arch/powerpc/kvm/book3s_64_mmu_hv.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License, version 2, as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program; if not, write to the Free Software
  13  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  14  *
  15  * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
  16  */
  17
  18 #include <linux/types.h>
  19 #include <linux/string.h>
  20 #include <linux/kvm.h>
  21 #include <linux/kvm_host.h>
  22 #include <linux/highmem.h>
  23 #include <linux/gfp.h>
  24 #include <linux/slab.h>
  25 #include <linux/hugetlb.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/srcu.h>
  28 #include <linux/anon_inodes.h>
  29 #include <linux/file.h>
  30 #include <linux/debugfs.h>
  31
  32 #include <asm/tlbflush.h>
  33 #include <asm/kvm_ppc.h>
  34 #include <asm/kvm_book3s.h>
  35 #include <asm/book3s/64/mmu-hash.h>
  36 #include <asm/hvcall.h>
  37 #include <asm/synch.h>
  38 #include <asm/ppc-opcode.h>
  39 #include <asm/cputable.h>
  40
  41 #include "trace_hv.h"
  42
  43 /* Power architecture requires HPT is at least 256kB */
  44 #define PPC_MIN_HPT_ORDER       18
  45
  46 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
  47                                 long pte_index, unsigned long pteh,
  48                                 unsigned long ptel, unsigned long *pte_idx_ret);
  49 static void kvmppc_rmap_reset(struct kvm *kvm);
  50
  51 long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
  52 {
  53         unsigned long hpt = 0;
  54         struct revmap_entry *rev;
  55         struct page *page = NULL;
  56         long order = KVM_DEFAULT_HPT_ORDER;
  57
  58         if (htab_orderp) {
  59                 order = *htab_orderp;
  60                 if (order < PPC_MIN_HPT_ORDER)
  61                         order = PPC_MIN_HPT_ORDER;
  62         }
  63
  64         kvm->arch.hpt_cma_alloc = 0;
  65         page = kvm_alloc_hpt(1ul << (order - PAGE_SHIFT));
  66         if (page) {
  67                 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
  68                 memset((void *)hpt, 0, (1ul << order));
  69                 kvm->arch.hpt_cma_alloc = 1;
  70         }
  71
  72         /* Lastly try successively smaller sizes from the page allocator */
  73         /* Only do this if userspace didn't specify a size via ioctl */
  74         while (!hpt && order > PPC_MIN_HPT_ORDER && !htab_orderp) {
  75                 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
  76                                        __GFP_NOWARN, order - PAGE_SHIFT);
  77                 if (!hpt)
  78                         --order;
  79         }
  80
  81         if (!hpt)
  82                 return -ENOMEM;
  83
  84         kvm->arch.hpt_virt = hpt;
  85         kvm->arch.hpt_order = order;
  86         /* HPTEs are 2**4 bytes long */
  87         kvm->arch.hpt_npte = 1ul << (order - 4);
  88         /* 128 (2**7) bytes in each HPTEG */
  89         kvm->arch.hpt_mask = (1ul << (order - 7)) - 1;
  90
  91         /* Allocate reverse map array */
  92         rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte);
  93         if (!rev) {
  94                 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
  95                 goto out_freehpt;
  96         }
  97         kvm->arch.revmap = rev;
  98         kvm->arch.sdr1 = __pa(hpt) | (order - 18);
  99
 100         pr_info("KVM guest htab at %lx (order %ld), LPID %x\n",
 101                 hpt, order, kvm->arch.lpid);
 102
 103         if (htab_orderp)
 104                 *htab_orderp = order;
 105         return 0;
 106
 107  out_freehpt:
 108         if (kvm->arch.hpt_cma_alloc)
 109                 kvm_release_hpt(page, 1 << (order - PAGE_SHIFT));
 110         else
 111                 free_pages(hpt, order - PAGE_SHIFT);
 112         return -ENOMEM;
 113 }
 114
 115 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
 116 {
 117         long err = -EBUSY;
 118         long order;
 119
 120         mutex_lock(&kvm->lock);
 121         if (kvm->arch.hpte_setup_done) {
 122                 kvm->arch.hpte_setup_done = 0;
 123                 /* order hpte_setup_done vs. vcpus_running */
 124                 smp_mb();
 125                 if (atomic_read(&kvm->arch.vcpus_running)) {
 126                         kvm->arch.hpte_setup_done = 1;
 127                         goto out;
 128                 }
 129         }
 130         if (kvm->arch.hpt_virt) {
 131                 order = kvm->arch.hpt_order;
 132                 /* Set the entire HPT to 0, i.e. invalid HPTEs */
 133                 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order);
 134                 /*
 135                  * Reset all the reverse-mapping chains for all memslots
 136                  */
 137                 kvmppc_rmap_reset(kvm);
 138                 /* Ensure that each vcpu will flush its TLB on next entry. */
 139                 cpumask_setall(&kvm->arch.need_tlb_flush);
 140                 *htab_orderp = order;
 141                 err = 0;
 142         } else {
 143                 err = kvmppc_alloc_hpt(kvm, htab_orderp);
 144                 order = *htab_orderp;
 145         }
 146  out:
 147         mutex_unlock(&kvm->lock);
 148         return err;
 149 }
 150
 151 void kvmppc_free_hpt(struct kvm *kvm)
 152 {
 153         kvmppc_free_lpid(kvm->arch.lpid);
 154         vfree(kvm->arch.revmap);
 155         if (kvm->arch.hpt_cma_alloc)
 156                 kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt),
 157                                 1 << (kvm->arch.hpt_order - PAGE_SHIFT));
 158         else
 159                 free_pages(kvm->arch.hpt_virt,
 160                            kvm->arch.hpt_order - PAGE_SHIFT);
 161 }
 162
 163 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
 164 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
 165 {
 166         return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
 167 }
 168
 169 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
 170 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
 171 {
 172         return (pgsize == 0x10000) ? 0x1000 : 0;
 173 }
 174
 175 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
 176                      unsigned long porder)
 177 {
 178         unsigned long i;
 179         unsigned long npages;
 180         unsigned long hp_v, hp_r;
 181         unsigned long addr, hash;
 182         unsigned long psize;
 183         unsigned long hp0, hp1;
 184         unsigned long idx_ret;
 185         long ret;
 186         struct kvm *kvm = vcpu->kvm;
 187
 188         psize = 1ul << porder;
 189         npages = memslot->npages >> (porder - PAGE_SHIFT);
 190
 191         /* VRMA can't be > 1TB */
 192         if (npages > 1ul << (40 - porder))
 193                 npages = 1ul << (40 - porder);
 194         /* Can't use more than 1 HPTE per HPTEG */
 195         if (npages > kvm->arch.hpt_mask + 1)
 196                 npages = kvm->arch.hpt_mask + 1;
 197
 198         hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
 199                 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
 200         hp1 = hpte1_pgsize_encoding(psize) |
 201                 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
 202
 203         for (i = 0; i < npages; ++i) {
 204                 addr = i << porder;
 205                 /* can't use hpt_hash since va > 64 bits */
 206                 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask;
 207                 /*
 208                  * We assume that the hash table is empty and no
 209                  * vcpus are using it at this stage.  Since we create
 210                  * at most one HPTE per HPTEG, we just assume entry 7
 211                  * is available and use it.
 212                  */
 213                 hash = (hash << 3) + 7;
 214                 hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
 215                 hp_r = hp1 | addr;
 216                 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
 217                                                  &idx_ret);
 218                 if (ret != H_SUCCESS) {
 219                         pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
 220                                addr, ret);
 221                         break;
 222                 }
 223         }
 224 }
 225
 226 int kvmppc_mmu_hv_init(void)
 227 {
 228         unsigned long host_lpid, rsvd_lpid;
 229
 230         if (!cpu_has_feature(CPU_FTR_HVMODE))
 231                 return -EINVAL;
 232
 233         /* POWER7 has 10-bit LPIDs (12-bit in POWER8) */
 234         host_lpid = mfspr(SPRN_LPID);
 235         rsvd_lpid = LPID_RSVD;
 236
 237         kvmppc_init_lpid(rsvd_lpid + 1);
 238
 239         kvmppc_claim_lpid(host_lpid);
 240         /* rsvd_lpid is reserved for use in partition switching */
 241         kvmppc_claim_lpid(rsvd_lpid);
 242
 243         return 0;
 244 }
 245
 246 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
 247 {
 248         unsigned long msr = vcpu->arch.intr_msr;
 249
 250         /* If transactional, change to suspend mode on IRQ delivery */
 251         if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
 252                 msr |= MSR_TS_S;
 253         else
 254                 msr |= vcpu->arch.shregs.msr & MSR_TS_MASK;
 255         kvmppc_set_msr(vcpu, msr);
 256 }
 257
 258 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
 259                                 long pte_index, unsigned long pteh,
 260                                 unsigned long ptel, unsigned long *pte_idx_ret)
 261 {
 262         long ret;
 263
 264         /* Protect linux PTE lookup from page table destruction */
 265         rcu_read_lock_sched();  /* this disables preemption too */
 266         ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
 267                                 current->mm->pgd, false, pte_idx_ret);
 268         rcu_read_unlock_sched();
 269         if (ret == H_TOO_HARD) {
 270                 /* this can't happen */
 271                 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
 272                 ret = H_RESOURCE;       /* or something */
 273         }
 274         return ret;
 275
 276 }
 277
 278 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
 279                                                          gva_t eaddr)
 280 {
 281         u64 mask;
 282         int i;
 283
 284         for (i = 0; i < vcpu->arch.slb_nr; i++) {
 285                 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
 286                         continue;
 287
 288                 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
 289                         mask = ESID_MASK_1T;
 290                 else
 291                         mask = ESID_MASK;
 292
 293                 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
 294                         return &vcpu->arch.slb[i];
 295         }
 296         return NULL;
 297 }
 298
 299 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
 300                         unsigned long ea)
 301 {
 302         unsigned long ra_mask;
 303
 304         ra_mask = hpte_page_size(v, r) - 1;
 305         return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
 306 }
 307
 308 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 309                         struct kvmppc_pte *gpte, bool data, bool iswrite)
 310 {
 311         struct kvm *kvm = vcpu->kvm;
 312         struct kvmppc_slb *slbe;
 313         unsigned long slb_v;
 314         unsigned long pp, key;
 315         unsigned long v, gr;
 316         __be64 *hptep;
 317         int index;
 318         int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
 319
 320         /* Get SLB entry */
 321         if (virtmode) {
 322                 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
 323                 if (!slbe)
 324                         return -EINVAL;
 325                 slb_v = slbe->origv;
 326         } else {
 327                 /* real mode access */
 328                 slb_v = vcpu->kvm->arch.vrma_slb_v;
 329         }
 330
 331         preempt_disable();
 332         /* Find the HPTE in the hash table */
 333         index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
 334                                          HPTE_V_VALID | HPTE_V_ABSENT);
 335         if (index < 0) {
 336                 preempt_enable();
 337                 return -ENOENT;
 338         }
 339         hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4));
 340         v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
 341         gr = kvm->arch.revmap[index].guest_rpte;
 342
 343         unlock_hpte(hptep, v);
 344         preempt_enable();
 345
 346         gpte->eaddr = eaddr;
 347         gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
 348
 349         /* Get PP bits and key for permission check */
 350         pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
 351         key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
 352         key &= slb_v;
 353
 354         /* Calculate permissions */
 355         gpte->may_read = hpte_read_permission(pp, key);
 356         gpte->may_write = hpte_write_permission(pp, key);
 357         gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
 358
 359         /* Storage key permission check for POWER7 */
 360         if (data && virtmode) {
 361                 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
 362                 if (amrfield & 1)
 363                         gpte->may_read = 0;
 364                 if (amrfield & 2)
 365                         gpte->may_write = 0;
 366         }
 367
 368         /* Get the guest physical address */
 369         gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
 370         return 0;
 371 }
 372
 373 /*
 374  * Quick test for whether an instruction is a load or a store.
 375  * If the instruction is a load or a store, then this will indicate
 376  * which it is, at least on server processors.  (Embedded processors
 377  * have some external PID instructions that don't follow the rule
 378  * embodied here.)  If the instruction isn't a load or store, then
 379  * this doesn't return anything useful.
 380  */
 381 static int instruction_is_store(unsigned int instr)
 382 {
 383         unsigned int mask;
 384
 385         mask = 0x10000000;
 386         if ((instr & 0xfc000000) == 0x7c000000)
 387                 mask = 0x100;           /* major opcode 31 */
 388         return (instr & mask) != 0;
 389 }
 390
 391 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
 392                                   unsigned long gpa, gva_t ea, int is_store)
 393 {
 394         u32 last_inst;
 395
 396         /*
 397          * If we fail, we just return to the guest and try executing it again.
 398          */
 399         if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
 400                 EMULATE_DONE)
 401                 return RESUME_GUEST;
 402
 403         /*
 404          * WARNING: We do not know for sure whether the instruction we just
 405          * read from memory is the same that caused the fault in the first
 406          * place.  If the instruction we read is neither an load or a store,
 407          * then it can't access memory, so we don't need to worry about
 408          * enforcing access permissions.  So, assuming it is a load or
 409          * store, we just check that its direction (load or store) is
 410          * consistent with the original fault, since that's what we
 411          * checked the access permissions against.  If there is a mismatch
 412          * we just return and retry the instruction.
 413          */
 414
 415         if (instruction_is_store(last_inst) != !!is_store)
 416                 return RESUME_GUEST;
 417
 418         /*
 419          * Emulated accesses are emulated by looking at the hash for
 420          * translation once, then performing the access later. The
 421          * translation could be invalidated in the meantime in which
 422          * point performing the subsequent memory access on the old
 423          * physical address could possibly be a security hole for the
 424          * guest (but not the host).
 425          *
 426          * This is less of an issue for MMIO stores since they aren't
 427          * globally visible. It could be an issue for MMIO loads to
 428          * a certain extent but we'll ignore it for now.
 429          */
 430
 431         vcpu->arch.paddr_accessed = gpa;
 432         vcpu->arch.vaddr_accessed = ea;
 433         return kvmppc_emulate_mmio(run, vcpu);
 434 }
 435
 436 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 437                                 unsigned long ea, unsigned long dsisr)
 438 {
 439         struct kvm *kvm = vcpu->kvm;
 440         unsigned long hpte[3], r;
 441         __be64 *hptep;
 442         unsigned long mmu_seq, psize, pte_size;
 443         unsigned long gpa_base, gfn_base;
 444         unsigned long gpa, gfn, hva, pfn;
 445         struct kvm_memory_slot *memslot;
 446         unsigned long *rmap;
 447         struct revmap_entry *rev;
 448         struct page *page, *pages[1];
 449         long index, ret, npages;
 450         bool is_ci;
 451         unsigned int writing, write_ok;
 452         struct vm_area_struct *vma;
 453         unsigned long rcbits;
 454
 455         /*
 456          * Real-mode code has already searched the HPT and found the
 457          * entry we're interested in.  Lock the entry and check that
 458          * it hasn't changed.  If it has, just return and re-execute the
 459          * instruction.
 460          */
 461         if (ea != vcpu->arch.pgfault_addr)
 462                 return RESUME_GUEST;
 463         index = vcpu->arch.pgfault_index;
 464         hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4));
 465         rev = &kvm->arch.revmap[index];
 466         preempt_disable();
 467         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
 468                 cpu_relax();
 469         hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
 470         hpte[1] = be64_to_cpu(hptep[1]);
 471         hpte[2] = r = rev->guest_rpte;
 472         unlock_hpte(hptep, hpte[0]);
 473         preempt_enable();
 474
 475         if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
 476             hpte[1] != vcpu->arch.pgfault_hpte[1])
 477                 return RESUME_GUEST;
 478
 479         /* Translate the logical address and get the page */
 480         psize = hpte_page_size(hpte[0], r);
 481         gpa_base = r & HPTE_R_RPN & ~(psize - 1);
 482         gfn_base = gpa_base >> PAGE_SHIFT;
 483         gpa = gpa_base | (ea & (psize - 1));
 484         gfn = gpa >> PAGE_SHIFT;
 485         memslot = gfn_to_memslot(kvm, gfn);
 486
 487         trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr);
 488
 489         /* No memslot means it's an emulated MMIO region */
 490         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
 491                 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
 492                                               dsisr & DSISR_ISSTORE);
 493
 494         /*
 495          * This should never happen, because of the slot_is_aligned()
 496          * check in kvmppc_do_h_enter().
 497          */
 498         if (gfn_base < memslot->base_gfn)
 499                 return -EFAULT;
 500
 501         /* used to check for invalidations in progress */
 502         mmu_seq = kvm->mmu_notifier_seq;
 503         smp_rmb();
 504
 505         ret = -EFAULT;
 506         is_ci = false;
 507         pfn = 0;
 508         page = NULL;
 509         pte_size = PAGE_SIZE;
 510         writing = (dsisr & DSISR_ISSTORE) != 0;
 511         /* If writing != 0, then the HPTE must allow writing, if we get here */
 512         write_ok = writing;
 513         hva = gfn_to_hva_memslot(memslot, gfn);
 514         npages = get_user_pages_fast(hva, 1, writing, pages);
 515         if (npages < 1) {
 516                 /* Check if it's an I/O mapping */
 517                 down_read(&current->mm->mmap_sem);
 518                 vma = find_vma(current->mm, hva);
 519                 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
 520                     (vma->vm_flags & VM_PFNMAP)) {
 521                         pfn = vma->vm_pgoff +
 522                                 ((hva - vma->vm_start) >> PAGE_SHIFT);
 523                         pte_size = psize;
 524                         is_ci = pte_ci(__pte((pgprot_val(vma->vm_page_prot))));
 525                         write_ok = vma->vm_flags & VM_WRITE;
 526                 }
 527                 up_read(&current->mm->mmap_sem);
 528                 if (!pfn)
 529                         goto out_put;
 530         } else {
 531                 page = pages[0];
 532                 pfn = page_to_pfn(page);
 533                 if (PageHuge(page)) {
 534                         page = compound_head(page);
 535                         pte_size <<= compound_order(page);
 536                 }
 537                 /* if the guest wants write access, see if that is OK */
 538                 if (!writing && hpte_is_writable(r)) {
 539                         pte_t *ptep, pte;
 540                         unsigned long flags;
 541                         /*
 542                          * We need to protect against page table destruction
 543                          * hugepage split and collapse.
 544                          */
 545                         local_irq_save(flags);
 546                         ptep = find_linux_pte_or_hugepte(current->mm->pgd,
 547                                                          hva, NULL, NULL);
 548                         if (ptep) {
 549                                 pte = kvmppc_read_update_linux_pte(ptep, 1);
 550                                 if (pte_write(pte))
 551                                         write_ok = 1;
 552                         }
 553                         local_irq_restore(flags);
 554                 }
 555         }
 556
 557         if (psize > pte_size)
 558                 goto out_put;
 559
 560         /* Check WIMG vs. the actual page we're accessing */
 561         if (!hpte_cache_flags_ok(r, is_ci)) {
 562                 if (is_ci)
 563                         goto out_put;
 564                 /*
 565                  * Allow guest to map emulated device memory as
 566                  * uncacheable, but actually make it cacheable.
 567                  */
 568                 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
 569         }
 570
 571         /*
 572          * Set the HPTE to point to pfn.
 573          * Since the pfn is at PAGE_SIZE granularity, make sure we
 574          * don't mask out lower-order bits if psize < PAGE_SIZE.
 575          */
 576         if (psize < PAGE_SIZE)
 577                 psize = PAGE_SIZE;
 578         r = (r & ~(HPTE_R_PP0 - psize)) | ((pfn << PAGE_SHIFT) & ~(psize - 1));
 579         if (hpte_is_writable(r) && !write_ok)
 580                 r = hpte_make_readonly(r);
 581         ret = RESUME_GUEST;
 582         preempt_disable();
 583         while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
 584                 cpu_relax();
 585         if ((be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK) != hpte[0] ||
 586                 be64_to_cpu(hptep[1]) != hpte[1] ||
 587                 rev->guest_rpte != hpte[2])
 588                 /* HPTE has been changed under us; let the guest retry */
 589                 goto out_unlock;
 590         hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
 591
 592         /* Always put the HPTE in the rmap chain for the page base address */
 593         rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn];
 594         lock_rmap(rmap);
 595
 596         /* Check if we might have been invalidated; let the guest retry if so */
 597         ret = RESUME_GUEST;
 598         if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
 599                 unlock_rmap(rmap);
 600                 goto out_unlock;
 601         }
 602
 603         /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
 604         rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
 605         r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
 606
 607         if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) {
 608                 /* HPTE was previously valid, so we need to invalidate it */
 609                 unlock_rmap(rmap);
 610                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
 611                 kvmppc_invalidate_hpte(kvm, hptep, index);
 612                 /* don't lose previous R and C bits */
 613                 r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
 614         } else {
 615                 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
 616         }
 617
 618         hptep[1] = cpu_to_be64(r);
 619         eieio();
 620         __unlock_hpte(hptep, hpte[0]);
 621         asm volatile("ptesync" : : : "memory");
 622         preempt_enable();
 623         if (page && hpte_is_writable(r))
 624                 SetPageDirty(page);
 625
 626  out_put:
 627         trace_kvm_page_fault_exit(vcpu, hpte, ret);
 628
 629         if (page) {
 630                 /*
 631                  * We drop pages[0] here, not page because page might
 632                  * have been set to the head page of a compound, but
 633                  * we have to drop the reference on the correct tail
 634                  * page to match the get inside gup()
 635                  */
 636                 put_page(pages[0]);
 637         }
 638         return ret;
 639
 640  out_unlock:
 641         __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
 642         preempt_enable();
 643         goto out_put;
 644 }
 645
 646 static void kvmppc_rmap_reset(struct kvm *kvm)
 647 {
 648         struct kvm_memslots *slots;
 649         struct kvm_memory_slot *memslot;
 650         int srcu_idx;
 651
 652         srcu_idx = srcu_read_lock(&kvm->srcu);
 653         slots = kvm_memslots(kvm);
 654         kvm_for_each_memslot(memslot, slots) {
 655                 /*
 656                  * This assumes it is acceptable to lose reference and
 657                  * change bits across a reset.
 658                  */
 659                 memset(memslot->arch.rmap, 0,
 660                        memslot->npages * sizeof(*memslot->arch.rmap));
 661         }
 662         srcu_read_unlock(&kvm->srcu, srcu_idx);
 663 }
 664
 665 static int kvm_handle_hva_range(struct kvm *kvm,
 666                                 unsigned long start,
 667                                 unsigned long end,
 668                                 int (*handler)(struct kvm *kvm,
 669                                                unsigned long *rmapp,
 670                                                unsigned long gfn))
 671 {
 672         int ret;
 673         int retval = 0;
 674         struct kvm_memslots *slots;
 675         struct kvm_memory_slot *memslot;
 676
 677         slots = kvm_memslots(kvm);
 678         kvm_for_each_memslot(memslot, slots) {
 679                 unsigned long hva_start, hva_end;
 680                 gfn_t gfn, gfn_end;
 681
 682                 hva_start = max(start, memslot->userspace_addr);
 683                 hva_end = min(end, memslot->userspace_addr +
 684                                         (memslot->npages << PAGE_SHIFT));
 685                 if (hva_start >= hva_end)
 686                         continue;
 687                 /*
 688                  * {gfn(page) | page intersects with [hva_start, hva_end)} =
 689                  * {gfn, gfn+1, ..., gfn_end-1}.
 690                  */
 691                 gfn = hva_to_gfn_memslot(hva_start, memslot);
 692                 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
 693
 694                 for (; gfn < gfn_end; ++gfn) {
 695                         gfn_t gfn_offset = gfn - memslot->base_gfn;
 696
 697                         ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn);
 698                         retval |= ret;
 699                 }
 700         }
 701
 702         return retval;
 703 }
 704
 705 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
 706                           int (*handler)(struct kvm *kvm, unsigned long *rmapp,
 707                                          unsigned long gfn))
 708 {
 709         return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
 710 }
 711
 712 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
 713                            unsigned long gfn)
 714 {
 715         struct revmap_entry *rev = kvm->arch.revmap;
 716         unsigned long h, i, j;
 717         __be64 *hptep;
 718         unsigned long ptel, psize, rcbits;
 719
 720         for (;;) {
 721                 lock_rmap(rmapp);
 722                 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 723                         unlock_rmap(rmapp);
 724                         break;
 725                 }
 726
 727                 /*
 728                  * To avoid an ABBA deadlock with the HPTE lock bit,
 729                  * we can't spin on the HPTE lock while holding the
 730                  * rmap chain lock.
 731                  */
 732                 i = *rmapp & KVMPPC_RMAP_INDEX;
 733                 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4));
 734                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 735                         /* unlock rmap before spinning on the HPTE lock */
 736                         unlock_rmap(rmapp);
 737                         while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
 738                                 cpu_relax();
 739                         continue;
 740                 }
 741                 j = rev[i].forw;
 742                 if (j == i) {
 743                         /* chain is now empty */
 744                         *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
 745                 } else {
 746                         /* remove i from chain */
 747                         h = rev[i].back;
 748                         rev[h].forw = j;
 749                         rev[j].back = h;
 750                         rev[i].forw = rev[i].back = i;
 751                         *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
 752                 }
 753
 754                 /* Now check and modify the HPTE */
 755                 ptel = rev[i].guest_rpte;
 756                 psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel);
 757                 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
 758                     hpte_rpn(ptel, psize) == gfn) {
 759                         hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
 760                         kvmppc_invalidate_hpte(kvm, hptep, i);
 761                         /* Harvest R and C */
 762                         rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
 763                         *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
 764                         if (rcbits & HPTE_R_C)
 765                                 kvmppc_update_rmap_change(rmapp, psize);
 766                         if (rcbits & ~rev[i].guest_rpte) {
 767                                 rev[i].guest_rpte = ptel | rcbits;
 768                                 note_hpte_modification(kvm, &rev[i]);
 769                         }
 770                 }
 771                 unlock_rmap(rmapp);
 772                 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
 773         }
 774         return 0;
 775 }
 776
 777 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva)
 778 {
 779         kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
 780         return 0;
 781 }
 782
 783 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end)
 784 {
 785         kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp);
 786         return 0;
 787 }
 788
 789 void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
 790                                   struct kvm_memory_slot *memslot)
 791 {
 792         unsigned long *rmapp;
 793         unsigned long gfn;
 794         unsigned long n;
 795
 796         rmapp = memslot->arch.rmap;
 797         gfn = memslot->base_gfn;
 798         for (n = memslot->npages; n; --n) {
 799                 /*
 800                  * Testing the present bit without locking is OK because
 801                  * the memslot has been marked invalid already, and hence
 802                  * no new HPTEs referencing this page can be created,
 803                  * thus the present bit can't go from 0 to 1.
 804                  */
 805                 if (*rmapp & KVMPPC_RMAP_PRESENT)
 806                         kvm_unmap_rmapp(kvm, rmapp, gfn);
 807                 ++rmapp;
 808                 ++gfn;
 809         }
 810 }
 811
 812 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
 813                          unsigned long gfn)
 814 {
 815         struct revmap_entry *rev = kvm->arch.revmap;
 816         unsigned long head, i, j;
 817         __be64 *hptep;
 818         int ret = 0;
 819
 820  retry:
 821         lock_rmap(rmapp);
 822         if (*rmapp & KVMPPC_RMAP_REFERENCED) {
 823                 *rmapp &= ~KVMPPC_RMAP_REFERENCED;
 824                 ret = 1;
 825         }
 826         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 827                 unlock_rmap(rmapp);
 828                 return ret;
 829         }
 830
 831         i = head = *rmapp & KVMPPC_RMAP_INDEX;
 832         do {
 833                 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4));
 834                 j = rev[i].forw;
 835
 836                 /* If this HPTE isn't referenced, ignore it */
 837                 if (!(be64_to_cpu(hptep[1]) & HPTE_R_R))
 838                         continue;
 839
 840                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 841                         /* unlock rmap before spinning on the HPTE lock */
 842                         unlock_rmap(rmapp);
 843                         while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
 844                                 cpu_relax();
 845                         goto retry;
 846                 }
 847
 848                 /* Now check and modify the HPTE */
 849                 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
 850                     (be64_to_cpu(hptep[1]) & HPTE_R_R)) {
 851                         kvmppc_clear_ref_hpte(kvm, hptep, i);
 852                         if (!(rev[i].guest_rpte & HPTE_R_R)) {
 853                                 rev[i].guest_rpte |= HPTE_R_R;
 854                                 note_hpte_modification(kvm, &rev[i]);
 855                         }
 856                         ret = 1;
 857                 }
 858                 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
 859         } while ((i = j) != head);
 860
 861         unlock_rmap(rmapp);
 862         return ret;
 863 }
 864
 865 int kvm_age_hva_hv(struct kvm *kvm, unsigned long start, unsigned long end)
 866 {
 867         return kvm_handle_hva_range(kvm, start, end, kvm_age_rmapp);
 868 }
 869
 870 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
 871                               unsigned long gfn)
 872 {
 873         struct revmap_entry *rev = kvm->arch.revmap;
 874         unsigned long head, i, j;
 875         unsigned long *hp;
 876         int ret = 1;
 877
 878         if (*rmapp & KVMPPC_RMAP_REFERENCED)
 879                 return 1;
 880
 881         lock_rmap(rmapp);
 882         if (*rmapp & KVMPPC_RMAP_REFERENCED)
 883                 goto out;
 884
 885         if (*rmapp & KVMPPC_RMAP_PRESENT) {
 886                 i = head = *rmapp & KVMPPC_RMAP_INDEX;
 887                 do {
 888                         hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4));
 889                         j = rev[i].forw;
 890                         if (be64_to_cpu(hp[1]) & HPTE_R_R)
 891                                 goto out;
 892                 } while ((i = j) != head);
 893         }
 894         ret = 0;
 895
 896  out:
 897         unlock_rmap(rmapp);
 898         return ret;
 899 }
 900
 901 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva)
 902 {
 903         return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp);
 904 }
 905
 906 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte)
 907 {
 908         kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
 909 }
 910
 911 static int vcpus_running(struct kvm *kvm)
 912 {
 913         return atomic_read(&kvm->arch.vcpus_running) != 0;
 914 }
 915
 916 /*
 917  * Returns the number of system pages that are dirty.
 918  * This can be more than 1 if we find a huge-page HPTE.
 919  */
 920 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
 921 {
 922         struct revmap_entry *rev = kvm->arch.revmap;
 923         unsigned long head, i, j;
 924         unsigned long n;
 925         unsigned long v, r;
 926         __be64 *hptep;
 927         int npages_dirty = 0;
 928
 929  retry:
 930         lock_rmap(rmapp);
 931         if (*rmapp & KVMPPC_RMAP_CHANGED) {
 932                 long change_order = (*rmapp & KVMPPC_RMAP_CHG_ORDER)
 933                         >> KVMPPC_RMAP_CHG_SHIFT;
 934                 *rmapp &= ~(KVMPPC_RMAP_CHANGED | KVMPPC_RMAP_CHG_ORDER);
 935                 npages_dirty = 1;
 936                 if (change_order > PAGE_SHIFT)
 937                         npages_dirty = 1ul << (change_order - PAGE_SHIFT);
 938         }
 939         if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
 940                 unlock_rmap(rmapp);
 941                 return npages_dirty;
 942         }
 943
 944         i = head = *rmapp & KVMPPC_RMAP_INDEX;
 945         do {
 946                 unsigned long hptep1;
 947                 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4));
 948                 j = rev[i].forw;
 949
 950                 /*
 951                  * Checking the C (changed) bit here is racy since there
 952                  * is no guarantee about when the hardware writes it back.
 953                  * If the HPTE is not writable then it is stable since the
 954                  * page can't be written to, and we would have done a tlbie
 955                  * (which forces the hardware to complete any writeback)
 956                  * when making the HPTE read-only.
 957                  * If vcpus are running then this call is racy anyway
 958                  * since the page could get dirtied subsequently, so we
 959                  * expect there to be a further call which would pick up
 960                  * any delayed C bit writeback.
 961                  * Otherwise we need to do the tlbie even if C==0 in
 962                  * order to pick up any delayed writeback of C.
 963                  */
 964                 hptep1 = be64_to_cpu(hptep[1]);
 965                 if (!(hptep1 & HPTE_R_C) &&
 966                     (!hpte_is_writable(hptep1) || vcpus_running(kvm)))
 967                         continue;
 968
 969                 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
 970                         /* unlock rmap before spinning on the HPTE lock */
 971                         unlock_rmap(rmapp);
 972                         while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK))
 973                                 cpu_relax();
 974                         goto retry;
 975                 }
 976
 977                 /* Now check and modify the HPTE */
 978                 if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) {
 979                         __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
 980                         continue;
 981                 }
 982
 983                 /* need to make it temporarily absent so C is stable */
 984                 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
 985                 kvmppc_invalidate_hpte(kvm, hptep, i);
 986                 v = be64_to_cpu(hptep[0]);
 987                 r = be64_to_cpu(hptep[1]);
 988                 if (r & HPTE_R_C) {
 989                         hptep[1] = cpu_to_be64(r & ~HPTE_R_C);
 990                         if (!(rev[i].guest_rpte & HPTE_R_C)) {
 991                                 rev[i].guest_rpte |= HPTE_R_C;
 992                                 note_hpte_modification(kvm, &rev[i]);
 993                         }
 994                         n = hpte_page_size(v, r);
 995                         n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT;
 996                         if (n > npages_dirty)
 997                                 npages_dirty = n;
 998                         eieio();
 999                 }
1000                 v &= ~HPTE_V_ABSENT;
1001                 v |= HPTE_V_VALID;
1002                 __unlock_hpte(hptep, v);
1003         } while ((i = j) != head);
1004
1005         unlock_rmap(rmapp);
1006         return npages_dirty;
1007 }
1008
1009 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa,
1010                               struct kvm_memory_slot *memslot,
1011                               unsigned long *map)
1012 {
1013         unsigned long gfn;
1014
1015         if (!vpa->dirty || !vpa->pinned_addr)
1016                 return;
1017         gfn = vpa->gpa >> PAGE_SHIFT;
1018         if (gfn < memslot->base_gfn ||
1019             gfn >= memslot->base_gfn + memslot->npages)
1020                 return;
1021
1022         vpa->dirty = false;
1023         if (map)
1024                 __set_bit_le(gfn - memslot->base_gfn, map);
1025 }
1026
1027 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot,
1028                              unsigned long *map)
1029 {
1030         unsigned long i, j;
1031         unsigned long *rmapp;
1032         struct kvm_vcpu *vcpu;
1033
1034         preempt_disable();
1035         rmapp = memslot->arch.rmap;
1036         for (i = 0; i < memslot->npages; ++i) {
1037                 int npages = kvm_test_clear_dirty_npages(kvm, rmapp);
1038                 /*
1039                  * Note that if npages > 0 then i must be a multiple of npages,
1040                  * since we always put huge-page HPTEs in the rmap chain
1041                  * corresponding to their page base address.
1042                  */
1043                 if (npages && map)
1044                         for (j = i; npages; ++j, --npages)
1045                                 __set_bit_le(j, map);
1046                 ++rmapp;
1047         }
1048
1049         /* Harvest dirty bits from VPA and DTL updates */
1050         /* Note: we never modify the SLB shadow buffer areas */
1051         kvm_for_each_vcpu(i, vcpu, kvm) {
1052                 spin_lock(&vcpu->arch.vpa_update_lock);
1053                 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map);
1054                 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map);
1055                 spin_unlock(&vcpu->arch.vpa_update_lock);
1056         }
1057         preempt_enable();
1058         return 0;
1059 }
1060
1061 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
1062                             unsigned long *nb_ret)
1063 {
1064         struct kvm_memory_slot *memslot;
1065         unsigned long gfn = gpa >> PAGE_SHIFT;
1066         struct page *page, *pages[1];
1067         int npages;
1068         unsigned long hva, offset;
1069         int srcu_idx;
1070
1071         srcu_idx = srcu_read_lock(&kvm->srcu);
1072         memslot = gfn_to_memslot(kvm, gfn);
1073         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
1074                 goto err;
1075         hva = gfn_to_hva_memslot(memslot, gfn);
1076         npages = get_user_pages_fast(hva, 1, 1, pages);
1077         if (npages < 1)
1078                 goto err;
1079         page = pages[0];
1080         srcu_read_unlock(&kvm->srcu, srcu_idx);
1081
1082         offset = gpa & (PAGE_SIZE - 1);
1083         if (nb_ret)
1084                 *nb_ret = PAGE_SIZE - offset;
1085         return page_address(page) + offset;
1086
1087  err:
1088         srcu_read_unlock(&kvm->srcu, srcu_idx);
1089         return NULL;
1090 }
1091
1092 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
1093                              bool dirty)
1094 {
1095         struct page *page = virt_to_page(va);
1096         struct kvm_memory_slot *memslot;
1097         unsigned long gfn;
1098         unsigned long *rmap;
1099         int srcu_idx;
1100
1101         put_page(page);
1102
1103         if (!dirty)
1104                 return;
1105
1106         /* We need to mark this page dirty in the rmap chain */
1107         gfn = gpa >> PAGE_SHIFT;
1108         srcu_idx = srcu_read_lock(&kvm->srcu);
1109         memslot = gfn_to_memslot(kvm, gfn);
1110         if (memslot) {
1111                 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
1112                 lock_rmap(rmap);
1113                 *rmap |= KVMPPC_RMAP_CHANGED;
1114                 unlock_rmap(rmap);
1115         }
1116         srcu_read_unlock(&kvm->srcu, srcu_idx);
1117 }
1118
1119 /*
1120  * Functions for reading and writing the hash table via reads and
1121  * writes on a file descriptor.
1122  *
1123  * Reads return the guest view of the hash table, which has to be
1124  * pieced together from the real hash table and the guest_rpte
1125  * values in the revmap array.
1126  *
1127  * On writes, each HPTE written is considered in turn, and if it
1128  * is valid, it is written to the HPT as if an H_ENTER with the
1129  * exact flag set was done.  When the invalid count is non-zero
1130  * in the header written to the stream, the kernel will make
1131  * sure that that many HPTEs are invalid, and invalidate them
1132  * if not.
1133  */
1134
1135 struct kvm_htab_ctx {
1136         unsigned long   index;
1137         unsigned long   flags;
1138         struct kvm      *kvm;
1139         int             first_pass;
1140 };
1141
1142 #define HPTE_SIZE       (2 * sizeof(unsigned long))
1143
1144 /*
1145  * Returns 1 if this HPT entry has been modified or has pending
1146  * R/C bit changes.
1147  */
1148 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp)
1149 {
1150         unsigned long rcbits_unset;
1151
1152         if (revp->guest_rpte & HPTE_GR_MODIFIED)
1153                 return 1;
1154
1155         /* Also need to consider changes in reference and changed bits */
1156         rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1157         if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) &&
1158             (be64_to_cpu(hptp[1]) & rcbits_unset))
1159                 return 1;
1160
1161         return 0;
1162 }
1163
1164 static long record_hpte(unsigned long flags, __be64 *hptp,
1165                         unsigned long *hpte, struct revmap_entry *revp,
1166                         int want_valid, int first_pass)
1167 {
1168         unsigned long v, r;
1169         unsigned long rcbits_unset;
1170         int ok = 1;
1171         int valid, dirty;
1172
1173         /* Unmodified entries are uninteresting except on the first pass */
1174         dirty = hpte_dirty(revp, hptp);
1175         if (!first_pass && !dirty)
1176                 return 0;
1177
1178         valid = 0;
1179         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1180                 valid = 1;
1181                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1182                     !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED))
1183                         valid = 0;
1184         }
1185         if (valid != want_valid)
1186                 return 0;
1187
1188         v = r = 0;
1189         if (valid || dirty) {
1190                 /* lock the HPTE so it's stable and read it */
1191                 preempt_disable();
1192                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1193                         cpu_relax();
1194                 v = be64_to_cpu(hptp[0]);
1195
1196                 /* re-evaluate valid and dirty from synchronized HPTE value */
1197                 valid = !!(v & HPTE_V_VALID);
1198                 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1199
1200                 /* Harvest R and C into guest view if necessary */
1201                 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1202                 if (valid && (rcbits_unset & be64_to_cpu(hptp[1]))) {
1203                         revp->guest_rpte |= (be64_to_cpu(hptp[1]) &
1204                                 (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED;
1205                         dirty = 1;
1206                 }
1207
1208                 if (v & HPTE_V_ABSENT) {
1209                         v &= ~HPTE_V_ABSENT;
1210                         v |= HPTE_V_VALID;
1211                         valid = 1;
1212                 }
1213                 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1214                         valid = 0;
1215
1216                 r = revp->guest_rpte;
1217                 /* only clear modified if this is the right sort of entry */
1218                 if (valid == want_valid && dirty) {
1219                         r &= ~HPTE_GR_MODIFIED;
1220                         revp->guest_rpte = r;
1221                 }
1222                 unlock_hpte(hptp, be64_to_cpu(hptp[0]));
1223                 preempt_enable();
1224                 if (!(valid == want_valid && (first_pass || dirty)))
1225                         ok = 0;
1226         }
1227         hpte[0] = cpu_to_be64(v);
1228         hpte[1] = cpu_to_be64(r);
1229         return ok;
1230 }
1231
1232 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1233                              size_t count, loff_t *ppos)
1234 {
1235         struct kvm_htab_ctx *ctx = file->private_data;
1236         struct kvm *kvm = ctx->kvm;
1237         struct kvm_get_htab_header hdr;
1238         __be64 *hptp;
1239         struct revmap_entry *revp;
1240         unsigned long i, nb, nw;
1241         unsigned long __user *lbuf;
1242         struct kvm_get_htab_header __user *hptr;
1243         unsigned long flags;
1244         int first_pass;
1245         unsigned long hpte[2];
1246
1247         if (!access_ok(VERIFY_WRITE, buf, count))
1248                 return -EFAULT;
1249
1250         first_pass = ctx->first_pass;
1251         flags = ctx->flags;
1252
1253         i = ctx->index;
1254         hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1255         revp = kvm->arch.revmap + i;
1256         lbuf = (unsigned long __user *)buf;
1257
1258         nb = 0;
1259         while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1260                 /* Initialize header */
1261                 hptr = (struct kvm_get_htab_header __user *)buf;
1262                 hdr.n_valid = 0;
1263                 hdr.n_invalid = 0;
1264                 nw = nb;
1265                 nb += sizeof(hdr);
1266                 lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1267
1268                 /* Skip uninteresting entries, i.e. clean on not-first pass */
1269                 if (!first_pass) {
1270                         while (i < kvm->arch.hpt_npte &&
1271                                !hpte_dirty(revp, hptp)) {
1272                                 ++i;
1273                                 hptp += 2;
1274                                 ++revp;
1275                         }
1276                 }
1277                 hdr.index = i;
1278
1279                 /* Grab a series of valid entries */
1280                 while (i < kvm->arch.hpt_npte &&
1281                        hdr.n_valid < 0xffff &&
1282                        nb + HPTE_SIZE < count &&
1283                        record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1284                         /* valid entry, write it out */
1285                         ++hdr.n_valid;
1286                         if (__put_user(hpte[0], lbuf) ||
1287                             __put_user(hpte[1], lbuf + 1))
1288                                 return -EFAULT;
1289                         nb += HPTE_SIZE;
1290                         lbuf += 2;
1291                         ++i;
1292                         hptp += 2;
1293                         ++revp;
1294                 }
1295                 /* Now skip invalid entries while we can */
1296                 while (i < kvm->arch.hpt_npte &&
1297                        hdr.n_invalid < 0xffff &&
1298                        record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1299                         /* found an invalid entry */
1300                         ++hdr.n_invalid;
1301                         ++i;
1302                         hptp += 2;
1303                         ++revp;
1304                 }
1305
1306                 if (hdr.n_valid || hdr.n_invalid) {
1307                         /* write back the header */
1308                         if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1309                                 return -EFAULT;
1310                         nw = nb;
1311                         buf = (char __user *)lbuf;
1312                 } else {
1313                         nb = nw;
1314                 }
1315
1316                 /* Check if we've wrapped around the hash table */
1317                 if (i >= kvm->arch.hpt_npte) {
1318                         i = 0;
1319                         ctx->first_pass = 0;
1320                         break;
1321                 }
1322         }
1323
1324         ctx->index = i;
1325
1326         return nb;
1327 }
1328
1329 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1330                               size_t count, loff_t *ppos)
1331 {
1332         struct kvm_htab_ctx *ctx = file->private_data;
1333         struct kvm *kvm = ctx->kvm;
1334         struct kvm_get_htab_header hdr;
1335         unsigned long i, j;
1336         unsigned long v, r;
1337         unsigned long __user *lbuf;
1338         __be64 *hptp;
1339         unsigned long tmp[2];
1340         ssize_t nb;
1341         long int err, ret;
1342         int hpte_setup;
1343
1344         if (!access_ok(VERIFY_READ, buf, count))
1345                 return -EFAULT;
1346
1347         /* lock out vcpus from running while we're doing this */
1348         mutex_lock(&kvm->lock);
1349         hpte_setup = kvm->arch.hpte_setup_done;
1350         if (hpte_setup) {
1351                 kvm->arch.hpte_setup_done = 0;  /* temporarily */
1352                 /* order hpte_setup_done vs. vcpus_running */
1353                 smp_mb();
1354                 if (atomic_read(&kvm->arch.vcpus_running)) {
1355                         kvm->arch.hpte_setup_done = 1;
1356                         mutex_unlock(&kvm->lock);
1357                         return -EBUSY;
1358                 }
1359         }
1360
1361         err = 0;
1362         for (nb = 0; nb + sizeof(hdr) <= count; ) {
1363                 err = -EFAULT;
1364                 if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1365                         break;
1366
1367                 err = 0;
1368                 if (nb + hdr.n_valid * HPTE_SIZE > count)
1369                         break;
1370
1371                 nb += sizeof(hdr);
1372                 buf += sizeof(hdr);
1373
1374                 err = -EINVAL;
1375                 i = hdr.index;
1376                 if (i >= kvm->arch.hpt_npte ||
1377                     i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte)
1378                         break;
1379
1380                 hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1381                 lbuf = (unsigned long __user *)buf;
1382                 for (j = 0; j < hdr.n_valid; ++j) {
1383                         __be64 hpte_v;
1384                         __be64 hpte_r;
1385
1386                         err = -EFAULT;
1387                         if (__get_user(hpte_v, lbuf) ||
1388                             __get_user(hpte_r, lbuf + 1))
1389                                 goto out;
1390                         v = be64_to_cpu(hpte_v);
1391                         r = be64_to_cpu(hpte_r);
1392                         err = -EINVAL;
1393                         if (!(v & HPTE_V_VALID))
1394                                 goto out;
1395                         lbuf += 2;
1396                         nb += HPTE_SIZE;
1397
1398                         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1399                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1400                         err = -EIO;
1401                         ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1402                                                          tmp);
1403                         if (ret != H_SUCCESS) {
1404                                 pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
1405                                        "r=%lx\n", ret, i, v, r);
1406                                 goto out;
1407                         }
1408                         if (!hpte_setup && is_vrma_hpte(v)) {
1409                                 unsigned long psize = hpte_base_page_size(v, r);
1410                                 unsigned long senc = slb_pgsize_encoding(psize);
1411                                 unsigned long lpcr;
1412
1413                                 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1414                                         (VRMA_VSID << SLB_VSID_SHIFT_1T);
1415                                 lpcr = senc << (LPCR_VRMASD_SH - 4);
1416                                 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD);
1417                                 hpte_setup = 1;
1418                         }
1419                         ++i;
1420                         hptp += 2;
1421                 }
1422
1423                 for (j = 0; j < hdr.n_invalid; ++j) {
1424                         if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1425                                 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1426                         ++i;
1427                         hptp += 2;
1428                 }
1429                 err = 0;
1430         }
1431
1432  out:
1433         /* Order HPTE updates vs. hpte_setup_done */
1434         smp_wmb();
1435         kvm->arch.hpte_setup_done = hpte_setup;
1436         mutex_unlock(&kvm->lock);
1437
1438         if (err)
1439                 return err;
1440         return nb;
1441 }
1442
1443 static int kvm_htab_release(struct inode *inode, struct file *filp)
1444 {
1445         struct kvm_htab_ctx *ctx = filp->private_data;
1446
1447         filp->private_data = NULL;
1448         if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1449                 atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1450         kvm_put_kvm(ctx->kvm);
1451         kfree(ctx);
1452         return 0;
1453 }
1454
1455 static const struct file_operations kvm_htab_fops = {
1456         .read           = kvm_htab_read,
1457         .write          = kvm_htab_write,
1458         .llseek         = default_llseek,
1459         .release        = kvm_htab_release,
1460 };
1461
1462 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1463 {
1464         int ret;
1465         struct kvm_htab_ctx *ctx;
1466         int rwflag;
1467
1468         /* reject flags we don't recognize */
1469         if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1470                 return -EINVAL;
1471         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1472         if (!ctx)
1473                 return -ENOMEM;
1474         kvm_get_kvm(kvm);
1475         ctx->kvm = kvm;
1476         ctx->index = ghf->start_index;
1477         ctx->flags = ghf->flags;
1478         ctx->first_pass = 1;
1479
1480         rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1481         ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
1482         if (ret < 0) {
1483                 kvm_put_kvm(kvm);
1484                 return ret;
1485         }
1486
1487         if (rwflag == O_RDONLY) {
1488                 mutex_lock(&kvm->slots_lock);
1489                 atomic_inc(&kvm->arch.hpte_mod_interest);
1490                 /* make sure kvmppc_do_h_enter etc. see the increment */
1491                 synchronize_srcu_expedited(&kvm->srcu);
1492                 mutex_unlock(&kvm->slots_lock);
1493         }
1494
1495         return ret;
1496 }
1497
1498 struct debugfs_htab_state {
1499         struct kvm      *kvm;
1500         struct mutex    mutex;
1501         unsigned long   hpt_index;
1502         int             chars_left;
1503         int             buf_index;
1504         char            buf[64];
1505 };
1506
1507 static int debugfs_htab_open(struct inode *inode, struct file *file)
1508 {
1509         struct kvm *kvm = inode->i_private;
1510         struct debugfs_htab_state *p;
1511
1512         p = kzalloc(sizeof(*p), GFP_KERNEL);
1513         if (!p)
1514                 return -ENOMEM;
1515
1516         kvm_get_kvm(kvm);
1517         p->kvm = kvm;
1518         mutex_init(&p->mutex);
1519         file->private_data = p;
1520
1521         return nonseekable_open(inode, file);
1522 }
1523
1524 static int debugfs_htab_release(struct inode *inode, struct file *file)
1525 {
1526         struct debugfs_htab_state *p = file->private_data;
1527
1528         kvm_put_kvm(p->kvm);
1529         kfree(p);
1530         return 0;
1531 }
1532
1533 static ssize_t debugfs_htab_read(struct file *file, char __user *buf,
1534                                  size_t len, loff_t *ppos)
1535 {
1536         struct debugfs_htab_state *p = file->private_data;
1537         ssize_t ret, r;
1538         unsigned long i, n;
1539         unsigned long v, hr, gr;
1540         struct kvm *kvm;
1541         __be64 *hptp;
1542
1543         ret = mutex_lock_interruptible(&p->mutex);
1544         if (ret)
1545                 return ret;
1546
1547         if (p->chars_left) {
1548                 n = p->chars_left;
1549                 if (n > len)
1550                         n = len;
1551                 r = copy_to_user(buf, p->buf + p->buf_index, n);
1552                 n -= r;
1553                 p->chars_left -= n;
1554                 p->buf_index += n;
1555                 buf += n;
1556                 len -= n;
1557                 ret = n;
1558                 if (r) {
1559                         if (!n)
1560                                 ret = -EFAULT;
1561                         goto out;
1562                 }
1563         }
1564
1565         kvm = p->kvm;
1566         i = p->hpt_index;
1567         hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1568         for (; len != 0 && i < kvm->arch.hpt_npte; ++i, hptp += 2) {
1569                 if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)))
1570                         continue;
1571
1572                 /* lock the HPTE so it's stable and read it */
1573                 preempt_disable();
1574                 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1575                         cpu_relax();
1576                 v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK;
1577                 hr = be64_to_cpu(hptp[1]);
1578                 gr = kvm->arch.revmap[i].guest_rpte;
1579                 unlock_hpte(hptp, v);
1580                 preempt_enable();
1581
1582                 if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
1583                         continue;
1584
1585                 n = scnprintf(p->buf, sizeof(p->buf),
1586                               "%6lx %.16lx %.16lx %.16lx\n",
1587                               i, v, hr, gr);
1588                 p->chars_left = n;
1589                 if (n > len)
1590                         n = len;
1591                 r = copy_to_user(buf, p->buf, n);
1592                 n -= r;
1593                 p->chars_left -= n;
1594                 p->buf_index = n;
1595                 buf += n;
1596                 len -= n;
1597                 ret += n;
1598                 if (r) {
1599                         if (!ret)
1600                                 ret = -EFAULT;
1601                         goto out;
1602                 }
1603         }
1604         p->hpt_index = i;
1605
1606  out:
1607         mutex_unlock(&p->mutex);
1608         return ret;
1609 }
1610
1611 ssize_t debugfs_htab_write(struct file *file, const char __user *buf,
1612                            size_t len, loff_t *ppos)
1613 {
1614         return -EACCES;
1615 }
1616
1617 static const struct file_operations debugfs_htab_fops = {
1618         .owner   = THIS_MODULE,
1619         .open    = debugfs_htab_open,
1620         .release = debugfs_htab_release,
1621         .read    = debugfs_htab_read,
1622         .write   = debugfs_htab_write,
1623         .llseek  = generic_file_llseek,
1624 };
1625
1626 void kvmppc_mmu_debugfs_init(struct kvm *kvm)
1627 {
1628         kvm->arch.htab_dentry = debugfs_create_file("htab", 0400,
1629                                                     kvm->arch.debugfs_dir, kvm,
1630                                                     &debugfs_htab_fops);
1631 }
1632
1633 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
1634 {
1635         struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
1636
1637         vcpu->arch.slb_nr = 32;         /* POWER7/POWER8 */
1638
1639         mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
1640         mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
1641
1642         vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
1643 }