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 #include <linux/debugfs.h> 31 32 #include <asm/tlbflush.h> 33 #include <asm/kvm_ppc.h> 34 #include <asm/kvm_book3s.h> 35 #include <asm/mmu-hash64.h> 36 #include <asm/hvcall.h> 37 #include <asm/synch.h> 38 #include <asm/ppc-opcode.h> 39 #include <asm/cputable.h> 40 41 #include "trace_hv.h" 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(1ul << (order - PAGE_SHIFT)); 66 if (page) { 67 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page)); 68 memset((void *)hpt, 0, (1ul << order)); 69 kvm->arch.hpt_cma_alloc = 1; 70 } 71 72 /* Lastly try successively smaller sizes from the page allocator */ 73 /* Only do this if userspace didn't specify a size via ioctl */ 74 while (!hpt && order > PPC_MIN_HPT_ORDER && !htab_orderp) { 75 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT| 76 __GFP_NOWARN, order - PAGE_SHIFT); 77 if (!hpt) 78 --order; 79 } 80 81 if (!hpt) 82 return -ENOMEM; 83 84 kvm->arch.hpt_virt = hpt; 85 kvm->arch.hpt_order = order; 86 /* HPTEs are 2**4 bytes long */ 87 kvm->arch.hpt_npte = 1ul << (order - 4); 88 /* 128 (2**7) bytes in each HPTEG */ 89 kvm->arch.hpt_mask = (1ul << (order - 7)) - 1; 90 91 /* Allocate reverse map array */ 92 rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte); 93 if (!rev) { 94 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n"); 95 goto out_freehpt; 96 } 97 kvm->arch.revmap = rev; 98 kvm->arch.sdr1 = __pa(hpt) | (order - 18); 99 100 pr_info("KVM guest htab at %lx (order %ld), LPID %x\n", 101 hpt, order, kvm->arch.lpid); 102 103 if (htab_orderp) 104 *htab_orderp = order; 105 return 0; 106 107 out_freehpt: 108 if (kvm->arch.hpt_cma_alloc) 109 kvm_release_hpt(page, 1 << (order - PAGE_SHIFT)); 110 else 111 free_pages(hpt, order - PAGE_SHIFT); 112 return -ENOMEM; 113 } 114 115 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp) 116 { 117 long err = -EBUSY; 118 long order; 119 120 mutex_lock(&kvm->lock); 121 if (kvm->arch.hpte_setup_done) { 122 kvm->arch.hpte_setup_done = 0; 123 /* order hpte_setup_done vs. vcpus_running */ 124 smp_mb(); 125 if (atomic_read(&kvm->arch.vcpus_running)) { 126 kvm->arch.hpte_setup_done = 1; 127 goto out; 128 } 129 } 130 if (kvm->arch.hpt_virt) { 131 order = kvm->arch.hpt_order; 132 /* Set the entire HPT to 0, i.e. invalid HPTEs */ 133 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order); 134 /* 135 * Reset all the reverse-mapping chains for all memslots 136 */ 137 kvmppc_rmap_reset(kvm); 138 /* Ensure that each vcpu will flush its TLB on next entry. */ 139 cpumask_setall(&kvm->arch.need_tlb_flush); 140 *htab_orderp = order; 141 err = 0; 142 } else { 143 err = kvmppc_alloc_hpt(kvm, htab_orderp); 144 order = *htab_orderp; 145 } 146 out: 147 mutex_unlock(&kvm->lock); 148 return err; 149 } 150 151 void kvmppc_free_hpt(struct kvm *kvm) 152 { 153 kvmppc_free_lpid(kvm->arch.lpid); 154 vfree(kvm->arch.revmap); 155 if (kvm->arch.hpt_cma_alloc) 156 kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt), 157 1 << (kvm->arch.hpt_order - PAGE_SHIFT)); 158 else 159 free_pages(kvm->arch.hpt_virt, 160 kvm->arch.hpt_order - PAGE_SHIFT); 161 } 162 163 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */ 164 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize) 165 { 166 return (pgsize > 0x1000) ? HPTE_V_LARGE : 0; 167 } 168 169 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */ 170 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize) 171 { 172 return (pgsize == 0x10000) ? 0x1000 : 0; 173 } 174 175 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, 176 unsigned long porder) 177 { 178 unsigned long i; 179 unsigned long npages; 180 unsigned long hp_v, hp_r; 181 unsigned long addr, hash; 182 unsigned long psize; 183 unsigned long hp0, hp1; 184 unsigned long idx_ret; 185 long ret; 186 struct kvm *kvm = vcpu->kvm; 187 188 psize = 1ul << porder; 189 npages = memslot->npages >> (porder - PAGE_SHIFT); 190 191 /* VRMA can't be > 1TB */ 192 if (npages > 1ul << (40 - porder)) 193 npages = 1ul << (40 - porder); 194 /* Can't use more than 1 HPTE per HPTEG */ 195 if (npages > kvm->arch.hpt_mask + 1) 196 npages = kvm->arch.hpt_mask + 1; 197 198 hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) | 199 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize); 200 hp1 = hpte1_pgsize_encoding(psize) | 201 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX; 202 203 for (i = 0; i < npages; ++i) { 204 addr = i << porder; 205 /* can't use hpt_hash since va > 64 bits */ 206 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask; 207 /* 208 * We assume that the hash table is empty and no 209 * vcpus are using it at this stage. Since we create 210 * at most one HPTE per HPTEG, we just assume entry 7 211 * is available and use it. 212 */ 213 hash = (hash << 3) + 7; 214 hp_v = hp0 | ((addr >> 16) & ~0x7fUL); 215 hp_r = hp1 | addr; 216 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r, 217 &idx_ret); 218 if (ret != H_SUCCESS) { 219 pr_err("KVM: map_vrma at %lx failed, ret=%ld\n", 220 addr, ret); 221 break; 222 } 223 } 224 } 225 226 int kvmppc_mmu_hv_init(void) 227 { 228 unsigned long host_lpid, rsvd_lpid; 229 230 if (!cpu_has_feature(CPU_FTR_HVMODE)) 231 return -EINVAL; 232 233 /* POWER7 has 10-bit LPIDs (12-bit in POWER8) */ 234 host_lpid = mfspr(SPRN_LPID); 235 rsvd_lpid = LPID_RSVD; 236 237 kvmppc_init_lpid(rsvd_lpid + 1); 238 239 kvmppc_claim_lpid(host_lpid); 240 /* rsvd_lpid is reserved for use in partition switching */ 241 kvmppc_claim_lpid(rsvd_lpid); 242 243 return 0; 244 } 245 246 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu) 247 { 248 unsigned long msr = vcpu->arch.intr_msr; 249 250 /* If transactional, change to suspend mode on IRQ delivery */ 251 if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr)) 252 msr |= MSR_TS_S; 253 else 254 msr |= vcpu->arch.shregs.msr & MSR_TS_MASK; 255 kvmppc_set_msr(vcpu, msr); 256 } 257 258 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, 259 long pte_index, unsigned long pteh, 260 unsigned long ptel, unsigned long *pte_idx_ret) 261 { 262 long ret; 263 264 /* Protect linux PTE lookup from page table destruction */ 265 rcu_read_lock_sched(); /* this disables preemption too */ 266 ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel, 267 current->mm->pgd, false, pte_idx_ret); 268 rcu_read_unlock_sched(); 269 if (ret == H_TOO_HARD) { 270 /* this can't happen */ 271 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n"); 272 ret = H_RESOURCE; /* or something */ 273 } 274 return ret; 275 276 } 277 278 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu, 279 gva_t eaddr) 280 { 281 u64 mask; 282 int i; 283 284 for (i = 0; i < vcpu->arch.slb_nr; i++) { 285 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V)) 286 continue; 287 288 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T) 289 mask = ESID_MASK_1T; 290 else 291 mask = ESID_MASK; 292 293 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0) 294 return &vcpu->arch.slb[i]; 295 } 296 return NULL; 297 } 298 299 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r, 300 unsigned long ea) 301 { 302 unsigned long ra_mask; 303 304 ra_mask = hpte_page_size(v, r) - 1; 305 return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask); 306 } 307 308 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, 309 struct kvmppc_pte *gpte, bool data, bool iswrite) 310 { 311 struct kvm *kvm = vcpu->kvm; 312 struct kvmppc_slb *slbe; 313 unsigned long slb_v; 314 unsigned long pp, key; 315 unsigned long v, gr; 316 __be64 *hptep; 317 int index; 318 int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR); 319 320 /* Get SLB entry */ 321 if (virtmode) { 322 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr); 323 if (!slbe) 324 return -EINVAL; 325 slb_v = slbe->origv; 326 } else { 327 /* real mode access */ 328 slb_v = vcpu->kvm->arch.vrma_slb_v; 329 } 330 331 preempt_disable(); 332 /* Find the HPTE in the hash table */ 333 index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, 334 HPTE_V_VALID | HPTE_V_ABSENT); 335 if (index < 0) { 336 preempt_enable(); 337 return -ENOENT; 338 } 339 hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4)); 340 v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK; 341 gr = kvm->arch.revmap[index].guest_rpte; 342 343 unlock_hpte(hptep, 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 unlock_hpte(hptep, hpte[0]); 473 preempt_enable(); 474 475 if (hpte[0] != vcpu->arch.pgfault_hpte[0] || 476 hpte[1] != vcpu->arch.pgfault_hpte[1]) 477 return RESUME_GUEST; 478 479 /* Translate the logical address and get the page */ 480 psize = hpte_page_size(hpte[0], r); 481 gpa_base = r & HPTE_R_RPN & ~(psize - 1); 482 gfn_base = gpa_base >> PAGE_SHIFT; 483 gpa = gpa_base | (ea & (psize - 1)); 484 gfn = gpa >> PAGE_SHIFT; 485 memslot = gfn_to_memslot(kvm, gfn); 486 487 trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr); 488 489 /* No memslot means it's an emulated MMIO region */ 490 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 491 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, 492 dsisr & DSISR_ISSTORE); 493 494 /* 495 * This should never happen, because of the slot_is_aligned() 496 * check in kvmppc_do_h_enter(). 497 */ 498 if (gfn_base < memslot->base_gfn) 499 return -EFAULT; 500 501 /* used to check for invalidations in progress */ 502 mmu_seq = kvm->mmu_notifier_seq; 503 smp_rmb(); 504 505 ret = -EFAULT; 506 is_io = 0; 507 pfn = 0; 508 page = NULL; 509 pte_size = PAGE_SIZE; 510 writing = (dsisr & DSISR_ISSTORE) != 0; 511 /* If writing != 0, then the HPTE must allow writing, if we get here */ 512 write_ok = writing; 513 hva = gfn_to_hva_memslot(memslot, gfn); 514 npages = get_user_pages_fast(hva, 1, writing, pages); 515 if (npages < 1) { 516 /* Check if it's an I/O mapping */ 517 down_read(¤t->mm->mmap_sem); 518 vma = find_vma(current->mm, hva); 519 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end && 520 (vma->vm_flags & VM_PFNMAP)) { 521 pfn = vma->vm_pgoff + 522 ((hva - vma->vm_start) >> PAGE_SHIFT); 523 pte_size = psize; 524 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot)); 525 write_ok = vma->vm_flags & VM_WRITE; 526 } 527 up_read(¤t->mm->mmap_sem); 528 if (!pfn) 529 goto out_put; 530 } else { 531 page = pages[0]; 532 pfn = page_to_pfn(page); 533 if (PageHuge(page)) { 534 page = compound_head(page); 535 pte_size <<= compound_order(page); 536 } 537 /* if the guest wants write access, see if that is OK */ 538 if (!writing && hpte_is_writable(r)) { 539 pte_t *ptep, pte; 540 unsigned long flags; 541 /* 542 * We need to protect against page table destruction 543 * hugepage split and collapse. 544 */ 545 local_irq_save(flags); 546 ptep = find_linux_pte_or_hugepte(current->mm->pgd, 547 hva, NULL, NULL); 548 if (ptep) { 549 pte = kvmppc_read_update_linux_pte(ptep, 1); 550 if (pte_write(pte)) 551 write_ok = 1; 552 } 553 local_irq_restore(flags); 554 } 555 } 556 557 if (psize > pte_size) 558 goto out_put; 559 560 /* Check WIMG vs. the actual page we're accessing */ 561 if (!hpte_cache_flags_ok(r, is_io)) { 562 if (is_io) 563 goto out_put; 564 565 /* 566 * Allow guest to map emulated device memory as 567 * uncacheable, but actually make it cacheable. 568 */ 569 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M; 570 } 571 572 /* 573 * Set the HPTE to point to pfn. 574 * Since the pfn is at PAGE_SIZE granularity, make sure we 575 * don't mask out lower-order bits if psize < PAGE_SIZE. 576 */ 577 if (psize < PAGE_SIZE) 578 psize = PAGE_SIZE; 579 r = (r & ~(HPTE_R_PP0 - psize)) | ((pfn << PAGE_SHIFT) & ~(psize - 1)); 580 if (hpte_is_writable(r) && !write_ok) 581 r = hpte_make_readonly(r); 582 ret = RESUME_GUEST; 583 preempt_disable(); 584 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) 585 cpu_relax(); 586 if ((be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK) != hpte[0] || 587 be64_to_cpu(hptep[1]) != hpte[1] || 588 rev->guest_rpte != hpte[2]) 589 /* HPTE has been changed under us; let the guest retry */ 590 goto out_unlock; 591 hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; 592 593 /* Always put the HPTE in the rmap chain for the page base address */ 594 rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn]; 595 lock_rmap(rmap); 596 597 /* Check if we might have been invalidated; let the guest retry if so */ 598 ret = RESUME_GUEST; 599 if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) { 600 unlock_rmap(rmap); 601 goto out_unlock; 602 } 603 604 /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */ 605 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT; 606 r &= rcbits | ~(HPTE_R_R | HPTE_R_C); 607 608 if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) { 609 /* HPTE was previously valid, so we need to invalidate it */ 610 unlock_rmap(rmap); 611 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT); 612 kvmppc_invalidate_hpte(kvm, hptep, index); 613 /* don't lose previous R and C bits */ 614 r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C); 615 } else { 616 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0); 617 } 618 619 hptep[1] = cpu_to_be64(r); 620 eieio(); 621 __unlock_hpte(hptep, hpte[0]); 622 asm volatile("ptesync" : : : "memory"); 623 preempt_enable(); 624 if (page && hpte_is_writable(r)) 625 SetPageDirty(page); 626 627 out_put: 628 trace_kvm_page_fault_exit(vcpu, hpte, ret); 629 630 if (page) { 631 /* 632 * We drop pages[0] here, not page because page might 633 * have been set to the head page of a compound, but 634 * we have to drop the reference on the correct tail 635 * page to match the get inside gup() 636 */ 637 put_page(pages[0]); 638 } 639 return ret; 640 641 out_unlock: 642 __unlock_hpte(hptep, be64_to_cpu(hptep[0])); 643 preempt_enable(); 644 goto out_put; 645 } 646 647 static void kvmppc_rmap_reset(struct kvm *kvm) 648 { 649 struct kvm_memslots *slots; 650 struct kvm_memory_slot *memslot; 651 int srcu_idx; 652 653 srcu_idx = srcu_read_lock(&kvm->srcu); 654 slots = kvm_memslots(kvm); 655 kvm_for_each_memslot(memslot, slots) { 656 /* 657 * This assumes it is acceptable to lose reference and 658 * change bits across a reset. 659 */ 660 memset(memslot->arch.rmap, 0, 661 memslot->npages * sizeof(*memslot->arch.rmap)); 662 } 663 srcu_read_unlock(&kvm->srcu, srcu_idx); 664 } 665 666 static int kvm_handle_hva_range(struct kvm *kvm, 667 unsigned long start, 668 unsigned long end, 669 int (*handler)(struct kvm *kvm, 670 unsigned long *rmapp, 671 unsigned long gfn)) 672 { 673 int ret; 674 int retval = 0; 675 struct kvm_memslots *slots; 676 struct kvm_memory_slot *memslot; 677 678 slots = kvm_memslots(kvm); 679 kvm_for_each_memslot(memslot, slots) { 680 unsigned long hva_start, hva_end; 681 gfn_t gfn, gfn_end; 682 683 hva_start = max(start, memslot->userspace_addr); 684 hva_end = min(end, memslot->userspace_addr + 685 (memslot->npages << PAGE_SHIFT)); 686 if (hva_start >= hva_end) 687 continue; 688 /* 689 * {gfn(page) | page intersects with [hva_start, hva_end)} = 690 * {gfn, gfn+1, ..., gfn_end-1}. 691 */ 692 gfn = hva_to_gfn_memslot(hva_start, memslot); 693 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot); 694 695 for (; gfn < gfn_end; ++gfn) { 696 gfn_t gfn_offset = gfn - memslot->base_gfn; 697 698 ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn); 699 retval |= ret; 700 } 701 } 702 703 return retval; 704 } 705 706 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, 707 int (*handler)(struct kvm *kvm, unsigned long *rmapp, 708 unsigned long gfn)) 709 { 710 return kvm_handle_hva_range(kvm, hva, hva + 1, handler); 711 } 712 713 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, 714 unsigned long gfn) 715 { 716 struct revmap_entry *rev = kvm->arch.revmap; 717 unsigned long h, i, j; 718 __be64 *hptep; 719 unsigned long ptel, psize, rcbits; 720 721 for (;;) { 722 lock_rmap(rmapp); 723 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 724 unlock_rmap(rmapp); 725 break; 726 } 727 728 /* 729 * To avoid an ABBA deadlock with the HPTE lock bit, 730 * we can't spin on the HPTE lock while holding the 731 * rmap chain lock. 732 */ 733 i = *rmapp & KVMPPC_RMAP_INDEX; 734 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4)); 735 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 736 /* unlock rmap before spinning on the HPTE lock */ 737 unlock_rmap(rmapp); 738 while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK) 739 cpu_relax(); 740 continue; 741 } 742 j = rev[i].forw; 743 if (j == i) { 744 /* chain is now empty */ 745 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX); 746 } else { 747 /* remove i from chain */ 748 h = rev[i].back; 749 rev[h].forw = j; 750 rev[j].back = h; 751 rev[i].forw = rev[i].back = i; 752 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j; 753 } 754 755 /* Now check and modify the HPTE */ 756 ptel = rev[i].guest_rpte; 757 psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel); 758 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) && 759 hpte_rpn(ptel, psize) == gfn) { 760 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT); 761 kvmppc_invalidate_hpte(kvm, hptep, i); 762 /* Harvest R and C */ 763 rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C); 764 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT; 765 if (rcbits & HPTE_R_C) 766 kvmppc_update_rmap_change(rmapp, psize); 767 if (rcbits & ~rev[i].guest_rpte) { 768 rev[i].guest_rpte = ptel | rcbits; 769 note_hpte_modification(kvm, &rev[i]); 770 } 771 } 772 unlock_rmap(rmapp); 773 __unlock_hpte(hptep, be64_to_cpu(hptep[0])); 774 } 775 return 0; 776 } 777 778 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva) 779 { 780 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 781 return 0; 782 } 783 784 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end) 785 { 786 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp); 787 return 0; 788 } 789 790 void kvmppc_core_flush_memslot_hv(struct kvm *kvm, 791 struct kvm_memory_slot *memslot) 792 { 793 unsigned long *rmapp; 794 unsigned long gfn; 795 unsigned long n; 796 797 rmapp = memslot->arch.rmap; 798 gfn = memslot->base_gfn; 799 for (n = memslot->npages; n; --n) { 800 /* 801 * Testing the present bit without locking is OK because 802 * the memslot has been marked invalid already, and hence 803 * no new HPTEs referencing this page can be created, 804 * thus the present bit can't go from 0 to 1. 805 */ 806 if (*rmapp & KVMPPC_RMAP_PRESENT) 807 kvm_unmap_rmapp(kvm, rmapp, gfn); 808 ++rmapp; 809 ++gfn; 810 } 811 } 812 813 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 814 unsigned long gfn) 815 { 816 struct revmap_entry *rev = kvm->arch.revmap; 817 unsigned long head, i, j; 818 __be64 *hptep; 819 int ret = 0; 820 821 retry: 822 lock_rmap(rmapp); 823 if (*rmapp & KVMPPC_RMAP_REFERENCED) { 824 *rmapp &= ~KVMPPC_RMAP_REFERENCED; 825 ret = 1; 826 } 827 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 828 unlock_rmap(rmapp); 829 return ret; 830 } 831 832 i = head = *rmapp & KVMPPC_RMAP_INDEX; 833 do { 834 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4)); 835 j = rev[i].forw; 836 837 /* If this HPTE isn't referenced, ignore it */ 838 if (!(be64_to_cpu(hptep[1]) & HPTE_R_R)) 839 continue; 840 841 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { 842 /* unlock rmap before spinning on the HPTE lock */ 843 unlock_rmap(rmapp); 844 while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK) 845 cpu_relax(); 846 goto retry; 847 } 848 849 /* Now check and modify the HPTE */ 850 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) && 851 (be64_to_cpu(hptep[1]) & HPTE_R_R)) { 852 kvmppc_clear_ref_hpte(kvm, hptep, i); 853 if (!(rev[i].guest_rpte & HPTE_R_R)) { 854 rev[i].guest_rpte |= HPTE_R_R; 855 note_hpte_modification(kvm, &rev[i]); 856 } 857 ret = 1; 858 } 859 __unlock_hpte(hptep, be64_to_cpu(hptep[0])); 860 } while ((i = j) != head); 861 862 unlock_rmap(rmapp); 863 return ret; 864 } 865 866 int kvm_age_hva_hv(struct kvm *kvm, unsigned long start, unsigned long end) 867 { 868 return kvm_handle_hva_range(kvm, start, end, kvm_age_rmapp); 869 } 870 871 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, 872 unsigned long gfn) 873 { 874 struct revmap_entry *rev = kvm->arch.revmap; 875 unsigned long head, i, j; 876 unsigned long *hp; 877 int ret = 1; 878 879 if (*rmapp & KVMPPC_RMAP_REFERENCED) 880 return 1; 881 882 lock_rmap(rmapp); 883 if (*rmapp & KVMPPC_RMAP_REFERENCED) 884 goto out; 885 886 if (*rmapp & KVMPPC_RMAP_PRESENT) { 887 i = head = *rmapp & KVMPPC_RMAP_INDEX; 888 do { 889 hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4)); 890 j = rev[i].forw; 891 if (be64_to_cpu(hp[1]) & HPTE_R_R) 892 goto out; 893 } while ((i = j) != head); 894 } 895 ret = 0; 896 897 out: 898 unlock_rmap(rmapp); 899 return ret; 900 } 901 902 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva) 903 { 904 return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp); 905 } 906 907 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte) 908 { 909 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); 910 } 911 912 static int vcpus_running(struct kvm *kvm) 913 { 914 return atomic_read(&kvm->arch.vcpus_running) != 0; 915 } 916 917 /* 918 * Returns the number of system pages that are dirty. 919 * This can be more than 1 if we find a huge-page HPTE. 920 */ 921 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp) 922 { 923 struct revmap_entry *rev = kvm->arch.revmap; 924 unsigned long head, i, j; 925 unsigned long n; 926 unsigned long v, r; 927 __be64 *hptep; 928 int npages_dirty = 0; 929 930 retry: 931 lock_rmap(rmapp); 932 if (*rmapp & KVMPPC_RMAP_CHANGED) { 933 long change_order = (*rmapp & KVMPPC_RMAP_CHG_ORDER) 934 >> KVMPPC_RMAP_CHG_SHIFT; 935 *rmapp &= ~(KVMPPC_RMAP_CHANGED | KVMPPC_RMAP_CHG_ORDER); 936 npages_dirty = 1; 937 if (change_order > PAGE_SHIFT) 938 npages_dirty = 1ul << (change_order - PAGE_SHIFT); 939 } 940 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { 941 unlock_rmap(rmapp); 942 return npages_dirty; 943 } 944 945 i = head = *rmapp & KVMPPC_RMAP_INDEX; 946 do { 947 unsigned long hptep1; 948 hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4)); 949 j = rev[i].forw; 950 951 /* 952 * Checking the C (changed) bit here is racy since there 953 * is no guarantee about when the hardware writes it back. 954 * If the HPTE is not writable then it is stable since the 955 * page can't be written to, and we would have done a tlbie 956 * (which forces the hardware to complete any writeback) 957 * when making the HPTE read-only. 958 * If vcpus are running then this call is racy anyway 959 * since the page could get dirtied subsequently, so we 960 * expect there to be a further call which would pick up 961 * any delayed C bit writeback. 962 * Otherwise we need to do the tlbie even if C==0 in 963 * order to pick up any delayed writeback of C. 964 */ 965 hptep1 = be64_to_cpu(hptep[1]); 966 if (!(hptep1 & HPTE_R_C) && 967 (!hpte_is_writable(hptep1) || vcpus_running(kvm))) 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] & cpu_to_be64(HPTE_V_HVLOCK)) 974 cpu_relax(); 975 goto retry; 976 } 977 978 /* Now check and modify the HPTE */ 979 if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) { 980 __unlock_hpte(hptep, be64_to_cpu(hptep[0])); 981 continue; 982 } 983 984 /* need to make it temporarily absent so C is stable */ 985 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT); 986 kvmppc_invalidate_hpte(kvm, hptep, i); 987 v = be64_to_cpu(hptep[0]); 988 r = be64_to_cpu(hptep[1]); 989 if (r & HPTE_R_C) { 990 hptep[1] = cpu_to_be64(r & ~HPTE_R_C); 991 if (!(rev[i].guest_rpte & HPTE_R_C)) { 992 rev[i].guest_rpte |= HPTE_R_C; 993 note_hpte_modification(kvm, &rev[i]); 994 } 995 n = hpte_page_size(v, r); 996 n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT; 997 if (n > npages_dirty) 998 npages_dirty = n; 999 eieio(); 1000 } 1001 v &= ~HPTE_V_ABSENT; 1002 v |= HPTE_V_VALID; 1003 __unlock_hpte(hptep, v); 1004 } while ((i = j) != head); 1005 1006 unlock_rmap(rmapp); 1007 return npages_dirty; 1008 } 1009 1010 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, 1011 struct kvm_memory_slot *memslot, 1012 unsigned long *map) 1013 { 1014 unsigned long gfn; 1015 1016 if (!vpa->dirty || !vpa->pinned_addr) 1017 return; 1018 gfn = vpa->gpa >> PAGE_SHIFT; 1019 if (gfn < memslot->base_gfn || 1020 gfn >= memslot->base_gfn + memslot->npages) 1021 return; 1022 1023 vpa->dirty = false; 1024 if (map) 1025 __set_bit_le(gfn - memslot->base_gfn, map); 1026 } 1027 1028 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, 1029 unsigned long *map) 1030 { 1031 unsigned long i, j; 1032 unsigned long *rmapp; 1033 struct kvm_vcpu *vcpu; 1034 1035 preempt_disable(); 1036 rmapp = memslot->arch.rmap; 1037 for (i = 0; i < memslot->npages; ++i) { 1038 int npages = kvm_test_clear_dirty_npages(kvm, rmapp); 1039 /* 1040 * Note that if npages > 0 then i must be a multiple of npages, 1041 * since we always put huge-page HPTEs in the rmap chain 1042 * corresponding to their page base address. 1043 */ 1044 if (npages && map) 1045 for (j = i; npages; ++j, --npages) 1046 __set_bit_le(j, map); 1047 ++rmapp; 1048 } 1049 1050 /* Harvest dirty bits from VPA and DTL updates */ 1051 /* Note: we never modify the SLB shadow buffer areas */ 1052 kvm_for_each_vcpu(i, vcpu, kvm) { 1053 spin_lock(&vcpu->arch.vpa_update_lock); 1054 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map); 1055 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map); 1056 spin_unlock(&vcpu->arch.vpa_update_lock); 1057 } 1058 preempt_enable(); 1059 return 0; 1060 } 1061 1062 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, 1063 unsigned long *nb_ret) 1064 { 1065 struct kvm_memory_slot *memslot; 1066 unsigned long gfn = gpa >> PAGE_SHIFT; 1067 struct page *page, *pages[1]; 1068 int npages; 1069 unsigned long hva, offset; 1070 int srcu_idx; 1071 1072 srcu_idx = srcu_read_lock(&kvm->srcu); 1073 memslot = gfn_to_memslot(kvm, gfn); 1074 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) 1075 goto err; 1076 hva = gfn_to_hva_memslot(memslot, gfn); 1077 npages = get_user_pages_fast(hva, 1, 1, pages); 1078 if (npages < 1) 1079 goto err; 1080 page = pages[0]; 1081 srcu_read_unlock(&kvm->srcu, srcu_idx); 1082 1083 offset = gpa & (PAGE_SIZE - 1); 1084 if (nb_ret) 1085 *nb_ret = PAGE_SIZE - offset; 1086 return page_address(page) + offset; 1087 1088 err: 1089 srcu_read_unlock(&kvm->srcu, srcu_idx); 1090 return NULL; 1091 } 1092 1093 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa, 1094 bool dirty) 1095 { 1096 struct page *page = virt_to_page(va); 1097 struct kvm_memory_slot *memslot; 1098 unsigned long gfn; 1099 unsigned long *rmap; 1100 int srcu_idx; 1101 1102 put_page(page); 1103 1104 if (!dirty) 1105 return; 1106 1107 /* We need to mark this page dirty in the rmap chain */ 1108 gfn = gpa >> PAGE_SHIFT; 1109 srcu_idx = srcu_read_lock(&kvm->srcu); 1110 memslot = gfn_to_memslot(kvm, gfn); 1111 if (memslot) { 1112 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn]; 1113 lock_rmap(rmap); 1114 *rmap |= KVMPPC_RMAP_CHANGED; 1115 unlock_rmap(rmap); 1116 } 1117 srcu_read_unlock(&kvm->srcu, srcu_idx); 1118 } 1119 1120 /* 1121 * Functions for reading and writing the hash table via reads and 1122 * writes on a file descriptor. 1123 * 1124 * Reads return the guest view of the hash table, which has to be 1125 * pieced together from the real hash table and the guest_rpte 1126 * values in the revmap array. 1127 * 1128 * On writes, each HPTE written is considered in turn, and if it 1129 * is valid, it is written to the HPT as if an H_ENTER with the 1130 * exact flag set was done. When the invalid count is non-zero 1131 * in the header written to the stream, the kernel will make 1132 * sure that that many HPTEs are invalid, and invalidate them 1133 * if not. 1134 */ 1135 1136 struct kvm_htab_ctx { 1137 unsigned long index; 1138 unsigned long flags; 1139 struct kvm *kvm; 1140 int first_pass; 1141 }; 1142 1143 #define HPTE_SIZE (2 * sizeof(unsigned long)) 1144 1145 /* 1146 * Returns 1 if this HPT entry has been modified or has pending 1147 * R/C bit changes. 1148 */ 1149 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp) 1150 { 1151 unsigned long rcbits_unset; 1152 1153 if (revp->guest_rpte & HPTE_GR_MODIFIED) 1154 return 1; 1155 1156 /* Also need to consider changes in reference and changed bits */ 1157 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1158 if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) && 1159 (be64_to_cpu(hptp[1]) & rcbits_unset)) 1160 return 1; 1161 1162 return 0; 1163 } 1164 1165 static long record_hpte(unsigned long flags, __be64 *hptp, 1166 unsigned long *hpte, struct revmap_entry *revp, 1167 int want_valid, int first_pass) 1168 { 1169 unsigned long v, r; 1170 unsigned long rcbits_unset; 1171 int ok = 1; 1172 int valid, dirty; 1173 1174 /* Unmodified entries are uninteresting except on the first pass */ 1175 dirty = hpte_dirty(revp, hptp); 1176 if (!first_pass && !dirty) 1177 return 0; 1178 1179 valid = 0; 1180 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) { 1181 valid = 1; 1182 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && 1183 !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED)) 1184 valid = 0; 1185 } 1186 if (valid != want_valid) 1187 return 0; 1188 1189 v = r = 0; 1190 if (valid || dirty) { 1191 /* lock the HPTE so it's stable and read it */ 1192 preempt_disable(); 1193 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) 1194 cpu_relax(); 1195 v = be64_to_cpu(hptp[0]); 1196 1197 /* re-evaluate valid and dirty from synchronized HPTE value */ 1198 valid = !!(v & HPTE_V_VALID); 1199 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); 1200 1201 /* Harvest R and C into guest view if necessary */ 1202 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); 1203 if (valid && (rcbits_unset & be64_to_cpu(hptp[1]))) { 1204 revp->guest_rpte |= (be64_to_cpu(hptp[1]) & 1205 (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED; 1206 dirty = 1; 1207 } 1208 1209 if (v & HPTE_V_ABSENT) { 1210 v &= ~HPTE_V_ABSENT; 1211 v |= HPTE_V_VALID; 1212 valid = 1; 1213 } 1214 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) 1215 valid = 0; 1216 1217 r = revp->guest_rpte; 1218 /* only clear modified if this is the right sort of entry */ 1219 if (valid == want_valid && dirty) { 1220 r &= ~HPTE_GR_MODIFIED; 1221 revp->guest_rpte = r; 1222 } 1223 unlock_hpte(hptp, be64_to_cpu(hptp[0])); 1224 preempt_enable(); 1225 if (!(valid == want_valid && (first_pass || dirty))) 1226 ok = 0; 1227 } 1228 hpte[0] = cpu_to_be64(v); 1229 hpte[1] = cpu_to_be64(r); 1230 return ok; 1231 } 1232 1233 static ssize_t kvm_htab_read(struct file *file, char __user *buf, 1234 size_t count, loff_t *ppos) 1235 { 1236 struct kvm_htab_ctx *ctx = file->private_data; 1237 struct kvm *kvm = ctx->kvm; 1238 struct kvm_get_htab_header hdr; 1239 __be64 *hptp; 1240 struct revmap_entry *revp; 1241 unsigned long i, nb, nw; 1242 unsigned long __user *lbuf; 1243 struct kvm_get_htab_header __user *hptr; 1244 unsigned long flags; 1245 int first_pass; 1246 unsigned long hpte[2]; 1247 1248 if (!access_ok(VERIFY_WRITE, buf, count)) 1249 return -EFAULT; 1250 1251 first_pass = ctx->first_pass; 1252 flags = ctx->flags; 1253 1254 i = ctx->index; 1255 hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1256 revp = kvm->arch.revmap + i; 1257 lbuf = (unsigned long __user *)buf; 1258 1259 nb = 0; 1260 while (nb + sizeof(hdr) + HPTE_SIZE < count) { 1261 /* Initialize header */ 1262 hptr = (struct kvm_get_htab_header __user *)buf; 1263 hdr.n_valid = 0; 1264 hdr.n_invalid = 0; 1265 nw = nb; 1266 nb += sizeof(hdr); 1267 lbuf = (unsigned long __user *)(buf + sizeof(hdr)); 1268 1269 /* Skip uninteresting entries, i.e. clean on not-first pass */ 1270 if (!first_pass) { 1271 while (i < kvm->arch.hpt_npte && 1272 !hpte_dirty(revp, hptp)) { 1273 ++i; 1274 hptp += 2; 1275 ++revp; 1276 } 1277 } 1278 hdr.index = i; 1279 1280 /* Grab a series of valid entries */ 1281 while (i < kvm->arch.hpt_npte && 1282 hdr.n_valid < 0xffff && 1283 nb + HPTE_SIZE < count && 1284 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) { 1285 /* valid entry, write it out */ 1286 ++hdr.n_valid; 1287 if (__put_user(hpte[0], lbuf) || 1288 __put_user(hpte[1], lbuf + 1)) 1289 return -EFAULT; 1290 nb += HPTE_SIZE; 1291 lbuf += 2; 1292 ++i; 1293 hptp += 2; 1294 ++revp; 1295 } 1296 /* Now skip invalid entries while we can */ 1297 while (i < kvm->arch.hpt_npte && 1298 hdr.n_invalid < 0xffff && 1299 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) { 1300 /* found an invalid entry */ 1301 ++hdr.n_invalid; 1302 ++i; 1303 hptp += 2; 1304 ++revp; 1305 } 1306 1307 if (hdr.n_valid || hdr.n_invalid) { 1308 /* write back the header */ 1309 if (__copy_to_user(hptr, &hdr, sizeof(hdr))) 1310 return -EFAULT; 1311 nw = nb; 1312 buf = (char __user *)lbuf; 1313 } else { 1314 nb = nw; 1315 } 1316 1317 /* Check if we've wrapped around the hash table */ 1318 if (i >= kvm->arch.hpt_npte) { 1319 i = 0; 1320 ctx->first_pass = 0; 1321 break; 1322 } 1323 } 1324 1325 ctx->index = i; 1326 1327 return nb; 1328 } 1329 1330 static ssize_t kvm_htab_write(struct file *file, const char __user *buf, 1331 size_t count, loff_t *ppos) 1332 { 1333 struct kvm_htab_ctx *ctx = file->private_data; 1334 struct kvm *kvm = ctx->kvm; 1335 struct kvm_get_htab_header hdr; 1336 unsigned long i, j; 1337 unsigned long v, r; 1338 unsigned long __user *lbuf; 1339 __be64 *hptp; 1340 unsigned long tmp[2]; 1341 ssize_t nb; 1342 long int err, ret; 1343 int hpte_setup; 1344 1345 if (!access_ok(VERIFY_READ, buf, count)) 1346 return -EFAULT; 1347 1348 /* lock out vcpus from running while we're doing this */ 1349 mutex_lock(&kvm->lock); 1350 hpte_setup = kvm->arch.hpte_setup_done; 1351 if (hpte_setup) { 1352 kvm->arch.hpte_setup_done = 0; /* temporarily */ 1353 /* order hpte_setup_done vs. vcpus_running */ 1354 smp_mb(); 1355 if (atomic_read(&kvm->arch.vcpus_running)) { 1356 kvm->arch.hpte_setup_done = 1; 1357 mutex_unlock(&kvm->lock); 1358 return -EBUSY; 1359 } 1360 } 1361 1362 err = 0; 1363 for (nb = 0; nb + sizeof(hdr) <= count; ) { 1364 err = -EFAULT; 1365 if (__copy_from_user(&hdr, buf, sizeof(hdr))) 1366 break; 1367 1368 err = 0; 1369 if (nb + hdr.n_valid * HPTE_SIZE > count) 1370 break; 1371 1372 nb += sizeof(hdr); 1373 buf += sizeof(hdr); 1374 1375 err = -EINVAL; 1376 i = hdr.index; 1377 if (i >= kvm->arch.hpt_npte || 1378 i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte) 1379 break; 1380 1381 hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1382 lbuf = (unsigned long __user *)buf; 1383 for (j = 0; j < hdr.n_valid; ++j) { 1384 __be64 hpte_v; 1385 __be64 hpte_r; 1386 1387 err = -EFAULT; 1388 if (__get_user(hpte_v, lbuf) || 1389 __get_user(hpte_r, lbuf + 1)) 1390 goto out; 1391 v = be64_to_cpu(hpte_v); 1392 r = be64_to_cpu(hpte_r); 1393 err = -EINVAL; 1394 if (!(v & HPTE_V_VALID)) 1395 goto out; 1396 lbuf += 2; 1397 nb += HPTE_SIZE; 1398 1399 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) 1400 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1401 err = -EIO; 1402 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r, 1403 tmp); 1404 if (ret != H_SUCCESS) { 1405 pr_err("kvm_htab_write ret %ld i=%ld v=%lx " 1406 "r=%lx\n", ret, i, v, r); 1407 goto out; 1408 } 1409 if (!hpte_setup && is_vrma_hpte(v)) { 1410 unsigned long psize = hpte_base_page_size(v, r); 1411 unsigned long senc = slb_pgsize_encoding(psize); 1412 unsigned long lpcr; 1413 1414 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T | 1415 (VRMA_VSID << SLB_VSID_SHIFT_1T); 1416 lpcr = senc << (LPCR_VRMASD_SH - 4); 1417 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD); 1418 hpte_setup = 1; 1419 } 1420 ++i; 1421 hptp += 2; 1422 } 1423 1424 for (j = 0; j < hdr.n_invalid; ++j) { 1425 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) 1426 kvmppc_do_h_remove(kvm, 0, i, 0, tmp); 1427 ++i; 1428 hptp += 2; 1429 } 1430 err = 0; 1431 } 1432 1433 out: 1434 /* Order HPTE updates vs. hpte_setup_done */ 1435 smp_wmb(); 1436 kvm->arch.hpte_setup_done = hpte_setup; 1437 mutex_unlock(&kvm->lock); 1438 1439 if (err) 1440 return err; 1441 return nb; 1442 } 1443 1444 static int kvm_htab_release(struct inode *inode, struct file *filp) 1445 { 1446 struct kvm_htab_ctx *ctx = filp->private_data; 1447 1448 filp->private_data = NULL; 1449 if (!(ctx->flags & KVM_GET_HTAB_WRITE)) 1450 atomic_dec(&ctx->kvm->arch.hpte_mod_interest); 1451 kvm_put_kvm(ctx->kvm); 1452 kfree(ctx); 1453 return 0; 1454 } 1455 1456 static const struct file_operations kvm_htab_fops = { 1457 .read = kvm_htab_read, 1458 .write = kvm_htab_write, 1459 .llseek = default_llseek, 1460 .release = kvm_htab_release, 1461 }; 1462 1463 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf) 1464 { 1465 int ret; 1466 struct kvm_htab_ctx *ctx; 1467 int rwflag; 1468 1469 /* reject flags we don't recognize */ 1470 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE)) 1471 return -EINVAL; 1472 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 1473 if (!ctx) 1474 return -ENOMEM; 1475 kvm_get_kvm(kvm); 1476 ctx->kvm = kvm; 1477 ctx->index = ghf->start_index; 1478 ctx->flags = ghf->flags; 1479 ctx->first_pass = 1; 1480 1481 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY; 1482 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC); 1483 if (ret < 0) { 1484 kvm_put_kvm(kvm); 1485 return ret; 1486 } 1487 1488 if (rwflag == O_RDONLY) { 1489 mutex_lock(&kvm->slots_lock); 1490 atomic_inc(&kvm->arch.hpte_mod_interest); 1491 /* make sure kvmppc_do_h_enter etc. see the increment */ 1492 synchronize_srcu_expedited(&kvm->srcu); 1493 mutex_unlock(&kvm->slots_lock); 1494 } 1495 1496 return ret; 1497 } 1498 1499 struct debugfs_htab_state { 1500 struct kvm *kvm; 1501 struct mutex mutex; 1502 unsigned long hpt_index; 1503 int chars_left; 1504 int buf_index; 1505 char buf[64]; 1506 }; 1507 1508 static int debugfs_htab_open(struct inode *inode, struct file *file) 1509 { 1510 struct kvm *kvm = inode->i_private; 1511 struct debugfs_htab_state *p; 1512 1513 p = kzalloc(sizeof(*p), GFP_KERNEL); 1514 if (!p) 1515 return -ENOMEM; 1516 1517 kvm_get_kvm(kvm); 1518 p->kvm = kvm; 1519 mutex_init(&p->mutex); 1520 file->private_data = p; 1521 1522 return nonseekable_open(inode, file); 1523 } 1524 1525 static int debugfs_htab_release(struct inode *inode, struct file *file) 1526 { 1527 struct debugfs_htab_state *p = file->private_data; 1528 1529 kvm_put_kvm(p->kvm); 1530 kfree(p); 1531 return 0; 1532 } 1533 1534 static ssize_t debugfs_htab_read(struct file *file, char __user *buf, 1535 size_t len, loff_t *ppos) 1536 { 1537 struct debugfs_htab_state *p = file->private_data; 1538 ssize_t ret, r; 1539 unsigned long i, n; 1540 unsigned long v, hr, gr; 1541 struct kvm *kvm; 1542 __be64 *hptp; 1543 1544 ret = mutex_lock_interruptible(&p->mutex); 1545 if (ret) 1546 return ret; 1547 1548 if (p->chars_left) { 1549 n = p->chars_left; 1550 if (n > len) 1551 n = len; 1552 r = copy_to_user(buf, p->buf + p->buf_index, n); 1553 n -= r; 1554 p->chars_left -= n; 1555 p->buf_index += n; 1556 buf += n; 1557 len -= n; 1558 ret = n; 1559 if (r) { 1560 if (!n) 1561 ret = -EFAULT; 1562 goto out; 1563 } 1564 } 1565 1566 kvm = p->kvm; 1567 i = p->hpt_index; 1568 hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE)); 1569 for (; len != 0 && i < kvm->arch.hpt_npte; ++i, hptp += 2) { 1570 if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))) 1571 continue; 1572 1573 /* lock the HPTE so it's stable and read it */ 1574 preempt_disable(); 1575 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) 1576 cpu_relax(); 1577 v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK; 1578 hr = be64_to_cpu(hptp[1]); 1579 gr = kvm->arch.revmap[i].guest_rpte; 1580 unlock_hpte(hptp, v); 1581 preempt_enable(); 1582 1583 if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT))) 1584 continue; 1585 1586 n = scnprintf(p->buf, sizeof(p->buf), 1587 "%6lx %.16lx %.16lx %.16lx\n", 1588 i, v, hr, gr); 1589 p->chars_left = n; 1590 if (n > len) 1591 n = len; 1592 r = copy_to_user(buf, p->buf, n); 1593 n -= r; 1594 p->chars_left -= n; 1595 p->buf_index = n; 1596 buf += n; 1597 len -= n; 1598 ret += n; 1599 if (r) { 1600 if (!ret) 1601 ret = -EFAULT; 1602 goto out; 1603 } 1604 } 1605 p->hpt_index = i; 1606 1607 out: 1608 mutex_unlock(&p->mutex); 1609 return ret; 1610 } 1611 1612 ssize_t debugfs_htab_write(struct file *file, const char __user *buf, 1613 size_t len, loff_t *ppos) 1614 { 1615 return -EACCES; 1616 } 1617 1618 static const struct file_operations debugfs_htab_fops = { 1619 .owner = THIS_MODULE, 1620 .open = debugfs_htab_open, 1621 .release = debugfs_htab_release, 1622 .read = debugfs_htab_read, 1623 .write = debugfs_htab_write, 1624 .llseek = generic_file_llseek, 1625 }; 1626 1627 void kvmppc_mmu_debugfs_init(struct kvm *kvm) 1628 { 1629 kvm->arch.htab_dentry = debugfs_create_file("htab", 0400, 1630 kvm->arch.debugfs_dir, kvm, 1631 &debugfs_htab_fops); 1632 } 1633 1634 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) 1635 { 1636 struct kvmppc_mmu *mmu = &vcpu->arch.mmu; 1637 1638 vcpu->arch.slb_nr = 32; /* POWER7/POWER8 */ 1639 1640 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate; 1641 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr; 1642 1643 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; 1644 } 1645