arch/powerpc/kvm/book3s_64_mmu_hv.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *
   4  * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
   5  */
   6
   7 #include <linux/types.h>
   8 #include <linux/string.h>
   9 #include <linux/kvm.h>
  10 #include <linux/kvm_host.h>
  11 #include <linux/highmem.h>
  12 #include <linux/gfp.h>
  13 #include <linux/slab.h>
  14 #include <linux/hugetlb.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/srcu.h>
  17 #include <linux/anon_inodes.h>
  18 #include <linux/file.h>
  19 #include <linux/debugfs.h>
  20
  21 #include <asm/kvm_ppc.h>
  22 #include <asm/kvm_book3s.h>
  23 #include <asm/book3s/64/mmu-hash.h>
  24 #include <asm/hvcall.h>
  25 #include <asm/synch.h>
  26 #include <asm/ppc-opcode.h>
  27 #include <asm/cputable.h>
  28 #include <asm/pte-walk.h>
  29
  30 #include "book3s.h"
  31 #include "trace_hv.h"
  32
  33 //#define DEBUG_RESIZE_HPT      1
  34
  35 #ifdef DEBUG_RESIZE_HPT
  36 #define resize_hpt_debug(resize, ...)                           \
  37         do {                                                    \
  38                 printk(KERN_DEBUG "RESIZE HPT %p: ", resize);   \
  39                 printk(__VA_ARGS__);                            \
  40         } while (0)
  41 #else
  42 #define resize_hpt_debug(resize, ...)                           \
  43         do { } while (0)
  44 #endif
  45
  46 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
  47                                 long pte_index, unsigned long pteh,
  48                                 unsigned long ptel, unsigned long *pte_idx_ret);
  49
  50 struct kvm_resize_hpt {
  51         /* These fields read-only after init */
  52         struct kvm *kvm;
  53         struct work_struct work;
  54         u32 order;
  55
  56         /* These fields protected by kvm->arch.mmu_setup_lock */
  57
  58         /* Possible values and their usage:
  59          *  <0     an error occurred during allocation,
  60          *  -EBUSY allocation is in the progress,
  61          *  0      allocation made successfully.
  62          */
  63         int error;
  64
  65         /* Private to the work thread, until error != -EBUSY,
  66          * then protected by kvm->arch.mmu_setup_lock.
  67          */
  68         struct kvm_hpt_info hpt;
  69 };
  70
  71 int kvmppc_allocate_hpt(struct kvm_hpt_info *info, u32 order)
  72 {
  73         unsigned long hpt = 0;
  74         int cma = 0;
  75         struct page *page = NULL;
  76         struct revmap_entry *rev;
  77         unsigned long npte;
  78
  79         if ((order < PPC_MIN_HPT_ORDER) || (order > PPC_MAX_HPT_ORDER))
  80                 return -EINVAL;
  81
  82         page = kvm_alloc_hpt_cma(1ul << (order - PAGE_SHIFT));
  83         if (page) {
  84                 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
  85                 memset((void *)hpt, 0, (1ul << order));
  86                 cma = 1;
  87         }
  88
  89         if (!hpt)
  90                 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_RETRY_MAYFAIL
  91                                        |__GFP_NOWARN, order - PAGE_SHIFT);
  92
  93         if (!hpt)
  94                 return -ENOMEM;
  95
  96         /* HPTEs are 2**4 bytes long */
  97         npte = 1ul << (order - 4);
  98
  99         /* Allocate reverse map array */
 100         rev = vmalloc(array_size(npte, sizeof(struct revmap_entry)));
 101         if (!rev) {
 102                 if (cma)
 103                         kvm_free_hpt_cma(page, 1 << (order - PAGE_SHIFT));
 104                 else
 105                         free_pages(hpt, order - PAGE_SHIFT);
 106                 return -ENOMEM;
 107         }
 108
 109         info->order = order;
 110         info->virt = hpt;
 111         info->cma = cma;
 112         info->rev = rev;
 113
 114         return 0;
 115 }
 116
 117 void kvmppc_set_hpt(struct kvm *kvm, struct kvm_hpt_info *info)
 118 {
 119         atomic64_set(&kvm->arch.mmio_update, 0);
 120         kvm->arch.hpt = *info;
 121         kvm->arch.sdr1 = __pa(info->virt) | (info->order - 18);
 122
 123         pr_debug("KVM guest htab at %lx (order %ld), LPID %x\n",
 124                  info->virt, (long)info->order, kvm->arch.lpid);
 125 }
 126
 127 long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
 128 {
 129         long err = -EBUSY;
 130         struct kvm_hpt_info info;
 131
 132         mutex_lock(&kvm->arch.mmu_setup_lock);
 133         if (kvm->arch.mmu_ready) {
 134                 kvm->arch.mmu_ready = 0;
 135                 /* order mmu_ready vs. vcpus_running */
 136                 smp_mb();
 137                 if (atomic_read(&kvm->arch.vcpus_running)) {
 138                         kvm->arch.mmu_ready = 1;
 139                         goto out;
 140                 }
 141         }
 142         if (kvm_is_radix(kvm)) {
 143                 err = kvmppc_switch_mmu_to_hpt(kvm);
 144                 if (err)
 145                         goto out;
 146         }
 147
 148         if (kvm->arch.hpt.order == order) {
 149                 /* We already have a suitable HPT */
 150
 151                 /* Set the entire HPT to 0, i.e. invalid HPTEs */
 152                 memset((void *)kvm->arch.hpt.virt, 0, 1ul << order);
 153                 /*
 154                  * Reset all the reverse-mapping chains for all memslots
 155                  */
 156                 kvmppc_rmap_reset(kvm);
 157                 err = 0;
 158                 goto out;
 159         }
 160
 161         if (kvm->arch.hpt.virt) {
 162                 kvmppc_free_hpt(&kvm->arch.hpt);
 163                 kvmppc_rmap_reset(kvm);
 164         }
 165
 166         err = kvmppc_allocate_hpt(&info, order);
 167         if (err < 0)
 168                 goto out;
 169         kvmppc_set_hpt(kvm, &info);
 170
 171 out:
 172         if (err == 0)
 173                 /* Ensure that each vcpu will flush its TLB on next entry. */
 174                 cpumask_setall(&kvm->arch.need_tlb_flush);
 175
 176         mutex_unlock(&kvm->arch.mmu_setup_lock);
 177         return err;
 178 }
 179
 180 void kvmppc_free_hpt(struct kvm_hpt_info *info)
 181 {
 182         vfree(info->rev);
 183         info->rev = NULL;
 184         if (info->cma)
 185                 kvm_free_hpt_cma(virt_to_page(info->virt),
 186                                  1 << (info->order - PAGE_SHIFT));
 187         else if (info->virt)
 188                 free_pages(info->virt, info->order - PAGE_SHIFT);
 189         info->virt = 0;
 190         info->order = 0;
 191 }
 192
 193 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
 194 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
 195 {
 196         return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
 197 }
 198
 199 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
 200 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
 201 {
 202         return (pgsize == 0x10000) ? 0x1000 : 0;
 203 }
 204
 205 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
 206                      unsigned long porder)
 207 {
 208         unsigned long i;
 209         unsigned long npages;
 210         unsigned long hp_v, hp_r;
 211         unsigned long addr, hash;
 212         unsigned long psize;
 213         unsigned long hp0, hp1;
 214         unsigned long idx_ret;
 215         long ret;
 216         struct kvm *kvm = vcpu->kvm;
 217
 218         psize = 1ul << porder;
 219         npages = memslot->npages >> (porder - PAGE_SHIFT);
 220
 221         /* VRMA can't be > 1TB */
 222         if (npages > 1ul << (40 - porder))
 223                 npages = 1ul << (40 - porder);
 224         /* Can't use more than 1 HPTE per HPTEG */
 225         if (npages > kvmppc_hpt_mask(&kvm->arch.hpt) + 1)
 226                 npages = kvmppc_hpt_mask(&kvm->arch.hpt) + 1;
 227
 228         hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
 229                 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
 230         hp1 = hpte1_pgsize_encoding(psize) |
 231                 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
 232
 233         for (i = 0; i < npages; ++i) {
 234                 addr = i << porder;
 235                 /* can't use hpt_hash since va > 64 bits */
 236                 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25)))
 237                         & kvmppc_hpt_mask(&kvm->arch.hpt);
 238                 /*
 239                  * We assume that the hash table is empty and no
 240                  * vcpus are using it at this stage.  Since we create
 241                  * at most one HPTE per HPTEG, we just assume entry 7
 242                  * is available and use it.
 243                  */
 244                 hash = (hash << 3) + 7;
 245                 hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
 246                 hp_r = hp1 | addr;
 247                 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
 248                                                  &idx_ret);
 249                 if (ret != H_SUCCESS) {
 250                         pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
 251                                addr, ret);
 252                         break;
 253                 }
 254         }
 255 }
 256
 257 int kvmppc_mmu_hv_init(void)
 258 {
 259         unsigned long nr_lpids;
 260
 261         if (!mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE))
 262                 return -EINVAL;
 263
 264         if (cpu_has_feature(CPU_FTR_HVMODE)) {
 265                 if (WARN_ON(mfspr(SPRN_LPID) != 0))
 266                         return -EINVAL;
 267                 nr_lpids = 1UL << mmu_lpid_bits;
 268         } else {
 269                 nr_lpids = 1UL << KVM_MAX_NESTED_GUESTS_SHIFT;
 270         }
 271
 272         if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
 273                 /* POWER7 has 10-bit LPIDs, POWER8 has 12-bit LPIDs */
 274                 if (cpu_has_feature(CPU_FTR_ARCH_207S))
 275                         WARN_ON(nr_lpids != 1UL << 12);
 276                 else
 277                         WARN_ON(nr_lpids != 1UL << 10);
 278
 279                 /*
 280                  * Reserve the last implemented LPID use in partition
 281                  * switching for POWER7 and POWER8.
 282                  */
 283                 nr_lpids -= 1;
 284         }
 285
 286         kvmppc_init_lpid(nr_lpids);
 287
 288         return 0;
 289 }
 290
 291 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
 292                                 long pte_index, unsigned long pteh,
 293                                 unsigned long ptel, unsigned long *pte_idx_ret)
 294 {
 295         long ret;
 296
 297         preempt_disable();
 298         ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
 299                                 kvm->mm->pgd, false, pte_idx_ret);
 300         preempt_enable();
 301         if (ret == H_TOO_HARD) {
 302                 /* this can't happen */
 303                 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
 304                 ret = H_RESOURCE;       /* or something */
 305         }
 306         return ret;
 307
 308 }
 309
 310 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
 311                                                          gva_t eaddr)
 312 {
 313         u64 mask;
 314         int i;
 315
 316         for (i = 0; i < vcpu->arch.slb_nr; i++) {
 317                 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
 318                         continue;
 319
 320                 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
 321                         mask = ESID_MASK_1T;
 322                 else
 323                         mask = ESID_MASK;
 324
 325                 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
 326                         return &vcpu->arch.slb[i];
 327         }
 328         return NULL;
 329 }
 330
 331 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
 332                         unsigned long ea)
 333 {
 334         unsigned long ra_mask;
 335
 336         ra_mask = kvmppc_actual_pgsz(v, r) - 1;
 337         return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
 338 }
 339
 340 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 341                         struct kvmppc_pte *gpte, bool data, bool iswrite)
 342 {
 343         struct kvm *kvm = vcpu->kvm;
 344         struct kvmppc_slb *slbe;
 345         unsigned long slb_v;
 346         unsigned long pp, key;
 347         unsigned long v, orig_v, gr;
 348         __be64 *hptep;
 349         long int index;
 350         int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
 351
 352         if (kvm_is_radix(vcpu->kvm))
 353                 return kvmppc_mmu_radix_xlate(vcpu, eaddr, gpte, data, iswrite);
 354
 355         /* Get SLB entry */
 356         if (virtmode) {
 357                 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
 358                 if (!slbe)
 359                         return -EINVAL;
 360                 slb_v = slbe->origv;
 361         } else {
 362                 /* real mode access */
 363                 slb_v = vcpu->kvm->arch.vrma_slb_v;
 364         }
 365
 366         preempt_disable();
 367         /* Find the HPTE in the hash table */
 368         index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
 369                                          HPTE_V_VALID | HPTE_V_ABSENT);
 370         if (index < 0) {
 371                 preempt_enable();
 372                 return -ENOENT;
 373         }
 374         hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
 375         v = orig_v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
 376         if (cpu_has_feature(CPU_FTR_ARCH_300))
 377                 v = hpte_new_to_old_v(v, be64_to_cpu(hptep[1]));
 378         gr = kvm->arch.hpt.rev[index].guest_rpte;
 379
 380         unlock_hpte(hptep, orig_v);
 381         preempt_enable();
 382
 383         gpte->eaddr = eaddr;
 384         gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
 385
 386         /* Get PP bits and key for permission check */
 387         pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
 388         key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
 389         key &= slb_v;
 390
 391         /* Calculate permissions */
 392         gpte->may_read = hpte_read_permission(pp, key);
 393         gpte->may_write = hpte_write_permission(pp, key);
 394         gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
 395
 396         /* Storage key permission check for POWER7 */
 397         if (data && virtmode) {
 398                 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
 399                 if (amrfield & 1)
 400                         gpte->may_read = 0;
 401                 if (amrfield & 2)
 402                         gpte->may_write = 0;
 403         }
 404
 405         /* Get the guest physical address */
 406         gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
 407         return 0;
 408 }
 409
 410 /*
 411  * Quick test for whether an instruction is a load or a store.
 412  * If the instruction is a load or a store, then this will indicate
 413  * which it is, at least on server processors.  (Embedded processors
 414  * have some external PID instructions that don't follow the rule
 415  * embodied here.)  If the instruction isn't a load or store, then
 416  * this doesn't return anything useful.
 417  */
 418 static int instruction_is_store(unsigned int instr)
 419 {
 420         unsigned int mask;
 421
 422         mask = 0x10000000;
 423         if ((instr & 0xfc000000) == 0x7c000000)
 424                 mask = 0x100;           /* major opcode 31 */
 425         return (instr & mask) != 0;
 426 }
 427
 428 int kvmppc_hv_emulate_mmio(struct kvm_vcpu *vcpu,
 429                            unsigned long gpa, gva_t ea, int is_store)
 430 {
 431         u32 last_inst;
 432
 433         /*
 434          * Fast path - check if the guest physical address corresponds to a
 435          * device on the FAST_MMIO_BUS, if so we can avoid loading the
 436          * instruction all together, then we can just handle it and return.
 437          */
 438         if (is_store) {
 439                 int idx, ret;
 440
 441                 idx = srcu_read_lock(&vcpu->kvm->srcu);
 442                 ret = kvm_io_bus_write(vcpu, KVM_FAST_MMIO_BUS, (gpa_t) gpa, 0,
 443                                        NULL);
 444                 srcu_read_unlock(&vcpu->kvm->srcu, idx);
 445                 if (!ret) {
 446                         kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 447                         return RESUME_GUEST;
 448                 }
 449         }
 450
 451         /*
 452          * If we fail, we just return to the guest and try executing it again.
 453          */
 454         if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
 455                 EMULATE_DONE)
 456                 return RESUME_GUEST;
 457
 458         /*
 459          * WARNING: We do not know for sure whether the instruction we just
 460          * read from memory is the same that caused the fault in the first
 461          * place.  If the instruction we read is neither an load or a store,
 462          * then it can't access memory, so we don't need to worry about
 463          * enforcing access permissions.  So, assuming it is a load or
 464          * store, we just check that its direction (load or store) is
 465          * consistent with the original fault, since that's what we
 466          * checked the access permissions against.  If there is a mismatch
 467          * we just return and retry the instruction.
 468          */
 469
 470         if (instruction_is_store(last_inst) != !!is_store)
 471                 return RESUME_GUEST;
 472
 473         /*
 474          * Emulated accesses are emulated by looking at the hash for
 475          * translation once, then performing the access later. The
 476          * translation could be invalidated in the meantime in which
 477          * point performing the subsequent memory access on the old
 478          * physical address could possibly be a security hole for the
 479          * guest (but not the host).
 480          *
 481          * This is less of an issue for MMIO stores since they aren't
 482          * globally visible. It could be an issue for MMIO loads to
 483          * a certain extent but we'll ignore it for now.
 484          */
 485
 486         vcpu->arch.paddr_accessed = gpa;
 487         vcpu->arch.vaddr_accessed = ea;
 488         return kvmppc_emulate_mmio(vcpu);
 489 }
 490
 491 int kvmppc_book3s_hv_page_fault(struct kvm_vcpu *vcpu,
 492                                 unsigned long ea, unsigned long dsisr)
 493 {
 494         struct kvm *kvm = vcpu->kvm;
 495         unsigned long hpte[3], r;
 496         unsigned long hnow_v, hnow_r;
 497         __be64 *hptep;
 498         unsigned long mmu_seq, psize, pte_size;
 499         unsigned long gpa_base, gfn_base;
 500         unsigned long gpa, gfn, hva, pfn, hpa;
 501         struct kvm_memory_slot *memslot;
 502         unsigned long *rmap;
 503         struct revmap_entry *rev;
 504         struct page *page;
 505         long index, ret;
 506         bool is_ci;
 507         bool writing, write_ok;
 508         unsigned int shift;
 509         unsigned long rcbits;
 510         long mmio_update;
 511         pte_t pte, *ptep;
 512
 513         if (kvm_is_radix(kvm))
 514                 return kvmppc_book3s_radix_page_fault(vcpu, ea, dsisr);
 515
 516         /*
 517          * Real-mode code has already searched the HPT and found the
 518          * entry we're interested in.  Lock the entry and check that
 519          * it hasn't changed.  If it has, just return and re-execute the
 520          * instruction.
 521          */
 522         if (ea != vcpu->arch.pgfault_addr)
 523                 return RESUME_GUEST;
 524
 525         if (vcpu->arch.pgfault_cache) {
 526                 mmio_update = atomic64_read(&kvm->arch.mmio_update);
 527                 if (mmio_update == vcpu->arch.pgfault_cache->mmio_update) {
 528                         r = vcpu->arch.pgfault_cache->rpte;
 529                         psize = kvmppc_actual_pgsz(vcpu->arch.pgfault_hpte[0],
 530                                                    r);
 531                         gpa_base = r & HPTE_R_RPN & ~(psize - 1);
 532                         gfn_base = gpa_base >> PAGE_SHIFT;
 533                         gpa = gpa_base | (ea & (psize - 1));
 534                         return kvmppc_hv_emulate_mmio(vcpu, gpa, ea,
 535                                                 dsisr & DSISR_ISSTORE);
 536                 }
 537         }
 538         index = vcpu->arch.pgfault_index;
 539         hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
 540         rev = &kvm->arch.hpt.rev[index];
 541         preempt_disable();
 542         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
 543                 cpu_relax();
 544         hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
 545         hpte[1] = be64_to_cpu(hptep[1]);
 546         hpte[2] = r = rev->guest_rpte;
 547         unlock_hpte(hptep, hpte[0]);
 548         preempt_enable();
 549
 550         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
 551                 hpte[0] = hpte_new_to_old_v(hpte[0], hpte[1]);
 552                 hpte[1] = hpte_new_to_old_r(hpte[1]);
 553         }
 554         if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
 555             hpte[1] != vcpu->arch.pgfault_hpte[1])
 556                 return RESUME_GUEST;
 557
 558         /* Translate the logical address and get the page */
 559         psize = kvmppc_actual_pgsz(hpte[0], r);
 560         gpa_base = r & HPTE_R_RPN & ~(psize - 1);
 561         gfn_base = gpa_base >> PAGE_SHIFT;
 562         gpa = gpa_base | (ea & (psize - 1));
 563         gfn = gpa >> PAGE_SHIFT;
 564         memslot = gfn_to_memslot(kvm, gfn);
 565
 566         trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr);
 567
 568         /* No memslot means it's an emulated MMIO region */
 569         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
 570                 return kvmppc_hv_emulate_mmio(vcpu, gpa, ea,
 571                                               dsisr & DSISR_ISSTORE);
 572
 573         /*
 574          * This should never happen, because of the slot_is_aligned()
 575          * check in kvmppc_do_h_enter().
 576          */
 577         if (gfn_base < memslot->base_gfn)
 578                 return -EFAULT;
 579
 580         /* used to check for invalidations in progress */
 581         mmu_seq = kvm->mmu_invalidate_seq;
 582         smp_rmb();
 583
 584         ret = -EFAULT;
 585         page = NULL;
 586         writing = (dsisr & DSISR_ISSTORE) != 0;
 587         /* If writing != 0, then the HPTE must allow writing, if we get here */
 588         write_ok = writing;
 589         hva = gfn_to_hva_memslot(memslot, gfn);
 590
 591         /*
 592          * Do a fast check first, since __gfn_to_pfn_memslot doesn't
 593          * do it with !atomic && !async, which is how we call it.
 594          * We always ask for write permission since the common case
 595          * is that the page is writable.
 596          */
 597         if (get_user_page_fast_only(hva, FOLL_WRITE, &page)) {
 598                 write_ok = true;
 599         } else {
 600                 /* Call KVM generic code to do the slow-path check */
 601                 pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL,
 602                                            writing, &write_ok, NULL);
 603                 if (is_error_noslot_pfn(pfn))
 604                         return -EFAULT;
 605                 page = NULL;
 606                 if (pfn_valid(pfn)) {
 607                         page = pfn_to_page(pfn);
 608                         if (PageReserved(page))
 609                                 page = NULL;
 610                 }
 611         }
 612
 613         /*
 614          * Read the PTE from the process' radix tree and use that
 615          * so we get the shift and attribute bits.
 616          */
 617         spin_lock(&kvm->mmu_lock);
 618         ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &shift);
 619         pte = __pte(0);
 620         if (ptep)
 621                 pte = READ_ONCE(*ptep);
 622         spin_unlock(&kvm->mmu_lock);
 623         /*
 624          * If the PTE disappeared temporarily due to a THP
 625          * collapse, just return and let the guest try again.
 626          */
 627         if (!pte_present(pte)) {
 628                 if (page)
 629                         put_page(page);
 630                 return RESUME_GUEST;
 631         }
 632         hpa = pte_pfn(pte) << PAGE_SHIFT;
 633         pte_size = PAGE_SIZE;
 634         if (shift)
 635                 pte_size = 1ul << shift;
 636         is_ci = pte_ci(pte);
 637
 638         if (psize > pte_size)
 639                 goto out_put;
 640         if (pte_size > psize)
 641                 hpa |= hva & (pte_size - psize);
 642
 643         /* Check WIMG vs. the actual page we're accessing */
 644         if (!hpte_cache_flags_ok(r, is_ci)) {
 645                 if (is_ci)
 646                         goto out_put;
 647                 /*
 648                  * Allow guest to map emulated device memory as
 649                  * uncacheable, but actually make it cacheable.
 650                  */
 651                 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
 652         }
 653
 654         /*
 655          * Set the HPTE to point to hpa.
 656          * Since the hpa is at PAGE_SIZE granularity, make sure we
 657          * don't mask out lower-order bits if psize < PAGE_SIZE.
 658          */
 659         if (psize < PAGE_SIZE)
 660                 psize = PAGE_SIZE;
 661         r = (r & HPTE_R_KEY_HI) | (r & ~(HPTE_R_PP0 - psize)) | hpa;
 662         if (hpte_is_writable(r) && !write_ok)
 663                 r = hpte_make_readonly(r);
 664         ret = RESUME_GUEST;
 665         preempt_disable();
 666         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
 667                 cpu_relax();
 668         hnow_v = be64_to_cpu(hptep[0]);
 669         hnow_r = be64_to_cpu(hptep[1]);
 670         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
 671                 hnow_v = hpte_new_to_old_v(hnow_v, hnow_r);
 672                 hnow_r = hpte_new_to_old_r(hnow_r);
 673         }
 674
 675         /*
 676          * If the HPT is being resized, don't update the HPTE,
 677          * instead let the guest retry after the resize operation is complete.
 678          * The synchronization for mmu_ready test vs. set is provided
 679          * by the HPTE lock.
 680          */
 681         if (!kvm->arch.mmu_ready)
 682                 goto out_unlock;
 683
 684         if ((hnow_v & ~HPTE_V_HVLOCK) != hpte[0] || hnow_r != hpte[1] ||
 685             rev->guest_rpte != hpte[2])
 686                 /* HPTE has been changed under us; let the guest retry */
 687                 goto out_unlock;
 688         hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
 689
 690         /* Always put the HPTE in the rmap chain for the page base address */
 691         rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn];
 692         lock_rmap(rmap);
 693
 694         /* Check if we might have been invalidated; let the guest retry if so */
 695         ret = RESUME_GUEST;
 696         if (mmu_invalidate_retry(vcpu->kvm, mmu_seq)) {
 697                 unlock_rmap(rmap);
 698                 goto out_unlock;
 699         }
 700
 701         /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
 702         rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
 703         r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
 704
 705         if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) {
 706                 /* HPTE was previously valid, so we need to invalidate it */
 707                 unlock_rmap(rmap);
 708                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
 709                 kvmppc_invalidate_hpte(kvm, hptep, index);
 710                 /* don't lose previous R and C bits */
 711                 r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
 712         } else {
 713                 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
 714         }
 715
 716         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
 717                 r = hpte_old_to_new_r(hpte[0], r);
 718                 hpte[0] = hpte_old_to_new_v(hpte[0]);
 719         }
 720         hptep[1] = cpu_to_be64(r);
 721         eieio();
 722         __unlock_hpte(hptep, hpte[0]);
 723         asm volatile("ptesync" : : : "memory");
 724         preempt_enable();
 725         if (page && hpte_is_writable(r))
 726                 set_page_dirty_lock(page);
 727
 728  out_put:
 729         trace_kvm_page_fault_exit(vcpu, hpte, ret);
 730
 731         if (page)
 732                 put_page(page);
 733         return ret;
 734
 735  out_unlock:
 736         __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
 737         preempt_enable();
 738         goto out_put;
 739 }
 740
 741 void kvmppc_rmap_reset(struct kvm *kvm)
 742 {
 743         struct kvm_memslots *slots;
 744         struct kvm_memory_slot *memslot;
 745         int srcu_idx, bkt;
 746
 747         srcu_idx = srcu_read_lock(&kvm->srcu);
 748         slots = kvm_memslots(kvm);
 749         kvm_for_each_memslot(memslot, bkt, slots) {
 750                 /* Mutual exclusion with kvm_unmap_hva_range etc. */
 751                 spin_lock(&kvm->mmu_lock);
 752                 /*
 753                  * This assumes it is acceptable to lose reference and
 754                  * change bits across a reset.
 755                  */
 756                 memset(memslot->arch.rmap, 0,
 757                        memslot->npages * sizeof(*memslot->arch.rmap));
 758                 spin_unlock(&kvm->mmu_lock);
 759         }
 760         srcu_read_unlock(&kvm->srcu, srcu_idx);
 761 }
 762
 763 /* Must be called with both HPTE and rmap locked */
 764 static void kvmppc_unmap_hpte(struct kvm *kvm, unsigned long i,
 765                               struct kvm_memory_slot *memslot,
 766                               unsigned long *rmapp, unsigned long gfn)
 767 {
 768         __be64 *hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
 769         struct revmap_entry *rev = kvm->arch.hpt.rev;
 770         unsigned long j, h;
 771         unsigned long ptel, psize, rcbits;
 772
 773         j = rev[i].forw;
 774         if (j == i) {
 775                 /* chain is now empty */
 776                 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
 777         } else {
 778                 /* remove i from chain */
 779                 h = rev[i].back;
 780                 rev[h].forw = j;
 781                 rev[j].back = h;
 782                 rev[i].forw = rev[i].back = i;
 783                 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
 784         }
 785
 786         /* Now check and modify the HPTE */
 787         ptel = rev[i].guest_rpte;
 788         psize = kvmppc_actual_pgsz(be64_to_cpu(hptep[0]), ptel);
 789         if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
 790             hpte_rpn(ptel, psize) == gfn) {
 791                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
 792                 kvmppc_invalidate_hpte(kvm, hptep, i);
 793                 hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
 794                 /* Harvest R and C */
 795                 rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
 796                 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
 797                 if ((rcbits & HPTE_R_C) && memslot->dirty_bitmap)
 798                         kvmppc_update_dirty_map(memslot, gfn, psize);
 799                 if (rcbits & ~rev[i].guest_rpte) {
 800                         rev[i].guest_rpte = ptel | rcbits;
 801                         note_hpte_modification(kvm, &rev[i]);
 802                 }
 803         }
 804 }
 805
 806 static void kvm_unmap_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
 807                             unsigned long gfn)
 808 {
 809         unsigned long i;
 810         __be64 *hptep;
 811         unsigned long *rmapp;
 812
 813         rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
 814         for (;;) {
 815                 lock_rmap(rmapp);
 816                 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 817                         unlock_rmap(rmapp);
 818                         break;
 819                 }
 820
 821                 /*
 822                  * To avoid an ABBA deadlock with the HPTE lock bit,
 823                  * we can't spin on the HPTE lock while holding the
 824                  * rmap chain lock.
 825                  */
 826                 i = *rmapp & KVMPPC_RMAP_INDEX;
 827                 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
 828                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 829                         /* unlock rmap before spinning on the HPTE lock */
 830                         unlock_rmap(rmapp);
 831                         while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
 832                                 cpu_relax();
 833                         continue;
 834                 }
 835
 836                 kvmppc_unmap_hpte(kvm, i, memslot, rmapp, gfn);
 837                 unlock_rmap(rmapp);
 838                 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
 839         }
 840 }
 841
 842 bool kvm_unmap_gfn_range_hv(struct kvm *kvm, struct kvm_gfn_range *range)
 843 {
 844         gfn_t gfn;
 845
 846         if (kvm_is_radix(kvm)) {
 847                 for (gfn = range->start; gfn < range->end; gfn++)
 848                         kvm_unmap_radix(kvm, range->slot, gfn);
 849         } else {
 850                 for (gfn = range->start; gfn < range->end; gfn++)
 851                         kvm_unmap_rmapp(kvm, range->slot, gfn);
 852         }
 853
 854         return false;
 855 }
 856
 857 void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
 858                                   struct kvm_memory_slot *memslot)
 859 {
 860         unsigned long gfn;
 861         unsigned long n;
 862         unsigned long *rmapp;
 863
 864         gfn = memslot->base_gfn;
 865         rmapp = memslot->arch.rmap;
 866         if (kvm_is_radix(kvm)) {
 867                 kvmppc_radix_flush_memslot(kvm, memslot);
 868                 return;
 869         }
 870
 871         for (n = memslot->npages; n; --n, ++gfn) {
 872                 /*
 873                  * Testing the present bit without locking is OK because
 874                  * the memslot has been marked invalid already, and hence
 875                  * no new HPTEs referencing this page can be created,
 876                  * thus the present bit can't go from 0 to 1.
 877                  */
 878                 if (*rmapp & KVMPPC_RMAP_PRESENT)
 879                         kvm_unmap_rmapp(kvm, memslot, gfn);
 880                 ++rmapp;
 881         }
 882 }
 883
 884 static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
 885                           unsigned long gfn)
 886 {
 887         struct revmap_entry *rev = kvm->arch.hpt.rev;
 888         unsigned long head, i, j;
 889         __be64 *hptep;
 890         bool ret = false;
 891         unsigned long *rmapp;
 892
 893         rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
 894  retry:
 895         lock_rmap(rmapp);
 896         if (*rmapp & KVMPPC_RMAP_REFERENCED) {
 897                 *rmapp &= ~KVMPPC_RMAP_REFERENCED;
 898                 ret = true;
 899         }
 900         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 901                 unlock_rmap(rmapp);
 902                 return ret;
 903         }
 904
 905         i = head = *rmapp & KVMPPC_RMAP_INDEX;
 906         do {
 907                 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
 908                 j = rev[i].forw;
 909
 910                 /* If this HPTE isn't referenced, ignore it */
 911                 if (!(be64_to_cpu(hptep[1]) & HPTE_R_R))
 912                         continue;
 913
 914                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 915                         /* unlock rmap before spinning on the HPTE lock */
 916                         unlock_rmap(rmapp);
 917                         while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
 918                                 cpu_relax();
 919                         goto retry;
 920                 }
 921
 922                 /* Now check and modify the HPTE */
 923                 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
 924                     (be64_to_cpu(hptep[1]) & HPTE_R_R)) {
 925                         kvmppc_clear_ref_hpte(kvm, hptep, i);
 926                         if (!(rev[i].guest_rpte & HPTE_R_R)) {
 927                                 rev[i].guest_rpte |= HPTE_R_R;
 928                                 note_hpte_modification(kvm, &rev[i]);
 929                         }
 930                         ret = true;
 931                 }
 932                 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
 933         } while ((i = j) != head);
 934
 935         unlock_rmap(rmapp);
 936         return ret;
 937 }
 938
 939 bool kvm_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range)
 940 {
 941         gfn_t gfn;
 942         bool ret = false;
 943
 944         if (kvm_is_radix(kvm)) {
 945                 for (gfn = range->start; gfn < range->end; gfn++)
 946                         ret |= kvm_age_radix(kvm, range->slot, gfn);
 947         } else {
 948                 for (gfn = range->start; gfn < range->end; gfn++)
 949                         ret |= kvm_age_rmapp(kvm, range->slot, gfn);
 950         }
 951
 952         return ret;
 953 }
 954
 955 static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
 956                                unsigned long gfn)
 957 {
 958         struct revmap_entry *rev = kvm->arch.hpt.rev;
 959         unsigned long head, i, j;
 960         unsigned long *hp;
 961         bool ret = true;
 962         unsigned long *rmapp;
 963
 964         rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
 965         if (*rmapp & KVMPPC_RMAP_REFERENCED)
 966                 return true;
 967
 968         lock_rmap(rmapp);
 969         if (*rmapp & KVMPPC_RMAP_REFERENCED)
 970                 goto out;
 971
 972         if (*rmapp & KVMPPC_RMAP_PRESENT) {
 973                 i = head = *rmapp & KVMPPC_RMAP_INDEX;
 974                 do {
 975                         hp = (unsigned long *)(kvm->arch.hpt.virt + (i << 4));
 976                         j = rev[i].forw;
 977                         if (be64_to_cpu(hp[1]) & HPTE_R_R)
 978                                 goto out;
 979                 } while ((i = j) != head);
 980         }
 981         ret = false;
 982
 983  out:
 984         unlock_rmap(rmapp);
 985         return ret;
 986 }
 987
 988 bool kvm_test_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range)
 989 {
 990         WARN_ON(range->start + 1 != range->end);
 991
 992         if (kvm_is_radix(kvm))
 993                 return kvm_test_age_radix(kvm, range->slot, range->start);
 994         else
 995                 return kvm_test_age_rmapp(kvm, range->slot, range->start);
 996 }
 997
 998 bool kvm_set_spte_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range)
 999 {
1000         WARN_ON(range->start + 1 != range->end);
1001
1002         if (kvm_is_radix(kvm))
1003                 kvm_unmap_radix(kvm, range->slot, range->start);
1004         else
1005                 kvm_unmap_rmapp(kvm, range->slot, range->start);
1006
1007         return false;
1008 }
1009
1010 static int vcpus_running(struct kvm *kvm)
1011 {
1012         return atomic_read(&kvm->arch.vcpus_running) != 0;
1013 }
1014
1015 /*
1016  * Returns the number of system pages that are dirty.
1017  * This can be more than 1 if we find a huge-page HPTE.
1018  */
1019 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
1020 {
1021         struct revmap_entry *rev = kvm->arch.hpt.rev;
1022         unsigned long head, i, j;
1023         unsigned long n;
1024         unsigned long v, r;
1025         __be64 *hptep;
1026         int npages_dirty = 0;
1027
1028  retry:
1029         lock_rmap(rmapp);
1030         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
1031                 unlock_rmap(rmapp);
1032                 return npages_dirty;
1033         }
1034
1035         i = head = *rmapp & KVMPPC_RMAP_INDEX;
1036         do {
1037                 unsigned long hptep1;
1038                 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
1039                 j = rev[i].forw;
1040
1041                 /*
1042                  * Checking the C (changed) bit here is racy since there
1043                  * is no guarantee about when the hardware writes it back.
1044                  * If the HPTE is not writable then it is stable since the
1045                  * page can't be written to, and we would have done a tlbie
1046                  * (which forces the hardware to complete any writeback)
1047                  * when making the HPTE read-only.
1048                  * If vcpus are running then this call is racy anyway
1049                  * since the page could get dirtied subsequently, so we
1050                  * expect there to be a further call which would pick up
1051                  * any delayed C bit writeback.
1052                  * Otherwise we need to do the tlbie even if C==0 in
1053                  * order to pick up any delayed writeback of C.
1054                  */
1055                 hptep1 = be64_to_cpu(hptep[1]);
1056                 if (!(hptep1 & HPTE_R_C) &&
1057                     (!hpte_is_writable(hptep1) || vcpus_running(kvm)))
1058                         continue;
1059
1060                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
1061                         /* unlock rmap before spinning on the HPTE lock */
1062                         unlock_rmap(rmapp);
1063                         while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK))
1064                                 cpu_relax();
1065                         goto retry;
1066                 }
1067
1068                 /* Now check and modify the HPTE */
1069                 if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) {
1070                         __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
1071                         continue;
1072                 }
1073
1074                 /* need to make it temporarily absent so C is stable */
1075                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
1076                 kvmppc_invalidate_hpte(kvm, hptep, i);
1077                 v = be64_to_cpu(hptep[0]);
1078                 r = be64_to_cpu(hptep[1]);
1079                 if (r & HPTE_R_C) {
1080                         hptep[1] = cpu_to_be64(r & ~HPTE_R_C);
1081                         if (!(rev[i].guest_rpte & HPTE_R_C)) {
1082                                 rev[i].guest_rpte |= HPTE_R_C;
1083                                 note_hpte_modification(kvm, &rev[i]);
1084                         }
1085                         n = kvmppc_actual_pgsz(v, r);
1086                         n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT;
1087                         if (n > npages_dirty)
1088                                 npages_dirty = n;
1089                         eieio();
1090                 }
1091                 v &= ~HPTE_V_ABSENT;
1092                 v |= HPTE_V_VALID;
1093                 __unlock_hpte(hptep, v);
1094         } while ((i = j) != head);
1095
1096         unlock_rmap(rmapp);
1097         return npages_dirty;
1098 }
1099
1100 void kvmppc_harvest_vpa_dirty(struct kvmppc_vpa *vpa,
1101                               struct kvm_memory_slot *memslot,
1102                               unsigned long *map)
1103 {
1104         unsigned long gfn;
1105
1106         if (!vpa->dirty || !vpa->pinned_addr)
1107                 return;
1108         gfn = vpa->gpa >> PAGE_SHIFT;
1109         if (gfn < memslot->base_gfn ||
1110             gfn >= memslot->base_gfn + memslot->npages)
1111                 return;
1112
1113         vpa->dirty = false;
1114         if (map)
1115                 __set_bit_le(gfn - memslot->base_gfn, map);
1116 }
1117
1118 long kvmppc_hv_get_dirty_log_hpt(struct kvm *kvm,
1119                         struct kvm_memory_slot *memslot, unsigned long *map)
1120 {
1121         unsigned long i;
1122         unsigned long *rmapp;
1123
1124         preempt_disable();
1125         rmapp = memslot->arch.rmap;
1126         for (i = 0; i < memslot->npages; ++i) {
1127                 int npages = kvm_test_clear_dirty_npages(kvm, rmapp);
1128                 /*
1129                  * Note that if npages > 0 then i must be a multiple of npages,
1130                  * since we always put huge-page HPTEs in the rmap chain
1131                  * corresponding to their page base address.
1132                  */
1133                 if (npages)
1134                         set_dirty_bits(map, i, npages);
1135                 ++rmapp;
1136         }
1137         preempt_enable();
1138         return 0;
1139 }
1140
1141 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
1142                             unsigned long *nb_ret)
1143 {
1144         struct kvm_memory_slot *memslot;
1145         unsigned long gfn = gpa >> PAGE_SHIFT;
1146         struct page *page, *pages[1];
1147         int npages;
1148         unsigned long hva, offset;
1149         int srcu_idx;
1150
1151         srcu_idx = srcu_read_lock(&kvm->srcu);
1152         memslot = gfn_to_memslot(kvm, gfn);
1153         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
1154                 goto err;
1155         hva = gfn_to_hva_memslot(memslot, gfn);
1156         npages = get_user_pages_fast(hva, 1, FOLL_WRITE, pages);
1157         if (npages < 1)
1158                 goto err;
1159         page = pages[0];
1160         srcu_read_unlock(&kvm->srcu, srcu_idx);
1161
1162         offset = gpa & (PAGE_SIZE - 1);
1163         if (nb_ret)
1164                 *nb_ret = PAGE_SIZE - offset;
1165         return page_address(page) + offset;
1166
1167  err:
1168         srcu_read_unlock(&kvm->srcu, srcu_idx);
1169         return NULL;
1170 }
1171
1172 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
1173                              bool dirty)
1174 {
1175         struct page *page = virt_to_page(va);
1176         struct kvm_memory_slot *memslot;
1177         unsigned long gfn;
1178         int srcu_idx;
1179
1180         put_page(page);
1181
1182         if (!dirty)
1183                 return;
1184
1185         /* We need to mark this page dirty in the memslot dirty_bitmap, if any */
1186         gfn = gpa >> PAGE_SHIFT;
1187         srcu_idx = srcu_read_lock(&kvm->srcu);
1188         memslot = gfn_to_memslot(kvm, gfn);
1189         if (memslot && memslot->dirty_bitmap)
1190                 set_bit_le(gfn - memslot->base_gfn, memslot->dirty_bitmap);
1191         srcu_read_unlock(&kvm->srcu, srcu_idx);
1192 }
1193
1194 /*
1195  * HPT resizing
1196  */
1197 static int resize_hpt_allocate(struct kvm_resize_hpt *resize)
1198 {
1199         int rc;
1200
1201         rc = kvmppc_allocate_hpt(&resize->hpt, resize->order);
1202         if (rc < 0)
1203                 return rc;
1204
1205         resize_hpt_debug(resize, "%s(): HPT @ 0x%lx\n", __func__,
1206                          resize->hpt.virt);
1207
1208         return 0;
1209 }
1210
1211 static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize,
1212                                             unsigned long idx)
1213 {
1214         struct kvm *kvm = resize->kvm;
1215         struct kvm_hpt_info *old = &kvm->arch.hpt;
1216         struct kvm_hpt_info *new = &resize->hpt;
1217         unsigned long old_hash_mask = (1ULL << (old->order - 7)) - 1;
1218         unsigned long new_hash_mask = (1ULL << (new->order - 7)) - 1;
1219         __be64 *hptep, *new_hptep;
1220         unsigned long vpte, rpte, guest_rpte;
1221         int ret;
1222         struct revmap_entry *rev;
1223         unsigned long apsize, avpn, pteg, hash;
1224         unsigned long new_idx, new_pteg, replace_vpte;
1225         int pshift;
1226
1227         hptep = (__be64 *)(old->virt + (idx << 4));
1228
1229         /* Guest is stopped, so new HPTEs can't be added or faulted
1230          * in, only unmapped or altered by host actions.  So, it's
1231          * safe to check this before we take the HPTE lock */
1232         vpte = be64_to_cpu(hptep[0]);
1233         if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
1234                 return 0; /* nothing to do */
1235
1236         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
1237                 cpu_relax();
1238
1239         vpte = be64_to_cpu(hptep[0]);
1240
1241         ret = 0;
1242         if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
1243                 /* Nothing to do */
1244                 goto out;
1245
1246         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1247                 rpte = be64_to_cpu(hptep[1]);
1248                 vpte = hpte_new_to_old_v(vpte, rpte);
1249         }
1250
1251         /* Unmap */
1252         rev = &old->rev[idx];
1253         guest_rpte = rev->guest_rpte;
1254
1255         ret = -EIO;
1256         apsize = kvmppc_actual_pgsz(vpte, guest_rpte);
1257         if (!apsize)
1258                 goto out;
1259
1260         if (vpte & HPTE_V_VALID) {
1261                 unsigned long gfn = hpte_rpn(guest_rpte, apsize);
1262                 int srcu_idx = srcu_read_lock(&kvm->srcu);
1263                 struct kvm_memory_slot *memslot =
1264                         __gfn_to_memslot(kvm_memslots(kvm), gfn);
1265
1266                 if (memslot) {
1267                         unsigned long *rmapp;
1268                         rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1269
1270                         lock_rmap(rmapp);
1271                         kvmppc_unmap_hpte(kvm, idx, memslot, rmapp, gfn);
1272                         unlock_rmap(rmapp);
1273                 }
1274
1275                 srcu_read_unlock(&kvm->srcu, srcu_idx);
1276         }
1277
1278         /* Reload PTE after unmap */
1279         vpte = be64_to_cpu(hptep[0]);
1280         BUG_ON(vpte & HPTE_V_VALID);
1281         BUG_ON(!(vpte & HPTE_V_ABSENT));
1282
1283         ret = 0;
1284         if (!(vpte & HPTE_V_BOLTED))
1285                 goto out;
1286
1287         rpte = be64_to_cpu(hptep[1]);
1288
1289         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1290                 vpte = hpte_new_to_old_v(vpte, rpte);
1291                 rpte = hpte_new_to_old_r(rpte);
1292         }
1293
1294         pshift = kvmppc_hpte_base_page_shift(vpte, rpte);
1295         avpn = HPTE_V_AVPN_VAL(vpte) & ~(((1ul << pshift) - 1) >> 23);
1296         pteg = idx / HPTES_PER_GROUP;
1297         if (vpte & HPTE_V_SECONDARY)
1298                 pteg = ~pteg;
1299
1300         if (!(vpte & HPTE_V_1TB_SEG)) {
1301                 unsigned long offset, vsid;
1302
1303                 /* We only have 28 - 23 bits of offset in avpn */
1304                 offset = (avpn & 0x1f) << 23;
1305                 vsid = avpn >> 5;
1306                 /* We can find more bits from the pteg value */
1307                 if (pshift < 23)
1308                         offset |= ((vsid ^ pteg) & old_hash_mask) << pshift;
1309
1310                 hash = vsid ^ (offset >> pshift);
1311         } else {
1312                 unsigned long offset, vsid;
1313
1314                 /* We only have 40 - 23 bits of seg_off in avpn */
1315                 offset = (avpn & 0x1ffff) << 23;
1316                 vsid = avpn >> 17;
1317                 if (pshift < 23)
1318                         offset |= ((vsid ^ (vsid << 25) ^ pteg) & old_hash_mask) << pshift;
1319
1320                 hash = vsid ^ (vsid << 25) ^ (offset >> pshift);
1321         }
1322
1323         new_pteg = hash & new_hash_mask;
1324         if (vpte & HPTE_V_SECONDARY)
1325                 new_pteg = ~hash & new_hash_mask;
1326
1327         new_idx = new_pteg * HPTES_PER_GROUP + (idx % HPTES_PER_GROUP);
1328         new_hptep = (__be64 *)(new->virt + (new_idx << 4));
1329
1330         replace_vpte = be64_to_cpu(new_hptep[0]);
1331         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1332                 unsigned long replace_rpte = be64_to_cpu(new_hptep[1]);
1333                 replace_vpte = hpte_new_to_old_v(replace_vpte, replace_rpte);
1334         }
1335
1336         if (replace_vpte & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1337                 BUG_ON(new->order >= old->order);
1338
1339                 if (replace_vpte & HPTE_V_BOLTED) {
1340                         if (vpte & HPTE_V_BOLTED)
1341                                 /* Bolted collision, nothing we can do */
1342                                 ret = -ENOSPC;
1343                         /* Discard the new HPTE */
1344                         goto out;
1345                 }
1346
1347                 /* Discard the previous HPTE */
1348         }
1349
1350         if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1351                 rpte = hpte_old_to_new_r(vpte, rpte);
1352                 vpte = hpte_old_to_new_v(vpte);
1353         }
1354
1355         new_hptep[1] = cpu_to_be64(rpte);
1356         new->rev[new_idx].guest_rpte = guest_rpte;
1357         /* No need for a barrier, since new HPT isn't active */
1358         new_hptep[0] = cpu_to_be64(vpte);
1359         unlock_hpte(new_hptep, vpte);
1360
1361 out:
1362         unlock_hpte(hptep, vpte);
1363         return ret;
1364 }
1365
1366 static int resize_hpt_rehash(struct kvm_resize_hpt *resize)
1367 {
1368         struct kvm *kvm = resize->kvm;
1369         unsigned  long i;
1370         int rc;
1371
1372         for (i = 0; i < kvmppc_hpt_npte(&kvm->arch.hpt); i++) {
1373                 rc = resize_hpt_rehash_hpte(resize, i);
1374                 if (rc != 0)
1375                         return rc;
1376         }
1377
1378         return 0;
1379 }
1380
1381 static void resize_hpt_pivot(struct kvm_resize_hpt *resize)
1382 {
1383         struct kvm *kvm = resize->kvm;
1384         struct kvm_hpt_info hpt_tmp;
1385
1386         /* Exchange the pending tables in the resize structure with
1387          * the active tables */
1388
1389         resize_hpt_debug(resize, "resize_hpt_pivot()\n");
1390
1391         spin_lock(&kvm->mmu_lock);
1392         asm volatile("ptesync" : : : "memory");
1393
1394         hpt_tmp = kvm->arch.hpt;
1395         kvmppc_set_hpt(kvm, &resize->hpt);
1396         resize->hpt = hpt_tmp;
1397
1398         spin_unlock(&kvm->mmu_lock);
1399
1400         synchronize_srcu_expedited(&kvm->srcu);
1401
1402         if (cpu_has_feature(CPU_FTR_ARCH_300))
1403                 kvmppc_setup_partition_table(kvm);
1404
1405         resize_hpt_debug(resize, "resize_hpt_pivot() done\n");
1406 }
1407
1408 static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize)
1409 {
1410         if (WARN_ON(!mutex_is_locked(&kvm->arch.mmu_setup_lock)))
1411                 return;
1412
1413         if (!resize)
1414                 return;
1415
1416         if (resize->error != -EBUSY) {
1417                 if (resize->hpt.virt)
1418                         kvmppc_free_hpt(&resize->hpt);
1419                 kfree(resize);
1420         }
1421
1422         if (kvm->arch.resize_hpt == resize)
1423                 kvm->arch.resize_hpt = NULL;
1424 }
1425
1426 static void resize_hpt_prepare_work(struct work_struct *work)
1427 {
1428         struct kvm_resize_hpt *resize = container_of(work,
1429                                                      struct kvm_resize_hpt,
1430                                                      work);
1431         struct kvm *kvm = resize->kvm;
1432         int err = 0;
1433
1434         if (WARN_ON(resize->error != -EBUSY))
1435                 return;
1436
1437         mutex_lock(&kvm->arch.mmu_setup_lock);
1438
1439         /* Request is still current? */
1440         if (kvm->arch.resize_hpt == resize) {
1441                 /* We may request large allocations here:
1442                  * do not sleep with kvm->arch.mmu_setup_lock held for a while.
1443                  */
1444                 mutex_unlock(&kvm->arch.mmu_setup_lock);
1445
1446                 resize_hpt_debug(resize, "%s(): order = %d\n", __func__,
1447                                  resize->order);
1448
1449                 err = resize_hpt_allocate(resize);
1450
1451                 /* We have strict assumption about -EBUSY
1452                  * when preparing for HPT resize.
1453                  */
1454                 if (WARN_ON(err == -EBUSY))
1455                         err = -EINPROGRESS;
1456
1457                 mutex_lock(&kvm->arch.mmu_setup_lock);
1458                 /* It is possible that kvm->arch.resize_hpt != resize
1459                  * after we grab kvm->arch.mmu_setup_lock again.
1460                  */
1461         }
1462
1463         resize->error = err;
1464
1465         if (kvm->arch.resize_hpt != resize)
1466                 resize_hpt_release(kvm, resize);
1467
1468         mutex_unlock(&kvm->arch.mmu_setup_lock);
1469 }
1470
1471 long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
1472                                      struct kvm_ppc_resize_hpt *rhpt)
1473 {
1474         unsigned long flags = rhpt->flags;
1475         unsigned long shift = rhpt->shift;
1476         struct kvm_resize_hpt *resize;
1477         int ret;
1478
1479         if (flags != 0 || kvm_is_radix(kvm))
1480                 return -EINVAL;
1481
1482         if (shift && ((shift < 18) || (shift > 46)))
1483                 return -EINVAL;
1484
1485         mutex_lock(&kvm->arch.mmu_setup_lock);
1486
1487         resize = kvm->arch.resize_hpt;
1488
1489         if (resize) {
1490                 if (resize->order == shift) {
1491                         /* Suitable resize in progress? */
1492                         ret = resize->error;
1493                         if (ret == -EBUSY)
1494                                 ret = 100; /* estimated time in ms */
1495                         else if (ret)
1496                                 resize_hpt_release(kvm, resize);
1497
1498                         goto out;
1499                 }
1500
1501                 /* not suitable, cancel it */
1502                 resize_hpt_release(kvm, resize);
1503         }
1504
1505         ret = 0;
1506         if (!shift)
1507                 goto out; /* nothing to do */
1508
1509         /* start new resize */
1510
1511         resize = kzalloc(sizeof(*resize), GFP_KERNEL);
1512         if (!resize) {
1513                 ret = -ENOMEM;
1514                 goto out;
1515         }
1516
1517         resize->error = -EBUSY;
1518         resize->order = shift;
1519         resize->kvm = kvm;
1520         INIT_WORK(&resize->work, resize_hpt_prepare_work);
1521         kvm->arch.resize_hpt = resize;
1522
1523         schedule_work(&resize->work);
1524
1525         ret = 100; /* estimated time in ms */
1526
1527 out:
1528         mutex_unlock(&kvm->arch.mmu_setup_lock);
1529         return ret;
1530 }
1531
1532 static void resize_hpt_boot_vcpu(void *opaque)
1533 {
1534         /* Nothing to do, just force a KVM exit */
1535 }
1536
1537 long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
1538                                     struct kvm_ppc_resize_hpt *rhpt)
1539 {
1540         unsigned long flags = rhpt->flags;
1541         unsigned long shift = rhpt->shift;
1542         struct kvm_resize_hpt *resize;
1543         long ret;
1544
1545         if (flags != 0 || kvm_is_radix(kvm))
1546                 return -EINVAL;
1547
1548         if (shift && ((shift < 18) || (shift > 46)))
1549                 return -EINVAL;
1550
1551         mutex_lock(&kvm->arch.mmu_setup_lock);
1552
1553         resize = kvm->arch.resize_hpt;
1554
1555         /* This shouldn't be possible */
1556         ret = -EIO;
1557         if (WARN_ON(!kvm->arch.mmu_ready))
1558                 goto out_no_hpt;
1559
1560         /* Stop VCPUs from running while we mess with the HPT */
1561         kvm->arch.mmu_ready = 0;
1562         smp_mb();
1563
1564         /* Boot all CPUs out of the guest so they re-read
1565          * mmu_ready */
1566         on_each_cpu(resize_hpt_boot_vcpu, NULL, 1);
1567
1568         ret = -ENXIO;
1569         if (!resize || (resize->order != shift))
1570                 goto out;
1571
1572         ret = resize->error;
1573         if (ret)
1574                 goto out;
1575
1576         ret = resize_hpt_rehash(resize);
1577         if (ret)
1578                 goto out;
1579
1580         resize_hpt_pivot(resize);
1581
1582 out:
1583         /* Let VCPUs run again */
1584         kvm->arch.mmu_ready = 1;
1585         smp_mb();
1586 out_no_hpt:
1587         resize_hpt_release(kvm, resize);
1588         mutex_unlock(&kvm->arch.mmu_setup_lock);
1589         return ret;
1590 }
1591
1592 /*
1593  * Functions for reading and writing the hash table via reads and
1594  * writes on a file descriptor.
1595  *
1596  * Reads return the guest view of the hash table, which has to be
1597  * pieced together from the real hash table and the guest_rpte
1598  * values in the revmap array.
1599  *
1600  * On writes, each HPTE written is considered in turn, and if it
1601  * is valid, it is written to the HPT as if an H_ENTER with the
1602  * exact flag set was done.  When the invalid count is non-zero
1603  * in the header written to the stream, the kernel will make
1604  * sure that that many HPTEs are invalid, and invalidate them
1605  * if not.
1606  */
1607
1608 struct kvm_htab_ctx {
1609         unsigned long   index;
1610         unsigned long   flags;
1611         struct kvm      *kvm;
1612         int             first_pass;
1613 };
1614
1615 #define HPTE_SIZE       (2 * sizeof(unsigned long))
1616
1617 /*
1618  * Returns 1 if this HPT entry has been modified or has pending
1619  * R/C bit changes.
1620  */
1621 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp)
1622 {
1623         unsigned long rcbits_unset;
1624
1625         if (revp->guest_rpte & HPTE_GR_MODIFIED)
1626                 return 1;
1627
1628         /* Also need to consider changes in reference and changed bits */
1629         rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1630         if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) &&
1631             (be64_to_cpu(hptp[1]) & rcbits_unset))
1632                 return 1;
1633
1634         return 0;
1635 }
1636
1637 static long record_hpte(unsigned long flags, __be64 *hptp,
1638                         unsigned long *hpte, struct revmap_entry *revp,
1639                         int want_valid, int first_pass)
1640 {
1641         unsigned long v, r, hr;
1642         unsigned long rcbits_unset;
1643         int ok = 1;
1644         int valid, dirty;
1645
1646         /* Unmodified entries are uninteresting except on the first pass */
1647         dirty = hpte_dirty(revp, hptp);
1648         if (!first_pass && !dirty)
1649                 return 0;
1650
1651         valid = 0;
1652         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1653                 valid = 1;
1654                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1655                     !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED))
1656                         valid = 0;
1657         }
1658         if (valid != want_valid)
1659                 return 0;
1660
1661         v = r = 0;
1662         if (valid || dirty) {
1663                 /* lock the HPTE so it's stable and read it */
1664                 preempt_disable();
1665                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1666                         cpu_relax();
1667                 v = be64_to_cpu(hptp[0]);
1668                 hr = be64_to_cpu(hptp[1]);
1669                 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1670                         v = hpte_new_to_old_v(v, hr);
1671                         hr = hpte_new_to_old_r(hr);
1672                 }
1673
1674                 /* re-evaluate valid and dirty from synchronized HPTE value */
1675                 valid = !!(v & HPTE_V_VALID);
1676                 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1677
1678                 /* Harvest R and C into guest view if necessary */
1679                 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1680                 if (valid && (rcbits_unset & hr)) {
1681                         revp->guest_rpte |= (hr &
1682                                 (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED;
1683                         dirty = 1;
1684                 }
1685
1686                 if (v & HPTE_V_ABSENT) {
1687                         v &= ~HPTE_V_ABSENT;
1688                         v |= HPTE_V_VALID;
1689                         valid = 1;
1690                 }
1691                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1692                         valid = 0;
1693
1694                 r = revp->guest_rpte;
1695                 /* only clear modified if this is the right sort of entry */
1696                 if (valid == want_valid && dirty) {
1697                         r &= ~HPTE_GR_MODIFIED;
1698                         revp->guest_rpte = r;
1699                 }
1700                 unlock_hpte(hptp, be64_to_cpu(hptp[0]));
1701                 preempt_enable();
1702                 if (!(valid == want_valid && (first_pass || dirty)))
1703                         ok = 0;
1704         }
1705         hpte[0] = cpu_to_be64(v);
1706         hpte[1] = cpu_to_be64(r);
1707         return ok;
1708 }
1709
1710 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1711                              size_t count, loff_t *ppos)
1712 {
1713         struct kvm_htab_ctx *ctx = file->private_data;
1714         struct kvm *kvm = ctx->kvm;
1715         struct kvm_get_htab_header hdr;
1716         __be64 *hptp;
1717         struct revmap_entry *revp;
1718         unsigned long i, nb, nw;
1719         unsigned long __user *lbuf;
1720         struct kvm_get_htab_header __user *hptr;
1721         unsigned long flags;
1722         int first_pass;
1723         unsigned long hpte[2];
1724
1725         if (!access_ok(buf, count))
1726                 return -EFAULT;
1727         if (kvm_is_radix(kvm))
1728                 return 0;
1729
1730         first_pass = ctx->first_pass;
1731         flags = ctx->flags;
1732
1733         i = ctx->index;
1734         hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1735         revp = kvm->arch.hpt.rev + i;
1736         lbuf = (unsigned long __user *)buf;
1737
1738         nb = 0;
1739         while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1740                 /* Initialize header */
1741                 hptr = (struct kvm_get_htab_header __user *)buf;
1742                 hdr.n_valid = 0;
1743                 hdr.n_invalid = 0;
1744                 nw = nb;
1745                 nb += sizeof(hdr);
1746                 lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1747
1748                 /* Skip uninteresting entries, i.e. clean on not-first pass */
1749                 if (!first_pass) {
1750                         while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1751                                !hpte_dirty(revp, hptp)) {
1752                                 ++i;
1753                                 hptp += 2;
1754                                 ++revp;
1755                         }
1756                 }
1757                 hdr.index = i;
1758
1759                 /* Grab a series of valid entries */
1760                 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1761                        hdr.n_valid < 0xffff &&
1762                        nb + HPTE_SIZE < count &&
1763                        record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1764                         /* valid entry, write it out */
1765                         ++hdr.n_valid;
1766                         if (__put_user(hpte[0], lbuf) ||
1767                             __put_user(hpte[1], lbuf + 1))
1768                                 return -EFAULT;
1769                         nb += HPTE_SIZE;
1770                         lbuf += 2;
1771                         ++i;
1772                         hptp += 2;
1773                         ++revp;
1774                 }
1775                 /* Now skip invalid entries while we can */
1776                 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1777                        hdr.n_invalid < 0xffff &&
1778                        record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1779                         /* found an invalid entry */
1780                         ++hdr.n_invalid;
1781                         ++i;
1782                         hptp += 2;
1783                         ++revp;
1784                 }
1785
1786                 if (hdr.n_valid || hdr.n_invalid) {
1787                         /* write back the header */
1788                         if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1789                                 return -EFAULT;
1790                         nw = nb;
1791                         buf = (char __user *)lbuf;
1792                 } else {
1793                         nb = nw;
1794                 }
1795
1796                 /* Check if we've wrapped around the hash table */
1797                 if (i >= kvmppc_hpt_npte(&kvm->arch.hpt)) {
1798                         i = 0;
1799                         ctx->first_pass = 0;
1800                         break;
1801                 }
1802         }
1803
1804         ctx->index = i;
1805
1806         return nb;
1807 }
1808
1809 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1810                               size_t count, loff_t *ppos)
1811 {
1812         struct kvm_htab_ctx *ctx = file->private_data;
1813         struct kvm *kvm = ctx->kvm;
1814         struct kvm_get_htab_header hdr;
1815         unsigned long i, j;
1816         unsigned long v, r;
1817         unsigned long __user *lbuf;
1818         __be64 *hptp;
1819         unsigned long tmp[2];
1820         ssize_t nb;
1821         long int err, ret;
1822         int mmu_ready;
1823         int pshift;
1824
1825         if (!access_ok(buf, count))
1826                 return -EFAULT;
1827         if (kvm_is_radix(kvm))
1828                 return -EINVAL;
1829
1830         /* lock out vcpus from running while we're doing this */
1831         mutex_lock(&kvm->arch.mmu_setup_lock);
1832         mmu_ready = kvm->arch.mmu_ready;
1833         if (mmu_ready) {
1834                 kvm->arch.mmu_ready = 0;        /* temporarily */
1835                 /* order mmu_ready vs. vcpus_running */
1836                 smp_mb();
1837                 if (atomic_read(&kvm->arch.vcpus_running)) {
1838                         kvm->arch.mmu_ready = 1;
1839                         mutex_unlock(&kvm->arch.mmu_setup_lock);
1840                         return -EBUSY;
1841                 }
1842         }
1843
1844         err = 0;
1845         for (nb = 0; nb + sizeof(hdr) <= count; ) {
1846                 err = -EFAULT;
1847                 if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1848                         break;
1849
1850                 err = 0;
1851                 if (nb + hdr.n_valid * HPTE_SIZE > count)
1852                         break;
1853
1854                 nb += sizeof(hdr);
1855                 buf += sizeof(hdr);
1856
1857                 err = -EINVAL;
1858                 i = hdr.index;
1859                 if (i >= kvmppc_hpt_npte(&kvm->arch.hpt) ||
1860                     i + hdr.n_valid + hdr.n_invalid > kvmppc_hpt_npte(&kvm->arch.hpt))
1861                         break;
1862
1863                 hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1864                 lbuf = (unsigned long __user *)buf;
1865                 for (j = 0; j < hdr.n_valid; ++j) {
1866                         __be64 hpte_v;
1867                         __be64 hpte_r;
1868
1869                         err = -EFAULT;
1870                         if (__get_user(hpte_v, lbuf) ||
1871                             __get_user(hpte_r, lbuf + 1))
1872                                 goto out;
1873                         v = be64_to_cpu(hpte_v);
1874                         r = be64_to_cpu(hpte_r);
1875                         err = -EINVAL;
1876                         if (!(v & HPTE_V_VALID))
1877                                 goto out;
1878                         pshift = kvmppc_hpte_base_page_shift(v, r);
1879                         if (pshift <= 0)
1880                                 goto out;
1881                         lbuf += 2;
1882                         nb += HPTE_SIZE;
1883
1884                         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1885                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1886                         err = -EIO;
1887                         ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1888                                                          tmp);
1889                         if (ret != H_SUCCESS) {
1890                                 pr_err("%s ret %ld i=%ld v=%lx r=%lx\n", __func__, ret, i, v, r);
1891                                 goto out;
1892                         }
1893                         if (!mmu_ready && is_vrma_hpte(v)) {
1894                                 unsigned long senc, lpcr;
1895
1896                                 senc = slb_pgsize_encoding(1ul << pshift);
1897                                 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1898                                         (VRMA_VSID << SLB_VSID_SHIFT_1T);
1899                                 if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
1900                                         lpcr = senc << (LPCR_VRMASD_SH - 4);
1901                                         kvmppc_update_lpcr(kvm, lpcr,
1902                                                            LPCR_VRMASD);
1903                                 } else {
1904                                         kvmppc_setup_partition_table(kvm);
1905                                 }
1906                                 mmu_ready = 1;
1907                         }
1908                         ++i;
1909                         hptp += 2;
1910                 }
1911
1912                 for (j = 0; j < hdr.n_invalid; ++j) {
1913                         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1914                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1915                         ++i;
1916                         hptp += 2;
1917                 }
1918                 err = 0;
1919         }
1920
1921  out:
1922         /* Order HPTE updates vs. mmu_ready */
1923         smp_wmb();
1924         kvm->arch.mmu_ready = mmu_ready;
1925         mutex_unlock(&kvm->arch.mmu_setup_lock);
1926
1927         if (err)
1928                 return err;
1929         return nb;
1930 }
1931
1932 static int kvm_htab_release(struct inode *inode, struct file *filp)
1933 {
1934         struct kvm_htab_ctx *ctx = filp->private_data;
1935
1936         filp->private_data = NULL;
1937         if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1938                 atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1939         kvm_put_kvm(ctx->kvm);
1940         kfree(ctx);
1941         return 0;
1942 }
1943
1944 static const struct file_operations kvm_htab_fops = {
1945         .read           = kvm_htab_read,
1946         .write          = kvm_htab_write,
1947         .llseek         = default_llseek,
1948         .release        = kvm_htab_release,
1949 };
1950
1951 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1952 {
1953         int ret;
1954         struct kvm_htab_ctx *ctx;
1955         int rwflag;
1956
1957         /* reject flags we don't recognize */
1958         if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1959                 return -EINVAL;
1960         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1961         if (!ctx)
1962                 return -ENOMEM;
1963         kvm_get_kvm(kvm);
1964         ctx->kvm = kvm;
1965         ctx->index = ghf->start_index;
1966         ctx->flags = ghf->flags;
1967         ctx->first_pass = 1;
1968
1969         rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1970         ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
1971         if (ret < 0) {
1972                 kfree(ctx);
1973                 kvm_put_kvm_no_destroy(kvm);
1974                 return ret;
1975         }
1976
1977         if (rwflag == O_RDONLY) {
1978                 mutex_lock(&kvm->slots_lock);
1979                 atomic_inc(&kvm->arch.hpte_mod_interest);
1980                 /* make sure kvmppc_do_h_enter etc. see the increment */
1981                 synchronize_srcu_expedited(&kvm->srcu);
1982                 mutex_unlock(&kvm->slots_lock);
1983         }
1984
1985         return ret;
1986 }
1987
1988 struct debugfs_htab_state {
1989         struct kvm      *kvm;
1990         struct mutex    mutex;
1991         unsigned long   hpt_index;
1992         int             chars_left;
1993         int             buf_index;
1994         char            buf[64];
1995 };
1996
1997 static int debugfs_htab_open(struct inode *inode, struct file *file)
1998 {
1999         struct kvm *kvm = inode->i_private;
2000         struct debugfs_htab_state *p;
2001
2002         p = kzalloc(sizeof(*p), GFP_KERNEL);
2003         if (!p)
2004                 return -ENOMEM;
2005
2006         kvm_get_kvm(kvm);
2007         p->kvm = kvm;
2008         mutex_init(&p->mutex);
2009         file->private_data = p;
2010
2011         return nonseekable_open(inode, file);
2012 }
2013
2014 static int debugfs_htab_release(struct inode *inode, struct file *file)
2015 {
2016         struct debugfs_htab_state *p = file->private_data;
2017
2018         kvm_put_kvm(p->kvm);
2019         kfree(p);
2020         return 0;
2021 }
2022
2023 static ssize_t debugfs_htab_read(struct file *file, char __user *buf,
2024                                  size_t len, loff_t *ppos)
2025 {
2026         struct debugfs_htab_state *p = file->private_data;
2027         ssize_t ret, r;
2028         unsigned long i, n;
2029         unsigned long v, hr, gr;
2030         struct kvm *kvm;
2031         __be64 *hptp;
2032
2033         kvm = p->kvm;
2034         if (kvm_is_radix(kvm))
2035                 return 0;
2036
2037         ret = mutex_lock_interruptible(&p->mutex);
2038         if (ret)
2039                 return ret;
2040
2041         if (p->chars_left) {
2042                 n = p->chars_left;
2043                 if (n > len)
2044                         n = len;
2045                 r = copy_to_user(buf, p->buf + p->buf_index, n);
2046                 n -= r;
2047                 p->chars_left -= n;
2048                 p->buf_index += n;
2049                 buf += n;
2050                 len -= n;
2051                 ret = n;
2052                 if (r) {
2053                         if (!n)
2054                                 ret = -EFAULT;
2055                         goto out;
2056                 }
2057         }
2058
2059         i = p->hpt_index;
2060         hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
2061         for (; len != 0 && i < kvmppc_hpt_npte(&kvm->arch.hpt);
2062              ++i, hptp += 2) {
2063                 if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)))
2064                         continue;
2065
2066                 /* lock the HPTE so it's stable and read it */
2067                 preempt_disable();
2068                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
2069                         cpu_relax();
2070                 v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK;
2071                 hr = be64_to_cpu(hptp[1]);
2072                 gr = kvm->arch.hpt.rev[i].guest_rpte;
2073                 unlock_hpte(hptp, v);
2074                 preempt_enable();
2075
2076                 if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
2077                         continue;
2078
2079                 n = scnprintf(p->buf, sizeof(p->buf),
2080                               "%6lx %.16lx %.16lx %.16lx\n",
2081                               i, v, hr, gr);
2082                 p->chars_left = n;
2083                 if (n > len)
2084                         n = len;
2085                 r = copy_to_user(buf, p->buf, n);
2086                 n -= r;
2087                 p->chars_left -= n;
2088                 p->buf_index = n;
2089                 buf += n;
2090                 len -= n;
2091                 ret += n;
2092                 if (r) {
2093                         if (!ret)
2094                                 ret = -EFAULT;
2095                         goto out;
2096                 }
2097         }
2098         p->hpt_index = i;
2099
2100  out:
2101         mutex_unlock(&p->mutex);
2102         return ret;
2103 }
2104
2105 static ssize_t debugfs_htab_write(struct file *file, const char __user *buf,
2106                            size_t len, loff_t *ppos)
2107 {
2108         return -EACCES;
2109 }
2110
2111 static const struct file_operations debugfs_htab_fops = {
2112         .owner   = THIS_MODULE,
2113         .open    = debugfs_htab_open,
2114         .release = debugfs_htab_release,
2115         .read    = debugfs_htab_read,
2116         .write   = debugfs_htab_write,
2117         .llseek  = generic_file_llseek,
2118 };
2119
2120 void kvmppc_mmu_debugfs_init(struct kvm *kvm)
2121 {
2122         debugfs_create_file("htab", 0400, kvm->debugfs_dentry, kvm,
2123                             &debugfs_htab_fops);
2124 }
2125
2126 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
2127 {
2128         struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
2129
2130         vcpu->arch.slb_nr = 32;         /* POWER7/POWER8 */
2131
2132         mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
2133
2134         vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
2135 }