1092                 }
1093
1094                 /* Now check and modify the HPTE */
1095                 if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) {
1096                         __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
1097                         continue;
1098                 }
1099
1100                 /* need to make it temporarily absent so C is stable */
1101                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
1102                 kvmppc_invalidate_hpte(kvm, hptep, i);
1103                 v = be64_to_cpu(hptep[0]);
1104                 r = be64_to_cpu(hptep[1]);
1105                 if (r & HPTE_R_C) {
1106                         hptep[1] = cpu_to_be64(r & ~HPTE_R_C);
1107                         if (!(rev[i].guest_rpte & HPTE_R_C)) {
1108                                 rev[i].guest_rpte |= HPTE_R_C;
1109                                 note_hpte_modification(kvm, &rev[i]);
1110                         }
1111                         n = kvmppc_actual_pgsz(v, r);
1112                         n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT;
1113                         if (n > npages_dirty)
1114                                 npages_dirty = n;
1115                         eieio();
1116                 }
1117                 v &= ~HPTE_V_ABSENT;
1118                 v |= HPTE_V_VALID;
1119                 __unlock_hpte(hptep, v);
1120         } while ((i = j) != head);
1121
1122         unlock_rmap(rmapp);
1123         return npages_dirty;
1124 }
1125
1126 void kvmppc_harvest_vpa_dirty(struct kvmppc_vpa *vpa,
1127                               struct kvm_memory_slot *memslot,
1128                               unsigned long *map)
1129 {
1130         unsigned long gfn;
1131
1132         if (!vpa->dirty || !vpa->pinned_addr)
1133                 return;
1134         gfn = vpa->gpa >> PAGE_SHIFT;
1135         if (gfn < memslot->base_gfn ||
1136             gfn >= memslot->base_gfn + memslot->npages)
1137                 return;
1138
1139         vpa->dirty = false;
1140         if (map)
1141                 __set_bit_le(gfn - memslot->base_gfn, map);
1142 }
1143
1144 long kvmppc_hv_get_dirty_log_hpt(struct kvm *kvm,
1145                         struct kvm_memory_slot *memslot, unsigned long *map)
1146 {
1147         unsigned long i;
1148         unsigned long *rmapp;
1149
1150         preempt_disable();
1151         rmapp = memslot->arch.rmap;
1152         for (i = 0; i < memslot->npages; ++i) {
1153                 int npages = kvm_test_clear_dirty_npages(kvm, rmapp);
1154                 /*
1155                  * Note that if npages > 0 then i must be a multiple of npages,
1156                  * since we always put huge-page HPTEs in the rmap chain
1157                  * corresponding to their page base address.
1158                  */
1159                 if (npages)
1160                         set_dirty_bits(map, i, npages);
1161                 ++rmapp;
1162         }
1163         preempt_enable();
1164         return 0;
1165 }
1166
1167 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
1168                             unsigned long *nb_ret)
1169 {
1170         struct kvm_memory_slot *memslot;
1171         unsigned long gfn = gpa >> PAGE_SHIFT;
1172         struct page *page, *pages[1];
1173         int npages;
1174         unsigned long hva, offset;
1175         int srcu_idx;
1176
1177         srcu_idx = srcu_read_lock(&kvm->srcu);
1178         memslot = gfn_to_memslot(kvm, gfn);
1179         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
1180                 goto err;
1181         hva = gfn_to_hva_memslot(memslot, gfn);
1182         npages = get_user_pages_fast(hva, 1, 1, pages);
1183         if (npages < 1)
1184                 goto err;
1185         page = pages[0];
1186         srcu_read_unlock(&kvm->srcu, srcu_idx);
1187
1188         offset = gpa & (PAGE_SIZE - 1);
1189         if (nb_ret)
1190                 *nb_ret = PAGE_SIZE - offset;
1191         return page_address(page) + offset;
1192
1193  err:
1194         srcu_read_unlock(&kvm->srcu, srcu_idx);
1195         return NULL;
1196 }
1197
1198 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
1199                              bool dirty)
1200 {
1201         struct page *page = virt_to_page(va);
1202         struct kvm_memory_slot *memslot;
1203         unsigned long gfn;
1204         int srcu_idx;
1205
1206         put_page(page);
1207
1208         if (!dirty)
1209                 return;
1210
1211         /* We need to mark this page dirty in the memslot dirty_bitmap, if any */
1212         gfn = gpa >> PAGE_SHIFT;
1213         srcu_idx = srcu_read_lock(&kvm->srcu);
1214         memslot = gfn_to_memslot(kvm, gfn);
1215         if (memslot && memslot->dirty_bitmap)
1216                 set_bit_le(gfn - memslot->base_gfn, memslot->dirty_bitmap);
1217         srcu_read_unlock(&kvm->srcu, srcu_idx);
1218 }
1219
1220 /*
1221  * HPT resizing
1222  */
1223 static int resize_hpt_allocate(struct kvm_resize_hpt *resize)
1224 {
1225         int rc;
1226
1227         rc = kvmppc_allocate_hpt(&resize->hpt, resize->order);
1228         if (rc < 0)
1229                 return rc;
1230
1231         resize_hpt_debug(resize, "resize_hpt_allocate(): HPT @ 0x%lx\n",
1232                          resize->hpt.virt);
1233
1234         return 0;
1235 }
1236
1237 static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize,
1238                                             unsigned long idx)
1239 {
1240         struct kvm *kvm = resize->kvm;
1241         struct kvm_hpt_info *old = &kvm->arch.hpt;
1242         struct kvm_hpt_info *new = &resize->hpt;
1243         unsigned long old_hash_mask = (1ULL << (old->order - 7)) - 1;
1244         unsigned long new_hash_mask = (1ULL << (new->order - 7)) - 1;
1245         __be64 *hptep, *new_hptep;
1246         unsigned long vpte, rpte, guest_rpte;
1247         int ret;
1248         struct revmap_entry *rev;
1249         unsigned long apsize, avpn, pteg, hash;
1250         unsigned long new_idx, new_pteg, replace_vpte;
1251         int pshift;
1252
1253         hptep = (__be64 *)(old->virt + (idx << 4));
1254
1255         /* Guest is stopped, so new HPTEs can't be added or faulted
1256          * in, only unmapped or altered by host actions.  So, it's
1257          * safe to check this before we take the HPTE lock */
1258         vpte = be64_to_cpu(hptep[0]);
1259         if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
1260                 return 0; /* nothing to do */
1261
1262         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
1263                 cpu_relax();
1264
1265         vpte = be64_to_cpu(hptep[0]);
1266
1267         ret = 0;
1268         if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
1269                 /* Nothing to do */
1270                 goto out;
1271
1272         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1273                 rpte = be64_to_cpu(hptep[1]);
1274                 vpte = hpte_new_to_old_v(vpte, rpte);
1275         }
1276
1277         /* Unmap */
1278         rev = &old->rev[idx];
1279         guest_rpte = rev->guest_rpte;
1280
1281         ret = -EIO;
1282         apsize = kvmppc_actual_pgsz(vpte, guest_rpte);
1283         if (!apsize)
1284                 goto out;
1285
1286         if (vpte & HPTE_V_VALID) {
1287                 unsigned long gfn = hpte_rpn(guest_rpte, apsize);
1288                 int srcu_idx = srcu_read_lock(&kvm->srcu);
1289                 struct kvm_memory_slot *memslot =
1290                         __gfn_to_memslot(kvm_memslots(kvm), gfn);
1291
1292                 if (memslot) {
1293                         unsigned long *rmapp;
1294                         rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1295
1296                         lock_rmap(rmapp);
1297                         kvmppc_unmap_hpte(kvm, idx, memslot, rmapp, gfn);
1298                         unlock_rmap(rmapp);
1299                 }
1300
1301                 srcu_read_unlock(&kvm->srcu, srcu_idx);
1302         }
1303
1304         /* Reload PTE after unmap */
1305         vpte = be64_to_cpu(hptep[0]);
1306         BUG_ON(vpte & HPTE_V_VALID);
1307         BUG_ON(!(vpte & HPTE_V_ABSENT));
1308
1309         ret = 0;
1310         if (!(vpte & HPTE_V_BOLTED))
1311                 goto out;
1312
1313         rpte = be64_to_cpu(hptep[1]);
1314
1315         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1316                 vpte = hpte_new_to_old_v(vpte, rpte);
1317                 rpte = hpte_new_to_old_r(rpte);
1318         }
1319
1320         pshift = kvmppc_hpte_base_page_shift(vpte, rpte);
1321         avpn = HPTE_V_AVPN_VAL(vpte) & ~(((1ul << pshift) - 1) >> 23);
1322         pteg = idx / HPTES_PER_GROUP;
1323         if (vpte & HPTE_V_SECONDARY)
1324                 pteg = ~pteg;
1325
1326         if (!(vpte & HPTE_V_1TB_SEG)) {
1327                 unsigned long offset, vsid;
1328
1329                 /* We only have 28 - 23 bits of offset in avpn */
1330                 offset = (avpn & 0x1f) << 23;
1331                 vsid = avpn >> 5;
1332                 /* We can find more bits from the pteg value */
1333                 if (pshift < 23)
1334                         offset |= ((vsid ^ pteg) & old_hash_mask) << pshift;
1335
1336                 hash = vsid ^ (offset >> pshift);
1337         } else {
1338                 unsigned long offset, vsid;
1339
1340                 /* We only have 40 - 23 bits of seg_off in avpn */
1341                 offset = (avpn & 0x1ffff) << 23;
1342                 vsid = avpn >> 17;
1343                 if (pshift < 23)
1344                         offset |= ((vsid ^ (vsid << 25) ^ pteg) & old_hash_mask) << pshift;
1345
1346                 hash = vsid ^ (vsid << 25) ^ (offset >> pshift);
1347         }
1348
1349         new_pteg = hash & new_hash_mask;
1350         if (vpte & HPTE_V_SECONDARY)
1351                 new_pteg = ~hash & new_hash_mask;
1352
1353         new_idx = new_pteg * HPTES_PER_GROUP + (idx % HPTES_PER_GROUP);
1354         new_hptep = (__be64 *)(new->virt + (new_idx << 4));
1355
1356         replace_vpte = be64_to_cpu(new_hptep[0]);
1357         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1358                 unsigned long replace_rpte = be64_to_cpu(new_hptep[1]);
1359                 replace_vpte = hpte_new_to_old_v(replace_vpte, replace_rpte);
1360         }
1361
1362         if (replace_vpte & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1363                 BUG_ON(new->order >= old->order);
1364
1365                 if (replace_vpte & HPTE_V_BOLTED) {
1366                         if (vpte & HPTE_V_BOLTED)
1367                                 /* Bolted collision, nothing we can do */
1368                                 ret = -ENOSPC;
1369                         /* Discard the new HPTE */
1370                         goto out;
1371                 }
1372
1373                 /* Discard the previous HPTE */
1374         }
1375
1376         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1377                 rpte = hpte_old_to_new_r(vpte, rpte);
1378                 vpte = hpte_old_to_new_v(vpte);
1379         }
1380
1381         new_hptep[1] = cpu_to_be64(rpte);
1382         new->rev[new_idx].guest_rpte = guest_rpte;
1383         /* No need for a barrier, since new HPT isn't active */
1384         new_hptep[0] = cpu_to_be64(vpte);
1385         unlock_hpte(new_hptep, vpte);
1386
1387 out:
1388         unlock_hpte(hptep, vpte);
1389         return ret;
1390 }
1391
1392 static int resize_hpt_rehash(struct kvm_resize_hpt *resize)
1393 {
1394         struct kvm *kvm = resize->kvm;
1395         unsigned  long i;
1396         int rc;
1397
1398         for (i = 0; i < kvmppc_hpt_npte(&kvm->arch.hpt); i++) {
1399                 rc = resize_hpt_rehash_hpte(resize, i);
1400                 if (rc != 0)
1401                         return rc;
1402         }
1403
1404         return 0;
1405 }
1406
1407 static void resize_hpt_pivot(struct kvm_resize_hpt *resize)
1408 {
1409         struct kvm *kvm = resize->kvm;
1410         struct kvm_hpt_info hpt_tmp;
1411
1412         /* Exchange the pending tables in the resize structure with
1413          * the active tables */
1414
1415         resize_hpt_debug(resize, "resize_hpt_pivot()\n");
1416
1417         spin_lock(&kvm->mmu_lock);
1418         asm volatile("ptesync" : : : "memory");
1419
1420         hpt_tmp = kvm->arch.hpt;
1421         kvmppc_set_hpt(kvm, &resize->hpt);
1422         resize->hpt = hpt_tmp;
1423
1424         spin_unlock(&kvm->mmu_lock);
1425
1426         synchronize_srcu_expedited(&kvm->srcu);
1427
1428         if (cpu_has_feature(CPU_FTR_ARCH_300))
1429                 kvmppc_setup_partition_table(kvm);
1430
1431         resize_hpt_debug(resize, "resize_hpt_pivot() done\n");
1432 }
1433
1434 static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize)
1435 {
1436         if (WARN_ON(!mutex_is_locked(&kvm->lock)))
1437                 return;
1438
1439         if (!resize)
1440                 return;
1441
1442         if (resize->error != -EBUSY) {
1443                 if (resize->hpt.virt)
1444                         kvmppc_free_hpt(&resize->hpt);
1445                 kfree(resize);
1446         }
1447
1448         if (kvm->arch.resize_hpt == resize)
1449                 kvm->arch.resize_hpt = NULL;
1450 }
1451
1452 static void resize_hpt_prepare_work(struct work_struct *work)
1453 {
1454         struct kvm_resize_hpt *resize = container_of(work,
1455                                                      struct kvm_resize_hpt,
1456                                                      work);
1457         struct kvm *kvm = resize->kvm;
1458         int err = 0;
1459
1460         if (WARN_ON(resize->error != -EBUSY))
1461                 return;
1462
1463         mutex_lock(&kvm->lock);
1464
1465         /* Request is still current? */
1466         if (kvm->arch.resize_hpt == resize) {
1467                 /* We may request large allocations here:
1468                  * do not sleep with kvm->lock held for a while.
1469                  */
1470                 mutex_unlock(&kvm->lock);
1471
1472                 resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n",
1473                                  resize->order);
1474
1475                 err = resize_hpt_allocate(resize);
1476
1477                 /* We have strict assumption about -EBUSY
1478                  * when preparing for HPT resize.
1479                  */
1480                 if (WARN_ON(err == -EBUSY))
1481                         err = -EINPROGRESS;
1482
1483                 mutex_lock(&kvm->lock);
1484                 /* It is possible that kvm->arch.resize_hpt != resize
1485                  * after we grab kvm->lock again.
1486                  */
1487         }
1488
1489         resize->error = err;
1490
1491         if (kvm->arch.resize_hpt != resize)
1492                 resize_hpt_release(kvm, resize);
1493
1494         mutex_unlock(&kvm->lock);
1495 }
1496
1497 long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
1498                                      struct kvm_ppc_resize_hpt *rhpt)
1499 {
1500         unsigned long flags = rhpt->flags;
1501         unsigned long shift = rhpt->shift;
1502         struct kvm_resize_hpt *resize;
1503         int ret;
1504
1505         if (flags != 0 || kvm_is_radix(kvm))
1506                 return -EINVAL;
1507
1508         if (shift && ((shift < 18) || (shift > 46)))
1509                 return -EINVAL;
1510
1511         mutex_lock(&kvm->lock);
1512
1513         resize = kvm->arch.resize_hpt;
1514
1515         if (resize) {
1516                 if (resize->order == shift) {
1517                         /* Suitable resize in progress? */
1518                         ret = resize->error;
1519                         if (ret == -EBUSY)
1520                                 ret = 100; /* estimated time in ms */
1521                         else if (ret)
1522                                 resize_hpt_release(kvm, resize);
1523
1524                         goto out;
1525                 }
1526
1527                 /* not suitable, cancel it */
1528                 resize_hpt_release(kvm, resize);
1529         }
1530
1531         ret = 0;
1532         if (!shift)
1533                 goto out; /* nothing to do */
1534
1535         /* start new resize */
1536
1537         resize = kzalloc(sizeof(*resize), GFP_KERNEL);
1538         if (!resize) {
1539                 ret = -ENOMEM;
1540                 goto out;
1541         }
1542
1543         resize->error = -EBUSY;
1544         resize->order = shift;
1545         resize->kvm = kvm;
1546         INIT_WORK(&resize->work, resize_hpt_prepare_work);
1547         kvm->arch.resize_hpt = resize;
1548
1549         schedule_work(&resize->work);
1550
1551         ret = 100; /* estimated time in ms */
1552
1553 out:
1554         mutex_unlock(&kvm->lock);
1555         return ret;
1556 }
1557
1558 static void resize_hpt_boot_vcpu(void *opaque)
1559 {
1560         /* Nothing to do, just force a KVM exit */
1561 }
1562
1563 long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
1564                                     struct kvm_ppc_resize_hpt *rhpt)
1565 {
1566         unsigned long flags = rhpt->flags;
1567         unsigned long shift = rhpt->shift;
1568         struct kvm_resize_hpt *resize;
1569         long ret;
1570
1571         if (flags != 0 || kvm_is_radix(kvm))
1572                 return -EINVAL;
1573
1574         if (shift && ((shift < 18) || (shift > 46)))
1575                 return -EINVAL;
1576
1577         mutex_lock(&kvm->lock);
1578
1579         resize = kvm->arch.resize_hpt;
1580
1581         /* This shouldn't be possible */
1582         ret = -EIO;
1583         if (WARN_ON(!kvm->arch.mmu_ready))
1584                 goto out_no_hpt;
1585
1586         /* Stop VCPUs from running while we mess with the HPT */
1587         kvm->arch.mmu_ready = 0;
1588         smp_mb();
1589
1590         /* Boot all CPUs out of the guest so they re-read
1591          * mmu_ready */
1592         on_each_cpu(resize_hpt_boot_vcpu, NULL, 1);
1593
1594         ret = -ENXIO;
1595         if (!resize || (resize->order != shift))
1596                 goto out;
1597
1598         ret = resize->error;
1599         if (ret)
1600                 goto out;
1601
1602         ret = resize_hpt_rehash(resize);
1603         if (ret)
1604                 goto out;
1605
1606         resize_hpt_pivot(resize);
1607
1608 out:
1609         /* Let VCPUs run again */
1610         kvm->arch.mmu_ready = 1;
1611         smp_mb();
1612 out_no_hpt:
1613         resize_hpt_release(kvm, resize);
1614         mutex_unlock(&kvm->lock);
1615         return ret;
1616 }
1617
1618 /*
1619  * Functions for reading and writing the hash table via reads and
1620  * writes on a file descriptor.
1621  *
1622  * Reads return the guest view of the hash table, which has to be
1623  * pieced together from the real hash table and the guest_rpte
1624  * values in the revmap array.
1625  *
1626  * On writes, each HPTE written is considered in turn, and if it
1627  * is valid, it is written to the HPT as if an H_ENTER with the
1628  * exact flag set was done.  When the invalid count is non-zero
1629  * in the header written to the stream, the kernel will make
1630  * sure that that many HPTEs are invalid, and invalidate them
1631  * if not.
1632  */
1633
1634 struct kvm_htab_ctx {
1635         unsigned long   index;
1636         unsigned long   flags;
1637         struct kvm      *kvm;
1638         int             first_pass;
1639 };
1640
1641 #define HPTE_SIZE       (2 * sizeof(unsigned long))
1642
1643 /*
1644  * Returns 1 if this HPT entry has been modified or has pending
1645  * R/C bit changes.
1646  */
1647 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp)
1648 {
1649         unsigned long rcbits_unset;
1650
1651         if (revp->guest_rpte & HPTE_GR_MODIFIED)
1652                 return 1;
1653
1654         /* Also need to consider changes in reference and changed bits */
1655         rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1656         if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) &&
1657             (be64_to_cpu(hptp[1]) & rcbits_unset))
1658                 return 1;
1659
1660         return 0;
1661 }
1662
1663 static long record_hpte(unsigned long flags, __be64 *hptp,
1664                         unsigned long *hpte, struct revmap_entry *revp,
1665                         int want_valid, int first_pass)
1666 {
1667         unsigned long v, r, hr;
1668         unsigned long rcbits_unset;
1669         int ok = 1;
1670         int valid, dirty;
1671
1672         /* Unmodified entries are uninteresting except on the first pass */
1673         dirty = hpte_dirty(revp, hptp);
1674         if (!first_pass && !dirty)
1675                 return 0;
1676
1677         valid = 0;
1678         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1679                 valid = 1;
1680                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1681                     !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED))
1682                         valid = 0;
1683         }
1684         if (valid != want_valid)
1685                 return 0;
1686
1687         v = r = 0;
1688         if (valid || dirty) {
1689                 /* lock the HPTE so it's stable and read it */
1690                 preempt_disable();
1691                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1692                         cpu_relax();
1693                 v = be64_to_cpu(hptp[0]);
1694                 hr = be64_to_cpu(hptp[1]);
1695                 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1696                         v = hpte_new_to_old_v(v, hr);
1697                         hr = hpte_new_to_old_r(hr);
1698                 }
1699
1700                 /* re-evaluate valid and dirty from synchronized HPTE value */
1701                 valid = !!(v & HPTE_V_VALID);
1702                 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1703
1704                 /* Harvest R and C into guest view if necessary */
1705                 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1706                 if (valid && (rcbits_unset & hr)) {
1707                         revp->guest_rpte |= (hr &
1708                                 (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED;
1709                         dirty = 1;
1710                 }
1711
1712                 if (v & HPTE_V_ABSENT) {
1713                         v &= ~HPTE_V_ABSENT;
1714                         v |= HPTE_V_VALID;
1715                         valid = 1;
1716                 }
1717                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1718                         valid = 0;
1719
1720                 r = revp->guest_rpte;
1721                 /* only clear modified if this is the right sort of entry */
1722                 if (valid == want_valid && dirty) {
1723                         r &= ~HPTE_GR_MODIFIED;
1724                         revp->guest_rpte = r;
1725                 }
1726                 unlock_hpte(hptp, be64_to_cpu(hptp[0]));
1727                 preempt_enable();
1728                 if (!(valid == want_valid && (first_pass || dirty)))
1729                         ok = 0;
1730         }
1731         hpte[0] = cpu_to_be64(v);
1732         hpte[1] = cpu_to_be64(r);
1733         return ok;
1734 }
1735
1736 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1737                              size_t count, loff_t *ppos)
1738 {
1739         struct kvm_htab_ctx *ctx = file->private_data;
1740         struct kvm *kvm = ctx->kvm;
1741         struct kvm_get_htab_header hdr;
1742         __be64 *hptp;
1743         struct revmap_entry *revp;
1744         unsigned long i, nb, nw;
1745         unsigned long __user *lbuf;
1746         struct kvm_get_htab_header __user *hptr;
1747         unsigned long flags;
1748         int first_pass;
1749         unsigned long hpte[2];
1750
1751         if (!access_ok(VERIFY_WRITE, buf, count))
1752                 return -EFAULT;
1753         if (kvm_is_radix(kvm))
1754                 return 0;
1755
1756         first_pass = ctx->first_pass;
1757         flags = ctx->flags;
1758
1759         i = ctx->index;
1760         hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1761         revp = kvm->arch.hpt.rev + i;
1762         lbuf = (unsigned long __user *)buf;
1763
1764         nb = 0;
1765         while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1766                 /* Initialize header */
1767                 hptr = (struct kvm_get_htab_header __user *)buf;
1768                 hdr.n_valid = 0;
1769                 hdr.n_invalid = 0;
1770                 nw = nb;
1771                 nb += sizeof(hdr);
1772                 lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1773
1774                 /* Skip uninteresting entries, i.e. clean on not-first pass */
1775                 if (!first_pass) {
1776                         while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1777                                !hpte_dirty(revp, hptp)) {
1778                                 ++i;
1779                                 hptp += 2;
1780                                 ++revp;
1781                         }
1782                 }
1783                 hdr.index = i;
1784
1785                 /* Grab a series of valid entries */
1786                 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1787                        hdr.n_valid < 0xffff &&
1788                        nb + HPTE_SIZE < count &&
1789                        record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1790                         /* valid entry, write it out */
1791                         ++hdr.n_valid;
1792                         if (__put_user(hpte[0], lbuf) ||
1793                             __put_user(hpte[1], lbuf + 1))
1794                                 return -EFAULT;
1795                         nb += HPTE_SIZE;
1796                         lbuf += 2;
1797                         ++i;
1798                         hptp += 2;
1799                         ++revp;
1800                 }
1801                 /* Now skip invalid entries while we can */
1802                 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1803                        hdr.n_invalid < 0xffff &&
1804                        record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1805                         /* found an invalid entry */
1806                         ++hdr.n_invalid;
1807                         ++i;
1808                         hptp += 2;
1809                         ++revp;
1810                 }
1811
1812                 if (hdr.n_valid || hdr.n_invalid) {
1813                         /* write back the header */
1814                         if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1815                                 return -EFAULT;
1816                         nw = nb;
1817                         buf = (char __user *)lbuf;
1818                 } else {
1819                         nb = nw;
1820                 }
1821
1822                 /* Check if we've wrapped around the hash table */
1823                 if (i >= kvmppc_hpt_npte(&kvm->arch.hpt)) {
1824                         i = 0;
1825                         ctx->first_pass = 0;
1826                         break;
1827                 }
1828         }
1829
1830         ctx->index = i;
1831
1832         return nb;
1833 }
1834
1835 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1836                               size_t count, loff_t *ppos)
1837 {
1838         struct kvm_htab_ctx *ctx = file->private_data;
1839         struct kvm *kvm = ctx->kvm;
1840         struct kvm_get_htab_header hdr;
1841         unsigned long i, j;
1842         unsigned long v, r;
1843         unsigned long __user *lbuf;
1844         __be64 *hptp;
1845         unsigned long tmp[2];
1846         ssize_t nb;
1847         long int err, ret;
1848         int mmu_ready;
1849         int pshift;
1850
1851         if (!access_ok(VERIFY_READ, buf, count))
1852                 return -EFAULT;
1853         if (kvm_is_radix(kvm))
1854                 return -EINVAL;
1855
1856         /* lock out vcpus from running while we're doing this */
1857         mutex_lock(&kvm->lock);
1858         mmu_ready = kvm->arch.mmu_ready;
1859         if (mmu_ready) {
1860                 kvm->arch.mmu_ready = 0;        /* temporarily */
1861                 /* order mmu_ready vs. vcpus_running */
1862                 smp_mb();
1863                 if (atomic_read(&kvm->arch.vcpus_running)) {
1864                         kvm->arch.mmu_ready = 1;
1865                         mutex_unlock(&kvm->lock);
1866                         return -EBUSY;
1867                 }
1868         }
1869
1870         err = 0;
1871         for (nb = 0; nb + sizeof(hdr) <= count; ) {
1872                 err = -EFAULT;
1873                 if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1874                         break;
1875
1876                 err = 0;
1877                 if (nb + hdr.n_valid * HPTE_SIZE > count)
1878                         break;
1879
1880                 nb += sizeof(hdr);
1881                 buf += sizeof(hdr);
1882
1883                 err = -EINVAL;
1884                 i = hdr.index;
1885                 if (i >= kvmppc_hpt_npte(&kvm->arch.hpt) ||
1886                     i + hdr.n_valid + hdr.n_invalid > kvmppc_hpt_npte(&kvm->arch.hpt))
1887                         break;
1888
1889                 hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1890                 lbuf = (unsigned long __user *)buf;
1891                 for (j = 0; j < hdr.n_valid; ++j) {
1892                         __be64 hpte_v;
1893                         __be64 hpte_r;
1894
1895                         err = -EFAULT;
1896                         if (__get_user(hpte_v, lbuf) ||
1897                             __get_user(hpte_r, lbuf + 1))
1898                                 goto out;
1899                         v = be64_to_cpu(hpte_v);
1900                         r = be64_to_cpu(hpte_r);
1901                         err = -EINVAL;
1902                         if (!(v & HPTE_V_VALID))
1903                                 goto out;
1904                         pshift = kvmppc_hpte_base_page_shift(v, r);
1905                         if (pshift <= 0)
1906                                 goto out;
1907                         lbuf += 2;
1908                         nb += HPTE_SIZE;
1909
1910                         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1911                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1912                         err = -EIO;
1913                         ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1914                                                          tmp);
1915                         if (ret != H_SUCCESS) {
1916                                 pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
1917                                        "r=%lx\n", ret, i, v, r);
1918                                 goto out;
1919                         }
1920                         if (!mmu_ready && is_vrma_hpte(v)) {
1921                                 unsigned long senc, lpcr;
1922
1923                                 senc = slb_pgsize_encoding(1ul << pshift);
1924                                 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1925                                         (VRMA_VSID << SLB_VSID_SHIFT_1T);
1926                                 if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
1927                                         lpcr = senc << (LPCR_VRMASD_SH - 4);
1928                                         kvmppc_update_lpcr(kvm, lpcr,
1929                                                            LPCR_VRMASD);
1930                                 } else {
1931                                         kvmppc_setup_partition_table(kvm);
1932                                 }
1933                                 mmu_ready = 1;
1934                         }
1935                         ++i;
1936                         hptp += 2;
1937                 }
1938
1939                 for (j = 0; j < hdr.n_invalid; ++j) {
1940                         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1941                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1942                         ++i;
1943                         hptp += 2;
1944                 }
1945                 err = 0;
1946         }
1947
1948  out:
1949         /* Order HPTE updates vs. mmu_ready */
1950         smp_wmb();
1951         kvm->arch.mmu_ready = mmu_ready;
1952         mutex_unlock(&kvm->lock);
1953
1954         if (err)
1955                 return err;
1956         return nb;
1957 }
1958
1959 static int kvm_htab_release(struct inode *inode, struct file *filp)
1960 {
1961         struct kvm_htab_ctx *ctx = filp->private_data;
1962
1963         filp->private_data = NULL;
1964         if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1965                 atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1966         kvm_put_kvm(ctx->kvm);
1967         kfree(ctx);
1968         return 0;
1969 }
1970
1971 static const struct file_operations kvm_htab_fops = {
1972         .read           = kvm_htab_read,
1973         .write          = kvm_htab_write,
1974         .llseek         = default_llseek,
1975         .release        = kvm_htab_release,
1976 };
1977
1978 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1979 {
1980         int ret;
1981         struct kvm_htab_ctx *ctx;
1982         int rwflag;
1983
1984         /* reject flags we don't recognize */
1985         if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1986                 return -EINVAL;
1987         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1988         if (!ctx)
1989                 return -ENOMEM;
1990         kvm_get_kvm(kvm);
1991         ctx->kvm = kvm;
1992         ctx->index = ghf->start_index;
1993         ctx->flags = ghf->flags;
1994         ctx->first_pass = 1;
1995
1996         rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1997         ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
1998         if (ret < 0) {
1999                 kfree(ctx);
2000                 kvm_put_kvm(kvm);
2001                 return ret;
2002         }
2003
2004         if (rwflag == O_RDONLY) {
2005                 mutex_lock(&kvm->slots_lock);
2006                 atomic_inc(&kvm->arch.hpte_mod_interest);
2007                 /* make sure kvmppc_do_h_enter etc. see the increment */
2008                 synchronize_srcu_expedited(&kvm->srcu);
2009                 mutex_unlock(&kvm->slots_lock);
2010         }
2011
2012         return ret;
2013 }
2014
2015 struct debugfs_htab_state {
2016         struct kvm      *kvm;
2017         struct mutex    mutex;
2018         unsigned long   hpt_index;
2019         int             chars_left;
2020         int             buf_index;
2021         char            buf[64];
2022 };
2023
2024 static int debugfs_htab_open(struct inode *inode, struct file *file)
2025 {
2026         struct kvm *kvm = inode->i_private;
2027         struct debugfs_htab_state *p;
2028
2029         p = kzalloc(sizeof(*p), GFP_KERNEL);
2030         if (!p)
2031                 return -ENOMEM;
2032
2033         kvm_get_kvm(kvm);
2034         p->kvm = kvm;
2035         mutex_init(&p->mutex);
2036         file->private_data = p;
2037
2038         return nonseekable_open(inode, file);
2039 }
2040
2041 static int debugfs_htab_release(struct inode *inode, struct file *file)
2042 {
2043         struct debugfs_htab_state *p = file->private_data;
2044
2045         kvm_put_kvm(p->kvm);
2046         kfree(p);
2047         return 0;
2048 }
2049
2050 static ssize_t debugfs_htab_read(struct file *file, char __user *buf,
2051                                  size_t len, loff_t *ppos)
2052 {
2053         struct debugfs_htab_state *p = file->private_data;
2054         ssize_t ret, r;
2055         unsigned long i, n;
2056         unsigned long v, hr, gr;
2057         struct kvm *kvm;
2058         __be64 *hptp;
2059
2060         kvm = p->kvm;
2061         if (kvm_is_radix(kvm))
2062                 return 0;
2063
2064         ret = mutex_lock_interruptible(&p->mutex);
2065         if (ret)
2066                 return ret;
2067
2068         if (p->chars_left) {
2069                 n = p->chars_left;
2070                 if (n > len)
2071                         n = len;
2072                 r = copy_to_user(buf, p->buf + p->buf_index, n);
2073                 n -= r;
2074                 p->chars_left -= n;
2075                 p->buf_index += n;
2076                 buf += n;
2077                 len -= n;
2078                 ret = n;
2079                 if (r) {
2080                         if (!n)
2081                                 ret = -EFAULT;
2082                         goto out;
2083                 }
2084         }
2085
2086         i = p->hpt_index;
2087         hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
2088         for (; len != 0 && i < kvmppc_hpt_npte(&kvm->arch.hpt);
2089              ++i, hptp += 2) {
2090                 if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)))
2091                         continue;
2092
2093                 /* lock the HPTE so it's stable and read it */
2094                 preempt_disable();
2095                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
2096                         cpu_relax();
2097                 v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK;
2098                 hr = be64_to_cpu(hptp[1]);
2099                 gr = kvm->arch.hpt.rev[i].guest_rpte;
2100                 unlock_hpte(hptp, v);
2101                 preempt_enable();
2102
2103                 if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
2104                         continue;
2105
2106                 n = scnprintf(p->buf, sizeof(p->buf),
2107                               "%6lx %.16lx %.16lx %.16lx\n",
2108                               i, v, hr, gr);
2109                 p->chars_left = n;
2110                 if (n > len)
2111                         n = len;
2112                 r = copy_to_user(buf, p->buf, n);
2113                 n -= r;
2114                 p->chars_left -= n;
2115                 p->buf_index = n;
2116                 buf += n;
2117                 len -= n;
2118                 ret += n;
2119                 if (r) {
2120                         if (!ret)
2121                                 ret = -EFAULT;
2122                         goto out;
2123                 }
2124         }
2125         p->hpt_index = i;
2126
2127  out:
2128         mutex_unlock(&p->mutex);
2129         return ret;
2130 }
2131
2132 static ssize_t debugfs_htab_write(struct file *file, const char __user *buf,
2133                            size_t len, loff_t *ppos)
2134 {
2135         return -EACCES;
2136 }
2137
2138 static const struct file_operations debugfs_htab_fops = {
2139         .owner   = THIS_MODULE,
2140         .open    = debugfs_htab_open,
2141         .release = debugfs_htab_release,
2142         .read    = debugfs_htab_read,
2143         .write   = debugfs_htab_write,
2144         .llseek  = generic_file_llseek,
2145 };
2146
2147 void kvmppc_mmu_debugfs_init(struct kvm *kvm)
2148 {
2149         kvm->arch.htab_dentry = debugfs_create_file("htab", 0400,
2150                                                     kvm->arch.debugfs_dir, kvm,
2151                                                     &debugfs_htab_fops);
2152 }
2153
2154 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
2155 {
2156         struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
2157
2158         vcpu->arch.slb_nr = 32;         /* POWER7/POWER8 */
2159
2160         mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
2161         mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
2162
2163         vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
2164 }