1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License, version 2, as 4 * published by the Free Software Foundation. 5 * 6 * This program is distributed in the hope that it will be useful, 7 * but WITHOUT ANY WARRANTY; without even the implied warranty of 8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 9 * GNU General Public License for more details. 10 * 11 * You should have received a copy of the GNU General Public License 12 * along with this program; if not, write to the Free Software 13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 14 * 15 * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> 16 */ 17 18 #include <linux/types.h> 19 #include <linux/string.h> 20 #include <linux/kvm.h> 21 #include <linux/kvm_host.h> 22 #include <linux/highmem.h> 23 #include <linux/gfp.h> 24 #include <linux/slab.h> 25 #include <linux/hugetlb.h> 26 #include <linux/vmalloc.h> 27 #include <linux/srcu.h> 28 #include <linux/anon_inodes.h> 29 #include <linux/file.h> 30 31 #include <asm/tlbflush.h> 32 #include <asm/kvm_ppc.h> 33 #include <asm/kvm_book3s.h> 34 #include <asm/mmu-hash64.h> 35 #include <asm/hvcall.h> 36 #include <asm/synch.h> 37 #include <asm/ppc-opcode.h> 38 #include <asm/cputable.h> 39 40 #include "book3s_hv_cma.h" 41 42 /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */ 43 #define MAX_LPID_970 63 44 45 /* Power architecture requires HPT is at least 256kB */ 46 #define PPC_MIN_HPT_ORDER 18 47 48 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 49 long pte_index, unsigned long pteh, 50 unsigned long ptel, unsigned long *pte_idx_ret); 51 static void kvmppc_rmap_reset(struct kvm *kvm); 52 53 long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp) 54 { 55 unsigned long hpt; 56 struct revmap_entry *rev; 57 struct page *page = NULL; 58 long order = KVM_DEFAULT_HPT_ORDER; 59 60 if (htab_orderp) { 61 order = *htab_orderp; 62 if (order < PPC_MIN_HPT_ORDER) 63 order = PPC_MIN_HPT_ORDER; 64 } 65 66 kvm->arch.hpt_cma_alloc = 0; 67 /* 68 * try first to allocate it from the kernel page allocator. 69 * We keep the CMA reserved for failed allocation. 70 */ 71 hpt = __get_free_pages(GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT | 72 __GFP_NOWARN, order - PAGE_SHIFT); 73 74 /* Next try to allocate from the preallocated pool */ 75 if (!hpt) { 76 VM_BUG_ON(order < KVM_CMA_CHUNK_ORDER); 77 page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT)); 78 if (page) { 79 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page)); 80 kvm->arch.hpt_cma_alloc = 1; 81 } else 82 --order; 83 } 84 85 /* Lastly try successively smaller sizes from the page allocator */ 86 while (!hpt && order > PPC_MIN_HPT_ORDER) { 87 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT| 88 __GFP_NOWARN, order - PAGE_SHIFT); 89 if (!hpt) 90 --order; 91 } 92 93 if (!hpt) 94 return -ENOMEM; 95 96 kvm->arch.hpt_virt = hpt; 97 kvm->arch.hpt_order = order; 98 /* HPTEs are 2**4 bytes long */ 99 kvm->arch.hpt_npte = 1ul << (order - 4); 100 /* 128 (2**7) bytes in each HPTEG */ 101 kvm->arch.hpt_mask = (1ul << (order - 7)) - 1; 102 103 /* Allocate reverse map array */ 104 rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte); 105 if (!rev) { 106 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n"); 107 goto out_freehpt; 108 } 109 kvm->arch.revmap = rev; 110 kvm->arch.sdr1 = __pa(hpt) | (order - 18); 111 112 pr_info("KVM guest htab at %lx (order %ld), LPID %x\n", 113 hpt, order, kvm->arch.lpid); 114 115 if (htab_orderp) 116 *htab_orderp = order; 117 return 0; 118 119 out_freehpt: 120 if (kvm->arch.hpt_cma_alloc) 121 kvm_release_hpt(page, 1 << (order - PAGE_SHIFT)); 122 else 123 free_pages(hpt, order - PAGE_SHIFT); 124 return -ENOMEM; 125 } 126 127 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp) 128 { 129 long err = -EBUSY; 130 long order; 131 132 mutex_lock(&kvm->lock); 133 if (kvm->arch.rma_setup_done) { 134 kvm->arch.rma_setup_done = 0; 135 /* order rma_setup_done vs. vcpus_running */ 136 smp_mb(); 137 if (atomic_read(&kvm->arch.vcpus_running)) { 138 kvm->arch.rma_setup_done = 1; 139 goto out; 140 } 141 } 142 if (kvm->arch.hpt_virt) { 143 order = kvm->arch.hpt_order; 144 /* Set the entire HPT to 0, i.e. invalid HPTEs */ 145 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order); 146 /* 147 * Reset all the reverse-mapping chains for all memslots 148 */ 149 kvmppc_rmap_reset(kvm); 150 /* Ensure that each vcpu will flush its TLB on next entry. */ 151 cpumask_setall(&kvm->arch.need_tlb_flush); 152 *htab_orderp = order; 153 err = 0; 154 } else { 155 err = kvmppc_alloc_hpt(kvm, htab_orderp); 156 order = *htab_orderp; 157 } 158 out: 159 mutex_unlock(&kvm->lock); 160 return err; 161 } 162 163 void kvmppc_free_hpt(struct kvm *kvm) 164 { 165 kvmppc_free_lpid(kvm->arch.lpid); 166 vfree(kvm->arch.revmap); 167 if (kvm->arch.hpt_cma_alloc) 168 kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt), 169 1 << (kvm->arch.hpt_order - PAGE_SHIFT)); 170 else 171 free_pages(kvm->arch.hpt_virt, 172 kvm->arch.hpt_order - PAGE_SHIFT); 173 } 174 175 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */ 176 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize) 177 { 178 return (pgsize > 0x1000) ? HPTE_V_LARGE : 0; 179 } 180 181 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */ 182 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize) 183 { 184 return (pgsize == 0x10000) ? 0x1000 : 0; 185 } 186 187 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, 188 unsigned long porder) 189 { 190 unsigned long i; 191 unsigned long npages; 192 unsigned long hp_v, hp_r; 193 unsigned long addr, hash; 194 unsigned long psize; 195 unsigned long hp0, hp1; 196 unsigned long idx_ret; 197 long ret; 198 struct kvm *kvm = vcpu->kvm; 199 200 psize = 1ul << porder; 201 npages = memslot->npages >> (porder - PAGE_SHIFT); 202 203 /* VRMA can't be > 1TB */ 204 if (npages > 1ul << (40 - porder)) 205 npages = 1ul << (40 - porder); 206 /* Can't use more than 1 HPTE per HPTEG */ 207 if (npages > kvm->arch.hpt_mask + 1) 208 npages = kvm->arch.hpt_mask + 1; 209 210 hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) | 211 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize); 212 hp1 = hpte1_pgsize_encoding(psize) | 213 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX; 214 215 for (i = 0; i < npages; ++i) { 216 addr = i << porder; 217 /* can't use hpt_hash since va > 64 bits */ 218 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask; 219 /* 220 * We assume that the hash table is empty and no 221 * vcpus are using it at this stage. Since we create 222 * at most one HPTE per HPTEG, we just assume entry 7 223 * is available and use it. 224 */ 225 hash = (hash << 3) + 7; 226 hp_v = hp0 | ((addr >> 16) & ~0x7fUL); 227 hp_r = hp1 | addr; 228 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r, 229 &idx_ret); 230 if (ret != H_SUCCESS) { 231 pr_err("KVM: map_vrma at %lx failed, ret=%ld\n", 232 addr, ret); 233 break; 234 } 235 } 236 } 237 238 int kvmppc_mmu_hv_init(void) 239 { 240 unsigned long host_lpid, rsvd_lpid; 241 242 if (!cpu_has_feature(CPU_FTR_HVMODE)) 243 return -EINVAL; 244 245 /* POWER7 has 10-bit LPIDs, PPC970 and e500mc have 6-bit LPIDs */ 246 if (cpu_has_feature(CPU_FTR_ARCH_206)) { 247 host_lpid = mfspr(SPRN_LPID); /* POWER7 */ 248 rsvd_lpid = LPID_RSVD; 249 } else { 250 host_lpid = 0; /* PPC970 */ 251 rsvd_lpid = MAX_LPID_970; 252 } 253 254 kvmppc_init_lpid(rsvd_lpid + 1); 255 256 kvmppc_claim_lpid(host_lpid); 257 /* rsvd_lpid is reserved for use in partition switching */ 258 kvmppc_claim_lpid(rsvd_lpid); 259 260 return 0; 261 } 262 263 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu) 264 { 265 kvmppc_set_msr(vcpu, MSR_SF | MSR_ME); 266 } 267 268 /* 269 * This is called to get a reference to a guest page if there isn't 270 * one already in the memslot->arch.slot_phys[] array. 271 */ 272 static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn, 273 struct kvm_memory_slot *memslot, 274 unsigned long psize) 275 { 276 unsigned long start; 277 long np, err; 278 struct page *page, *hpage, *pages[1]; 279 unsigned long s, pgsize; 280 unsigned long *physp; 281 unsigned int is_io, got, pgorder; 282 struct vm_area_struct *vma; 283 unsigned long pfn, i, npages; 284 285 physp = memslot->arch.slot_phys; 286 if (!physp) 287 return -EINVAL; 288 if (physp[gfn - memslot->base_gfn]) 289 return 0; 290 291 is_io = 0; 292 got = 0; 293 page = NULL; 294 pgsize = psize; 295 err = -EINVAL; 296 start = gfn_to_hva_memslot(memslot, gfn); 297 298 /* Instantiate and get the page we want access to */ 299 np = get_user_pages_fast(start, 1, 1, pages); 300 if (np != 1) { 301 /* Look up the vma for the page */ 302 down_read(¤t->mm->mmap_sem); 303 vma = find_vma(current->mm, start); 304 if (!vma || vma->vm_start > start || 305 start + psize > vma->vm_end || 306 !(vma->vm_flags & VM_PFNMAP)) 307 goto up_err; 308 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot)); 309 pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); 310 /* check alignment of pfn vs. requested page size */ 311 if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1))) 312 goto up_err; 313 up_read(¤t->mm->mmap_sem); 314 315 } else { 316 page = pages[0]; 317 got = KVMPPC_GOT_PAGE; 318 319 /* See if this is a large page */ 320 s = PAGE_SIZE; 321 if (PageHuge(page)) { 322 hpage = compound_head(page); 323 s <<= compound_order(hpage); 324 /* Get the whole large page if slot alignment is ok */ 325 if (s > psize && slot_is_aligned(memslot, s) && 326 !(memslot->userspace_addr & (s - 1))) { 327 start &= ~(s - 1); 328 pgsize = s; 329 get_page(hpage); 330 put_page(page); 331 page = hpage; 332 } 333 } 334 if (s < psize) 335 goto out; 336 pfn = page_to_pfn(page); 337 } 338 339 npages = pgsize >> PAGE_SHIFT; 340 pgorder = __ilog2(npages); 341 physp += (gfn - memslot->base_gfn) & ~(npages - 1); 342 spin_lock(&kvm->arch.slot_phys_lock); 343 for (i = 0; i < npages; ++i) { 344 if (!physp[i]) { 345 physp[i] = ((pfn + i) << PAGE_SHIFT) + 346 got + is_io + pgorder; 347 got = 0; 348 } 349 } 350 spin_unlock(&kvm->arch.slot_phys_lock); 351 err = 0; 352 353 out: 354 if (got) 355 put_page(page); 356 return err; 357 358 up_err: 359 up_read(¤t->mm->mmap_sem); 360 return err; 361 } 362 363 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 364 long pte_index, unsigned long pteh, 365 unsigned long ptel, unsigned long *pte_idx_ret) 366 { 367 unsigned long psize, gpa, gfn; 368 struct kvm_memory_slot *memslot; 369 long ret; 370 371 if (kvm->arch.using_mmu_notifiers) 372 goto do_insert; 373 374 psize = hpte_page_size(pteh, ptel); 375 if (!psize) 376 return H_PARAMETER; 377 378 pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID); 379 380 /* Find the memslot (if any) for this address */ 381 gpa = (ptel & HPTE_R_RPN) & ~(psize - 1); 382 gfn = gpa >> PAGE_SHIFT; 383 memslot = gfn_to_memslot(kvm, gfn); 384 if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) { 385 if (!slot_is_aligned(memslot, psize)) 386 return H_PARAMETER; 387 if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0) 388 return H_PARAMETER; 389 } 390 391 do_insert: 392 /* Protect linux PTE lookup from page table destruction */ 393 rcu_read_lock_sched(); /* this disables preemption too */ 394 ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel, 395 current->mm->pgd, false, pte_idx_ret); 396 rcu_read_unlock_sched(); 397 if (ret == H_TOO_HARD) { 398 /* this can't happen */ 399 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n"); 400 ret = H_RESOURCE; /* or something */ 401 } 402 return ret; 403 404 } 405 406 /* 407 * We come here on a H_ENTER call from the guest when we are not 408 * using mmu notifiers and we don't have the requested page pinned 409 * already. 410 */ 411 long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, 412 long pte_index, unsigned long pteh, 413 unsigned long ptel) 414 { 415 return kvmppc_virtmode_do_h_enter(vcpu->kvm, flags, pte_index, 416 pteh, ptel, &vcpu->arch.gpr[4]); 417 } 418 419 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu, 420 gva_t eaddr) 421 { 422 u64 mask; 423 int i; 424 425 for (i = 0; i < vcpu->arch.slb_nr; i++) { 426 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V)) 427 continue; 428 429 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T) 430 mask = ESID_MASK_1T; 431 else 432 mask = ESID_MASK; 433 434 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0) 435 return &vcpu->arch.slb[i]; 436 } 437 return NULL; 438 } 439 440 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r, 441 unsigned long ea) 442 { 443 unsigned long ra_mask; 444 445 ra_mask = hpte_page_size(v, r) - 1; 446 return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask); 447 } 448 449 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, 450 struct kvmppc_pte *gpte, bool data, bool iswrite) 451 { 452 struct kvm *kvm = vcpu->kvm; 453 struct kvmppc_slb *slbe; 454 unsigned long slb_v; 455 unsigned long pp, key; 456 unsigned long v, gr; 457 unsigned long *hptep; 458 int index; 459 int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR); 460 461 /* Get SLB entry */ 462 if (virtmode) { 463 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr); 464 if (!slbe) 465 return -EINVAL; 466 slb_v = slbe->origv; 467 } else { 468 /* real mode access */ 469 slb_v = vcpu->kvm->arch.vrma_slb_v; 470 } 471 472 preempt_disable(); 473 /* Find the HPTE in the hash table */ 474 index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, 475 HPTE_V_VALID | HPTE_V_ABSENT); 476 if (index < 0) { 477 preempt_enable(); 478 return -ENOENT; 479 } 480 hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); 481 v = hptep[0] & ~HPTE_V_HVLOCK; 482 gr = kvm->arch.revmap[index].guest_rpte; 483 484 /* Unlock the HPTE */ 485 asm volatile("lwsync" : : : "memory"); 486 hptep[0] = v; 487 preempt_enable(); 488 489 gpte->eaddr = eaddr; 490 gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff); 491 492 /* Get PP bits and key for permission check */ 493 pp = gr & (HPTE_R_PP0 | HPTE_R_PP); 494 key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS; 495 key &= slb_v; 496 497 /* Calculate permissions */ 498 gpte->may_read = hpte_read_permission(pp, key); 499 gpte->may_write = hpte_write_permission(pp, key); 500 gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G)); 501 502 /* Storage key permission check for POWER7 */ 503 if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) { 504 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr); 505 if (amrfield & 1) 506 gpte->may_read = 0; 507 if (amrfield & 2) 508 gpte->may_write = 0; 509 } 510 511 /* Get the guest physical address */ 512 gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr); 513 return 0; 514 } 515 516 /* 517 * Quick test for whether an instruction is a load or a store. 518 * If the instruction is a load or a store, then this will indicate 519 * which it is, at least on server processors. (Embedded processors 520 * have some external PID instructions that don't follow the rule 521 * embodied here.) If the instruction isn't a load or store, then 522 * this doesn't return anything useful. 523 */ 524 static int instruction_is_store(unsigned int instr) 525 { 526 unsigned int mask; 527 528 mask = 0x10000000; 529 if ((instr & 0xfc000000) == 0x7c000000) 530 mask = 0x100; /* major opcode 31 */ 531 return (instr & mask) != 0; 532 } 533 534 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, 535 unsigned long gpa, gva_t ea, int is_store) 536 { 537 int ret; 538 u32 last_inst; 539 unsigned long srr0 = kvmppc_get_pc(vcpu); 540 541 /* We try to load the last instruction. We don't let 542 * emulate_instruction do it as it doesn't check what 543 * kvmppc_ld returns. 544 * If we fail, we just return to the guest and try executing it again. 545 */ 546 if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) { 547 ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false); 548 if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED) 549 return RESUME_GUEST; 550 vcpu->arch.last_inst = last_inst; 551 } 552 553 /* 554 * WARNING: We do not know for sure whether the instruction we just 555 * read from memory is the same that caused the fault in the first 556 * place. If the instruction we read is neither an load or a store, 557 * then it can't access memory, so we don't need to worry about 558 * enforcing access permissions. So, assuming it is a load or 559 * store, we just check that its direction (load or store) is 560 * consistent with the original fault, since that's what we 561 * checked the access permissions against. If there is a mismatch 562 * we just return and retry the instruction. 563 */ 564 565 if (instruction_is_store(vcpu->arch.last_inst) != !!is_store) 566 return RESUME_GUEST; 567 568 /* 569 * Emulated accesses are emulated by looking at the hash for 570 * translation once, then performing the access later. The 571 * translation could be invalidated in the meantime in which 572 * point performing the subsequent memory access on the old 573 * physical address could possibly be a security hole for the 574 * guest (but not the host). 575 * 576 * This is less of an issue for MMIO stores since they aren't 577 * globally visible. It could be an issue for MMIO loads to 578 * a certain extent but we'll ignore it for now. 579 */ 580 581 vcpu->arch.paddr_accessed = gpa; 582 vcpu->arch.vaddr_accessed = ea; 583 return kvmppc_emulate_mmio(run, vcpu); 584 } 585 586 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 587 unsigned long ea, unsigned long dsisr) 588 { 589 struct kvm *kvm = vcpu->kvm; 590 unsigned long *hptep, hpte[3], r; 591 unsigned long mmu_seq, psize, pte_size; 592 unsigned long gpa, gfn, hva, pfn; 593 struct kvm_memory_slot *memslot; 594 unsigned long *rmap; 595 struct revmap_entry *rev; 596 struct page *page, *pages[1]; 597 long index, ret, npages; 598 unsigned long is_io; 599 unsigned int writing, write_ok; 600 struct vm_area_struct *vma; 601 unsigned long rcbits; 602 603 /* 604 * Real-mode code has already searched the HPT and found the 605 * entry we're interested in. Lock the entry and check that 606 * it hasn't changed. If it has, just return and re-execute the 607 * instruction. 608 */ 609 if (ea != vcpu->arch.pgfault_addr) 610 return RESUME_GUEST; 611 index = vcpu->arch.pgfault_index; 612 hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); 613 rev = &kvm->arch.revmap[index]; 614 preempt_disable(); 615 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 616 cpu_relax(); 617 hpte[0] = hptep[0] & ~HPTE_V_HVLOCK; 618 hpte[1] = hptep[1]; 619 hpte[2] = r = rev->guest_rpte; 620 asm volatile("lwsync" : : : "memory"); 621 hptep[0] = hpte[0]; 622 preempt_enable(); 623 624 if (hpte[0] != vcpu->arch.pgfault_hpte[0] || 625 hpte[1] != vcpu->arch.pgfault_hpte[1]) 626 return RESUME_GUEST; 627 628 /* Translate the logical address and get the page */ 629 psize = hpte_page_size(hpte[0], r); 630 gpa = (r & HPTE_R_RPN & ~(psize - 1)) | (ea & (psize - 1)); 631 gfn = gpa >> PAGE_SHIFT; 632 memslot = gfn_to_memslot(kvm, gfn); 633 634 /* No memslot means it's an emulated MMIO region */ 635 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 636 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, 637 dsisr & DSISR_ISSTORE); 638 639 if (!kvm->arch.using_mmu_notifiers) 640 return -EFAULT; /* should never get here */ 641 642 /* used to check for invalidations in progress */ 643 mmu_seq = kvm->mmu_notifier_seq; 644 smp_rmb(); 645 646 is_io = 0; 647 pfn = 0; 648 page = NULL; 649 pte_size = PAGE_SIZE; 650 writing = (dsisr & DSISR_ISSTORE) != 0; 651 /* If writing != 0, then the HPTE must allow writing, if we get here */ 652 write_ok = writing; 653 hva = gfn_to_hva_memslot(memslot, gfn); 654 npages = get_user_pages_fast(hva, 1, writing, pages); 655 if (npages < 1) { 656 /* Check if it's an I/O mapping */ 657 down_read(¤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 pfn = page_to_pfn(page); 673 if (PageHuge(page)) { 674 page = compound_head(page); 675 pte_size <<= compound_order(page); 676 } 677 /* if the guest wants write access, see if that is OK */ 678 if (!writing && hpte_is_writable(r)) { 679 unsigned int hugepage_shift; 680 pte_t *ptep, pte; 681 682 /* 683 * We need to protect against page table destruction 684 * while looking up and updating the pte. 685 */ 686 rcu_read_lock_sched(); 687 ptep = find_linux_pte_or_hugepte(current->mm->pgd, 688 hva, &hugepage_shift); 689 if (ptep) { 690 pte = kvmppc_read_update_linux_pte(ptep, 1, 691 hugepage_shift); 692 if (pte_write(pte)) 693 write_ok = 1; 694 } 695 rcu_read_unlock_sched(); 696 } 697 } 698 699 ret = -EFAULT; 700 if (psize > pte_size) 701 goto out_put; 702 703 /* Check WIMG vs. the actual page we're accessing */ 704 if (!hpte_cache_flags_ok(r, is_io)) { 705 if (is_io) 706 return -EFAULT; 707 /* 708 * Allow guest to map emulated device memory as 709 * uncacheable, but actually make it cacheable. 710 */ 711 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M; 712 } 713 714 /* 715 * Set the HPTE to point to pfn. 716 * Since the pfn is at PAGE_SIZE granularity, make sure we 717 * don't mask out lower-order bits if psize < PAGE_SIZE. 718 */ 719 if (psize < PAGE_SIZE) 720 psize = PAGE_SIZE; 721 r = (r & ~(HPTE_R_PP0 - psize)) | ((pfn << PAGE_SHIFT) & ~(psize - 1)); 722 if (hpte_is_writable(r) && !write_ok) 723 r = hpte_make_readonly(r); 724 ret = RESUME_GUEST; 725 preempt_disable(); 726 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 727 cpu_relax(); 728 if ((hptep[0] & ~HPTE_V_HVLOCK) != hpte[0] || hptep[1] != hpte[1] || 729 rev->guest_rpte != hpte[2]) 730 /* HPTE has been changed under us; let the guest retry */ 731 goto out_unlock; 732 hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 733 734 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 735 lock_rmap(rmap); 736 737 /* Check if we might have been invalidated; let the guest retry if so */ 738 ret = RESUME_GUEST; 739 if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) { 740 unlock_rmap(rmap); 741 goto out_unlock; 742 } 743 744 /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */ 745 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT; 746 r &= rcbits | ~(HPTE_R_R | HPTE_R_C); 747 748 if (hptep[0] & HPTE_V_VALID) { 749 /* HPTE was previously valid, so we need to invalidate it */ 750 unlock_rmap(rmap); 751 hptep[0] |= HPTE_V_ABSENT; 752 kvmppc_invalidate_hpte(kvm, hptep, index); 753 /* don't lose previous R and C bits */ 754 r |= hptep[1] & (HPTE_R_R | HPTE_R_C); 755 } else { 756 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0); 757 } 758 759 hptep[1] = r; 760 eieio(); 761 hptep[0] = hpte[0]; 762 asm volatile("ptesync" : : : "memory"); 763 preempt_enable(); 764 if (page && hpte_is_writable(r)) 765 SetPageDirty(page); 766 767 out_put: 768 if (page) { 769 /* 770 * We drop pages[0] here, not page because page might 771 * have been set to the head page of a compound, but 772 * we have to drop the reference on the correct tail 773 * page to match the get inside gup() 774 */ 775 put_page(pages[0]); 776 } 777 return ret; 778 779 out_unlock: 780 hptep[0] &= ~HPTE_V_HVLOCK; 781 preempt_enable(); 782 goto out_put; 783 } 784 785 static void kvmppc_rmap_reset(struct kvm *kvm) 786 { 787 struct kvm_memslots *slots; 788 struct kvm_memory_slot *memslot; 789 int srcu_idx; 790 791 srcu_idx = srcu_read_lock(&kvm->srcu); 792 slots = kvm->memslots; 793 kvm_for_each_memslot(memslot, slots) { 794 /* 795 * This assumes it is acceptable to lose reference and 796 * change bits across a reset. 797 */ 798 memset(memslot->arch.rmap, 0, 799 memslot->npages * sizeof(*memslot->arch.rmap)); 800 } 801 srcu_read_unlock(&kvm->srcu, srcu_idx); 802 } 803 804 static int kvm_handle_hva_range(struct kvm *kvm, 805 unsigned long start, 806 unsigned long end, 807 int (*handler)(struct kvm *kvm, 808 unsigned long *rmapp, 809 unsigned long gfn)) 810 { 811 int ret; 812 int retval = 0; 813 struct kvm_memslots *slots; 814 struct kvm_memory_slot *memslot; 815 816 slots = kvm_memslots(kvm); 817 kvm_for_each_memslot(memslot, slots) { 818 unsigned long hva_start, hva_end; 819 gfn_t gfn, gfn_end; 820 821 hva_start = max(start, memslot->userspace_addr); 822 hva_end = min(end, memslot->userspace_addr + 823 (memslot->npages << PAGE_SHIFT)); 824 if (hva_start >= hva_end) 825 continue; 826 /* 827 * {gfn(page) | page intersects with [hva_start, hva_end)} = 828 * {gfn, gfn+1, ..., gfn_end-1}. 829 */ 830 gfn = hva_to_gfn_memslot(hva_start, memslot); 831 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); 832 833 for (; gfn < gfn_end; ++gfn) { 834 gfn_t gfn_offset = gfn - memslot->base_gfn; 835 836 ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn); 837 retval |= ret; 838 } 839 } 840 841 return retval; 842 } 843 844 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, 845 int (*handler)(struct kvm *kvm, unsigned long *rmapp, 846 unsigned long gfn)) 847 { 848 return kvm_handle_hva_range(kvm, hva, hva + 1, handler); 849 } 850 851 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, 852 unsigned long gfn) 853 { 854 struct revmap_entry *rev = kvm->arch.revmap; 855 unsigned long h, i, j; 856 unsigned long *hptep; 857 unsigned long ptel, psize, rcbits; 858 859 for (;;) { 860 lock_rmap(rmapp); 861 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 862 unlock_rmap(rmapp); 863 break; 864 } 865 866 /* 867 * To avoid an ABBA deadlock with the HPTE lock bit, 868 * we can't spin on the HPTE lock while holding the 869 * rmap chain lock. 870 */ 871 i = *rmapp & KVMPPC_RMAP_INDEX; 872 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 873 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 874 /* unlock rmap before spinning on the HPTE lock */ 875 unlock_rmap(rmapp); 876 while (hptep[0] & HPTE_V_HVLOCK) 877 cpu_relax(); 878 continue; 879 } 880 j = rev[i].forw; 881 if (j == i) { 882 /* chain is now empty */ 883 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX); 884 } else { 885 /* remove i from chain */ 886 h = rev[i].back; 887 rev[h].forw = j; 888 rev[j].back = h; 889 rev[i].forw = rev[i].back = i; 890 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j; 891 } 892 893 /* Now check and modify the HPTE */ 894 ptel = rev[i].guest_rpte; 895 psize = hpte_page_size(hptep[0], ptel); 896 if ((hptep[0] & HPTE_V_VALID) && 897 hpte_rpn(ptel, psize) == gfn) { 898 if (kvm->arch.using_mmu_notifiers) 899 hptep[0] |= HPTE_V_ABSENT; 900 kvmppc_invalidate_hpte(kvm, hptep, i); 901 /* Harvest R and C */ 902 rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C); 903 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT; 904 if (rcbits & ~rev[i].guest_rpte) { 905 rev[i].guest_rpte = ptel | rcbits; 906 note_hpte_modification(kvm, &rev[i]); 907 } 908 } 909 unlock_rmap(rmapp); 910 hptep[0] &= ~HPTE_V_HVLOCK; 911 } 912 return 0; 913 } 914 915 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva) 916 { 917 if (kvm->arch.using_mmu_notifiers) 918 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 919 return 0; 920 } 921 922 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end) 923 { 924 if (kvm->arch.using_mmu_notifiers) 925 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp); 926 return 0; 927 } 928 929 void kvmppc_core_flush_memslot_hv(struct kvm *kvm, 930 struct kvm_memory_slot *memslot) 931 { 932 unsigned long *rmapp; 933 unsigned long gfn; 934 unsigned long n; 935 936 rmapp = memslot->arch.rmap; 937 gfn = memslot->base_gfn; 938 for (n = memslot->npages; n; --n) { 939 /* 940 * Testing the present bit without locking is OK because 941 * the memslot has been marked invalid already, and hence 942 * no new HPTEs referencing this page can be created, 943 * thus the present bit can't go from 0 to 1. 944 */ 945 if (*rmapp & KVMPPC_RMAP_PRESENT) 946 kvm_unmap_rmapp(kvm, rmapp, gfn); 947 ++rmapp; 948 ++gfn; 949 } 950 } 951 952 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 953 unsigned long gfn) 954 { 955 struct revmap_entry *rev = kvm->arch.revmap; 956 unsigned long head, i, j; 957 unsigned long *hptep; 958 int ret = 0; 959 960 retry: 961 lock_rmap(rmapp); 962 if (*rmapp & KVMPPC_RMAP_REFERENCED) { 963 *rmapp &= ~KVMPPC_RMAP_REFERENCED; 964 ret = 1; 965 } 966 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 967 unlock_rmap(rmapp); 968 return ret; 969 } 970 971 i = head = *rmapp & KVMPPC_RMAP_INDEX; 972 do { 973 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 974 j = rev[i].forw; 975 976 /* If this HPTE isn't referenced, ignore it */ 977 if (!(hptep[1] & HPTE_R_R)) 978 continue; 979 980 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 981 /* unlock rmap before spinning on the HPTE lock */ 982 unlock_rmap(rmapp); 983 while (hptep[0] & HPTE_V_HVLOCK) 984 cpu_relax(); 985 goto retry; 986 } 987 988 /* Now check and modify the HPTE */ 989 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) { 990 kvmppc_clear_ref_hpte(kvm, hptep, i); 991 if (!(rev[i].guest_rpte & HPTE_R_R)) { 992 rev[i].guest_rpte |= HPTE_R_R; 993 note_hpte_modification(kvm, &rev[i]); 994 } 995 ret = 1; 996 } 997 hptep[0] &= ~HPTE_V_HVLOCK; 998 } while ((i = j) != head); 999 1000 unlock_rmap(rmapp); 1001 return ret; 1002 } 1003 1004 int kvm_age_hva_hv(struct kvm *kvm, unsigned long hva) 1005 { 1006 if (!kvm->arch.using_mmu_notifiers) 1007 return 0; 1008 return kvm_handle_hva(kvm, hva, kvm_age_rmapp); 1009 } 1010 1011 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 1012 unsigned long gfn) 1013 { 1014 struct revmap_entry *rev = kvm->arch.revmap; 1015 unsigned long head, i, j; 1016 unsigned long *hp; 1017 int ret = 1; 1018 1019 if (*rmapp & KVMPPC_RMAP_REFERENCED) 1020 return 1; 1021 1022 lock_rmap(rmapp); 1023 if (*rmapp & KVMPPC_RMAP_REFERENCED) 1024 goto out; 1025 1026 if (*rmapp & KVMPPC_RMAP_PRESENT) { 1027 i = head = *rmapp & KVMPPC_RMAP_INDEX; 1028 do { 1029 hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4)); 1030 j = rev[i].forw; 1031 if (hp[1] & HPTE_R_R) 1032 goto out; 1033 } while ((i = j) != head); 1034 } 1035 ret = 0; 1036 1037 out: 1038 unlock_rmap(rmapp); 1039 return ret; 1040 } 1041 1042 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva) 1043 { 1044 if (!kvm->arch.using_mmu_notifiers) 1045 return 0; 1046 return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp); 1047 } 1048 1049 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte) 1050 { 1051 if (!kvm->arch.using_mmu_notifiers) 1052 return; 1053 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 1054 } 1055 1056 static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) 1057 { 1058 struct revmap_entry *rev = kvm->arch.revmap; 1059 unsigned long head, i, j; 1060 unsigned long *hptep; 1061 int ret = 0; 1062 1063 retry: 1064 lock_rmap(rmapp); 1065 if (*rmapp & KVMPPC_RMAP_CHANGED) { 1066 *rmapp &= ~KVMPPC_RMAP_CHANGED; 1067 ret = 1; 1068 } 1069 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 1070 unlock_rmap(rmapp); 1071 return ret; 1072 } 1073 1074 i = head = *rmapp & KVMPPC_RMAP_INDEX; 1075 do { 1076 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 1077 j = rev[i].forw; 1078 1079 if (!(hptep[1] & HPTE_R_C)) 1080 continue; 1081 1082 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 1083 /* unlock rmap before spinning on the HPTE lock */ 1084 unlock_rmap(rmapp); 1085 while (hptep[0] & HPTE_V_HVLOCK) 1086 cpu_relax(); 1087 goto retry; 1088 } 1089 1090 /* Now check and modify the HPTE */ 1091 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) { 1092 /* need to make it temporarily absent to clear C */ 1093 hptep[0] |= HPTE_V_ABSENT; 1094 kvmppc_invalidate_hpte(kvm, hptep, i); 1095 hptep[1] &= ~HPTE_R_C; 1096 eieio(); 1097 hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 1098 if (!(rev[i].guest_rpte & HPTE_R_C)) { 1099 rev[i].guest_rpte |= HPTE_R_C; 1100 note_hpte_modification(kvm, &rev[i]); 1101 } 1102 ret = 1; 1103 } 1104 hptep[0] &= ~HPTE_V_HVLOCK; 1105 } while ((i = j) != head); 1106 1107 unlock_rmap(rmapp); 1108 return ret; 1109 } 1110 1111 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, 1112 struct kvm_memory_slot *memslot, 1113 unsigned long *map) 1114 { 1115 unsigned long gfn; 1116 1117 if (!vpa->dirty || !vpa->pinned_addr) 1118 return; 1119 gfn = vpa->gpa >> PAGE_SHIFT; 1120 if (gfn < memslot->base_gfn || 1121 gfn >= memslot->base_gfn + memslot->npages) 1122 return; 1123 1124 vpa->dirty = false; 1125 if (map) 1126 __set_bit_le(gfn - memslot->base_gfn, map); 1127 } 1128 1129 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, 1130 unsigned long *map) 1131 { 1132 unsigned long i; 1133 unsigned long *rmapp; 1134 struct kvm_vcpu *vcpu; 1135 1136 preempt_disable(); 1137 rmapp = memslot->arch.rmap; 1138 for (i = 0; i < memslot->npages; ++i) { 1139 if (kvm_test_clear_dirty(kvm, rmapp) && map) 1140 __set_bit_le(i, map); 1141 ++rmapp; 1142 } 1143 1144 /* Harvest dirty bits from VPA and DTL updates */ 1145 /* Note: we never modify the SLB shadow buffer areas */ 1146 kvm_for_each_vcpu(i, vcpu, kvm) { 1147 spin_lock(&vcpu->arch.vpa_update_lock); 1148 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map); 1149 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map); 1150 spin_unlock(&vcpu->arch.vpa_update_lock); 1151 } 1152 preempt_enable(); 1153 return 0; 1154 } 1155 1156 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, 1157 unsigned long *nb_ret) 1158 { 1159 struct kvm_memory_slot *memslot; 1160 unsigned long gfn = gpa >> PAGE_SHIFT; 1161 struct page *page, *pages[1]; 1162 int npages; 1163 unsigned long hva, offset; 1164 unsigned long pa; 1165 unsigned long *physp; 1166 int srcu_idx; 1167 1168 srcu_idx = srcu_read_lock(&kvm->srcu); 1169 memslot = gfn_to_memslot(kvm, gfn); 1170 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 1171 goto err; 1172 if (!kvm->arch.using_mmu_notifiers) { 1173 physp = memslot->arch.slot_phys; 1174 if (!physp) 1175 goto err; 1176 physp += gfn - memslot->base_gfn; 1177 pa = *physp; 1178 if (!pa) { 1179 if (kvmppc_get_guest_page(kvm, gfn, memslot, 1180 PAGE_SIZE) < 0) 1181 goto err; 1182 pa = *physp; 1183 } 1184 page = pfn_to_page(pa >> PAGE_SHIFT); 1185 get_page(page); 1186 } else { 1187 hva = gfn_to_hva_memslot(memslot, gfn); 1188 npages = get_user_pages_fast(hva, 1, 1, pages); 1189 if (npages < 1) 1190 goto err; 1191 page = pages[0]; 1192 } 1193 srcu_read_unlock(&kvm->srcu, srcu_idx); 1194 1195 offset = gpa & (PAGE_SIZE - 1); 1196 if (nb_ret) 1197 *nb_ret = PAGE_SIZE - offset; 1198 return page_address(page) + offset; 1199 1200 err: 1201 srcu_read_unlock(&kvm->srcu, srcu_idx); 1202 return NULL; 1203 } 1204 1205 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa, 1206 bool dirty) 1207 { 1208 struct page *page = virt_to_page(va); 1209 struct kvm_memory_slot *memslot; 1210 unsigned long gfn; 1211 unsigned long *rmap; 1212 int srcu_idx; 1213 1214 put_page(page); 1215 1216 if (!dirty || !kvm->arch.using_mmu_notifiers) 1217 return; 1218 1219 /* We need to mark this page dirty in the rmap chain */ 1220 gfn = gpa >> PAGE_SHIFT; 1221 srcu_idx = srcu_read_lock(&kvm->srcu); 1222 memslot = gfn_to_memslot(kvm, gfn); 1223 if (memslot) { 1224 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 1225 lock_rmap(rmap); 1226 *rmap |= KVMPPC_RMAP_CHANGED; 1227 unlock_rmap(rmap); 1228 } 1229 srcu_read_unlock(&kvm->srcu, srcu_idx); 1230 } 1231 1232 /* 1233 * Functions for reading and writing the hash table via reads and 1234 * writes on a file descriptor. 1235 * 1236 * Reads return the guest view of the hash table, which has to be 1237 * pieced together from the real hash table and the guest_rpte 1238 * values in the revmap array. 1239 * 1240 * On writes, each HPTE written is considered in turn, and if it 1241 * is valid, it is written to the HPT as if an H_ENTER with the 1242 * exact flag set was done. When the invalid count is non-zero 1243 * in the header written to the stream, the kernel will make 1244 * sure that that many HPTEs are invalid, and invalidate them 1245 * if not. 1246 */ 1247 1248 struct kvm_htab_ctx { 1249 unsigned long index; 1250 unsigned long flags; 1251 struct kvm *kvm; 1252 int first_pass; 1253 }; 1254 1255 #define HPTE_SIZE (2 * sizeof(unsigned long)) 1256 1257 /* 1258 * Returns 1 if this HPT entry has been modified or has pending 1259 * R/C bit changes. 1260 */ 1261 static int hpte_dirty(struct revmap_entry *revp, unsigned long *hptp) 1262 { 1263 unsigned long rcbits_unset; 1264 1265 if (revp->guest_rpte & HPTE_GR_MODIFIED) 1266 return 1; 1267 1268 /* Also need to consider changes in reference and changed bits */ 1269 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1270 if ((hptp[0] & HPTE_V_VALID) && (hptp[1] & rcbits_unset)) 1271 return 1; 1272 1273 return 0; 1274 } 1275 1276 static long record_hpte(unsigned long flags, unsigned long *hptp, 1277 unsigned long *hpte, struct revmap_entry *revp, 1278 int want_valid, int first_pass) 1279 { 1280 unsigned long v, r; 1281 unsigned long rcbits_unset; 1282 int ok = 1; 1283 int valid, dirty; 1284 1285 /* Unmodified entries are uninteresting except on the first pass */ 1286 dirty = hpte_dirty(revp, hptp); 1287 if (!first_pass && !dirty) 1288 return 0; 1289 1290 valid = 0; 1291 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) { 1292 valid = 1; 1293 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && 1294 !(hptp[0] & HPTE_V_BOLTED)) 1295 valid = 0; 1296 } 1297 if (valid != want_valid) 1298 return 0; 1299 1300 v = r = 0; 1301 if (valid || dirty) { 1302 /* lock the HPTE so it's stable and read it */ 1303 preempt_disable(); 1304 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) 1305 cpu_relax(); 1306 v = hptp[0]; 1307 1308 /* re-evaluate valid and dirty from synchronized HPTE value */ 1309 valid = !!(v & HPTE_V_VALID); 1310 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); 1311 1312 /* Harvest R and C into guest view if necessary */ 1313 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1314 if (valid && (rcbits_unset & hptp[1])) { 1315 revp->guest_rpte |= (hptp[1] & (HPTE_R_R | HPTE_R_C)) | 1316 HPTE_GR_MODIFIED; 1317 dirty = 1; 1318 } 1319 1320 if (v & HPTE_V_ABSENT) { 1321 v &= ~HPTE_V_ABSENT; 1322 v |= HPTE_V_VALID; 1323 valid = 1; 1324 } 1325 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) 1326 valid = 0; 1327 1328 r = revp->guest_rpte; 1329 /* only clear modified if this is the right sort of entry */ 1330 if (valid == want_valid && dirty) { 1331 r &= ~HPTE_GR_MODIFIED; 1332 revp->guest_rpte = r; 1333 } 1334 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory"); 1335 hptp[0] &= ~HPTE_V_HVLOCK; 1336 preempt_enable(); 1337 if (!(valid == want_valid && (first_pass || dirty))) 1338 ok = 0; 1339 } 1340 hpte[0] = v; 1341 hpte[1] = r; 1342 return ok; 1343 } 1344 1345 static ssize_t kvm_htab_read(struct file *file, char __user *buf, 1346 size_t count, loff_t *ppos) 1347 { 1348 struct kvm_htab_ctx *ctx = file->private_data; 1349 struct kvm *kvm = ctx->kvm; 1350 struct kvm_get_htab_header hdr; 1351 unsigned long *hptp; 1352 struct revmap_entry *revp; 1353 unsigned long i, nb, nw; 1354 unsigned long __user *lbuf; 1355 struct kvm_get_htab_header __user *hptr; 1356 unsigned long flags; 1357 int first_pass; 1358 unsigned long hpte[2]; 1359 1360 if (!access_ok(VERIFY_WRITE, buf, count)) 1361 return -EFAULT; 1362 1363 first_pass = ctx->first_pass; 1364 flags = ctx->flags; 1365 1366 i = ctx->index; 1367 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1368 revp = kvm->arch.revmap + i; 1369 lbuf = (unsigned long __user *)buf; 1370 1371 nb = 0; 1372 while (nb + sizeof(hdr) + HPTE_SIZE < count) { 1373 /* Initialize header */ 1374 hptr = (struct kvm_get_htab_header __user *)buf; 1375 hdr.n_valid = 0; 1376 hdr.n_invalid = 0; 1377 nw = nb; 1378 nb += sizeof(hdr); 1379 lbuf = (unsigned long __user *)(buf + sizeof(hdr)); 1380 1381 /* Skip uninteresting entries, i.e. clean on not-first pass */ 1382 if (!first_pass) { 1383 while (i < kvm->arch.hpt_npte && 1384 !hpte_dirty(revp, hptp)) { 1385 ++i; 1386 hptp += 2; 1387 ++revp; 1388 } 1389 } 1390 hdr.index = i; 1391 1392 /* Grab a series of valid entries */ 1393 while (i < kvm->arch.hpt_npte && 1394 hdr.n_valid < 0xffff && 1395 nb + HPTE_SIZE < count && 1396 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) { 1397 /* valid entry, write it out */ 1398 ++hdr.n_valid; 1399 if (__put_user(hpte[0], lbuf) || 1400 __put_user(hpte[1], lbuf + 1)) 1401 return -EFAULT; 1402 nb += HPTE_SIZE; 1403 lbuf += 2; 1404 ++i; 1405 hptp += 2; 1406 ++revp; 1407 } 1408 /* Now skip invalid entries while we can */ 1409 while (i < kvm->arch.hpt_npte && 1410 hdr.n_invalid < 0xffff && 1411 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) { 1412 /* found an invalid entry */ 1413 ++hdr.n_invalid; 1414 ++i; 1415 hptp += 2; 1416 ++revp; 1417 } 1418 1419 if (hdr.n_valid || hdr.n_invalid) { 1420 /* write back the header */ 1421 if (__copy_to_user(hptr, &hdr, sizeof(hdr))) 1422 return -EFAULT; 1423 nw = nb; 1424 buf = (char __user *)lbuf; 1425 } else { 1426 nb = nw; 1427 } 1428 1429 /* Check if we've wrapped around the hash table */ 1430 if (i >= kvm->arch.hpt_npte) { 1431 i = 0; 1432 ctx->first_pass = 0; 1433 break; 1434 } 1435 } 1436 1437 ctx->index = i; 1438 1439 return nb; 1440 } 1441 1442 static ssize_t kvm_htab_write(struct file *file, const char __user *buf, 1443 size_t count, loff_t *ppos) 1444 { 1445 struct kvm_htab_ctx *ctx = file->private_data; 1446 struct kvm *kvm = ctx->kvm; 1447 struct kvm_get_htab_header hdr; 1448 unsigned long i, j; 1449 unsigned long v, r; 1450 unsigned long __user *lbuf; 1451 unsigned long *hptp; 1452 unsigned long tmp[2]; 1453 ssize_t nb; 1454 long int err, ret; 1455 int rma_setup; 1456 1457 if (!access_ok(VERIFY_READ, buf, count)) 1458 return -EFAULT; 1459 1460 /* lock out vcpus from running while we're doing this */ 1461 mutex_lock(&kvm->lock); 1462 rma_setup = kvm->arch.rma_setup_done; 1463 if (rma_setup) { 1464 kvm->arch.rma_setup_done = 0; /* temporarily */ 1465 /* order rma_setup_done vs. vcpus_running */ 1466 smp_mb(); 1467 if (atomic_read(&kvm->arch.vcpus_running)) { 1468 kvm->arch.rma_setup_done = 1; 1469 mutex_unlock(&kvm->lock); 1470 return -EBUSY; 1471 } 1472 } 1473 1474 err = 0; 1475 for (nb = 0; nb + sizeof(hdr) <= count; ) { 1476 err = -EFAULT; 1477 if (__copy_from_user(&hdr, buf, sizeof(hdr))) 1478 break; 1479 1480 err = 0; 1481 if (nb + hdr.n_valid * HPTE_SIZE > count) 1482 break; 1483 1484 nb += sizeof(hdr); 1485 buf += sizeof(hdr); 1486 1487 err = -EINVAL; 1488 i = hdr.index; 1489 if (i >= kvm->arch.hpt_npte || 1490 i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte) 1491 break; 1492 1493 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1494 lbuf = (unsigned long __user *)buf; 1495 for (j = 0; j < hdr.n_valid; ++j) { 1496 err = -EFAULT; 1497 if (__get_user(v, lbuf) || __get_user(r, lbuf + 1)) 1498 goto out; 1499 err = -EINVAL; 1500 if (!(v & HPTE_V_VALID)) 1501 goto out; 1502 lbuf += 2; 1503 nb += HPTE_SIZE; 1504 1505 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) 1506 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1507 err = -EIO; 1508 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r, 1509 tmp); 1510 if (ret != H_SUCCESS) { 1511 pr_err("kvm_htab_write ret %ld i=%ld v=%lx " 1512 "r=%lx\n", ret, i, v, r); 1513 goto out; 1514 } 1515 if (!rma_setup && is_vrma_hpte(v)) { 1516 unsigned long psize = hpte_page_size(v, r); 1517 unsigned long senc = slb_pgsize_encoding(psize); 1518 unsigned long lpcr; 1519 1520 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T | 1521 (VRMA_VSID << SLB_VSID_SHIFT_1T); 1522 lpcr = senc << (LPCR_VRMASD_SH - 4); 1523 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD); 1524 rma_setup = 1; 1525 } 1526 ++i; 1527 hptp += 2; 1528 } 1529 1530 for (j = 0; j < hdr.n_invalid; ++j) { 1531 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) 1532 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1533 ++i; 1534 hptp += 2; 1535 } 1536 err = 0; 1537 } 1538 1539 out: 1540 /* Order HPTE updates vs. rma_setup_done */ 1541 smp_wmb(); 1542 kvm->arch.rma_setup_done = rma_setup; 1543 mutex_unlock(&kvm->lock); 1544 1545 if (err) 1546 return err; 1547 return nb; 1548 } 1549 1550 static int kvm_htab_release(struct inode *inode, struct file *filp) 1551 { 1552 struct kvm_htab_ctx *ctx = filp->private_data; 1553 1554 filp->private_data = NULL; 1555 if (!(ctx->flags & KVM_GET_HTAB_WRITE)) 1556 atomic_dec(&ctx->kvm->arch.hpte_mod_interest); 1557 kvm_put_kvm(ctx->kvm); 1558 kfree(ctx); 1559 return 0; 1560 } 1561 1562 static const struct file_operations kvm_htab_fops = { 1563 .read = kvm_htab_read, 1564 .write = kvm_htab_write, 1565 .llseek = default_llseek, 1566 .release = kvm_htab_release, 1567 }; 1568 1569 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf) 1570 { 1571 int ret; 1572 struct kvm_htab_ctx *ctx; 1573 int rwflag; 1574 1575 /* reject flags we don't recognize */ 1576 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE)) 1577 return -EINVAL; 1578 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 1579 if (!ctx) 1580 return -ENOMEM; 1581 kvm_get_kvm(kvm); 1582 ctx->kvm = kvm; 1583 ctx->index = ghf->start_index; 1584 ctx->flags = ghf->flags; 1585 ctx->first_pass = 1; 1586 1587 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY; 1588 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC); 1589 if (ret < 0) { 1590 kvm_put_kvm(kvm); 1591 return ret; 1592 } 1593 1594 if (rwflag == O_RDONLY) { 1595 mutex_lock(&kvm->slots_lock); 1596 atomic_inc(&kvm->arch.hpte_mod_interest); 1597 /* make sure kvmppc_do_h_enter etc. see the increment */ 1598 synchronize_srcu_expedited(&kvm->srcu); 1599 mutex_unlock(&kvm->slots_lock); 1600 } 1601 1602 return ret; 1603 } 1604 1605 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) 1606 { 1607 struct kvmppc_mmu *mmu = &vcpu->arch.mmu; 1608 1609 if (cpu_has_feature(CPU_FTR_ARCH_206)) 1610 vcpu->arch.slb_nr = 32; /* POWER7 */ 1611 else 1612 vcpu->arch.slb_nr = 64; 1613 1614 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate; 1615 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr; 1616 1617 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; 1618 } 1619