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;
  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         /*
  68          * try first to allocate it from the kernel page allocator.
  69          * We keep the CMA reserved for failed allocation.
  70          */
  71         hpt = __get_free_pages(GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT |
  72                                __GFP_NOWARN, order - PAGE_SHIFT);
  73
  74         /* Next try to allocate from the preallocated pool */
  75         if (!hpt) {
  76                 VM_BUG_ON(order < KVM_CMA_CHUNK_ORDER);
  77                 page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT));
  78                 if (page) {
  79                         hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
  80                         kvm->arch.hpt_cma_alloc = 1;
  81                 } else
  82                         --order;
  83         }
  84
  85         /* Lastly try successively smaller sizes from the page allocator */
  86         while (!hpt && order > PPC_MIN_HPT_ORDER) {
  87                 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
  88                                        __GFP_NOWARN, order - PAGE_SHIFT);
  89                 if (!hpt)
  90                         --order;
  91         }
  92
  93         if (!hpt)
  94                 return -ENOMEM;
  95
  96         kvm->arch.hpt_virt = hpt;
  97         kvm->arch.hpt_order = order;
  98         /* HPTEs are 2**4 bytes long */
  99         kvm->arch.hpt_npte = 1ul << (order - 4);
 100         /* 128 (2**7) bytes in each HPTEG */
 101         kvm->arch.hpt_mask = (1ul << (order - 7)) - 1;
 102
 103         /* Allocate reverse map array */
 104         rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte);
 105         if (!rev) {
 106                 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
 107                 goto out_freehpt;
 108         }
 109         kvm->arch.revmap = rev;
 110         kvm->arch.sdr1 = __pa(hpt) | (order - 18);
 111
 112         pr_info("KVM guest htab at %lx (order %ld), LPID %x\n",
 113                 hpt, order, kvm->arch.lpid);
 114
 115         if (htab_orderp)
 116                 *htab_orderp = order;
 117         return 0;
 118
 119  out_freehpt:
 120         if (kvm->arch.hpt_cma_alloc)
 121                 kvm_release_hpt(page, 1 << (order - PAGE_SHIFT));
 122         else
 123                 free_pages(hpt, order - PAGE_SHIFT);
 124         return -ENOMEM;
 125 }
 126
 127 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
 128 {
 129         long err = -EBUSY;
 130         long order;
 131
 132         mutex_lock(&kvm->lock);
 133         if (kvm->arch.rma_setup_done) {
 134                 kvm->arch.rma_setup_done = 0;
 135                 /* order rma_setup_done vs. vcpus_running */
 136                 smp_mb();
 137                 if (atomic_read(&kvm->arch.vcpus_running)) {
 138                         kvm->arch.rma_setup_done = 1;
 139                         goto out;
 140                 }
 141         }
 142         if (kvm->arch.hpt_virt) {
 143                 order = kvm->arch.hpt_order;
 144                 /* Set the entire HPT to 0, i.e. invalid HPTEs */
 145                 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order);
 146                 /*
 147                  * Reset all the reverse-mapping chains for all memslots
 148                  */
 149                 kvmppc_rmap_reset(kvm);
 150                 /* Ensure that each vcpu will flush its TLB on next entry. */
 151                 cpumask_setall(&kvm->arch.need_tlb_flush);
 152                 *htab_orderp = order;
 153                 err = 0;
 154         } else {
 155                 err = kvmppc_alloc_hpt(kvm, htab_orderp);
 156                 order = *htab_orderp;
 157         }
 158  out:
 159         mutex_unlock(&kvm->lock);
 160         return err;
 161 }
 162
 163 void kvmppc_free_hpt(struct kvm *kvm)
 164 {
 165         kvmppc_free_lpid(kvm->arch.lpid);
 166         vfree(kvm->arch.revmap);
 167         if (kvm->arch.hpt_cma_alloc)
 168                 kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt),
 169                                 1 << (kvm->arch.hpt_order - PAGE_SHIFT));
 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 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
 264 {
 265         kvmppc_set_msr(vcpu, MSR_SF | MSR_ME);
 266 }
 267
 268 /*
 269  * This is called to get a reference to a guest page if there isn't
 270  * one already in the memslot->arch.slot_phys[] array.
 271  */
 272 static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn,
 273                                   struct kvm_memory_slot *memslot,
 274                                   unsigned long psize)
 275 {
 276         unsigned long start;
 277         long np, err;
 278         struct page *page, *hpage, *pages[1];
 279         unsigned long s, pgsize;
 280         unsigned long *physp;
 281         unsigned int is_io, got, pgorder;
 282         struct vm_area_struct *vma;
 283         unsigned long pfn, i, npages;
 284
 285         physp = memslot->arch.slot_phys;
 286         if (!physp)
 287                 return -EINVAL;
 288         if (physp[gfn - memslot->base_gfn])
 289                 return 0;
 290
 291         is_io = 0;
 292         got = 0;
 293         page = NULL;
 294         pgsize = psize;
 295         err = -EINVAL;
 296         start = gfn_to_hva_memslot(memslot, gfn);
 297
 298         /* Instantiate and get the page we want access to */
 299         np = get_user_pages_fast(start, 1, 1, pages);
 300         if (np != 1) {
 301                 /* Look up the vma for the page */
 302                 down_read(&current->mm->mmap_sem);
 303                 vma = find_vma(current->mm, start);
 304                 if (!vma || vma->vm_start > start ||
 305                     start + psize > vma->vm_end ||
 306                     !(vma->vm_flags & VM_PFNMAP))
 307                         goto up_err;
 308                 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
 309                 pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
 310                 /* check alignment of pfn vs. requested page size */
 311                 if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1)))
 312                         goto up_err;
 313                 up_read(&current->mm->mmap_sem);
 314
 315         } else {
 316                 page = pages[0];
 317                 got = KVMPPC_GOT_PAGE;
 318
 319                 /* See if this is a large page */
 320                 s = PAGE_SIZE;
 321                 if (PageHuge(page)) {
 322                         hpage = compound_head(page);
 323                         s <<= compound_order(hpage);
 324                         /* Get the whole large page if slot alignment is ok */
 325                         if (s > psize && slot_is_aligned(memslot, s) &&
 326                             !(memslot->userspace_addr & (s - 1))) {
 327                                 start &= ~(s - 1);
 328                                 pgsize = s;
 329                                 get_page(hpage);
 330                                 put_page(page);
 331                                 page = hpage;
 332                         }
 333                 }
 334                 if (s < psize)
 335                         goto out;
 336                 pfn = page_to_pfn(page);
 337         }
 338
 339         npages = pgsize >> PAGE_SHIFT;
 340         pgorder = __ilog2(npages);
 341         physp += (gfn - memslot->base_gfn) & ~(npages - 1);
 342         spin_lock(&kvm->arch.slot_phys_lock);
 343         for (i = 0; i < npages; ++i) {
 344                 if (!physp[i]) {
 345                         physp[i] = ((pfn + i) << PAGE_SHIFT) +
 346                                 got + is_io + pgorder;
 347                         got = 0;
 348                 }
 349         }
 350         spin_unlock(&kvm->arch.slot_phys_lock);
 351         err = 0;
 352
 353  out:
 354         if (got)
 355                 put_page(page);
 356         return err;
 357
 358  up_err:
 359         up_read(&current->mm->mmap_sem);
 360         return err;
 361 }
 362
 363 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
 364                                 long pte_index, unsigned long pteh,
 365                                 unsigned long ptel, unsigned long *pte_idx_ret)
 366 {
 367         unsigned long psize, gpa, gfn;
 368         struct kvm_memory_slot *memslot;
 369         long ret;
 370
 371         if (kvm->arch.using_mmu_notifiers)
 372                 goto do_insert;
 373
 374         psize = hpte_page_size(pteh, ptel);
 375         if (!psize)
 376                 return H_PARAMETER;
 377
 378         pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID);
 379
 380         /* Find the memslot (if any) for this address */
 381         gpa = (ptel & HPTE_R_RPN) & ~(psize - 1);
 382         gfn = gpa >> PAGE_SHIFT;
 383         memslot = gfn_to_memslot(kvm, gfn);
 384         if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) {
 385                 if (!slot_is_aligned(memslot, psize))
 386                         return H_PARAMETER;
 387                 if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0)
 388                         return H_PARAMETER;
 389         }
 390
 391  do_insert:
 392         /* Protect linux PTE lookup from page table destruction */
 393         rcu_read_lock_sched();  /* this disables preemption too */
 394         ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
 395                                 current->mm->pgd, false, pte_idx_ret);
 396         rcu_read_unlock_sched();
 397         if (ret == H_TOO_HARD) {
 398                 /* this can't happen */
 399                 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
 400                 ret = H_RESOURCE;       /* or something */
 401         }
 402         return ret;
 403
 404 }
 405
 406 /*
 407  * We come here on a H_ENTER call from the guest when we are not
 408  * using mmu notifiers and we don't have the requested page pinned
 409  * already.
 410  */
 411 long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
 412                              long pte_index, unsigned long pteh,
 413                              unsigned long ptel)
 414 {
 415         return kvmppc_virtmode_do_h_enter(vcpu->kvm, flags, pte_index,
 416                                           pteh, ptel, &vcpu->arch.gpr[4]);
 417 }
 418
 419 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
 420                                                          gva_t eaddr)
 421 {
 422         u64 mask;
 423         int i;
 424
 425         for (i = 0; i < vcpu->arch.slb_nr; i++) {
 426                 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
 427                         continue;
 428
 429                 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
 430                         mask = ESID_MASK_1T;
 431                 else
 432                         mask = ESID_MASK;
 433
 434                 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
 435                         return &vcpu->arch.slb[i];
 436         }
 437         return NULL;
 438 }
 439
 440 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
 441                         unsigned long ea)
 442 {
 443         unsigned long ra_mask;
 444
 445         ra_mask = hpte_page_size(v, r) - 1;
 446         return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
 447 }
 448
 449 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 450                         struct kvmppc_pte *gpte, bool data, bool iswrite)
 451 {
 452         struct kvm *kvm = vcpu->kvm;
 453         struct kvmppc_slb *slbe;
 454         unsigned long slb_v;
 455         unsigned long pp, key;
 456         unsigned long v, gr;
 457         unsigned long *hptep;
 458         int index;
 459         int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
 460
 461         /* Get SLB entry */
 462         if (virtmode) {
 463                 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
 464                 if (!slbe)
 465                         return -EINVAL;
 466                 slb_v = slbe->origv;
 467         } else {
 468                 /* real mode access */
 469                 slb_v = vcpu->kvm->arch.vrma_slb_v;
 470         }
 471
 472         preempt_disable();
 473         /* Find the HPTE in the hash table */
 474         index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
 475                                          HPTE_V_VALID | HPTE_V_ABSENT);
 476         if (index < 0) {
 477                 preempt_enable();
 478                 return -ENOENT;
 479         }
 480         hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
 481         v = hptep[0] & ~HPTE_V_HVLOCK;
 482         gr = kvm->arch.revmap[index].guest_rpte;
 483
 484         /* Unlock the HPTE */
 485         asm volatile("lwsync" : : : "memory");
 486         hptep[0] = v;
 487         preempt_enable();
 488
 489         gpte->eaddr = eaddr;
 490         gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
 491
 492         /* Get PP bits and key for permission check */
 493         pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
 494         key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
 495         key &= slb_v;
 496
 497         /* Calculate permissions */
 498         gpte->may_read = hpte_read_permission(pp, key);
 499         gpte->may_write = hpte_write_permission(pp, key);
 500         gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
 501
 502         /* Storage key permission check for POWER7 */
 503         if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) {
 504                 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
 505                 if (amrfield & 1)
 506                         gpte->may_read = 0;
 507                 if (amrfield & 2)
 508                         gpte->may_write = 0;
 509         }
 510
 511         /* Get the guest physical address */
 512         gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
 513         return 0;
 514 }
 515
 516 /*
 517  * Quick test for whether an instruction is a load or a store.
 518  * If the instruction is a load or a store, then this will indicate
 519  * which it is, at least on server processors.  (Embedded processors
 520  * have some external PID instructions that don't follow the rule
 521  * embodied here.)  If the instruction isn't a load or store, then
 522  * this doesn't return anything useful.
 523  */
 524 static int instruction_is_store(unsigned int instr)
 525 {
 526         unsigned int mask;
 527
 528         mask = 0x10000000;
 529         if ((instr & 0xfc000000) == 0x7c000000)
 530                 mask = 0x100;           /* major opcode 31 */
 531         return (instr & mask) != 0;
 532 }
 533
 534 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
 535                                   unsigned long gpa, gva_t ea, int is_store)
 536 {
 537         int ret;
 538         u32 last_inst;
 539         unsigned long srr0 = kvmppc_get_pc(vcpu);
 540
 541         /* We try to load the last instruction.  We don't let
 542          * emulate_instruction do it as it doesn't check what
 543          * kvmppc_ld returns.
 544          * If we fail, we just return to the guest and try executing it again.
 545          */
 546         if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) {
 547                 ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
 548                 if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED)
 549                         return RESUME_GUEST;
 550                 vcpu->arch.last_inst = last_inst;
 551         }
 552
 553         /*
 554          * WARNING: We do not know for sure whether the instruction we just
 555          * read from memory is the same that caused the fault in the first
 556          * place.  If the instruction we read is neither an load or a store,
 557          * then it can't access memory, so we don't need to worry about
 558          * enforcing access permissions.  So, assuming it is a load or
 559          * store, we just check that its direction (load or store) is
 560          * consistent with the original fault, since that's what we
 561          * checked the access permissions against.  If there is a mismatch
 562          * we just return and retry the instruction.
 563          */
 564
 565         if (instruction_is_store(vcpu->arch.last_inst) != !!is_store)
 566                 return RESUME_GUEST;
 567
 568         /*
 569          * Emulated accesses are emulated by looking at the hash for
 570          * translation once, then performing the access later. The
 571          * translation could be invalidated in the meantime in which
 572          * point performing the subsequent memory access on the old
 573          * physical address could possibly be a security hole for the
 574          * guest (but not the host).
 575          *
 576          * This is less of an issue for MMIO stores since they aren't
 577          * globally visible. It could be an issue for MMIO loads to
 578          * a certain extent but we'll ignore it for now.
 579          */
 580
 581         vcpu->arch.paddr_accessed = gpa;
 582         vcpu->arch.vaddr_accessed = ea;
 583         return kvmppc_emulate_mmio(run, vcpu);
 584 }
 585
 586 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 587                                 unsigned long ea, unsigned long dsisr)
 588 {
 589         struct kvm *kvm = vcpu->kvm;
 590         unsigned long *hptep, hpte[3], r;
 591         unsigned long mmu_seq, psize, pte_size;
 592         unsigned long gpa, gfn, hva, pfn;
 593         struct kvm_memory_slot *memslot;
 594         unsigned long *rmap;
 595         struct revmap_entry *rev;
 596         struct page *page, *pages[1];
 597         long index, ret, npages;
 598         unsigned long is_io;
 599         unsigned int writing, write_ok;
 600         struct vm_area_struct *vma;
 601         unsigned long rcbits;
 602
 603         /*
 604          * Real-mode code has already searched the HPT and found the
 605          * entry we're interested in.  Lock the entry and check that
 606          * it hasn't changed.  If it has, just return and re-execute the
 607          * instruction.
 608          */
 609         if (ea != vcpu->arch.pgfault_addr)
 610                 return RESUME_GUEST;
 611         index = vcpu->arch.pgfault_index;
 612         hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
 613         rev = &kvm->arch.revmap[index];
 614         preempt_disable();
 615         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
 616                 cpu_relax();
 617         hpte[0] = hptep[0] & ~HPTE_V_HVLOCK;
 618         hpte[1] = hptep[1];
 619         hpte[2] = r = rev->guest_rpte;
 620         asm volatile("lwsync" : : : "memory");
 621         hptep[0] = hpte[0];
 622         preempt_enable();
 623
 624         if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
 625             hpte[1] != vcpu->arch.pgfault_hpte[1])
 626                 return RESUME_GUEST;
 627
 628         /* Translate the logical address and get the page */
 629         psize = hpte_page_size(hpte[0], r);
 630         gpa = (r & HPTE_R_RPN & ~(psize - 1)) | (ea & (psize - 1));
 631         gfn = gpa >> PAGE_SHIFT;
 632         memslot = gfn_to_memslot(kvm, gfn);
 633
 634         /* No memslot means it's an emulated MMIO region */
 635         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
 636                 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
 637                                               dsisr & DSISR_ISSTORE);
 638
 639         if (!kvm->arch.using_mmu_notifiers)
 640                 return -EFAULT;         /* should never get here */
 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 ((hptep[0] & ~HPTE_V_HVLOCK) != hpte[0] || hptep[1] != hpte[1] ||
 729             rev->guest_rpte != hpte[2])
 730                 /* HPTE has been changed under us; let the guest retry */
 731                 goto out_unlock;
 732         hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
 733
 734         rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
 735         lock_rmap(rmap);
 736
 737         /* Check if we might have been invalidated; let the guest retry if so */
 738         ret = RESUME_GUEST;
 739         if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
 740                 unlock_rmap(rmap);
 741                 goto out_unlock;
 742         }
 743
 744         /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
 745         rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
 746         r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
 747
 748         if (hptep[0] & HPTE_V_VALID) {
 749                 /* HPTE was previously valid, so we need to invalidate it */
 750                 unlock_rmap(rmap);
 751                 hptep[0] |= HPTE_V_ABSENT;
 752                 kvmppc_invalidate_hpte(kvm, hptep, index);
 753                 /* don't lose previous R and C bits */
 754                 r |= hptep[1] & (HPTE_R_R | HPTE_R_C);
 755         } else {
 756                 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
 757         }
 758
 759         hptep[1] = r;
 760         eieio();
 761         hptep[0] = hpte[0];
 762         asm volatile("ptesync" : : : "memory");
 763         preempt_enable();
 764         if (page && hpte_is_writable(r))
 765                 SetPageDirty(page);
 766
 767  out_put:
 768         if (page) {
 769                 /*
 770                  * We drop pages[0] here, not page because page might
 771                  * have been set to the head page of a compound, but
 772                  * we have to drop the reference on the correct tail
 773                  * page to match the get inside gup()
 774                  */
 775                 put_page(pages[0]);
 776         }
 777         return ret;
 778
 779  out_unlock:
 780         hptep[0] &= ~HPTE_V_HVLOCK;
 781         preempt_enable();
 782         goto out_put;
 783 }
 784
 785 static void kvmppc_rmap_reset(struct kvm *kvm)
 786 {
 787         struct kvm_memslots *slots;
 788         struct kvm_memory_slot *memslot;
 789         int srcu_idx;
 790
 791         srcu_idx = srcu_read_lock(&kvm->srcu);
 792         slots = kvm->memslots;
 793         kvm_for_each_memslot(memslot, slots) {
 794                 /*
 795                  * This assumes it is acceptable to lose reference and
 796                  * change bits across a reset.
 797                  */
 798                 memset(memslot->arch.rmap, 0,
 799                        memslot->npages * sizeof(*memslot->arch.rmap));
 800         }
 801         srcu_read_unlock(&kvm->srcu, srcu_idx);
 802 }
 803
 804 static int kvm_handle_hva_range(struct kvm *kvm,
 805                                 unsigned long start,
 806                                 unsigned long end,
 807                                 int (*handler)(struct kvm *kvm,
 808                                                unsigned long *rmapp,
 809                                                unsigned long gfn))
 810 {
 811         int ret;
 812         int retval = 0;
 813         struct kvm_memslots *slots;
 814         struct kvm_memory_slot *memslot;
 815
 816         slots = kvm_memslots(kvm);
 817         kvm_for_each_memslot(memslot, slots) {
 818                 unsigned long hva_start, hva_end;
 819                 gfn_t gfn, gfn_end;
 820
 821                 hva_start = max(start, memslot->userspace_addr);
 822                 hva_end = min(end, memslot->userspace_addr +
 823                                         (memslot->npages << PAGE_SHIFT));
 824                 if (hva_start >= hva_end)
 825                         continue;
 826                 /*
 827                  * {gfn(page) | page intersects with [hva_start, hva_end)} =
 828                  * {gfn, gfn+1, ..., gfn_end-1}.
 829                  */
 830                 gfn = hva_to_gfn_memslot(hva_start, memslot);
 831                 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
 832
 833                 for (; gfn < gfn_end; ++gfn) {
 834                         gfn_t gfn_offset = gfn - memslot->base_gfn;
 835
 836                         ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn);
 837                         retval |= ret;
 838                 }
 839         }
 840
 841         return retval;
 842 }
 843
 844 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
 845                           int (*handler)(struct kvm *kvm, unsigned long *rmapp,
 846                                          unsigned long gfn))
 847 {
 848         return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
 849 }
 850
 851 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
 852                            unsigned long gfn)
 853 {
 854         struct revmap_entry *rev = kvm->arch.revmap;
 855         unsigned long h, i, j;
 856         unsigned long *hptep;
 857         unsigned long ptel, psize, rcbits;
 858
 859         for (;;) {
 860                 lock_rmap(rmapp);
 861                 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 862                         unlock_rmap(rmapp);
 863                         break;
 864                 }
 865
 866                 /*
 867                  * To avoid an ABBA deadlock with the HPTE lock bit,
 868                  * we can't spin on the HPTE lock while holding the
 869                  * rmap chain lock.
 870                  */
 871                 i = *rmapp & KVMPPC_RMAP_INDEX;
 872                 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
 873                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 874                         /* unlock rmap before spinning on the HPTE lock */
 875                         unlock_rmap(rmapp);
 876                         while (hptep[0] & HPTE_V_HVLOCK)
 877                                 cpu_relax();
 878                         continue;
 879                 }
 880                 j = rev[i].forw;
 881                 if (j == i) {
 882                         /* chain is now empty */
 883                         *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
 884                 } else {
 885                         /* remove i from chain */
 886                         h = rev[i].back;
 887                         rev[h].forw = j;
 888                         rev[j].back = h;
 889                         rev[i].forw = rev[i].back = i;
 890                         *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
 891                 }
 892
 893                 /* Now check and modify the HPTE */
 894                 ptel = rev[i].guest_rpte;
 895                 psize = hpte_page_size(hptep[0], ptel);
 896                 if ((hptep[0] & HPTE_V_VALID) &&
 897                     hpte_rpn(ptel, psize) == gfn) {
 898                         if (kvm->arch.using_mmu_notifiers)
 899                                 hptep[0] |= HPTE_V_ABSENT;
 900                         kvmppc_invalidate_hpte(kvm, hptep, i);
 901                         /* Harvest R and C */
 902                         rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C);
 903                         *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
 904                         if (rcbits & ~rev[i].guest_rpte) {
 905                                 rev[i].guest_rpte = ptel | rcbits;
 906                                 note_hpte_modification(kvm, &rev[i]);
 907                         }
 908                 }
 909                 unlock_rmap(rmapp);
 910                 hptep[0] &= ~HPTE_V_HVLOCK;
 911         }
 912         return 0;
 913 }
 914
 915 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva)
 916 {
 917         if (kvm->arch.using_mmu_notifiers)
 918                 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
 919         return 0;
 920 }
 921
 922 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end)
 923 {
 924         if (kvm->arch.using_mmu_notifiers)
 925                 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp);
 926         return 0;
 927 }
 928
 929 void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
 930                                   struct kvm_memory_slot *memslot)
 931 {
 932         unsigned long *rmapp;
 933         unsigned long gfn;
 934         unsigned long n;
 935
 936         rmapp = memslot->arch.rmap;
 937         gfn = memslot->base_gfn;
 938         for (n = memslot->npages; n; --n) {
 939                 /*
 940                  * Testing the present bit without locking is OK because
 941                  * the memslot has been marked invalid already, and hence
 942                  * no new HPTEs referencing this page can be created,
 943                  * thus the present bit can't go from 0 to 1.
 944                  */
 945                 if (*rmapp & KVMPPC_RMAP_PRESENT)
 946                         kvm_unmap_rmapp(kvm, rmapp, gfn);
 947                 ++rmapp;
 948                 ++gfn;
 949         }
 950 }
 951
 952 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
 953                          unsigned long gfn)
 954 {
 955         struct revmap_entry *rev = kvm->arch.revmap;
 956         unsigned long head, i, j;
 957         unsigned long *hptep;
 958         int ret = 0;
 959
 960  retry:
 961         lock_rmap(rmapp);
 962         if (*rmapp & KVMPPC_RMAP_REFERENCED) {
 963                 *rmapp &= ~KVMPPC_RMAP_REFERENCED;
 964                 ret = 1;
 965         }
 966         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 967                 unlock_rmap(rmapp);
 968                 return ret;
 969         }
 970
 971         i = head = *rmapp & KVMPPC_RMAP_INDEX;
 972         do {
 973                 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
 974                 j = rev[i].forw;
 975
 976                 /* If this HPTE isn't referenced, ignore it */
 977                 if (!(hptep[1] & HPTE_R_R))
 978                         continue;
 979
 980                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 981                         /* unlock rmap before spinning on the HPTE lock */
 982                         unlock_rmap(rmapp);
 983                         while (hptep[0] & HPTE_V_HVLOCK)
 984                                 cpu_relax();
 985                         goto retry;
 986                 }
 987
 988                 /* Now check and modify the HPTE */
 989                 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) {
 990                         kvmppc_clear_ref_hpte(kvm, hptep, i);
 991                         if (!(rev[i].guest_rpte & HPTE_R_R)) {
 992                                 rev[i].guest_rpte |= HPTE_R_R;
 993                                 note_hpte_modification(kvm, &rev[i]);
 994                         }
 995                         ret = 1;
 996                 }
 997                 hptep[0] &= ~HPTE_V_HVLOCK;
 998         } while ((i = j) != head);
 999
1000         unlock_rmap(rmapp);
1001         return ret;
1002 }
1003
1004 int kvm_age_hva_hv(struct kvm *kvm, unsigned long hva)
1005 {
1006         if (!kvm->arch.using_mmu_notifiers)
1007                 return 0;
1008         return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
1009 }
1010
1011 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
1012                               unsigned long gfn)
1013 {
1014         struct revmap_entry *rev = kvm->arch.revmap;
1015         unsigned long head, i, j;
1016         unsigned long *hp;
1017         int ret = 1;
1018
1019         if (*rmapp & KVMPPC_RMAP_REFERENCED)
1020                 return 1;
1021
1022         lock_rmap(rmapp);
1023         if (*rmapp & KVMPPC_RMAP_REFERENCED)
1024                 goto out;
1025
1026         if (*rmapp & KVMPPC_RMAP_PRESENT) {
1027                 i = head = *rmapp & KVMPPC_RMAP_INDEX;
1028                 do {
1029                         hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4));
1030                         j = rev[i].forw;
1031                         if (hp[1] & HPTE_R_R)
1032                                 goto out;
1033                 } while ((i = j) != head);
1034         }
1035         ret = 0;
1036
1037  out:
1038         unlock_rmap(rmapp);
1039         return ret;
1040 }
1041
1042 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva)
1043 {
1044         if (!kvm->arch.using_mmu_notifiers)
1045                 return 0;
1046         return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp);
1047 }
1048
1049 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte)
1050 {
1051         if (!kvm->arch.using_mmu_notifiers)
1052                 return;
1053         kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
1054 }
1055
1056 static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp)
1057 {
1058         struct revmap_entry *rev = kvm->arch.revmap;
1059         unsigned long head, i, j;
1060         unsigned long *hptep;
1061         int ret = 0;
1062
1063  retry:
1064         lock_rmap(rmapp);
1065         if (*rmapp & KVMPPC_RMAP_CHANGED) {
1066                 *rmapp &= ~KVMPPC_RMAP_CHANGED;
1067                 ret = 1;
1068         }
1069         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
1070                 unlock_rmap(rmapp);
1071                 return ret;
1072         }
1073
1074         i = head = *rmapp & KVMPPC_RMAP_INDEX;
1075         do {
1076                 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
1077                 j = rev[i].forw;
1078
1079                 if (!(hptep[1] & HPTE_R_C))
1080                         continue;
1081
1082                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
1083                         /* unlock rmap before spinning on the HPTE lock */
1084                         unlock_rmap(rmapp);
1085                         while (hptep[0] & HPTE_V_HVLOCK)
1086                                 cpu_relax();
1087                         goto retry;
1088                 }
1089
1090                 /* Now check and modify the HPTE */
1091                 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) {
1092                         /* need to make it temporarily absent to clear C */
1093                         hptep[0] |= HPTE_V_ABSENT;
1094                         kvmppc_invalidate_hpte(kvm, hptep, i);
1095                         hptep[1] &= ~HPTE_R_C;
1096                         eieio();
1097                         hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
1098                         if (!(rev[i].guest_rpte & HPTE_R_C)) {
1099                                 rev[i].guest_rpte |= HPTE_R_C;
1100                                 note_hpte_modification(kvm, &rev[i]);
1101                         }
1102                         ret = 1;
1103                 }
1104                 hptep[0] &= ~HPTE_V_HVLOCK;
1105         } while ((i = j) != head);
1106
1107         unlock_rmap(rmapp);
1108         return ret;
1109 }
1110
1111 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa,
1112                               struct kvm_memory_slot *memslot,
1113                               unsigned long *map)
1114 {
1115         unsigned long gfn;
1116
1117         if (!vpa->dirty || !vpa->pinned_addr)
1118                 return;
1119         gfn = vpa->gpa >> PAGE_SHIFT;
1120         if (gfn < memslot->base_gfn ||
1121             gfn >= memslot->base_gfn + memslot->npages)
1122                 return;
1123
1124         vpa->dirty = false;
1125         if (map)
1126                 __set_bit_le(gfn - memslot->base_gfn, map);
1127 }
1128
1129 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot,
1130                              unsigned long *map)
1131 {
1132         unsigned long i;
1133         unsigned long *rmapp;
1134         struct kvm_vcpu *vcpu;
1135
1136         preempt_disable();
1137         rmapp = memslot->arch.rmap;
1138         for (i = 0; i < memslot->npages; ++i) {
1139                 if (kvm_test_clear_dirty(kvm, rmapp) && map)
1140                         __set_bit_le(i, map);
1141                 ++rmapp;
1142         }
1143
1144         /* Harvest dirty bits from VPA and DTL updates */
1145         /* Note: we never modify the SLB shadow buffer areas */
1146         kvm_for_each_vcpu(i, vcpu, kvm) {
1147                 spin_lock(&vcpu->arch.vpa_update_lock);
1148                 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map);
1149                 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map);
1150                 spin_unlock(&vcpu->arch.vpa_update_lock);
1151         }
1152         preempt_enable();
1153         return 0;
1154 }
1155
1156 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
1157                             unsigned long *nb_ret)
1158 {
1159         struct kvm_memory_slot *memslot;
1160         unsigned long gfn = gpa >> PAGE_SHIFT;
1161         struct page *page, *pages[1];
1162         int npages;
1163         unsigned long hva, offset;
1164         unsigned long pa;
1165         unsigned long *physp;
1166         int srcu_idx;
1167
1168         srcu_idx = srcu_read_lock(&kvm->srcu);
1169         memslot = gfn_to_memslot(kvm, gfn);
1170         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
1171                 goto err;
1172         if (!kvm->arch.using_mmu_notifiers) {
1173                 physp = memslot->arch.slot_phys;
1174                 if (!physp)
1175                         goto err;
1176                 physp += gfn - memslot->base_gfn;
1177                 pa = *physp;
1178                 if (!pa) {
1179                         if (kvmppc_get_guest_page(kvm, gfn, memslot,
1180                                                   PAGE_SIZE) < 0)
1181                                 goto err;
1182                         pa = *physp;
1183                 }
1184                 page = pfn_to_page(pa >> PAGE_SHIFT);
1185                 get_page(page);
1186         } else {
1187                 hva = gfn_to_hva_memslot(memslot, gfn);
1188                 npages = get_user_pages_fast(hva, 1, 1, pages);
1189                 if (npages < 1)
1190                         goto err;
1191                 page = pages[0];
1192         }
1193         srcu_read_unlock(&kvm->srcu, srcu_idx);
1194
1195         offset = gpa & (PAGE_SIZE - 1);
1196         if (nb_ret)
1197                 *nb_ret = PAGE_SIZE - offset;
1198         return page_address(page) + offset;
1199
1200  err:
1201         srcu_read_unlock(&kvm->srcu, srcu_idx);
1202         return NULL;
1203 }
1204
1205 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
1206                              bool dirty)
1207 {
1208         struct page *page = virt_to_page(va);
1209         struct kvm_memory_slot *memslot;
1210         unsigned long gfn;
1211         unsigned long *rmap;
1212         int srcu_idx;
1213
1214         put_page(page);
1215
1216         if (!dirty || !kvm->arch.using_mmu_notifiers)
1217                 return;
1218
1219         /* We need to mark this page dirty in the rmap chain */
1220         gfn = gpa >> PAGE_SHIFT;
1221         srcu_idx = srcu_read_lock(&kvm->srcu);
1222         memslot = gfn_to_memslot(kvm, gfn);
1223         if (memslot) {
1224                 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
1225                 lock_rmap(rmap);
1226                 *rmap |= KVMPPC_RMAP_CHANGED;
1227                 unlock_rmap(rmap);
1228         }
1229         srcu_read_unlock(&kvm->srcu, srcu_idx);
1230 }
1231
1232 /*
1233  * Functions for reading and writing the hash table via reads and
1234  * writes on a file descriptor.
1235  *
1236  * Reads return the guest view of the hash table, which has to be
1237  * pieced together from the real hash table and the guest_rpte
1238  * values in the revmap array.
1239  *
1240  * On writes, each HPTE written is considered in turn, and if it
1241  * is valid, it is written to the HPT as if an H_ENTER with the
1242  * exact flag set was done.  When the invalid count is non-zero
1243  * in the header written to the stream, the kernel will make
1244  * sure that that many HPTEs are invalid, and invalidate them
1245  * if not.
1246  */
1247
1248 struct kvm_htab_ctx {
1249         unsigned long   index;
1250         unsigned long   flags;
1251         struct kvm      *kvm;
1252         int             first_pass;
1253 };
1254
1255 #define HPTE_SIZE       (2 * sizeof(unsigned long))
1256
1257 /*
1258  * Returns 1 if this HPT entry has been modified or has pending
1259  * R/C bit changes.
1260  */
1261 static int hpte_dirty(struct revmap_entry *revp, unsigned long *hptp)
1262 {
1263         unsigned long rcbits_unset;
1264
1265         if (revp->guest_rpte & HPTE_GR_MODIFIED)
1266                 return 1;
1267
1268         /* Also need to consider changes in reference and changed bits */
1269         rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1270         if ((hptp[0] & HPTE_V_VALID) && (hptp[1] & rcbits_unset))
1271                 return 1;
1272
1273         return 0;
1274 }
1275
1276 static long record_hpte(unsigned long flags, unsigned long *hptp,
1277                         unsigned long *hpte, struct revmap_entry *revp,
1278                         int want_valid, int first_pass)
1279 {
1280         unsigned long v, r;
1281         unsigned long rcbits_unset;
1282         int ok = 1;
1283         int valid, dirty;
1284
1285         /* Unmodified entries are uninteresting except on the first pass */
1286         dirty = hpte_dirty(revp, hptp);
1287         if (!first_pass && !dirty)
1288                 return 0;
1289
1290         valid = 0;
1291         if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1292                 valid = 1;
1293                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1294                     !(hptp[0] & HPTE_V_BOLTED))
1295                         valid = 0;
1296         }
1297         if (valid != want_valid)
1298                 return 0;
1299
1300         v = r = 0;
1301         if (valid || dirty) {
1302                 /* lock the HPTE so it's stable and read it */
1303                 preempt_disable();
1304                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1305                         cpu_relax();
1306                 v = hptp[0];
1307
1308                 /* re-evaluate valid and dirty from synchronized HPTE value */
1309                 valid = !!(v & HPTE_V_VALID);
1310                 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1311
1312                 /* Harvest R and C into guest view if necessary */
1313                 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1314                 if (valid && (rcbits_unset & hptp[1])) {
1315                         revp->guest_rpte |= (hptp[1] & (HPTE_R_R | HPTE_R_C)) |
1316                                 HPTE_GR_MODIFIED;
1317                         dirty = 1;
1318                 }
1319
1320                 if (v & HPTE_V_ABSENT) {
1321                         v &= ~HPTE_V_ABSENT;
1322                         v |= HPTE_V_VALID;
1323                         valid = 1;
1324                 }
1325                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1326                         valid = 0;
1327
1328                 r = revp->guest_rpte;
1329                 /* only clear modified if this is the right sort of entry */
1330                 if (valid == want_valid && dirty) {
1331                         r &= ~HPTE_GR_MODIFIED;
1332                         revp->guest_rpte = r;
1333                 }
1334                 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory");
1335                 hptp[0] &= ~HPTE_V_HVLOCK;
1336                 preempt_enable();
1337                 if (!(valid == want_valid && (first_pass || dirty)))
1338                         ok = 0;
1339         }
1340         hpte[0] = v;
1341         hpte[1] = r;
1342         return ok;
1343 }
1344
1345 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1346                              size_t count, loff_t *ppos)
1347 {
1348         struct kvm_htab_ctx *ctx = file->private_data;
1349         struct kvm *kvm = ctx->kvm;
1350         struct kvm_get_htab_header hdr;
1351         unsigned long *hptp;
1352         struct revmap_entry *revp;
1353         unsigned long i, nb, nw;
1354         unsigned long __user *lbuf;
1355         struct kvm_get_htab_header __user *hptr;
1356         unsigned long flags;
1357         int first_pass;
1358         unsigned long hpte[2];
1359
1360         if (!access_ok(VERIFY_WRITE, buf, count))
1361                 return -EFAULT;
1362
1363         first_pass = ctx->first_pass;
1364         flags = ctx->flags;
1365
1366         i = ctx->index;
1367         hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1368         revp = kvm->arch.revmap + i;
1369         lbuf = (unsigned long __user *)buf;
1370
1371         nb = 0;
1372         while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1373                 /* Initialize header */
1374                 hptr = (struct kvm_get_htab_header __user *)buf;
1375                 hdr.n_valid = 0;
1376                 hdr.n_invalid = 0;
1377                 nw = nb;
1378                 nb += sizeof(hdr);
1379                 lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1380
1381                 /* Skip uninteresting entries, i.e. clean on not-first pass */
1382                 if (!first_pass) {
1383                         while (i < kvm->arch.hpt_npte &&
1384                                !hpte_dirty(revp, hptp)) {
1385                                 ++i;
1386                                 hptp += 2;
1387                                 ++revp;
1388                         }
1389                 }
1390                 hdr.index = i;
1391
1392                 /* Grab a series of valid entries */
1393                 while (i < kvm->arch.hpt_npte &&
1394                        hdr.n_valid < 0xffff &&
1395                        nb + HPTE_SIZE < count &&
1396                        record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1397                         /* valid entry, write it out */
1398                         ++hdr.n_valid;
1399                         if (__put_user(hpte[0], lbuf) ||
1400                             __put_user(hpte[1], lbuf + 1))
1401                                 return -EFAULT;
1402                         nb += HPTE_SIZE;
1403                         lbuf += 2;
1404                         ++i;
1405                         hptp += 2;
1406                         ++revp;
1407                 }
1408                 /* Now skip invalid entries while we can */
1409                 while (i < kvm->arch.hpt_npte &&
1410                        hdr.n_invalid < 0xffff &&
1411                        record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1412                         /* found an invalid entry */
1413                         ++hdr.n_invalid;
1414                         ++i;
1415                         hptp += 2;
1416                         ++revp;
1417                 }
1418
1419                 if (hdr.n_valid || hdr.n_invalid) {
1420                         /* write back the header */
1421                         if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1422                                 return -EFAULT;
1423                         nw = nb;
1424                         buf = (char __user *)lbuf;
1425                 } else {
1426                         nb = nw;
1427                 }
1428
1429                 /* Check if we've wrapped around the hash table */
1430                 if (i >= kvm->arch.hpt_npte) {
1431                         i = 0;
1432                         ctx->first_pass = 0;
1433                         break;
1434                 }
1435         }
1436
1437         ctx->index = i;
1438
1439         return nb;
1440 }
1441
1442 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1443                               size_t count, loff_t *ppos)
1444 {
1445         struct kvm_htab_ctx *ctx = file->private_data;
1446         struct kvm *kvm = ctx->kvm;
1447         struct kvm_get_htab_header hdr;
1448         unsigned long i, j;
1449         unsigned long v, r;
1450         unsigned long __user *lbuf;
1451         unsigned long *hptp;
1452         unsigned long tmp[2];
1453         ssize_t nb;
1454         long int err, ret;
1455         int rma_setup;
1456
1457         if (!access_ok(VERIFY_READ, buf, count))
1458                 return -EFAULT;
1459
1460         /* lock out vcpus from running while we're doing this */
1461         mutex_lock(&kvm->lock);
1462         rma_setup = kvm->arch.rma_setup_done;
1463         if (rma_setup) {
1464                 kvm->arch.rma_setup_done = 0;   /* temporarily */
1465                 /* order rma_setup_done vs. vcpus_running */
1466                 smp_mb();
1467                 if (atomic_read(&kvm->arch.vcpus_running)) {
1468                         kvm->arch.rma_setup_done = 1;
1469                         mutex_unlock(&kvm->lock);
1470                         return -EBUSY;
1471                 }
1472         }
1473
1474         err = 0;
1475         for (nb = 0; nb + sizeof(hdr) <= count; ) {
1476                 err = -EFAULT;
1477                 if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1478                         break;
1479
1480                 err = 0;
1481                 if (nb + hdr.n_valid * HPTE_SIZE > count)
1482                         break;
1483
1484                 nb += sizeof(hdr);
1485                 buf += sizeof(hdr);
1486
1487                 err = -EINVAL;
1488                 i = hdr.index;
1489                 if (i >= kvm->arch.hpt_npte ||
1490                     i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte)
1491                         break;
1492
1493                 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1494                 lbuf = (unsigned long __user *)buf;
1495                 for (j = 0; j < hdr.n_valid; ++j) {
1496                         err = -EFAULT;
1497                         if (__get_user(v, lbuf) || __get_user(r, lbuf + 1))
1498                                 goto out;
1499                         err = -EINVAL;
1500                         if (!(v & HPTE_V_VALID))
1501                                 goto out;
1502                         lbuf += 2;
1503                         nb += HPTE_SIZE;
1504
1505                         if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT))
1506                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1507                         err = -EIO;
1508                         ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1509                                                          tmp);
1510                         if (ret != H_SUCCESS) {
1511                                 pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
1512                                        "r=%lx\n", ret, i, v, r);
1513                                 goto out;
1514                         }
1515                         if (!rma_setup && is_vrma_hpte(v)) {
1516                                 unsigned long psize = hpte_page_size(v, r);
1517                                 unsigned long senc = slb_pgsize_encoding(psize);
1518                                 unsigned long lpcr;
1519
1520                                 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1521                                         (VRMA_VSID << SLB_VSID_SHIFT_1T);
1522                                 lpcr = senc << (LPCR_VRMASD_SH - 4);
1523                                 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD);
1524                                 rma_setup = 1;
1525                         }
1526                         ++i;
1527                         hptp += 2;
1528                 }
1529
1530                 for (j = 0; j < hdr.n_invalid; ++j) {
1531                         if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT))
1532                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1533                         ++i;
1534                         hptp += 2;
1535                 }
1536                 err = 0;
1537         }
1538
1539  out:
1540         /* Order HPTE updates vs. rma_setup_done */
1541         smp_wmb();
1542         kvm->arch.rma_setup_done = rma_setup;
1543         mutex_unlock(&kvm->lock);
1544
1545         if (err)
1546                 return err;
1547         return nb;
1548 }
1549
1550 static int kvm_htab_release(struct inode *inode, struct file *filp)
1551 {
1552         struct kvm_htab_ctx *ctx = filp->private_data;
1553
1554         filp->private_data = NULL;
1555         if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1556                 atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1557         kvm_put_kvm(ctx->kvm);
1558         kfree(ctx);
1559         return 0;
1560 }
1561
1562 static const struct file_operations kvm_htab_fops = {
1563         .read           = kvm_htab_read,
1564         .write          = kvm_htab_write,
1565         .llseek         = default_llseek,
1566         .release        = kvm_htab_release,
1567 };
1568
1569 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1570 {
1571         int ret;
1572         struct kvm_htab_ctx *ctx;
1573         int rwflag;
1574
1575         /* reject flags we don't recognize */
1576         if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1577                 return -EINVAL;
1578         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1579         if (!ctx)
1580                 return -ENOMEM;
1581         kvm_get_kvm(kvm);
1582         ctx->kvm = kvm;
1583         ctx->index = ghf->start_index;
1584         ctx->flags = ghf->flags;
1585         ctx->first_pass = 1;
1586
1587         rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1588         ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
1589         if (ret < 0) {
1590                 kvm_put_kvm(kvm);
1591                 return ret;
1592         }
1593
1594         if (rwflag == O_RDONLY) {
1595                 mutex_lock(&kvm->slots_lock);
1596                 atomic_inc(&kvm->arch.hpte_mod_interest);
1597                 /* make sure kvmppc_do_h_enter etc. see the increment */
1598                 synchronize_srcu_expedited(&kvm->srcu);
1599                 mutex_unlock(&kvm->slots_lock);
1600         }
1601
1602         return ret;
1603 }
1604
1605 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
1606 {
1607         struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
1608
1609         if (cpu_has_feature(CPU_FTR_ARCH_206))
1610                 vcpu->arch.slb_nr = 32;         /* POWER7 */
1611         else
1612                 vcpu->arch.slb_nr = 64;
1613
1614         mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
1615         mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
1616
1617         vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
1618 }