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 /* Find the HPTE in the hash table */ 473 index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, 474 HPTE_V_VALID | HPTE_V_ABSENT); 475 if (index < 0) 476 return -ENOENT; 477 hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); 478 v = hptep[0] & ~HPTE_V_HVLOCK; 479 gr = kvm->arch.revmap[index].guest_rpte; 480 481 /* Unlock the HPTE */ 482 asm volatile("lwsync" : : : "memory"); 483 hptep[0] = v; 484 485 gpte->eaddr = eaddr; 486 gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff); 487 488 /* Get PP bits and key for permission check */ 489 pp = gr & (HPTE_R_PP0 | HPTE_R_PP); 490 key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS; 491 key &= slb_v; 492 493 /* Calculate permissions */ 494 gpte->may_read = hpte_read_permission(pp, key); 495 gpte->may_write = hpte_write_permission(pp, key); 496 gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G)); 497 498 /* Storage key permission check for POWER7 */ 499 if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) { 500 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr); 501 if (amrfield & 1) 502 gpte->may_read = 0; 503 if (amrfield & 2) 504 gpte->may_write = 0; 505 } 506 507 /* Get the guest physical address */ 508 gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr); 509 return 0; 510 } 511 512 /* 513 * Quick test for whether an instruction is a load or a store. 514 * If the instruction is a load or a store, then this will indicate 515 * which it is, at least on server processors. (Embedded processors 516 * have some external PID instructions that don't follow the rule 517 * embodied here.) If the instruction isn't a load or store, then 518 * this doesn't return anything useful. 519 */ 520 static int instruction_is_store(unsigned int instr) 521 { 522 unsigned int mask; 523 524 mask = 0x10000000; 525 if ((instr & 0xfc000000) == 0x7c000000) 526 mask = 0x100; /* major opcode 31 */ 527 return (instr & mask) != 0; 528 } 529 530 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, 531 unsigned long gpa, gva_t ea, int is_store) 532 { 533 int ret; 534 u32 last_inst; 535 unsigned long srr0 = kvmppc_get_pc(vcpu); 536 537 /* We try to load the last instruction. We don't let 538 * emulate_instruction do it as it doesn't check what 539 * kvmppc_ld returns. 540 * If we fail, we just return to the guest and try executing it again. 541 */ 542 if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) { 543 ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false); 544 if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED) 545 return RESUME_GUEST; 546 vcpu->arch.last_inst = last_inst; 547 } 548 549 /* 550 * WARNING: We do not know for sure whether the instruction we just 551 * read from memory is the same that caused the fault in the first 552 * place. If the instruction we read is neither an load or a store, 553 * then it can't access memory, so we don't need to worry about 554 * enforcing access permissions. So, assuming it is a load or 555 * store, we just check that its direction (load or store) is 556 * consistent with the original fault, since that's what we 557 * checked the access permissions against. If there is a mismatch 558 * we just return and retry the instruction. 559 */ 560 561 if (instruction_is_store(vcpu->arch.last_inst) != !!is_store) 562 return RESUME_GUEST; 563 564 /* 565 * Emulated accesses are emulated by looking at the hash for 566 * translation once, then performing the access later. The 567 * translation could be invalidated in the meantime in which 568 * point performing the subsequent memory access on the old 569 * physical address could possibly be a security hole for the 570 * guest (but not the host). 571 * 572 * This is less of an issue for MMIO stores since they aren't 573 * globally visible. It could be an issue for MMIO loads to 574 * a certain extent but we'll ignore it for now. 575 */ 576 577 vcpu->arch.paddr_accessed = gpa; 578 vcpu->arch.vaddr_accessed = ea; 579 return kvmppc_emulate_mmio(run, vcpu); 580 } 581 582 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 583 unsigned long ea, unsigned long dsisr) 584 { 585 struct kvm *kvm = vcpu->kvm; 586 unsigned long *hptep, hpte[3], r; 587 unsigned long mmu_seq, psize, pte_size; 588 unsigned long gpa, gfn, hva, pfn; 589 struct kvm_memory_slot *memslot; 590 unsigned long *rmap; 591 struct revmap_entry *rev; 592 struct page *page, *pages[1]; 593 long index, ret, npages; 594 unsigned long is_io; 595 unsigned int writing, write_ok; 596 struct vm_area_struct *vma; 597 unsigned long rcbits; 598 599 /* 600 * Real-mode code has already searched the HPT and found the 601 * entry we're interested in. Lock the entry and check that 602 * it hasn't changed. If it has, just return and re-execute the 603 * instruction. 604 */ 605 if (ea != vcpu->arch.pgfault_addr) 606 return RESUME_GUEST; 607 index = vcpu->arch.pgfault_index; 608 hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); 609 rev = &kvm->arch.revmap[index]; 610 preempt_disable(); 611 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 612 cpu_relax(); 613 hpte[0] = hptep[0] & ~HPTE_V_HVLOCK; 614 hpte[1] = hptep[1]; 615 hpte[2] = r = rev->guest_rpte; 616 asm volatile("lwsync" : : : "memory"); 617 hptep[0] = hpte[0]; 618 preempt_enable(); 619 620 if (hpte[0] != vcpu->arch.pgfault_hpte[0] || 621 hpte[1] != vcpu->arch.pgfault_hpte[1]) 622 return RESUME_GUEST; 623 624 /* Translate the logical address and get the page */ 625 psize = hpte_page_size(hpte[0], r); 626 gpa = (r & HPTE_R_RPN & ~(psize - 1)) | (ea & (psize - 1)); 627 gfn = gpa >> PAGE_SHIFT; 628 memslot = gfn_to_memslot(kvm, gfn); 629 630 /* No memslot means it's an emulated MMIO region */ 631 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 632 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, 633 dsisr & DSISR_ISSTORE); 634 635 if (!kvm->arch.using_mmu_notifiers) 636 return -EFAULT; /* should never get here */ 637 638 /* used to check for invalidations in progress */ 639 mmu_seq = kvm->mmu_notifier_seq; 640 smp_rmb(); 641 642 is_io = 0; 643 pfn = 0; 644 page = NULL; 645 pte_size = PAGE_SIZE; 646 writing = (dsisr & DSISR_ISSTORE) != 0; 647 /* If writing != 0, then the HPTE must allow writing, if we get here */ 648 write_ok = writing; 649 hva = gfn_to_hva_memslot(memslot, gfn); 650 npages = get_user_pages_fast(hva, 1, writing, pages); 651 if (npages < 1) { 652 /* Check if it's an I/O mapping */ 653 down_read(¤t->mm->mmap_sem); 654 vma = find_vma(current->mm, hva); 655 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end && 656 (vma->vm_flags & VM_PFNMAP)) { 657 pfn = vma->vm_pgoff + 658 ((hva - vma->vm_start) >> PAGE_SHIFT); 659 pte_size = psize; 660 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot)); 661 write_ok = vma->vm_flags & VM_WRITE; 662 } 663 up_read(¤t->mm->mmap_sem); 664 if (!pfn) 665 return -EFAULT; 666 } else { 667 page = pages[0]; 668 if (PageHuge(page)) { 669 page = compound_head(page); 670 pte_size <<= compound_order(page); 671 } 672 /* if the guest wants write access, see if that is OK */ 673 if (!writing && hpte_is_writable(r)) { 674 unsigned int hugepage_shift; 675 pte_t *ptep, pte; 676 677 /* 678 * We need to protect against page table destruction 679 * while looking up and updating the pte. 680 */ 681 rcu_read_lock_sched(); 682 ptep = find_linux_pte_or_hugepte(current->mm->pgd, 683 hva, &hugepage_shift); 684 if (ptep) { 685 pte = kvmppc_read_update_linux_pte(ptep, 1, 686 hugepage_shift); 687 if (pte_write(pte)) 688 write_ok = 1; 689 } 690 rcu_read_unlock_sched(); 691 } 692 pfn = page_to_pfn(page); 693 } 694 695 ret = -EFAULT; 696 if (psize > pte_size) 697 goto out_put; 698 699 /* Check WIMG vs. the actual page we're accessing */ 700 if (!hpte_cache_flags_ok(r, is_io)) { 701 if (is_io) 702 return -EFAULT; 703 /* 704 * Allow guest to map emulated device memory as 705 * uncacheable, but actually make it cacheable. 706 */ 707 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M; 708 } 709 710 /* Set the HPTE to point to pfn */ 711 r = (r & ~(HPTE_R_PP0 - pte_size)) | (pfn << PAGE_SHIFT); 712 if (hpte_is_writable(r) && !write_ok) 713 r = hpte_make_readonly(r); 714 ret = RESUME_GUEST; 715 preempt_disable(); 716 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 717 cpu_relax(); 718 if ((hptep[0] & ~HPTE_V_HVLOCK) != hpte[0] || hptep[1] != hpte[1] || 719 rev->guest_rpte != hpte[2]) 720 /* HPTE has been changed under us; let the guest retry */ 721 goto out_unlock; 722 hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 723 724 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 725 lock_rmap(rmap); 726 727 /* Check if we might have been invalidated; let the guest retry if so */ 728 ret = RESUME_GUEST; 729 if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) { 730 unlock_rmap(rmap); 731 goto out_unlock; 732 } 733 734 /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */ 735 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT; 736 r &= rcbits | ~(HPTE_R_R | HPTE_R_C); 737 738 if (hptep[0] & HPTE_V_VALID) { 739 /* HPTE was previously valid, so we need to invalidate it */ 740 unlock_rmap(rmap); 741 hptep[0] |= HPTE_V_ABSENT; 742 kvmppc_invalidate_hpte(kvm, hptep, index); 743 /* don't lose previous R and C bits */ 744 r |= hptep[1] & (HPTE_R_R | HPTE_R_C); 745 } else { 746 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0); 747 } 748 749 hptep[1] = r; 750 eieio(); 751 hptep[0] = hpte[0]; 752 asm volatile("ptesync" : : : "memory"); 753 preempt_enable(); 754 if (page && hpte_is_writable(r)) 755 SetPageDirty(page); 756 757 out_put: 758 if (page) { 759 /* 760 * We drop pages[0] here, not page because page might 761 * have been set to the head page of a compound, but 762 * we have to drop the reference on the correct tail 763 * page to match the get inside gup() 764 */ 765 put_page(pages[0]); 766 } 767 return ret; 768 769 out_unlock: 770 hptep[0] &= ~HPTE_V_HVLOCK; 771 preempt_enable(); 772 goto out_put; 773 } 774 775 static void kvmppc_rmap_reset(struct kvm *kvm) 776 { 777 struct kvm_memslots *slots; 778 struct kvm_memory_slot *memslot; 779 int srcu_idx; 780 781 srcu_idx = srcu_read_lock(&kvm->srcu); 782 slots = kvm->memslots; 783 kvm_for_each_memslot(memslot, slots) { 784 /* 785 * This assumes it is acceptable to lose reference and 786 * change bits across a reset. 787 */ 788 memset(memslot->arch.rmap, 0, 789 memslot->npages * sizeof(*memslot->arch.rmap)); 790 } 791 srcu_read_unlock(&kvm->srcu, srcu_idx); 792 } 793 794 static int kvm_handle_hva_range(struct kvm *kvm, 795 unsigned long start, 796 unsigned long end, 797 int (*handler)(struct kvm *kvm, 798 unsigned long *rmapp, 799 unsigned long gfn)) 800 { 801 int ret; 802 int retval = 0; 803 struct kvm_memslots *slots; 804 struct kvm_memory_slot *memslot; 805 806 slots = kvm_memslots(kvm); 807 kvm_for_each_memslot(memslot, slots) { 808 unsigned long hva_start, hva_end; 809 gfn_t gfn, gfn_end; 810 811 hva_start = max(start, memslot->userspace_addr); 812 hva_end = min(end, memslot->userspace_addr + 813 (memslot->npages << PAGE_SHIFT)); 814 if (hva_start >= hva_end) 815 continue; 816 /* 817 * {gfn(page) | page intersects with [hva_start, hva_end)} = 818 * {gfn, gfn+1, ..., gfn_end-1}. 819 */ 820 gfn = hva_to_gfn_memslot(hva_start, memslot); 821 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); 822 823 for (; gfn < gfn_end; ++gfn) { 824 gfn_t gfn_offset = gfn - memslot->base_gfn; 825 826 ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn); 827 retval |= ret; 828 } 829 } 830 831 return retval; 832 } 833 834 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, 835 int (*handler)(struct kvm *kvm, unsigned long *rmapp, 836 unsigned long gfn)) 837 { 838 return kvm_handle_hva_range(kvm, hva, hva + 1, handler); 839 } 840 841 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, 842 unsigned long gfn) 843 { 844 struct revmap_entry *rev = kvm->arch.revmap; 845 unsigned long h, i, j; 846 unsigned long *hptep; 847 unsigned long ptel, psize, rcbits; 848 849 for (;;) { 850 lock_rmap(rmapp); 851 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 852 unlock_rmap(rmapp); 853 break; 854 } 855 856 /* 857 * To avoid an ABBA deadlock with the HPTE lock bit, 858 * we can't spin on the HPTE lock while holding the 859 * rmap chain lock. 860 */ 861 i = *rmapp & KVMPPC_RMAP_INDEX; 862 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 863 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 864 /* unlock rmap before spinning on the HPTE lock */ 865 unlock_rmap(rmapp); 866 while (hptep[0] & HPTE_V_HVLOCK) 867 cpu_relax(); 868 continue; 869 } 870 j = rev[i].forw; 871 if (j == i) { 872 /* chain is now empty */ 873 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX); 874 } else { 875 /* remove i from chain */ 876 h = rev[i].back; 877 rev[h].forw = j; 878 rev[j].back = h; 879 rev[i].forw = rev[i].back = i; 880 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j; 881 } 882 883 /* Now check and modify the HPTE */ 884 ptel = rev[i].guest_rpte; 885 psize = hpte_page_size(hptep[0], ptel); 886 if ((hptep[0] & HPTE_V_VALID) && 887 hpte_rpn(ptel, psize) == gfn) { 888 if (kvm->arch.using_mmu_notifiers) 889 hptep[0] |= HPTE_V_ABSENT; 890 kvmppc_invalidate_hpte(kvm, hptep, i); 891 /* Harvest R and C */ 892 rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C); 893 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT; 894 if (rcbits & ~rev[i].guest_rpte) { 895 rev[i].guest_rpte = ptel | rcbits; 896 note_hpte_modification(kvm, &rev[i]); 897 } 898 } 899 unlock_rmap(rmapp); 900 hptep[0] &= ~HPTE_V_HVLOCK; 901 } 902 return 0; 903 } 904 905 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva) 906 { 907 if (kvm->arch.using_mmu_notifiers) 908 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 909 return 0; 910 } 911 912 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end) 913 { 914 if (kvm->arch.using_mmu_notifiers) 915 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp); 916 return 0; 917 } 918 919 void kvmppc_core_flush_memslot_hv(struct kvm *kvm, 920 struct kvm_memory_slot *memslot) 921 { 922 unsigned long *rmapp; 923 unsigned long gfn; 924 unsigned long n; 925 926 rmapp = memslot->arch.rmap; 927 gfn = memslot->base_gfn; 928 for (n = memslot->npages; n; --n) { 929 /* 930 * Testing the present bit without locking is OK because 931 * the memslot has been marked invalid already, and hence 932 * no new HPTEs referencing this page can be created, 933 * thus the present bit can't go from 0 to 1. 934 */ 935 if (*rmapp & KVMPPC_RMAP_PRESENT) 936 kvm_unmap_rmapp(kvm, rmapp, gfn); 937 ++rmapp; 938 ++gfn; 939 } 940 } 941 942 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 943 unsigned long gfn) 944 { 945 struct revmap_entry *rev = kvm->arch.revmap; 946 unsigned long head, i, j; 947 unsigned long *hptep; 948 int ret = 0; 949 950 retry: 951 lock_rmap(rmapp); 952 if (*rmapp & KVMPPC_RMAP_REFERENCED) { 953 *rmapp &= ~KVMPPC_RMAP_REFERENCED; 954 ret = 1; 955 } 956 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 957 unlock_rmap(rmapp); 958 return ret; 959 } 960 961 i = head = *rmapp & KVMPPC_RMAP_INDEX; 962 do { 963 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 964 j = rev[i].forw; 965 966 /* If this HPTE isn't referenced, ignore it */ 967 if (!(hptep[1] & HPTE_R_R)) 968 continue; 969 970 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 971 /* unlock rmap before spinning on the HPTE lock */ 972 unlock_rmap(rmapp); 973 while (hptep[0] & HPTE_V_HVLOCK) 974 cpu_relax(); 975 goto retry; 976 } 977 978 /* Now check and modify the HPTE */ 979 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) { 980 kvmppc_clear_ref_hpte(kvm, hptep, i); 981 if (!(rev[i].guest_rpte & HPTE_R_R)) { 982 rev[i].guest_rpte |= HPTE_R_R; 983 note_hpte_modification(kvm, &rev[i]); 984 } 985 ret = 1; 986 } 987 hptep[0] &= ~HPTE_V_HVLOCK; 988 } while ((i = j) != head); 989 990 unlock_rmap(rmapp); 991 return ret; 992 } 993 994 int kvm_age_hva_hv(struct kvm *kvm, unsigned long hva) 995 { 996 if (!kvm->arch.using_mmu_notifiers) 997 return 0; 998 return kvm_handle_hva(kvm, hva, kvm_age_rmapp); 999 } 1000 1001 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 1002 unsigned long gfn) 1003 { 1004 struct revmap_entry *rev = kvm->arch.revmap; 1005 unsigned long head, i, j; 1006 unsigned long *hp; 1007 int ret = 1; 1008 1009 if (*rmapp & KVMPPC_RMAP_REFERENCED) 1010 return 1; 1011 1012 lock_rmap(rmapp); 1013 if (*rmapp & KVMPPC_RMAP_REFERENCED) 1014 goto out; 1015 1016 if (*rmapp & KVMPPC_RMAP_PRESENT) { 1017 i = head = *rmapp & KVMPPC_RMAP_INDEX; 1018 do { 1019 hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4)); 1020 j = rev[i].forw; 1021 if (hp[1] & HPTE_R_R) 1022 goto out; 1023 } while ((i = j) != head); 1024 } 1025 ret = 0; 1026 1027 out: 1028 unlock_rmap(rmapp); 1029 return ret; 1030 } 1031 1032 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva) 1033 { 1034 if (!kvm->arch.using_mmu_notifiers) 1035 return 0; 1036 return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp); 1037 } 1038 1039 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte) 1040 { 1041 if (!kvm->arch.using_mmu_notifiers) 1042 return; 1043 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 1044 } 1045 1046 static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) 1047 { 1048 struct revmap_entry *rev = kvm->arch.revmap; 1049 unsigned long head, i, j; 1050 unsigned long *hptep; 1051 int ret = 0; 1052 1053 retry: 1054 lock_rmap(rmapp); 1055 if (*rmapp & KVMPPC_RMAP_CHANGED) { 1056 *rmapp &= ~KVMPPC_RMAP_CHANGED; 1057 ret = 1; 1058 } 1059 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 1060 unlock_rmap(rmapp); 1061 return ret; 1062 } 1063 1064 i = head = *rmapp & KVMPPC_RMAP_INDEX; 1065 do { 1066 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 1067 j = rev[i].forw; 1068 1069 if (!(hptep[1] & HPTE_R_C)) 1070 continue; 1071 1072 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 1073 /* unlock rmap before spinning on the HPTE lock */ 1074 unlock_rmap(rmapp); 1075 while (hptep[0] & HPTE_V_HVLOCK) 1076 cpu_relax(); 1077 goto retry; 1078 } 1079 1080 /* Now check and modify the HPTE */ 1081 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) { 1082 /* need to make it temporarily absent to clear C */ 1083 hptep[0] |= HPTE_V_ABSENT; 1084 kvmppc_invalidate_hpte(kvm, hptep, i); 1085 hptep[1] &= ~HPTE_R_C; 1086 eieio(); 1087 hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 1088 if (!(rev[i].guest_rpte & HPTE_R_C)) { 1089 rev[i].guest_rpte |= HPTE_R_C; 1090 note_hpte_modification(kvm, &rev[i]); 1091 } 1092 ret = 1; 1093 } 1094 hptep[0] &= ~HPTE_V_HVLOCK; 1095 } while ((i = j) != head); 1096 1097 unlock_rmap(rmapp); 1098 return ret; 1099 } 1100 1101 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, 1102 struct kvm_memory_slot *memslot, 1103 unsigned long *map) 1104 { 1105 unsigned long gfn; 1106 1107 if (!vpa->dirty || !vpa->pinned_addr) 1108 return; 1109 gfn = vpa->gpa >> PAGE_SHIFT; 1110 if (gfn < memslot->base_gfn || 1111 gfn >= memslot->base_gfn + memslot->npages) 1112 return; 1113 1114 vpa->dirty = false; 1115 if (map) 1116 __set_bit_le(gfn - memslot->base_gfn, map); 1117 } 1118 1119 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, 1120 unsigned long *map) 1121 { 1122 unsigned long i; 1123 unsigned long *rmapp; 1124 struct kvm_vcpu *vcpu; 1125 1126 preempt_disable(); 1127 rmapp = memslot->arch.rmap; 1128 for (i = 0; i < memslot->npages; ++i) { 1129 if (kvm_test_clear_dirty(kvm, rmapp) && map) 1130 __set_bit_le(i, map); 1131 ++rmapp; 1132 } 1133 1134 /* Harvest dirty bits from VPA and DTL updates */ 1135 /* Note: we never modify the SLB shadow buffer areas */ 1136 kvm_for_each_vcpu(i, vcpu, kvm) { 1137 spin_lock(&vcpu->arch.vpa_update_lock); 1138 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map); 1139 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map); 1140 spin_unlock(&vcpu->arch.vpa_update_lock); 1141 } 1142 preempt_enable(); 1143 return 0; 1144 } 1145 1146 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, 1147 unsigned long *nb_ret) 1148 { 1149 struct kvm_memory_slot *memslot; 1150 unsigned long gfn = gpa >> PAGE_SHIFT; 1151 struct page *page, *pages[1]; 1152 int npages; 1153 unsigned long hva, offset; 1154 unsigned long pa; 1155 unsigned long *physp; 1156 int srcu_idx; 1157 1158 srcu_idx = srcu_read_lock(&kvm->srcu); 1159 memslot = gfn_to_memslot(kvm, gfn); 1160 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 1161 goto err; 1162 if (!kvm->arch.using_mmu_notifiers) { 1163 physp = memslot->arch.slot_phys; 1164 if (!physp) 1165 goto err; 1166 physp += gfn - memslot->base_gfn; 1167 pa = *physp; 1168 if (!pa) { 1169 if (kvmppc_get_guest_page(kvm, gfn, memslot, 1170 PAGE_SIZE) < 0) 1171 goto err; 1172 pa = *physp; 1173 } 1174 page = pfn_to_page(pa >> PAGE_SHIFT); 1175 get_page(page); 1176 } else { 1177 hva = gfn_to_hva_memslot(memslot, gfn); 1178 npages = get_user_pages_fast(hva, 1, 1, pages); 1179 if (npages < 1) 1180 goto err; 1181 page = pages[0]; 1182 } 1183 srcu_read_unlock(&kvm->srcu, srcu_idx); 1184 1185 offset = gpa & (PAGE_SIZE - 1); 1186 if (nb_ret) 1187 *nb_ret = PAGE_SIZE - offset; 1188 return page_address(page) + offset; 1189 1190 err: 1191 srcu_read_unlock(&kvm->srcu, srcu_idx); 1192 return NULL; 1193 } 1194 1195 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa, 1196 bool dirty) 1197 { 1198 struct page *page = virt_to_page(va); 1199 struct kvm_memory_slot *memslot; 1200 unsigned long gfn; 1201 unsigned long *rmap; 1202 int srcu_idx; 1203 1204 put_page(page); 1205 1206 if (!dirty || !kvm->arch.using_mmu_notifiers) 1207 return; 1208 1209 /* We need to mark this page dirty in the rmap chain */ 1210 gfn = gpa >> PAGE_SHIFT; 1211 srcu_idx = srcu_read_lock(&kvm->srcu); 1212 memslot = gfn_to_memslot(kvm, gfn); 1213 if (memslot) { 1214 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 1215 lock_rmap(rmap); 1216 *rmap |= KVMPPC_RMAP_CHANGED; 1217 unlock_rmap(rmap); 1218 } 1219 srcu_read_unlock(&kvm->srcu, srcu_idx); 1220 } 1221 1222 /* 1223 * Functions for reading and writing the hash table via reads and 1224 * writes on a file descriptor. 1225 * 1226 * Reads return the guest view of the hash table, which has to be 1227 * pieced together from the real hash table and the guest_rpte 1228 * values in the revmap array. 1229 * 1230 * On writes, each HPTE written is considered in turn, and if it 1231 * is valid, it is written to the HPT as if an H_ENTER with the 1232 * exact flag set was done. When the invalid count is non-zero 1233 * in the header written to the stream, the kernel will make 1234 * sure that that many HPTEs are invalid, and invalidate them 1235 * if not. 1236 */ 1237 1238 struct kvm_htab_ctx { 1239 unsigned long index; 1240 unsigned long flags; 1241 struct kvm *kvm; 1242 int first_pass; 1243 }; 1244 1245 #define HPTE_SIZE (2 * sizeof(unsigned long)) 1246 1247 /* 1248 * Returns 1 if this HPT entry has been modified or has pending 1249 * R/C bit changes. 1250 */ 1251 static int hpte_dirty(struct revmap_entry *revp, unsigned long *hptp) 1252 { 1253 unsigned long rcbits_unset; 1254 1255 if (revp->guest_rpte & HPTE_GR_MODIFIED) 1256 return 1; 1257 1258 /* Also need to consider changes in reference and changed bits */ 1259 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1260 if ((hptp[0] & HPTE_V_VALID) && (hptp[1] & rcbits_unset)) 1261 return 1; 1262 1263 return 0; 1264 } 1265 1266 static long record_hpte(unsigned long flags, unsigned long *hptp, 1267 unsigned long *hpte, struct revmap_entry *revp, 1268 int want_valid, int first_pass) 1269 { 1270 unsigned long v, r; 1271 unsigned long rcbits_unset; 1272 int ok = 1; 1273 int valid, dirty; 1274 1275 /* Unmodified entries are uninteresting except on the first pass */ 1276 dirty = hpte_dirty(revp, hptp); 1277 if (!first_pass && !dirty) 1278 return 0; 1279 1280 valid = 0; 1281 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) { 1282 valid = 1; 1283 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && 1284 !(hptp[0] & HPTE_V_BOLTED)) 1285 valid = 0; 1286 } 1287 if (valid != want_valid) 1288 return 0; 1289 1290 v = r = 0; 1291 if (valid || dirty) { 1292 /* lock the HPTE so it's stable and read it */ 1293 preempt_disable(); 1294 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) 1295 cpu_relax(); 1296 v = hptp[0]; 1297 1298 /* re-evaluate valid and dirty from synchronized HPTE value */ 1299 valid = !!(v & HPTE_V_VALID); 1300 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); 1301 1302 /* Harvest R and C into guest view if necessary */ 1303 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1304 if (valid && (rcbits_unset & hptp[1])) { 1305 revp->guest_rpte |= (hptp[1] & (HPTE_R_R | HPTE_R_C)) | 1306 HPTE_GR_MODIFIED; 1307 dirty = 1; 1308 } 1309 1310 if (v & HPTE_V_ABSENT) { 1311 v &= ~HPTE_V_ABSENT; 1312 v |= HPTE_V_VALID; 1313 valid = 1; 1314 } 1315 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) 1316 valid = 0; 1317 1318 r = revp->guest_rpte; 1319 /* only clear modified if this is the right sort of entry */ 1320 if (valid == want_valid && dirty) { 1321 r &= ~HPTE_GR_MODIFIED; 1322 revp->guest_rpte = r; 1323 } 1324 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory"); 1325 hptp[0] &= ~HPTE_V_HVLOCK; 1326 preempt_enable(); 1327 if (!(valid == want_valid && (first_pass || dirty))) 1328 ok = 0; 1329 } 1330 hpte[0] = v; 1331 hpte[1] = r; 1332 return ok; 1333 } 1334 1335 static ssize_t kvm_htab_read(struct file *file, char __user *buf, 1336 size_t count, loff_t *ppos) 1337 { 1338 struct kvm_htab_ctx *ctx = file->private_data; 1339 struct kvm *kvm = ctx->kvm; 1340 struct kvm_get_htab_header hdr; 1341 unsigned long *hptp; 1342 struct revmap_entry *revp; 1343 unsigned long i, nb, nw; 1344 unsigned long __user *lbuf; 1345 struct kvm_get_htab_header __user *hptr; 1346 unsigned long flags; 1347 int first_pass; 1348 unsigned long hpte[2]; 1349 1350 if (!access_ok(VERIFY_WRITE, buf, count)) 1351 return -EFAULT; 1352 1353 first_pass = ctx->first_pass; 1354 flags = ctx->flags; 1355 1356 i = ctx->index; 1357 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1358 revp = kvm->arch.revmap + i; 1359 lbuf = (unsigned long __user *)buf; 1360 1361 nb = 0; 1362 while (nb + sizeof(hdr) + HPTE_SIZE < count) { 1363 /* Initialize header */ 1364 hptr = (struct kvm_get_htab_header __user *)buf; 1365 hdr.n_valid = 0; 1366 hdr.n_invalid = 0; 1367 nw = nb; 1368 nb += sizeof(hdr); 1369 lbuf = (unsigned long __user *)(buf + sizeof(hdr)); 1370 1371 /* Skip uninteresting entries, i.e. clean on not-first pass */ 1372 if (!first_pass) { 1373 while (i < kvm->arch.hpt_npte && 1374 !hpte_dirty(revp, hptp)) { 1375 ++i; 1376 hptp += 2; 1377 ++revp; 1378 } 1379 } 1380 hdr.index = i; 1381 1382 /* Grab a series of valid entries */ 1383 while (i < kvm->arch.hpt_npte && 1384 hdr.n_valid < 0xffff && 1385 nb + HPTE_SIZE < count && 1386 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) { 1387 /* valid entry, write it out */ 1388 ++hdr.n_valid; 1389 if (__put_user(hpte[0], lbuf) || 1390 __put_user(hpte[1], lbuf + 1)) 1391 return -EFAULT; 1392 nb += HPTE_SIZE; 1393 lbuf += 2; 1394 ++i; 1395 hptp += 2; 1396 ++revp; 1397 } 1398 /* Now skip invalid entries while we can */ 1399 while (i < kvm->arch.hpt_npte && 1400 hdr.n_invalid < 0xffff && 1401 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) { 1402 /* found an invalid entry */ 1403 ++hdr.n_invalid; 1404 ++i; 1405 hptp += 2; 1406 ++revp; 1407 } 1408 1409 if (hdr.n_valid || hdr.n_invalid) { 1410 /* write back the header */ 1411 if (__copy_to_user(hptr, &hdr, sizeof(hdr))) 1412 return -EFAULT; 1413 nw = nb; 1414 buf = (char __user *)lbuf; 1415 } else { 1416 nb = nw; 1417 } 1418 1419 /* Check if we've wrapped around the hash table */ 1420 if (i >= kvm->arch.hpt_npte) { 1421 i = 0; 1422 ctx->first_pass = 0; 1423 break; 1424 } 1425 } 1426 1427 ctx->index = i; 1428 1429 return nb; 1430 } 1431 1432 static ssize_t kvm_htab_write(struct file *file, const char __user *buf, 1433 size_t count, loff_t *ppos) 1434 { 1435 struct kvm_htab_ctx *ctx = file->private_data; 1436 struct kvm *kvm = ctx->kvm; 1437 struct kvm_get_htab_header hdr; 1438 unsigned long i, j; 1439 unsigned long v, r; 1440 unsigned long __user *lbuf; 1441 unsigned long *hptp; 1442 unsigned long tmp[2]; 1443 ssize_t nb; 1444 long int err, ret; 1445 int rma_setup; 1446 1447 if (!access_ok(VERIFY_READ, buf, count)) 1448 return -EFAULT; 1449 1450 /* lock out vcpus from running while we're doing this */ 1451 mutex_lock(&kvm->lock); 1452 rma_setup = kvm->arch.rma_setup_done; 1453 if (rma_setup) { 1454 kvm->arch.rma_setup_done = 0; /* temporarily */ 1455 /* order rma_setup_done vs. vcpus_running */ 1456 smp_mb(); 1457 if (atomic_read(&kvm->arch.vcpus_running)) { 1458 kvm->arch.rma_setup_done = 1; 1459 mutex_unlock(&kvm->lock); 1460 return -EBUSY; 1461 } 1462 } 1463 1464 err = 0; 1465 for (nb = 0; nb + sizeof(hdr) <= count; ) { 1466 err = -EFAULT; 1467 if (__copy_from_user(&hdr, buf, sizeof(hdr))) 1468 break; 1469 1470 err = 0; 1471 if (nb + hdr.n_valid * HPTE_SIZE > count) 1472 break; 1473 1474 nb += sizeof(hdr); 1475 buf += sizeof(hdr); 1476 1477 err = -EINVAL; 1478 i = hdr.index; 1479 if (i >= kvm->arch.hpt_npte || 1480 i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte) 1481 break; 1482 1483 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1484 lbuf = (unsigned long __user *)buf; 1485 for (j = 0; j < hdr.n_valid; ++j) { 1486 err = -EFAULT; 1487 if (__get_user(v, lbuf) || __get_user(r, lbuf + 1)) 1488 goto out; 1489 err = -EINVAL; 1490 if (!(v & HPTE_V_VALID)) 1491 goto out; 1492 lbuf += 2; 1493 nb += HPTE_SIZE; 1494 1495 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) 1496 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1497 err = -EIO; 1498 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r, 1499 tmp); 1500 if (ret != H_SUCCESS) { 1501 pr_err("kvm_htab_write ret %ld i=%ld v=%lx " 1502 "r=%lx\n", ret, i, v, r); 1503 goto out; 1504 } 1505 if (!rma_setup && is_vrma_hpte(v)) { 1506 unsigned long psize = hpte_page_size(v, r); 1507 unsigned long senc = slb_pgsize_encoding(psize); 1508 unsigned long lpcr; 1509 1510 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T | 1511 (VRMA_VSID << SLB_VSID_SHIFT_1T); 1512 lpcr = senc << (LPCR_VRMASD_SH - 4); 1513 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD); 1514 rma_setup = 1; 1515 } 1516 ++i; 1517 hptp += 2; 1518 } 1519 1520 for (j = 0; j < hdr.n_invalid; ++j) { 1521 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) 1522 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1523 ++i; 1524 hptp += 2; 1525 } 1526 err = 0; 1527 } 1528 1529 out: 1530 /* Order HPTE updates vs. rma_setup_done */ 1531 smp_wmb(); 1532 kvm->arch.rma_setup_done = rma_setup; 1533 mutex_unlock(&kvm->lock); 1534 1535 if (err) 1536 return err; 1537 return nb; 1538 } 1539 1540 static int kvm_htab_release(struct inode *inode, struct file *filp) 1541 { 1542 struct kvm_htab_ctx *ctx = filp->private_data; 1543 1544 filp->private_data = NULL; 1545 if (!(ctx->flags & KVM_GET_HTAB_WRITE)) 1546 atomic_dec(&ctx->kvm->arch.hpte_mod_interest); 1547 kvm_put_kvm(ctx->kvm); 1548 kfree(ctx); 1549 return 0; 1550 } 1551 1552 static const struct file_operations kvm_htab_fops = { 1553 .read = kvm_htab_read, 1554 .write = kvm_htab_write, 1555 .llseek = default_llseek, 1556 .release = kvm_htab_release, 1557 }; 1558 1559 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf) 1560 { 1561 int ret; 1562 struct kvm_htab_ctx *ctx; 1563 int rwflag; 1564 1565 /* reject flags we don't recognize */ 1566 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE)) 1567 return -EINVAL; 1568 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 1569 if (!ctx) 1570 return -ENOMEM; 1571 kvm_get_kvm(kvm); 1572 ctx->kvm = kvm; 1573 ctx->index = ghf->start_index; 1574 ctx->flags = ghf->flags; 1575 ctx->first_pass = 1; 1576 1577 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY; 1578 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC); 1579 if (ret < 0) { 1580 kvm_put_kvm(kvm); 1581 return ret; 1582 } 1583 1584 if (rwflag == O_RDONLY) { 1585 mutex_lock(&kvm->slots_lock); 1586 atomic_inc(&kvm->arch.hpte_mod_interest); 1587 /* make sure kvmppc_do_h_enter etc. see the increment */ 1588 synchronize_srcu_expedited(&kvm->srcu); 1589 mutex_unlock(&kvm->slots_lock); 1590 } 1591 1592 return ret; 1593 } 1594 1595 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) 1596 { 1597 struct kvmppc_mmu *mmu = &vcpu->arch.mmu; 1598 1599 if (cpu_has_feature(CPU_FTR_ARCH_206)) 1600 vcpu->arch.slb_nr = 32; /* POWER7 */ 1601 else 1602 vcpu->arch.slb_nr = 64; 1603 1604 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate; 1605 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr; 1606 1607 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; 1608 } 1609