1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License, version 2, as 4 * published by the Free Software Foundation. 5 * 6 * This program is distributed in the hope that it will be useful, 7 * but WITHOUT ANY WARRANTY; without even the implied warranty of 8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 9 * GNU General Public License for more details. 10 * 11 * You should have received a copy of the GNU General Public License 12 * along with this program; if not, write to the Free Software 13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 14 * 15 * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> 16 */ 17 18 #include <linux/types.h> 19 #include <linux/string.h> 20 #include <linux/kvm.h> 21 #include <linux/kvm_host.h> 22 #include <linux/highmem.h> 23 #include <linux/gfp.h> 24 #include <linux/slab.h> 25 #include <linux/hugetlb.h> 26 #include <linux/vmalloc.h> 27 #include <linux/srcu.h> 28 #include <linux/anon_inodes.h> 29 #include <linux/file.h> 30 31 #include <asm/tlbflush.h> 32 #include <asm/kvm_ppc.h> 33 #include <asm/kvm_book3s.h> 34 #include <asm/mmu-hash64.h> 35 #include <asm/hvcall.h> 36 #include <asm/synch.h> 37 #include <asm/ppc-opcode.h> 38 #include <asm/cputable.h> 39 40 /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */ 41 #define MAX_LPID_970 63 42 43 /* Power architecture requires HPT is at least 256kB */ 44 #define PPC_MIN_HPT_ORDER 18 45 46 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 47 long pte_index, unsigned long pteh, 48 unsigned long ptel, unsigned long *pte_idx_ret); 49 static void kvmppc_rmap_reset(struct kvm *kvm); 50 51 long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp) 52 { 53 unsigned long hpt = 0; 54 struct revmap_entry *rev; 55 struct page *page = NULL; 56 long order = KVM_DEFAULT_HPT_ORDER; 57 58 if (htab_orderp) { 59 order = *htab_orderp; 60 if (order < PPC_MIN_HPT_ORDER) 61 order = PPC_MIN_HPT_ORDER; 62 } 63 64 kvm->arch.hpt_cma_alloc = 0; 65 page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT)); 66 if (page) { 67 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page)); 68 memset((void *)hpt, 0, (1 << order)); 69 kvm->arch.hpt_cma_alloc = 1; 70 } 71 72 /* Lastly try successively smaller sizes from the page allocator */ 73 while (!hpt && order > PPC_MIN_HPT_ORDER) { 74 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT| 75 __GFP_NOWARN, order - PAGE_SHIFT); 76 if (!hpt) 77 --order; 78 } 79 80 if (!hpt) 81 return -ENOMEM; 82 83 kvm->arch.hpt_virt = hpt; 84 kvm->arch.hpt_order = order; 85 /* HPTEs are 2**4 bytes long */ 86 kvm->arch.hpt_npte = 1ul << (order - 4); 87 /* 128 (2**7) bytes in each HPTEG */ 88 kvm->arch.hpt_mask = (1ul << (order - 7)) - 1; 89 90 /* Allocate reverse map array */ 91 rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte); 92 if (!rev) { 93 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n"); 94 goto out_freehpt; 95 } 96 kvm->arch.revmap = rev; 97 kvm->arch.sdr1 = __pa(hpt) | (order - 18); 98 99 pr_info("KVM guest htab at %lx (order %ld), LPID %x\n", 100 hpt, order, kvm->arch.lpid); 101 102 if (htab_orderp) 103 *htab_orderp = order; 104 return 0; 105 106 out_freehpt: 107 if (kvm->arch.hpt_cma_alloc) 108 kvm_release_hpt(page, 1 << (order - PAGE_SHIFT)); 109 else 110 free_pages(hpt, order - PAGE_SHIFT); 111 return -ENOMEM; 112 } 113 114 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp) 115 { 116 long err = -EBUSY; 117 long order; 118 119 mutex_lock(&kvm->lock); 120 if (kvm->arch.rma_setup_done) { 121 kvm->arch.rma_setup_done = 0; 122 /* order rma_setup_done vs. vcpus_running */ 123 smp_mb(); 124 if (atomic_read(&kvm->arch.vcpus_running)) { 125 kvm->arch.rma_setup_done = 1; 126 goto out; 127 } 128 } 129 if (kvm->arch.hpt_virt) { 130 order = kvm->arch.hpt_order; 131 /* Set the entire HPT to 0, i.e. invalid HPTEs */ 132 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order); 133 /* 134 * Reset all the reverse-mapping chains for all memslots 135 */ 136 kvmppc_rmap_reset(kvm); 137 /* Ensure that each vcpu will flush its TLB on next entry. */ 138 cpumask_setall(&kvm->arch.need_tlb_flush); 139 *htab_orderp = order; 140 err = 0; 141 } else { 142 err = kvmppc_alloc_hpt(kvm, htab_orderp); 143 order = *htab_orderp; 144 } 145 out: 146 mutex_unlock(&kvm->lock); 147 return err; 148 } 149 150 void kvmppc_free_hpt(struct kvm *kvm) 151 { 152 kvmppc_free_lpid(kvm->arch.lpid); 153 vfree(kvm->arch.revmap); 154 if (kvm->arch.hpt_cma_alloc) 155 kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt), 156 1 << (kvm->arch.hpt_order - PAGE_SHIFT)); 157 else 158 free_pages(kvm->arch.hpt_virt, 159 kvm->arch.hpt_order - PAGE_SHIFT); 160 } 161 162 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */ 163 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize) 164 { 165 return (pgsize > 0x1000) ? HPTE_V_LARGE : 0; 166 } 167 168 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */ 169 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize) 170 { 171 return (pgsize == 0x10000) ? 0x1000 : 0; 172 } 173 174 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, 175 unsigned long porder) 176 { 177 unsigned long i; 178 unsigned long npages; 179 unsigned long hp_v, hp_r; 180 unsigned long addr, hash; 181 unsigned long psize; 182 unsigned long hp0, hp1; 183 unsigned long idx_ret; 184 long ret; 185 struct kvm *kvm = vcpu->kvm; 186 187 psize = 1ul << porder; 188 npages = memslot->npages >> (porder - PAGE_SHIFT); 189 190 /* VRMA can't be > 1TB */ 191 if (npages > 1ul << (40 - porder)) 192 npages = 1ul << (40 - porder); 193 /* Can't use more than 1 HPTE per HPTEG */ 194 if (npages > kvm->arch.hpt_mask + 1) 195 npages = kvm->arch.hpt_mask + 1; 196 197 hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) | 198 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize); 199 hp1 = hpte1_pgsize_encoding(psize) | 200 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX; 201 202 for (i = 0; i < npages; ++i) { 203 addr = i << porder; 204 /* can't use hpt_hash since va > 64 bits */ 205 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask; 206 /* 207 * We assume that the hash table is empty and no 208 * vcpus are using it at this stage. Since we create 209 * at most one HPTE per HPTEG, we just assume entry 7 210 * is available and use it. 211 */ 212 hash = (hash << 3) + 7; 213 hp_v = hp0 | ((addr >> 16) & ~0x7fUL); 214 hp_r = hp1 | addr; 215 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r, 216 &idx_ret); 217 if (ret != H_SUCCESS) { 218 pr_err("KVM: map_vrma at %lx failed, ret=%ld\n", 219 addr, ret); 220 break; 221 } 222 } 223 } 224 225 int kvmppc_mmu_hv_init(void) 226 { 227 unsigned long host_lpid, rsvd_lpid; 228 229 if (!cpu_has_feature(CPU_FTR_HVMODE)) 230 return -EINVAL; 231 232 /* POWER7 has 10-bit LPIDs, PPC970 and e500mc have 6-bit LPIDs */ 233 if (cpu_has_feature(CPU_FTR_ARCH_206)) { 234 host_lpid = mfspr(SPRN_LPID); /* POWER7 */ 235 rsvd_lpid = LPID_RSVD; 236 } else { 237 host_lpid = 0; /* PPC970 */ 238 rsvd_lpid = MAX_LPID_970; 239 } 240 241 kvmppc_init_lpid(rsvd_lpid + 1); 242 243 kvmppc_claim_lpid(host_lpid); 244 /* rsvd_lpid is reserved for use in partition switching */ 245 kvmppc_claim_lpid(rsvd_lpid); 246 247 return 0; 248 } 249 250 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu) 251 { 252 unsigned long msr = vcpu->arch.intr_msr; 253 254 /* If transactional, change to suspend mode on IRQ delivery */ 255 if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr)) 256 msr |= MSR_TS_S; 257 else 258 msr |= vcpu->arch.shregs.msr & MSR_TS_MASK; 259 kvmppc_set_msr(vcpu, msr); 260 } 261 262 /* 263 * This is called to get a reference to a guest page if there isn't 264 * one already in the memslot->arch.slot_phys[] array. 265 */ 266 static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn, 267 struct kvm_memory_slot *memslot, 268 unsigned long psize) 269 { 270 unsigned long start; 271 long np, err; 272 struct page *page, *hpage, *pages[1]; 273 unsigned long s, pgsize; 274 unsigned long *physp; 275 unsigned int is_io, got, pgorder; 276 struct vm_area_struct *vma; 277 unsigned long pfn, i, npages; 278 279 physp = memslot->arch.slot_phys; 280 if (!physp) 281 return -EINVAL; 282 if (physp[gfn - memslot->base_gfn]) 283 return 0; 284 285 is_io = 0; 286 got = 0; 287 page = NULL; 288 pgsize = psize; 289 err = -EINVAL; 290 start = gfn_to_hva_memslot(memslot, gfn); 291 292 /* Instantiate and get the page we want access to */ 293 np = get_user_pages_fast(start, 1, 1, pages); 294 if (np != 1) { 295 /* Look up the vma for the page */ 296 down_read(¤t->mm->mmap_sem); 297 vma = find_vma(current->mm, start); 298 if (!vma || vma->vm_start > start || 299 start + psize > vma->vm_end || 300 !(vma->vm_flags & VM_PFNMAP)) 301 goto up_err; 302 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot)); 303 pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); 304 /* check alignment of pfn vs. requested page size */ 305 if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1))) 306 goto up_err; 307 up_read(¤t->mm->mmap_sem); 308 309 } else { 310 page = pages[0]; 311 got = KVMPPC_GOT_PAGE; 312 313 /* See if this is a large page */ 314 s = PAGE_SIZE; 315 if (PageHuge(page)) { 316 hpage = compound_head(page); 317 s <<= compound_order(hpage); 318 /* Get the whole large page if slot alignment is ok */ 319 if (s > psize && slot_is_aligned(memslot, s) && 320 !(memslot->userspace_addr & (s - 1))) { 321 start &= ~(s - 1); 322 pgsize = s; 323 get_page(hpage); 324 put_page(page); 325 page = hpage; 326 } 327 } 328 if (s < psize) 329 goto out; 330 pfn = page_to_pfn(page); 331 } 332 333 npages = pgsize >> PAGE_SHIFT; 334 pgorder = __ilog2(npages); 335 physp += (gfn - memslot->base_gfn) & ~(npages - 1); 336 spin_lock(&kvm->arch.slot_phys_lock); 337 for (i = 0; i < npages; ++i) { 338 if (!physp[i]) { 339 physp[i] = ((pfn + i) << PAGE_SHIFT) + 340 got + is_io + pgorder; 341 got = 0; 342 } 343 } 344 spin_unlock(&kvm->arch.slot_phys_lock); 345 err = 0; 346 347 out: 348 if (got) 349 put_page(page); 350 return err; 351 352 up_err: 353 up_read(¤t->mm->mmap_sem); 354 return err; 355 } 356 357 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 358 long pte_index, unsigned long pteh, 359 unsigned long ptel, unsigned long *pte_idx_ret) 360 { 361 unsigned long psize, gpa, gfn; 362 struct kvm_memory_slot *memslot; 363 long ret; 364 365 if (kvm->arch.using_mmu_notifiers) 366 goto do_insert; 367 368 psize = hpte_page_size(pteh, ptel); 369 if (!psize) 370 return H_PARAMETER; 371 372 pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID); 373 374 /* Find the memslot (if any) for this address */ 375 gpa = (ptel & HPTE_R_RPN) & ~(psize - 1); 376 gfn = gpa >> PAGE_SHIFT; 377 memslot = gfn_to_memslot(kvm, gfn); 378 if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) { 379 if (!slot_is_aligned(memslot, psize)) 380 return H_PARAMETER; 381 if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0) 382 return H_PARAMETER; 383 } 384 385 do_insert: 386 /* Protect linux PTE lookup from page table destruction */ 387 rcu_read_lock_sched(); /* this disables preemption too */ 388 ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel, 389 current->mm->pgd, false, pte_idx_ret); 390 rcu_read_unlock_sched(); 391 if (ret == H_TOO_HARD) { 392 /* this can't happen */ 393 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n"); 394 ret = H_RESOURCE; /* or something */ 395 } 396 return ret; 397 398 } 399 400 /* 401 * We come here on a H_ENTER call from the guest when we are not 402 * using mmu notifiers and we don't have the requested page pinned 403 * already. 404 */ 405 long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, 406 long pte_index, unsigned long pteh, 407 unsigned long ptel) 408 { 409 return kvmppc_virtmode_do_h_enter(vcpu->kvm, flags, pte_index, 410 pteh, ptel, &vcpu->arch.gpr[4]); 411 } 412 413 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu, 414 gva_t eaddr) 415 { 416 u64 mask; 417 int i; 418 419 for (i = 0; i < vcpu->arch.slb_nr; i++) { 420 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V)) 421 continue; 422 423 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T) 424 mask = ESID_MASK_1T; 425 else 426 mask = ESID_MASK; 427 428 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0) 429 return &vcpu->arch.slb[i]; 430 } 431 return NULL; 432 } 433 434 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r, 435 unsigned long ea) 436 { 437 unsigned long ra_mask; 438 439 ra_mask = hpte_page_size(v, r) - 1; 440 return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask); 441 } 442 443 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, 444 struct kvmppc_pte *gpte, bool data, bool iswrite) 445 { 446 struct kvm *kvm = vcpu->kvm; 447 struct kvmppc_slb *slbe; 448 unsigned long slb_v; 449 unsigned long pp, key; 450 unsigned long v, gr; 451 unsigned long *hptep; 452 int index; 453 int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR); 454 455 /* Get SLB entry */ 456 if (virtmode) { 457 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr); 458 if (!slbe) 459 return -EINVAL; 460 slb_v = slbe->origv; 461 } else { 462 /* real mode access */ 463 slb_v = vcpu->kvm->arch.vrma_slb_v; 464 } 465 466 preempt_disable(); 467 /* Find the HPTE in the hash table */ 468 index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, 469 HPTE_V_VALID | HPTE_V_ABSENT); 470 if (index < 0) { 471 preempt_enable(); 472 return -ENOENT; 473 } 474 hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); 475 v = hptep[0] & ~HPTE_V_HVLOCK; 476 gr = kvm->arch.revmap[index].guest_rpte; 477 478 /* Unlock the HPTE */ 479 asm volatile("lwsync" : : : "memory"); 480 hptep[0] = v; 481 preempt_enable(); 482 483 gpte->eaddr = eaddr; 484 gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff); 485 486 /* Get PP bits and key for permission check */ 487 pp = gr & (HPTE_R_PP0 | HPTE_R_PP); 488 key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS; 489 key &= slb_v; 490 491 /* Calculate permissions */ 492 gpte->may_read = hpte_read_permission(pp, key); 493 gpte->may_write = hpte_write_permission(pp, key); 494 gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G)); 495 496 /* Storage key permission check for POWER7 */ 497 if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) { 498 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr); 499 if (amrfield & 1) 500 gpte->may_read = 0; 501 if (amrfield & 2) 502 gpte->may_write = 0; 503 } 504 505 /* Get the guest physical address */ 506 gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr); 507 return 0; 508 } 509 510 /* 511 * Quick test for whether an instruction is a load or a store. 512 * If the instruction is a load or a store, then this will indicate 513 * which it is, at least on server processors. (Embedded processors 514 * have some external PID instructions that don't follow the rule 515 * embodied here.) If the instruction isn't a load or store, then 516 * this doesn't return anything useful. 517 */ 518 static int instruction_is_store(unsigned int instr) 519 { 520 unsigned int mask; 521 522 mask = 0x10000000; 523 if ((instr & 0xfc000000) == 0x7c000000) 524 mask = 0x100; /* major opcode 31 */ 525 return (instr & mask) != 0; 526 } 527 528 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, 529 unsigned long gpa, gva_t ea, int is_store) 530 { 531 int ret; 532 u32 last_inst; 533 unsigned long srr0 = kvmppc_get_pc(vcpu); 534 535 /* We try to load the last instruction. We don't let 536 * emulate_instruction do it as it doesn't check what 537 * kvmppc_ld returns. 538 * If we fail, we just return to the guest and try executing it again. 539 */ 540 if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) { 541 ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false); 542 if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED) 543 return RESUME_GUEST; 544 vcpu->arch.last_inst = last_inst; 545 } 546 547 /* 548 * WARNING: We do not know for sure whether the instruction we just 549 * read from memory is the same that caused the fault in the first 550 * place. If the instruction we read is neither an load or a store, 551 * then it can't access memory, so we don't need to worry about 552 * enforcing access permissions. So, assuming it is a load or 553 * store, we just check that its direction (load or store) is 554 * consistent with the original fault, since that's what we 555 * checked the access permissions against. If there is a mismatch 556 * we just return and retry the instruction. 557 */ 558 559 if (instruction_is_store(kvmppc_get_last_inst(vcpu)) != !!is_store) 560 return RESUME_GUEST; 561 562 /* 563 * Emulated accesses are emulated by looking at the hash for 564 * translation once, then performing the access later. The 565 * translation could be invalidated in the meantime in which 566 * point performing the subsequent memory access on the old 567 * physical address could possibly be a security hole for the 568 * guest (but not the host). 569 * 570 * This is less of an issue for MMIO stores since they aren't 571 * globally visible. It could be an issue for MMIO loads to 572 * a certain extent but we'll ignore it for now. 573 */ 574 575 vcpu->arch.paddr_accessed = gpa; 576 vcpu->arch.vaddr_accessed = ea; 577 return kvmppc_emulate_mmio(run, vcpu); 578 } 579 580 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 581 unsigned long ea, unsigned long dsisr) 582 { 583 struct kvm *kvm = vcpu->kvm; 584 unsigned long *hptep, hpte[3], r; 585 unsigned long mmu_seq, psize, pte_size; 586 unsigned long gpa_base, gfn_base; 587 unsigned long gpa, gfn, hva, pfn; 588 struct kvm_memory_slot *memslot; 589 unsigned long *rmap; 590 struct revmap_entry *rev; 591 struct page *page, *pages[1]; 592 long index, ret, npages; 593 unsigned long is_io; 594 unsigned int writing, write_ok; 595 struct vm_area_struct *vma; 596 unsigned long rcbits; 597 598 /* 599 * Real-mode code has already searched the HPT and found the 600 * entry we're interested in. Lock the entry and check that 601 * it hasn't changed. If it has, just return and re-execute the 602 * instruction. 603 */ 604 if (ea != vcpu->arch.pgfault_addr) 605 return RESUME_GUEST; 606 index = vcpu->arch.pgfault_index; 607 hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); 608 rev = &kvm->arch.revmap[index]; 609 preempt_disable(); 610 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 611 cpu_relax(); 612 hpte[0] = hptep[0] & ~HPTE_V_HVLOCK; 613 hpte[1] = hptep[1]; 614 hpte[2] = r = rev->guest_rpte; 615 asm volatile("lwsync" : : : "memory"); 616 hptep[0] = hpte[0]; 617 preempt_enable(); 618 619 if (hpte[0] != vcpu->arch.pgfault_hpte[0] || 620 hpte[1] != vcpu->arch.pgfault_hpte[1]) 621 return RESUME_GUEST; 622 623 /* Translate the logical address and get the page */ 624 psize = hpte_page_size(hpte[0], r); 625 gpa_base = r & HPTE_R_RPN & ~(psize - 1); 626 gfn_base = gpa_base >> PAGE_SHIFT; 627 gpa = gpa_base | (ea & (psize - 1)); 628 gfn = gpa >> PAGE_SHIFT; 629 memslot = gfn_to_memslot(kvm, gfn); 630 631 /* No memslot means it's an emulated MMIO region */ 632 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 633 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, 634 dsisr & DSISR_ISSTORE); 635 636 if (!kvm->arch.using_mmu_notifiers) 637 return -EFAULT; /* should never get here */ 638 639 /* 640 * This should never happen, because of the slot_is_aligned() 641 * check in kvmppc_do_h_enter(). 642 */ 643 if (gfn_base < memslot->base_gfn) 644 return -EFAULT; 645 646 /* used to check for invalidations in progress */ 647 mmu_seq = kvm->mmu_notifier_seq; 648 smp_rmb(); 649 650 is_io = 0; 651 pfn = 0; 652 page = NULL; 653 pte_size = PAGE_SIZE; 654 writing = (dsisr & DSISR_ISSTORE) != 0; 655 /* If writing != 0, then the HPTE must allow writing, if we get here */ 656 write_ok = writing; 657 hva = gfn_to_hva_memslot(memslot, gfn); 658 npages = get_user_pages_fast(hva, 1, writing, pages); 659 if (npages < 1) { 660 /* Check if it's an I/O mapping */ 661 down_read(¤t->mm->mmap_sem); 662 vma = find_vma(current->mm, hva); 663 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end && 664 (vma->vm_flags & VM_PFNMAP)) { 665 pfn = vma->vm_pgoff + 666 ((hva - vma->vm_start) >> PAGE_SHIFT); 667 pte_size = psize; 668 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot)); 669 write_ok = vma->vm_flags & VM_WRITE; 670 } 671 up_read(¤t->mm->mmap_sem); 672 if (!pfn) 673 return -EFAULT; 674 } else { 675 page = pages[0]; 676 pfn = page_to_pfn(page); 677 if (PageHuge(page)) { 678 page = compound_head(page); 679 pte_size <<= compound_order(page); 680 } 681 /* if the guest wants write access, see if that is OK */ 682 if (!writing && hpte_is_writable(r)) { 683 unsigned int hugepage_shift; 684 pte_t *ptep, pte; 685 686 /* 687 * We need to protect against page table destruction 688 * while looking up and updating the pte. 689 */ 690 rcu_read_lock_sched(); 691 ptep = find_linux_pte_or_hugepte(current->mm->pgd, 692 hva, &hugepage_shift); 693 if (ptep) { 694 pte = kvmppc_read_update_linux_pte(ptep, 1, 695 hugepage_shift); 696 if (pte_write(pte)) 697 write_ok = 1; 698 } 699 rcu_read_unlock_sched(); 700 } 701 } 702 703 ret = -EFAULT; 704 if (psize > pte_size) 705 goto out_put; 706 707 /* Check WIMG vs. the actual page we're accessing */ 708 if (!hpte_cache_flags_ok(r, is_io)) { 709 if (is_io) 710 return -EFAULT; 711 /* 712 * Allow guest to map emulated device memory as 713 * uncacheable, but actually make it cacheable. 714 */ 715 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M; 716 } 717 718 /* 719 * Set the HPTE to point to pfn. 720 * Since the pfn is at PAGE_SIZE granularity, make sure we 721 * don't mask out lower-order bits if psize < PAGE_SIZE. 722 */ 723 if (psize < PAGE_SIZE) 724 psize = PAGE_SIZE; 725 r = (r & ~(HPTE_R_PP0 - psize)) | ((pfn << PAGE_SHIFT) & ~(psize - 1)); 726 if (hpte_is_writable(r) && !write_ok) 727 r = hpte_make_readonly(r); 728 ret = RESUME_GUEST; 729 preempt_disable(); 730 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 731 cpu_relax(); 732 if ((hptep[0] & ~HPTE_V_HVLOCK) != hpte[0] || hptep[1] != hpte[1] || 733 rev->guest_rpte != hpte[2]) 734 /* HPTE has been changed under us; let the guest retry */ 735 goto out_unlock; 736 hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 737 738 /* Always put the HPTE in the rmap chain for the page base address */ 739 rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn]; 740 lock_rmap(rmap); 741 742 /* Check if we might have been invalidated; let the guest retry if so */ 743 ret = RESUME_GUEST; 744 if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) { 745 unlock_rmap(rmap); 746 goto out_unlock; 747 } 748 749 /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */ 750 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT; 751 r &= rcbits | ~(HPTE_R_R | HPTE_R_C); 752 753 if (hptep[0] & HPTE_V_VALID) { 754 /* HPTE was previously valid, so we need to invalidate it */ 755 unlock_rmap(rmap); 756 hptep[0] |= HPTE_V_ABSENT; 757 kvmppc_invalidate_hpte(kvm, hptep, index); 758 /* don't lose previous R and C bits */ 759 r |= hptep[1] & (HPTE_R_R | HPTE_R_C); 760 } else { 761 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0); 762 } 763 764 hptep[1] = r; 765 eieio(); 766 hptep[0] = hpte[0]; 767 asm volatile("ptesync" : : : "memory"); 768 preempt_enable(); 769 if (page && hpte_is_writable(r)) 770 SetPageDirty(page); 771 772 out_put: 773 if (page) { 774 /* 775 * We drop pages[0] here, not page because page might 776 * have been set to the head page of a compound, but 777 * we have to drop the reference on the correct tail 778 * page to match the get inside gup() 779 */ 780 put_page(pages[0]); 781 } 782 return ret; 783 784 out_unlock: 785 hptep[0] &= ~HPTE_V_HVLOCK; 786 preempt_enable(); 787 goto out_put; 788 } 789 790 static void kvmppc_rmap_reset(struct kvm *kvm) 791 { 792 struct kvm_memslots *slots; 793 struct kvm_memory_slot *memslot; 794 int srcu_idx; 795 796 srcu_idx = srcu_read_lock(&kvm->srcu); 797 slots = kvm->memslots; 798 kvm_for_each_memslot(memslot, slots) { 799 /* 800 * This assumes it is acceptable to lose reference and 801 * change bits across a reset. 802 */ 803 memset(memslot->arch.rmap, 0, 804 memslot->npages * sizeof(*memslot->arch.rmap)); 805 } 806 srcu_read_unlock(&kvm->srcu, srcu_idx); 807 } 808 809 static int kvm_handle_hva_range(struct kvm *kvm, 810 unsigned long start, 811 unsigned long end, 812 int (*handler)(struct kvm *kvm, 813 unsigned long *rmapp, 814 unsigned long gfn)) 815 { 816 int ret; 817 int retval = 0; 818 struct kvm_memslots *slots; 819 struct kvm_memory_slot *memslot; 820 821 slots = kvm_memslots(kvm); 822 kvm_for_each_memslot(memslot, slots) { 823 unsigned long hva_start, hva_end; 824 gfn_t gfn, gfn_end; 825 826 hva_start = max(start, memslot->userspace_addr); 827 hva_end = min(end, memslot->userspace_addr + 828 (memslot->npages << PAGE_SHIFT)); 829 if (hva_start >= hva_end) 830 continue; 831 /* 832 * {gfn(page) | page intersects with [hva_start, hva_end)} = 833 * {gfn, gfn+1, ..., gfn_end-1}. 834 */ 835 gfn = hva_to_gfn_memslot(hva_start, memslot); 836 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); 837 838 for (; gfn < gfn_end; ++gfn) { 839 gfn_t gfn_offset = gfn - memslot->base_gfn; 840 841 ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn); 842 retval |= ret; 843 } 844 } 845 846 return retval; 847 } 848 849 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, 850 int (*handler)(struct kvm *kvm, unsigned long *rmapp, 851 unsigned long gfn)) 852 { 853 return kvm_handle_hva_range(kvm, hva, hva + 1, handler); 854 } 855 856 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, 857 unsigned long gfn) 858 { 859 struct revmap_entry *rev = kvm->arch.revmap; 860 unsigned long h, i, j; 861 unsigned long *hptep; 862 unsigned long ptel, psize, rcbits; 863 864 for (;;) { 865 lock_rmap(rmapp); 866 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 867 unlock_rmap(rmapp); 868 break; 869 } 870 871 /* 872 * To avoid an ABBA deadlock with the HPTE lock bit, 873 * we can't spin on the HPTE lock while holding the 874 * rmap chain lock. 875 */ 876 i = *rmapp & KVMPPC_RMAP_INDEX; 877 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 878 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 879 /* unlock rmap before spinning on the HPTE lock */ 880 unlock_rmap(rmapp); 881 while (hptep[0] & HPTE_V_HVLOCK) 882 cpu_relax(); 883 continue; 884 } 885 j = rev[i].forw; 886 if (j == i) { 887 /* chain is now empty */ 888 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX); 889 } else { 890 /* remove i from chain */ 891 h = rev[i].back; 892 rev[h].forw = j; 893 rev[j].back = h; 894 rev[i].forw = rev[i].back = i; 895 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j; 896 } 897 898 /* Now check and modify the HPTE */ 899 ptel = rev[i].guest_rpte; 900 psize = hpte_page_size(hptep[0], ptel); 901 if ((hptep[0] & HPTE_V_VALID) && 902 hpte_rpn(ptel, psize) == gfn) { 903 if (kvm->arch.using_mmu_notifiers) 904 hptep[0] |= HPTE_V_ABSENT; 905 kvmppc_invalidate_hpte(kvm, hptep, i); 906 /* Harvest R and C */ 907 rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C); 908 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT; 909 if (rcbits & ~rev[i].guest_rpte) { 910 rev[i].guest_rpte = ptel | rcbits; 911 note_hpte_modification(kvm, &rev[i]); 912 } 913 } 914 unlock_rmap(rmapp); 915 hptep[0] &= ~HPTE_V_HVLOCK; 916 } 917 return 0; 918 } 919 920 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva) 921 { 922 if (kvm->arch.using_mmu_notifiers) 923 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 924 return 0; 925 } 926 927 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end) 928 { 929 if (kvm->arch.using_mmu_notifiers) 930 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp); 931 return 0; 932 } 933 934 void kvmppc_core_flush_memslot_hv(struct kvm *kvm, 935 struct kvm_memory_slot *memslot) 936 { 937 unsigned long *rmapp; 938 unsigned long gfn; 939 unsigned long n; 940 941 rmapp = memslot->arch.rmap; 942 gfn = memslot->base_gfn; 943 for (n = memslot->npages; n; --n) { 944 /* 945 * Testing the present bit without locking is OK because 946 * the memslot has been marked invalid already, and hence 947 * no new HPTEs referencing this page can be created, 948 * thus the present bit can't go from 0 to 1. 949 */ 950 if (*rmapp & KVMPPC_RMAP_PRESENT) 951 kvm_unmap_rmapp(kvm, rmapp, gfn); 952 ++rmapp; 953 ++gfn; 954 } 955 } 956 957 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 958 unsigned long gfn) 959 { 960 struct revmap_entry *rev = kvm->arch.revmap; 961 unsigned long head, i, j; 962 unsigned long *hptep; 963 int ret = 0; 964 965 retry: 966 lock_rmap(rmapp); 967 if (*rmapp & KVMPPC_RMAP_REFERENCED) { 968 *rmapp &= ~KVMPPC_RMAP_REFERENCED; 969 ret = 1; 970 } 971 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 972 unlock_rmap(rmapp); 973 return ret; 974 } 975 976 i = head = *rmapp & KVMPPC_RMAP_INDEX; 977 do { 978 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 979 j = rev[i].forw; 980 981 /* If this HPTE isn't referenced, ignore it */ 982 if (!(hptep[1] & HPTE_R_R)) 983 continue; 984 985 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 986 /* unlock rmap before spinning on the HPTE lock */ 987 unlock_rmap(rmapp); 988 while (hptep[0] & HPTE_V_HVLOCK) 989 cpu_relax(); 990 goto retry; 991 } 992 993 /* Now check and modify the HPTE */ 994 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) { 995 kvmppc_clear_ref_hpte(kvm, hptep, i); 996 if (!(rev[i].guest_rpte & HPTE_R_R)) { 997 rev[i].guest_rpte |= HPTE_R_R; 998 note_hpte_modification(kvm, &rev[i]); 999 } 1000 ret = 1; 1001 } 1002 hptep[0] &= ~HPTE_V_HVLOCK; 1003 } while ((i = j) != head); 1004 1005 unlock_rmap(rmapp); 1006 return ret; 1007 } 1008 1009 int kvm_age_hva_hv(struct kvm *kvm, unsigned long hva) 1010 { 1011 if (!kvm->arch.using_mmu_notifiers) 1012 return 0; 1013 return kvm_handle_hva(kvm, hva, kvm_age_rmapp); 1014 } 1015 1016 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 1017 unsigned long gfn) 1018 { 1019 struct revmap_entry *rev = kvm->arch.revmap; 1020 unsigned long head, i, j; 1021 unsigned long *hp; 1022 int ret = 1; 1023 1024 if (*rmapp & KVMPPC_RMAP_REFERENCED) 1025 return 1; 1026 1027 lock_rmap(rmapp); 1028 if (*rmapp & KVMPPC_RMAP_REFERENCED) 1029 goto out; 1030 1031 if (*rmapp & KVMPPC_RMAP_PRESENT) { 1032 i = head = *rmapp & KVMPPC_RMAP_INDEX; 1033 do { 1034 hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4)); 1035 j = rev[i].forw; 1036 if (hp[1] & HPTE_R_R) 1037 goto out; 1038 } while ((i = j) != head); 1039 } 1040 ret = 0; 1041 1042 out: 1043 unlock_rmap(rmapp); 1044 return ret; 1045 } 1046 1047 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva) 1048 { 1049 if (!kvm->arch.using_mmu_notifiers) 1050 return 0; 1051 return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp); 1052 } 1053 1054 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte) 1055 { 1056 if (!kvm->arch.using_mmu_notifiers) 1057 return; 1058 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 1059 } 1060 1061 static int vcpus_running(struct kvm *kvm) 1062 { 1063 return atomic_read(&kvm->arch.vcpus_running) != 0; 1064 } 1065 1066 /* 1067 * Returns the number of system pages that are dirty. 1068 * This can be more than 1 if we find a huge-page HPTE. 1069 */ 1070 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp) 1071 { 1072 struct revmap_entry *rev = kvm->arch.revmap; 1073 unsigned long head, i, j; 1074 unsigned long n; 1075 unsigned long v, r; 1076 unsigned long *hptep; 1077 int npages_dirty = 0; 1078 1079 retry: 1080 lock_rmap(rmapp); 1081 if (*rmapp & KVMPPC_RMAP_CHANGED) { 1082 *rmapp &= ~KVMPPC_RMAP_CHANGED; 1083 npages_dirty = 1; 1084 } 1085 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 1086 unlock_rmap(rmapp); 1087 return npages_dirty; 1088 } 1089 1090 i = head = *rmapp & KVMPPC_RMAP_INDEX; 1091 do { 1092 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); 1093 j = rev[i].forw; 1094 1095 /* 1096 * Checking the C (changed) bit here is racy since there 1097 * is no guarantee about when the hardware writes it back. 1098 * If the HPTE is not writable then it is stable since the 1099 * page can't be written to, and we would have done a tlbie 1100 * (which forces the hardware to complete any writeback) 1101 * when making the HPTE read-only. 1102 * If vcpus are running then this call is racy anyway 1103 * since the page could get dirtied subsequently, so we 1104 * expect there to be a further call which would pick up 1105 * any delayed C bit writeback. 1106 * Otherwise we need to do the tlbie even if C==0 in 1107 * order to pick up any delayed writeback of C. 1108 */ 1109 if (!(hptep[1] & HPTE_R_C) && 1110 (!hpte_is_writable(hptep[1]) || vcpus_running(kvm))) 1111 continue; 1112 1113 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 1114 /* unlock rmap before spinning on the HPTE lock */ 1115 unlock_rmap(rmapp); 1116 while (hptep[0] & HPTE_V_HVLOCK) 1117 cpu_relax(); 1118 goto retry; 1119 } 1120 1121 /* Now check and modify the HPTE */ 1122 if (!(hptep[0] & HPTE_V_VALID)) 1123 continue; 1124 1125 /* need to make it temporarily absent so C is stable */ 1126 hptep[0] |= HPTE_V_ABSENT; 1127 kvmppc_invalidate_hpte(kvm, hptep, i); 1128 v = hptep[0]; 1129 r = hptep[1]; 1130 if (r & HPTE_R_C) { 1131 hptep[1] = r & ~HPTE_R_C; 1132 if (!(rev[i].guest_rpte & HPTE_R_C)) { 1133 rev[i].guest_rpte |= HPTE_R_C; 1134 note_hpte_modification(kvm, &rev[i]); 1135 } 1136 n = hpte_page_size(v, r); 1137 n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT; 1138 if (n > npages_dirty) 1139 npages_dirty = n; 1140 eieio(); 1141 } 1142 v &= ~(HPTE_V_ABSENT | HPTE_V_HVLOCK); 1143 v |= HPTE_V_VALID; 1144 hptep[0] = v; 1145 } while ((i = j) != head); 1146 1147 unlock_rmap(rmapp); 1148 return npages_dirty; 1149 } 1150 1151 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, 1152 struct kvm_memory_slot *memslot, 1153 unsigned long *map) 1154 { 1155 unsigned long gfn; 1156 1157 if (!vpa->dirty || !vpa->pinned_addr) 1158 return; 1159 gfn = vpa->gpa >> PAGE_SHIFT; 1160 if (gfn < memslot->base_gfn || 1161 gfn >= memslot->base_gfn + memslot->npages) 1162 return; 1163 1164 vpa->dirty = false; 1165 if (map) 1166 __set_bit_le(gfn - memslot->base_gfn, map); 1167 } 1168 1169 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, 1170 unsigned long *map) 1171 { 1172 unsigned long i, j; 1173 unsigned long *rmapp; 1174 struct kvm_vcpu *vcpu; 1175 1176 preempt_disable(); 1177 rmapp = memslot->arch.rmap; 1178 for (i = 0; i < memslot->npages; ++i) { 1179 int npages = kvm_test_clear_dirty_npages(kvm, rmapp); 1180 /* 1181 * Note that if npages > 0 then i must be a multiple of npages, 1182 * since we always put huge-page HPTEs in the rmap chain 1183 * corresponding to their page base address. 1184 */ 1185 if (npages && map) 1186 for (j = i; npages; ++j, --npages) 1187 __set_bit_le(j, map); 1188 ++rmapp; 1189 } 1190 1191 /* Harvest dirty bits from VPA and DTL updates */ 1192 /* Note: we never modify the SLB shadow buffer areas */ 1193 kvm_for_each_vcpu(i, vcpu, kvm) { 1194 spin_lock(&vcpu->arch.vpa_update_lock); 1195 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map); 1196 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map); 1197 spin_unlock(&vcpu->arch.vpa_update_lock); 1198 } 1199 preempt_enable(); 1200 return 0; 1201 } 1202 1203 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, 1204 unsigned long *nb_ret) 1205 { 1206 struct kvm_memory_slot *memslot; 1207 unsigned long gfn = gpa >> PAGE_SHIFT; 1208 struct page *page, *pages[1]; 1209 int npages; 1210 unsigned long hva, offset; 1211 unsigned long pa; 1212 unsigned long *physp; 1213 int srcu_idx; 1214 1215 srcu_idx = srcu_read_lock(&kvm->srcu); 1216 memslot = gfn_to_memslot(kvm, gfn); 1217 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 1218 goto err; 1219 if (!kvm->arch.using_mmu_notifiers) { 1220 physp = memslot->arch.slot_phys; 1221 if (!physp) 1222 goto err; 1223 physp += gfn - memslot->base_gfn; 1224 pa = *physp; 1225 if (!pa) { 1226 if (kvmppc_get_guest_page(kvm, gfn, memslot, 1227 PAGE_SIZE) < 0) 1228 goto err; 1229 pa = *physp; 1230 } 1231 page = pfn_to_page(pa >> PAGE_SHIFT); 1232 get_page(page); 1233 } else { 1234 hva = gfn_to_hva_memslot(memslot, gfn); 1235 npages = get_user_pages_fast(hva, 1, 1, pages); 1236 if (npages < 1) 1237 goto err; 1238 page = pages[0]; 1239 } 1240 srcu_read_unlock(&kvm->srcu, srcu_idx); 1241 1242 offset = gpa & (PAGE_SIZE - 1); 1243 if (nb_ret) 1244 *nb_ret = PAGE_SIZE - offset; 1245 return page_address(page) + offset; 1246 1247 err: 1248 srcu_read_unlock(&kvm->srcu, srcu_idx); 1249 return NULL; 1250 } 1251 1252 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa, 1253 bool dirty) 1254 { 1255 struct page *page = virt_to_page(va); 1256 struct kvm_memory_slot *memslot; 1257 unsigned long gfn; 1258 unsigned long *rmap; 1259 int srcu_idx; 1260 1261 put_page(page); 1262 1263 if (!dirty || !kvm->arch.using_mmu_notifiers) 1264 return; 1265 1266 /* We need to mark this page dirty in the rmap chain */ 1267 gfn = gpa >> PAGE_SHIFT; 1268 srcu_idx = srcu_read_lock(&kvm->srcu); 1269 memslot = gfn_to_memslot(kvm, gfn); 1270 if (memslot) { 1271 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 1272 lock_rmap(rmap); 1273 *rmap |= KVMPPC_RMAP_CHANGED; 1274 unlock_rmap(rmap); 1275 } 1276 srcu_read_unlock(&kvm->srcu, srcu_idx); 1277 } 1278 1279 /* 1280 * Functions for reading and writing the hash table via reads and 1281 * writes on a file descriptor. 1282 * 1283 * Reads return the guest view of the hash table, which has to be 1284 * pieced together from the real hash table and the guest_rpte 1285 * values in the revmap array. 1286 * 1287 * On writes, each HPTE written is considered in turn, and if it 1288 * is valid, it is written to the HPT as if an H_ENTER with the 1289 * exact flag set was done. When the invalid count is non-zero 1290 * in the header written to the stream, the kernel will make 1291 * sure that that many HPTEs are invalid, and invalidate them 1292 * if not. 1293 */ 1294 1295 struct kvm_htab_ctx { 1296 unsigned long index; 1297 unsigned long flags; 1298 struct kvm *kvm; 1299 int first_pass; 1300 }; 1301 1302 #define HPTE_SIZE (2 * sizeof(unsigned long)) 1303 1304 /* 1305 * Returns 1 if this HPT entry has been modified or has pending 1306 * R/C bit changes. 1307 */ 1308 static int hpte_dirty(struct revmap_entry *revp, unsigned long *hptp) 1309 { 1310 unsigned long rcbits_unset; 1311 1312 if (revp->guest_rpte & HPTE_GR_MODIFIED) 1313 return 1; 1314 1315 /* Also need to consider changes in reference and changed bits */ 1316 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1317 if ((hptp[0] & HPTE_V_VALID) && (hptp[1] & rcbits_unset)) 1318 return 1; 1319 1320 return 0; 1321 } 1322 1323 static long record_hpte(unsigned long flags, unsigned long *hptp, 1324 unsigned long *hpte, struct revmap_entry *revp, 1325 int want_valid, int first_pass) 1326 { 1327 unsigned long v, r; 1328 unsigned long rcbits_unset; 1329 int ok = 1; 1330 int valid, dirty; 1331 1332 /* Unmodified entries are uninteresting except on the first pass */ 1333 dirty = hpte_dirty(revp, hptp); 1334 if (!first_pass && !dirty) 1335 return 0; 1336 1337 valid = 0; 1338 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) { 1339 valid = 1; 1340 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && 1341 !(hptp[0] & HPTE_V_BOLTED)) 1342 valid = 0; 1343 } 1344 if (valid != want_valid) 1345 return 0; 1346 1347 v = r = 0; 1348 if (valid || dirty) { 1349 /* lock the HPTE so it's stable and read it */ 1350 preempt_disable(); 1351 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) 1352 cpu_relax(); 1353 v = hptp[0]; 1354 1355 /* re-evaluate valid and dirty from synchronized HPTE value */ 1356 valid = !!(v & HPTE_V_VALID); 1357 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); 1358 1359 /* Harvest R and C into guest view if necessary */ 1360 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1361 if (valid && (rcbits_unset & hptp[1])) { 1362 revp->guest_rpte |= (hptp[1] & (HPTE_R_R | HPTE_R_C)) | 1363 HPTE_GR_MODIFIED; 1364 dirty = 1; 1365 } 1366 1367 if (v & HPTE_V_ABSENT) { 1368 v &= ~HPTE_V_ABSENT; 1369 v |= HPTE_V_VALID; 1370 valid = 1; 1371 } 1372 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) 1373 valid = 0; 1374 1375 r = revp->guest_rpte; 1376 /* only clear modified if this is the right sort of entry */ 1377 if (valid == want_valid && dirty) { 1378 r &= ~HPTE_GR_MODIFIED; 1379 revp->guest_rpte = r; 1380 } 1381 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory"); 1382 hptp[0] &= ~HPTE_V_HVLOCK; 1383 preempt_enable(); 1384 if (!(valid == want_valid && (first_pass || dirty))) 1385 ok = 0; 1386 } 1387 hpte[0] = v; 1388 hpte[1] = r; 1389 return ok; 1390 } 1391 1392 static ssize_t kvm_htab_read(struct file *file, char __user *buf, 1393 size_t count, loff_t *ppos) 1394 { 1395 struct kvm_htab_ctx *ctx = file->private_data; 1396 struct kvm *kvm = ctx->kvm; 1397 struct kvm_get_htab_header hdr; 1398 unsigned long *hptp; 1399 struct revmap_entry *revp; 1400 unsigned long i, nb, nw; 1401 unsigned long __user *lbuf; 1402 struct kvm_get_htab_header __user *hptr; 1403 unsigned long flags; 1404 int first_pass; 1405 unsigned long hpte[2]; 1406 1407 if (!access_ok(VERIFY_WRITE, buf, count)) 1408 return -EFAULT; 1409 1410 first_pass = ctx->first_pass; 1411 flags = ctx->flags; 1412 1413 i = ctx->index; 1414 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1415 revp = kvm->arch.revmap + i; 1416 lbuf = (unsigned long __user *)buf; 1417 1418 nb = 0; 1419 while (nb + sizeof(hdr) + HPTE_SIZE < count) { 1420 /* Initialize header */ 1421 hptr = (struct kvm_get_htab_header __user *)buf; 1422 hdr.n_valid = 0; 1423 hdr.n_invalid = 0; 1424 nw = nb; 1425 nb += sizeof(hdr); 1426 lbuf = (unsigned long __user *)(buf + sizeof(hdr)); 1427 1428 /* Skip uninteresting entries, i.e. clean on not-first pass */ 1429 if (!first_pass) { 1430 while (i < kvm->arch.hpt_npte && 1431 !hpte_dirty(revp, hptp)) { 1432 ++i; 1433 hptp += 2; 1434 ++revp; 1435 } 1436 } 1437 hdr.index = i; 1438 1439 /* Grab a series of valid entries */ 1440 while (i < kvm->arch.hpt_npte && 1441 hdr.n_valid < 0xffff && 1442 nb + HPTE_SIZE < count && 1443 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) { 1444 /* valid entry, write it out */ 1445 ++hdr.n_valid; 1446 if (__put_user(hpte[0], lbuf) || 1447 __put_user(hpte[1], lbuf + 1)) 1448 return -EFAULT; 1449 nb += HPTE_SIZE; 1450 lbuf += 2; 1451 ++i; 1452 hptp += 2; 1453 ++revp; 1454 } 1455 /* Now skip invalid entries while we can */ 1456 while (i < kvm->arch.hpt_npte && 1457 hdr.n_invalid < 0xffff && 1458 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) { 1459 /* found an invalid entry */ 1460 ++hdr.n_invalid; 1461 ++i; 1462 hptp += 2; 1463 ++revp; 1464 } 1465 1466 if (hdr.n_valid || hdr.n_invalid) { 1467 /* write back the header */ 1468 if (__copy_to_user(hptr, &hdr, sizeof(hdr))) 1469 return -EFAULT; 1470 nw = nb; 1471 buf = (char __user *)lbuf; 1472 } else { 1473 nb = nw; 1474 } 1475 1476 /* Check if we've wrapped around the hash table */ 1477 if (i >= kvm->arch.hpt_npte) { 1478 i = 0; 1479 ctx->first_pass = 0; 1480 break; 1481 } 1482 } 1483 1484 ctx->index = i; 1485 1486 return nb; 1487 } 1488 1489 static ssize_t kvm_htab_write(struct file *file, const char __user *buf, 1490 size_t count, loff_t *ppos) 1491 { 1492 struct kvm_htab_ctx *ctx = file->private_data; 1493 struct kvm *kvm = ctx->kvm; 1494 struct kvm_get_htab_header hdr; 1495 unsigned long i, j; 1496 unsigned long v, r; 1497 unsigned long __user *lbuf; 1498 unsigned long *hptp; 1499 unsigned long tmp[2]; 1500 ssize_t nb; 1501 long int err, ret; 1502 int rma_setup; 1503 1504 if (!access_ok(VERIFY_READ, buf, count)) 1505 return -EFAULT; 1506 1507 /* lock out vcpus from running while we're doing this */ 1508 mutex_lock(&kvm->lock); 1509 rma_setup = kvm->arch.rma_setup_done; 1510 if (rma_setup) { 1511 kvm->arch.rma_setup_done = 0; /* temporarily */ 1512 /* order rma_setup_done vs. vcpus_running */ 1513 smp_mb(); 1514 if (atomic_read(&kvm->arch.vcpus_running)) { 1515 kvm->arch.rma_setup_done = 1; 1516 mutex_unlock(&kvm->lock); 1517 return -EBUSY; 1518 } 1519 } 1520 1521 err = 0; 1522 for (nb = 0; nb + sizeof(hdr) <= count; ) { 1523 err = -EFAULT; 1524 if (__copy_from_user(&hdr, buf, sizeof(hdr))) 1525 break; 1526 1527 err = 0; 1528 if (nb + hdr.n_valid * HPTE_SIZE > count) 1529 break; 1530 1531 nb += sizeof(hdr); 1532 buf += sizeof(hdr); 1533 1534 err = -EINVAL; 1535 i = hdr.index; 1536 if (i >= kvm->arch.hpt_npte || 1537 i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte) 1538 break; 1539 1540 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1541 lbuf = (unsigned long __user *)buf; 1542 for (j = 0; j < hdr.n_valid; ++j) { 1543 err = -EFAULT; 1544 if (__get_user(v, lbuf) || __get_user(r, lbuf + 1)) 1545 goto out; 1546 err = -EINVAL; 1547 if (!(v & HPTE_V_VALID)) 1548 goto out; 1549 lbuf += 2; 1550 nb += HPTE_SIZE; 1551 1552 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) 1553 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1554 err = -EIO; 1555 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r, 1556 tmp); 1557 if (ret != H_SUCCESS) { 1558 pr_err("kvm_htab_write ret %ld i=%ld v=%lx " 1559 "r=%lx\n", ret, i, v, r); 1560 goto out; 1561 } 1562 if (!rma_setup && is_vrma_hpte(v)) { 1563 unsigned long psize = hpte_base_page_size(v, r); 1564 unsigned long senc = slb_pgsize_encoding(psize); 1565 unsigned long lpcr; 1566 1567 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T | 1568 (VRMA_VSID << SLB_VSID_SHIFT_1T); 1569 lpcr = senc << (LPCR_VRMASD_SH - 4); 1570 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD); 1571 rma_setup = 1; 1572 } 1573 ++i; 1574 hptp += 2; 1575 } 1576 1577 for (j = 0; j < hdr.n_invalid; ++j) { 1578 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) 1579 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1580 ++i; 1581 hptp += 2; 1582 } 1583 err = 0; 1584 } 1585 1586 out: 1587 /* Order HPTE updates vs. rma_setup_done */ 1588 smp_wmb(); 1589 kvm->arch.rma_setup_done = rma_setup; 1590 mutex_unlock(&kvm->lock); 1591 1592 if (err) 1593 return err; 1594 return nb; 1595 } 1596 1597 static int kvm_htab_release(struct inode *inode, struct file *filp) 1598 { 1599 struct kvm_htab_ctx *ctx = filp->private_data; 1600 1601 filp->private_data = NULL; 1602 if (!(ctx->flags & KVM_GET_HTAB_WRITE)) 1603 atomic_dec(&ctx->kvm->arch.hpte_mod_interest); 1604 kvm_put_kvm(ctx->kvm); 1605 kfree(ctx); 1606 return 0; 1607 } 1608 1609 static const struct file_operations kvm_htab_fops = { 1610 .read = kvm_htab_read, 1611 .write = kvm_htab_write, 1612 .llseek = default_llseek, 1613 .release = kvm_htab_release, 1614 }; 1615 1616 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf) 1617 { 1618 int ret; 1619 struct kvm_htab_ctx *ctx; 1620 int rwflag; 1621 1622 /* reject flags we don't recognize */ 1623 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE)) 1624 return -EINVAL; 1625 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 1626 if (!ctx) 1627 return -ENOMEM; 1628 kvm_get_kvm(kvm); 1629 ctx->kvm = kvm; 1630 ctx->index = ghf->start_index; 1631 ctx->flags = ghf->flags; 1632 ctx->first_pass = 1; 1633 1634 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY; 1635 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC); 1636 if (ret < 0) { 1637 kvm_put_kvm(kvm); 1638 return ret; 1639 } 1640 1641 if (rwflag == O_RDONLY) { 1642 mutex_lock(&kvm->slots_lock); 1643 atomic_inc(&kvm->arch.hpte_mod_interest); 1644 /* make sure kvmppc_do_h_enter etc. see the increment */ 1645 synchronize_srcu_expedited(&kvm->srcu); 1646 mutex_unlock(&kvm->slots_lock); 1647 } 1648 1649 return ret; 1650 } 1651 1652 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) 1653 { 1654 struct kvmppc_mmu *mmu = &vcpu->arch.mmu; 1655 1656 if (cpu_has_feature(CPU_FTR_ARCH_206)) 1657 vcpu->arch.slb_nr = 32; /* POWER7 */ 1658 else 1659 vcpu->arch.slb_nr = 64; 1660 1661 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate; 1662 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr; 1663 1664 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; 1665 } 1666