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         /* Unmap */
1273         rev = &old->rev[idx];
1274         guest_rpte = rev->guest_rpte;
1275
1276         ret = -EIO;
1277         apsize = kvmppc_actual_pgsz(vpte, guest_rpte);
1278         if (!apsize)
1279                 goto out;
1280
1281         if (vpte & HPTE_V_VALID) {
1282                 unsigned long gfn = hpte_rpn(guest_rpte, apsize);
1283                 int srcu_idx = srcu_read_lock(&kvm->srcu);
1284                 struct kvm_memory_slot *memslot =
1285                         __gfn_to_memslot(kvm_memslots(kvm), gfn);
1286
1287                 if (memslot) {
1288                         unsigned long *rmapp;
1289                         rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1290
1291                         lock_rmap(rmapp);
1292                         kvmppc_unmap_hpte(kvm, idx, memslot, rmapp, gfn);
1293                         unlock_rmap(rmapp);
1294                 }
1295
1296                 srcu_read_unlock(&kvm->srcu, srcu_idx);
1297         }
1298
1299         /* Reload PTE after unmap */
1300         vpte = be64_to_cpu(hptep[0]);
1301
1302         BUG_ON(vpte & HPTE_V_VALID);
1303         BUG_ON(!(vpte & HPTE_V_ABSENT));
1304
1305         ret = 0;
1306         if (!(vpte & HPTE_V_BOLTED))
1307                 goto out;
1308
1309         rpte = be64_to_cpu(hptep[1]);
1310         pshift = kvmppc_hpte_base_page_shift(vpte, rpte);
1311         avpn = HPTE_V_AVPN_VAL(vpte) & ~(((1ul << pshift) - 1) >> 23);
1312         pteg = idx / HPTES_PER_GROUP;
1313         if (vpte & HPTE_V_SECONDARY)
1314                 pteg = ~pteg;
1315
1316         if (!(vpte & HPTE_V_1TB_SEG)) {
1317                 unsigned long offset, vsid;
1318
1319                 /* We only have 28 - 23 bits of offset in avpn */
1320                 offset = (avpn & 0x1f) << 23;
1321                 vsid = avpn >> 5;
1322                 /* We can find more bits from the pteg value */
1323                 if (pshift < 23)
1324                         offset |= ((vsid ^ pteg) & old_hash_mask) << pshift;
1325
1326                 hash = vsid ^ (offset >> pshift);
1327         } else {
1328                 unsigned long offset, vsid;
1329
1330                 /* We only have 40 - 23 bits of seg_off in avpn */
1331                 offset = (avpn & 0x1ffff) << 23;
1332                 vsid = avpn >> 17;
1333                 if (pshift < 23)
1334                         offset |= ((vsid ^ (vsid << 25) ^ pteg) & old_hash_mask) << pshift;
1335
1336                 hash = vsid ^ (vsid << 25) ^ (offset >> pshift);
1337         }
1338
1339         new_pteg = hash & new_hash_mask;
1340         if (vpte & HPTE_V_SECONDARY) {
1341                 BUG_ON(~pteg != (hash & old_hash_mask));
1342                 new_pteg = ~new_pteg;
1343         } else {
1344                 BUG_ON(pteg != (hash & old_hash_mask));
1345         }
1346
1347         new_idx = new_pteg * HPTES_PER_GROUP + (idx % HPTES_PER_GROUP);
1348         new_hptep = (__be64 *)(new->virt + (new_idx << 4));
1349
1350         replace_vpte = be64_to_cpu(new_hptep[0]);
1351
1352         if (replace_vpte & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1353                 BUG_ON(new->order >= old->order);
1354
1355                 if (replace_vpte & HPTE_V_BOLTED) {
1356                         if (vpte & HPTE_V_BOLTED)
1357                                 /* Bolted collision, nothing we can do */
1358                                 ret = -ENOSPC;
1359                         /* Discard the new HPTE */
1360                         goto out;
1361                 }
1362
1363                 /* Discard the previous HPTE */
1364         }
1365
1366         new_hptep[1] = cpu_to_be64(rpte);
1367         new->rev[new_idx].guest_rpte = guest_rpte;
1368         /* No need for a barrier, since new HPT isn't active */
1369         new_hptep[0] = cpu_to_be64(vpte);
1370         unlock_hpte(new_hptep, vpte);
1371
1372 out:
1373         unlock_hpte(hptep, vpte);
1374         return ret;
1375 }
1376
1377 static int resize_hpt_rehash(struct kvm_resize_hpt *resize)
1378 {
1379         struct kvm *kvm = resize->kvm;
1380         unsigned  long i;
1381         int rc;
1382
1383         /*
1384          * resize_hpt_rehash_hpte() doesn't handle the new-format HPTEs
1385          * that POWER9 uses, and could well hit a BUG_ON on POWER9.
1386          */
1387         if (cpu_has_feature(CPU_FTR_ARCH_300))
1388                 return -EIO;
1389         for (i = 0; i < kvmppc_hpt_npte(&kvm->arch.hpt); i++) {
1390                 rc = resize_hpt_rehash_hpte(resize, i);
1391                 if (rc != 0)
1392                         return rc;
1393         }
1394
1395         return 0;
1396 }
1397
1398 static void resize_hpt_pivot(struct kvm_resize_hpt *resize)
1399 {
1400         struct kvm *kvm = resize->kvm;
1401         struct kvm_hpt_info hpt_tmp;
1402
1403         /* Exchange the pending tables in the resize structure with
1404          * the active tables */
1405
1406         resize_hpt_debug(resize, "resize_hpt_pivot()\n");
1407
1408         spin_lock(&kvm->mmu_lock);
1409         asm volatile("ptesync" : : : "memory");
1410
1411         hpt_tmp = kvm->arch.hpt;
1412         kvmppc_set_hpt(kvm, &resize->hpt);
1413         resize->hpt = hpt_tmp;
1414
1415         spin_unlock(&kvm->mmu_lock);
1416
1417         synchronize_srcu_expedited(&kvm->srcu);
1418
1419         resize_hpt_debug(resize, "resize_hpt_pivot() done\n");
1420 }
1421
1422 static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize)
1423 {
1424         if (WARN_ON(!mutex_is_locked(&kvm->lock)))
1425                 return;
1426
1427         if (!resize)
1428                 return;
1429
1430         if (resize->error != -EBUSY) {
1431                 if (resize->hpt.virt)
1432                         kvmppc_free_hpt(&resize->hpt);
1433                 kfree(resize);
1434         }
1435
1436         if (kvm->arch.resize_hpt == resize)
1437                 kvm->arch.resize_hpt = NULL;
1438 }
1439
1440 static void resize_hpt_prepare_work(struct work_struct *work)
1441 {
1442         struct kvm_resize_hpt *resize = container_of(work,
1443                                                      struct kvm_resize_hpt,
1444                                                      work);
1445         struct kvm *kvm = resize->kvm;
1446         int err = 0;
1447
1448         if (WARN_ON(resize->error != -EBUSY))
1449                 return;
1450
1451         mutex_lock(&kvm->lock);
1452
1453         /* Request is still current? */
1454         if (kvm->arch.resize_hpt == resize) {
1455                 /* We may request large allocations here:
1456                  * do not sleep with kvm->lock held for a while.
1457                  */
1458                 mutex_unlock(&kvm->lock);
1459
1460                 resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n",
1461                                  resize->order);
1462
1463                 err = resize_hpt_allocate(resize);
1464
1465                 /* We have strict assumption about -EBUSY
1466                  * when preparing for HPT resize.
1467                  */
1468                 if (WARN_ON(err == -EBUSY))
1469                         err = -EINPROGRESS;
1470
1471                 mutex_lock(&kvm->lock);
1472                 /* It is possible that kvm->arch.resize_hpt != resize
1473                  * after we grab kvm->lock again.
1474                  */
1475         }
1476
1477         resize->error = err;
1478
1479         if (kvm->arch.resize_hpt != resize)
1480                 resize_hpt_release(kvm, resize);
1481
1482         mutex_unlock(&kvm->lock);
1483 }
1484
1485 long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
1486                                      struct kvm_ppc_resize_hpt *rhpt)
1487 {
1488         unsigned long flags = rhpt->flags;
1489         unsigned long shift = rhpt->shift;
1490         struct kvm_resize_hpt *resize;
1491         int ret;
1492
1493         if (flags != 0 || kvm_is_radix(kvm))
1494                 return -EINVAL;
1495
1496         if (shift && ((shift < 18) || (shift > 46)))
1497                 return -EINVAL;
1498
1499         mutex_lock(&kvm->lock);
1500
1501         resize = kvm->arch.resize_hpt;
1502
1503         if (resize) {
1504                 if (resize->order == shift) {
1505                         /* Suitable resize in progress? */
1506                         ret = resize->error;
1507                         if (ret == -EBUSY)
1508                                 ret = 100; /* estimated time in ms */
1509                         else if (ret)
1510                                 resize_hpt_release(kvm, resize);
1511
1512                         goto out;
1513                 }
1514
1515                 /* not suitable, cancel it */
1516                 resize_hpt_release(kvm, resize);
1517         }
1518
1519         ret = 0;
1520         if (!shift)
1521                 goto out; /* nothing to do */
1522
1523         /* start new resize */
1524
1525         resize = kzalloc(sizeof(*resize), GFP_KERNEL);
1526         if (!resize) {
1527                 ret = -ENOMEM;
1528                 goto out;
1529         }
1530
1531         resize->error = -EBUSY;
1532         resize->order = shift;
1533         resize->kvm = kvm;
1534         INIT_WORK(&resize->work, resize_hpt_prepare_work);
1535         kvm->arch.resize_hpt = resize;
1536
1537         schedule_work(&resize->work);
1538
1539         ret = 100; /* estimated time in ms */
1540
1541 out:
1542         mutex_unlock(&kvm->lock);
1543         return ret;
1544 }
1545
1546 static void resize_hpt_boot_vcpu(void *opaque)
1547 {
1548         /* Nothing to do, just force a KVM exit */
1549 }
1550
1551 long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
1552                                     struct kvm_ppc_resize_hpt *rhpt)
1553 {
1554         unsigned long flags = rhpt->flags;
1555         unsigned long shift = rhpt->shift;
1556         struct kvm_resize_hpt *resize;
1557         long ret;
1558
1559         if (flags != 0 || kvm_is_radix(kvm))
1560                 return -EINVAL;
1561
1562         if (shift && ((shift < 18) || (shift > 46)))
1563                 return -EINVAL;
1564
1565         mutex_lock(&kvm->lock);
1566
1567         resize = kvm->arch.resize_hpt;
1568
1569         /* This shouldn't be possible */
1570         ret = -EIO;
1571         if (WARN_ON(!kvm->arch.mmu_ready))
1572                 goto out_no_hpt;
1573
1574         /* Stop VCPUs from running while we mess with the HPT */
1575         kvm->arch.mmu_ready = 0;
1576         smp_mb();
1577
1578         /* Boot all CPUs out of the guest so they re-read
1579          * mmu_ready */
1580         on_each_cpu(resize_hpt_boot_vcpu, NULL, 1);
1581
1582         ret = -ENXIO;
1583         if (!resize || (resize->order != shift))
1584                 goto out;
1585
1586         ret = resize->error;
1587         if (ret)
1588                 goto out;
1589
1590         ret = resize_hpt_rehash(resize);
1591         if (ret)
1592                 goto out;
1593
1594         resize_hpt_pivot(resize);
1595
1596 out:
1597         /* Let VCPUs run again */
1598         kvm->arch.mmu_ready = 1;
1599         smp_mb();
1600 out_no_hpt:
1601         resize_hpt_release(kvm, resize);
1602         mutex_unlock(&kvm->lock);
1603         return ret;
1604 }
1605
1606 /*
1607  * Functions for reading and writing the hash table via reads and
1608  * writes on a file descriptor.
1609  *
1610  * Reads return the guest view of the hash table, which has to be
1611  * pieced together from the real hash table and the guest_rpte
1612  * values in the revmap array.
1613  *
1614  * On writes, each HPTE written is considered in turn, and if it
1615  * is valid, it is written to the HPT as if an H_ENTER with the
1616  * exact flag set was done.  When the invalid count is non-zero
1617  * in the header written to the stream, the kernel will make
1618  * sure that that many HPTEs are invalid, and invalidate them
1619  * if not.
1620  */
1621
1622 struct kvm_htab_ctx {
1623         unsigned long   index;
1624         unsigned long   flags;
1625         struct kvm      *kvm;
1626         int             first_pass;
1627 };
1628
1629 #define HPTE_SIZE       (2 * sizeof(unsigned long))
1630
1631 /*
1632  * Returns 1 if this HPT entry has been modified or has pending
1633  * R/C bit changes.
1634  */
1635 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp)
1636 {
1637         unsigned long rcbits_unset;
1638
1639         if (revp->guest_rpte & HPTE_GR_MODIFIED)
1640                 return 1;
1641
1642         /* Also need to consider changes in reference and changed bits */
1643         rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1644         if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) &&
1645             (be64_to_cpu(hptp[1]) & rcbits_unset))
1646                 return 1;
1647
1648         return 0;
1649 }
1650
1651 static long record_hpte(unsigned long flags, __be64 *hptp,
1652                         unsigned long *hpte, struct revmap_entry *revp,
1653                         int want_valid, int first_pass)
1654 {
1655         unsigned long v, r, hr;
1656         unsigned long rcbits_unset;
1657         int ok = 1;
1658         int valid, dirty;
1659
1660         /* Unmodified entries are uninteresting except on the first pass */
1661         dirty = hpte_dirty(revp, hptp);
1662         if (!first_pass && !dirty)
1663                 return 0;
1664
1665         valid = 0;
1666         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1667                 valid = 1;
1668                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1669                     !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED))
1670                         valid = 0;
1671         }
1672         if (valid != want_valid)
1673                 return 0;
1674
1675         v = r = 0;
1676         if (valid || dirty) {
1677                 /* lock the HPTE so it's stable and read it */
1678                 preempt_disable();
1679                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1680                         cpu_relax();
1681                 v = be64_to_cpu(hptp[0]);
1682                 hr = be64_to_cpu(hptp[1]);
1683                 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1684                         v = hpte_new_to_old_v(v, hr);
1685                         hr = hpte_new_to_old_r(hr);
1686                 }
1687
1688                 /* re-evaluate valid and dirty from synchronized HPTE value */
1689                 valid = !!(v & HPTE_V_VALID);
1690                 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1691
1692                 /* Harvest R and C into guest view if necessary */
1693                 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1694                 if (valid && (rcbits_unset & hr)) {
1695                         revp->guest_rpte |= (hr &
1696                                 (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED;
1697                         dirty = 1;
1698                 }
1699
1700                 if (v & HPTE_V_ABSENT) {
1701                         v &= ~HPTE_V_ABSENT;
1702                         v |= HPTE_V_VALID;
1703                         valid = 1;
1704                 }
1705                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1706                         valid = 0;
1707
1708                 r = revp->guest_rpte;
1709                 /* only clear modified if this is the right sort of entry */
1710                 if (valid == want_valid && dirty) {
1711                         r &= ~HPTE_GR_MODIFIED;
1712                         revp->guest_rpte = r;
1713                 }
1714                 unlock_hpte(hptp, be64_to_cpu(hptp[0]));
1715                 preempt_enable();
1716                 if (!(valid == want_valid && (first_pass || dirty)))
1717                         ok = 0;
1718         }
1719         hpte[0] = cpu_to_be64(v);
1720         hpte[1] = cpu_to_be64(r);
1721         return ok;
1722 }
1723
1724 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1725                              size_t count, loff_t *ppos)
1726 {
1727         struct kvm_htab_ctx *ctx = file->private_data;
1728         struct kvm *kvm = ctx->kvm;
1729         struct kvm_get_htab_header hdr;
1730         __be64 *hptp;
1731         struct revmap_entry *revp;
1732         unsigned long i, nb, nw;
1733         unsigned long __user *lbuf;
1734         struct kvm_get_htab_header __user *hptr;
1735         unsigned long flags;
1736         int first_pass;
1737         unsigned long hpte[2];
1738
1739         if (!access_ok(VERIFY_WRITE, buf, count))
1740                 return -EFAULT;
1741         if (kvm_is_radix(kvm))
1742                 return 0;
1743
1744         first_pass = ctx->first_pass;
1745         flags = ctx->flags;
1746
1747         i = ctx->index;
1748         hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1749         revp = kvm->arch.hpt.rev + i;
1750         lbuf = (unsigned long __user *)buf;
1751
1752         nb = 0;
1753         while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1754                 /* Initialize header */
1755                 hptr = (struct kvm_get_htab_header __user *)buf;
1756                 hdr.n_valid = 0;
1757                 hdr.n_invalid = 0;
1758                 nw = nb;
1759                 nb += sizeof(hdr);
1760                 lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1761
1762                 /* Skip uninteresting entries, i.e. clean on not-first pass */
1763                 if (!first_pass) {
1764                         while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1765                                !hpte_dirty(revp, hptp)) {
1766                                 ++i;
1767                                 hptp += 2;
1768                                 ++revp;
1769                         }
1770                 }
1771                 hdr.index = i;
1772
1773                 /* Grab a series of valid entries */
1774                 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1775                        hdr.n_valid < 0xffff &&
1776                        nb + HPTE_SIZE < count &&
1777                        record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1778                         /* valid entry, write it out */
1779                         ++hdr.n_valid;
1780                         if (__put_user(hpte[0], lbuf) ||
1781                             __put_user(hpte[1], lbuf + 1))
1782                                 return -EFAULT;
1783                         nb += HPTE_SIZE;
1784                         lbuf += 2;
1785                         ++i;
1786                         hptp += 2;
1787                         ++revp;
1788                 }
1789                 /* Now skip invalid entries while we can */
1790                 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1791                        hdr.n_invalid < 0xffff &&
1792                        record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1793                         /* found an invalid entry */
1794                         ++hdr.n_invalid;
1795                         ++i;
1796                         hptp += 2;
1797                         ++revp;
1798                 }
1799
1800                 if (hdr.n_valid || hdr.n_invalid) {
1801                         /* write back the header */
1802                         if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1803                                 return -EFAULT;
1804                         nw = nb;
1805                         buf = (char __user *)lbuf;
1806                 } else {
1807                         nb = nw;
1808                 }
1809
1810                 /* Check if we've wrapped around the hash table */
1811                 if (i >= kvmppc_hpt_npte(&kvm->arch.hpt)) {
1812                         i = 0;
1813                         ctx->first_pass = 0;
1814                         break;
1815                 }
1816         }
1817
1818         ctx->index = i;
1819
1820         return nb;
1821 }
1822
1823 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1824                               size_t count, loff_t *ppos)
1825 {
1826         struct kvm_htab_ctx *ctx = file->private_data;
1827         struct kvm *kvm = ctx->kvm;
1828         struct kvm_get_htab_header hdr;
1829         unsigned long i, j;
1830         unsigned long v, r;
1831         unsigned long __user *lbuf;
1832         __be64 *hptp;
1833         unsigned long tmp[2];
1834         ssize_t nb;
1835         long int err, ret;
1836         int mmu_ready;
1837         int pshift;
1838
1839         if (!access_ok(VERIFY_READ, buf, count))
1840                 return -EFAULT;
1841         if (kvm_is_radix(kvm))
1842                 return -EINVAL;
1843
1844         /* lock out vcpus from running while we're doing this */
1845         mutex_lock(&kvm->lock);
1846         mmu_ready = kvm->arch.mmu_ready;
1847         if (mmu_ready) {
1848                 kvm->arch.mmu_ready = 0;        /* temporarily */
1849                 /* order mmu_ready vs. vcpus_running */
1850                 smp_mb();
1851                 if (atomic_read(&kvm->arch.vcpus_running)) {
1852                         kvm->arch.mmu_ready = 1;
1853                         mutex_unlock(&kvm->lock);
1854                         return -EBUSY;
1855                 }
1856         }
1857
1858         err = 0;
1859         for (nb = 0; nb + sizeof(hdr) <= count; ) {
1860                 err = -EFAULT;
1861                 if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1862                         break;
1863
1864                 err = 0;
1865                 if (nb + hdr.n_valid * HPTE_SIZE > count)
1866                         break;
1867
1868                 nb += sizeof(hdr);
1869                 buf += sizeof(hdr);
1870
1871                 err = -EINVAL;
1872                 i = hdr.index;
1873                 if (i >= kvmppc_hpt_npte(&kvm->arch.hpt) ||
1874                     i + hdr.n_valid + hdr.n_invalid > kvmppc_hpt_npte(&kvm->arch.hpt))
1875                         break;
1876
1877                 hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1878                 lbuf = (unsigned long __user *)buf;
1879                 for (j = 0; j < hdr.n_valid; ++j) {
1880                         __be64 hpte_v;
1881                         __be64 hpte_r;
1882
1883                         err = -EFAULT;
1884                         if (__get_user(hpte_v, lbuf) ||
1885                             __get_user(hpte_r, lbuf + 1))
1886                                 goto out;
1887                         v = be64_to_cpu(hpte_v);
1888                         r = be64_to_cpu(hpte_r);
1889                         err = -EINVAL;
1890                         if (!(v & HPTE_V_VALID))
1891                                 goto out;
1892                         pshift = kvmppc_hpte_base_page_shift(v, r);
1893                         if (pshift <= 0)
1894                                 goto out;
1895                         lbuf += 2;
1896                         nb += HPTE_SIZE;
1897
1898                         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1899                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1900                         err = -EIO;
1901                         ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1902                                                          tmp);
1903                         if (ret != H_SUCCESS) {
1904                                 pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
1905                                        "r=%lx\n", ret, i, v, r);
1906                                 goto out;
1907                         }
1908                         if (!mmu_ready && is_vrma_hpte(v)) {
1909                                 unsigned long senc, lpcr;
1910
1911                                 senc = slb_pgsize_encoding(1ul << pshift);
1912                                 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1913                                         (VRMA_VSID << SLB_VSID_SHIFT_1T);
1914                                 if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
1915                                         lpcr = senc << (LPCR_VRMASD_SH - 4);
1916                                         kvmppc_update_lpcr(kvm, lpcr,
1917                                                            LPCR_VRMASD);
1918                                 } else {
1919                                         kvmppc_setup_partition_table(kvm);
1920                                 }
1921                                 mmu_ready = 1;
1922                         }
1923                         ++i;
1924                         hptp += 2;
1925                 }
1926
1927                 for (j = 0; j < hdr.n_invalid; ++j) {
1928                         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1929                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1930                         ++i;
1931                         hptp += 2;
1932                 }
1933                 err = 0;
1934         }
1935
1936  out:
1937         /* Order HPTE updates vs. mmu_ready */
1938         smp_wmb();
1939         kvm->arch.mmu_ready = mmu_ready;
1940         mutex_unlock(&kvm->lock);
1941
1942         if (err)
1943                 return err;
1944         return nb;
1945 }
1946
1947 static int kvm_htab_release(struct inode *inode, struct file *filp)
1948 {
1949         struct kvm_htab_ctx *ctx = filp->private_data;
1950
1951         filp->private_data = NULL;
1952         if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1953                 atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1954         kvm_put_kvm(ctx->kvm);
1955         kfree(ctx);
1956         return 0;
1957 }
1958
1959 static const struct file_operations kvm_htab_fops = {
1960         .read           = kvm_htab_read,
1961         .write          = kvm_htab_write,
1962         .llseek         = default_llseek,
1963         .release        = kvm_htab_release,
1964 };
1965
1966 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1967 {
1968         int ret;
1969         struct kvm_htab_ctx *ctx;
1970         int rwflag;
1971
1972         /* reject flags we don't recognize */
1973         if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1974                 return -EINVAL;
1975         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1976         if (!ctx)
1977                 return -ENOMEM;
1978         kvm_get_kvm(kvm);
1979         ctx->kvm = kvm;
1980         ctx->index = ghf->start_index;
1981         ctx->flags = ghf->flags;
1982         ctx->first_pass = 1;
1983
1984         rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1985         ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
1986         if (ret < 0) {
1987                 kfree(ctx);
1988                 kvm_put_kvm(kvm);
1989                 return ret;
1990         }
1991
1992         if (rwflag == O_RDONLY) {
1993                 mutex_lock(&kvm->slots_lock);
1994                 atomic_inc(&kvm->arch.hpte_mod_interest);
1995                 /* make sure kvmppc_do_h_enter etc. see the increment */
1996                 synchronize_srcu_expedited(&kvm->srcu);
1997                 mutex_unlock(&kvm->slots_lock);
1998         }
1999
2000         return ret;
2001 }
2002
2003 struct debugfs_htab_state {
2004         struct kvm      *kvm;
2005         struct mutex    mutex;
2006         unsigned long   hpt_index;
2007         int             chars_left;
2008         int             buf_index;
2009         char            buf[64];
2010 };
2011
2012 static int debugfs_htab_open(struct inode *inode, struct file *file)
2013 {
2014         struct kvm *kvm = inode->i_private;
2015         struct debugfs_htab_state *p;
2016
2017         p = kzalloc(sizeof(*p), GFP_KERNEL);
2018         if (!p)
2019                 return -ENOMEM;
2020
2021         kvm_get_kvm(kvm);
2022         p->kvm = kvm;
2023         mutex_init(&p->mutex);
2024         file->private_data = p;
2025
2026         return nonseekable_open(inode, file);
2027 }
2028
2029 static int debugfs_htab_release(struct inode *inode, struct file *file)
2030 {
2031         struct debugfs_htab_state *p = file->private_data;
2032
2033         kvm_put_kvm(p->kvm);
2034         kfree(p);
2035         return 0;
2036 }
2037
2038 static ssize_t debugfs_htab_read(struct file *file, char __user *buf,
2039                                  size_t len, loff_t *ppos)
2040 {
2041         struct debugfs_htab_state *p = file->private_data;
2042         ssize_t ret, r;
2043         unsigned long i, n;
2044         unsigned long v, hr, gr;
2045         struct kvm *kvm;
2046         __be64 *hptp;
2047
2048         kvm = p->kvm;
2049         if (kvm_is_radix(kvm))
2050                 return 0;
2051
2052         ret = mutex_lock_interruptible(&p->mutex);
2053         if (ret)
2054                 return ret;
2055
2056         if (p->chars_left) {
2057                 n = p->chars_left;
2058                 if (n > len)
2059                         n = len;
2060                 r = copy_to_user(buf, p->buf + p->buf_index, n);
2061                 n -= r;
2062                 p->chars_left -= n;
2063                 p->buf_index += n;
2064                 buf += n;
2065                 len -= n;
2066                 ret = n;
2067                 if (r) {
2068                         if (!n)
2069                                 ret = -EFAULT;
2070                         goto out;
2071                 }
2072         }
2073
2074         i = p->hpt_index;
2075         hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
2076         for (; len != 0 && i < kvmppc_hpt_npte(&kvm->arch.hpt);
2077              ++i, hptp += 2) {
2078                 if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)))
2079                         continue;
2080
2081                 /* lock the HPTE so it's stable and read it */
2082                 preempt_disable();
2083                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
2084                         cpu_relax();
2085                 v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK;
2086                 hr = be64_to_cpu(hptp[1]);
2087                 gr = kvm->arch.hpt.rev[i].guest_rpte;
2088                 unlock_hpte(hptp, v);
2089                 preempt_enable();
2090
2091                 if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
2092                         continue;
2093
2094                 n = scnprintf(p->buf, sizeof(p->buf),
2095                               "%6lx %.16lx %.16lx %.16lx\n",
2096                               i, v, hr, gr);
2097                 p->chars_left = n;
2098                 if (n > len)
2099                         n = len;
2100                 r = copy_to_user(buf, p->buf, n);
2101                 n -= r;
2102                 p->chars_left -= n;
2103                 p->buf_index = n;
2104                 buf += n;
2105                 len -= n;
2106                 ret += n;
2107                 if (r) {
2108                         if (!ret)
2109                                 ret = -EFAULT;
2110                         goto out;
2111                 }
2112         }
2113         p->hpt_index = i;
2114
2115  out:
2116         mutex_unlock(&p->mutex);
2117         return ret;
2118 }
2119
2120 static ssize_t debugfs_htab_write(struct file *file, const char __user *buf,
2121                            size_t len, loff_t *ppos)
2122 {
2123         return -EACCES;
2124 }
2125
2126 static const struct file_operations debugfs_htab_fops = {
2127         .owner   = THIS_MODULE,
2128         .open    = debugfs_htab_open,
2129         .release = debugfs_htab_release,
2130         .read    = debugfs_htab_read,
2131         .write   = debugfs_htab_write,
2132         .llseek  = generic_file_llseek,
2133 };
2134
2135 void kvmppc_mmu_debugfs_init(struct kvm *kvm)
2136 {
2137         kvm->arch.htab_dentry = debugfs_create_file("htab", 0400,
2138                                                     kvm->arch.debugfs_dir, kvm,
2139                                                     &debugfs_htab_fops);
2140 }
2141
2142 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
2143 {
2144         struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
2145
2146         vcpu->arch.slb_nr = 32;         /* POWER7/POWER8 */
2147
2148         mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
2149         mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
2150
2151         vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
2152 }