1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License, version 2, as 4 * published by the Free Software Foundation. 5 * 6 * This program is distributed in the hope that it will be useful, 7 * but WITHOUT ANY WARRANTY; without even the implied warranty of 8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 9 * GNU General Public License for more details. 10 * 11 * You should have received a copy of the GNU General Public License 12 * along with this program; if not, write to the Free Software 13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 14 * 15 * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> 16 */ 17 18 #include <linux/types.h> 19 #include <linux/string.h> 20 #include <linux/kvm.h> 21 #include <linux/kvm_host.h> 22 #include <linux/highmem.h> 23 #include <linux/gfp.h> 24 #include <linux/slab.h> 25 #include <linux/hugetlb.h> 26 #include <linux/vmalloc.h> 27 #include <linux/srcu.h> 28 #include <linux/anon_inodes.h> 29 #include <linux/file.h> 30 31 #include <asm/tlbflush.h> 32 #include <asm/kvm_ppc.h> 33 #include <asm/kvm_book3s.h> 34 #include <asm/mmu-hash64.h> 35 #include <asm/hvcall.h> 36 #include <asm/synch.h> 37 #include <asm/ppc-opcode.h> 38 #include <asm/cputable.h> 39 40 #include "book3s_hv_cma.h" 41 42 /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */ 43 #define MAX_LPID_970 63 44 45 /* Power architecture requires HPT is at least 256kB */ 46 #define PPC_MIN_HPT_ORDER 18 47 48 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 49 long pte_index, unsigned long pteh, 50 unsigned long ptel, unsigned long *pte_idx_ret); 51 static void kvmppc_rmap_reset(struct kvm *kvm); 52 53 long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp) 54 { 55 unsigned long hpt; 56 struct revmap_entry *rev; 57 struct page *page = NULL; 58 long order = KVM_DEFAULT_HPT_ORDER; 59 60 if (htab_orderp) { 61 order = *htab_orderp; 62 if (order < PPC_MIN_HPT_ORDER) 63 order = PPC_MIN_HPT_ORDER; 64 } 65 66 kvm->arch.hpt_cma_alloc = 0; 67 /* 68 * try first to allocate it from the kernel page allocator. 69 * We keep the CMA reserved for failed allocation. 70 */ 71 hpt = __get_free_pages(GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT | 72 __GFP_NOWARN, order - PAGE_SHIFT); 73 74 /* Next try to allocate from the preallocated pool */ 75 if (!hpt) { 76 VM_BUG_ON(order < KVM_CMA_CHUNK_ORDER); 77 page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT)); 78 if (page) { 79 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page)); 80 kvm->arch.hpt_cma_alloc = 1; 81 } else 82 --order; 83 } 84 85 /* Lastly try successively smaller sizes from the page allocator */ 86 while (!hpt && order > PPC_MIN_HPT_ORDER) { 87 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT| 88 __GFP_NOWARN, order - PAGE_SHIFT); 89 if (!hpt) 90 --order; 91 } 92 93 if (!hpt) 94 return -ENOMEM; 95 96 kvm->arch.hpt_virt = hpt; 97 kvm->arch.hpt_order = order; 98 /* HPTEs are 2**4 bytes long */ 99 kvm->arch.hpt_npte = 1ul << (order - 4); 100 /* 128 (2**7) bytes in each HPTEG */ 101 kvm->arch.hpt_mask = (1ul << (order - 7)) - 1; 102 103 /* Allocate reverse map array */ 104 rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte); 105 if (!rev) { 106 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n"); 107 goto out_freehpt; 108 } 109 kvm->arch.revmap = rev; 110 kvm->arch.sdr1 = __pa(hpt) | (order - 18); 111 112 pr_info("KVM guest htab at %lx (order %ld), LPID %x\n", 113 hpt, order, kvm->arch.lpid); 114 115 if (htab_orderp) 116 *htab_orderp = order; 117 return 0; 118 119 out_freehpt: 120 if (kvm->arch.hpt_cma_alloc) 121 kvm_release_hpt(page, 1 << (order - PAGE_SHIFT)); 122 else 123 free_pages(hpt, order - PAGE_SHIFT); 124 return -ENOMEM; 125 } 126 127 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp) 128 { 129 long err = -EBUSY; 130 long order; 131 132 mutex_lock(&kvm->lock); 133 if (kvm->arch.rma_setup_done) { 134 kvm->arch.rma_setup_done = 0; 135 /* order rma_setup_done vs. vcpus_running */ 136 smp_mb(); 137 if (atomic_read(&kvm->arch.vcpus_running)) { 138 kvm->arch.rma_setup_done = 1; 139 goto out; 140 } 141 } 142 if (kvm->arch.hpt_virt) { 143 order = kvm->arch.hpt_order; 144 /* Set the entire HPT to 0, i.e. invalid HPTEs */ 145 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order); 146 /* 147 * Reset all the reverse-mapping chains for all memslots 148 */ 149 kvmppc_rmap_reset(kvm); 150 /* Ensure that each vcpu will flush its TLB on next entry. */ 151 cpumask_setall(&kvm->arch.need_tlb_flush); 152 *htab_orderp = order; 153 err = 0; 154 } else { 155 err = kvmppc_alloc_hpt(kvm, htab_orderp); 156 order = *htab_orderp; 157 } 158 out: 159 mutex_unlock(&kvm->lock); 160 return err; 161 } 162 163 void kvmppc_free_hpt(struct kvm *kvm) 164 { 165 kvmppc_free_lpid(kvm->arch.lpid); 166 vfree(kvm->arch.revmap); 167 if (kvm->arch.hpt_cma_alloc) 168 kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt), 169 1 << (kvm->arch.hpt_order - PAGE_SHIFT)); 170 else 171 free_pages(kvm->arch.hpt_virt, 172 kvm->arch.hpt_order - PAGE_SHIFT); 173 } 174 175 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */ 176 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize) 177 { 178 return (pgsize > 0x1000) ? HPTE_V_LARGE : 0; 179 } 180 181 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */ 182 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize) 183 { 184 return (pgsize == 0x10000) ? 0x1000 : 0; 185 } 186 187 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, 188 unsigned long porder) 189 { 190 unsigned long i; 191 unsigned long npages; 192 unsigned long hp_v, hp_r; 193 unsigned long addr, hash; 194 unsigned long psize; 195 unsigned long hp0, hp1; 196 unsigned long idx_ret; 197 long ret; 198 struct kvm *kvm = vcpu->kvm; 199 200 psize = 1ul << porder; 201 npages = memslot->npages >> (porder - PAGE_SHIFT); 202 203 /* VRMA can't be > 1TB */ 204 if (npages > 1ul << (40 - porder)) 205 npages = 1ul << (40 - porder); 206 /* Can't use more than 1 HPTE per HPTEG */ 207 if (npages > kvm->arch.hpt_mask + 1) 208 npages = kvm->arch.hpt_mask + 1; 209 210 hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) | 211 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize); 212 hp1 = hpte1_pgsize_encoding(psize) | 213 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX; 214 215 for (i = 0; i < npages; ++i) { 216 addr = i << porder; 217 /* can't use hpt_hash since va > 64 bits */ 218 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask; 219 /* 220 * We assume that the hash table is empty and no 221 * vcpus are using it at this stage. Since we create 222 * at most one HPTE per HPTEG, we just assume entry 7 223 * is available and use it. 224 */ 225 hash = (hash << 3) + 7; 226 hp_v = hp0 | ((addr >> 16) & ~0x7fUL); 227 hp_r = hp1 | addr; 228 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r, 229 &idx_ret); 230 if (ret != H_SUCCESS) { 231 pr_err("KVM: map_vrma at %lx failed, ret=%ld\n", 232 addr, ret); 233 break; 234 } 235 } 236 } 237 238 int kvmppc_mmu_hv_init(void) 239 { 240 unsigned long host_lpid, rsvd_lpid; 241 242 if (!cpu_has_feature(CPU_FTR_HVMODE)) 243 return -EINVAL; 244 245 /* POWER7 has 10-bit LPIDs, PPC970 and e500mc have 6-bit LPIDs */ 246 if (cpu_has_feature(CPU_FTR_ARCH_206)) { 247 host_lpid = mfspr(SPRN_LPID); /* POWER7 */ 248 rsvd_lpid = LPID_RSVD; 249 } else { 250 host_lpid = 0; /* PPC970 */ 251 rsvd_lpid = MAX_LPID_970; 252 } 253 254 kvmppc_init_lpid(rsvd_lpid + 1); 255 256 kvmppc_claim_lpid(host_lpid); 257 /* rsvd_lpid is reserved for use in partition switching */ 258 kvmppc_claim_lpid(rsvd_lpid); 259 260 return 0; 261 } 262 263 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 unsigned int hugepage_shift; 679 pte_t *ptep, pte; 680 681 /* 682 * We need to protect against page table destruction 683 * while looking up and updating the pte. 684 */ 685 rcu_read_lock_sched(); 686 ptep = find_linux_pte_or_hugepte(current->mm->pgd, 687 hva, &hugepage_shift); 688 if (ptep) { 689 pte = kvmppc_read_update_linux_pte(ptep, 1, 690 hugepage_shift); 691 if (pte_write(pte)) 692 write_ok = 1; 693 } 694 rcu_read_unlock_sched(); 695 } 696 pfn = page_to_pfn(page); 697 } 698 699 ret = -EFAULT; 700 if (psize > pte_size) 701 goto out_put; 702 703 /* Check WIMG vs. the actual page we're accessing */ 704 if (!hpte_cache_flags_ok(r, is_io)) { 705 if (is_io) 706 return -EFAULT; 707 /* 708 * Allow guest to map emulated device memory as 709 * uncacheable, but actually make it cacheable. 710 */ 711 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M; 712 } 713 714 /* Set the HPTE to point to pfn */ 715 r = (r & ~(HPTE_R_PP0 - pte_size)) | (pfn << PAGE_SHIFT); 716 if (hpte_is_writable(r) && !write_ok) 717 r = hpte_make_readonly(r); 718 ret = RESUME_GUEST; 719 preempt_disable(); 720 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 721 cpu_relax(); 722 if ((hptep[0] & ~HPTE_V_HVLOCK) != hpte[0] || hptep[1] != hpte[1] || 723 rev->guest_rpte != hpte[2]) 724 /* HPTE has been changed under us; let the guest retry */ 725 goto out_unlock; 726 hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 727 728 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 729 lock_rmap(rmap); 730 731 /* Check if we might have been invalidated; let the guest retry if so */ 732 ret = RESUME_GUEST; 733 if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) { 734 unlock_rmap(rmap); 735 goto out_unlock; 736 } 737 738 /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */ 739 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT; 740 r &= rcbits | ~(HPTE_R_R | HPTE_R_C); 741 742 if (hptep[0] & HPTE_V_VALID) { 743 /* HPTE was previously valid, so we need to invalidate it */ 744 unlock_rmap(rmap); 745 hptep[0] |= HPTE_V_ABSENT; 746 kvmppc_invalidate_hpte(kvm, hptep, index); 747 /* don't lose previous R and C bits */ 748 r |= hptep[1] & (HPTE_R_R | HPTE_R_C); 749 } else { 750 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0); 751 } 752 753 hptep[1] = r; 754 eieio(); 755 hptep[0] = hpte[0]; 756 asm volatile("ptesync" : : : "memory"); 757 preempt_enable(); 758 if (page && hpte_is_writable(r)) 759 SetPageDirty(page); 760 761 out_put: 762 if (page) { 763 /* 764 * We drop pages[0] here, not page because page might 765 * have been set to the head page of a compound, but 766 * we have to drop the reference on the correct tail 767 * page to match the get inside gup() 768 */ 769 put_page(pages[0]); 770 } 771 return ret; 772 773 out_unlock: 774 hptep[0] &= ~HPTE_V_HVLOCK; 775 preempt_enable(); 776 goto out_put; 777 } 778 779 static void kvmppc_rmap_reset(struct kvm *kvm) 780 { 781 struct kvm_memslots *slots; 782 struct kvm_memory_slot *memslot; 783 int srcu_idx; 784 785 srcu_idx = srcu_read_lock(&kvm->srcu); 786 slots = kvm->memslots; 787 kvm_for_each_memslot(memslot, slots) { 788 /* 789 * This assumes it is acceptable to lose reference and 790 * change bits across a reset. 791 */ 792 memset(memslot->arch.rmap, 0, 793 memslot->npages * sizeof(*memslot->arch.rmap)); 794 } 795 srcu_read_unlock(&kvm->srcu, srcu_idx); 796 } 797 798 static int kvm_handle_hva_range(struct kvm *kvm, 799 unsigned long start, 800 unsigned long end, 801 int (*handler)(struct kvm *kvm, 802 unsigned long *rmapp, 803 unsigned long gfn)) 804 { 805 int ret; 806 int retval = 0; 807 struct kvm_memslots *slots; 808 struct kvm_memory_slot *memslot; 809 810 slots = kvm_memslots(kvm); 811 kvm_for_each_memslot(memslot, slots) { 812 unsigned long hva_start, hva_end; 813 gfn_t gfn, gfn_end; 814 815 hva_start = max(start, memslot->userspace_addr); 816 hva_end = min(end, memslot->userspace_addr + 817 (memslot->npages << PAGE_SHIFT)); 818 if (hva_start >= hva_end) 819 continue; 820 /* 821 * {gfn(page) | page intersects with [hva_start, hva_end)} = 822 * {gfn, gfn+1, ..., gfn_end-1}. 823 */ 824 gfn = hva_to_gfn_memslot(hva_start, memslot); 825 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); 826 827 for (; gfn < gfn_end; ++gfn) { 828 gfn_t gfn_offset = gfn - memslot->base_gfn; 829 830 ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn); 831 retval |= ret; 832 } 833 } 834 835 return retval; 836 } 837 838 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, 839 int (*handler)(struct kvm *kvm, unsigned long *rmapp, 840 unsigned long gfn)) 841 { 842 return kvm_handle_hva_range(kvm, hva, hva + 1, handler); 843 } 844 845 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, 846 unsigned long gfn) 847 { 848 struct revmap_entry *rev = kvm->arch.revmap; 849 unsigned long h, i, j; 850 unsigned long *hptep; 851 unsigned long ptel, psize, rcbits; 852 853 for (;;) { 854 lock_rmap(rmapp); 855 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 856 unlock_rmap(rmapp); 857 break; 858 } 859 860 /* 861 * To avoid an ABBA deadlock with the HPTE lock bit, 862 * we can't spin on the HPTE lock while holding the 863 * rmap chain lock. 864 */ 865 i = *rmapp & KVMPPC_RMAP_INDEX; 866 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 867 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 868 /* unlock rmap before spinning on the HPTE lock */ 869 unlock_rmap(rmapp); 870 while (hptep[0] & HPTE_V_HVLOCK) 871 cpu_relax(); 872 continue; 873 } 874 j = rev[i].forw; 875 if (j == i) { 876 /* chain is now empty */ 877 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX); 878 } else { 879 /* remove i from chain */ 880 h = rev[i].back; 881 rev[h].forw = j; 882 rev[j].back = h; 883 rev[i].forw = rev[i].back = i; 884 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j; 885 } 886 887 /* Now check and modify the HPTE */ 888 ptel = rev[i].guest_rpte; 889 psize = hpte_page_size(hptep[0], ptel); 890 if ((hptep[0] & HPTE_V_VALID) && 891 hpte_rpn(ptel, psize) == gfn) { 892 if (kvm->arch.using_mmu_notifiers) 893 hptep[0] |= HPTE_V_ABSENT; 894 kvmppc_invalidate_hpte(kvm, hptep, i); 895 /* Harvest R and C */ 896 rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C); 897 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT; 898 if (rcbits & ~rev[i].guest_rpte) { 899 rev[i].guest_rpte = ptel | rcbits; 900 note_hpte_modification(kvm, &rev[i]); 901 } 902 } 903 unlock_rmap(rmapp); 904 hptep[0] &= ~HPTE_V_HVLOCK; 905 } 906 return 0; 907 } 908 909 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) 910 { 911 if (kvm->arch.using_mmu_notifiers) 912 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 913 return 0; 914 } 915 916 int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end) 917 { 918 if (kvm->arch.using_mmu_notifiers) 919 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp); 920 return 0; 921 } 922 923 void kvmppc_core_flush_memslot(struct kvm *kvm, struct kvm_memory_slot *memslot) 924 { 925 unsigned long *rmapp; 926 unsigned long gfn; 927 unsigned long n; 928 929 rmapp = memslot->arch.rmap; 930 gfn = memslot->base_gfn; 931 for (n = memslot->npages; n; --n) { 932 /* 933 * Testing the present bit without locking is OK because 934 * the memslot has been marked invalid already, and hence 935 * no new HPTEs referencing this page can be created, 936 * thus the present bit can't go from 0 to 1. 937 */ 938 if (*rmapp & KVMPPC_RMAP_PRESENT) 939 kvm_unmap_rmapp(kvm, rmapp, gfn); 940 ++rmapp; 941 ++gfn; 942 } 943 } 944 945 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 946 unsigned long gfn) 947 { 948 struct revmap_entry *rev = kvm->arch.revmap; 949 unsigned long head, i, j; 950 unsigned long *hptep; 951 int ret = 0; 952 953 retry: 954 lock_rmap(rmapp); 955 if (*rmapp & KVMPPC_RMAP_REFERENCED) { 956 *rmapp &= ~KVMPPC_RMAP_REFERENCED; 957 ret = 1; 958 } 959 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 960 unlock_rmap(rmapp); 961 return ret; 962 } 963 964 i = head = *rmapp & KVMPPC_RMAP_INDEX; 965 do { 966 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 967 j = rev[i].forw; 968 969 /* If this HPTE isn't referenced, ignore it */ 970 if (!(hptep[1] & HPTE_R_R)) 971 continue; 972 973 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 974 /* unlock rmap before spinning on the HPTE lock */ 975 unlock_rmap(rmapp); 976 while (hptep[0] & HPTE_V_HVLOCK) 977 cpu_relax(); 978 goto retry; 979 } 980 981 /* Now check and modify the HPTE */ 982 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) { 983 kvmppc_clear_ref_hpte(kvm, hptep, i); 984 if (!(rev[i].guest_rpte & HPTE_R_R)) { 985 rev[i].guest_rpte |= HPTE_R_R; 986 note_hpte_modification(kvm, &rev[i]); 987 } 988 ret = 1; 989 } 990 hptep[0] &= ~HPTE_V_HVLOCK; 991 } while ((i = j) != head); 992 993 unlock_rmap(rmapp); 994 return ret; 995 } 996 997 int kvm_age_hva(struct kvm *kvm, unsigned long hva) 998 { 999 if (!kvm->arch.using_mmu_notifiers) 1000 return 0; 1001 return kvm_handle_hva(kvm, hva, kvm_age_rmapp); 1002 } 1003 1004 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 1005 unsigned long gfn) 1006 { 1007 struct revmap_entry *rev = kvm->arch.revmap; 1008 unsigned long head, i, j; 1009 unsigned long *hp; 1010 int ret = 1; 1011 1012 if (*rmapp & KVMPPC_RMAP_REFERENCED) 1013 return 1; 1014 1015 lock_rmap(rmapp); 1016 if (*rmapp & KVMPPC_RMAP_REFERENCED) 1017 goto out; 1018 1019 if (*rmapp & KVMPPC_RMAP_PRESENT) { 1020 i = head = *rmapp & KVMPPC_RMAP_INDEX; 1021 do { 1022 hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4)); 1023 j = rev[i].forw; 1024 if (hp[1] & HPTE_R_R) 1025 goto out; 1026 } while ((i = j) != head); 1027 } 1028 ret = 0; 1029 1030 out: 1031 unlock_rmap(rmapp); 1032 return ret; 1033 } 1034 1035 int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) 1036 { 1037 if (!kvm->arch.using_mmu_notifiers) 1038 return 0; 1039 return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp); 1040 } 1041 1042 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) 1043 { 1044 if (!kvm->arch.using_mmu_notifiers) 1045 return; 1046 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 1047 } 1048 1049 static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) 1050 { 1051 struct revmap_entry *rev = kvm->arch.revmap; 1052 unsigned long head, i, j; 1053 unsigned long *hptep; 1054 int ret = 0; 1055 1056 retry: 1057 lock_rmap(rmapp); 1058 if (*rmapp & KVMPPC_RMAP_CHANGED) { 1059 *rmapp &= ~KVMPPC_RMAP_CHANGED; 1060 ret = 1; 1061 } 1062 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 1063 unlock_rmap(rmapp); 1064 return ret; 1065 } 1066 1067 i = head = *rmapp & KVMPPC_RMAP_INDEX; 1068 do { 1069 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 1070 j = rev[i].forw; 1071 1072 if (!(hptep[1] & HPTE_R_C)) 1073 continue; 1074 1075 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 1076 /* unlock rmap before spinning on the HPTE lock */ 1077 unlock_rmap(rmapp); 1078 while (hptep[0] & HPTE_V_HVLOCK) 1079 cpu_relax(); 1080 goto retry; 1081 } 1082 1083 /* Now check and modify the HPTE */ 1084 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) { 1085 /* need to make it temporarily absent to clear C */ 1086 hptep[0] |= HPTE_V_ABSENT; 1087 kvmppc_invalidate_hpte(kvm, hptep, i); 1088 hptep[1] &= ~HPTE_R_C; 1089 eieio(); 1090 hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 1091 if (!(rev[i].guest_rpte & HPTE_R_C)) { 1092 rev[i].guest_rpte |= HPTE_R_C; 1093 note_hpte_modification(kvm, &rev[i]); 1094 } 1095 ret = 1; 1096 } 1097 hptep[0] &= ~HPTE_V_HVLOCK; 1098 } while ((i = j) != head); 1099 1100 unlock_rmap(rmapp); 1101 return ret; 1102 } 1103 1104 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, 1105 struct kvm_memory_slot *memslot, 1106 unsigned long *map) 1107 { 1108 unsigned long gfn; 1109 1110 if (!vpa->dirty || !vpa->pinned_addr) 1111 return; 1112 gfn = vpa->gpa >> PAGE_SHIFT; 1113 if (gfn < memslot->base_gfn || 1114 gfn >= memslot->base_gfn + memslot->npages) 1115 return; 1116 1117 vpa->dirty = false; 1118 if (map) 1119 __set_bit_le(gfn - memslot->base_gfn, map); 1120 } 1121 1122 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, 1123 unsigned long *map) 1124 { 1125 unsigned long i; 1126 unsigned long *rmapp; 1127 struct kvm_vcpu *vcpu; 1128 1129 preempt_disable(); 1130 rmapp = memslot->arch.rmap; 1131 for (i = 0; i < memslot->npages; ++i) { 1132 if (kvm_test_clear_dirty(kvm, rmapp) && map) 1133 __set_bit_le(i, map); 1134 ++rmapp; 1135 } 1136 1137 /* Harvest dirty bits from VPA and DTL updates */ 1138 /* Note: we never modify the SLB shadow buffer areas */ 1139 kvm_for_each_vcpu(i, vcpu, kvm) { 1140 spin_lock(&vcpu->arch.vpa_update_lock); 1141 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map); 1142 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map); 1143 spin_unlock(&vcpu->arch.vpa_update_lock); 1144 } 1145 preempt_enable(); 1146 return 0; 1147 } 1148 1149 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, 1150 unsigned long *nb_ret) 1151 { 1152 struct kvm_memory_slot *memslot; 1153 unsigned long gfn = gpa >> PAGE_SHIFT; 1154 struct page *page, *pages[1]; 1155 int npages; 1156 unsigned long hva, offset; 1157 unsigned long pa; 1158 unsigned long *physp; 1159 int srcu_idx; 1160 1161 srcu_idx = srcu_read_lock(&kvm->srcu); 1162 memslot = gfn_to_memslot(kvm, gfn); 1163 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 1164 goto err; 1165 if (!kvm->arch.using_mmu_notifiers) { 1166 physp = memslot->arch.slot_phys; 1167 if (!physp) 1168 goto err; 1169 physp += gfn - memslot->base_gfn; 1170 pa = *physp; 1171 if (!pa) { 1172 if (kvmppc_get_guest_page(kvm, gfn, memslot, 1173 PAGE_SIZE) < 0) 1174 goto err; 1175 pa = *physp; 1176 } 1177 page = pfn_to_page(pa >> PAGE_SHIFT); 1178 get_page(page); 1179 } else { 1180 hva = gfn_to_hva_memslot(memslot, gfn); 1181 npages = get_user_pages_fast(hva, 1, 1, pages); 1182 if (npages < 1) 1183 goto err; 1184 page = pages[0]; 1185 } 1186 srcu_read_unlock(&kvm->srcu, srcu_idx); 1187 1188 offset = gpa & (PAGE_SIZE - 1); 1189 if (nb_ret) 1190 *nb_ret = PAGE_SIZE - offset; 1191 return page_address(page) + offset; 1192 1193 err: 1194 srcu_read_unlock(&kvm->srcu, srcu_idx); 1195 return NULL; 1196 } 1197 1198 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa, 1199 bool dirty) 1200 { 1201 struct page *page = virt_to_page(va); 1202 struct kvm_memory_slot *memslot; 1203 unsigned long gfn; 1204 unsigned long *rmap; 1205 int srcu_idx; 1206 1207 put_page(page); 1208 1209 if (!dirty || !kvm->arch.using_mmu_notifiers) 1210 return; 1211 1212 /* We need to mark this page dirty in the rmap chain */ 1213 gfn = gpa >> PAGE_SHIFT; 1214 srcu_idx = srcu_read_lock(&kvm->srcu); 1215 memslot = gfn_to_memslot(kvm, gfn); 1216 if (memslot) { 1217 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 1218 lock_rmap(rmap); 1219 *rmap |= KVMPPC_RMAP_CHANGED; 1220 unlock_rmap(rmap); 1221 } 1222 srcu_read_unlock(&kvm->srcu, srcu_idx); 1223 } 1224 1225 /* 1226 * Functions for reading and writing the hash table via reads and 1227 * writes on a file descriptor. 1228 * 1229 * Reads return the guest view of the hash table, which has to be 1230 * pieced together from the real hash table and the guest_rpte 1231 * values in the revmap array. 1232 * 1233 * On writes, each HPTE written is considered in turn, and if it 1234 * is valid, it is written to the HPT as if an H_ENTER with the 1235 * exact flag set was done. When the invalid count is non-zero 1236 * in the header written to the stream, the kernel will make 1237 * sure that that many HPTEs are invalid, and invalidate them 1238 * if not. 1239 */ 1240 1241 struct kvm_htab_ctx { 1242 unsigned long index; 1243 unsigned long flags; 1244 struct kvm *kvm; 1245 int first_pass; 1246 }; 1247 1248 #define HPTE_SIZE (2 * sizeof(unsigned long)) 1249 1250 /* 1251 * Returns 1 if this HPT entry has been modified or has pending 1252 * R/C bit changes. 1253 */ 1254 static int hpte_dirty(struct revmap_entry *revp, unsigned long *hptp) 1255 { 1256 unsigned long rcbits_unset; 1257 1258 if (revp->guest_rpte & HPTE_GR_MODIFIED) 1259 return 1; 1260 1261 /* Also need to consider changes in reference and changed bits */ 1262 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1263 if ((hptp[0] & HPTE_V_VALID) && (hptp[1] & rcbits_unset)) 1264 return 1; 1265 1266 return 0; 1267 } 1268 1269 static long record_hpte(unsigned long flags, unsigned long *hptp, 1270 unsigned long *hpte, struct revmap_entry *revp, 1271 int want_valid, int first_pass) 1272 { 1273 unsigned long v, r; 1274 unsigned long rcbits_unset; 1275 int ok = 1; 1276 int valid, dirty; 1277 1278 /* Unmodified entries are uninteresting except on the first pass */ 1279 dirty = hpte_dirty(revp, hptp); 1280 if (!first_pass && !dirty) 1281 return 0; 1282 1283 valid = 0; 1284 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) { 1285 valid = 1; 1286 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && 1287 !(hptp[0] & HPTE_V_BOLTED)) 1288 valid = 0; 1289 } 1290 if (valid != want_valid) 1291 return 0; 1292 1293 v = r = 0; 1294 if (valid || dirty) { 1295 /* lock the HPTE so it's stable and read it */ 1296 preempt_disable(); 1297 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) 1298 cpu_relax(); 1299 v = hptp[0]; 1300 1301 /* re-evaluate valid and dirty from synchronized HPTE value */ 1302 valid = !!(v & HPTE_V_VALID); 1303 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); 1304 1305 /* Harvest R and C into guest view if necessary */ 1306 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1307 if (valid && (rcbits_unset & hptp[1])) { 1308 revp->guest_rpte |= (hptp[1] & (HPTE_R_R | HPTE_R_C)) | 1309 HPTE_GR_MODIFIED; 1310 dirty = 1; 1311 } 1312 1313 if (v & HPTE_V_ABSENT) { 1314 v &= ~HPTE_V_ABSENT; 1315 v |= HPTE_V_VALID; 1316 valid = 1; 1317 } 1318 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) 1319 valid = 0; 1320 1321 r = revp->guest_rpte; 1322 /* only clear modified if this is the right sort of entry */ 1323 if (valid == want_valid && dirty) { 1324 r &= ~HPTE_GR_MODIFIED; 1325 revp->guest_rpte = r; 1326 } 1327 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory"); 1328 hptp[0] &= ~HPTE_V_HVLOCK; 1329 preempt_enable(); 1330 if (!(valid == want_valid && (first_pass || dirty))) 1331 ok = 0; 1332 } 1333 hpte[0] = v; 1334 hpte[1] = r; 1335 return ok; 1336 } 1337 1338 static ssize_t kvm_htab_read(struct file *file, char __user *buf, 1339 size_t count, loff_t *ppos) 1340 { 1341 struct kvm_htab_ctx *ctx = file->private_data; 1342 struct kvm *kvm = ctx->kvm; 1343 struct kvm_get_htab_header hdr; 1344 unsigned long *hptp; 1345 struct revmap_entry *revp; 1346 unsigned long i, nb, nw; 1347 unsigned long __user *lbuf; 1348 struct kvm_get_htab_header __user *hptr; 1349 unsigned long flags; 1350 int first_pass; 1351 unsigned long hpte[2]; 1352 1353 if (!access_ok(VERIFY_WRITE, buf, count)) 1354 return -EFAULT; 1355 1356 first_pass = ctx->first_pass; 1357 flags = ctx->flags; 1358 1359 i = ctx->index; 1360 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1361 revp = kvm->arch.revmap + i; 1362 lbuf = (unsigned long __user *)buf; 1363 1364 nb = 0; 1365 while (nb + sizeof(hdr) + HPTE_SIZE < count) { 1366 /* Initialize header */ 1367 hptr = (struct kvm_get_htab_header __user *)buf; 1368 hdr.n_valid = 0; 1369 hdr.n_invalid = 0; 1370 nw = nb; 1371 nb += sizeof(hdr); 1372 lbuf = (unsigned long __user *)(buf + sizeof(hdr)); 1373 1374 /* Skip uninteresting entries, i.e. clean on not-first pass */ 1375 if (!first_pass) { 1376 while (i < kvm->arch.hpt_npte && 1377 !hpte_dirty(revp, hptp)) { 1378 ++i; 1379 hptp += 2; 1380 ++revp; 1381 } 1382 } 1383 hdr.index = i; 1384 1385 /* Grab a series of valid entries */ 1386 while (i < kvm->arch.hpt_npte && 1387 hdr.n_valid < 0xffff && 1388 nb + HPTE_SIZE < count && 1389 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) { 1390 /* valid entry, write it out */ 1391 ++hdr.n_valid; 1392 if (__put_user(hpte[0], lbuf) || 1393 __put_user(hpte[1], lbuf + 1)) 1394 return -EFAULT; 1395 nb += HPTE_SIZE; 1396 lbuf += 2; 1397 ++i; 1398 hptp += 2; 1399 ++revp; 1400 } 1401 /* Now skip invalid entries while we can */ 1402 while (i < kvm->arch.hpt_npte && 1403 hdr.n_invalid < 0xffff && 1404 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) { 1405 /* found an invalid entry */ 1406 ++hdr.n_invalid; 1407 ++i; 1408 hptp += 2; 1409 ++revp; 1410 } 1411 1412 if (hdr.n_valid || hdr.n_invalid) { 1413 /* write back the header */ 1414 if (__copy_to_user(hptr, &hdr, sizeof(hdr))) 1415 return -EFAULT; 1416 nw = nb; 1417 buf = (char __user *)lbuf; 1418 } else { 1419 nb = nw; 1420 } 1421 1422 /* Check if we've wrapped around the hash table */ 1423 if (i >= kvm->arch.hpt_npte) { 1424 i = 0; 1425 ctx->first_pass = 0; 1426 break; 1427 } 1428 } 1429 1430 ctx->index = i; 1431 1432 return nb; 1433 } 1434 1435 static ssize_t kvm_htab_write(struct file *file, const char __user *buf, 1436 size_t count, loff_t *ppos) 1437 { 1438 struct kvm_htab_ctx *ctx = file->private_data; 1439 struct kvm *kvm = ctx->kvm; 1440 struct kvm_get_htab_header hdr; 1441 unsigned long i, j; 1442 unsigned long v, r; 1443 unsigned long __user *lbuf; 1444 unsigned long *hptp; 1445 unsigned long tmp[2]; 1446 ssize_t nb; 1447 long int err, ret; 1448 int rma_setup; 1449 1450 if (!access_ok(VERIFY_READ, buf, count)) 1451 return -EFAULT; 1452 1453 /* lock out vcpus from running while we're doing this */ 1454 mutex_lock(&kvm->lock); 1455 rma_setup = kvm->arch.rma_setup_done; 1456 if (rma_setup) { 1457 kvm->arch.rma_setup_done = 0; /* temporarily */ 1458 /* order rma_setup_done vs. vcpus_running */ 1459 smp_mb(); 1460 if (atomic_read(&kvm->arch.vcpus_running)) { 1461 kvm->arch.rma_setup_done = 1; 1462 mutex_unlock(&kvm->lock); 1463 return -EBUSY; 1464 } 1465 } 1466 1467 err = 0; 1468 for (nb = 0; nb + sizeof(hdr) <= count; ) { 1469 err = -EFAULT; 1470 if (__copy_from_user(&hdr, buf, sizeof(hdr))) 1471 break; 1472 1473 err = 0; 1474 if (nb + hdr.n_valid * HPTE_SIZE > count) 1475 break; 1476 1477 nb += sizeof(hdr); 1478 buf += sizeof(hdr); 1479 1480 err = -EINVAL; 1481 i = hdr.index; 1482 if (i >= kvm->arch.hpt_npte || 1483 i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte) 1484 break; 1485 1486 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1487 lbuf = (unsigned long __user *)buf; 1488 for (j = 0; j < hdr.n_valid; ++j) { 1489 err = -EFAULT; 1490 if (__get_user(v, lbuf) || __get_user(r, lbuf + 1)) 1491 goto out; 1492 err = -EINVAL; 1493 if (!(v & HPTE_V_VALID)) 1494 goto out; 1495 lbuf += 2; 1496 nb += HPTE_SIZE; 1497 1498 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) 1499 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1500 err = -EIO; 1501 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r, 1502 tmp); 1503 if (ret != H_SUCCESS) { 1504 pr_err("kvm_htab_write ret %ld i=%ld v=%lx " 1505 "r=%lx\n", ret, i, v, r); 1506 goto out; 1507 } 1508 if (!rma_setup && is_vrma_hpte(v)) { 1509 unsigned long psize = hpte_page_size(v, r); 1510 unsigned long senc = slb_pgsize_encoding(psize); 1511 unsigned long lpcr; 1512 1513 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T | 1514 (VRMA_VSID << SLB_VSID_SHIFT_1T); 1515 lpcr = kvm->arch.lpcr & ~LPCR_VRMASD; 1516 lpcr |= senc << (LPCR_VRMASD_SH - 4); 1517 kvm->arch.lpcr = lpcr; 1518 rma_setup = 1; 1519 } 1520 ++i; 1521 hptp += 2; 1522 } 1523 1524 for (j = 0; j < hdr.n_invalid; ++j) { 1525 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) 1526 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1527 ++i; 1528 hptp += 2; 1529 } 1530 err = 0; 1531 } 1532 1533 out: 1534 /* Order HPTE updates vs. rma_setup_done */ 1535 smp_wmb(); 1536 kvm->arch.rma_setup_done = rma_setup; 1537 mutex_unlock(&kvm->lock); 1538 1539 if (err) 1540 return err; 1541 return nb; 1542 } 1543 1544 static int kvm_htab_release(struct inode *inode, struct file *filp) 1545 { 1546 struct kvm_htab_ctx *ctx = filp->private_data; 1547 1548 filp->private_data = NULL; 1549 if (!(ctx->flags & KVM_GET_HTAB_WRITE)) 1550 atomic_dec(&ctx->kvm->arch.hpte_mod_interest); 1551 kvm_put_kvm(ctx->kvm); 1552 kfree(ctx); 1553 return 0; 1554 } 1555 1556 static const struct file_operations kvm_htab_fops = { 1557 .read = kvm_htab_read, 1558 .write = kvm_htab_write, 1559 .llseek = default_llseek, 1560 .release = kvm_htab_release, 1561 }; 1562 1563 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf) 1564 { 1565 int ret; 1566 struct kvm_htab_ctx *ctx; 1567 int rwflag; 1568 1569 /* reject flags we don't recognize */ 1570 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE)) 1571 return -EINVAL; 1572 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 1573 if (!ctx) 1574 return -ENOMEM; 1575 kvm_get_kvm(kvm); 1576 ctx->kvm = kvm; 1577 ctx->index = ghf->start_index; 1578 ctx->flags = ghf->flags; 1579 ctx->first_pass = 1; 1580 1581 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY; 1582 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC); 1583 if (ret < 0) { 1584 kvm_put_kvm(kvm); 1585 return ret; 1586 } 1587 1588 if (rwflag == O_RDONLY) { 1589 mutex_lock(&kvm->slots_lock); 1590 atomic_inc(&kvm->arch.hpte_mod_interest); 1591 /* make sure kvmppc_do_h_enter etc. see the increment */ 1592 synchronize_srcu_expedited(&kvm->srcu); 1593 mutex_unlock(&kvm->slots_lock); 1594 } 1595 1596 return ret; 1597 } 1598 1599 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) 1600 { 1601 struct kvmppc_mmu *mmu = &vcpu->arch.mmu; 1602 1603 if (cpu_has_feature(CPU_FTR_ARCH_206)) 1604 vcpu->arch.slb_nr = 32; /* POWER7 */ 1605 else 1606 vcpu->arch.slb_nr = 64; 1607 1608 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate; 1609 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr; 1610 1611 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; 1612 } 1613