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 "trace_hv.h" 41 42 /* Power architecture requires HPT is at least 256kB */ 43 #define PPC_MIN_HPT_ORDER 18 44 45 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 46 long pte_index, unsigned long pteh, 47 unsigned long ptel, unsigned long *pte_idx_ret); 48 static void kvmppc_rmap_reset(struct kvm *kvm); 49 50 long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp) 51 { 52 unsigned long hpt = 0; 53 struct revmap_entry *rev; 54 struct page *page = NULL; 55 long order = KVM_DEFAULT_HPT_ORDER; 56 57 if (htab_orderp) { 58 order = *htab_orderp; 59 if (order < PPC_MIN_HPT_ORDER) 60 order = PPC_MIN_HPT_ORDER; 61 } 62 63 kvm->arch.hpt_cma_alloc = 0; 64 page = kvm_alloc_hpt(1ul << (order - PAGE_SHIFT)); 65 if (page) { 66 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page)); 67 memset((void *)hpt, 0, (1ul << order)); 68 kvm->arch.hpt_cma_alloc = 1; 69 } 70 71 /* Lastly try successively smaller sizes from the page allocator */ 72 while (!hpt && order > PPC_MIN_HPT_ORDER) { 73 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT| 74 __GFP_NOWARN, order - PAGE_SHIFT); 75 if (!hpt) 76 --order; 77 } 78 79 if (!hpt) 80 return -ENOMEM; 81 82 kvm->arch.hpt_virt = hpt; 83 kvm->arch.hpt_order = order; 84 /* HPTEs are 2**4 bytes long */ 85 kvm->arch.hpt_npte = 1ul << (order - 4); 86 /* 128 (2**7) bytes in each HPTEG */ 87 kvm->arch.hpt_mask = (1ul << (order - 7)) - 1; 88 89 /* Allocate reverse map array */ 90 rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte); 91 if (!rev) { 92 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n"); 93 goto out_freehpt; 94 } 95 kvm->arch.revmap = rev; 96 kvm->arch.sdr1 = __pa(hpt) | (order - 18); 97 98 pr_info("KVM guest htab at %lx (order %ld), LPID %x\n", 99 hpt, order, kvm->arch.lpid); 100 101 if (htab_orderp) 102 *htab_orderp = order; 103 return 0; 104 105 out_freehpt: 106 if (kvm->arch.hpt_cma_alloc) 107 kvm_release_hpt(page, 1 << (order - PAGE_SHIFT)); 108 else 109 free_pages(hpt, order - PAGE_SHIFT); 110 return -ENOMEM; 111 } 112 113 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp) 114 { 115 long err = -EBUSY; 116 long order; 117 118 mutex_lock(&kvm->lock); 119 if (kvm->arch.rma_setup_done) { 120 kvm->arch.rma_setup_done = 0; 121 /* order rma_setup_done vs. vcpus_running */ 122 smp_mb(); 123 if (atomic_read(&kvm->arch.vcpus_running)) { 124 kvm->arch.rma_setup_done = 1; 125 goto out; 126 } 127 } 128 if (kvm->arch.hpt_virt) { 129 order = kvm->arch.hpt_order; 130 /* Set the entire HPT to 0, i.e. invalid HPTEs */ 131 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order); 132 /* 133 * Reset all the reverse-mapping chains for all memslots 134 */ 135 kvmppc_rmap_reset(kvm); 136 /* Ensure that each vcpu will flush its TLB on next entry. */ 137 cpumask_setall(&kvm->arch.need_tlb_flush); 138 *htab_orderp = order; 139 err = 0; 140 } else { 141 err = kvmppc_alloc_hpt(kvm, htab_orderp); 142 order = *htab_orderp; 143 } 144 out: 145 mutex_unlock(&kvm->lock); 146 return err; 147 } 148 149 void kvmppc_free_hpt(struct kvm *kvm) 150 { 151 kvmppc_free_lpid(kvm->arch.lpid); 152 vfree(kvm->arch.revmap); 153 if (kvm->arch.hpt_cma_alloc) 154 kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt), 155 1 << (kvm->arch.hpt_order - PAGE_SHIFT)); 156 else 157 free_pages(kvm->arch.hpt_virt, 158 kvm->arch.hpt_order - PAGE_SHIFT); 159 } 160 161 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */ 162 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize) 163 { 164 return (pgsize > 0x1000) ? HPTE_V_LARGE : 0; 165 } 166 167 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */ 168 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize) 169 { 170 return (pgsize == 0x10000) ? 0x1000 : 0; 171 } 172 173 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, 174 unsigned long porder) 175 { 176 unsigned long i; 177 unsigned long npages; 178 unsigned long hp_v, hp_r; 179 unsigned long addr, hash; 180 unsigned long psize; 181 unsigned long hp0, hp1; 182 unsigned long idx_ret; 183 long ret; 184 struct kvm *kvm = vcpu->kvm; 185 186 psize = 1ul << porder; 187 npages = memslot->npages >> (porder - PAGE_SHIFT); 188 189 /* VRMA can't be > 1TB */ 190 if (npages > 1ul << (40 - porder)) 191 npages = 1ul << (40 - porder); 192 /* Can't use more than 1 HPTE per HPTEG */ 193 if (npages > kvm->arch.hpt_mask + 1) 194 npages = kvm->arch.hpt_mask + 1; 195 196 hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) | 197 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize); 198 hp1 = hpte1_pgsize_encoding(psize) | 199 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX; 200 201 for (i = 0; i < npages; ++i) { 202 addr = i << porder; 203 /* can't use hpt_hash since va > 64 bits */ 204 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask; 205 /* 206 * We assume that the hash table is empty and no 207 * vcpus are using it at this stage. Since we create 208 * at most one HPTE per HPTEG, we just assume entry 7 209 * is available and use it. 210 */ 211 hash = (hash << 3) + 7; 212 hp_v = hp0 | ((addr >> 16) & ~0x7fUL); 213 hp_r = hp1 | addr; 214 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r, 215 &idx_ret); 216 if (ret != H_SUCCESS) { 217 pr_err("KVM: map_vrma at %lx failed, ret=%ld\n", 218 addr, ret); 219 break; 220 } 221 } 222 } 223 224 int kvmppc_mmu_hv_init(void) 225 { 226 unsigned long host_lpid, rsvd_lpid; 227 228 if (!cpu_has_feature(CPU_FTR_HVMODE)) 229 return -EINVAL; 230 231 /* POWER7 has 10-bit LPIDs (12-bit in POWER8) */ 232 host_lpid = mfspr(SPRN_LPID); 233 rsvd_lpid = LPID_RSVD; 234 235 kvmppc_init_lpid(rsvd_lpid + 1); 236 237 kvmppc_claim_lpid(host_lpid); 238 /* rsvd_lpid is reserved for use in partition switching */ 239 kvmppc_claim_lpid(rsvd_lpid); 240 241 return 0; 242 } 243 244 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu) 245 { 246 unsigned long msr = vcpu->arch.intr_msr; 247 248 /* If transactional, change to suspend mode on IRQ delivery */ 249 if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr)) 250 msr |= MSR_TS_S; 251 else 252 msr |= vcpu->arch.shregs.msr & MSR_TS_MASK; 253 kvmppc_set_msr(vcpu, msr); 254 } 255 256 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 257 long pte_index, unsigned long pteh, 258 unsigned long ptel, unsigned long *pte_idx_ret) 259 { 260 long ret; 261 262 /* Protect linux PTE lookup from page table destruction */ 263 rcu_read_lock_sched(); /* this disables preemption too */ 264 ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel, 265 current->mm->pgd, false, pte_idx_ret); 266 rcu_read_unlock_sched(); 267 if (ret == H_TOO_HARD) { 268 /* this can't happen */ 269 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n"); 270 ret = H_RESOURCE; /* or something */ 271 } 272 return ret; 273 274 } 275 276 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu, 277 gva_t eaddr) 278 { 279 u64 mask; 280 int i; 281 282 for (i = 0; i < vcpu->arch.slb_nr; i++) { 283 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V)) 284 continue; 285 286 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T) 287 mask = ESID_MASK_1T; 288 else 289 mask = ESID_MASK; 290 291 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0) 292 return &vcpu->arch.slb[i]; 293 } 294 return NULL; 295 } 296 297 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r, 298 unsigned long ea) 299 { 300 unsigned long ra_mask; 301 302 ra_mask = hpte_page_size(v, r) - 1; 303 return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask); 304 } 305 306 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, 307 struct kvmppc_pte *gpte, bool data, bool iswrite) 308 { 309 struct kvm *kvm = vcpu->kvm; 310 struct kvmppc_slb *slbe; 311 unsigned long slb_v; 312 unsigned long pp, key; 313 unsigned long v, gr; 314 __be64 *hptep; 315 int index; 316 int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR); 317 318 /* Get SLB entry */ 319 if (virtmode) { 320 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr); 321 if (!slbe) 322 return -EINVAL; 323 slb_v = slbe->origv; 324 } else { 325 /* real mode access */ 326 slb_v = vcpu->kvm->arch.vrma_slb_v; 327 } 328 329 preempt_disable(); 330 /* Find the HPTE in the hash table */ 331 index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, 332 HPTE_V_VALID | HPTE_V_ABSENT); 333 if (index < 0) { 334 preempt_enable(); 335 return -ENOENT; 336 } 337 hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4)); 338 v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK; 339 gr = kvm->arch.revmap[index].guest_rpte; 340 341 /* Unlock the HPTE */ 342 asm volatile("lwsync" : : : "memory"); 343 hptep[0] = cpu_to_be64(v); 344 preempt_enable(); 345 346 gpte->eaddr = eaddr; 347 gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff); 348 349 /* Get PP bits and key for permission check */ 350 pp = gr & (HPTE_R_PP0 | HPTE_R_PP); 351 key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS; 352 key &= slb_v; 353 354 /* Calculate permissions */ 355 gpte->may_read = hpte_read_permission(pp, key); 356 gpte->may_write = hpte_write_permission(pp, key); 357 gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G)); 358 359 /* Storage key permission check for POWER7 */ 360 if (data && virtmode) { 361 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr); 362 if (amrfield & 1) 363 gpte->may_read = 0; 364 if (amrfield & 2) 365 gpte->may_write = 0; 366 } 367 368 /* Get the guest physical address */ 369 gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr); 370 return 0; 371 } 372 373 /* 374 * Quick test for whether an instruction is a load or a store. 375 * If the instruction is a load or a store, then this will indicate 376 * which it is, at least on server processors. (Embedded processors 377 * have some external PID instructions that don't follow the rule 378 * embodied here.) If the instruction isn't a load or store, then 379 * this doesn't return anything useful. 380 */ 381 static int instruction_is_store(unsigned int instr) 382 { 383 unsigned int mask; 384 385 mask = 0x10000000; 386 if ((instr & 0xfc000000) == 0x7c000000) 387 mask = 0x100; /* major opcode 31 */ 388 return (instr & mask) != 0; 389 } 390 391 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, 392 unsigned long gpa, gva_t ea, int is_store) 393 { 394 u32 last_inst; 395 396 /* 397 * If we fail, we just return to the guest and try executing it again. 398 */ 399 if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != 400 EMULATE_DONE) 401 return RESUME_GUEST; 402 403 /* 404 * WARNING: We do not know for sure whether the instruction we just 405 * read from memory is the same that caused the fault in the first 406 * place. If the instruction we read is neither an load or a store, 407 * then it can't access memory, so we don't need to worry about 408 * enforcing access permissions. So, assuming it is a load or 409 * store, we just check that its direction (load or store) is 410 * consistent with the original fault, since that's what we 411 * checked the access permissions against. If there is a mismatch 412 * we just return and retry the instruction. 413 */ 414 415 if (instruction_is_store(last_inst) != !!is_store) 416 return RESUME_GUEST; 417 418 /* 419 * Emulated accesses are emulated by looking at the hash for 420 * translation once, then performing the access later. The 421 * translation could be invalidated in the meantime in which 422 * point performing the subsequent memory access on the old 423 * physical address could possibly be a security hole for the 424 * guest (but not the host). 425 * 426 * This is less of an issue for MMIO stores since they aren't 427 * globally visible. It could be an issue for MMIO loads to 428 * a certain extent but we'll ignore it for now. 429 */ 430 431 vcpu->arch.paddr_accessed = gpa; 432 vcpu->arch.vaddr_accessed = ea; 433 return kvmppc_emulate_mmio(run, vcpu); 434 } 435 436 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 437 unsigned long ea, unsigned long dsisr) 438 { 439 struct kvm *kvm = vcpu->kvm; 440 unsigned long hpte[3], r; 441 __be64 *hptep; 442 unsigned long mmu_seq, psize, pte_size; 443 unsigned long gpa_base, gfn_base; 444 unsigned long gpa, gfn, hva, pfn; 445 struct kvm_memory_slot *memslot; 446 unsigned long *rmap; 447 struct revmap_entry *rev; 448 struct page *page, *pages[1]; 449 long index, ret, npages; 450 unsigned long is_io; 451 unsigned int writing, write_ok; 452 struct vm_area_struct *vma; 453 unsigned long rcbits; 454 455 /* 456 * Real-mode code has already searched the HPT and found the 457 * entry we're interested in. Lock the entry and check that 458 * it hasn't changed. If it has, just return and re-execute the 459 * instruction. 460 */ 461 if (ea != vcpu->arch.pgfault_addr) 462 return RESUME_GUEST; 463 index = vcpu->arch.pgfault_index; 464 hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4)); 465 rev = &kvm->arch.revmap[index]; 466 preempt_disable(); 467 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 468 cpu_relax(); 469 hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK; 470 hpte[1] = be64_to_cpu(hptep[1]); 471 hpte[2] = r = rev->guest_rpte; 472 asm volatile("lwsync" : : : "memory"); 473 hptep[0] = cpu_to_be64(hpte[0]); 474 preempt_enable(); 475 476 if (hpte[0] != vcpu->arch.pgfault_hpte[0] || 477 hpte[1] != vcpu->arch.pgfault_hpte[1]) 478 return RESUME_GUEST; 479 480 /* Translate the logical address and get the page */ 481 psize = hpte_page_size(hpte[0], r); 482 gpa_base = r & HPTE_R_RPN & ~(psize - 1); 483 gfn_base = gpa_base >> PAGE_SHIFT; 484 gpa = gpa_base | (ea & (psize - 1)); 485 gfn = gpa >> PAGE_SHIFT; 486 memslot = gfn_to_memslot(kvm, gfn); 487 488 trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr); 489 490 /* No memslot means it's an emulated MMIO region */ 491 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 492 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, 493 dsisr & DSISR_ISSTORE); 494 495 /* 496 * This should never happen, because of the slot_is_aligned() 497 * check in kvmppc_do_h_enter(). 498 */ 499 if (gfn_base < memslot->base_gfn) 500 return -EFAULT; 501 502 /* used to check for invalidations in progress */ 503 mmu_seq = kvm->mmu_notifier_seq; 504 smp_rmb(); 505 506 ret = -EFAULT; 507 is_io = 0; 508 pfn = 0; 509 page = NULL; 510 pte_size = PAGE_SIZE; 511 writing = (dsisr & DSISR_ISSTORE) != 0; 512 /* If writing != 0, then the HPTE must allow writing, if we get here */ 513 write_ok = writing; 514 hva = gfn_to_hva_memslot(memslot, gfn); 515 npages = get_user_pages_fast(hva, 1, writing, pages); 516 if (npages < 1) { 517 /* Check if it's an I/O mapping */ 518 down_read(¤t->mm->mmap_sem); 519 vma = find_vma(current->mm, hva); 520 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end && 521 (vma->vm_flags & VM_PFNMAP)) { 522 pfn = vma->vm_pgoff + 523 ((hva - vma->vm_start) >> PAGE_SHIFT); 524 pte_size = psize; 525 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot)); 526 write_ok = vma->vm_flags & VM_WRITE; 527 } 528 up_read(¤t->mm->mmap_sem); 529 if (!pfn) 530 goto out_put; 531 } else { 532 page = pages[0]; 533 pfn = page_to_pfn(page); 534 if (PageHuge(page)) { 535 page = compound_head(page); 536 pte_size <<= compound_order(page); 537 } 538 /* if the guest wants write access, see if that is OK */ 539 if (!writing && hpte_is_writable(r)) { 540 unsigned int hugepage_shift; 541 pte_t *ptep, pte; 542 543 /* 544 * We need to protect against page table destruction 545 * while looking up and updating the pte. 546 */ 547 rcu_read_lock_sched(); 548 ptep = find_linux_pte_or_hugepte(current->mm->pgd, 549 hva, &hugepage_shift); 550 if (ptep) { 551 pte = kvmppc_read_update_linux_pte(ptep, 1, 552 hugepage_shift); 553 if (pte_write(pte)) 554 write_ok = 1; 555 } 556 rcu_read_unlock_sched(); 557 } 558 } 559 560 if (psize > pte_size) 561 goto out_put; 562 563 /* Check WIMG vs. the actual page we're accessing */ 564 if (!hpte_cache_flags_ok(r, is_io)) { 565 if (is_io) 566 goto out_put; 567 568 /* 569 * Allow guest to map emulated device memory as 570 * uncacheable, but actually make it cacheable. 571 */ 572 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M; 573 } 574 575 /* 576 * Set the HPTE to point to pfn. 577 * Since the pfn is at PAGE_SIZE granularity, make sure we 578 * don't mask out lower-order bits if psize < PAGE_SIZE. 579 */ 580 if (psize < PAGE_SIZE) 581 psize = PAGE_SIZE; 582 r = (r & ~(HPTE_R_PP0 - psize)) | ((pfn << PAGE_SHIFT) & ~(psize - 1)); 583 if (hpte_is_writable(r) && !write_ok) 584 r = hpte_make_readonly(r); 585 ret = RESUME_GUEST; 586 preempt_disable(); 587 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 588 cpu_relax(); 589 if ((be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK) != hpte[0] || 590 be64_to_cpu(hptep[1]) != hpte[1] || 591 rev->guest_rpte != hpte[2]) 592 /* HPTE has been changed under us; let the guest retry */ 593 goto out_unlock; 594 hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 595 596 /* Always put the HPTE in the rmap chain for the page base address */ 597 rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn]; 598 lock_rmap(rmap); 599 600 /* Check if we might have been invalidated; let the guest retry if so */ 601 ret = RESUME_GUEST; 602 if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) { 603 unlock_rmap(rmap); 604 goto out_unlock; 605 } 606 607 /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */ 608 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT; 609 r &= rcbits | ~(HPTE_R_R | HPTE_R_C); 610 611 if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) { 612 /* HPTE was previously valid, so we need to invalidate it */ 613 unlock_rmap(rmap); 614 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT); 615 kvmppc_invalidate_hpte(kvm, hptep, index); 616 /* don't lose previous R and C bits */ 617 r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C); 618 } else { 619 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0); 620 } 621 622 hptep[1] = cpu_to_be64(r); 623 eieio(); 624 hptep[0] = cpu_to_be64(hpte[0]); 625 asm volatile("ptesync" : : : "memory"); 626 preempt_enable(); 627 if (page && hpte_is_writable(r)) 628 SetPageDirty(page); 629 630 out_put: 631 trace_kvm_page_fault_exit(vcpu, hpte, ret); 632 633 if (page) { 634 /* 635 * We drop pages[0] here, not page because page might 636 * have been set to the head page of a compound, but 637 * we have to drop the reference on the correct tail 638 * page to match the get inside gup() 639 */ 640 put_page(pages[0]); 641 } 642 return ret; 643 644 out_unlock: 645 hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK); 646 preempt_enable(); 647 goto out_put; 648 } 649 650 static void kvmppc_rmap_reset(struct kvm *kvm) 651 { 652 struct kvm_memslots *slots; 653 struct kvm_memory_slot *memslot; 654 int srcu_idx; 655 656 srcu_idx = srcu_read_lock(&kvm->srcu); 657 slots = kvm->memslots; 658 kvm_for_each_memslot(memslot, slots) { 659 /* 660 * This assumes it is acceptable to lose reference and 661 * change bits across a reset. 662 */ 663 memset(memslot->arch.rmap, 0, 664 memslot->npages * sizeof(*memslot->arch.rmap)); 665 } 666 srcu_read_unlock(&kvm->srcu, srcu_idx); 667 } 668 669 static int kvm_handle_hva_range(struct kvm *kvm, 670 unsigned long start, 671 unsigned long end, 672 int (*handler)(struct kvm *kvm, 673 unsigned long *rmapp, 674 unsigned long gfn)) 675 { 676 int ret; 677 int retval = 0; 678 struct kvm_memslots *slots; 679 struct kvm_memory_slot *memslot; 680 681 slots = kvm_memslots(kvm); 682 kvm_for_each_memslot(memslot, slots) { 683 unsigned long hva_start, hva_end; 684 gfn_t gfn, gfn_end; 685 686 hva_start = max(start, memslot->userspace_addr); 687 hva_end = min(end, memslot->userspace_addr + 688 (memslot->npages << PAGE_SHIFT)); 689 if (hva_start >= hva_end) 690 continue; 691 /* 692 * {gfn(page) | page intersects with [hva_start, hva_end)} = 693 * {gfn, gfn+1, ..., gfn_end-1}. 694 */ 695 gfn = hva_to_gfn_memslot(hva_start, memslot); 696 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); 697 698 for (; gfn < gfn_end; ++gfn) { 699 gfn_t gfn_offset = gfn - memslot->base_gfn; 700 701 ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn); 702 retval |= ret; 703 } 704 } 705 706 return retval; 707 } 708 709 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, 710 int (*handler)(struct kvm *kvm, unsigned long *rmapp, 711 unsigned long gfn)) 712 { 713 return kvm_handle_hva_range(kvm, hva, hva + 1, handler); 714 } 715 716 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, 717 unsigned long gfn) 718 { 719 struct revmap_entry *rev = kvm->arch.revmap; 720 unsigned long h, i, j; 721 __be64 *hptep; 722 unsigned long ptel, psize, rcbits; 723 724 for (;;) { 725 lock_rmap(rmapp); 726 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 727 unlock_rmap(rmapp); 728 break; 729 } 730 731 /* 732 * To avoid an ABBA deadlock with the HPTE lock bit, 733 * we can't spin on the HPTE lock while holding the 734 * rmap chain lock. 735 */ 736 i = *rmapp & KVMPPC_RMAP_INDEX; 737 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4)); 738 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 739 /* unlock rmap before spinning on the HPTE lock */ 740 unlock_rmap(rmapp); 741 while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK) 742 cpu_relax(); 743 continue; 744 } 745 j = rev[i].forw; 746 if (j == i) { 747 /* chain is now empty */ 748 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX); 749 } else { 750 /* remove i from chain */ 751 h = rev[i].back; 752 rev[h].forw = j; 753 rev[j].back = h; 754 rev[i].forw = rev[i].back = i; 755 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j; 756 } 757 758 /* Now check and modify the HPTE */ 759 ptel = rev[i].guest_rpte; 760 psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel); 761 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) && 762 hpte_rpn(ptel, psize) == gfn) { 763 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT); 764 kvmppc_invalidate_hpte(kvm, hptep, i); 765 /* Harvest R and C */ 766 rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C); 767 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT; 768 if (rcbits & ~rev[i].guest_rpte) { 769 rev[i].guest_rpte = ptel | rcbits; 770 note_hpte_modification(kvm, &rev[i]); 771 } 772 } 773 unlock_rmap(rmapp); 774 hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK); 775 } 776 return 0; 777 } 778 779 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva) 780 { 781 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 782 return 0; 783 } 784 785 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end) 786 { 787 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp); 788 return 0; 789 } 790 791 void kvmppc_core_flush_memslot_hv(struct kvm *kvm, 792 struct kvm_memory_slot *memslot) 793 { 794 unsigned long *rmapp; 795 unsigned long gfn; 796 unsigned long n; 797 798 rmapp = memslot->arch.rmap; 799 gfn = memslot->base_gfn; 800 for (n = memslot->npages; n; --n) { 801 /* 802 * Testing the present bit without locking is OK because 803 * the memslot has been marked invalid already, and hence 804 * no new HPTEs referencing this page can be created, 805 * thus the present bit can't go from 0 to 1. 806 */ 807 if (*rmapp & KVMPPC_RMAP_PRESENT) 808 kvm_unmap_rmapp(kvm, rmapp, gfn); 809 ++rmapp; 810 ++gfn; 811 } 812 } 813 814 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 815 unsigned long gfn) 816 { 817 struct revmap_entry *rev = kvm->arch.revmap; 818 unsigned long head, i, j; 819 __be64 *hptep; 820 int ret = 0; 821 822 retry: 823 lock_rmap(rmapp); 824 if (*rmapp & KVMPPC_RMAP_REFERENCED) { 825 *rmapp &= ~KVMPPC_RMAP_REFERENCED; 826 ret = 1; 827 } 828 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 829 unlock_rmap(rmapp); 830 return ret; 831 } 832 833 i = head = *rmapp & KVMPPC_RMAP_INDEX; 834 do { 835 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4)); 836 j = rev[i].forw; 837 838 /* If this HPTE isn't referenced, ignore it */ 839 if (!(be64_to_cpu(hptep[1]) & HPTE_R_R)) 840 continue; 841 842 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 843 /* unlock rmap before spinning on the HPTE lock */ 844 unlock_rmap(rmapp); 845 while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK) 846 cpu_relax(); 847 goto retry; 848 } 849 850 /* Now check and modify the HPTE */ 851 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) && 852 (be64_to_cpu(hptep[1]) & HPTE_R_R)) { 853 kvmppc_clear_ref_hpte(kvm, hptep, i); 854 if (!(rev[i].guest_rpte & HPTE_R_R)) { 855 rev[i].guest_rpte |= HPTE_R_R; 856 note_hpte_modification(kvm, &rev[i]); 857 } 858 ret = 1; 859 } 860 hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK); 861 } while ((i = j) != head); 862 863 unlock_rmap(rmapp); 864 return ret; 865 } 866 867 int kvm_age_hva_hv(struct kvm *kvm, unsigned long start, unsigned long end) 868 { 869 return kvm_handle_hva_range(kvm, start, end, kvm_age_rmapp); 870 } 871 872 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 873 unsigned long gfn) 874 { 875 struct revmap_entry *rev = kvm->arch.revmap; 876 unsigned long head, i, j; 877 unsigned long *hp; 878 int ret = 1; 879 880 if (*rmapp & KVMPPC_RMAP_REFERENCED) 881 return 1; 882 883 lock_rmap(rmapp); 884 if (*rmapp & KVMPPC_RMAP_REFERENCED) 885 goto out; 886 887 if (*rmapp & KVMPPC_RMAP_PRESENT) { 888 i = head = *rmapp & KVMPPC_RMAP_INDEX; 889 do { 890 hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4)); 891 j = rev[i].forw; 892 if (be64_to_cpu(hp[1]) & HPTE_R_R) 893 goto out; 894 } while ((i = j) != head); 895 } 896 ret = 0; 897 898 out: 899 unlock_rmap(rmapp); 900 return ret; 901 } 902 903 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva) 904 { 905 return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp); 906 } 907 908 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte) 909 { 910 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 911 } 912 913 static int vcpus_running(struct kvm *kvm) 914 { 915 return atomic_read(&kvm->arch.vcpus_running) != 0; 916 } 917 918 /* 919 * Returns the number of system pages that are dirty. 920 * This can be more than 1 if we find a huge-page HPTE. 921 */ 922 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp) 923 { 924 struct revmap_entry *rev = kvm->arch.revmap; 925 unsigned long head, i, j; 926 unsigned long n; 927 unsigned long v, r; 928 __be64 *hptep; 929 int npages_dirty = 0; 930 931 retry: 932 lock_rmap(rmapp); 933 if (*rmapp & KVMPPC_RMAP_CHANGED) { 934 *rmapp &= ~KVMPPC_RMAP_CHANGED; 935 npages_dirty = 1; 936 } 937 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 938 unlock_rmap(rmapp); 939 return npages_dirty; 940 } 941 942 i = head = *rmapp & KVMPPC_RMAP_INDEX; 943 do { 944 unsigned long hptep1; 945 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4)); 946 j = rev[i].forw; 947 948 /* 949 * Checking the C (changed) bit here is racy since there 950 * is no guarantee about when the hardware writes it back. 951 * If the HPTE is not writable then it is stable since the 952 * page can't be written to, and we would have done a tlbie 953 * (which forces the hardware to complete any writeback) 954 * when making the HPTE read-only. 955 * If vcpus are running then this call is racy anyway 956 * since the page could get dirtied subsequently, so we 957 * expect there to be a further call which would pick up 958 * any delayed C bit writeback. 959 * Otherwise we need to do the tlbie even if C==0 in 960 * order to pick up any delayed writeback of C. 961 */ 962 hptep1 = be64_to_cpu(hptep[1]); 963 if (!(hptep1 & HPTE_R_C) && 964 (!hpte_is_writable(hptep1) || vcpus_running(kvm))) 965 continue; 966 967 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 968 /* unlock rmap before spinning on the HPTE lock */ 969 unlock_rmap(rmapp); 970 while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK)) 971 cpu_relax(); 972 goto retry; 973 } 974 975 /* Now check and modify the HPTE */ 976 if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) { 977 /* unlock and continue */ 978 hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK); 979 continue; 980 } 981 982 /* need to make it temporarily absent so C is stable */ 983 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT); 984 kvmppc_invalidate_hpte(kvm, hptep, i); 985 v = be64_to_cpu(hptep[0]); 986 r = be64_to_cpu(hptep[1]); 987 if (r & HPTE_R_C) { 988 hptep[1] = cpu_to_be64(r & ~HPTE_R_C); 989 if (!(rev[i].guest_rpte & HPTE_R_C)) { 990 rev[i].guest_rpte |= HPTE_R_C; 991 note_hpte_modification(kvm, &rev[i]); 992 } 993 n = hpte_page_size(v, r); 994 n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT; 995 if (n > npages_dirty) 996 npages_dirty = n; 997 eieio(); 998 } 999 v &= ~(HPTE_V_ABSENT | HPTE_V_HVLOCK); 1000 v |= HPTE_V_VALID; 1001 hptep[0] = cpu_to_be64(v); 1002 } while ((i = j) != head); 1003 1004 unlock_rmap(rmapp); 1005 return npages_dirty; 1006 } 1007 1008 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, 1009 struct kvm_memory_slot *memslot, 1010 unsigned long *map) 1011 { 1012 unsigned long gfn; 1013 1014 if (!vpa->dirty || !vpa->pinned_addr) 1015 return; 1016 gfn = vpa->gpa >> PAGE_SHIFT; 1017 if (gfn < memslot->base_gfn || 1018 gfn >= memslot->base_gfn + memslot->npages) 1019 return; 1020 1021 vpa->dirty = false; 1022 if (map) 1023 __set_bit_le(gfn - memslot->base_gfn, map); 1024 } 1025 1026 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, 1027 unsigned long *map) 1028 { 1029 unsigned long i, j; 1030 unsigned long *rmapp; 1031 struct kvm_vcpu *vcpu; 1032 1033 preempt_disable(); 1034 rmapp = memslot->arch.rmap; 1035 for (i = 0; i < memslot->npages; ++i) { 1036 int npages = kvm_test_clear_dirty_npages(kvm, rmapp); 1037 /* 1038 * Note that if npages > 0 then i must be a multiple of npages, 1039 * since we always put huge-page HPTEs in the rmap chain 1040 * corresponding to their page base address. 1041 */ 1042 if (npages && map) 1043 for (j = i; npages; ++j, --npages) 1044 __set_bit_le(j, map); 1045 ++rmapp; 1046 } 1047 1048 /* Harvest dirty bits from VPA and DTL updates */ 1049 /* Note: we never modify the SLB shadow buffer areas */ 1050 kvm_for_each_vcpu(i, vcpu, kvm) { 1051 spin_lock(&vcpu->arch.vpa_update_lock); 1052 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map); 1053 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map); 1054 spin_unlock(&vcpu->arch.vpa_update_lock); 1055 } 1056 preempt_enable(); 1057 return 0; 1058 } 1059 1060 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, 1061 unsigned long *nb_ret) 1062 { 1063 struct kvm_memory_slot *memslot; 1064 unsigned long gfn = gpa >> PAGE_SHIFT; 1065 struct page *page, *pages[1]; 1066 int npages; 1067 unsigned long hva, offset; 1068 int srcu_idx; 1069 1070 srcu_idx = srcu_read_lock(&kvm->srcu); 1071 memslot = gfn_to_memslot(kvm, gfn); 1072 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 1073 goto err; 1074 hva = gfn_to_hva_memslot(memslot, gfn); 1075 npages = get_user_pages_fast(hva, 1, 1, pages); 1076 if (npages < 1) 1077 goto err; 1078 page = pages[0]; 1079 srcu_read_unlock(&kvm->srcu, srcu_idx); 1080 1081 offset = gpa & (PAGE_SIZE - 1); 1082 if (nb_ret) 1083 *nb_ret = PAGE_SIZE - offset; 1084 return page_address(page) + offset; 1085 1086 err: 1087 srcu_read_unlock(&kvm->srcu, srcu_idx); 1088 return NULL; 1089 } 1090 1091 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa, 1092 bool dirty) 1093 { 1094 struct page *page = virt_to_page(va); 1095 struct kvm_memory_slot *memslot; 1096 unsigned long gfn; 1097 unsigned long *rmap; 1098 int srcu_idx; 1099 1100 put_page(page); 1101 1102 if (!dirty) 1103 return; 1104 1105 /* We need to mark this page dirty in the rmap chain */ 1106 gfn = gpa >> PAGE_SHIFT; 1107 srcu_idx = srcu_read_lock(&kvm->srcu); 1108 memslot = gfn_to_memslot(kvm, gfn); 1109 if (memslot) { 1110 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 1111 lock_rmap(rmap); 1112 *rmap |= KVMPPC_RMAP_CHANGED; 1113 unlock_rmap(rmap); 1114 } 1115 srcu_read_unlock(&kvm->srcu, srcu_idx); 1116 } 1117 1118 /* 1119 * Functions for reading and writing the hash table via reads and 1120 * writes on a file descriptor. 1121 * 1122 * Reads return the guest view of the hash table, which has to be 1123 * pieced together from the real hash table and the guest_rpte 1124 * values in the revmap array. 1125 * 1126 * On writes, each HPTE written is considered in turn, and if it 1127 * is valid, it is written to the HPT as if an H_ENTER with the 1128 * exact flag set was done. When the invalid count is non-zero 1129 * in the header written to the stream, the kernel will make 1130 * sure that that many HPTEs are invalid, and invalidate them 1131 * if not. 1132 */ 1133 1134 struct kvm_htab_ctx { 1135 unsigned long index; 1136 unsigned long flags; 1137 struct kvm *kvm; 1138 int first_pass; 1139 }; 1140 1141 #define HPTE_SIZE (2 * sizeof(unsigned long)) 1142 1143 /* 1144 * Returns 1 if this HPT entry has been modified or has pending 1145 * R/C bit changes. 1146 */ 1147 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp) 1148 { 1149 unsigned long rcbits_unset; 1150 1151 if (revp->guest_rpte & HPTE_GR_MODIFIED) 1152 return 1; 1153 1154 /* Also need to consider changes in reference and changed bits */ 1155 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1156 if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) && 1157 (be64_to_cpu(hptp[1]) & rcbits_unset)) 1158 return 1; 1159 1160 return 0; 1161 } 1162 1163 static long record_hpte(unsigned long flags, __be64 *hptp, 1164 unsigned long *hpte, struct revmap_entry *revp, 1165 int want_valid, int first_pass) 1166 { 1167 unsigned long v, r; 1168 unsigned long rcbits_unset; 1169 int ok = 1; 1170 int valid, dirty; 1171 1172 /* Unmodified entries are uninteresting except on the first pass */ 1173 dirty = hpte_dirty(revp, hptp); 1174 if (!first_pass && !dirty) 1175 return 0; 1176 1177 valid = 0; 1178 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) { 1179 valid = 1; 1180 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && 1181 !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED)) 1182 valid = 0; 1183 } 1184 if (valid != want_valid) 1185 return 0; 1186 1187 v = r = 0; 1188 if (valid || dirty) { 1189 /* lock the HPTE so it's stable and read it */ 1190 preempt_disable(); 1191 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) 1192 cpu_relax(); 1193 v = be64_to_cpu(hptp[0]); 1194 1195 /* re-evaluate valid and dirty from synchronized HPTE value */ 1196 valid = !!(v & HPTE_V_VALID); 1197 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); 1198 1199 /* Harvest R and C into guest view if necessary */ 1200 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1201 if (valid && (rcbits_unset & be64_to_cpu(hptp[1]))) { 1202 revp->guest_rpte |= (be64_to_cpu(hptp[1]) & 1203 (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED; 1204 dirty = 1; 1205 } 1206 1207 if (v & HPTE_V_ABSENT) { 1208 v &= ~HPTE_V_ABSENT; 1209 v |= HPTE_V_VALID; 1210 valid = 1; 1211 } 1212 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) 1213 valid = 0; 1214 1215 r = revp->guest_rpte; 1216 /* only clear modified if this is the right sort of entry */ 1217 if (valid == want_valid && dirty) { 1218 r &= ~HPTE_GR_MODIFIED; 1219 revp->guest_rpte = r; 1220 } 1221 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory"); 1222 hptp[0] &= ~cpu_to_be64(HPTE_V_HVLOCK); 1223 preempt_enable(); 1224 if (!(valid == want_valid && (first_pass || dirty))) 1225 ok = 0; 1226 } 1227 hpte[0] = cpu_to_be64(v); 1228 hpte[1] = cpu_to_be64(r); 1229 return ok; 1230 } 1231 1232 static ssize_t kvm_htab_read(struct file *file, char __user *buf, 1233 size_t count, loff_t *ppos) 1234 { 1235 struct kvm_htab_ctx *ctx = file->private_data; 1236 struct kvm *kvm = ctx->kvm; 1237 struct kvm_get_htab_header hdr; 1238 __be64 *hptp; 1239 struct revmap_entry *revp; 1240 unsigned long i, nb, nw; 1241 unsigned long __user *lbuf; 1242 struct kvm_get_htab_header __user *hptr; 1243 unsigned long flags; 1244 int first_pass; 1245 unsigned long hpte[2]; 1246 1247 if (!access_ok(VERIFY_WRITE, buf, count)) 1248 return -EFAULT; 1249 1250 first_pass = ctx->first_pass; 1251 flags = ctx->flags; 1252 1253 i = ctx->index; 1254 hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1255 revp = kvm->arch.revmap + i; 1256 lbuf = (unsigned long __user *)buf; 1257 1258 nb = 0; 1259 while (nb + sizeof(hdr) + HPTE_SIZE < count) { 1260 /* Initialize header */ 1261 hptr = (struct kvm_get_htab_header __user *)buf; 1262 hdr.n_valid = 0; 1263 hdr.n_invalid = 0; 1264 nw = nb; 1265 nb += sizeof(hdr); 1266 lbuf = (unsigned long __user *)(buf + sizeof(hdr)); 1267 1268 /* Skip uninteresting entries, i.e. clean on not-first pass */ 1269 if (!first_pass) { 1270 while (i < kvm->arch.hpt_npte && 1271 !hpte_dirty(revp, hptp)) { 1272 ++i; 1273 hptp += 2; 1274 ++revp; 1275 } 1276 } 1277 hdr.index = i; 1278 1279 /* Grab a series of valid entries */ 1280 while (i < kvm->arch.hpt_npte && 1281 hdr.n_valid < 0xffff && 1282 nb + HPTE_SIZE < count && 1283 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) { 1284 /* valid entry, write it out */ 1285 ++hdr.n_valid; 1286 if (__put_user(hpte[0], lbuf) || 1287 __put_user(hpte[1], lbuf + 1)) 1288 return -EFAULT; 1289 nb += HPTE_SIZE; 1290 lbuf += 2; 1291 ++i; 1292 hptp += 2; 1293 ++revp; 1294 } 1295 /* Now skip invalid entries while we can */ 1296 while (i < kvm->arch.hpt_npte && 1297 hdr.n_invalid < 0xffff && 1298 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) { 1299 /* found an invalid entry */ 1300 ++hdr.n_invalid; 1301 ++i; 1302 hptp += 2; 1303 ++revp; 1304 } 1305 1306 if (hdr.n_valid || hdr.n_invalid) { 1307 /* write back the header */ 1308 if (__copy_to_user(hptr, &hdr, sizeof(hdr))) 1309 return -EFAULT; 1310 nw = nb; 1311 buf = (char __user *)lbuf; 1312 } else { 1313 nb = nw; 1314 } 1315 1316 /* Check if we've wrapped around the hash table */ 1317 if (i >= kvm->arch.hpt_npte) { 1318 i = 0; 1319 ctx->first_pass = 0; 1320 break; 1321 } 1322 } 1323 1324 ctx->index = i; 1325 1326 return nb; 1327 } 1328 1329 static ssize_t kvm_htab_write(struct file *file, const char __user *buf, 1330 size_t count, loff_t *ppos) 1331 { 1332 struct kvm_htab_ctx *ctx = file->private_data; 1333 struct kvm *kvm = ctx->kvm; 1334 struct kvm_get_htab_header hdr; 1335 unsigned long i, j; 1336 unsigned long v, r; 1337 unsigned long __user *lbuf; 1338 __be64 *hptp; 1339 unsigned long tmp[2]; 1340 ssize_t nb; 1341 long int err, ret; 1342 int rma_setup; 1343 1344 if (!access_ok(VERIFY_READ, buf, count)) 1345 return -EFAULT; 1346 1347 /* lock out vcpus from running while we're doing this */ 1348 mutex_lock(&kvm->lock); 1349 rma_setup = kvm->arch.rma_setup_done; 1350 if (rma_setup) { 1351 kvm->arch.rma_setup_done = 0; /* temporarily */ 1352 /* order rma_setup_done vs. vcpus_running */ 1353 smp_mb(); 1354 if (atomic_read(&kvm->arch.vcpus_running)) { 1355 kvm->arch.rma_setup_done = 1; 1356 mutex_unlock(&kvm->lock); 1357 return -EBUSY; 1358 } 1359 } 1360 1361 err = 0; 1362 for (nb = 0; nb + sizeof(hdr) <= count; ) { 1363 err = -EFAULT; 1364 if (__copy_from_user(&hdr, buf, sizeof(hdr))) 1365 break; 1366 1367 err = 0; 1368 if (nb + hdr.n_valid * HPTE_SIZE > count) 1369 break; 1370 1371 nb += sizeof(hdr); 1372 buf += sizeof(hdr); 1373 1374 err = -EINVAL; 1375 i = hdr.index; 1376 if (i >= kvm->arch.hpt_npte || 1377 i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte) 1378 break; 1379 1380 hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1381 lbuf = (unsigned long __user *)buf; 1382 for (j = 0; j < hdr.n_valid; ++j) { 1383 __be64 hpte_v; 1384 __be64 hpte_r; 1385 1386 err = -EFAULT; 1387 if (__get_user(hpte_v, lbuf) || 1388 __get_user(hpte_r, lbuf + 1)) 1389 goto out; 1390 v = be64_to_cpu(hpte_v); 1391 r = be64_to_cpu(hpte_r); 1392 err = -EINVAL; 1393 if (!(v & HPTE_V_VALID)) 1394 goto out; 1395 lbuf += 2; 1396 nb += HPTE_SIZE; 1397 1398 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) 1399 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1400 err = -EIO; 1401 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r, 1402 tmp); 1403 if (ret != H_SUCCESS) { 1404 pr_err("kvm_htab_write ret %ld i=%ld v=%lx " 1405 "r=%lx\n", ret, i, v, r); 1406 goto out; 1407 } 1408 if (!rma_setup && is_vrma_hpte(v)) { 1409 unsigned long psize = hpte_base_page_size(v, r); 1410 unsigned long senc = slb_pgsize_encoding(psize); 1411 unsigned long lpcr; 1412 1413 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T | 1414 (VRMA_VSID << SLB_VSID_SHIFT_1T); 1415 lpcr = senc << (LPCR_VRMASD_SH - 4); 1416 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD); 1417 rma_setup = 1; 1418 } 1419 ++i; 1420 hptp += 2; 1421 } 1422 1423 for (j = 0; j < hdr.n_invalid; ++j) { 1424 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) 1425 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1426 ++i; 1427 hptp += 2; 1428 } 1429 err = 0; 1430 } 1431 1432 out: 1433 /* Order HPTE updates vs. rma_setup_done */ 1434 smp_wmb(); 1435 kvm->arch.rma_setup_done = rma_setup; 1436 mutex_unlock(&kvm->lock); 1437 1438 if (err) 1439 return err; 1440 return nb; 1441 } 1442 1443 static int kvm_htab_release(struct inode *inode, struct file *filp) 1444 { 1445 struct kvm_htab_ctx *ctx = filp->private_data; 1446 1447 filp->private_data = NULL; 1448 if (!(ctx->flags & KVM_GET_HTAB_WRITE)) 1449 atomic_dec(&ctx->kvm->arch.hpte_mod_interest); 1450 kvm_put_kvm(ctx->kvm); 1451 kfree(ctx); 1452 return 0; 1453 } 1454 1455 static const struct file_operations kvm_htab_fops = { 1456 .read = kvm_htab_read, 1457 .write = kvm_htab_write, 1458 .llseek = default_llseek, 1459 .release = kvm_htab_release, 1460 }; 1461 1462 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf) 1463 { 1464 int ret; 1465 struct kvm_htab_ctx *ctx; 1466 int rwflag; 1467 1468 /* reject flags we don't recognize */ 1469 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE)) 1470 return -EINVAL; 1471 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 1472 if (!ctx) 1473 return -ENOMEM; 1474 kvm_get_kvm(kvm); 1475 ctx->kvm = kvm; 1476 ctx->index = ghf->start_index; 1477 ctx->flags = ghf->flags; 1478 ctx->first_pass = 1; 1479 1480 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY; 1481 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC); 1482 if (ret < 0) { 1483 kvm_put_kvm(kvm); 1484 return ret; 1485 } 1486 1487 if (rwflag == O_RDONLY) { 1488 mutex_lock(&kvm->slots_lock); 1489 atomic_inc(&kvm->arch.hpte_mod_interest); 1490 /* make sure kvmppc_do_h_enter etc. see the increment */ 1491 synchronize_srcu_expedited(&kvm->srcu); 1492 mutex_unlock(&kvm->slots_lock); 1493 } 1494 1495 return ret; 1496 } 1497 1498 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) 1499 { 1500 struct kvmppc_mmu *mmu = &vcpu->arch.mmu; 1501 1502 vcpu->arch.slb_nr = 32; /* POWER7/POWER8 */ 1503 1504 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate; 1505 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr; 1506 1507 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; 1508 } 1509