1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License, version 2, as 4 * published by the Free Software Foundation. 5 * 6 * This program is distributed in the hope that it will be useful, 7 * but WITHOUT ANY WARRANTY; without even the implied warranty of 8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 9 * GNU General Public License for more details. 10 * 11 * You should have received a copy of the GNU General Public License 12 * along with this program; if not, write to the Free Software 13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 14 * 15 * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> 16 */ 17 18 #include <linux/types.h> 19 #include <linux/string.h> 20 #include <linux/kvm.h> 21 #include <linux/kvm_host.h> 22 #include <linux/highmem.h> 23 #include <linux/gfp.h> 24 #include <linux/slab.h> 25 #include <linux/hugetlb.h> 26 #include <linux/vmalloc.h> 27 #include <linux/srcu.h> 28 #include <linux/anon_inodes.h> 29 #include <linux/file.h> 30 31 #include <asm/tlbflush.h> 32 #include <asm/kvm_ppc.h> 33 #include <asm/kvm_book3s.h> 34 #include <asm/mmu-hash64.h> 35 #include <asm/hvcall.h> 36 #include <asm/synch.h> 37 #include <asm/ppc-opcode.h> 38 #include <asm/cputable.h> 39 40 /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */ 41 #define MAX_LPID_970 63 42 43 /* Power architecture requires HPT is at least 256kB */ 44 #define PPC_MIN_HPT_ORDER 18 45 46 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 47 long pte_index, unsigned long pteh, 48 unsigned long ptel, unsigned long *pte_idx_ret); 49 static void kvmppc_rmap_reset(struct kvm *kvm); 50 51 long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp) 52 { 53 unsigned long hpt; 54 struct revmap_entry *rev; 55 struct kvmppc_linear_info *li; 56 long order = kvm_hpt_order; 57 58 if (htab_orderp) { 59 order = *htab_orderp; 60 if (order < PPC_MIN_HPT_ORDER) 61 order = PPC_MIN_HPT_ORDER; 62 } 63 64 /* 65 * If the user wants a different size from default, 66 * try first to allocate it from the kernel page allocator. 67 */ 68 hpt = 0; 69 if (order != kvm_hpt_order) { 70 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT| 71 __GFP_NOWARN, order - PAGE_SHIFT); 72 if (!hpt) 73 --order; 74 } 75 76 /* Next try to allocate from the preallocated pool */ 77 if (!hpt) { 78 li = kvm_alloc_hpt(); 79 if (li) { 80 hpt = (ulong)li->base_virt; 81 kvm->arch.hpt_li = li; 82 order = kvm_hpt_order; 83 } 84 } 85 86 /* Lastly try successively smaller sizes from the page allocator */ 87 while (!hpt && order > PPC_MIN_HPT_ORDER) { 88 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT| 89 __GFP_NOWARN, order - PAGE_SHIFT); 90 if (!hpt) 91 --order; 92 } 93 94 if (!hpt) 95 return -ENOMEM; 96 97 kvm->arch.hpt_virt = hpt; 98 kvm->arch.hpt_order = order; 99 /* HPTEs are 2**4 bytes long */ 100 kvm->arch.hpt_npte = 1ul << (order - 4); 101 /* 128 (2**7) bytes in each HPTEG */ 102 kvm->arch.hpt_mask = (1ul << (order - 7)) - 1; 103 104 /* Allocate reverse map array */ 105 rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte); 106 if (!rev) { 107 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n"); 108 goto out_freehpt; 109 } 110 kvm->arch.revmap = rev; 111 kvm->arch.sdr1 = __pa(hpt) | (order - 18); 112 113 pr_info("KVM guest htab at %lx (order %ld), LPID %x\n", 114 hpt, order, kvm->arch.lpid); 115 116 if (htab_orderp) 117 *htab_orderp = order; 118 return 0; 119 120 out_freehpt: 121 if (kvm->arch.hpt_li) 122 kvm_release_hpt(kvm->arch.hpt_li); 123 else 124 free_pages(hpt, order - PAGE_SHIFT); 125 return -ENOMEM; 126 } 127 128 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp) 129 { 130 long err = -EBUSY; 131 long order; 132 133 mutex_lock(&kvm->lock); 134 if (kvm->arch.rma_setup_done) { 135 kvm->arch.rma_setup_done = 0; 136 /* order rma_setup_done vs. vcpus_running */ 137 smp_mb(); 138 if (atomic_read(&kvm->arch.vcpus_running)) { 139 kvm->arch.rma_setup_done = 1; 140 goto out; 141 } 142 } 143 if (kvm->arch.hpt_virt) { 144 order = kvm->arch.hpt_order; 145 /* Set the entire HPT to 0, i.e. invalid HPTEs */ 146 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order); 147 /* 148 * Reset all the reverse-mapping chains for all memslots 149 */ 150 kvmppc_rmap_reset(kvm); 151 /* Ensure that each vcpu will flush its TLB on next entry. */ 152 cpumask_setall(&kvm->arch.need_tlb_flush); 153 *htab_orderp = order; 154 err = 0; 155 } else { 156 err = kvmppc_alloc_hpt(kvm, htab_orderp); 157 order = *htab_orderp; 158 } 159 out: 160 mutex_unlock(&kvm->lock); 161 return err; 162 } 163 164 void kvmppc_free_hpt(struct kvm *kvm) 165 { 166 kvmppc_free_lpid(kvm->arch.lpid); 167 vfree(kvm->arch.revmap); 168 if (kvm->arch.hpt_li) 169 kvm_release_hpt(kvm->arch.hpt_li); 170 else 171 free_pages(kvm->arch.hpt_virt, 172 kvm->arch.hpt_order - PAGE_SHIFT); 173 } 174 175 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */ 176 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize) 177 { 178 return (pgsize > 0x1000) ? HPTE_V_LARGE : 0; 179 } 180 181 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */ 182 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize) 183 { 184 return (pgsize == 0x10000) ? 0x1000 : 0; 185 } 186 187 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, 188 unsigned long porder) 189 { 190 unsigned long i; 191 unsigned long npages; 192 unsigned long hp_v, hp_r; 193 unsigned long addr, hash; 194 unsigned long psize; 195 unsigned long hp0, hp1; 196 unsigned long idx_ret; 197 long ret; 198 struct kvm *kvm = vcpu->kvm; 199 200 psize = 1ul << porder; 201 npages = memslot->npages >> (porder - PAGE_SHIFT); 202 203 /* VRMA can't be > 1TB */ 204 if (npages > 1ul << (40 - porder)) 205 npages = 1ul << (40 - porder); 206 /* Can't use more than 1 HPTE per HPTEG */ 207 if (npages > kvm->arch.hpt_mask + 1) 208 npages = kvm->arch.hpt_mask + 1; 209 210 hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) | 211 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize); 212 hp1 = hpte1_pgsize_encoding(psize) | 213 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX; 214 215 for (i = 0; i < npages; ++i) { 216 addr = i << porder; 217 /* can't use hpt_hash since va > 64 bits */ 218 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask; 219 /* 220 * We assume that the hash table is empty and no 221 * vcpus are using it at this stage. Since we create 222 * at most one HPTE per HPTEG, we just assume entry 7 223 * is available and use it. 224 */ 225 hash = (hash << 3) + 7; 226 hp_v = hp0 | ((addr >> 16) & ~0x7fUL); 227 hp_r = hp1 | addr; 228 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r, 229 &idx_ret); 230 if (ret != H_SUCCESS) { 231 pr_err("KVM: map_vrma at %lx failed, ret=%ld\n", 232 addr, ret); 233 break; 234 } 235 } 236 } 237 238 int kvmppc_mmu_hv_init(void) 239 { 240 unsigned long host_lpid, rsvd_lpid; 241 242 if (!cpu_has_feature(CPU_FTR_HVMODE)) 243 return -EINVAL; 244 245 /* POWER7 has 10-bit LPIDs, PPC970 and e500mc have 6-bit LPIDs */ 246 if (cpu_has_feature(CPU_FTR_ARCH_206)) { 247 host_lpid = mfspr(SPRN_LPID); /* POWER7 */ 248 rsvd_lpid = LPID_RSVD; 249 } else { 250 host_lpid = 0; /* PPC970 */ 251 rsvd_lpid = MAX_LPID_970; 252 } 253 254 kvmppc_init_lpid(rsvd_lpid + 1); 255 256 kvmppc_claim_lpid(host_lpid); 257 /* rsvd_lpid is reserved for use in partition switching */ 258 kvmppc_claim_lpid(rsvd_lpid); 259 260 return 0; 261 } 262 263 void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu) 264 { 265 } 266 267 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu) 268 { 269 kvmppc_set_msr(vcpu, MSR_SF | MSR_ME); 270 } 271 272 /* 273 * This is called to get a reference to a guest page if there isn't 274 * one already in the memslot->arch.slot_phys[] array. 275 */ 276 static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn, 277 struct kvm_memory_slot *memslot, 278 unsigned long psize) 279 { 280 unsigned long start; 281 long np, err; 282 struct page *page, *hpage, *pages[1]; 283 unsigned long s, pgsize; 284 unsigned long *physp; 285 unsigned int is_io, got, pgorder; 286 struct vm_area_struct *vma; 287 unsigned long pfn, i, npages; 288 289 physp = memslot->arch.slot_phys; 290 if (!physp) 291 return -EINVAL; 292 if (physp[gfn - memslot->base_gfn]) 293 return 0; 294 295 is_io = 0; 296 got = 0; 297 page = NULL; 298 pgsize = psize; 299 err = -EINVAL; 300 start = gfn_to_hva_memslot(memslot, gfn); 301 302 /* Instantiate and get the page we want access to */ 303 np = get_user_pages_fast(start, 1, 1, pages); 304 if (np != 1) { 305 /* Look up the vma for the page */ 306 down_read(¤t->mm->mmap_sem); 307 vma = find_vma(current->mm, start); 308 if (!vma || vma->vm_start > start || 309 start + psize > vma->vm_end || 310 !(vma->vm_flags & VM_PFNMAP)) 311 goto up_err; 312 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot)); 313 pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); 314 /* check alignment of pfn vs. requested page size */ 315 if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1))) 316 goto up_err; 317 up_read(¤t->mm->mmap_sem); 318 319 } else { 320 page = pages[0]; 321 got = KVMPPC_GOT_PAGE; 322 323 /* See if this is a large page */ 324 s = PAGE_SIZE; 325 if (PageHuge(page)) { 326 hpage = compound_head(page); 327 s <<= compound_order(hpage); 328 /* Get the whole large page if slot alignment is ok */ 329 if (s > psize && slot_is_aligned(memslot, s) && 330 !(memslot->userspace_addr & (s - 1))) { 331 start &= ~(s - 1); 332 pgsize = s; 333 get_page(hpage); 334 put_page(page); 335 page = hpage; 336 } 337 } 338 if (s < psize) 339 goto out; 340 pfn = page_to_pfn(page); 341 } 342 343 npages = pgsize >> PAGE_SHIFT; 344 pgorder = __ilog2(npages); 345 physp += (gfn - memslot->base_gfn) & ~(npages - 1); 346 spin_lock(&kvm->arch.slot_phys_lock); 347 for (i = 0; i < npages; ++i) { 348 if (!physp[i]) { 349 physp[i] = ((pfn + i) << PAGE_SHIFT) + 350 got + is_io + pgorder; 351 got = 0; 352 } 353 } 354 spin_unlock(&kvm->arch.slot_phys_lock); 355 err = 0; 356 357 out: 358 if (got) 359 put_page(page); 360 return err; 361 362 up_err: 363 up_read(¤t->mm->mmap_sem); 364 return err; 365 } 366 367 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 368 long pte_index, unsigned long pteh, 369 unsigned long ptel, unsigned long *pte_idx_ret) 370 { 371 unsigned long psize, gpa, gfn; 372 struct kvm_memory_slot *memslot; 373 long ret; 374 375 if (kvm->arch.using_mmu_notifiers) 376 goto do_insert; 377 378 psize = hpte_page_size(pteh, ptel); 379 if (!psize) 380 return H_PARAMETER; 381 382 pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID); 383 384 /* Find the memslot (if any) for this address */ 385 gpa = (ptel & HPTE_R_RPN) & ~(psize - 1); 386 gfn = gpa >> PAGE_SHIFT; 387 memslot = gfn_to_memslot(kvm, gfn); 388 if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) { 389 if (!slot_is_aligned(memslot, psize)) 390 return H_PARAMETER; 391 if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0) 392 return H_PARAMETER; 393 } 394 395 do_insert: 396 /* Protect linux PTE lookup from page table destruction */ 397 rcu_read_lock_sched(); /* this disables preemption too */ 398 ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel, 399 current->mm->pgd, false, pte_idx_ret); 400 rcu_read_unlock_sched(); 401 if (ret == H_TOO_HARD) { 402 /* this can't happen */ 403 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n"); 404 ret = H_RESOURCE; /* or something */ 405 } 406 return ret; 407 408 } 409 410 /* 411 * We come here on a H_ENTER call from the guest when we are not 412 * using mmu notifiers and we don't have the requested page pinned 413 * already. 414 */ 415 long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, 416 long pte_index, unsigned long pteh, 417 unsigned long ptel) 418 { 419 return kvmppc_virtmode_do_h_enter(vcpu->kvm, flags, pte_index, 420 pteh, ptel, &vcpu->arch.gpr[4]); 421 } 422 423 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu, 424 gva_t eaddr) 425 { 426 u64 mask; 427 int i; 428 429 for (i = 0; i < vcpu->arch.slb_nr; i++) { 430 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V)) 431 continue; 432 433 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T) 434 mask = ESID_MASK_1T; 435 else 436 mask = ESID_MASK; 437 438 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0) 439 return &vcpu->arch.slb[i]; 440 } 441 return NULL; 442 } 443 444 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r, 445 unsigned long ea) 446 { 447 unsigned long ra_mask; 448 449 ra_mask = hpte_page_size(v, r) - 1; 450 return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask); 451 } 452 453 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, 454 struct kvmppc_pte *gpte, bool data) 455 { 456 struct kvm *kvm = vcpu->kvm; 457 struct kvmppc_slb *slbe; 458 unsigned long slb_v; 459 unsigned long pp, key; 460 unsigned long v, gr; 461 unsigned long *hptep; 462 int index; 463 int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR); 464 465 /* Get SLB entry */ 466 if (virtmode) { 467 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr); 468 if (!slbe) 469 return -EINVAL; 470 slb_v = slbe->origv; 471 } else { 472 /* real mode access */ 473 slb_v = vcpu->kvm->arch.vrma_slb_v; 474 } 475 476 /* Find the HPTE in the hash table */ 477 index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, 478 HPTE_V_VALID | HPTE_V_ABSENT); 479 if (index < 0) 480 return -ENOENT; 481 hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); 482 v = hptep[0] & ~HPTE_V_HVLOCK; 483 gr = kvm->arch.revmap[index].guest_rpte; 484 485 /* Unlock the HPTE */ 486 asm volatile("lwsync" : : : "memory"); 487 hptep[0] = v; 488 489 gpte->eaddr = eaddr; 490 gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff); 491 492 /* Get PP bits and key for permission check */ 493 pp = gr & (HPTE_R_PP0 | HPTE_R_PP); 494 key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS; 495 key &= slb_v; 496 497 /* Calculate permissions */ 498 gpte->may_read = hpte_read_permission(pp, key); 499 gpte->may_write = hpte_write_permission(pp, key); 500 gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G)); 501 502 /* Storage key permission check for POWER7 */ 503 if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) { 504 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr); 505 if (amrfield & 1) 506 gpte->may_read = 0; 507 if (amrfield & 2) 508 gpte->may_write = 0; 509 } 510 511 /* Get the guest physical address */ 512 gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr); 513 return 0; 514 } 515 516 /* 517 * Quick test for whether an instruction is a load or a store. 518 * If the instruction is a load or a store, then this will indicate 519 * which it is, at least on server processors. (Embedded processors 520 * have some external PID instructions that don't follow the rule 521 * embodied here.) If the instruction isn't a load or store, then 522 * this doesn't return anything useful. 523 */ 524 static int instruction_is_store(unsigned int instr) 525 { 526 unsigned int mask; 527 528 mask = 0x10000000; 529 if ((instr & 0xfc000000) == 0x7c000000) 530 mask = 0x100; /* major opcode 31 */ 531 return (instr & mask) != 0; 532 } 533 534 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, 535 unsigned long gpa, gva_t ea, int is_store) 536 { 537 int ret; 538 u32 last_inst; 539 unsigned long srr0 = kvmppc_get_pc(vcpu); 540 541 /* We try to load the last instruction. We don't let 542 * emulate_instruction do it as it doesn't check what 543 * kvmppc_ld returns. 544 * If we fail, we just return to the guest and try executing it again. 545 */ 546 if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) { 547 ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false); 548 if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED) 549 return RESUME_GUEST; 550 vcpu->arch.last_inst = last_inst; 551 } 552 553 /* 554 * WARNING: We do not know for sure whether the instruction we just 555 * read from memory is the same that caused the fault in the first 556 * place. If the instruction we read is neither an load or a store, 557 * then it can't access memory, so we don't need to worry about 558 * enforcing access permissions. So, assuming it is a load or 559 * store, we just check that its direction (load or store) is 560 * consistent with the original fault, since that's what we 561 * checked the access permissions against. If there is a mismatch 562 * we just return and retry the instruction. 563 */ 564 565 if (instruction_is_store(vcpu->arch.last_inst) != !!is_store) 566 return RESUME_GUEST; 567 568 /* 569 * Emulated accesses are emulated by looking at the hash for 570 * translation once, then performing the access later. The 571 * translation could be invalidated in the meantime in which 572 * point performing the subsequent memory access on the old 573 * physical address could possibly be a security hole for the 574 * guest (but not the host). 575 * 576 * This is less of an issue for MMIO stores since they aren't 577 * globally visible. It could be an issue for MMIO loads to 578 * a certain extent but we'll ignore it for now. 579 */ 580 581 vcpu->arch.paddr_accessed = gpa; 582 vcpu->arch.vaddr_accessed = ea; 583 return kvmppc_emulate_mmio(run, vcpu); 584 } 585 586 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 587 unsigned long ea, unsigned long dsisr) 588 { 589 struct kvm *kvm = vcpu->kvm; 590 unsigned long *hptep, hpte[3], r; 591 unsigned long mmu_seq, psize, pte_size; 592 unsigned long gpa, gfn, hva, pfn; 593 struct kvm_memory_slot *memslot; 594 unsigned long *rmap; 595 struct revmap_entry *rev; 596 struct page *page, *pages[1]; 597 long index, ret, npages; 598 unsigned long is_io; 599 unsigned int writing, write_ok; 600 struct vm_area_struct *vma; 601 unsigned long rcbits; 602 603 /* 604 * Real-mode code has already searched the HPT and found the 605 * entry we're interested in. Lock the entry and check that 606 * it hasn't changed. If it has, just return and re-execute the 607 * instruction. 608 */ 609 if (ea != vcpu->arch.pgfault_addr) 610 return RESUME_GUEST; 611 index = vcpu->arch.pgfault_index; 612 hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); 613 rev = &kvm->arch.revmap[index]; 614 preempt_disable(); 615 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 616 cpu_relax(); 617 hpte[0] = hptep[0] & ~HPTE_V_HVLOCK; 618 hpte[1] = hptep[1]; 619 hpte[2] = r = rev->guest_rpte; 620 asm volatile("lwsync" : : : "memory"); 621 hptep[0] = hpte[0]; 622 preempt_enable(); 623 624 if (hpte[0] != vcpu->arch.pgfault_hpte[0] || 625 hpte[1] != vcpu->arch.pgfault_hpte[1]) 626 return RESUME_GUEST; 627 628 /* Translate the logical address and get the page */ 629 psize = hpte_page_size(hpte[0], r); 630 gpa = (r & HPTE_R_RPN & ~(psize - 1)) | (ea & (psize - 1)); 631 gfn = gpa >> PAGE_SHIFT; 632 memslot = gfn_to_memslot(kvm, gfn); 633 634 /* No memslot means it's an emulated MMIO region */ 635 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 636 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, 637 dsisr & DSISR_ISSTORE); 638 639 if (!kvm->arch.using_mmu_notifiers) 640 return -EFAULT; /* should never get here */ 641 642 /* used to check for invalidations in progress */ 643 mmu_seq = kvm->mmu_notifier_seq; 644 smp_rmb(); 645 646 is_io = 0; 647 pfn = 0; 648 page = NULL; 649 pte_size = PAGE_SIZE; 650 writing = (dsisr & DSISR_ISSTORE) != 0; 651 /* If writing != 0, then the HPTE must allow writing, if we get here */ 652 write_ok = writing; 653 hva = gfn_to_hva_memslot(memslot, gfn); 654 npages = get_user_pages_fast(hva, 1, writing, pages); 655 if (npages < 1) { 656 /* Check if it's an I/O mapping */ 657 down_read(¤t->mm->mmap_sem); 658 vma = find_vma(current->mm, hva); 659 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end && 660 (vma->vm_flags & VM_PFNMAP)) { 661 pfn = vma->vm_pgoff + 662 ((hva - vma->vm_start) >> PAGE_SHIFT); 663 pte_size = psize; 664 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot)); 665 write_ok = vma->vm_flags & VM_WRITE; 666 } 667 up_read(¤t->mm->mmap_sem); 668 if (!pfn) 669 return -EFAULT; 670 } else { 671 page = pages[0]; 672 if (PageHuge(page)) { 673 page = compound_head(page); 674 pte_size <<= compound_order(page); 675 } 676 /* if the guest wants write access, see if that is OK */ 677 if (!writing && hpte_is_writable(r)) { 678 pte_t *ptep, pte; 679 680 /* 681 * We need to protect against page table destruction 682 * while looking up and updating the pte. 683 */ 684 rcu_read_lock_sched(); 685 ptep = find_linux_pte_or_hugepte(current->mm->pgd, 686 hva, NULL); 687 if (ptep && pte_present(*ptep)) { 688 pte = kvmppc_read_update_linux_pte(ptep, 1); 689 if (pte_write(pte)) 690 write_ok = 1; 691 } 692 rcu_read_unlock_sched(); 693 } 694 pfn = page_to_pfn(page); 695 } 696 697 ret = -EFAULT; 698 if (psize > pte_size) 699 goto out_put; 700 701 /* Check WIMG vs. the actual page we're accessing */ 702 if (!hpte_cache_flags_ok(r, is_io)) { 703 if (is_io) 704 return -EFAULT; 705 /* 706 * Allow guest to map emulated device memory as 707 * uncacheable, but actually make it cacheable. 708 */ 709 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M; 710 } 711 712 /* Set the HPTE to point to pfn */ 713 r = (r & ~(HPTE_R_PP0 - pte_size)) | (pfn << PAGE_SHIFT); 714 if (hpte_is_writable(r) && !write_ok) 715 r = hpte_make_readonly(r); 716 ret = RESUME_GUEST; 717 preempt_disable(); 718 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 719 cpu_relax(); 720 if ((hptep[0] & ~HPTE_V_HVLOCK) != hpte[0] || hptep[1] != hpte[1] || 721 rev->guest_rpte != hpte[2]) 722 /* HPTE has been changed under us; let the guest retry */ 723 goto out_unlock; 724 hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 725 726 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 727 lock_rmap(rmap); 728 729 /* Check if we might have been invalidated; let the guest retry if so */ 730 ret = RESUME_GUEST; 731 if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) { 732 unlock_rmap(rmap); 733 goto out_unlock; 734 } 735 736 /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */ 737 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT; 738 r &= rcbits | ~(HPTE_R_R | HPTE_R_C); 739 740 if (hptep[0] & HPTE_V_VALID) { 741 /* HPTE was previously valid, so we need to invalidate it */ 742 unlock_rmap(rmap); 743 hptep[0] |= HPTE_V_ABSENT; 744 kvmppc_invalidate_hpte(kvm, hptep, index); 745 /* don't lose previous R and C bits */ 746 r |= hptep[1] & (HPTE_R_R | HPTE_R_C); 747 } else { 748 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0); 749 } 750 751 hptep[1] = r; 752 eieio(); 753 hptep[0] = hpte[0]; 754 asm volatile("ptesync" : : : "memory"); 755 preempt_enable(); 756 if (page && hpte_is_writable(r)) 757 SetPageDirty(page); 758 759 out_put: 760 if (page) { 761 /* 762 * We drop pages[0] here, not page because page might 763 * have been set to the head page of a compound, but 764 * we have to drop the reference on the correct tail 765 * page to match the get inside gup() 766 */ 767 put_page(pages[0]); 768 } 769 return ret; 770 771 out_unlock: 772 hptep[0] &= ~HPTE_V_HVLOCK; 773 preempt_enable(); 774 goto out_put; 775 } 776 777 static void kvmppc_rmap_reset(struct kvm *kvm) 778 { 779 struct kvm_memslots *slots; 780 struct kvm_memory_slot *memslot; 781 int srcu_idx; 782 783 srcu_idx = srcu_read_lock(&kvm->srcu); 784 slots = kvm->memslots; 785 kvm_for_each_memslot(memslot, slots) { 786 /* 787 * This assumes it is acceptable to lose reference and 788 * change bits across a reset. 789 */ 790 memset(memslot->arch.rmap, 0, 791 memslot->npages * sizeof(*memslot->arch.rmap)); 792 } 793 srcu_read_unlock(&kvm->srcu, srcu_idx); 794 } 795 796 static int kvm_handle_hva_range(struct kvm *kvm, 797 unsigned long start, 798 unsigned long end, 799 int (*handler)(struct kvm *kvm, 800 unsigned long *rmapp, 801 unsigned long gfn)) 802 { 803 int ret; 804 int retval = 0; 805 struct kvm_memslots *slots; 806 struct kvm_memory_slot *memslot; 807 808 slots = kvm_memslots(kvm); 809 kvm_for_each_memslot(memslot, slots) { 810 unsigned long hva_start, hva_end; 811 gfn_t gfn, gfn_end; 812 813 hva_start = max(start, memslot->userspace_addr); 814 hva_end = min(end, memslot->userspace_addr + 815 (memslot->npages << PAGE_SHIFT)); 816 if (hva_start >= hva_end) 817 continue; 818 /* 819 * {gfn(page) | page intersects with [hva_start, hva_end)} = 820 * {gfn, gfn+1, ..., gfn_end-1}. 821 */ 822 gfn = hva_to_gfn_memslot(hva_start, memslot); 823 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); 824 825 for (; gfn < gfn_end; ++gfn) { 826 gfn_t gfn_offset = gfn - memslot->base_gfn; 827 828 ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn); 829 retval |= ret; 830 } 831 } 832 833 return retval; 834 } 835 836 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, 837 int (*handler)(struct kvm *kvm, unsigned long *rmapp, 838 unsigned long gfn)) 839 { 840 return kvm_handle_hva_range(kvm, hva, hva + 1, handler); 841 } 842 843 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, 844 unsigned long gfn) 845 { 846 struct revmap_entry *rev = kvm->arch.revmap; 847 unsigned long h, i, j; 848 unsigned long *hptep; 849 unsigned long ptel, psize, rcbits; 850 851 for (;;) { 852 lock_rmap(rmapp); 853 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 854 unlock_rmap(rmapp); 855 break; 856 } 857 858 /* 859 * To avoid an ABBA deadlock with the HPTE lock bit, 860 * we can't spin on the HPTE lock while holding the 861 * rmap chain lock. 862 */ 863 i = *rmapp & KVMPPC_RMAP_INDEX; 864 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 865 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 866 /* unlock rmap before spinning on the HPTE lock */ 867 unlock_rmap(rmapp); 868 while (hptep[0] & HPTE_V_HVLOCK) 869 cpu_relax(); 870 continue; 871 } 872 j = rev[i].forw; 873 if (j == i) { 874 /* chain is now empty */ 875 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX); 876 } else { 877 /* remove i from chain */ 878 h = rev[i].back; 879 rev[h].forw = j; 880 rev[j].back = h; 881 rev[i].forw = rev[i].back = i; 882 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j; 883 } 884 885 /* Now check and modify the HPTE */ 886 ptel = rev[i].guest_rpte; 887 psize = hpte_page_size(hptep[0], ptel); 888 if ((hptep[0] & HPTE_V_VALID) && 889 hpte_rpn(ptel, psize) == gfn) { 890 if (kvm->arch.using_mmu_notifiers) 891 hptep[0] |= HPTE_V_ABSENT; 892 kvmppc_invalidate_hpte(kvm, hptep, i); 893 /* Harvest R and C */ 894 rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C); 895 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT; 896 if (rcbits & ~rev[i].guest_rpte) { 897 rev[i].guest_rpte = ptel | rcbits; 898 note_hpte_modification(kvm, &rev[i]); 899 } 900 } 901 unlock_rmap(rmapp); 902 hptep[0] &= ~HPTE_V_HVLOCK; 903 } 904 return 0; 905 } 906 907 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) 908 { 909 if (kvm->arch.using_mmu_notifiers) 910 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 911 return 0; 912 } 913 914 int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end) 915 { 916 if (kvm->arch.using_mmu_notifiers) 917 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp); 918 return 0; 919 } 920 921 void kvmppc_core_flush_memslot(struct kvm *kvm, struct kvm_memory_slot *memslot) 922 { 923 unsigned long *rmapp; 924 unsigned long gfn; 925 unsigned long n; 926 927 rmapp = memslot->arch.rmap; 928 gfn = memslot->base_gfn; 929 for (n = memslot->npages; n; --n) { 930 /* 931 * Testing the present bit without locking is OK because 932 * the memslot has been marked invalid already, and hence 933 * no new HPTEs referencing this page can be created, 934 * thus the present bit can't go from 0 to 1. 935 */ 936 if (*rmapp & KVMPPC_RMAP_PRESENT) 937 kvm_unmap_rmapp(kvm, rmapp, gfn); 938 ++rmapp; 939 ++gfn; 940 } 941 } 942 943 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 944 unsigned long gfn) 945 { 946 struct revmap_entry *rev = kvm->arch.revmap; 947 unsigned long head, i, j; 948 unsigned long *hptep; 949 int ret = 0; 950 951 retry: 952 lock_rmap(rmapp); 953 if (*rmapp & KVMPPC_RMAP_REFERENCED) { 954 *rmapp &= ~KVMPPC_RMAP_REFERENCED; 955 ret = 1; 956 } 957 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 958 unlock_rmap(rmapp); 959 return ret; 960 } 961 962 i = head = *rmapp & KVMPPC_RMAP_INDEX; 963 do { 964 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 965 j = rev[i].forw; 966 967 /* If this HPTE isn't referenced, ignore it */ 968 if (!(hptep[1] & HPTE_R_R)) 969 continue; 970 971 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 972 /* unlock rmap before spinning on the HPTE lock */ 973 unlock_rmap(rmapp); 974 while (hptep[0] & HPTE_V_HVLOCK) 975 cpu_relax(); 976 goto retry; 977 } 978 979 /* Now check and modify the HPTE */ 980 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) { 981 kvmppc_clear_ref_hpte(kvm, hptep, i); 982 if (!(rev[i].guest_rpte & HPTE_R_R)) { 983 rev[i].guest_rpte |= HPTE_R_R; 984 note_hpte_modification(kvm, &rev[i]); 985 } 986 ret = 1; 987 } 988 hptep[0] &= ~HPTE_V_HVLOCK; 989 } while ((i = j) != head); 990 991 unlock_rmap(rmapp); 992 return ret; 993 } 994 995 int kvm_age_hva(struct kvm *kvm, unsigned long hva) 996 { 997 if (!kvm->arch.using_mmu_notifiers) 998 return 0; 999 return kvm_handle_hva(kvm, hva, kvm_age_rmapp); 1000 } 1001 1002 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 1003 unsigned long gfn) 1004 { 1005 struct revmap_entry *rev = kvm->arch.revmap; 1006 unsigned long head, i, j; 1007 unsigned long *hp; 1008 int ret = 1; 1009 1010 if (*rmapp & KVMPPC_RMAP_REFERENCED) 1011 return 1; 1012 1013 lock_rmap(rmapp); 1014 if (*rmapp & KVMPPC_RMAP_REFERENCED) 1015 goto out; 1016 1017 if (*rmapp & KVMPPC_RMAP_PRESENT) { 1018 i = head = *rmapp & KVMPPC_RMAP_INDEX; 1019 do { 1020 hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4)); 1021 j = rev[i].forw; 1022 if (hp[1] & HPTE_R_R) 1023 goto out; 1024 } while ((i = j) != head); 1025 } 1026 ret = 0; 1027 1028 out: 1029 unlock_rmap(rmapp); 1030 return ret; 1031 } 1032 1033 int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) 1034 { 1035 if (!kvm->arch.using_mmu_notifiers) 1036 return 0; 1037 return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp); 1038 } 1039 1040 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) 1041 { 1042 if (!kvm->arch.using_mmu_notifiers) 1043 return; 1044 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 1045 } 1046 1047 static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) 1048 { 1049 struct revmap_entry *rev = kvm->arch.revmap; 1050 unsigned long head, i, j; 1051 unsigned long *hptep; 1052 int ret = 0; 1053 1054 retry: 1055 lock_rmap(rmapp); 1056 if (*rmapp & KVMPPC_RMAP_CHANGED) { 1057 *rmapp &= ~KVMPPC_RMAP_CHANGED; 1058 ret = 1; 1059 } 1060 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 1061 unlock_rmap(rmapp); 1062 return ret; 1063 } 1064 1065 i = head = *rmapp & KVMPPC_RMAP_INDEX; 1066 do { 1067 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 1068 j = rev[i].forw; 1069 1070 if (!(hptep[1] & HPTE_R_C)) 1071 continue; 1072 1073 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 1074 /* unlock rmap before spinning on the HPTE lock */ 1075 unlock_rmap(rmapp); 1076 while (hptep[0] & HPTE_V_HVLOCK) 1077 cpu_relax(); 1078 goto retry; 1079 } 1080 1081 /* Now check and modify the HPTE */ 1082 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) { 1083 /* need to make it temporarily absent to clear C */ 1084 hptep[0] |= HPTE_V_ABSENT; 1085 kvmppc_invalidate_hpte(kvm, hptep, i); 1086 hptep[1] &= ~HPTE_R_C; 1087 eieio(); 1088 hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 1089 if (!(rev[i].guest_rpte & HPTE_R_C)) { 1090 rev[i].guest_rpte |= HPTE_R_C; 1091 note_hpte_modification(kvm, &rev[i]); 1092 } 1093 ret = 1; 1094 } 1095 hptep[0] &= ~HPTE_V_HVLOCK; 1096 } while ((i = j) != head); 1097 1098 unlock_rmap(rmapp); 1099 return ret; 1100 } 1101 1102 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, 1103 struct kvm_memory_slot *memslot, 1104 unsigned long *map) 1105 { 1106 unsigned long gfn; 1107 1108 if (!vpa->dirty || !vpa->pinned_addr) 1109 return; 1110 gfn = vpa->gpa >> PAGE_SHIFT; 1111 if (gfn < memslot->base_gfn || 1112 gfn >= memslot->base_gfn + memslot->npages) 1113 return; 1114 1115 vpa->dirty = false; 1116 if (map) 1117 __set_bit_le(gfn - memslot->base_gfn, map); 1118 } 1119 1120 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, 1121 unsigned long *map) 1122 { 1123 unsigned long i; 1124 unsigned long *rmapp; 1125 struct kvm_vcpu *vcpu; 1126 1127 preempt_disable(); 1128 rmapp = memslot->arch.rmap; 1129 for (i = 0; i < memslot->npages; ++i) { 1130 if (kvm_test_clear_dirty(kvm, rmapp) && map) 1131 __set_bit_le(i, map); 1132 ++rmapp; 1133 } 1134 1135 /* Harvest dirty bits from VPA and DTL updates */ 1136 /* Note: we never modify the SLB shadow buffer areas */ 1137 kvm_for_each_vcpu(i, vcpu, kvm) { 1138 spin_lock(&vcpu->arch.vpa_update_lock); 1139 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map); 1140 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map); 1141 spin_unlock(&vcpu->arch.vpa_update_lock); 1142 } 1143 preempt_enable(); 1144 return 0; 1145 } 1146 1147 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, 1148 unsigned long *nb_ret) 1149 { 1150 struct kvm_memory_slot *memslot; 1151 unsigned long gfn = gpa >> PAGE_SHIFT; 1152 struct page *page, *pages[1]; 1153 int npages; 1154 unsigned long hva, offset; 1155 unsigned long pa; 1156 unsigned long *physp; 1157 int srcu_idx; 1158 1159 srcu_idx = srcu_read_lock(&kvm->srcu); 1160 memslot = gfn_to_memslot(kvm, gfn); 1161 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 1162 goto err; 1163 if (!kvm->arch.using_mmu_notifiers) { 1164 physp = memslot->arch.slot_phys; 1165 if (!physp) 1166 goto err; 1167 physp += gfn - memslot->base_gfn; 1168 pa = *physp; 1169 if (!pa) { 1170 if (kvmppc_get_guest_page(kvm, gfn, memslot, 1171 PAGE_SIZE) < 0) 1172 goto err; 1173 pa = *physp; 1174 } 1175 page = pfn_to_page(pa >> PAGE_SHIFT); 1176 get_page(page); 1177 } else { 1178 hva = gfn_to_hva_memslot(memslot, gfn); 1179 npages = get_user_pages_fast(hva, 1, 1, pages); 1180 if (npages < 1) 1181 goto err; 1182 page = pages[0]; 1183 } 1184 srcu_read_unlock(&kvm->srcu, srcu_idx); 1185 1186 offset = gpa & (PAGE_SIZE - 1); 1187 if (nb_ret) 1188 *nb_ret = PAGE_SIZE - offset; 1189 return page_address(page) + offset; 1190 1191 err: 1192 srcu_read_unlock(&kvm->srcu, srcu_idx); 1193 return NULL; 1194 } 1195 1196 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa, 1197 bool dirty) 1198 { 1199 struct page *page = virt_to_page(va); 1200 struct kvm_memory_slot *memslot; 1201 unsigned long gfn; 1202 unsigned long *rmap; 1203 int srcu_idx; 1204 1205 put_page(page); 1206 1207 if (!dirty || !kvm->arch.using_mmu_notifiers) 1208 return; 1209 1210 /* We need to mark this page dirty in the rmap chain */ 1211 gfn = gpa >> PAGE_SHIFT; 1212 srcu_idx = srcu_read_lock(&kvm->srcu); 1213 memslot = gfn_to_memslot(kvm, gfn); 1214 if (memslot) { 1215 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 1216 lock_rmap(rmap); 1217 *rmap |= KVMPPC_RMAP_CHANGED; 1218 unlock_rmap(rmap); 1219 } 1220 srcu_read_unlock(&kvm->srcu, srcu_idx); 1221 } 1222 1223 /* 1224 * Functions for reading and writing the hash table via reads and 1225 * writes on a file descriptor. 1226 * 1227 * Reads return the guest view of the hash table, which has to be 1228 * pieced together from the real hash table and the guest_rpte 1229 * values in the revmap array. 1230 * 1231 * On writes, each HPTE written is considered in turn, and if it 1232 * is valid, it is written to the HPT as if an H_ENTER with the 1233 * exact flag set was done. When the invalid count is non-zero 1234 * in the header written to the stream, the kernel will make 1235 * sure that that many HPTEs are invalid, and invalidate them 1236 * if not. 1237 */ 1238 1239 struct kvm_htab_ctx { 1240 unsigned long index; 1241 unsigned long flags; 1242 struct kvm *kvm; 1243 int first_pass; 1244 }; 1245 1246 #define HPTE_SIZE (2 * sizeof(unsigned long)) 1247 1248 /* 1249 * Returns 1 if this HPT entry has been modified or has pending 1250 * R/C bit changes. 1251 */ 1252 static int hpte_dirty(struct revmap_entry *revp, unsigned long *hptp) 1253 { 1254 unsigned long rcbits_unset; 1255 1256 if (revp->guest_rpte & HPTE_GR_MODIFIED) 1257 return 1; 1258 1259 /* Also need to consider changes in reference and changed bits */ 1260 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1261 if ((hptp[0] & HPTE_V_VALID) && (hptp[1] & rcbits_unset)) 1262 return 1; 1263 1264 return 0; 1265 } 1266 1267 static long record_hpte(unsigned long flags, unsigned long *hptp, 1268 unsigned long *hpte, struct revmap_entry *revp, 1269 int want_valid, int first_pass) 1270 { 1271 unsigned long v, r; 1272 unsigned long rcbits_unset; 1273 int ok = 1; 1274 int valid, dirty; 1275 1276 /* Unmodified entries are uninteresting except on the first pass */ 1277 dirty = hpte_dirty(revp, hptp); 1278 if (!first_pass && !dirty) 1279 return 0; 1280 1281 valid = 0; 1282 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) { 1283 valid = 1; 1284 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && 1285 !(hptp[0] & HPTE_V_BOLTED)) 1286 valid = 0; 1287 } 1288 if (valid != want_valid) 1289 return 0; 1290 1291 v = r = 0; 1292 if (valid || dirty) { 1293 /* lock the HPTE so it's stable and read it */ 1294 preempt_disable(); 1295 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) 1296 cpu_relax(); 1297 v = hptp[0]; 1298 1299 /* re-evaluate valid and dirty from synchronized HPTE value */ 1300 valid = !!(v & HPTE_V_VALID); 1301 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); 1302 1303 /* Harvest R and C into guest view if necessary */ 1304 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1305 if (valid && (rcbits_unset & hptp[1])) { 1306 revp->guest_rpte |= (hptp[1] & (HPTE_R_R | HPTE_R_C)) | 1307 HPTE_GR_MODIFIED; 1308 dirty = 1; 1309 } 1310 1311 if (v & HPTE_V_ABSENT) { 1312 v &= ~HPTE_V_ABSENT; 1313 v |= HPTE_V_VALID; 1314 valid = 1; 1315 } 1316 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) 1317 valid = 0; 1318 1319 r = revp->guest_rpte; 1320 /* only clear modified if this is the right sort of entry */ 1321 if (valid == want_valid && dirty) { 1322 r &= ~HPTE_GR_MODIFIED; 1323 revp->guest_rpte = r; 1324 } 1325 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory"); 1326 hptp[0] &= ~HPTE_V_HVLOCK; 1327 preempt_enable(); 1328 if (!(valid == want_valid && (first_pass || dirty))) 1329 ok = 0; 1330 } 1331 hpte[0] = v; 1332 hpte[1] = r; 1333 return ok; 1334 } 1335 1336 static ssize_t kvm_htab_read(struct file *file, char __user *buf, 1337 size_t count, loff_t *ppos) 1338 { 1339 struct kvm_htab_ctx *ctx = file->private_data; 1340 struct kvm *kvm = ctx->kvm; 1341 struct kvm_get_htab_header hdr; 1342 unsigned long *hptp; 1343 struct revmap_entry *revp; 1344 unsigned long i, nb, nw; 1345 unsigned long __user *lbuf; 1346 struct kvm_get_htab_header __user *hptr; 1347 unsigned long flags; 1348 int first_pass; 1349 unsigned long hpte[2]; 1350 1351 if (!access_ok(VERIFY_WRITE, buf, count)) 1352 return -EFAULT; 1353 1354 first_pass = ctx->first_pass; 1355 flags = ctx->flags; 1356 1357 i = ctx->index; 1358 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1359 revp = kvm->arch.revmap + i; 1360 lbuf = (unsigned long __user *)buf; 1361 1362 nb = 0; 1363 while (nb + sizeof(hdr) + HPTE_SIZE < count) { 1364 /* Initialize header */ 1365 hptr = (struct kvm_get_htab_header __user *)buf; 1366 hdr.n_valid = 0; 1367 hdr.n_invalid = 0; 1368 nw = nb; 1369 nb += sizeof(hdr); 1370 lbuf = (unsigned long __user *)(buf + sizeof(hdr)); 1371 1372 /* Skip uninteresting entries, i.e. clean on not-first pass */ 1373 if (!first_pass) { 1374 while (i < kvm->arch.hpt_npte && 1375 !hpte_dirty(revp, hptp)) { 1376 ++i; 1377 hptp += 2; 1378 ++revp; 1379 } 1380 } 1381 hdr.index = i; 1382 1383 /* Grab a series of valid entries */ 1384 while (i < kvm->arch.hpt_npte && 1385 hdr.n_valid < 0xffff && 1386 nb + HPTE_SIZE < count && 1387 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) { 1388 /* valid entry, write it out */ 1389 ++hdr.n_valid; 1390 if (__put_user(hpte[0], lbuf) || 1391 __put_user(hpte[1], lbuf + 1)) 1392 return -EFAULT; 1393 nb += HPTE_SIZE; 1394 lbuf += 2; 1395 ++i; 1396 hptp += 2; 1397 ++revp; 1398 } 1399 /* Now skip invalid entries while we can */ 1400 while (i < kvm->arch.hpt_npte && 1401 hdr.n_invalid < 0xffff && 1402 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) { 1403 /* found an invalid entry */ 1404 ++hdr.n_invalid; 1405 ++i; 1406 hptp += 2; 1407 ++revp; 1408 } 1409 1410 if (hdr.n_valid || hdr.n_invalid) { 1411 /* write back the header */ 1412 if (__copy_to_user(hptr, &hdr, sizeof(hdr))) 1413 return -EFAULT; 1414 nw = nb; 1415 buf = (char __user *)lbuf; 1416 } else { 1417 nb = nw; 1418 } 1419 1420 /* Check if we've wrapped around the hash table */ 1421 if (i >= kvm->arch.hpt_npte) { 1422 i = 0; 1423 ctx->first_pass = 0; 1424 break; 1425 } 1426 } 1427 1428 ctx->index = i; 1429 1430 return nb; 1431 } 1432 1433 static ssize_t kvm_htab_write(struct file *file, const char __user *buf, 1434 size_t count, loff_t *ppos) 1435 { 1436 struct kvm_htab_ctx *ctx = file->private_data; 1437 struct kvm *kvm = ctx->kvm; 1438 struct kvm_get_htab_header hdr; 1439 unsigned long i, j; 1440 unsigned long v, r; 1441 unsigned long __user *lbuf; 1442 unsigned long *hptp; 1443 unsigned long tmp[2]; 1444 ssize_t nb; 1445 long int err, ret; 1446 int rma_setup; 1447 1448 if (!access_ok(VERIFY_READ, buf, count)) 1449 return -EFAULT; 1450 1451 /* lock out vcpus from running while we're doing this */ 1452 mutex_lock(&kvm->lock); 1453 rma_setup = kvm->arch.rma_setup_done; 1454 if (rma_setup) { 1455 kvm->arch.rma_setup_done = 0; /* temporarily */ 1456 /* order rma_setup_done vs. vcpus_running */ 1457 smp_mb(); 1458 if (atomic_read(&kvm->arch.vcpus_running)) { 1459 kvm->arch.rma_setup_done = 1; 1460 mutex_unlock(&kvm->lock); 1461 return -EBUSY; 1462 } 1463 } 1464 1465 err = 0; 1466 for (nb = 0; nb + sizeof(hdr) <= count; ) { 1467 err = -EFAULT; 1468 if (__copy_from_user(&hdr, buf, sizeof(hdr))) 1469 break; 1470 1471 err = 0; 1472 if (nb + hdr.n_valid * HPTE_SIZE > count) 1473 break; 1474 1475 nb += sizeof(hdr); 1476 buf += sizeof(hdr); 1477 1478 err = -EINVAL; 1479 i = hdr.index; 1480 if (i >= kvm->arch.hpt_npte || 1481 i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte) 1482 break; 1483 1484 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1485 lbuf = (unsigned long __user *)buf; 1486 for (j = 0; j < hdr.n_valid; ++j) { 1487 err = -EFAULT; 1488 if (__get_user(v, lbuf) || __get_user(r, lbuf + 1)) 1489 goto out; 1490 err = -EINVAL; 1491 if (!(v & HPTE_V_VALID)) 1492 goto out; 1493 lbuf += 2; 1494 nb += HPTE_SIZE; 1495 1496 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) 1497 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1498 err = -EIO; 1499 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r, 1500 tmp); 1501 if (ret != H_SUCCESS) { 1502 pr_err("kvm_htab_write ret %ld i=%ld v=%lx " 1503 "r=%lx\n", ret, i, v, r); 1504 goto out; 1505 } 1506 if (!rma_setup && is_vrma_hpte(v)) { 1507 unsigned long psize = hpte_page_size(v, r); 1508 unsigned long senc = slb_pgsize_encoding(psize); 1509 unsigned long lpcr; 1510 1511 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T | 1512 (VRMA_VSID << SLB_VSID_SHIFT_1T); 1513 lpcr = kvm->arch.lpcr & ~LPCR_VRMASD; 1514 lpcr |= senc << (LPCR_VRMASD_SH - 4); 1515 kvm->arch.lpcr = lpcr; 1516 rma_setup = 1; 1517 } 1518 ++i; 1519 hptp += 2; 1520 } 1521 1522 for (j = 0; j < hdr.n_invalid; ++j) { 1523 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) 1524 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1525 ++i; 1526 hptp += 2; 1527 } 1528 err = 0; 1529 } 1530 1531 out: 1532 /* Order HPTE updates vs. rma_setup_done */ 1533 smp_wmb(); 1534 kvm->arch.rma_setup_done = rma_setup; 1535 mutex_unlock(&kvm->lock); 1536 1537 if (err) 1538 return err; 1539 return nb; 1540 } 1541 1542 static int kvm_htab_release(struct inode *inode, struct file *filp) 1543 { 1544 struct kvm_htab_ctx *ctx = filp->private_data; 1545 1546 filp->private_data = NULL; 1547 if (!(ctx->flags & KVM_GET_HTAB_WRITE)) 1548 atomic_dec(&ctx->kvm->arch.hpte_mod_interest); 1549 kvm_put_kvm(ctx->kvm); 1550 kfree(ctx); 1551 return 0; 1552 } 1553 1554 static const struct file_operations kvm_htab_fops = { 1555 .read = kvm_htab_read, 1556 .write = kvm_htab_write, 1557 .llseek = default_llseek, 1558 .release = kvm_htab_release, 1559 }; 1560 1561 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf) 1562 { 1563 int ret; 1564 struct kvm_htab_ctx *ctx; 1565 int rwflag; 1566 1567 /* reject flags we don't recognize */ 1568 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE)) 1569 return -EINVAL; 1570 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 1571 if (!ctx) 1572 return -ENOMEM; 1573 kvm_get_kvm(kvm); 1574 ctx->kvm = kvm; 1575 ctx->index = ghf->start_index; 1576 ctx->flags = ghf->flags; 1577 ctx->first_pass = 1; 1578 1579 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY; 1580 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag); 1581 if (ret < 0) { 1582 kvm_put_kvm(kvm); 1583 return ret; 1584 } 1585 1586 if (rwflag == O_RDONLY) { 1587 mutex_lock(&kvm->slots_lock); 1588 atomic_inc(&kvm->arch.hpte_mod_interest); 1589 /* make sure kvmppc_do_h_enter etc. see the increment */ 1590 synchronize_srcu_expedited(&kvm->srcu); 1591 mutex_unlock(&kvm->slots_lock); 1592 } 1593 1594 return ret; 1595 } 1596 1597 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) 1598 { 1599 struct kvmppc_mmu *mmu = &vcpu->arch.mmu; 1600 1601 if (cpu_has_feature(CPU_FTR_ARCH_206)) 1602 vcpu->arch.slb_nr = 32; /* POWER7 */ 1603 else 1604 vcpu->arch.slb_nr = 64; 1605 1606 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate; 1607 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr; 1608 1609 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; 1610 } 1611