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/mmu-hash64.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 while (!hpt && order > PPC_MIN_HPT_ORDER) { 74 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT| 75 __GFP_NOWARN, order - PAGE_SHIFT); 76 if (!hpt) 77 --order; 78 } 79 80 if (!hpt) 81 return -ENOMEM; 82 83 kvm->arch.hpt_virt = hpt; 84 kvm->arch.hpt_order = order; 85 /* HPTEs are 2**4 bytes long */ 86 kvm->arch.hpt_npte = 1ul << (order - 4); 87 /* 128 (2**7) bytes in each HPTEG */ 88 kvm->arch.hpt_mask = (1ul << (order - 7)) - 1; 89 90 /* Allocate reverse map array */ 91 rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte); 92 if (!rev) { 93 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n"); 94 goto out_freehpt; 95 } 96 kvm->arch.revmap = rev; 97 kvm->arch.sdr1 = __pa(hpt) | (order - 18); 98 99 pr_info("KVM guest htab at %lx (order %ld), LPID %x\n", 100 hpt, order, kvm->arch.lpid); 101 102 if (htab_orderp) 103 *htab_orderp = order; 104 return 0; 105 106 out_freehpt: 107 if (kvm->arch.hpt_cma_alloc) 108 kvm_release_hpt(page, 1 << (order - PAGE_SHIFT)); 109 else 110 free_pages(hpt, order - PAGE_SHIFT); 111 return -ENOMEM; 112 } 113 114 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp) 115 { 116 long err = -EBUSY; 117 long order; 118 119 mutex_lock(&kvm->lock); 120 if (kvm->arch.hpte_setup_done) { 121 kvm->arch.hpte_setup_done = 0; 122 /* order hpte_setup_done vs. vcpus_running */ 123 smp_mb(); 124 if (atomic_read(&kvm->arch.vcpus_running)) { 125 kvm->arch.hpte_setup_done = 1; 126 goto out; 127 } 128 } 129 if (kvm->arch.hpt_virt) { 130 order = kvm->arch.hpt_order; 131 /* Set the entire HPT to 0, i.e. invalid HPTEs */ 132 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order); 133 /* 134 * Reset all the reverse-mapping chains for all memslots 135 */ 136 kvmppc_rmap_reset(kvm); 137 /* Ensure that each vcpu will flush its TLB on next entry. */ 138 cpumask_setall(&kvm->arch.need_tlb_flush); 139 *htab_orderp = order; 140 err = 0; 141 } else { 142 err = kvmppc_alloc_hpt(kvm, htab_orderp); 143 order = *htab_orderp; 144 } 145 out: 146 mutex_unlock(&kvm->lock); 147 return err; 148 } 149 150 void kvmppc_free_hpt(struct kvm *kvm) 151 { 152 kvmppc_free_lpid(kvm->arch.lpid); 153 vfree(kvm->arch.revmap); 154 if (kvm->arch.hpt_cma_alloc) 155 kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt), 156 1 << (kvm->arch.hpt_order - PAGE_SHIFT)); 157 else 158 free_pages(kvm->arch.hpt_virt, 159 kvm->arch.hpt_order - PAGE_SHIFT); 160 } 161 162 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */ 163 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize) 164 { 165 return (pgsize > 0x1000) ? HPTE_V_LARGE : 0; 166 } 167 168 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */ 169 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize) 170 { 171 return (pgsize == 0x10000) ? 0x1000 : 0; 172 } 173 174 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, 175 unsigned long porder) 176 { 177 unsigned long i; 178 unsigned long npages; 179 unsigned long hp_v, hp_r; 180 unsigned long addr, hash; 181 unsigned long psize; 182 unsigned long hp0, hp1; 183 unsigned long idx_ret; 184 long ret; 185 struct kvm *kvm = vcpu->kvm; 186 187 psize = 1ul << porder; 188 npages = memslot->npages >> (porder - PAGE_SHIFT); 189 190 /* VRMA can't be > 1TB */ 191 if (npages > 1ul << (40 - porder)) 192 npages = 1ul << (40 - porder); 193 /* Can't use more than 1 HPTE per HPTEG */ 194 if (npages > kvm->arch.hpt_mask + 1) 195 npages = kvm->arch.hpt_mask + 1; 196 197 hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) | 198 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize); 199 hp1 = hpte1_pgsize_encoding(psize) | 200 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX; 201 202 for (i = 0; i < npages; ++i) { 203 addr = i << porder; 204 /* can't use hpt_hash since va > 64 bits */ 205 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask; 206 /* 207 * We assume that the hash table is empty and no 208 * vcpus are using it at this stage. Since we create 209 * at most one HPTE per HPTEG, we just assume entry 7 210 * is available and use it. 211 */ 212 hash = (hash << 3) + 7; 213 hp_v = hp0 | ((addr >> 16) & ~0x7fUL); 214 hp_r = hp1 | addr; 215 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r, 216 &idx_ret); 217 if (ret != H_SUCCESS) { 218 pr_err("KVM: map_vrma at %lx failed, ret=%ld\n", 219 addr, ret); 220 break; 221 } 222 } 223 } 224 225 int kvmppc_mmu_hv_init(void) 226 { 227 unsigned long host_lpid, rsvd_lpid; 228 229 if (!cpu_has_feature(CPU_FTR_HVMODE)) 230 return -EINVAL; 231 232 /* POWER7 has 10-bit LPIDs (12-bit in POWER8) */ 233 host_lpid = mfspr(SPRN_LPID); 234 rsvd_lpid = LPID_RSVD; 235 236 kvmppc_init_lpid(rsvd_lpid + 1); 237 238 kvmppc_claim_lpid(host_lpid); 239 /* rsvd_lpid is reserved for use in partition switching */ 240 kvmppc_claim_lpid(rsvd_lpid); 241 242 return 0; 243 } 244 245 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu) 246 { 247 unsigned long msr = vcpu->arch.intr_msr; 248 249 /* If transactional, change to suspend mode on IRQ delivery */ 250 if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr)) 251 msr |= MSR_TS_S; 252 else 253 msr |= vcpu->arch.shregs.msr & MSR_TS_MASK; 254 kvmppc_set_msr(vcpu, msr); 255 } 256 257 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 258 long pte_index, unsigned long pteh, 259 unsigned long ptel, unsigned long *pte_idx_ret) 260 { 261 long ret; 262 263 /* Protect linux PTE lookup from page table destruction */ 264 rcu_read_lock_sched(); /* this disables preemption too */ 265 ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel, 266 current->mm->pgd, false, pte_idx_ret); 267 rcu_read_unlock_sched(); 268 if (ret == H_TOO_HARD) { 269 /* this can't happen */ 270 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n"); 271 ret = H_RESOURCE; /* or something */ 272 } 273 return ret; 274 275 } 276 277 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu, 278 gva_t eaddr) 279 { 280 u64 mask; 281 int i; 282 283 for (i = 0; i < vcpu->arch.slb_nr; i++) { 284 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V)) 285 continue; 286 287 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T) 288 mask = ESID_MASK_1T; 289 else 290 mask = ESID_MASK; 291 292 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0) 293 return &vcpu->arch.slb[i]; 294 } 295 return NULL; 296 } 297 298 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r, 299 unsigned long ea) 300 { 301 unsigned long ra_mask; 302 303 ra_mask = hpte_page_size(v, r) - 1; 304 return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask); 305 } 306 307 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, 308 struct kvmppc_pte *gpte, bool data, bool iswrite) 309 { 310 struct kvm *kvm = vcpu->kvm; 311 struct kvmppc_slb *slbe; 312 unsigned long slb_v; 313 unsigned long pp, key; 314 unsigned long v, gr; 315 __be64 *hptep; 316 int index; 317 int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR); 318 319 /* Get SLB entry */ 320 if (virtmode) { 321 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr); 322 if (!slbe) 323 return -EINVAL; 324 slb_v = slbe->origv; 325 } else { 326 /* real mode access */ 327 slb_v = vcpu->kvm->arch.vrma_slb_v; 328 } 329 330 preempt_disable(); 331 /* Find the HPTE in the hash table */ 332 index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, 333 HPTE_V_VALID | HPTE_V_ABSENT); 334 if (index < 0) { 335 preempt_enable(); 336 return -ENOENT; 337 } 338 hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4)); 339 v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK; 340 gr = kvm->arch.revmap[index].guest_rpte; 341 342 unlock_hpte(hptep, v); 343 preempt_enable(); 344 345 gpte->eaddr = eaddr; 346 gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff); 347 348 /* Get PP bits and key for permission check */ 349 pp = gr & (HPTE_R_PP0 | HPTE_R_PP); 350 key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS; 351 key &= slb_v; 352 353 /* Calculate permissions */ 354 gpte->may_read = hpte_read_permission(pp, key); 355 gpte->may_write = hpte_write_permission(pp, key); 356 gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G)); 357 358 /* Storage key permission check for POWER7 */ 359 if (data && virtmode) { 360 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr); 361 if (amrfield & 1) 362 gpte->may_read = 0; 363 if (amrfield & 2) 364 gpte->may_write = 0; 365 } 366 367 /* Get the guest physical address */ 368 gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr); 369 return 0; 370 } 371 372 /* 373 * Quick test for whether an instruction is a load or a store. 374 * If the instruction is a load or a store, then this will indicate 375 * which it is, at least on server processors. (Embedded processors 376 * have some external PID instructions that don't follow the rule 377 * embodied here.) If the instruction isn't a load or store, then 378 * this doesn't return anything useful. 379 */ 380 static int instruction_is_store(unsigned int instr) 381 { 382 unsigned int mask; 383 384 mask = 0x10000000; 385 if ((instr & 0xfc000000) == 0x7c000000) 386 mask = 0x100; /* major opcode 31 */ 387 return (instr & mask) != 0; 388 } 389 390 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, 391 unsigned long gpa, gva_t ea, int is_store) 392 { 393 u32 last_inst; 394 395 /* 396 * If we fail, we just return to the guest and try executing it again. 397 */ 398 if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != 399 EMULATE_DONE) 400 return RESUME_GUEST; 401 402 /* 403 * WARNING: We do not know for sure whether the instruction we just 404 * read from memory is the same that caused the fault in the first 405 * place. If the instruction we read is neither an load or a store, 406 * then it can't access memory, so we don't need to worry about 407 * enforcing access permissions. So, assuming it is a load or 408 * store, we just check that its direction (load or store) is 409 * consistent with the original fault, since that's what we 410 * checked the access permissions against. If there is a mismatch 411 * we just return and retry the instruction. 412 */ 413 414 if (instruction_is_store(last_inst) != !!is_store) 415 return RESUME_GUEST; 416 417 /* 418 * Emulated accesses are emulated by looking at the hash for 419 * translation once, then performing the access later. The 420 * translation could be invalidated in the meantime in which 421 * point performing the subsequent memory access on the old 422 * physical address could possibly be a security hole for the 423 * guest (but not the host). 424 * 425 * This is less of an issue for MMIO stores since they aren't 426 * globally visible. It could be an issue for MMIO loads to 427 * a certain extent but we'll ignore it for now. 428 */ 429 430 vcpu->arch.paddr_accessed = gpa; 431 vcpu->arch.vaddr_accessed = ea; 432 return kvmppc_emulate_mmio(run, vcpu); 433 } 434 435 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 436 unsigned long ea, unsigned long dsisr) 437 { 438 struct kvm *kvm = vcpu->kvm; 439 unsigned long hpte[3], r; 440 __be64 *hptep; 441 unsigned long mmu_seq, psize, pte_size; 442 unsigned long gpa_base, gfn_base; 443 unsigned long gpa, gfn, hva, pfn; 444 struct kvm_memory_slot *memslot; 445 unsigned long *rmap; 446 struct revmap_entry *rev; 447 struct page *page, *pages[1]; 448 long index, ret, npages; 449 unsigned long is_io; 450 unsigned int writing, write_ok; 451 struct vm_area_struct *vma; 452 unsigned long rcbits; 453 454 /* 455 * Real-mode code has already searched the HPT and found the 456 * entry we're interested in. Lock the entry and check that 457 * it hasn't changed. If it has, just return and re-execute the 458 * instruction. 459 */ 460 if (ea != vcpu->arch.pgfault_addr) 461 return RESUME_GUEST; 462 index = vcpu->arch.pgfault_index; 463 hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4)); 464 rev = &kvm->arch.revmap[index]; 465 preempt_disable(); 466 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 467 cpu_relax(); 468 hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK; 469 hpte[1] = be64_to_cpu(hptep[1]); 470 hpte[2] = r = rev->guest_rpte; 471 unlock_hpte(hptep, hpte[0]); 472 preempt_enable(); 473 474 if (hpte[0] != vcpu->arch.pgfault_hpte[0] || 475 hpte[1] != vcpu->arch.pgfault_hpte[1]) 476 return RESUME_GUEST; 477 478 /* Translate the logical address and get the page */ 479 psize = hpte_page_size(hpte[0], r); 480 gpa_base = r & HPTE_R_RPN & ~(psize - 1); 481 gfn_base = gpa_base >> PAGE_SHIFT; 482 gpa = gpa_base | (ea & (psize - 1)); 483 gfn = gpa >> PAGE_SHIFT; 484 memslot = gfn_to_memslot(kvm, gfn); 485 486 trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr); 487 488 /* No memslot means it's an emulated MMIO region */ 489 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 490 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, 491 dsisr & DSISR_ISSTORE); 492 493 /* 494 * This should never happen, because of the slot_is_aligned() 495 * check in kvmppc_do_h_enter(). 496 */ 497 if (gfn_base < memslot->base_gfn) 498 return -EFAULT; 499 500 /* used to check for invalidations in progress */ 501 mmu_seq = kvm->mmu_notifier_seq; 502 smp_rmb(); 503 504 ret = -EFAULT; 505 is_io = 0; 506 pfn = 0; 507 page = NULL; 508 pte_size = PAGE_SIZE; 509 writing = (dsisr & DSISR_ISSTORE) != 0; 510 /* If writing != 0, then the HPTE must allow writing, if we get here */ 511 write_ok = writing; 512 hva = gfn_to_hva_memslot(memslot, gfn); 513 npages = get_user_pages_fast(hva, 1, writing, pages); 514 if (npages < 1) { 515 /* Check if it's an I/O mapping */ 516 down_read(¤t->mm->mmap_sem); 517 vma = find_vma(current->mm, hva); 518 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end && 519 (vma->vm_flags & VM_PFNMAP)) { 520 pfn = vma->vm_pgoff + 521 ((hva - vma->vm_start) >> PAGE_SHIFT); 522 pte_size = psize; 523 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot)); 524 write_ok = vma->vm_flags & VM_WRITE; 525 } 526 up_read(¤t->mm->mmap_sem); 527 if (!pfn) 528 goto out_put; 529 } else { 530 page = pages[0]; 531 pfn = page_to_pfn(page); 532 if (PageHuge(page)) { 533 page = compound_head(page); 534 pte_size <<= compound_order(page); 535 } 536 /* if the guest wants write access, see if that is OK */ 537 if (!writing && hpte_is_writable(r)) { 538 pte_t *ptep, pte; 539 unsigned long flags; 540 /* 541 * We need to protect against page table destruction 542 * hugepage split and collapse. 543 */ 544 local_irq_save(flags); 545 ptep = find_linux_pte_or_hugepte(current->mm->pgd, 546 hva, NULL); 547 if (ptep) { 548 pte = kvmppc_read_update_linux_pte(ptep, 1); 549 if (pte_write(pte)) 550 write_ok = 1; 551 } 552 local_irq_restore(flags); 553 } 554 } 555 556 if (psize > pte_size) 557 goto out_put; 558 559 /* Check WIMG vs. the actual page we're accessing */ 560 if (!hpte_cache_flags_ok(r, is_io)) { 561 if (is_io) 562 goto out_put; 563 564 /* 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; 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 & ~rev[i].guest_rpte) { 765 rev[i].guest_rpte = ptel | rcbits; 766 note_hpte_modification(kvm, &rev[i]); 767 } 768 } 769 unlock_rmap(rmapp); 770 __unlock_hpte(hptep, be64_to_cpu(hptep[0])); 771 } 772 return 0; 773 } 774 775 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva) 776 { 777 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 778 return 0; 779 } 780 781 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end) 782 { 783 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp); 784 return 0; 785 } 786 787 void kvmppc_core_flush_memslot_hv(struct kvm *kvm, 788 struct kvm_memory_slot *memslot) 789 { 790 unsigned long *rmapp; 791 unsigned long gfn; 792 unsigned long n; 793 794 rmapp = memslot->arch.rmap; 795 gfn = memslot->base_gfn; 796 for (n = memslot->npages; n; --n) { 797 /* 798 * Testing the present bit without locking is OK because 799 * the memslot has been marked invalid already, and hence 800 * no new HPTEs referencing this page can be created, 801 * thus the present bit can't go from 0 to 1. 802 */ 803 if (*rmapp & KVMPPC_RMAP_PRESENT) 804 kvm_unmap_rmapp(kvm, rmapp, gfn); 805 ++rmapp; 806 ++gfn; 807 } 808 } 809 810 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 811 unsigned long gfn) 812 { 813 struct revmap_entry *rev = kvm->arch.revmap; 814 unsigned long head, i, j; 815 __be64 *hptep; 816 int ret = 0; 817 818 retry: 819 lock_rmap(rmapp); 820 if (*rmapp & KVMPPC_RMAP_REFERENCED) { 821 *rmapp &= ~KVMPPC_RMAP_REFERENCED; 822 ret = 1; 823 } 824 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 825 unlock_rmap(rmapp); 826 return ret; 827 } 828 829 i = head = *rmapp & KVMPPC_RMAP_INDEX; 830 do { 831 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4)); 832 j = rev[i].forw; 833 834 /* If this HPTE isn't referenced, ignore it */ 835 if (!(be64_to_cpu(hptep[1]) & HPTE_R_R)) 836 continue; 837 838 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 839 /* unlock rmap before spinning on the HPTE lock */ 840 unlock_rmap(rmapp); 841 while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK) 842 cpu_relax(); 843 goto retry; 844 } 845 846 /* Now check and modify the HPTE */ 847 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) && 848 (be64_to_cpu(hptep[1]) & HPTE_R_R)) { 849 kvmppc_clear_ref_hpte(kvm, hptep, i); 850 if (!(rev[i].guest_rpte & HPTE_R_R)) { 851 rev[i].guest_rpte |= HPTE_R_R; 852 note_hpte_modification(kvm, &rev[i]); 853 } 854 ret = 1; 855 } 856 __unlock_hpte(hptep, be64_to_cpu(hptep[0])); 857 } while ((i = j) != head); 858 859 unlock_rmap(rmapp); 860 return ret; 861 } 862 863 int kvm_age_hva_hv(struct kvm *kvm, unsigned long start, unsigned long end) 864 { 865 return kvm_handle_hva_range(kvm, start, end, kvm_age_rmapp); 866 } 867 868 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 869 unsigned long gfn) 870 { 871 struct revmap_entry *rev = kvm->arch.revmap; 872 unsigned long head, i, j; 873 unsigned long *hp; 874 int ret = 1; 875 876 if (*rmapp & KVMPPC_RMAP_REFERENCED) 877 return 1; 878 879 lock_rmap(rmapp); 880 if (*rmapp & KVMPPC_RMAP_REFERENCED) 881 goto out; 882 883 if (*rmapp & KVMPPC_RMAP_PRESENT) { 884 i = head = *rmapp & KVMPPC_RMAP_INDEX; 885 do { 886 hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4)); 887 j = rev[i].forw; 888 if (be64_to_cpu(hp[1]) & HPTE_R_R) 889 goto out; 890 } while ((i = j) != head); 891 } 892 ret = 0; 893 894 out: 895 unlock_rmap(rmapp); 896 return ret; 897 } 898 899 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva) 900 { 901 return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp); 902 } 903 904 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte) 905 { 906 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 907 } 908 909 static int vcpus_running(struct kvm *kvm) 910 { 911 return atomic_read(&kvm->arch.vcpus_running) != 0; 912 } 913 914 /* 915 * Returns the number of system pages that are dirty. 916 * This can be more than 1 if we find a huge-page HPTE. 917 */ 918 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp) 919 { 920 struct revmap_entry *rev = kvm->arch.revmap; 921 unsigned long head, i, j; 922 unsigned long n; 923 unsigned long v, r; 924 __be64 *hptep; 925 int npages_dirty = 0; 926 927 retry: 928 lock_rmap(rmapp); 929 if (*rmapp & KVMPPC_RMAP_CHANGED) { 930 *rmapp &= ~KVMPPC_RMAP_CHANGED; 931 npages_dirty = 1; 932 } 933 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 934 unlock_rmap(rmapp); 935 return npages_dirty; 936 } 937 938 i = head = *rmapp & KVMPPC_RMAP_INDEX; 939 do { 940 unsigned long hptep1; 941 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4)); 942 j = rev[i].forw; 943 944 /* 945 * Checking the C (changed) bit here is racy since there 946 * is no guarantee about when the hardware writes it back. 947 * If the HPTE is not writable then it is stable since the 948 * page can't be written to, and we would have done a tlbie 949 * (which forces the hardware to complete any writeback) 950 * when making the HPTE read-only. 951 * If vcpus are running then this call is racy anyway 952 * since the page could get dirtied subsequently, so we 953 * expect there to be a further call which would pick up 954 * any delayed C bit writeback. 955 * Otherwise we need to do the tlbie even if C==0 in 956 * order to pick up any delayed writeback of C. 957 */ 958 hptep1 = be64_to_cpu(hptep[1]); 959 if (!(hptep1 & HPTE_R_C) && 960 (!hpte_is_writable(hptep1) || vcpus_running(kvm))) 961 continue; 962 963 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 964 /* unlock rmap before spinning on the HPTE lock */ 965 unlock_rmap(rmapp); 966 while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK)) 967 cpu_relax(); 968 goto retry; 969 } 970 971 /* Now check and modify the HPTE */ 972 if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) { 973 __unlock_hpte(hptep, be64_to_cpu(hptep[0])); 974 continue; 975 } 976 977 /* need to make it temporarily absent so C is stable */ 978 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT); 979 kvmppc_invalidate_hpte(kvm, hptep, i); 980 v = be64_to_cpu(hptep[0]); 981 r = be64_to_cpu(hptep[1]); 982 if (r & HPTE_R_C) { 983 hptep[1] = cpu_to_be64(r & ~HPTE_R_C); 984 if (!(rev[i].guest_rpte & HPTE_R_C)) { 985 rev[i].guest_rpte |= HPTE_R_C; 986 note_hpte_modification(kvm, &rev[i]); 987 } 988 n = hpte_page_size(v, r); 989 n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT; 990 if (n > npages_dirty) 991 npages_dirty = n; 992 eieio(); 993 } 994 v &= ~HPTE_V_ABSENT; 995 v |= HPTE_V_VALID; 996 __unlock_hpte(hptep, v); 997 } while ((i = j) != head); 998 999 unlock_rmap(rmapp); 1000 return npages_dirty; 1001 } 1002 1003 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, 1004 struct kvm_memory_slot *memslot, 1005 unsigned long *map) 1006 { 1007 unsigned long gfn; 1008 1009 if (!vpa->dirty || !vpa->pinned_addr) 1010 return; 1011 gfn = vpa->gpa >> PAGE_SHIFT; 1012 if (gfn < memslot->base_gfn || 1013 gfn >= memslot->base_gfn + memslot->npages) 1014 return; 1015 1016 vpa->dirty = false; 1017 if (map) 1018 __set_bit_le(gfn - memslot->base_gfn, map); 1019 } 1020 1021 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, 1022 unsigned long *map) 1023 { 1024 unsigned long i, j; 1025 unsigned long *rmapp; 1026 struct kvm_vcpu *vcpu; 1027 1028 preempt_disable(); 1029 rmapp = memslot->arch.rmap; 1030 for (i = 0; i < memslot->npages; ++i) { 1031 int npages = kvm_test_clear_dirty_npages(kvm, rmapp); 1032 /* 1033 * Note that if npages > 0 then i must be a multiple of npages, 1034 * since we always put huge-page HPTEs in the rmap chain 1035 * corresponding to their page base address. 1036 */ 1037 if (npages && map) 1038 for (j = i; npages; ++j, --npages) 1039 __set_bit_le(j, map); 1040 ++rmapp; 1041 } 1042 1043 /* Harvest dirty bits from VPA and DTL updates */ 1044 /* Note: we never modify the SLB shadow buffer areas */ 1045 kvm_for_each_vcpu(i, vcpu, kvm) { 1046 spin_lock(&vcpu->arch.vpa_update_lock); 1047 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map); 1048 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map); 1049 spin_unlock(&vcpu->arch.vpa_update_lock); 1050 } 1051 preempt_enable(); 1052 return 0; 1053 } 1054 1055 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, 1056 unsigned long *nb_ret) 1057 { 1058 struct kvm_memory_slot *memslot; 1059 unsigned long gfn = gpa >> PAGE_SHIFT; 1060 struct page *page, *pages[1]; 1061 int npages; 1062 unsigned long hva, offset; 1063 int srcu_idx; 1064 1065 srcu_idx = srcu_read_lock(&kvm->srcu); 1066 memslot = gfn_to_memslot(kvm, gfn); 1067 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 1068 goto err; 1069 hva = gfn_to_hva_memslot(memslot, gfn); 1070 npages = get_user_pages_fast(hva, 1, 1, pages); 1071 if (npages < 1) 1072 goto err; 1073 page = pages[0]; 1074 srcu_read_unlock(&kvm->srcu, srcu_idx); 1075 1076 offset = gpa & (PAGE_SIZE - 1); 1077 if (nb_ret) 1078 *nb_ret = PAGE_SIZE - offset; 1079 return page_address(page) + offset; 1080 1081 err: 1082 srcu_read_unlock(&kvm->srcu, srcu_idx); 1083 return NULL; 1084 } 1085 1086 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa, 1087 bool dirty) 1088 { 1089 struct page *page = virt_to_page(va); 1090 struct kvm_memory_slot *memslot; 1091 unsigned long gfn; 1092 unsigned long *rmap; 1093 int srcu_idx; 1094 1095 put_page(page); 1096 1097 if (!dirty) 1098 return; 1099 1100 /* We need to mark this page dirty in the rmap chain */ 1101 gfn = gpa >> PAGE_SHIFT; 1102 srcu_idx = srcu_read_lock(&kvm->srcu); 1103 memslot = gfn_to_memslot(kvm, gfn); 1104 if (memslot) { 1105 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 1106 lock_rmap(rmap); 1107 *rmap |= KVMPPC_RMAP_CHANGED; 1108 unlock_rmap(rmap); 1109 } 1110 srcu_read_unlock(&kvm->srcu, srcu_idx); 1111 } 1112 1113 /* 1114 * Functions for reading and writing the hash table via reads and 1115 * writes on a file descriptor. 1116 * 1117 * Reads return the guest view of the hash table, which has to be 1118 * pieced together from the real hash table and the guest_rpte 1119 * values in the revmap array. 1120 * 1121 * On writes, each HPTE written is considered in turn, and if it 1122 * is valid, it is written to the HPT as if an H_ENTER with the 1123 * exact flag set was done. When the invalid count is non-zero 1124 * in the header written to the stream, the kernel will make 1125 * sure that that many HPTEs are invalid, and invalidate them 1126 * if not. 1127 */ 1128 1129 struct kvm_htab_ctx { 1130 unsigned long index; 1131 unsigned long flags; 1132 struct kvm *kvm; 1133 int first_pass; 1134 }; 1135 1136 #define HPTE_SIZE (2 * sizeof(unsigned long)) 1137 1138 /* 1139 * Returns 1 if this HPT entry has been modified or has pending 1140 * R/C bit changes. 1141 */ 1142 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp) 1143 { 1144 unsigned long rcbits_unset; 1145 1146 if (revp->guest_rpte & HPTE_GR_MODIFIED) 1147 return 1; 1148 1149 /* Also need to consider changes in reference and changed bits */ 1150 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1151 if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) && 1152 (be64_to_cpu(hptp[1]) & rcbits_unset)) 1153 return 1; 1154 1155 return 0; 1156 } 1157 1158 static long record_hpte(unsigned long flags, __be64 *hptp, 1159 unsigned long *hpte, struct revmap_entry *revp, 1160 int want_valid, int first_pass) 1161 { 1162 unsigned long v, r; 1163 unsigned long rcbits_unset; 1164 int ok = 1; 1165 int valid, dirty; 1166 1167 /* Unmodified entries are uninteresting except on the first pass */ 1168 dirty = hpte_dirty(revp, hptp); 1169 if (!first_pass && !dirty) 1170 return 0; 1171 1172 valid = 0; 1173 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) { 1174 valid = 1; 1175 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && 1176 !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED)) 1177 valid = 0; 1178 } 1179 if (valid != want_valid) 1180 return 0; 1181 1182 v = r = 0; 1183 if (valid || dirty) { 1184 /* lock the HPTE so it's stable and read it */ 1185 preempt_disable(); 1186 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) 1187 cpu_relax(); 1188 v = be64_to_cpu(hptp[0]); 1189 1190 /* re-evaluate valid and dirty from synchronized HPTE value */ 1191 valid = !!(v & HPTE_V_VALID); 1192 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); 1193 1194 /* Harvest R and C into guest view if necessary */ 1195 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1196 if (valid && (rcbits_unset & be64_to_cpu(hptp[1]))) { 1197 revp->guest_rpte |= (be64_to_cpu(hptp[1]) & 1198 (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED; 1199 dirty = 1; 1200 } 1201 1202 if (v & HPTE_V_ABSENT) { 1203 v &= ~HPTE_V_ABSENT; 1204 v |= HPTE_V_VALID; 1205 valid = 1; 1206 } 1207 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) 1208 valid = 0; 1209 1210 r = revp->guest_rpte; 1211 /* only clear modified if this is the right sort of entry */ 1212 if (valid == want_valid && dirty) { 1213 r &= ~HPTE_GR_MODIFIED; 1214 revp->guest_rpte = r; 1215 } 1216 unlock_hpte(hptp, be64_to_cpu(hptp[0])); 1217 preempt_enable(); 1218 if (!(valid == want_valid && (first_pass || dirty))) 1219 ok = 0; 1220 } 1221 hpte[0] = cpu_to_be64(v); 1222 hpte[1] = cpu_to_be64(r); 1223 return ok; 1224 } 1225 1226 static ssize_t kvm_htab_read(struct file *file, char __user *buf, 1227 size_t count, loff_t *ppos) 1228 { 1229 struct kvm_htab_ctx *ctx = file->private_data; 1230 struct kvm *kvm = ctx->kvm; 1231 struct kvm_get_htab_header hdr; 1232 __be64 *hptp; 1233 struct revmap_entry *revp; 1234 unsigned long i, nb, nw; 1235 unsigned long __user *lbuf; 1236 struct kvm_get_htab_header __user *hptr; 1237 unsigned long flags; 1238 int first_pass; 1239 unsigned long hpte[2]; 1240 1241 if (!access_ok(VERIFY_WRITE, buf, count)) 1242 return -EFAULT; 1243 1244 first_pass = ctx->first_pass; 1245 flags = ctx->flags; 1246 1247 i = ctx->index; 1248 hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1249 revp = kvm->arch.revmap + i; 1250 lbuf = (unsigned long __user *)buf; 1251 1252 nb = 0; 1253 while (nb + sizeof(hdr) + HPTE_SIZE < count) { 1254 /* Initialize header */ 1255 hptr = (struct kvm_get_htab_header __user *)buf; 1256 hdr.n_valid = 0; 1257 hdr.n_invalid = 0; 1258 nw = nb; 1259 nb += sizeof(hdr); 1260 lbuf = (unsigned long __user *)(buf + sizeof(hdr)); 1261 1262 /* Skip uninteresting entries, i.e. clean on not-first pass */ 1263 if (!first_pass) { 1264 while (i < kvm->arch.hpt_npte && 1265 !hpte_dirty(revp, hptp)) { 1266 ++i; 1267 hptp += 2; 1268 ++revp; 1269 } 1270 } 1271 hdr.index = i; 1272 1273 /* Grab a series of valid entries */ 1274 while (i < kvm->arch.hpt_npte && 1275 hdr.n_valid < 0xffff && 1276 nb + HPTE_SIZE < count && 1277 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) { 1278 /* valid entry, write it out */ 1279 ++hdr.n_valid; 1280 if (__put_user(hpte[0], lbuf) || 1281 __put_user(hpte[1], lbuf + 1)) 1282 return -EFAULT; 1283 nb += HPTE_SIZE; 1284 lbuf += 2; 1285 ++i; 1286 hptp += 2; 1287 ++revp; 1288 } 1289 /* Now skip invalid entries while we can */ 1290 while (i < kvm->arch.hpt_npte && 1291 hdr.n_invalid < 0xffff && 1292 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) { 1293 /* found an invalid entry */ 1294 ++hdr.n_invalid; 1295 ++i; 1296 hptp += 2; 1297 ++revp; 1298 } 1299 1300 if (hdr.n_valid || hdr.n_invalid) { 1301 /* write back the header */ 1302 if (__copy_to_user(hptr, &hdr, sizeof(hdr))) 1303 return -EFAULT; 1304 nw = nb; 1305 buf = (char __user *)lbuf; 1306 } else { 1307 nb = nw; 1308 } 1309 1310 /* Check if we've wrapped around the hash table */ 1311 if (i >= kvm->arch.hpt_npte) { 1312 i = 0; 1313 ctx->first_pass = 0; 1314 break; 1315 } 1316 } 1317 1318 ctx->index = i; 1319 1320 return nb; 1321 } 1322 1323 static ssize_t kvm_htab_write(struct file *file, const char __user *buf, 1324 size_t count, loff_t *ppos) 1325 { 1326 struct kvm_htab_ctx *ctx = file->private_data; 1327 struct kvm *kvm = ctx->kvm; 1328 struct kvm_get_htab_header hdr; 1329 unsigned long i, j; 1330 unsigned long v, r; 1331 unsigned long __user *lbuf; 1332 __be64 *hptp; 1333 unsigned long tmp[2]; 1334 ssize_t nb; 1335 long int err, ret; 1336 int hpte_setup; 1337 1338 if (!access_ok(VERIFY_READ, buf, count)) 1339 return -EFAULT; 1340 1341 /* lock out vcpus from running while we're doing this */ 1342 mutex_lock(&kvm->lock); 1343 hpte_setup = kvm->arch.hpte_setup_done; 1344 if (hpte_setup) { 1345 kvm->arch.hpte_setup_done = 0; /* temporarily */ 1346 /* order hpte_setup_done vs. vcpus_running */ 1347 smp_mb(); 1348 if (atomic_read(&kvm->arch.vcpus_running)) { 1349 kvm->arch.hpte_setup_done = 1; 1350 mutex_unlock(&kvm->lock); 1351 return -EBUSY; 1352 } 1353 } 1354 1355 err = 0; 1356 for (nb = 0; nb + sizeof(hdr) <= count; ) { 1357 err = -EFAULT; 1358 if (__copy_from_user(&hdr, buf, sizeof(hdr))) 1359 break; 1360 1361 err = 0; 1362 if (nb + hdr.n_valid * HPTE_SIZE > count) 1363 break; 1364 1365 nb += sizeof(hdr); 1366 buf += sizeof(hdr); 1367 1368 err = -EINVAL; 1369 i = hdr.index; 1370 if (i >= kvm->arch.hpt_npte || 1371 i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte) 1372 break; 1373 1374 hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1375 lbuf = (unsigned long __user *)buf; 1376 for (j = 0; j < hdr.n_valid; ++j) { 1377 __be64 hpte_v; 1378 __be64 hpte_r; 1379 1380 err = -EFAULT; 1381 if (__get_user(hpte_v, lbuf) || 1382 __get_user(hpte_r, lbuf + 1)) 1383 goto out; 1384 v = be64_to_cpu(hpte_v); 1385 r = be64_to_cpu(hpte_r); 1386 err = -EINVAL; 1387 if (!(v & HPTE_V_VALID)) 1388 goto out; 1389 lbuf += 2; 1390 nb += HPTE_SIZE; 1391 1392 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) 1393 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1394 err = -EIO; 1395 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r, 1396 tmp); 1397 if (ret != H_SUCCESS) { 1398 pr_err("kvm_htab_write ret %ld i=%ld v=%lx " 1399 "r=%lx\n", ret, i, v, r); 1400 goto out; 1401 } 1402 if (!hpte_setup && is_vrma_hpte(v)) { 1403 unsigned long psize = hpte_base_page_size(v, r); 1404 unsigned long senc = slb_pgsize_encoding(psize); 1405 unsigned long lpcr; 1406 1407 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T | 1408 (VRMA_VSID << SLB_VSID_SHIFT_1T); 1409 lpcr = senc << (LPCR_VRMASD_SH - 4); 1410 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD); 1411 hpte_setup = 1; 1412 } 1413 ++i; 1414 hptp += 2; 1415 } 1416 1417 for (j = 0; j < hdr.n_invalid; ++j) { 1418 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) 1419 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1420 ++i; 1421 hptp += 2; 1422 } 1423 err = 0; 1424 } 1425 1426 out: 1427 /* Order HPTE updates vs. hpte_setup_done */ 1428 smp_wmb(); 1429 kvm->arch.hpte_setup_done = hpte_setup; 1430 mutex_unlock(&kvm->lock); 1431 1432 if (err) 1433 return err; 1434 return nb; 1435 } 1436 1437 static int kvm_htab_release(struct inode *inode, struct file *filp) 1438 { 1439 struct kvm_htab_ctx *ctx = filp->private_data; 1440 1441 filp->private_data = NULL; 1442 if (!(ctx->flags & KVM_GET_HTAB_WRITE)) 1443 atomic_dec(&ctx->kvm->arch.hpte_mod_interest); 1444 kvm_put_kvm(ctx->kvm); 1445 kfree(ctx); 1446 return 0; 1447 } 1448 1449 static const struct file_operations kvm_htab_fops = { 1450 .read = kvm_htab_read, 1451 .write = kvm_htab_write, 1452 .llseek = default_llseek, 1453 .release = kvm_htab_release, 1454 }; 1455 1456 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf) 1457 { 1458 int ret; 1459 struct kvm_htab_ctx *ctx; 1460 int rwflag; 1461 1462 /* reject flags we don't recognize */ 1463 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE)) 1464 return -EINVAL; 1465 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 1466 if (!ctx) 1467 return -ENOMEM; 1468 kvm_get_kvm(kvm); 1469 ctx->kvm = kvm; 1470 ctx->index = ghf->start_index; 1471 ctx->flags = ghf->flags; 1472 ctx->first_pass = 1; 1473 1474 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY; 1475 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC); 1476 if (ret < 0) { 1477 kvm_put_kvm(kvm); 1478 return ret; 1479 } 1480 1481 if (rwflag == O_RDONLY) { 1482 mutex_lock(&kvm->slots_lock); 1483 atomic_inc(&kvm->arch.hpte_mod_interest); 1484 /* make sure kvmppc_do_h_enter etc. see the increment */ 1485 synchronize_srcu_expedited(&kvm->srcu); 1486 mutex_unlock(&kvm->slots_lock); 1487 } 1488 1489 return ret; 1490 } 1491 1492 struct debugfs_htab_state { 1493 struct kvm *kvm; 1494 struct mutex mutex; 1495 unsigned long hpt_index; 1496 int chars_left; 1497 int buf_index; 1498 char buf[64]; 1499 }; 1500 1501 static int debugfs_htab_open(struct inode *inode, struct file *file) 1502 { 1503 struct kvm *kvm = inode->i_private; 1504 struct debugfs_htab_state *p; 1505 1506 p = kzalloc(sizeof(*p), GFP_KERNEL); 1507 if (!p) 1508 return -ENOMEM; 1509 1510 kvm_get_kvm(kvm); 1511 p->kvm = kvm; 1512 mutex_init(&p->mutex); 1513 file->private_data = p; 1514 1515 return nonseekable_open(inode, file); 1516 } 1517 1518 static int debugfs_htab_release(struct inode *inode, struct file *file) 1519 { 1520 struct debugfs_htab_state *p = file->private_data; 1521 1522 kvm_put_kvm(p->kvm); 1523 kfree(p); 1524 return 0; 1525 } 1526 1527 static ssize_t debugfs_htab_read(struct file *file, char __user *buf, 1528 size_t len, loff_t *ppos) 1529 { 1530 struct debugfs_htab_state *p = file->private_data; 1531 ssize_t ret, r; 1532 unsigned long i, n; 1533 unsigned long v, hr, gr; 1534 struct kvm *kvm; 1535 __be64 *hptp; 1536 1537 ret = mutex_lock_interruptible(&p->mutex); 1538 if (ret) 1539 return ret; 1540 1541 if (p->chars_left) { 1542 n = p->chars_left; 1543 if (n > len) 1544 n = len; 1545 r = copy_to_user(buf, p->buf + p->buf_index, n); 1546 n -= r; 1547 p->chars_left -= n; 1548 p->buf_index += n; 1549 buf += n; 1550 len -= n; 1551 ret = n; 1552 if (r) { 1553 if (!n) 1554 ret = -EFAULT; 1555 goto out; 1556 } 1557 } 1558 1559 kvm = p->kvm; 1560 i = p->hpt_index; 1561 hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1562 for (; len != 0 && i < kvm->arch.hpt_npte; ++i, hptp += 2) { 1563 if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))) 1564 continue; 1565 1566 /* lock the HPTE so it's stable and read it */ 1567 preempt_disable(); 1568 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) 1569 cpu_relax(); 1570 v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK; 1571 hr = be64_to_cpu(hptp[1]); 1572 gr = kvm->arch.revmap[i].guest_rpte; 1573 unlock_hpte(hptp, v); 1574 preempt_enable(); 1575 1576 if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT))) 1577 continue; 1578 1579 n = scnprintf(p->buf, sizeof(p->buf), 1580 "%6lx %.16lx %.16lx %.16lx\n", 1581 i, v, hr, gr); 1582 p->chars_left = n; 1583 if (n > len) 1584 n = len; 1585 r = copy_to_user(buf, p->buf, n); 1586 n -= r; 1587 p->chars_left -= n; 1588 p->buf_index = n; 1589 buf += n; 1590 len -= n; 1591 ret += n; 1592 if (r) { 1593 if (!ret) 1594 ret = -EFAULT; 1595 goto out; 1596 } 1597 } 1598 p->hpt_index = i; 1599 1600 out: 1601 mutex_unlock(&p->mutex); 1602 return ret; 1603 } 1604 1605 ssize_t debugfs_htab_write(struct file *file, const char __user *buf, 1606 size_t len, loff_t *ppos) 1607 { 1608 return -EACCES; 1609 } 1610 1611 static const struct file_operations debugfs_htab_fops = { 1612 .owner = THIS_MODULE, 1613 .open = debugfs_htab_open, 1614 .release = debugfs_htab_release, 1615 .read = debugfs_htab_read, 1616 .write = debugfs_htab_write, 1617 .llseek = generic_file_llseek, 1618 }; 1619 1620 void kvmppc_mmu_debugfs_init(struct kvm *kvm) 1621 { 1622 kvm->arch.htab_dentry = debugfs_create_file("htab", 0400, 1623 kvm->arch.debugfs_dir, kvm, 1624 &debugfs_htab_fops); 1625 } 1626 1627 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) 1628 { 1629 struct kvmppc_mmu *mmu = &vcpu->arch.mmu; 1630 1631 vcpu->arch.slb_nr = 32; /* POWER7/POWER8 */ 1632 1633 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate; 1634 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr; 1635 1636 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; 1637 } 1638