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
  31 #include <asm/tlbflush.h>
  32 #include <asm/kvm_ppc.h>
  33 #include <asm/kvm_book3s.h>
  34 #include <asm/mmu-hash64.h>
  35 #include <asm/hvcall.h>
  36 #include <asm/synch.h>
  37 #include <asm/ppc-opcode.h>
  38 #include <asm/cputable.h>
  39
  40 /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */
  41 #define MAX_LPID_970    63
  42
  43 /* Power architecture requires HPT is at least 256kB */
  44 #define PPC_MIN_HPT_ORDER       18
  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 static void kvmppc_rmap_reset(struct kvm *kvm);
  50
  51 long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
  52 {
  53         unsigned long hpt;
  54         struct revmap_entry *rev;
  55         struct kvmppc_linear_info *li;
  56         long order = kvm_hpt_order;
  57
  58         if (htab_orderp) {
  59                 order = *htab_orderp;
  60                 if (order < PPC_MIN_HPT_ORDER)
  61                         order = PPC_MIN_HPT_ORDER;
  62         }
  63
  64         /*
  65          * If the user wants a different size from default,
  66          * try first to allocate it from the kernel page allocator.
  67          */
  68         hpt = 0;
  69         if (order != kvm_hpt_order) {
  70                 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
  71                                        __GFP_NOWARN, order - PAGE_SHIFT);
  72                 if (!hpt)
  73                         --order;
  74         }
  75
  76         /* Next try to allocate from the preallocated pool */
  77         if (!hpt) {
  78                 li = kvm_alloc_hpt();
  79                 if (li) {
  80                         hpt = (ulong)li->base_virt;
  81                         kvm->arch.hpt_li = li;
  82                         order = kvm_hpt_order;
  83                 }
  84         }
  85
  86         /* Lastly try successively smaller sizes from the page allocator */
  87         while (!hpt && order > PPC_MIN_HPT_ORDER) {
  88                 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
  89                                        __GFP_NOWARN, order - PAGE_SHIFT);
  90                 if (!hpt)
  91                         --order;
  92         }
  93
  94         if (!hpt)
  95                 return -ENOMEM;
  96
  97         kvm->arch.hpt_virt = hpt;
  98         kvm->arch.hpt_order = order;
  99         /* HPTEs are 2**4 bytes long */
 100         kvm->arch.hpt_npte = 1ul << (order - 4);
 101         /* 128 (2**7) bytes in each HPTEG */
 102         kvm->arch.hpt_mask = (1ul << (order - 7)) - 1;
 103
 104         /* Allocate reverse map array */
 105         rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte);
 106         if (!rev) {
 107                 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
 108                 goto out_freehpt;
 109         }
 110         kvm->arch.revmap = rev;
 111         kvm->arch.sdr1 = __pa(hpt) | (order - 18);
 112
 113         pr_info("KVM guest htab at %lx (order %ld), LPID %x\n",
 114                 hpt, order, kvm->arch.lpid);
 115
 116         if (htab_orderp)
 117                 *htab_orderp = order;
 118         return 0;
 119
 120  out_freehpt:
 121         if (kvm->arch.hpt_li)
 122                 kvm_release_hpt(kvm->arch.hpt_li);
 123         else
 124                 free_pages(hpt, order - PAGE_SHIFT);
 125         return -ENOMEM;
 126 }
 127
 128 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
 129 {
 130         long err = -EBUSY;
 131         long order;
 132
 133         mutex_lock(&kvm->lock);
 134         if (kvm->arch.rma_setup_done) {
 135                 kvm->arch.rma_setup_done = 0;
 136                 /* order rma_setup_done vs. vcpus_running */
 137                 smp_mb();
 138                 if (atomic_read(&kvm->arch.vcpus_running)) {
 139                         kvm->arch.rma_setup_done = 1;
 140                         goto out;
 141                 }
 142         }
 143         if (kvm->arch.hpt_virt) {
 144                 order = kvm->arch.hpt_order;
 145                 /* Set the entire HPT to 0, i.e. invalid HPTEs */
 146                 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order);
 147                 /*
 148                  * Reset all the reverse-mapping chains for all memslots
 149                  */
 150                 kvmppc_rmap_reset(kvm);
 151                 /* Ensure that each vcpu will flush its TLB on next entry. */
 152                 cpumask_setall(&kvm->arch.need_tlb_flush);
 153                 *htab_orderp = order;
 154                 err = 0;
 155         } else {
 156                 err = kvmppc_alloc_hpt(kvm, htab_orderp);
 157                 order = *htab_orderp;
 158         }
 159  out:
 160         mutex_unlock(&kvm->lock);
 161         return err;
 162 }
 163
 164 void kvmppc_free_hpt(struct kvm *kvm)
 165 {
 166         kvmppc_free_lpid(kvm->arch.lpid);
 167         vfree(kvm->arch.revmap);
 168         if (kvm->arch.hpt_li)
 169                 kvm_release_hpt(kvm->arch.hpt_li);
 170         else
 171                 free_pages(kvm->arch.hpt_virt,
 172                            kvm->arch.hpt_order - PAGE_SHIFT);
 173 }
 174
 175 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
 176 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
 177 {
 178         return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
 179 }
 180
 181 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
 182 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
 183 {
 184         return (pgsize == 0x10000) ? 0x1000 : 0;
 185 }
 186
 187 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
 188                      unsigned long porder)
 189 {
 190         unsigned long i;
 191         unsigned long npages;
 192         unsigned long hp_v, hp_r;
 193         unsigned long addr, hash;
 194         unsigned long psize;
 195         unsigned long hp0, hp1;
 196         unsigned long idx_ret;
 197         long ret;
 198         struct kvm *kvm = vcpu->kvm;
 199
 200         psize = 1ul << porder;
 201         npages = memslot->npages >> (porder - PAGE_SHIFT);
 202
 203         /* VRMA can't be > 1TB */
 204         if (npages > 1ul << (40 - porder))
 205                 npages = 1ul << (40 - porder);
 206         /* Can't use more than 1 HPTE per HPTEG */
 207         if (npages > kvm->arch.hpt_mask + 1)
 208                 npages = kvm->arch.hpt_mask + 1;
 209
 210         hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
 211                 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
 212         hp1 = hpte1_pgsize_encoding(psize) |
 213                 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
 214
 215         for (i = 0; i < npages; ++i) {
 216                 addr = i << porder;
 217                 /* can't use hpt_hash since va > 64 bits */
 218                 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask;
 219                 /*
 220                  * We assume that the hash table is empty and no
 221                  * vcpus are using it at this stage.  Since we create
 222                  * at most one HPTE per HPTEG, we just assume entry 7
 223                  * is available and use it.
 224                  */
 225                 hash = (hash << 3) + 7;
 226                 hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
 227                 hp_r = hp1 | addr;
 228                 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
 229                                                  &idx_ret);
 230                 if (ret != H_SUCCESS) {
 231                         pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
 232                                addr, ret);
 233                         break;
 234                 }
 235         }
 236 }
 237
 238 int kvmppc_mmu_hv_init(void)
 239 {
 240         unsigned long host_lpid, rsvd_lpid;
 241
 242         if (!cpu_has_feature(CPU_FTR_HVMODE))
 243                 return -EINVAL;
 244
 245         /* POWER7 has 10-bit LPIDs, PPC970 and e500mc have 6-bit LPIDs */
 246         if (cpu_has_feature(CPU_FTR_ARCH_206)) {
 247                 host_lpid = mfspr(SPRN_LPID);   /* POWER7 */
 248                 rsvd_lpid = LPID_RSVD;
 249         } else {
 250                 host_lpid = 0;                  /* PPC970 */
 251                 rsvd_lpid = MAX_LPID_970;
 252         }
 253
 254         kvmppc_init_lpid(rsvd_lpid + 1);
 255
 256         kvmppc_claim_lpid(host_lpid);
 257         /* rsvd_lpid is reserved for use in partition switching */
 258         kvmppc_claim_lpid(rsvd_lpid);
 259
 260         return 0;
 261 }
 262
 263 void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
 264 {
 265 }
 266
 267 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
 268 {
 269         kvmppc_set_msr(vcpu, MSR_SF | MSR_ME);
 270 }
 271
 272 /*
 273  * This is called to get a reference to a guest page if there isn't
 274  * one already in the memslot->arch.slot_phys[] array.
 275  */
 276 static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn,
 277                                   struct kvm_memory_slot *memslot,
 278                                   unsigned long psize)
 279 {
 280         unsigned long start;
 281         long np, err;
 282         struct page *page, *hpage, *pages[1];
 283         unsigned long s, pgsize;
 284         unsigned long *physp;
 285         unsigned int is_io, got, pgorder;
 286         struct vm_area_struct *vma;
 287         unsigned long pfn, i, npages;
 288
 289         physp = memslot->arch.slot_phys;
 290         if (!physp)
 291                 return -EINVAL;
 292         if (physp[gfn - memslot->base_gfn])
 293                 return 0;
 294
 295         is_io = 0;
 296         got = 0;
 297         page = NULL;
 298         pgsize = psize;
 299         err = -EINVAL;
 300         start = gfn_to_hva_memslot(memslot, gfn);
 301
 302         /* Instantiate and get the page we want access to */
 303         np = get_user_pages_fast(start, 1, 1, pages);
 304         if (np != 1) {
 305                 /* Look up the vma for the page */
 306                 down_read(&current->mm->mmap_sem);
 307                 vma = find_vma(current->mm, start);
 308                 if (!vma || vma->vm_start > start ||
 309                     start + psize > vma->vm_end ||
 310                     !(vma->vm_flags & VM_PFNMAP))
 311                         goto up_err;
 312                 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
 313                 pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
 314                 /* check alignment of pfn vs. requested page size */
 315                 if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1)))
 316                         goto up_err;
 317                 up_read(&current->mm->mmap_sem);
 318
 319         } else {
 320                 page = pages[0];
 321                 got = KVMPPC_GOT_PAGE;
 322
 323                 /* See if this is a large page */
 324                 s = PAGE_SIZE;
 325                 if (PageHuge(page)) {
 326                         hpage = compound_head(page);
 327                         s <<= compound_order(hpage);
 328                         /* Get the whole large page if slot alignment is ok */
 329                         if (s > psize && slot_is_aligned(memslot, s) &&
 330                             !(memslot->userspace_addr & (s - 1))) {
 331                                 start &= ~(s - 1);
 332                                 pgsize = s;
 333                                 get_page(hpage);
 334                                 put_page(page);
 335                                 page = hpage;
 336                         }
 337                 }
 338                 if (s < psize)
 339                         goto out;
 340                 pfn = page_to_pfn(page);
 341         }
 342
 343         npages = pgsize >> PAGE_SHIFT;
 344         pgorder = __ilog2(npages);
 345         physp += (gfn - memslot->base_gfn) & ~(npages - 1);
 346         spin_lock(&kvm->arch.slot_phys_lock);
 347         for (i = 0; i < npages; ++i) {
 348                 if (!physp[i]) {
 349                         physp[i] = ((pfn + i) << PAGE_SHIFT) +
 350                                 got + is_io + pgorder;
 351                         got = 0;
 352                 }
 353         }
 354         spin_unlock(&kvm->arch.slot_phys_lock);
 355         err = 0;
 356
 357  out:
 358         if (got)
 359                 put_page(page);
 360         return err;
 361
 362  up_err:
 363         up_read(&current->mm->mmap_sem);
 364         return err;
 365 }
 366
 367 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
 368                                 long pte_index, unsigned long pteh,
 369                                 unsigned long ptel, unsigned long *pte_idx_ret)
 370 {
 371         unsigned long psize, gpa, gfn;
 372         struct kvm_memory_slot *memslot;
 373         long ret;
 374
 375         if (kvm->arch.using_mmu_notifiers)
 376                 goto do_insert;
 377
 378         psize = hpte_page_size(pteh, ptel);
 379         if (!psize)
 380                 return H_PARAMETER;
 381
 382         pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID);
 383
 384         /* Find the memslot (if any) for this address */
 385         gpa = (ptel & HPTE_R_RPN) & ~(psize - 1);
 386         gfn = gpa >> PAGE_SHIFT;
 387         memslot = gfn_to_memslot(kvm, gfn);
 388         if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) {
 389                 if (!slot_is_aligned(memslot, psize))
 390                         return H_PARAMETER;
 391                 if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0)
 392                         return H_PARAMETER;
 393         }
 394
 395  do_insert:
 396         /* Protect linux PTE lookup from page table destruction */
 397         rcu_read_lock_sched();  /* this disables preemption too */
 398         ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
 399                                 current->mm->pgd, false, pte_idx_ret);
 400         rcu_read_unlock_sched();
 401         if (ret == H_TOO_HARD) {
 402                 /* this can't happen */
 403                 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
 404                 ret = H_RESOURCE;       /* or something */
 405         }
 406         return ret;
 407
 408 }
 409
 410 /*
 411  * We come here on a H_ENTER call from the guest when we are not
 412  * using mmu notifiers and we don't have the requested page pinned
 413  * already.
 414  */
 415 long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
 416                              long pte_index, unsigned long pteh,
 417                              unsigned long ptel)
 418 {
 419         return kvmppc_virtmode_do_h_enter(vcpu->kvm, flags, pte_index,
 420                                           pteh, ptel, &vcpu->arch.gpr[4]);
 421 }
 422
 423 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
 424                                                          gva_t eaddr)
 425 {
 426         u64 mask;
 427         int i;
 428
 429         for (i = 0; i < vcpu->arch.slb_nr; i++) {
 430                 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
 431                         continue;
 432
 433                 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
 434                         mask = ESID_MASK_1T;
 435                 else
 436                         mask = ESID_MASK;
 437
 438                 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
 439                         return &vcpu->arch.slb[i];
 440         }
 441         return NULL;
 442 }
 443
 444 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
 445                         unsigned long ea)
 446 {
 447         unsigned long ra_mask;
 448
 449         ra_mask = hpte_page_size(v, r) - 1;
 450         return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
 451 }
 452
 453 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 454                         struct kvmppc_pte *gpte, bool data)
 455 {
 456         struct kvm *kvm = vcpu->kvm;
 457         struct kvmppc_slb *slbe;
 458         unsigned long slb_v;
 459         unsigned long pp, key;
 460         unsigned long v, gr;
 461         unsigned long *hptep;
 462         int index;
 463         int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
 464
 465         /* Get SLB entry */
 466         if (virtmode) {
 467                 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
 468                 if (!slbe)
 469                         return -EINVAL;
 470                 slb_v = slbe->origv;
 471         } else {
 472                 /* real mode access */
 473                 slb_v = vcpu->kvm->arch.vrma_slb_v;
 474         }
 475
 476         preempt_disable();
 477         /* Find the HPTE in the hash table */
 478         index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
 479                                          HPTE_V_VALID | HPTE_V_ABSENT);
 480         if (index < 0) {
 481                 preempt_enable();
 482                 return -ENOENT;
 483         }
 484         hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
 485         v = hptep[0] & ~HPTE_V_HVLOCK;
 486         gr = kvm->arch.revmap[index].guest_rpte;
 487
 488         /* Unlock the HPTE */
 489         asm volatile("lwsync" : : : "memory");
 490         hptep[0] = v;
 491         preempt_enable();
 492
 493         gpte->eaddr = eaddr;
 494         gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
 495
 496         /* Get PP bits and key for permission check */
 497         pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
 498         key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
 499         key &= slb_v;
 500
 501         /* Calculate permissions */
 502         gpte->may_read = hpte_read_permission(pp, key);
 503         gpte->may_write = hpte_write_permission(pp, key);
 504         gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
 505
 506         /* Storage key permission check for POWER7 */
 507         if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) {
 508                 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
 509                 if (amrfield & 1)
 510                         gpte->may_read = 0;
 511                 if (amrfield & 2)
 512                         gpte->may_write = 0;
 513         }
 514
 515         /* Get the guest physical address */
 516         gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
 517         return 0;
 518 }
 519
 520 /*
 521  * Quick test for whether an instruction is a load or a store.
 522  * If the instruction is a load or a store, then this will indicate
 523  * which it is, at least on server processors.  (Embedded processors
 524  * have some external PID instructions that don't follow the rule
 525  * embodied here.)  If the instruction isn't a load or store, then
 526  * this doesn't return anything useful.
 527  */
 528 static int instruction_is_store(unsigned int instr)
 529 {
 530         unsigned int mask;
 531
 532         mask = 0x10000000;
 533         if ((instr & 0xfc000000) == 0x7c000000)
 534                 mask = 0x100;           /* major opcode 31 */
 535         return (instr & mask) != 0;
 536 }
 537
 538 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
 539                                   unsigned long gpa, gva_t ea, int is_store)
 540 {
 541         int ret;
 542         u32 last_inst;
 543         unsigned long srr0 = kvmppc_get_pc(vcpu);
 544
 545         /* We try to load the last instruction.  We don't let
 546          * emulate_instruction do it as it doesn't check what
 547          * kvmppc_ld returns.
 548          * If we fail, we just return to the guest and try executing it again.
 549          */
 550         if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) {
 551                 ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
 552                 if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED)
 553                         return RESUME_GUEST;
 554                 vcpu->arch.last_inst = last_inst;
 555         }
 556
 557         /*
 558          * WARNING: We do not know for sure whether the instruction we just
 559          * read from memory is the same that caused the fault in the first
 560          * place.  If the instruction we read is neither an load or a store,
 561          * then it can't access memory, so we don't need to worry about
 562          * enforcing access permissions.  So, assuming it is a load or
 563          * store, we just check that its direction (load or store) is
 564          * consistent with the original fault, since that's what we
 565          * checked the access permissions against.  If there is a mismatch
 566          * we just return and retry the instruction.
 567          */
 568
 569         if (instruction_is_store(vcpu->arch.last_inst) != !!is_store)
 570                 return RESUME_GUEST;
 571
 572         /*
 573          * Emulated accesses are emulated by looking at the hash for
 574          * translation once, then performing the access later. The
 575          * translation could be invalidated in the meantime in which
 576          * point performing the subsequent memory access on the old
 577          * physical address could possibly be a security hole for the
 578          * guest (but not the host).
 579          *
 580          * This is less of an issue for MMIO stores since they aren't
 581          * globally visible. It could be an issue for MMIO loads to
 582          * a certain extent but we'll ignore it for now.
 583          */
 584
 585         vcpu->arch.paddr_accessed = gpa;
 586         vcpu->arch.vaddr_accessed = ea;
 587         return kvmppc_emulate_mmio(run, vcpu);
 588 }
 589
 590 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 591                                 unsigned long ea, unsigned long dsisr)
 592 {
 593         struct kvm *kvm = vcpu->kvm;
 594         unsigned long *hptep, hpte[3], r;
 595         unsigned long mmu_seq, psize, pte_size;
 596         unsigned long gpa, gfn, hva, pfn;
 597         struct kvm_memory_slot *memslot;
 598         unsigned long *rmap;
 599         struct revmap_entry *rev;
 600         struct page *page, *pages[1];
 601         long index, ret, npages;
 602         unsigned long is_io;
 603         unsigned int writing, write_ok;
 604         struct vm_area_struct *vma;
 605         unsigned long rcbits;
 606
 607         /*
 608          * Real-mode code has already searched the HPT and found the
 609          * entry we're interested in.  Lock the entry and check that
 610          * it hasn't changed.  If it has, just return and re-execute the
 611          * instruction.
 612          */
 613         if (ea != vcpu->arch.pgfault_addr)
 614                 return RESUME_GUEST;
 615         index = vcpu->arch.pgfault_index;
 616         hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
 617         rev = &kvm->arch.revmap[index];
 618         preempt_disable();
 619         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
 620                 cpu_relax();
 621         hpte[0] = hptep[0] & ~HPTE_V_HVLOCK;
 622         hpte[1] = hptep[1];
 623         hpte[2] = r = rev->guest_rpte;
 624         asm volatile("lwsync" : : : "memory");
 625         hptep[0] = hpte[0];
 626         preempt_enable();
 627
 628         if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
 629             hpte[1] != vcpu->arch.pgfault_hpte[1])
 630                 return RESUME_GUEST;
 631
 632         /* Translate the logical address and get the page */
 633         psize = hpte_page_size(hpte[0], r);
 634         gpa = (r & HPTE_R_RPN & ~(psize - 1)) | (ea & (psize - 1));
 635         gfn = gpa >> PAGE_SHIFT;
 636         memslot = gfn_to_memslot(kvm, gfn);
 637
 638         /* No memslot means it's an emulated MMIO region */
 639         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
 640                 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
 641                                               dsisr & DSISR_ISSTORE);
 642
 643         if (!kvm->arch.using_mmu_notifiers)
 644                 return -EFAULT;         /* should never get here */
 645
 646         /* used to check for invalidations in progress */
 647         mmu_seq = kvm->mmu_notifier_seq;
 648         smp_rmb();
 649
 650         is_io = 0;
 651         pfn = 0;
 652         page = NULL;
 653         pte_size = PAGE_SIZE;
 654         writing = (dsisr & DSISR_ISSTORE) != 0;
 655         /* If writing != 0, then the HPTE must allow writing, if we get here */
 656         write_ok = writing;
 657         hva = gfn_to_hva_memslot(memslot, gfn);
 658         npages = get_user_pages_fast(hva, 1, writing, pages);
 659         if (npages < 1) {
 660                 /* Check if it's an I/O mapping */
 661                 down_read(&current->mm->mmap_sem);
 662                 vma = find_vma(current->mm, hva);
 663                 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
 664                     (vma->vm_flags & VM_PFNMAP)) {
 665                         pfn = vma->vm_pgoff +
 666                                 ((hva - vma->vm_start) >> PAGE_SHIFT);
 667                         pte_size = psize;
 668                         is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
 669                         write_ok = vma->vm_flags & VM_WRITE;
 670                 }
 671                 up_read(&current->mm->mmap_sem);
 672                 if (!pfn)
 673                         return -EFAULT;
 674         } else {
 675                 page = pages[0];
 676                 if (PageHuge(page)) {
 677                         page = compound_head(page);
 678                         pte_size <<= compound_order(page);
 679                 }
 680                 /* if the guest wants write access, see if that is OK */
 681                 if (!writing && hpte_is_writable(r)) {
 682                         pte_t *ptep, pte;
 683
 684                         /*
 685                          * We need to protect against page table destruction
 686                          * while looking up and updating the pte.
 687                          */
 688                         rcu_read_lock_sched();
 689                         ptep = find_linux_pte_or_hugepte(current->mm->pgd,
 690                                                          hva, NULL);
 691                         if (ptep && pte_present(*ptep)) {
 692                                 pte = kvmppc_read_update_linux_pte(ptep, 1);
 693                                 if (pte_write(pte))
 694                                         write_ok = 1;
 695                         }
 696                         rcu_read_unlock_sched();
 697                 }
 698                 pfn = page_to_pfn(page);
 699         }
 700
 701         ret = -EFAULT;
 702         if (psize > pte_size)
 703                 goto out_put;
 704
 705         /* Check WIMG vs. the actual page we're accessing */
 706         if (!hpte_cache_flags_ok(r, is_io)) {
 707                 if (is_io)
 708                         return -EFAULT;
 709                 /*
 710                  * Allow guest to map emulated device memory as
 711                  * uncacheable, but actually make it cacheable.
 712                  */
 713                 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
 714         }
 715
 716         /* Set the HPTE to point to pfn */
 717         r = (r & ~(HPTE_R_PP0 - pte_size)) | (pfn << PAGE_SHIFT);
 718         if (hpte_is_writable(r) && !write_ok)
 719                 r = hpte_make_readonly(r);
 720         ret = RESUME_GUEST;
 721         preempt_disable();
 722         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
 723                 cpu_relax();
 724         if ((hptep[0] & ~HPTE_V_HVLOCK) != hpte[0] || hptep[1] != hpte[1] ||
 725             rev->guest_rpte != hpte[2])
 726                 /* HPTE has been changed under us; let the guest retry */
 727                 goto out_unlock;
 728         hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
 729
 730         rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
 731         lock_rmap(rmap);
 732
 733         /* Check if we might have been invalidated; let the guest retry if so */
 734         ret = RESUME_GUEST;
 735         if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
 736                 unlock_rmap(rmap);
 737                 goto out_unlock;
 738         }
 739
 740         /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
 741         rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
 742         r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
 743
 744         if (hptep[0] & HPTE_V_VALID) {
 745                 /* HPTE was previously valid, so we need to invalidate it */
 746                 unlock_rmap(rmap);
 747                 hptep[0] |= HPTE_V_ABSENT;
 748                 kvmppc_invalidate_hpte(kvm, hptep, index);
 749                 /* don't lose previous R and C bits */
 750                 r |= hptep[1] & (HPTE_R_R | HPTE_R_C);
 751         } else {
 752                 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
 753         }
 754
 755         hptep[1] = r;
 756         eieio();
 757         hptep[0] = hpte[0];
 758         asm volatile("ptesync" : : : "memory");
 759         preempt_enable();
 760         if (page && hpte_is_writable(r))
 761                 SetPageDirty(page);
 762
 763  out_put:
 764         if (page) {
 765                 /*
 766                  * We drop pages[0] here, not page because page might
 767                  * have been set to the head page of a compound, but
 768                  * we have to drop the reference on the correct tail
 769                  * page to match the get inside gup()
 770                  */
 771                 put_page(pages[0]);
 772         }
 773         return ret;
 774
 775  out_unlock:
 776         hptep[0] &= ~HPTE_V_HVLOCK;
 777         preempt_enable();
 778         goto out_put;
 779 }
 780
 781 static void kvmppc_rmap_reset(struct kvm *kvm)
 782 {
 783         struct kvm_memslots *slots;
 784         struct kvm_memory_slot *memslot;
 785         int srcu_idx;
 786
 787         srcu_idx = srcu_read_lock(&kvm->srcu);
 788         slots = kvm->memslots;
 789         kvm_for_each_memslot(memslot, slots) {
 790                 /*
 791                  * This assumes it is acceptable to lose reference and
 792                  * change bits across a reset.
 793                  */
 794                 memset(memslot->arch.rmap, 0,
 795                        memslot->npages * sizeof(*memslot->arch.rmap));
 796         }
 797         srcu_read_unlock(&kvm->srcu, srcu_idx);
 798 }
 799
 800 static int kvm_handle_hva_range(struct kvm *kvm,
 801                                 unsigned long start,
 802                                 unsigned long end,
 803                                 int (*handler)(struct kvm *kvm,
 804                                                unsigned long *rmapp,
 805                                                unsigned long gfn))
 806 {
 807         int ret;
 808         int retval = 0;
 809         struct kvm_memslots *slots;
 810         struct kvm_memory_slot *memslot;
 811
 812         slots = kvm_memslots(kvm);
 813         kvm_for_each_memslot(memslot, slots) {
 814                 unsigned long hva_start, hva_end;
 815                 gfn_t gfn, gfn_end;
 816
 817                 hva_start = max(start, memslot->userspace_addr);
 818                 hva_end = min(end, memslot->userspace_addr +
 819                                         (memslot->npages << PAGE_SHIFT));
 820                 if (hva_start >= hva_end)
 821                         continue;
 822                 /*
 823                  * {gfn(page) | page intersects with [hva_start, hva_end)} =
 824                  * {gfn, gfn+1, ..., gfn_end-1}.
 825                  */
 826                 gfn = hva_to_gfn_memslot(hva_start, memslot);
 827                 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
 828
 829                 for (; gfn < gfn_end; ++gfn) {
 830                         gfn_t gfn_offset = gfn - memslot->base_gfn;
 831
 832                         ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn);
 833                         retval |= ret;
 834                 }
 835         }
 836
 837         return retval;
 838 }
 839
 840 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
 841                           int (*handler)(struct kvm *kvm, unsigned long *rmapp,
 842                                          unsigned long gfn))
 843 {
 844         return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
 845 }
 846
 847 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
 848                            unsigned long gfn)
 849 {
 850         struct revmap_entry *rev = kvm->arch.revmap;
 851         unsigned long h, i, j;
 852         unsigned long *hptep;
 853         unsigned long ptel, psize, rcbits;
 854
 855         for (;;) {
 856                 lock_rmap(rmapp);
 857                 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 858                         unlock_rmap(rmapp);
 859                         break;
 860                 }
 861
 862                 /*
 863                  * To avoid an ABBA deadlock with the HPTE lock bit,
 864                  * we can't spin on the HPTE lock while holding the
 865                  * rmap chain lock.
 866                  */
 867                 i = *rmapp & KVMPPC_RMAP_INDEX;
 868                 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
 869                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 870                         /* unlock rmap before spinning on the HPTE lock */
 871                         unlock_rmap(rmapp);
 872                         while (hptep[0] & HPTE_V_HVLOCK)
 873                                 cpu_relax();
 874                         continue;
 875                 }
 876                 j = rev[i].forw;
 877                 if (j == i) {
 878                         /* chain is now empty */
 879                         *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
 880                 } else {
 881                         /* remove i from chain */
 882                         h = rev[i].back;
 883                         rev[h].forw = j;
 884                         rev[j].back = h;
 885                         rev[i].forw = rev[i].back = i;
 886                         *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
 887                 }
 888
 889                 /* Now check and modify the HPTE */
 890                 ptel = rev[i].guest_rpte;
 891                 psize = hpte_page_size(hptep[0], ptel);
 892                 if ((hptep[0] & HPTE_V_VALID) &&
 893                     hpte_rpn(ptel, psize) == gfn) {
 894                         if (kvm->arch.using_mmu_notifiers)
 895                                 hptep[0] |= HPTE_V_ABSENT;
 896                         kvmppc_invalidate_hpte(kvm, hptep, i);
 897                         /* Harvest R and C */
 898                         rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C);
 899                         *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
 900                         if (rcbits & ~rev[i].guest_rpte) {
 901                                 rev[i].guest_rpte = ptel | rcbits;
 902                                 note_hpte_modification(kvm, &rev[i]);
 903                         }
 904                 }
 905                 unlock_rmap(rmapp);
 906                 hptep[0] &= ~HPTE_V_HVLOCK;
 907         }
 908         return 0;
 909 }
 910
 911 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
 912 {
 913         if (kvm->arch.using_mmu_notifiers)
 914                 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
 915         return 0;
 916 }
 917
 918 int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end)
 919 {
 920         if (kvm->arch.using_mmu_notifiers)
 921                 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp);
 922         return 0;
 923 }
 924
 925 void kvmppc_core_flush_memslot(struct kvm *kvm, struct kvm_memory_slot *memslot)
 926 {
 927         unsigned long *rmapp;
 928         unsigned long gfn;
 929         unsigned long n;
 930
 931         rmapp = memslot->arch.rmap;
 932         gfn = memslot->base_gfn;
 933         for (n = memslot->npages; n; --n) {
 934                 /*
 935                  * Testing the present bit without locking is OK because
 936                  * the memslot has been marked invalid already, and hence
 937                  * no new HPTEs referencing this page can be created,
 938                  * thus the present bit can't go from 0 to 1.
 939                  */
 940                 if (*rmapp & KVMPPC_RMAP_PRESENT)
 941                         kvm_unmap_rmapp(kvm, rmapp, gfn);
 942                 ++rmapp;
 943                 ++gfn;
 944         }
 945 }
 946
 947 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
 948                          unsigned long gfn)
 949 {
 950         struct revmap_entry *rev = kvm->arch.revmap;
 951         unsigned long head, i, j;
 952         unsigned long *hptep;
 953         int ret = 0;
 954
 955  retry:
 956         lock_rmap(rmapp);
 957         if (*rmapp & KVMPPC_RMAP_REFERENCED) {
 958                 *rmapp &= ~KVMPPC_RMAP_REFERENCED;
 959                 ret = 1;
 960         }
 961         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 962                 unlock_rmap(rmapp);
 963                 return ret;
 964         }
 965
 966         i = head = *rmapp & KVMPPC_RMAP_INDEX;
 967         do {
 968                 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
 969                 j = rev[i].forw;
 970
 971                 /* If this HPTE isn't referenced, ignore it */
 972                 if (!(hptep[1] & HPTE_R_R))
 973                         continue;
 974
 975                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 976                         /* unlock rmap before spinning on the HPTE lock */
 977                         unlock_rmap(rmapp);
 978                         while (hptep[0] & HPTE_V_HVLOCK)
 979                                 cpu_relax();
 980                         goto retry;
 981                 }
 982
 983                 /* Now check and modify the HPTE */
 984                 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) {
 985                         kvmppc_clear_ref_hpte(kvm, hptep, i);
 986                         if (!(rev[i].guest_rpte & HPTE_R_R)) {
 987                                 rev[i].guest_rpte |= HPTE_R_R;
 988                                 note_hpte_modification(kvm, &rev[i]);
 989                         }
 990                         ret = 1;
 991                 }
 992                 hptep[0] &= ~HPTE_V_HVLOCK;
 993         } while ((i = j) != head);
 994
 995         unlock_rmap(rmapp);
 996         return ret;
 997 }
 998
 999 int kvm_age_hva(struct kvm *kvm, unsigned long hva)
1000 {
1001         if (!kvm->arch.using_mmu_notifiers)
1002                 return 0;
1003         return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
1004 }
1005
1006 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
1007                               unsigned long gfn)
1008 {
1009         struct revmap_entry *rev = kvm->arch.revmap;
1010         unsigned long head, i, j;
1011         unsigned long *hp;
1012         int ret = 1;
1013
1014         if (*rmapp & KVMPPC_RMAP_REFERENCED)
1015                 return 1;
1016
1017         lock_rmap(rmapp);
1018         if (*rmapp & KVMPPC_RMAP_REFERENCED)
1019                 goto out;
1020
1021         if (*rmapp & KVMPPC_RMAP_PRESENT) {
1022                 i = head = *rmapp & KVMPPC_RMAP_INDEX;
1023                 do {
1024                         hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4));
1025                         j = rev[i].forw;
1026                         if (hp[1] & HPTE_R_R)
1027                                 goto out;
1028                 } while ((i = j) != head);
1029         }
1030         ret = 0;
1031
1032  out:
1033         unlock_rmap(rmapp);
1034         return ret;
1035 }
1036
1037 int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
1038 {
1039         if (!kvm->arch.using_mmu_notifiers)
1040                 return 0;
1041         return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp);
1042 }
1043
1044 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
1045 {
1046         if (!kvm->arch.using_mmu_notifiers)
1047                 return;
1048         kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
1049 }
1050
1051 static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp)
1052 {
1053         struct revmap_entry *rev = kvm->arch.revmap;
1054         unsigned long head, i, j;
1055         unsigned long *hptep;
1056         int ret = 0;
1057
1058  retry:
1059         lock_rmap(rmapp);
1060         if (*rmapp & KVMPPC_RMAP_CHANGED) {
1061                 *rmapp &= ~KVMPPC_RMAP_CHANGED;
1062                 ret = 1;
1063         }
1064         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
1065                 unlock_rmap(rmapp);
1066                 return ret;
1067         }
1068
1069         i = head = *rmapp & KVMPPC_RMAP_INDEX;
1070         do {
1071                 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
1072                 j = rev[i].forw;
1073
1074                 if (!(hptep[1] & HPTE_R_C))
1075                         continue;
1076
1077                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
1078                         /* unlock rmap before spinning on the HPTE lock */
1079                         unlock_rmap(rmapp);
1080                         while (hptep[0] & HPTE_V_HVLOCK)
1081                                 cpu_relax();
1082                         goto retry;
1083                 }
1084
1085                 /* Now check and modify the HPTE */
1086                 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) {
1087                         /* need to make it temporarily absent to clear C */
1088                         hptep[0] |= HPTE_V_ABSENT;
1089                         kvmppc_invalidate_hpte(kvm, hptep, i);
1090                         hptep[1] &= ~HPTE_R_C;
1091                         eieio();
1092                         hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
1093                         if (!(rev[i].guest_rpte & HPTE_R_C)) {
1094                                 rev[i].guest_rpte |= HPTE_R_C;
1095                                 note_hpte_modification(kvm, &rev[i]);
1096                         }
1097                         ret = 1;
1098                 }
1099                 hptep[0] &= ~HPTE_V_HVLOCK;
1100         } while ((i = j) != head);
1101
1102         unlock_rmap(rmapp);
1103         return ret;
1104 }
1105
1106 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa,
1107                               struct kvm_memory_slot *memslot,
1108                               unsigned long *map)
1109 {
1110         unsigned long gfn;
1111
1112         if (!vpa->dirty || !vpa->pinned_addr)
1113                 return;
1114         gfn = vpa->gpa >> PAGE_SHIFT;
1115         if (gfn < memslot->base_gfn ||
1116             gfn >= memslot->base_gfn + memslot->npages)
1117                 return;
1118
1119         vpa->dirty = false;
1120         if (map)
1121                 __set_bit_le(gfn - memslot->base_gfn, map);
1122 }
1123
1124 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot,
1125                              unsigned long *map)
1126 {
1127         unsigned long i;
1128         unsigned long *rmapp;
1129         struct kvm_vcpu *vcpu;
1130
1131         preempt_disable();
1132         rmapp = memslot->arch.rmap;
1133         for (i = 0; i < memslot->npages; ++i) {
1134                 if (kvm_test_clear_dirty(kvm, rmapp) && map)
1135                         __set_bit_le(i, map);
1136                 ++rmapp;
1137         }
1138
1139         /* Harvest dirty bits from VPA and DTL updates */
1140         /* Note: we never modify the SLB shadow buffer areas */
1141         kvm_for_each_vcpu(i, vcpu, kvm) {
1142                 spin_lock(&vcpu->arch.vpa_update_lock);
1143                 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map);
1144                 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map);
1145                 spin_unlock(&vcpu->arch.vpa_update_lock);
1146         }
1147         preempt_enable();
1148         return 0;
1149 }
1150
1151 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
1152                             unsigned long *nb_ret)
1153 {
1154         struct kvm_memory_slot *memslot;
1155         unsigned long gfn = gpa >> PAGE_SHIFT;
1156         struct page *page, *pages[1];
1157         int npages;
1158         unsigned long hva, offset;
1159         unsigned long pa;
1160         unsigned long *physp;
1161         int srcu_idx;
1162
1163         srcu_idx = srcu_read_lock(&kvm->srcu);
1164         memslot = gfn_to_memslot(kvm, gfn);
1165         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
1166                 goto err;
1167         if (!kvm->arch.using_mmu_notifiers) {
1168                 physp = memslot->arch.slot_phys;
1169                 if (!physp)
1170                         goto err;
1171                 physp += gfn - memslot->base_gfn;
1172                 pa = *physp;
1173                 if (!pa) {
1174                         if (kvmppc_get_guest_page(kvm, gfn, memslot,
1175                                                   PAGE_SIZE) < 0)
1176                                 goto err;
1177                         pa = *physp;
1178                 }
1179                 page = pfn_to_page(pa >> PAGE_SHIFT);
1180                 get_page(page);
1181         } else {
1182                 hva = gfn_to_hva_memslot(memslot, gfn);
1183                 npages = get_user_pages_fast(hva, 1, 1, pages);
1184                 if (npages < 1)
1185                         goto err;
1186                 page = pages[0];
1187         }
1188         srcu_read_unlock(&kvm->srcu, srcu_idx);
1189
1190         offset = gpa & (PAGE_SIZE - 1);
1191         if (nb_ret)
1192                 *nb_ret = PAGE_SIZE - offset;
1193         return page_address(page) + offset;
1194
1195  err:
1196         srcu_read_unlock(&kvm->srcu, srcu_idx);
1197         return NULL;
1198 }
1199
1200 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
1201                              bool dirty)
1202 {
1203         struct page *page = virt_to_page(va);
1204         struct kvm_memory_slot *memslot;
1205         unsigned long gfn;
1206         unsigned long *rmap;
1207         int srcu_idx;
1208
1209         put_page(page);
1210
1211         if (!dirty || !kvm->arch.using_mmu_notifiers)
1212                 return;
1213
1214         /* We need to mark this page dirty in the rmap chain */
1215         gfn = gpa >> PAGE_SHIFT;
1216         srcu_idx = srcu_read_lock(&kvm->srcu);
1217         memslot = gfn_to_memslot(kvm, gfn);
1218         if (memslot) {
1219                 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
1220                 lock_rmap(rmap);
1221                 *rmap |= KVMPPC_RMAP_CHANGED;
1222                 unlock_rmap(rmap);
1223         }
1224         srcu_read_unlock(&kvm->srcu, srcu_idx);
1225 }
1226
1227 /*
1228  * Functions for reading and writing the hash table via reads and
1229  * writes on a file descriptor.
1230  *
1231  * Reads return the guest view of the hash table, which has to be
1232  * pieced together from the real hash table and the guest_rpte
1233  * values in the revmap array.
1234  *
1235  * On writes, each HPTE written is considered in turn, and if it
1236  * is valid, it is written to the HPT as if an H_ENTER with the
1237  * exact flag set was done.  When the invalid count is non-zero
1238  * in the header written to the stream, the kernel will make
1239  * sure that that many HPTEs are invalid, and invalidate them
1240  * if not.
1241  */
1242
1243 struct kvm_htab_ctx {
1244         unsigned long   index;
1245         unsigned long   flags;
1246         struct kvm      *kvm;
1247         int             first_pass;
1248 };
1249
1250 #define HPTE_SIZE       (2 * sizeof(unsigned long))
1251
1252 /*
1253  * Returns 1 if this HPT entry has been modified or has pending
1254  * R/C bit changes.
1255  */
1256 static int hpte_dirty(struct revmap_entry *revp, unsigned long *hptp)
1257 {
1258         unsigned long rcbits_unset;
1259
1260         if (revp->guest_rpte & HPTE_GR_MODIFIED)
1261                 return 1;
1262
1263         /* Also need to consider changes in reference and changed bits */
1264         rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1265         if ((hptp[0] & HPTE_V_VALID) && (hptp[1] & rcbits_unset))
1266                 return 1;
1267
1268         return 0;
1269 }
1270
1271 static long record_hpte(unsigned long flags, unsigned long *hptp,
1272                         unsigned long *hpte, struct revmap_entry *revp,
1273                         int want_valid, int first_pass)
1274 {
1275         unsigned long v, r;
1276         unsigned long rcbits_unset;
1277         int ok = 1;
1278         int valid, dirty;
1279
1280         /* Unmodified entries are uninteresting except on the first pass */
1281         dirty = hpte_dirty(revp, hptp);
1282         if (!first_pass && !dirty)
1283                 return 0;
1284
1285         valid = 0;
1286         if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1287                 valid = 1;
1288                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1289                     !(hptp[0] & HPTE_V_BOLTED))
1290                         valid = 0;
1291         }
1292         if (valid != want_valid)
1293                 return 0;
1294
1295         v = r = 0;
1296         if (valid || dirty) {
1297                 /* lock the HPTE so it's stable and read it */
1298                 preempt_disable();
1299                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1300                         cpu_relax();
1301                 v = hptp[0];
1302
1303                 /* re-evaluate valid and dirty from synchronized HPTE value */
1304                 valid = !!(v & HPTE_V_VALID);
1305                 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1306
1307                 /* Harvest R and C into guest view if necessary */
1308                 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1309                 if (valid && (rcbits_unset & hptp[1])) {
1310                         revp->guest_rpte |= (hptp[1] & (HPTE_R_R | HPTE_R_C)) |
1311                                 HPTE_GR_MODIFIED;
1312                         dirty = 1;
1313                 }
1314
1315                 if (v & HPTE_V_ABSENT) {
1316                         v &= ~HPTE_V_ABSENT;
1317                         v |= HPTE_V_VALID;
1318                         valid = 1;
1319                 }
1320                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1321                         valid = 0;
1322
1323                 r = revp->guest_rpte;
1324                 /* only clear modified if this is the right sort of entry */
1325                 if (valid == want_valid && dirty) {
1326                         r &= ~HPTE_GR_MODIFIED;
1327                         revp->guest_rpte = r;
1328                 }
1329                 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory");
1330                 hptp[0] &= ~HPTE_V_HVLOCK;
1331                 preempt_enable();
1332                 if (!(valid == want_valid && (first_pass || dirty)))
1333                         ok = 0;
1334         }
1335         hpte[0] = v;
1336         hpte[1] = r;
1337         return ok;
1338 }
1339
1340 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1341                              size_t count, loff_t *ppos)
1342 {
1343         struct kvm_htab_ctx *ctx = file->private_data;
1344         struct kvm *kvm = ctx->kvm;
1345         struct kvm_get_htab_header hdr;
1346         unsigned long *hptp;
1347         struct revmap_entry *revp;
1348         unsigned long i, nb, nw;
1349         unsigned long __user *lbuf;
1350         struct kvm_get_htab_header __user *hptr;
1351         unsigned long flags;
1352         int first_pass;
1353         unsigned long hpte[2];
1354
1355         if (!access_ok(VERIFY_WRITE, buf, count))
1356                 return -EFAULT;
1357
1358         first_pass = ctx->first_pass;
1359         flags = ctx->flags;
1360
1361         i = ctx->index;
1362         hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1363         revp = kvm->arch.revmap + i;
1364         lbuf = (unsigned long __user *)buf;
1365
1366         nb = 0;
1367         while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1368                 /* Initialize header */
1369                 hptr = (struct kvm_get_htab_header __user *)buf;
1370                 hdr.n_valid = 0;
1371                 hdr.n_invalid = 0;
1372                 nw = nb;
1373                 nb += sizeof(hdr);
1374                 lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1375
1376                 /* Skip uninteresting entries, i.e. clean on not-first pass */
1377                 if (!first_pass) {
1378                         while (i < kvm->arch.hpt_npte &&
1379                                !hpte_dirty(revp, hptp)) {
1380                                 ++i;
1381                                 hptp += 2;
1382                                 ++revp;
1383                         }
1384                 }
1385                 hdr.index = i;
1386
1387                 /* Grab a series of valid entries */
1388                 while (i < kvm->arch.hpt_npte &&
1389                        hdr.n_valid < 0xffff &&
1390                        nb + HPTE_SIZE < count &&
1391                        record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1392                         /* valid entry, write it out */
1393                         ++hdr.n_valid;
1394                         if (__put_user(hpte[0], lbuf) ||
1395                             __put_user(hpte[1], lbuf + 1))
1396                                 return -EFAULT;
1397                         nb += HPTE_SIZE;
1398                         lbuf += 2;
1399                         ++i;
1400                         hptp += 2;
1401                         ++revp;
1402                 }
1403                 /* Now skip invalid entries while we can */
1404                 while (i < kvm->arch.hpt_npte &&
1405                        hdr.n_invalid < 0xffff &&
1406                        record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1407                         /* found an invalid entry */
1408                         ++hdr.n_invalid;
1409                         ++i;
1410                         hptp += 2;
1411                         ++revp;
1412                 }
1413
1414                 if (hdr.n_valid || hdr.n_invalid) {
1415                         /* write back the header */
1416                         if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1417                                 return -EFAULT;
1418                         nw = nb;
1419                         buf = (char __user *)lbuf;
1420                 } else {
1421                         nb = nw;
1422                 }
1423
1424                 /* Check if we've wrapped around the hash table */
1425                 if (i >= kvm->arch.hpt_npte) {
1426                         i = 0;
1427                         ctx->first_pass = 0;
1428                         break;
1429                 }
1430         }
1431
1432         ctx->index = i;
1433
1434         return nb;
1435 }
1436
1437 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1438                               size_t count, loff_t *ppos)
1439 {
1440         struct kvm_htab_ctx *ctx = file->private_data;
1441         struct kvm *kvm = ctx->kvm;
1442         struct kvm_get_htab_header hdr;
1443         unsigned long i, j;
1444         unsigned long v, r;
1445         unsigned long __user *lbuf;
1446         unsigned long *hptp;
1447         unsigned long tmp[2];
1448         ssize_t nb;
1449         long int err, ret;
1450         int rma_setup;
1451
1452         if (!access_ok(VERIFY_READ, buf, count))
1453                 return -EFAULT;
1454
1455         /* lock out vcpus from running while we're doing this */
1456         mutex_lock(&kvm->lock);
1457         rma_setup = kvm->arch.rma_setup_done;
1458         if (rma_setup) {
1459                 kvm->arch.rma_setup_done = 0;   /* temporarily */
1460                 /* order rma_setup_done vs. vcpus_running */
1461                 smp_mb();
1462                 if (atomic_read(&kvm->arch.vcpus_running)) {
1463                         kvm->arch.rma_setup_done = 1;
1464                         mutex_unlock(&kvm->lock);
1465                         return -EBUSY;
1466                 }
1467         }
1468
1469         err = 0;
1470         for (nb = 0; nb + sizeof(hdr) <= count; ) {
1471                 err = -EFAULT;
1472                 if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1473                         break;
1474
1475                 err = 0;
1476                 if (nb + hdr.n_valid * HPTE_SIZE > count)
1477                         break;
1478
1479                 nb += sizeof(hdr);
1480                 buf += sizeof(hdr);
1481
1482                 err = -EINVAL;
1483                 i = hdr.index;
1484                 if (i >= kvm->arch.hpt_npte ||
1485                     i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte)
1486                         break;
1487
1488                 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1489                 lbuf = (unsigned long __user *)buf;
1490                 for (j = 0; j < hdr.n_valid; ++j) {
1491                         err = -EFAULT;
1492                         if (__get_user(v, lbuf) || __get_user(r, lbuf + 1))
1493                                 goto out;
1494                         err = -EINVAL;
1495                         if (!(v & HPTE_V_VALID))
1496                                 goto out;
1497                         lbuf += 2;
1498                         nb += HPTE_SIZE;
1499
1500                         if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT))
1501                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1502                         err = -EIO;
1503                         ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1504                                                          tmp);
1505                         if (ret != H_SUCCESS) {
1506                                 pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
1507                                        "r=%lx\n", ret, i, v, r);
1508                                 goto out;
1509                         }
1510                         if (!rma_setup && is_vrma_hpte(v)) {
1511                                 unsigned long psize = hpte_page_size(v, r);
1512                                 unsigned long senc = slb_pgsize_encoding(psize);
1513                                 unsigned long lpcr;
1514
1515                                 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1516                                         (VRMA_VSID << SLB_VSID_SHIFT_1T);
1517                                 lpcr = kvm->arch.lpcr & ~LPCR_VRMASD;
1518                                 lpcr |= senc << (LPCR_VRMASD_SH - 4);
1519                                 kvm->arch.lpcr = lpcr;
1520                                 rma_setup = 1;
1521                         }
1522                         ++i;
1523                         hptp += 2;
1524                 }
1525
1526                 for (j = 0; j < hdr.n_invalid; ++j) {
1527                         if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT))
1528                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1529                         ++i;
1530                         hptp += 2;
1531                 }
1532                 err = 0;
1533         }
1534
1535  out:
1536         /* Order HPTE updates vs. rma_setup_done */
1537         smp_wmb();
1538         kvm->arch.rma_setup_done = rma_setup;
1539         mutex_unlock(&kvm->lock);
1540
1541         if (err)
1542                 return err;
1543         return nb;
1544 }
1545
1546 static int kvm_htab_release(struct inode *inode, struct file *filp)
1547 {
1548         struct kvm_htab_ctx *ctx = filp->private_data;
1549
1550         filp->private_data = NULL;
1551         if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1552                 atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1553         kvm_put_kvm(ctx->kvm);
1554         kfree(ctx);
1555         return 0;
1556 }
1557
1558 static const struct file_operations kvm_htab_fops = {
1559         .read           = kvm_htab_read,
1560         .write          = kvm_htab_write,
1561         .llseek         = default_llseek,
1562         .release        = kvm_htab_release,
1563 };
1564
1565 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1566 {
1567         int ret;
1568         struct kvm_htab_ctx *ctx;
1569         int rwflag;
1570
1571         /* reject flags we don't recognize */
1572         if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1573                 return -EINVAL;
1574         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1575         if (!ctx)
1576                 return -ENOMEM;
1577         kvm_get_kvm(kvm);
1578         ctx->kvm = kvm;
1579         ctx->index = ghf->start_index;
1580         ctx->flags = ghf->flags;
1581         ctx->first_pass = 1;
1582
1583         rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1584         ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag);
1585         if (ret < 0) {
1586                 kvm_put_kvm(kvm);
1587                 return ret;
1588         }
1589
1590         if (rwflag == O_RDONLY) {
1591                 mutex_lock(&kvm->slots_lock);
1592                 atomic_inc(&kvm->arch.hpte_mod_interest);
1593                 /* make sure kvmppc_do_h_enter etc. see the increment */
1594                 synchronize_srcu_expedited(&kvm->srcu);
1595                 mutex_unlock(&kvm->slots_lock);
1596         }
1597
1598         return ret;
1599 }
1600
1601 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
1602 {
1603         struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
1604
1605         if (cpu_has_feature(CPU_FTR_ARCH_206))
1606                 vcpu->arch.slb_nr = 32;         /* POWER7 */
1607         else
1608                 vcpu->arch.slb_nr = 64;
1609
1610         mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
1611         mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
1612
1613         vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
1614 }