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 #include "book3s_hv_cma.h"
  41
  42 /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */
  43 #define MAX_LPID_970    63
  44
  45 /* Power architecture requires HPT is at least 256kB */
  46 #define PPC_MIN_HPT_ORDER       18
  47
  48 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
  49                                 long pte_index, unsigned long pteh,
  50                                 unsigned long ptel, unsigned long *pte_idx_ret);
  51 static void kvmppc_rmap_reset(struct kvm *kvm);
  52
  53 long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
  54 {
  55         unsigned long hpt = 0;
  56         struct revmap_entry *rev;
  57         struct page *page = NULL;
  58         long order = KVM_DEFAULT_HPT_ORDER;
  59
  60         if (htab_orderp) {
  61                 order = *htab_orderp;
  62                 if (order < PPC_MIN_HPT_ORDER)
  63                         order = PPC_MIN_HPT_ORDER;
  64         }
  65
  66         kvm->arch.hpt_cma_alloc = 0;
  67         VM_BUG_ON(order < KVM_CMA_CHUNK_ORDER);
  68         page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT));
  69         if (page) {
  70                 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
  71                 kvm->arch.hpt_cma_alloc = 1;
  72         }
  73
  74         /* Lastly try successively smaller sizes from the page allocator */
  75         while (!hpt && order > PPC_MIN_HPT_ORDER) {
  76                 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
  77                                        __GFP_NOWARN, order - PAGE_SHIFT);
  78                 if (!hpt)
  79                         --order;
  80         }
  81
  82         if (!hpt)
  83                 return -ENOMEM;
  84
  85         kvm->arch.hpt_virt = hpt;
  86         kvm->arch.hpt_order = order;
  87         /* HPTEs are 2**4 bytes long */
  88         kvm->arch.hpt_npte = 1ul << (order - 4);
  89         /* 128 (2**7) bytes in each HPTEG */
  90         kvm->arch.hpt_mask = (1ul << (order - 7)) - 1;
  91
  92         /* Allocate reverse map array */
  93         rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte);
  94         if (!rev) {
  95                 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
  96                 goto out_freehpt;
  97         }
  98         kvm->arch.revmap = rev;
  99         kvm->arch.sdr1 = __pa(hpt) | (order - 18);
 100
 101         pr_info("KVM guest htab at %lx (order %ld), LPID %x\n",
 102                 hpt, order, kvm->arch.lpid);
 103
 104         if (htab_orderp)
 105                 *htab_orderp = order;
 106         return 0;
 107
 108  out_freehpt:
 109         if (kvm->arch.hpt_cma_alloc)
 110                 kvm_release_hpt(page, 1 << (order - PAGE_SHIFT));
 111         else
 112                 free_pages(hpt, order - PAGE_SHIFT);
 113         return -ENOMEM;
 114 }
 115
 116 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
 117 {
 118         long err = -EBUSY;
 119         long order;
 120
 121         mutex_lock(&kvm->lock);
 122         if (kvm->arch.rma_setup_done) {
 123                 kvm->arch.rma_setup_done = 0;
 124                 /* order rma_setup_done vs. vcpus_running */
 125                 smp_mb();
 126                 if (atomic_read(&kvm->arch.vcpus_running)) {
 127                         kvm->arch.rma_setup_done = 1;
 128                         goto out;
 129                 }
 130         }
 131         if (kvm->arch.hpt_virt) {
 132                 order = kvm->arch.hpt_order;
 133                 /* Set the entire HPT to 0, i.e. invalid HPTEs */
 134                 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order);
 135                 /*
 136                  * Reset all the reverse-mapping chains for all memslots
 137                  */
 138                 kvmppc_rmap_reset(kvm);
 139                 /* Ensure that each vcpu will flush its TLB on next entry. */
 140                 cpumask_setall(&kvm->arch.need_tlb_flush);
 141                 *htab_orderp = order;
 142                 err = 0;
 143         } else {
 144                 err = kvmppc_alloc_hpt(kvm, htab_orderp);
 145                 order = *htab_orderp;
 146         }
 147  out:
 148         mutex_unlock(&kvm->lock);
 149         return err;
 150 }
 151
 152 void kvmppc_free_hpt(struct kvm *kvm)
 153 {
 154         kvmppc_free_lpid(kvm->arch.lpid);
 155         vfree(kvm->arch.revmap);
 156         if (kvm->arch.hpt_cma_alloc)
 157                 kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt),
 158                                 1 << (kvm->arch.hpt_order - PAGE_SHIFT));
 159         else
 160                 free_pages(kvm->arch.hpt_virt,
 161                            kvm->arch.hpt_order - PAGE_SHIFT);
 162 }
 163
 164 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
 165 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
 166 {
 167         return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
 168 }
 169
 170 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
 171 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
 172 {
 173         return (pgsize == 0x10000) ? 0x1000 : 0;
 174 }
 175
 176 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
 177                      unsigned long porder)
 178 {
 179         unsigned long i;
 180         unsigned long npages;
 181         unsigned long hp_v, hp_r;
 182         unsigned long addr, hash;
 183         unsigned long psize;
 184         unsigned long hp0, hp1;
 185         unsigned long idx_ret;
 186         long ret;
 187         struct kvm *kvm = vcpu->kvm;
 188
 189         psize = 1ul << porder;
 190         npages = memslot->npages >> (porder - PAGE_SHIFT);
 191
 192         /* VRMA can't be > 1TB */
 193         if (npages > 1ul << (40 - porder))
 194                 npages = 1ul << (40 - porder);
 195         /* Can't use more than 1 HPTE per HPTEG */
 196         if (npages > kvm->arch.hpt_mask + 1)
 197                 npages = kvm->arch.hpt_mask + 1;
 198
 199         hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
 200                 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
 201         hp1 = hpte1_pgsize_encoding(psize) |
 202                 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
 203
 204         for (i = 0; i < npages; ++i) {
 205                 addr = i << porder;
 206                 /* can't use hpt_hash since va > 64 bits */
 207                 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask;
 208                 /*
 209                  * We assume that the hash table is empty and no
 210                  * vcpus are using it at this stage.  Since we create
 211                  * at most one HPTE per HPTEG, we just assume entry 7
 212                  * is available and use it.
 213                  */
 214                 hash = (hash << 3) + 7;
 215                 hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
 216                 hp_r = hp1 | addr;
 217                 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
 218                                                  &idx_ret);
 219                 if (ret != H_SUCCESS) {
 220                         pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
 221                                addr, ret);
 222                         break;
 223                 }
 224         }
 225 }
 226
 227 int kvmppc_mmu_hv_init(void)
 228 {
 229         unsigned long host_lpid, rsvd_lpid;
 230
 231         if (!cpu_has_feature(CPU_FTR_HVMODE))
 232                 return -EINVAL;
 233
 234         /* POWER7 has 10-bit LPIDs, PPC970 and e500mc have 6-bit LPIDs */
 235         if (cpu_has_feature(CPU_FTR_ARCH_206)) {
 236                 host_lpid = mfspr(SPRN_LPID);   /* POWER7 */
 237                 rsvd_lpid = LPID_RSVD;
 238         } else {
 239                 host_lpid = 0;                  /* PPC970 */
 240                 rsvd_lpid = MAX_LPID_970;
 241         }
 242
 243         kvmppc_init_lpid(rsvd_lpid + 1);
 244
 245         kvmppc_claim_lpid(host_lpid);
 246         /* rsvd_lpid is reserved for use in partition switching */
 247         kvmppc_claim_lpid(rsvd_lpid);
 248
 249         return 0;
 250 }
 251
 252 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
 253 {
 254         unsigned long msr = vcpu->arch.intr_msr;
 255
 256         /* If transactional, change to suspend mode on IRQ delivery */
 257         if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
 258                 msr |= MSR_TS_S;
 259         else
 260                 msr |= vcpu->arch.shregs.msr & MSR_TS_MASK;
 261         kvmppc_set_msr(vcpu, msr);
 262 }
 263
 264 /*
 265  * This is called to get a reference to a guest page if there isn't
 266  * one already in the memslot->arch.slot_phys[] array.
 267  */
 268 static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn,
 269                                   struct kvm_memory_slot *memslot,
 270                                   unsigned long psize)
 271 {
 272         unsigned long start;
 273         long np, err;
 274         struct page *page, *hpage, *pages[1];
 275         unsigned long s, pgsize;
 276         unsigned long *physp;
 277         unsigned int is_io, got, pgorder;
 278         struct vm_area_struct *vma;
 279         unsigned long pfn, i, npages;
 280
 281         physp = memslot->arch.slot_phys;
 282         if (!physp)
 283                 return -EINVAL;
 284         if (physp[gfn - memslot->base_gfn])
 285                 return 0;
 286
 287         is_io = 0;
 288         got = 0;
 289         page = NULL;
 290         pgsize = psize;
 291         err = -EINVAL;
 292         start = gfn_to_hva_memslot(memslot, gfn);
 293
 294         /* Instantiate and get the page we want access to */
 295         np = get_user_pages_fast(start, 1, 1, pages);
 296         if (np != 1) {
 297                 /* Look up the vma for the page */
 298                 down_read(&current->mm->mmap_sem);
 299                 vma = find_vma(current->mm, start);
 300                 if (!vma || vma->vm_start > start ||
 301                     start + psize > vma->vm_end ||
 302                     !(vma->vm_flags & VM_PFNMAP))
 303                         goto up_err;
 304                 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
 305                 pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
 306                 /* check alignment of pfn vs. requested page size */
 307                 if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1)))
 308                         goto up_err;
 309                 up_read(&current->mm->mmap_sem);
 310
 311         } else {
 312                 page = pages[0];
 313                 got = KVMPPC_GOT_PAGE;
 314
 315                 /* See if this is a large page */
 316                 s = PAGE_SIZE;
 317                 if (PageHuge(page)) {
 318                         hpage = compound_head(page);
 319                         s <<= compound_order(hpage);
 320                         /* Get the whole large page if slot alignment is ok */
 321                         if (s > psize && slot_is_aligned(memslot, s) &&
 322                             !(memslot->userspace_addr & (s - 1))) {
 323                                 start &= ~(s - 1);
 324                                 pgsize = s;
 325                                 get_page(hpage);
 326                                 put_page(page);
 327                                 page = hpage;
 328                         }
 329                 }
 330                 if (s < psize)
 331                         goto out;
 332                 pfn = page_to_pfn(page);
 333         }
 334
 335         npages = pgsize >> PAGE_SHIFT;
 336         pgorder = __ilog2(npages);
 337         physp += (gfn - memslot->base_gfn) & ~(npages - 1);
 338         spin_lock(&kvm->arch.slot_phys_lock);
 339         for (i = 0; i < npages; ++i) {
 340                 if (!physp[i]) {
 341                         physp[i] = ((pfn + i) << PAGE_SHIFT) +
 342                                 got + is_io + pgorder;
 343                         got = 0;
 344                 }
 345         }
 346         spin_unlock(&kvm->arch.slot_phys_lock);
 347         err = 0;
 348
 349  out:
 350         if (got)
 351                 put_page(page);
 352         return err;
 353
 354  up_err:
 355         up_read(&current->mm->mmap_sem);
 356         return err;
 357 }
 358
 359 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
 360                                 long pte_index, unsigned long pteh,
 361                                 unsigned long ptel, unsigned long *pte_idx_ret)
 362 {
 363         unsigned long psize, gpa, gfn;
 364         struct kvm_memory_slot *memslot;
 365         long ret;
 366
 367         if (kvm->arch.using_mmu_notifiers)
 368                 goto do_insert;
 369
 370         psize = hpte_page_size(pteh, ptel);
 371         if (!psize)
 372                 return H_PARAMETER;
 373
 374         pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID);
 375
 376         /* Find the memslot (if any) for this address */
 377         gpa = (ptel & HPTE_R_RPN) & ~(psize - 1);
 378         gfn = gpa >> PAGE_SHIFT;
 379         memslot = gfn_to_memslot(kvm, gfn);
 380         if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) {
 381                 if (!slot_is_aligned(memslot, psize))
 382                         return H_PARAMETER;
 383                 if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0)
 384                         return H_PARAMETER;
 385         }
 386
 387  do_insert:
 388         /* Protect linux PTE lookup from page table destruction */
 389         rcu_read_lock_sched();  /* this disables preemption too */
 390         ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
 391                                 current->mm->pgd, false, pte_idx_ret);
 392         rcu_read_unlock_sched();
 393         if (ret == H_TOO_HARD) {
 394                 /* this can't happen */
 395                 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
 396                 ret = H_RESOURCE;       /* or something */
 397         }
 398         return ret;
 399
 400 }
 401
 402 /*
 403  * We come here on a H_ENTER call from the guest when we are not
 404  * using mmu notifiers and we don't have the requested page pinned
 405  * already.
 406  */
 407 long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
 408                              long pte_index, unsigned long pteh,
 409                              unsigned long ptel)
 410 {
 411         return kvmppc_virtmode_do_h_enter(vcpu->kvm, flags, pte_index,
 412                                           pteh, ptel, &vcpu->arch.gpr[4]);
 413 }
 414
 415 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
 416                                                          gva_t eaddr)
 417 {
 418         u64 mask;
 419         int i;
 420
 421         for (i = 0; i < vcpu->arch.slb_nr; i++) {
 422                 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
 423                         continue;
 424
 425                 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
 426                         mask = ESID_MASK_1T;
 427                 else
 428                         mask = ESID_MASK;
 429
 430                 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
 431                         return &vcpu->arch.slb[i];
 432         }
 433         return NULL;
 434 }
 435
 436 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
 437                         unsigned long ea)
 438 {
 439         unsigned long ra_mask;
 440
 441         ra_mask = hpte_page_size(v, r) - 1;
 442         return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
 443 }
 444
 445 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 446                         struct kvmppc_pte *gpte, bool data, bool iswrite)
 447 {
 448         struct kvm *kvm = vcpu->kvm;
 449         struct kvmppc_slb *slbe;
 450         unsigned long slb_v;
 451         unsigned long pp, key;
 452         unsigned long v, gr;
 453         __be64 *hptep;
 454         int index;
 455         int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
 456
 457         /* Get SLB entry */
 458         if (virtmode) {
 459                 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
 460                 if (!slbe)
 461                         return -EINVAL;
 462                 slb_v = slbe->origv;
 463         } else {
 464                 /* real mode access */
 465                 slb_v = vcpu->kvm->arch.vrma_slb_v;
 466         }
 467
 468         preempt_disable();
 469         /* Find the HPTE in the hash table */
 470         index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
 471                                          HPTE_V_VALID | HPTE_V_ABSENT);
 472         if (index < 0) {
 473                 preempt_enable();
 474                 return -ENOENT;
 475         }
 476         hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4));
 477         v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
 478         gr = kvm->arch.revmap[index].guest_rpte;
 479
 480         /* Unlock the HPTE */
 481         asm volatile("lwsync" : : : "memory");
 482         hptep[0] = cpu_to_be64(v);
 483         preempt_enable();
 484
 485         gpte->eaddr = eaddr;
 486         gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
 487
 488         /* Get PP bits and key for permission check */
 489         pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
 490         key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
 491         key &= slb_v;
 492
 493         /* Calculate permissions */
 494         gpte->may_read = hpte_read_permission(pp, key);
 495         gpte->may_write = hpte_write_permission(pp, key);
 496         gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
 497
 498         /* Storage key permission check for POWER7 */
 499         if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) {
 500                 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
 501                 if (amrfield & 1)
 502                         gpte->may_read = 0;
 503                 if (amrfield & 2)
 504                         gpte->may_write = 0;
 505         }
 506
 507         /* Get the guest physical address */
 508         gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
 509         return 0;
 510 }
 511
 512 /*
 513  * Quick test for whether an instruction is a load or a store.
 514  * If the instruction is a load or a store, then this will indicate
 515  * which it is, at least on server processors.  (Embedded processors
 516  * have some external PID instructions that don't follow the rule
 517  * embodied here.)  If the instruction isn't a load or store, then
 518  * this doesn't return anything useful.
 519  */
 520 static int instruction_is_store(unsigned int instr)
 521 {
 522         unsigned int mask;
 523
 524         mask = 0x10000000;
 525         if ((instr & 0xfc000000) == 0x7c000000)
 526                 mask = 0x100;           /* major opcode 31 */
 527         return (instr & mask) != 0;
 528 }
 529
 530 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
 531                                   unsigned long gpa, gva_t ea, int is_store)
 532 {
 533         u32 last_inst;
 534
 535         /*
 536          * If we fail, we just return to the guest and try executing it again.
 537          */
 538         if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
 539                 EMULATE_DONE)
 540                 return RESUME_GUEST;
 541
 542         /*
 543          * WARNING: We do not know for sure whether the instruction we just
 544          * read from memory is the same that caused the fault in the first
 545          * place.  If the instruction we read is neither an load or a store,
 546          * then it can't access memory, so we don't need to worry about
 547          * enforcing access permissions.  So, assuming it is a load or
 548          * store, we just check that its direction (load or store) is
 549          * consistent with the original fault, since that's what we
 550          * checked the access permissions against.  If there is a mismatch
 551          * we just return and retry the instruction.
 552          */
 553
 554         if (instruction_is_store(last_inst) != !!is_store)
 555                 return RESUME_GUEST;
 556
 557         /*
 558          * Emulated accesses are emulated by looking at the hash for
 559          * translation once, then performing the access later. The
 560          * translation could be invalidated in the meantime in which
 561          * point performing the subsequent memory access on the old
 562          * physical address could possibly be a security hole for the
 563          * guest (but not the host).
 564          *
 565          * This is less of an issue for MMIO stores since they aren't
 566          * globally visible. It could be an issue for MMIO loads to
 567          * a certain extent but we'll ignore it for now.
 568          */
 569
 570         vcpu->arch.paddr_accessed = gpa;
 571         vcpu->arch.vaddr_accessed = ea;
 572         return kvmppc_emulate_mmio(run, vcpu);
 573 }
 574
 575 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 576                                 unsigned long ea, unsigned long dsisr)
 577 {
 578         struct kvm *kvm = vcpu->kvm;
 579         unsigned long hpte[3], r;
 580         __be64 *hptep;
 581         unsigned long mmu_seq, psize, pte_size;
 582         unsigned long gpa_base, gfn_base;
 583         unsigned long gpa, gfn, hva, pfn;
 584         struct kvm_memory_slot *memslot;
 585         unsigned long *rmap;
 586         struct revmap_entry *rev;
 587         struct page *page, *pages[1];
 588         long index, ret, npages;
 589         unsigned long is_io;
 590         unsigned int writing, write_ok;
 591         struct vm_area_struct *vma;
 592         unsigned long rcbits;
 593
 594         /*
 595          * Real-mode code has already searched the HPT and found the
 596          * entry we're interested in.  Lock the entry and check that
 597          * it hasn't changed.  If it has, just return and re-execute the
 598          * instruction.
 599          */
 600         if (ea != vcpu->arch.pgfault_addr)
 601                 return RESUME_GUEST;
 602         index = vcpu->arch.pgfault_index;
 603         hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4));
 604         rev = &kvm->arch.revmap[index];
 605         preempt_disable();
 606         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
 607                 cpu_relax();
 608         hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
 609         hpte[1] = be64_to_cpu(hptep[1]);
 610         hpte[2] = r = rev->guest_rpte;
 611         asm volatile("lwsync" : : : "memory");
 612         hptep[0] = cpu_to_be64(hpte[0]);
 613         preempt_enable();
 614
 615         if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
 616             hpte[1] != vcpu->arch.pgfault_hpte[1])
 617                 return RESUME_GUEST;
 618
 619         /* Translate the logical address and get the page */
 620         psize = hpte_page_size(hpte[0], r);
 621         gpa_base = r & HPTE_R_RPN & ~(psize - 1);
 622         gfn_base = gpa_base >> PAGE_SHIFT;
 623         gpa = gpa_base | (ea & (psize - 1));
 624         gfn = gpa >> PAGE_SHIFT;
 625         memslot = gfn_to_memslot(kvm, gfn);
 626
 627         /* No memslot means it's an emulated MMIO region */
 628         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
 629                 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
 630                                               dsisr & DSISR_ISSTORE);
 631
 632         if (!kvm->arch.using_mmu_notifiers)
 633                 return -EFAULT;         /* should never get here */
 634
 635         /*
 636          * This should never happen, because of the slot_is_aligned()
 637          * check in kvmppc_do_h_enter().
 638          */
 639         if (gfn_base < memslot->base_gfn)
 640                 return -EFAULT;
 641
 642         /* used to check for invalidations in progress */
 643         mmu_seq = kvm->mmu_notifier_seq;
 644         smp_rmb();
 645
 646         is_io = 0;
 647         pfn = 0;
 648         page = NULL;
 649         pte_size = PAGE_SIZE;
 650         writing = (dsisr & DSISR_ISSTORE) != 0;
 651         /* If writing != 0, then the HPTE must allow writing, if we get here */
 652         write_ok = writing;
 653         hva = gfn_to_hva_memslot(memslot, gfn);
 654         npages = get_user_pages_fast(hva, 1, writing, pages);
 655         if (npages < 1) {
 656                 /* Check if it's an I/O mapping */
 657                 down_read(&current->mm->mmap_sem);
 658                 vma = find_vma(current->mm, hva);
 659                 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
 660                     (vma->vm_flags & VM_PFNMAP)) {
 661                         pfn = vma->vm_pgoff +
 662                                 ((hva - vma->vm_start) >> PAGE_SHIFT);
 663                         pte_size = psize;
 664                         is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
 665                         write_ok = vma->vm_flags & VM_WRITE;
 666                 }
 667                 up_read(&current->mm->mmap_sem);
 668                 if (!pfn)
 669                         return -EFAULT;
 670         } else {
 671                 page = pages[0];
 672                 pfn = page_to_pfn(page);
 673                 if (PageHuge(page)) {
 674                         page = compound_head(page);
 675                         pte_size <<= compound_order(page);
 676                 }
 677                 /* if the guest wants write access, see if that is OK */
 678                 if (!writing && hpte_is_writable(r)) {
 679                         unsigned int hugepage_shift;
 680                         pte_t *ptep, pte;
 681
 682                         /*
 683                          * We need to protect against page table destruction
 684                          * while looking up and updating the pte.
 685                          */
 686                         rcu_read_lock_sched();
 687                         ptep = find_linux_pte_or_hugepte(current->mm->pgd,
 688                                                          hva, &hugepage_shift);
 689                         if (ptep) {
 690                                 pte = kvmppc_read_update_linux_pte(ptep, 1,
 691                                                            hugepage_shift);
 692                                 if (pte_write(pte))
 693                                         write_ok = 1;
 694                         }
 695                         rcu_read_unlock_sched();
 696                 }
 697         }
 698
 699         ret = -EFAULT;
 700         if (psize > pte_size)
 701                 goto out_put;
 702
 703         /* Check WIMG vs. the actual page we're accessing */
 704         if (!hpte_cache_flags_ok(r, is_io)) {
 705                 if (is_io)
 706                         return -EFAULT;
 707                 /*
 708                  * Allow guest to map emulated device memory as
 709                  * uncacheable, but actually make it cacheable.
 710                  */
 711                 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
 712         }
 713
 714         /*
 715          * Set the HPTE to point to pfn.
 716          * Since the pfn is at PAGE_SIZE granularity, make sure we
 717          * don't mask out lower-order bits if psize < PAGE_SIZE.
 718          */
 719         if (psize < PAGE_SIZE)
 720                 psize = PAGE_SIZE;
 721         r = (r & ~(HPTE_R_PP0 - psize)) | ((pfn << PAGE_SHIFT) & ~(psize - 1));
 722         if (hpte_is_writable(r) && !write_ok)
 723                 r = hpte_make_readonly(r);
 724         ret = RESUME_GUEST;
 725         preempt_disable();
 726         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
 727                 cpu_relax();
 728         if ((be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK) != hpte[0] ||
 729                 be64_to_cpu(hptep[1]) != hpte[1] ||
 730                 rev->guest_rpte != hpte[2])
 731                 /* HPTE has been changed under us; let the guest retry */
 732                 goto out_unlock;
 733         hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
 734
 735         /* Always put the HPTE in the rmap chain for the page base address */
 736         rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn];
 737         lock_rmap(rmap);
 738
 739         /* Check if we might have been invalidated; let the guest retry if so */
 740         ret = RESUME_GUEST;
 741         if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
 742                 unlock_rmap(rmap);
 743                 goto out_unlock;
 744         }
 745
 746         /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
 747         rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
 748         r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
 749
 750         if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) {
 751                 /* HPTE was previously valid, so we need to invalidate it */
 752                 unlock_rmap(rmap);
 753                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
 754                 kvmppc_invalidate_hpte(kvm, hptep, index);
 755                 /* don't lose previous R and C bits */
 756                 r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
 757         } else {
 758                 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
 759         }
 760
 761         hptep[1] = cpu_to_be64(r);
 762         eieio();
 763         hptep[0] = cpu_to_be64(hpte[0]);
 764         asm volatile("ptesync" : : : "memory");
 765         preempt_enable();
 766         if (page && hpte_is_writable(r))
 767                 SetPageDirty(page);
 768
 769  out_put:
 770         if (page) {
 771                 /*
 772                  * We drop pages[0] here, not page because page might
 773                  * have been set to the head page of a compound, but
 774                  * we have to drop the reference on the correct tail
 775                  * page to match the get inside gup()
 776                  */
 777                 put_page(pages[0]);
 778         }
 779         return ret;
 780
 781  out_unlock:
 782         hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
 783         preempt_enable();
 784         goto out_put;
 785 }
 786
 787 static void kvmppc_rmap_reset(struct kvm *kvm)
 788 {
 789         struct kvm_memslots *slots;
 790         struct kvm_memory_slot *memslot;
 791         int srcu_idx;
 792
 793         srcu_idx = srcu_read_lock(&kvm->srcu);
 794         slots = kvm->memslots;
 795         kvm_for_each_memslot(memslot, slots) {
 796                 /*
 797                  * This assumes it is acceptable to lose reference and
 798                  * change bits across a reset.
 799                  */
 800                 memset(memslot->arch.rmap, 0,
 801                        memslot->npages * sizeof(*memslot->arch.rmap));
 802         }
 803         srcu_read_unlock(&kvm->srcu, srcu_idx);
 804 }
 805
 806 static int kvm_handle_hva_range(struct kvm *kvm,
 807                                 unsigned long start,
 808                                 unsigned long end,
 809                                 int (*handler)(struct kvm *kvm,
 810                                                unsigned long *rmapp,
 811                                                unsigned long gfn))
 812 {
 813         int ret;
 814         int retval = 0;
 815         struct kvm_memslots *slots;
 816         struct kvm_memory_slot *memslot;
 817
 818         slots = kvm_memslots(kvm);
 819         kvm_for_each_memslot(memslot, slots) {
 820                 unsigned long hva_start, hva_end;
 821                 gfn_t gfn, gfn_end;
 822
 823                 hva_start = max(start, memslot->userspace_addr);
 824                 hva_end = min(end, memslot->userspace_addr +
 825                                         (memslot->npages << PAGE_SHIFT));
 826                 if (hva_start >= hva_end)
 827                         continue;
 828                 /*
 829                  * {gfn(page) | page intersects with [hva_start, hva_end)} =
 830                  * {gfn, gfn+1, ..., gfn_end-1}.
 831                  */
 832                 gfn = hva_to_gfn_memslot(hva_start, memslot);
 833                 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
 834
 835                 for (; gfn < gfn_end; ++gfn) {
 836                         gfn_t gfn_offset = gfn - memslot->base_gfn;
 837
 838                         ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn);
 839                         retval |= ret;
 840                 }
 841         }
 842
 843         return retval;
 844 }
 845
 846 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
 847                           int (*handler)(struct kvm *kvm, unsigned long *rmapp,
 848                                          unsigned long gfn))
 849 {
 850         return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
 851 }
 852
 853 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
 854                            unsigned long gfn)
 855 {
 856         struct revmap_entry *rev = kvm->arch.revmap;
 857         unsigned long h, i, j;
 858         __be64 *hptep;
 859         unsigned long ptel, psize, rcbits;
 860
 861         for (;;) {
 862                 lock_rmap(rmapp);
 863                 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 864                         unlock_rmap(rmapp);
 865                         break;
 866                 }
 867
 868                 /*
 869                  * To avoid an ABBA deadlock with the HPTE lock bit,
 870                  * we can't spin on the HPTE lock while holding the
 871                  * rmap chain lock.
 872                  */
 873                 i = *rmapp & KVMPPC_RMAP_INDEX;
 874                 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4));
 875                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 876                         /* unlock rmap before spinning on the HPTE lock */
 877                         unlock_rmap(rmapp);
 878                         while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
 879                                 cpu_relax();
 880                         continue;
 881                 }
 882                 j = rev[i].forw;
 883                 if (j == i) {
 884                         /* chain is now empty */
 885                         *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
 886                 } else {
 887                         /* remove i from chain */
 888                         h = rev[i].back;
 889                         rev[h].forw = j;
 890                         rev[j].back = h;
 891                         rev[i].forw = rev[i].back = i;
 892                         *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
 893                 }
 894
 895                 /* Now check and modify the HPTE */
 896                 ptel = rev[i].guest_rpte;
 897                 psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel);
 898                 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
 899                     hpte_rpn(ptel, psize) == gfn) {
 900                         if (kvm->arch.using_mmu_notifiers)
 901                                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
 902                         kvmppc_invalidate_hpte(kvm, hptep, i);
 903                         /* Harvest R and C */
 904                         rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
 905                         *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
 906                         if (rcbits & ~rev[i].guest_rpte) {
 907                                 rev[i].guest_rpte = ptel | rcbits;
 908                                 note_hpte_modification(kvm, &rev[i]);
 909                         }
 910                 }
 911                 unlock_rmap(rmapp);
 912                 hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
 913         }
 914         return 0;
 915 }
 916
 917 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva)
 918 {
 919         if (kvm->arch.using_mmu_notifiers)
 920                 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
 921         return 0;
 922 }
 923
 924 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end)
 925 {
 926         if (kvm->arch.using_mmu_notifiers)
 927                 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp);
 928         return 0;
 929 }
 930
 931 void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
 932                                   struct kvm_memory_slot *memslot)
 933 {
 934         unsigned long *rmapp;
 935         unsigned long gfn;
 936         unsigned long n;
 937
 938         rmapp = memslot->arch.rmap;
 939         gfn = memslot->base_gfn;
 940         for (n = memslot->npages; n; --n) {
 941                 /*
 942                  * Testing the present bit without locking is OK because
 943                  * the memslot has been marked invalid already, and hence
 944                  * no new HPTEs referencing this page can be created,
 945                  * thus the present bit can't go from 0 to 1.
 946                  */
 947                 if (*rmapp & KVMPPC_RMAP_PRESENT)
 948                         kvm_unmap_rmapp(kvm, rmapp, gfn);
 949                 ++rmapp;
 950                 ++gfn;
 951         }
 952 }
 953
 954 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
 955                          unsigned long gfn)
 956 {
 957         struct revmap_entry *rev = kvm->arch.revmap;
 958         unsigned long head, i, j;
 959         __be64 *hptep;
 960         int ret = 0;
 961
 962  retry:
 963         lock_rmap(rmapp);
 964         if (*rmapp & KVMPPC_RMAP_REFERENCED) {
 965                 *rmapp &= ~KVMPPC_RMAP_REFERENCED;
 966                 ret = 1;
 967         }
 968         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 969                 unlock_rmap(rmapp);
 970                 return ret;
 971         }
 972
 973         i = head = *rmapp & KVMPPC_RMAP_INDEX;
 974         do {
 975                 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4));
 976                 j = rev[i].forw;
 977
 978                 /* If this HPTE isn't referenced, ignore it */
 979                 if (!(be64_to_cpu(hptep[1]) & HPTE_R_R))
 980                         continue;
 981
 982                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 983                         /* unlock rmap before spinning on the HPTE lock */
 984                         unlock_rmap(rmapp);
 985                         while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
 986                                 cpu_relax();
 987                         goto retry;
 988                 }
 989
 990                 /* Now check and modify the HPTE */
 991                 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
 992                     (be64_to_cpu(hptep[1]) & HPTE_R_R)) {
 993                         kvmppc_clear_ref_hpte(kvm, hptep, i);
 994                         if (!(rev[i].guest_rpte & HPTE_R_R)) {
 995                                 rev[i].guest_rpte |= HPTE_R_R;
 996                                 note_hpte_modification(kvm, &rev[i]);
 997                         }
 998                         ret = 1;
 999                 }
1000                 hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
1001         } while ((i = j) != head);
1002
1003         unlock_rmap(rmapp);
1004         return ret;
1005 }
1006
1007 int kvm_age_hva_hv(struct kvm *kvm, unsigned long hva)
1008 {
1009         if (!kvm->arch.using_mmu_notifiers)
1010                 return 0;
1011         return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
1012 }
1013
1014 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
1015                               unsigned long gfn)
1016 {
1017         struct revmap_entry *rev = kvm->arch.revmap;
1018         unsigned long head, i, j;
1019         unsigned long *hp;
1020         int ret = 1;
1021
1022         if (*rmapp & KVMPPC_RMAP_REFERENCED)
1023                 return 1;
1024
1025         lock_rmap(rmapp);
1026         if (*rmapp & KVMPPC_RMAP_REFERENCED)
1027                 goto out;
1028
1029         if (*rmapp & KVMPPC_RMAP_PRESENT) {
1030                 i = head = *rmapp & KVMPPC_RMAP_INDEX;
1031                 do {
1032                         hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4));
1033                         j = rev[i].forw;
1034                         if (be64_to_cpu(hp[1]) & HPTE_R_R)
1035                                 goto out;
1036                 } while ((i = j) != head);
1037         }
1038         ret = 0;
1039
1040  out:
1041         unlock_rmap(rmapp);
1042         return ret;
1043 }
1044
1045 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva)
1046 {
1047         if (!kvm->arch.using_mmu_notifiers)
1048                 return 0;
1049         return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp);
1050 }
1051
1052 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte)
1053 {
1054         if (!kvm->arch.using_mmu_notifiers)
1055                 return;
1056         kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
1057 }
1058
1059 static int vcpus_running(struct kvm *kvm)
1060 {
1061         return atomic_read(&kvm->arch.vcpus_running) != 0;
1062 }
1063
1064 /*
1065  * Returns the number of system pages that are dirty.
1066  * This can be more than 1 if we find a huge-page HPTE.
1067  */
1068 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
1069 {
1070         struct revmap_entry *rev = kvm->arch.revmap;
1071         unsigned long head, i, j;
1072         unsigned long n;
1073         unsigned long v, r;
1074         __be64 *hptep;
1075         int npages_dirty = 0;
1076
1077  retry:
1078         lock_rmap(rmapp);
1079         if (*rmapp & KVMPPC_RMAP_CHANGED) {
1080                 *rmapp &= ~KVMPPC_RMAP_CHANGED;
1081                 npages_dirty = 1;
1082         }
1083         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
1084                 unlock_rmap(rmapp);
1085                 return npages_dirty;
1086         }
1087
1088         i = head = *rmapp & KVMPPC_RMAP_INDEX;
1089         do {
1090                 unsigned long hptep1;
1091                 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4));
1092                 j = rev[i].forw;
1093
1094                 /*
1095                  * Checking the C (changed) bit here is racy since there
1096                  * is no guarantee about when the hardware writes it back.
1097                  * If the HPTE is not writable then it is stable since the
1098                  * page can't be written to, and we would have done a tlbie
1099                  * (which forces the hardware to complete any writeback)
1100                  * when making the HPTE read-only.
1101                  * If vcpus are running then this call is racy anyway
1102                  * since the page could get dirtied subsequently, so we
1103                  * expect there to be a further call which would pick up
1104                  * any delayed C bit writeback.
1105                  * Otherwise we need to do the tlbie even if C==0 in
1106                  * order to pick up any delayed writeback of C.
1107                  */
1108                 hptep1 = be64_to_cpu(hptep[1]);
1109                 if (!(hptep1 & HPTE_R_C) &&
1110                     (!hpte_is_writable(hptep1) || vcpus_running(kvm)))
1111                         continue;
1112
1113                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
1114                         /* unlock rmap before spinning on the HPTE lock */
1115                         unlock_rmap(rmapp);
1116                         while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK))
1117                                 cpu_relax();
1118                         goto retry;
1119                 }
1120
1121                 /* Now check and modify the HPTE */
1122                 if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID)))
1123                         continue;
1124
1125                 /* need to make it temporarily absent so C is stable */
1126                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
1127                 kvmppc_invalidate_hpte(kvm, hptep, i);
1128                 v = be64_to_cpu(hptep[0]);
1129                 r = be64_to_cpu(hptep[1]);
1130                 if (r & HPTE_R_C) {
1131                         hptep[1] = cpu_to_be64(r & ~HPTE_R_C);
1132                         if (!(rev[i].guest_rpte & HPTE_R_C)) {
1133                                 rev[i].guest_rpte |= HPTE_R_C;
1134                                 note_hpte_modification(kvm, &rev[i]);
1135                         }
1136                         n = hpte_page_size(v, r);
1137                         n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT;
1138                         if (n > npages_dirty)
1139                                 npages_dirty = n;
1140                         eieio();
1141                 }
1142                 v &= ~(HPTE_V_ABSENT | HPTE_V_HVLOCK);
1143                 v |= HPTE_V_VALID;
1144                 hptep[0] = cpu_to_be64(v);
1145         } while ((i = j) != head);
1146
1147         unlock_rmap(rmapp);
1148         return npages_dirty;
1149 }
1150
1151 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa,
1152                               struct kvm_memory_slot *memslot,
1153                               unsigned long *map)
1154 {
1155         unsigned long gfn;
1156
1157         if (!vpa->dirty || !vpa->pinned_addr)
1158                 return;
1159         gfn = vpa->gpa >> PAGE_SHIFT;
1160         if (gfn < memslot->base_gfn ||
1161             gfn >= memslot->base_gfn + memslot->npages)
1162                 return;
1163
1164         vpa->dirty = false;
1165         if (map)
1166                 __set_bit_le(gfn - memslot->base_gfn, map);
1167 }
1168
1169 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot,
1170                              unsigned long *map)
1171 {
1172         unsigned long i, j;
1173         unsigned long *rmapp;
1174         struct kvm_vcpu *vcpu;
1175
1176         preempt_disable();
1177         rmapp = memslot->arch.rmap;
1178         for (i = 0; i < memslot->npages; ++i) {
1179                 int npages = kvm_test_clear_dirty_npages(kvm, rmapp);
1180                 /*
1181                  * Note that if npages > 0 then i must be a multiple of npages,
1182                  * since we always put huge-page HPTEs in the rmap chain
1183                  * corresponding to their page base address.
1184                  */
1185                 if (npages && map)
1186                         for (j = i; npages; ++j, --npages)
1187                                 __set_bit_le(j, map);
1188                 ++rmapp;
1189         }
1190
1191         /* Harvest dirty bits from VPA and DTL updates */
1192         /* Note: we never modify the SLB shadow buffer areas */
1193         kvm_for_each_vcpu(i, vcpu, kvm) {
1194                 spin_lock(&vcpu->arch.vpa_update_lock);
1195                 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map);
1196                 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map);
1197                 spin_unlock(&vcpu->arch.vpa_update_lock);
1198         }
1199         preempt_enable();
1200         return 0;
1201 }
1202
1203 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
1204                             unsigned long *nb_ret)
1205 {
1206         struct kvm_memory_slot *memslot;
1207         unsigned long gfn = gpa >> PAGE_SHIFT;
1208         struct page *page, *pages[1];
1209         int npages;
1210         unsigned long hva, offset;
1211         unsigned long pa;
1212         unsigned long *physp;
1213         int srcu_idx;
1214
1215         srcu_idx = srcu_read_lock(&kvm->srcu);
1216         memslot = gfn_to_memslot(kvm, gfn);
1217         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
1218                 goto err;
1219         if (!kvm->arch.using_mmu_notifiers) {
1220                 physp = memslot->arch.slot_phys;
1221                 if (!physp)
1222                         goto err;
1223                 physp += gfn - memslot->base_gfn;
1224                 pa = *physp;
1225                 if (!pa) {
1226                         if (kvmppc_get_guest_page(kvm, gfn, memslot,
1227                                                   PAGE_SIZE) < 0)
1228                                 goto err;
1229                         pa = *physp;
1230                 }
1231                 page = pfn_to_page(pa >> PAGE_SHIFT);
1232                 get_page(page);
1233         } else {
1234                 hva = gfn_to_hva_memslot(memslot, gfn);
1235                 npages = get_user_pages_fast(hva, 1, 1, pages);
1236                 if (npages < 1)
1237                         goto err;
1238                 page = pages[0];
1239         }
1240         srcu_read_unlock(&kvm->srcu, srcu_idx);
1241
1242         offset = gpa & (PAGE_SIZE - 1);
1243         if (nb_ret)
1244                 *nb_ret = PAGE_SIZE - offset;
1245         return page_address(page) + offset;
1246
1247  err:
1248         srcu_read_unlock(&kvm->srcu, srcu_idx);
1249         return NULL;
1250 }
1251
1252 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
1253                              bool dirty)
1254 {
1255         struct page *page = virt_to_page(va);
1256         struct kvm_memory_slot *memslot;
1257         unsigned long gfn;
1258         unsigned long *rmap;
1259         int srcu_idx;
1260
1261         put_page(page);
1262
1263         if (!dirty || !kvm->arch.using_mmu_notifiers)
1264                 return;
1265
1266         /* We need to mark this page dirty in the rmap chain */
1267         gfn = gpa >> PAGE_SHIFT;
1268         srcu_idx = srcu_read_lock(&kvm->srcu);
1269         memslot = gfn_to_memslot(kvm, gfn);
1270         if (memslot) {
1271                 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
1272                 lock_rmap(rmap);
1273                 *rmap |= KVMPPC_RMAP_CHANGED;
1274                 unlock_rmap(rmap);
1275         }
1276         srcu_read_unlock(&kvm->srcu, srcu_idx);
1277 }
1278
1279 /*
1280  * Functions for reading and writing the hash table via reads and
1281  * writes on a file descriptor.
1282  *
1283  * Reads return the guest view of the hash table, which has to be
1284  * pieced together from the real hash table and the guest_rpte
1285  * values in the revmap array.
1286  *
1287  * On writes, each HPTE written is considered in turn, and if it
1288  * is valid, it is written to the HPT as if an H_ENTER with the
1289  * exact flag set was done.  When the invalid count is non-zero
1290  * in the header written to the stream, the kernel will make
1291  * sure that that many HPTEs are invalid, and invalidate them
1292  * if not.
1293  */
1294
1295 struct kvm_htab_ctx {
1296         unsigned long   index;
1297         unsigned long   flags;
1298         struct kvm      *kvm;
1299         int             first_pass;
1300 };
1301
1302 #define HPTE_SIZE       (2 * sizeof(unsigned long))
1303
1304 /*
1305  * Returns 1 if this HPT entry has been modified or has pending
1306  * R/C bit changes.
1307  */
1308 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp)
1309 {
1310         unsigned long rcbits_unset;
1311
1312         if (revp->guest_rpte & HPTE_GR_MODIFIED)
1313                 return 1;
1314
1315         /* Also need to consider changes in reference and changed bits */
1316         rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1317         if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) &&
1318             (be64_to_cpu(hptp[1]) & rcbits_unset))
1319                 return 1;
1320
1321         return 0;
1322 }
1323
1324 static long record_hpte(unsigned long flags, __be64 *hptp,
1325                         unsigned long *hpte, struct revmap_entry *revp,
1326                         int want_valid, int first_pass)
1327 {
1328         unsigned long v, r;
1329         unsigned long rcbits_unset;
1330         int ok = 1;
1331         int valid, dirty;
1332
1333         /* Unmodified entries are uninteresting except on the first pass */
1334         dirty = hpte_dirty(revp, hptp);
1335         if (!first_pass && !dirty)
1336                 return 0;
1337
1338         valid = 0;
1339         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1340                 valid = 1;
1341                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1342                     !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED))
1343                         valid = 0;
1344         }
1345         if (valid != want_valid)
1346                 return 0;
1347
1348         v = r = 0;
1349         if (valid || dirty) {
1350                 /* lock the HPTE so it's stable and read it */
1351                 preempt_disable();
1352                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1353                         cpu_relax();
1354                 v = be64_to_cpu(hptp[0]);
1355
1356                 /* re-evaluate valid and dirty from synchronized HPTE value */
1357                 valid = !!(v & HPTE_V_VALID);
1358                 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1359
1360                 /* Harvest R and C into guest view if necessary */
1361                 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1362                 if (valid && (rcbits_unset & be64_to_cpu(hptp[1]))) {
1363                         revp->guest_rpte |= (be64_to_cpu(hptp[1]) &
1364                                 (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED;
1365                         dirty = 1;
1366                 }
1367
1368                 if (v & HPTE_V_ABSENT) {
1369                         v &= ~HPTE_V_ABSENT;
1370                         v |= HPTE_V_VALID;
1371                         valid = 1;
1372                 }
1373                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1374                         valid = 0;
1375
1376                 r = revp->guest_rpte;
1377                 /* only clear modified if this is the right sort of entry */
1378                 if (valid == want_valid && dirty) {
1379                         r &= ~HPTE_GR_MODIFIED;
1380                         revp->guest_rpte = r;
1381                 }
1382                 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory");
1383                 hptp[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
1384                 preempt_enable();
1385                 if (!(valid == want_valid && (first_pass || dirty)))
1386                         ok = 0;
1387         }
1388         hpte[0] = cpu_to_be64(v);
1389         hpte[1] = cpu_to_be64(r);
1390         return ok;
1391 }
1392
1393 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1394                              size_t count, loff_t *ppos)
1395 {
1396         struct kvm_htab_ctx *ctx = file->private_data;
1397         struct kvm *kvm = ctx->kvm;
1398         struct kvm_get_htab_header hdr;
1399         __be64 *hptp;
1400         struct revmap_entry *revp;
1401         unsigned long i, nb, nw;
1402         unsigned long __user *lbuf;
1403         struct kvm_get_htab_header __user *hptr;
1404         unsigned long flags;
1405         int first_pass;
1406         unsigned long hpte[2];
1407
1408         if (!access_ok(VERIFY_WRITE, buf, count))
1409                 return -EFAULT;
1410
1411         first_pass = ctx->first_pass;
1412         flags = ctx->flags;
1413
1414         i = ctx->index;
1415         hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1416         revp = kvm->arch.revmap + i;
1417         lbuf = (unsigned long __user *)buf;
1418
1419         nb = 0;
1420         while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1421                 /* Initialize header */
1422                 hptr = (struct kvm_get_htab_header __user *)buf;
1423                 hdr.n_valid = 0;
1424                 hdr.n_invalid = 0;
1425                 nw = nb;
1426                 nb += sizeof(hdr);
1427                 lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1428
1429                 /* Skip uninteresting entries, i.e. clean on not-first pass */
1430                 if (!first_pass) {
1431                         while (i < kvm->arch.hpt_npte &&
1432                                !hpte_dirty(revp, hptp)) {
1433                                 ++i;
1434                                 hptp += 2;
1435                                 ++revp;
1436                         }
1437                 }
1438                 hdr.index = i;
1439
1440                 /* Grab a series of valid entries */
1441                 while (i < kvm->arch.hpt_npte &&
1442                        hdr.n_valid < 0xffff &&
1443                        nb + HPTE_SIZE < count &&
1444                        record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1445                         /* valid entry, write it out */
1446                         ++hdr.n_valid;
1447                         if (__put_user(hpte[0], lbuf) ||
1448                             __put_user(hpte[1], lbuf + 1))
1449                                 return -EFAULT;
1450                         nb += HPTE_SIZE;
1451                         lbuf += 2;
1452                         ++i;
1453                         hptp += 2;
1454                         ++revp;
1455                 }
1456                 /* Now skip invalid entries while we can */
1457                 while (i < kvm->arch.hpt_npte &&
1458                        hdr.n_invalid < 0xffff &&
1459                        record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1460                         /* found an invalid entry */
1461                         ++hdr.n_invalid;
1462                         ++i;
1463                         hptp += 2;
1464                         ++revp;
1465                 }
1466
1467                 if (hdr.n_valid || hdr.n_invalid) {
1468                         /* write back the header */
1469                         if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1470                                 return -EFAULT;
1471                         nw = nb;
1472                         buf = (char __user *)lbuf;
1473                 } else {
1474                         nb = nw;
1475                 }
1476
1477                 /* Check if we've wrapped around the hash table */
1478                 if (i >= kvm->arch.hpt_npte) {
1479                         i = 0;
1480                         ctx->first_pass = 0;
1481                         break;
1482                 }
1483         }
1484
1485         ctx->index = i;
1486
1487         return nb;
1488 }
1489
1490 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1491                               size_t count, loff_t *ppos)
1492 {
1493         struct kvm_htab_ctx *ctx = file->private_data;
1494         struct kvm *kvm = ctx->kvm;
1495         struct kvm_get_htab_header hdr;
1496         unsigned long i, j;
1497         unsigned long v, r;
1498         unsigned long __user *lbuf;
1499         __be64 *hptp;
1500         unsigned long tmp[2];
1501         ssize_t nb;
1502         long int err, ret;
1503         int rma_setup;
1504
1505         if (!access_ok(VERIFY_READ, buf, count))
1506                 return -EFAULT;
1507
1508         /* lock out vcpus from running while we're doing this */
1509         mutex_lock(&kvm->lock);
1510         rma_setup = kvm->arch.rma_setup_done;
1511         if (rma_setup) {
1512                 kvm->arch.rma_setup_done = 0;   /* temporarily */
1513                 /* order rma_setup_done vs. vcpus_running */
1514                 smp_mb();
1515                 if (atomic_read(&kvm->arch.vcpus_running)) {
1516                         kvm->arch.rma_setup_done = 1;
1517                         mutex_unlock(&kvm->lock);
1518                         return -EBUSY;
1519                 }
1520         }
1521
1522         err = 0;
1523         for (nb = 0; nb + sizeof(hdr) <= count; ) {
1524                 err = -EFAULT;
1525                 if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1526                         break;
1527
1528                 err = 0;
1529                 if (nb + hdr.n_valid * HPTE_SIZE > count)
1530                         break;
1531
1532                 nb += sizeof(hdr);
1533                 buf += sizeof(hdr);
1534
1535                 err = -EINVAL;
1536                 i = hdr.index;
1537                 if (i >= kvm->arch.hpt_npte ||
1538                     i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte)
1539                         break;
1540
1541                 hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1542                 lbuf = (unsigned long __user *)buf;
1543                 for (j = 0; j < hdr.n_valid; ++j) {
1544                         err = -EFAULT;
1545                         if (__get_user(v, lbuf) || __get_user(r, lbuf + 1))
1546                                 goto out;
1547                         err = -EINVAL;
1548                         if (!(v & HPTE_V_VALID))
1549                                 goto out;
1550                         lbuf += 2;
1551                         nb += HPTE_SIZE;
1552
1553                         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1554                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1555                         err = -EIO;
1556                         ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1557                                                          tmp);
1558                         if (ret != H_SUCCESS) {
1559                                 pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
1560                                        "r=%lx\n", ret, i, v, r);
1561                                 goto out;
1562                         }
1563                         if (!rma_setup && is_vrma_hpte(v)) {
1564                                 unsigned long psize = hpte_page_size(v, r);
1565                                 unsigned long senc = slb_pgsize_encoding(psize);
1566                                 unsigned long lpcr;
1567
1568                                 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1569                                         (VRMA_VSID << SLB_VSID_SHIFT_1T);
1570                                 lpcr = senc << (LPCR_VRMASD_SH - 4);
1571                                 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD);
1572                                 rma_setup = 1;
1573                         }
1574                         ++i;
1575                         hptp += 2;
1576                 }
1577
1578                 for (j = 0; j < hdr.n_invalid; ++j) {
1579                         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1580                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1581                         ++i;
1582                         hptp += 2;
1583                 }
1584                 err = 0;
1585         }
1586
1587  out:
1588         /* Order HPTE updates vs. rma_setup_done */
1589         smp_wmb();
1590         kvm->arch.rma_setup_done = rma_setup;
1591         mutex_unlock(&kvm->lock);
1592
1593         if (err)
1594                 return err;
1595         return nb;
1596 }
1597
1598 static int kvm_htab_release(struct inode *inode, struct file *filp)
1599 {
1600         struct kvm_htab_ctx *ctx = filp->private_data;
1601
1602         filp->private_data = NULL;
1603         if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1604                 atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1605         kvm_put_kvm(ctx->kvm);
1606         kfree(ctx);
1607         return 0;
1608 }
1609
1610 static const struct file_operations kvm_htab_fops = {
1611         .read           = kvm_htab_read,
1612         .write          = kvm_htab_write,
1613         .llseek         = default_llseek,
1614         .release        = kvm_htab_release,
1615 };
1616
1617 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1618 {
1619         int ret;
1620         struct kvm_htab_ctx *ctx;
1621         int rwflag;
1622
1623         /* reject flags we don't recognize */
1624         if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1625                 return -EINVAL;
1626         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1627         if (!ctx)
1628                 return -ENOMEM;
1629         kvm_get_kvm(kvm);
1630         ctx->kvm = kvm;
1631         ctx->index = ghf->start_index;
1632         ctx->flags = ghf->flags;
1633         ctx->first_pass = 1;
1634
1635         rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1636         ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
1637         if (ret < 0) {
1638                 kvm_put_kvm(kvm);
1639                 return ret;
1640         }
1641
1642         if (rwflag == O_RDONLY) {
1643                 mutex_lock(&kvm->slots_lock);
1644                 atomic_inc(&kvm->arch.hpte_mod_interest);
1645                 /* make sure kvmppc_do_h_enter etc. see the increment */
1646                 synchronize_srcu_expedited(&kvm->srcu);
1647                 mutex_unlock(&kvm->slots_lock);
1648         }
1649
1650         return ret;
1651 }
1652
1653 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
1654 {
1655         struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
1656
1657         if (cpu_has_feature(CPU_FTR_ARCH_206))
1658                 vcpu->arch.slb_nr = 32;         /* POWER7 */
1659         else
1660                 vcpu->arch.slb_nr = 64;
1661
1662         mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
1663         mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
1664
1665         vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
1666 }