arch/mips/kvm/tlb.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * KVM/MIPS TLB handling, this file is part of the Linux host kernel so that
   7  * TLB handlers run from KSEG0
   8  *
   9  * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
  10  * Authors: Sanjay Lal <sanjayl@kymasys.com>
  11  */
  12
  13 #include <linux/sched.h>
  14 #include <linux/smp.h>
  15 #include <linux/mm.h>
  16 #include <linux/delay.h>
  17 #include <linux/module.h>
  18 #include <linux/kvm_host.h>
  19 #include <linux/srcu.h>
  20
  21 #include <asm/cpu.h>
  22 #include <asm/bootinfo.h>
  23 #include <asm/mmu_context.h>
  24 #include <asm/pgtable.h>
  25 #include <asm/cacheflush.h>
  26 #include <asm/tlb.h>
  27
  28 #undef CONFIG_MIPS_MT
  29 #include <asm/r4kcache.h>
  30 #define CONFIG_MIPS_MT
  31
  32 #define KVM_GUEST_PC_TLB    0
  33 #define KVM_GUEST_SP_TLB    1
  34
  35 #define PRIx64 "llx"
  36
  37 atomic_t kvm_mips_instance;
  38 EXPORT_SYMBOL_GPL(kvm_mips_instance);
  39
  40 /* These function pointers are initialized once the KVM module is loaded */
  41 kvm_pfn_t (*kvm_mips_gfn_to_pfn)(struct kvm *kvm, gfn_t gfn);
  42 EXPORT_SYMBOL_GPL(kvm_mips_gfn_to_pfn);
  43
  44 void (*kvm_mips_release_pfn_clean)(kvm_pfn_t pfn);
  45 EXPORT_SYMBOL_GPL(kvm_mips_release_pfn_clean);
  46
  47 bool (*kvm_mips_is_error_pfn)(kvm_pfn_t pfn);
  48 EXPORT_SYMBOL_GPL(kvm_mips_is_error_pfn);
  49
  50 uint32_t kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
  51 {
  52         return vcpu->arch.guest_kernel_asid[smp_processor_id()] & ASID_MASK;
  53 }
  54
  55 uint32_t kvm_mips_get_user_asid(struct kvm_vcpu *vcpu)
  56 {
  57         return vcpu->arch.guest_user_asid[smp_processor_id()] & ASID_MASK;
  58 }
  59
  60 inline uint32_t kvm_mips_get_commpage_asid(struct kvm_vcpu *vcpu)
  61 {
  62         return vcpu->kvm->arch.commpage_tlb;
  63 }
  64
  65 /* Structure defining an tlb entry data set. */
  66
  67 void kvm_mips_dump_host_tlbs(void)
  68 {
  69         unsigned long old_entryhi;
  70         unsigned long old_pagemask;
  71         struct kvm_mips_tlb tlb;
  72         unsigned long flags;
  73         int i;
  74
  75         local_irq_save(flags);
  76
  77         old_entryhi = read_c0_entryhi();
  78         old_pagemask = read_c0_pagemask();
  79
  80         kvm_info("HOST TLBs:\n");
  81         kvm_info("ASID: %#lx\n", read_c0_entryhi() & ASID_MASK);
  82
  83         for (i = 0; i < current_cpu_data.tlbsize; i++) {
  84                 write_c0_index(i);
  85                 mtc0_tlbw_hazard();
  86
  87                 tlb_read();
  88                 tlbw_use_hazard();
  89
  90                 tlb.tlb_hi = read_c0_entryhi();
  91                 tlb.tlb_lo0 = read_c0_entrylo0();
  92                 tlb.tlb_lo1 = read_c0_entrylo1();
  93                 tlb.tlb_mask = read_c0_pagemask();
  94
  95                 kvm_info("TLB%c%3d Hi 0x%08lx ",
  96                          (tlb.tlb_lo0 | tlb.tlb_lo1) & MIPS3_PG_V ? ' ' : '*',
  97                          i, tlb.tlb_hi);
  98                 kvm_info("Lo0=0x%09" PRIx64 " %c%c attr %lx ",
  99                          (uint64_t) mips3_tlbpfn_to_paddr(tlb.tlb_lo0),
 100                          (tlb.tlb_lo0 & MIPS3_PG_D) ? 'D' : ' ',
 101                          (tlb.tlb_lo0 & MIPS3_PG_G) ? 'G' : ' ',
 102                          (tlb.tlb_lo0 >> 3) & 7);
 103                 kvm_info("Lo1=0x%09" PRIx64 " %c%c attr %lx sz=%lx\n",
 104                          (uint64_t) mips3_tlbpfn_to_paddr(tlb.tlb_lo1),
 105                          (tlb.tlb_lo1 & MIPS3_PG_D) ? 'D' : ' ',
 106                          (tlb.tlb_lo1 & MIPS3_PG_G) ? 'G' : ' ',
 107                          (tlb.tlb_lo1 >> 3) & 7, tlb.tlb_mask);
 108         }
 109         write_c0_entryhi(old_entryhi);
 110         write_c0_pagemask(old_pagemask);
 111         mtc0_tlbw_hazard();
 112         local_irq_restore(flags);
 113 }
 114 EXPORT_SYMBOL_GPL(kvm_mips_dump_host_tlbs);
 115
 116 void kvm_mips_dump_guest_tlbs(struct kvm_vcpu *vcpu)
 117 {
 118         struct mips_coproc *cop0 = vcpu->arch.cop0;
 119         struct kvm_mips_tlb tlb;
 120         int i;
 121
 122         kvm_info("Guest TLBs:\n");
 123         kvm_info("Guest EntryHi: %#lx\n", kvm_read_c0_guest_entryhi(cop0));
 124
 125         for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
 126                 tlb = vcpu->arch.guest_tlb[i];
 127                 kvm_info("TLB%c%3d Hi 0x%08lx ",
 128                          (tlb.tlb_lo0 | tlb.tlb_lo1) & MIPS3_PG_V ? ' ' : '*',
 129                          i, tlb.tlb_hi);
 130                 kvm_info("Lo0=0x%09" PRIx64 " %c%c attr %lx ",
 131                          (uint64_t) mips3_tlbpfn_to_paddr(tlb.tlb_lo0),
 132                          (tlb.tlb_lo0 & MIPS3_PG_D) ? 'D' : ' ',
 133                          (tlb.tlb_lo0 & MIPS3_PG_G) ? 'G' : ' ',
 134                          (tlb.tlb_lo0 >> 3) & 7);
 135                 kvm_info("Lo1=0x%09" PRIx64 " %c%c attr %lx sz=%lx\n",
 136                          (uint64_t) mips3_tlbpfn_to_paddr(tlb.tlb_lo1),
 137                          (tlb.tlb_lo1 & MIPS3_PG_D) ? 'D' : ' ',
 138                          (tlb.tlb_lo1 & MIPS3_PG_G) ? 'G' : ' ',
 139                          (tlb.tlb_lo1 >> 3) & 7, tlb.tlb_mask);
 140         }
 141 }
 142 EXPORT_SYMBOL_GPL(kvm_mips_dump_guest_tlbs);
 143
 144 static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
 145 {
 146         int srcu_idx, err = 0;
 147         kvm_pfn_t pfn;
 148
 149         if (kvm->arch.guest_pmap[gfn] != KVM_INVALID_PAGE)
 150                 return 0;
 151
 152         srcu_idx = srcu_read_lock(&kvm->srcu);
 153         pfn = kvm_mips_gfn_to_pfn(kvm, gfn);
 154
 155         if (kvm_mips_is_error_pfn(pfn)) {
 156                 kvm_err("Couldn't get pfn for gfn %#" PRIx64 "!\n", gfn);
 157                 err = -EFAULT;
 158                 goto out;
 159         }
 160
 161         kvm->arch.guest_pmap[gfn] = pfn;
 162 out:
 163         srcu_read_unlock(&kvm->srcu, srcu_idx);
 164         return err;
 165 }
 166
 167 /* Translate guest KSEG0 addresses to Host PA */
 168 unsigned long kvm_mips_translate_guest_kseg0_to_hpa(struct kvm_vcpu *vcpu,
 169                                                     unsigned long gva)
 170 {
 171         gfn_t gfn;
 172         uint32_t offset = gva & ~PAGE_MASK;
 173         struct kvm *kvm = vcpu->kvm;
 174
 175         if (KVM_GUEST_KSEGX(gva) != KVM_GUEST_KSEG0) {
 176                 kvm_err("%s/%p: Invalid gva: %#lx\n", __func__,
 177                         __builtin_return_address(0), gva);
 178                 return KVM_INVALID_PAGE;
 179         }
 180
 181         gfn = (KVM_GUEST_CPHYSADDR(gva) >> PAGE_SHIFT);
 182
 183         if (gfn >= kvm->arch.guest_pmap_npages) {
 184                 kvm_err("%s: Invalid gfn: %#llx, GVA: %#lx\n", __func__, gfn,
 185                         gva);
 186                 return KVM_INVALID_PAGE;
 187         }
 188
 189         if (kvm_mips_map_page(vcpu->kvm, gfn) < 0)
 190                 return KVM_INVALID_ADDR;
 191
 192         return (kvm->arch.guest_pmap[gfn] << PAGE_SHIFT) + offset;
 193 }
 194 EXPORT_SYMBOL_GPL(kvm_mips_translate_guest_kseg0_to_hpa);
 195
 196 /* XXXKYMA: Must be called with interrupts disabled */
 197 /* set flush_dcache_mask == 0 if no dcache flush required */
 198 int kvm_mips_host_tlb_write(struct kvm_vcpu *vcpu, unsigned long entryhi,
 199                             unsigned long entrylo0, unsigned long entrylo1,
 200                             int flush_dcache_mask)
 201 {
 202         unsigned long flags;
 203         unsigned long old_entryhi;
 204         int idx;
 205
 206         local_irq_save(flags);
 207
 208         old_entryhi = read_c0_entryhi();
 209         write_c0_entryhi(entryhi);
 210         mtc0_tlbw_hazard();
 211
 212         tlb_probe();
 213         tlb_probe_hazard();
 214         idx = read_c0_index();
 215
 216         if (idx > current_cpu_data.tlbsize) {
 217                 kvm_err("%s: Invalid Index: %d\n", __func__, idx);
 218                 kvm_mips_dump_host_tlbs();
 219                 local_irq_restore(flags);
 220                 return -1;
 221         }
 222
 223         write_c0_entrylo0(entrylo0);
 224         write_c0_entrylo1(entrylo1);
 225         mtc0_tlbw_hazard();
 226
 227         if (idx < 0)
 228                 tlb_write_random();
 229         else
 230                 tlb_write_indexed();
 231         tlbw_use_hazard();
 232
 233         kvm_debug("@ %#lx idx: %2d [entryhi(R): %#lx] entrylo0(R): 0x%08lx, entrylo1(R): 0x%08lx\n",
 234                   vcpu->arch.pc, idx, read_c0_entryhi(),
 235                   read_c0_entrylo0(), read_c0_entrylo1());
 236
 237         /* Flush D-cache */
 238         if (flush_dcache_mask) {
 239                 if (entrylo0 & MIPS3_PG_V) {
 240                         ++vcpu->stat.flush_dcache_exits;
 241                         flush_data_cache_page((entryhi & VPN2_MASK) &
 242                                               ~flush_dcache_mask);
 243                 }
 244                 if (entrylo1 & MIPS3_PG_V) {
 245                         ++vcpu->stat.flush_dcache_exits;
 246                         flush_data_cache_page(((entryhi & VPN2_MASK) &
 247                                                ~flush_dcache_mask) |
 248                                               (0x1 << PAGE_SHIFT));
 249                 }
 250         }
 251
 252         /* Restore old ASID */
 253         write_c0_entryhi(old_entryhi);
 254         mtc0_tlbw_hazard();
 255         tlbw_use_hazard();
 256         local_irq_restore(flags);
 257         return 0;
 258 }
 259
 260 /* XXXKYMA: Must be called with interrupts disabled */
 261 int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr,
 262                                     struct kvm_vcpu *vcpu)
 263 {
 264         gfn_t gfn;
 265         kvm_pfn_t pfn0, pfn1;
 266         unsigned long vaddr = 0;
 267         unsigned long entryhi = 0, entrylo0 = 0, entrylo1 = 0;
 268         int even;
 269         struct kvm *kvm = vcpu->kvm;
 270         const int flush_dcache_mask = 0;
 271         int ret;
 272
 273         if (KVM_GUEST_KSEGX(badvaddr) != KVM_GUEST_KSEG0) {
 274                 kvm_err("%s: Invalid BadVaddr: %#lx\n", __func__, badvaddr);
 275                 kvm_mips_dump_host_tlbs();
 276                 return -1;
 277         }
 278
 279         gfn = (KVM_GUEST_CPHYSADDR(badvaddr) >> PAGE_SHIFT);
 280         if (gfn >= kvm->arch.guest_pmap_npages) {
 281                 kvm_err("%s: Invalid gfn: %#llx, BadVaddr: %#lx\n", __func__,
 282                         gfn, badvaddr);
 283                 kvm_mips_dump_host_tlbs();
 284                 return -1;
 285         }
 286         even = !(gfn & 0x1);
 287         vaddr = badvaddr & (PAGE_MASK << 1);
 288
 289         if (kvm_mips_map_page(vcpu->kvm, gfn) < 0)
 290                 return -1;
 291
 292         if (kvm_mips_map_page(vcpu->kvm, gfn ^ 0x1) < 0)
 293                 return -1;
 294
 295         if (even) {
 296                 pfn0 = kvm->arch.guest_pmap[gfn];
 297                 pfn1 = kvm->arch.guest_pmap[gfn ^ 0x1];
 298         } else {
 299                 pfn0 = kvm->arch.guest_pmap[gfn ^ 0x1];
 300                 pfn1 = kvm->arch.guest_pmap[gfn];
 301         }
 302
 303         entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) | (0x3 << 3) |
 304                    (1 << 2) | (0x1 << 1);
 305         entrylo1 = mips3_paddr_to_tlbpfn(pfn1 << PAGE_SHIFT) | (0x3 << 3) |
 306                    (1 << 2) | (0x1 << 1);
 307
 308         preempt_disable();
 309         entryhi = (vaddr | kvm_mips_get_kernel_asid(vcpu));
 310         ret = kvm_mips_host_tlb_write(vcpu, entryhi, entrylo0, entrylo1,
 311                                       flush_dcache_mask);
 312         preempt_enable();
 313
 314         return ret;
 315 }
 316 EXPORT_SYMBOL_GPL(kvm_mips_handle_kseg0_tlb_fault);
 317
 318 int kvm_mips_handle_commpage_tlb_fault(unsigned long badvaddr,
 319         struct kvm_vcpu *vcpu)
 320 {
 321         kvm_pfn_t pfn0, pfn1;
 322         unsigned long flags, old_entryhi = 0, vaddr = 0;
 323         unsigned long entrylo0 = 0, entrylo1 = 0;
 324
 325         pfn0 = CPHYSADDR(vcpu->arch.kseg0_commpage) >> PAGE_SHIFT;
 326         pfn1 = 0;
 327         entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) | (0x3 << 3) |
 328                    (1 << 2) | (0x1 << 1);
 329         entrylo1 = 0;
 330
 331         local_irq_save(flags);
 332
 333         old_entryhi = read_c0_entryhi();
 334         vaddr = badvaddr & (PAGE_MASK << 1);
 335         write_c0_entryhi(vaddr | kvm_mips_get_kernel_asid(vcpu));
 336         mtc0_tlbw_hazard();
 337         write_c0_entrylo0(entrylo0);
 338         mtc0_tlbw_hazard();
 339         write_c0_entrylo1(entrylo1);
 340         mtc0_tlbw_hazard();
 341         write_c0_index(kvm_mips_get_commpage_asid(vcpu));
 342         mtc0_tlbw_hazard();
 343         tlb_write_indexed();
 344         mtc0_tlbw_hazard();
 345         tlbw_use_hazard();
 346
 347         kvm_debug("@ %#lx idx: %2d [entryhi(R): %#lx] entrylo0 (R): 0x%08lx, entrylo1(R): 0x%08lx\n",
 348                   vcpu->arch.pc, read_c0_index(), read_c0_entryhi(),
 349                   read_c0_entrylo0(), read_c0_entrylo1());
 350
 351         /* Restore old ASID */
 352         write_c0_entryhi(old_entryhi);
 353         mtc0_tlbw_hazard();
 354         tlbw_use_hazard();
 355         local_irq_restore(flags);
 356
 357         return 0;
 358 }
 359 EXPORT_SYMBOL_GPL(kvm_mips_handle_commpage_tlb_fault);
 360
 361 int kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu *vcpu,
 362                                          struct kvm_mips_tlb *tlb,
 363                                          unsigned long *hpa0,
 364                                          unsigned long *hpa1)
 365 {
 366         unsigned long entryhi = 0, entrylo0 = 0, entrylo1 = 0;
 367         struct kvm *kvm = vcpu->kvm;
 368         kvm_pfn_t pfn0, pfn1;
 369         int ret;
 370
 371         if ((tlb->tlb_hi & VPN2_MASK) == 0) {
 372                 pfn0 = 0;
 373                 pfn1 = 0;
 374         } else {
 375                 if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo0)
 376                                            >> PAGE_SHIFT) < 0)
 377                         return -1;
 378
 379                 if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo1)
 380                                            >> PAGE_SHIFT) < 0)
 381                         return -1;
 382
 383                 pfn0 = kvm->arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb->tlb_lo0)
 384                                             >> PAGE_SHIFT];
 385                 pfn1 = kvm->arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb->tlb_lo1)
 386                                             >> PAGE_SHIFT];
 387         }
 388
 389         if (hpa0)
 390                 *hpa0 = pfn0 << PAGE_SHIFT;
 391
 392         if (hpa1)
 393                 *hpa1 = pfn1 << PAGE_SHIFT;
 394
 395         /* Get attributes from the Guest TLB */
 396         entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) | (0x3 << 3) |
 397                    (tlb->tlb_lo0 & MIPS3_PG_D) | (tlb->tlb_lo0 & MIPS3_PG_V);
 398         entrylo1 = mips3_paddr_to_tlbpfn(pfn1 << PAGE_SHIFT) | (0x3 << 3) |
 399                    (tlb->tlb_lo1 & MIPS3_PG_D) | (tlb->tlb_lo1 & MIPS3_PG_V);
 400
 401         kvm_debug("@ %#lx tlb_lo0: 0x%08lx tlb_lo1: 0x%08lx\n", vcpu->arch.pc,
 402                   tlb->tlb_lo0, tlb->tlb_lo1);
 403
 404         preempt_disable();
 405         entryhi = (tlb->tlb_hi & VPN2_MASK) | (KVM_GUEST_KERNEL_MODE(vcpu) ?
 406                                                kvm_mips_get_kernel_asid(vcpu) :
 407                                                kvm_mips_get_user_asid(vcpu));
 408         ret = kvm_mips_host_tlb_write(vcpu, entryhi, entrylo0, entrylo1,
 409                                       tlb->tlb_mask);
 410         preempt_enable();
 411
 412         return ret;
 413 }
 414 EXPORT_SYMBOL_GPL(kvm_mips_handle_mapped_seg_tlb_fault);
 415
 416 int kvm_mips_guest_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long entryhi)
 417 {
 418         int i;
 419         int index = -1;
 420         struct kvm_mips_tlb *tlb = vcpu->arch.guest_tlb;
 421
 422         for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
 423                 if (TLB_HI_VPN2_HIT(tlb[i], entryhi) &&
 424                     TLB_HI_ASID_HIT(tlb[i], entryhi)) {
 425                         index = i;
 426                         break;
 427                 }
 428         }
 429
 430         kvm_debug("%s: entryhi: %#lx, index: %d lo0: %#lx, lo1: %#lx\n",
 431                   __func__, entryhi, index, tlb[i].tlb_lo0, tlb[i].tlb_lo1);
 432
 433         return index;
 434 }
 435 EXPORT_SYMBOL_GPL(kvm_mips_guest_tlb_lookup);
 436
 437 int kvm_mips_host_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long vaddr)
 438 {
 439         unsigned long old_entryhi, flags;
 440         int idx;
 441
 442         local_irq_save(flags);
 443
 444         old_entryhi = read_c0_entryhi();
 445
 446         if (KVM_GUEST_KERNEL_MODE(vcpu))
 447                 write_c0_entryhi((vaddr & VPN2_MASK) |
 448                                  kvm_mips_get_kernel_asid(vcpu));
 449         else {
 450                 write_c0_entryhi((vaddr & VPN2_MASK) |
 451                                  kvm_mips_get_user_asid(vcpu));
 452         }
 453
 454         mtc0_tlbw_hazard();
 455
 456         tlb_probe();
 457         tlb_probe_hazard();
 458         idx = read_c0_index();
 459
 460         /* Restore old ASID */
 461         write_c0_entryhi(old_entryhi);
 462         mtc0_tlbw_hazard();
 463         tlbw_use_hazard();
 464
 465         local_irq_restore(flags);
 466
 467         kvm_debug("Host TLB lookup, %#lx, idx: %2d\n", vaddr, idx);
 468
 469         return idx;
 470 }
 471 EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_lookup);
 472
 473 int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va)
 474 {
 475         int idx;
 476         unsigned long flags, old_entryhi;
 477
 478         local_irq_save(flags);
 479
 480         old_entryhi = read_c0_entryhi();
 481
 482         write_c0_entryhi((va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu));
 483         mtc0_tlbw_hazard();
 484
 485         tlb_probe();
 486         tlb_probe_hazard();
 487         idx = read_c0_index();
 488
 489         if (idx >= current_cpu_data.tlbsize)
 490                 BUG();
 491
 492         if (idx > 0) {
 493                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 494                 mtc0_tlbw_hazard();
 495
 496                 write_c0_entrylo0(0);
 497                 mtc0_tlbw_hazard();
 498
 499                 write_c0_entrylo1(0);
 500                 mtc0_tlbw_hazard();
 501
 502                 tlb_write_indexed();
 503                 mtc0_tlbw_hazard();
 504         }
 505
 506         write_c0_entryhi(old_entryhi);
 507         mtc0_tlbw_hazard();
 508         tlbw_use_hazard();
 509
 510         local_irq_restore(flags);
 511
 512         if (idx > 0)
 513                 kvm_debug("%s: Invalidated entryhi %#lx @ idx %d\n", __func__,
 514                           (va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu), idx);
 515
 516         return 0;
 517 }
 518 EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_inv);
 519
 520 void kvm_mips_flush_host_tlb(int skip_kseg0)
 521 {
 522         unsigned long flags;
 523         unsigned long old_entryhi, entryhi;
 524         unsigned long old_pagemask;
 525         int entry = 0;
 526         int maxentry = current_cpu_data.tlbsize;
 527
 528         local_irq_save(flags);
 529
 530         old_entryhi = read_c0_entryhi();
 531         old_pagemask = read_c0_pagemask();
 532
 533         /* Blast 'em all away. */
 534         for (entry = 0; entry < maxentry; entry++) {
 535                 write_c0_index(entry);
 536                 mtc0_tlbw_hazard();
 537
 538                 if (skip_kseg0) {
 539                         tlb_read();
 540                         tlbw_use_hazard();
 541
 542                         entryhi = read_c0_entryhi();
 543
 544                         /* Don't blow away guest kernel entries */
 545                         if (KVM_GUEST_KSEGX(entryhi) == KVM_GUEST_KSEG0)
 546                                 continue;
 547                 }
 548
 549                 /* Make sure all entries differ. */
 550                 write_c0_entryhi(UNIQUE_ENTRYHI(entry));
 551                 mtc0_tlbw_hazard();
 552                 write_c0_entrylo0(0);
 553                 mtc0_tlbw_hazard();
 554                 write_c0_entrylo1(0);
 555                 mtc0_tlbw_hazard();
 556
 557                 tlb_write_indexed();
 558                 mtc0_tlbw_hazard();
 559         }
 560
 561         tlbw_use_hazard();
 562
 563         write_c0_entryhi(old_entryhi);
 564         write_c0_pagemask(old_pagemask);
 565         mtc0_tlbw_hazard();
 566         tlbw_use_hazard();
 567
 568         local_irq_restore(flags);
 569 }
 570 EXPORT_SYMBOL_GPL(kvm_mips_flush_host_tlb);
 571
 572 void kvm_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu,
 573                              struct kvm_vcpu *vcpu)
 574 {
 575         unsigned long asid = asid_cache(cpu);
 576
 577         asid += ASID_INC;
 578         if (!(asid & ASID_MASK)) {
 579                 if (cpu_has_vtag_icache)
 580                         flush_icache_all();
 581
 582                 kvm_local_flush_tlb_all();      /* start new asid cycle */
 583
 584                 if (!asid)      /* fix version if needed */
 585                         asid = ASID_FIRST_VERSION;
 586         }
 587
 588         cpu_context(cpu, mm) = asid_cache(cpu) = asid;
 589 }
 590
 591 void kvm_local_flush_tlb_all(void)
 592 {
 593         unsigned long flags;
 594         unsigned long old_ctx;
 595         int entry = 0;
 596
 597         local_irq_save(flags);
 598         /* Save old context and create impossible VPN2 value */
 599         old_ctx = read_c0_entryhi();
 600         write_c0_entrylo0(0);
 601         write_c0_entrylo1(0);
 602
 603         /* Blast 'em all away. */
 604         while (entry < current_cpu_data.tlbsize) {
 605                 /* Make sure all entries differ. */
 606                 write_c0_entryhi(UNIQUE_ENTRYHI(entry));
 607                 write_c0_index(entry);
 608                 mtc0_tlbw_hazard();
 609                 tlb_write_indexed();
 610                 entry++;
 611         }
 612         tlbw_use_hazard();
 613         write_c0_entryhi(old_ctx);
 614         mtc0_tlbw_hazard();
 615
 616         local_irq_restore(flags);
 617 }
 618 EXPORT_SYMBOL_GPL(kvm_local_flush_tlb_all);
 619
 620 /**
 621  * kvm_mips_migrate_count() - Migrate timer.
 622  * @vcpu:       Virtual CPU.
 623  *
 624  * Migrate CP0_Count hrtimer to the current CPU by cancelling and restarting it
 625  * if it was running prior to being cancelled.
 626  *
 627  * Must be called when the VCPU is migrated to a different CPU to ensure that
 628  * timer expiry during guest execution interrupts the guest and causes the
 629  * interrupt to be delivered in a timely manner.
 630  */
 631 static void kvm_mips_migrate_count(struct kvm_vcpu *vcpu)
 632 {
 633         if (hrtimer_cancel(&vcpu->arch.comparecount_timer))
 634                 hrtimer_restart(&vcpu->arch.comparecount_timer);
 635 }
 636
 637 /* Restore ASID once we are scheduled back after preemption */
 638 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 639 {
 640         unsigned long flags;
 641         int newasid = 0;
 642
 643         kvm_debug("%s: vcpu %p, cpu: %d\n", __func__, vcpu, cpu);
 644
 645         /* Allocate new kernel and user ASIDs if needed */
 646
 647         local_irq_save(flags);
 648
 649         if ((vcpu->arch.guest_kernel_asid[cpu] ^ asid_cache(cpu)) &
 650                                                         ASID_VERSION_MASK) {
 651                 kvm_get_new_mmu_context(&vcpu->arch.guest_kernel_mm, cpu, vcpu);
 652                 vcpu->arch.guest_kernel_asid[cpu] =
 653                     vcpu->arch.guest_kernel_mm.context.asid[cpu];
 654                 kvm_get_new_mmu_context(&vcpu->arch.guest_user_mm, cpu, vcpu);
 655                 vcpu->arch.guest_user_asid[cpu] =
 656                     vcpu->arch.guest_user_mm.context.asid[cpu];
 657                 newasid++;
 658
 659                 kvm_debug("[%d]: cpu_context: %#lx\n", cpu,
 660                           cpu_context(cpu, current->mm));
 661                 kvm_debug("[%d]: Allocated new ASID for Guest Kernel: %#x\n",
 662                           cpu, vcpu->arch.guest_kernel_asid[cpu]);
 663                 kvm_debug("[%d]: Allocated new ASID for Guest User: %#x\n", cpu,
 664                           vcpu->arch.guest_user_asid[cpu]);
 665         }
 666
 667         if (vcpu->arch.last_sched_cpu != cpu) {
 668                 kvm_debug("[%d->%d]KVM VCPU[%d] switch\n",
 669                           vcpu->arch.last_sched_cpu, cpu, vcpu->vcpu_id);
 670                 /*
 671                  * Migrate the timer interrupt to the current CPU so that it
 672                  * always interrupts the guest and synchronously triggers a
 673                  * guest timer interrupt.
 674                  */
 675                 kvm_mips_migrate_count(vcpu);
 676         }
 677
 678         if (!newasid) {
 679                 /*
 680                  * If we preempted while the guest was executing, then reload
 681                  * the pre-empted ASID
 682                  */
 683                 if (current->flags & PF_VCPU) {
 684                         write_c0_entryhi(vcpu->arch.
 685                                          preempt_entryhi & ASID_MASK);
 686                         ehb();
 687                 }
 688         } else {
 689                 /* New ASIDs were allocated for the VM */
 690
 691                 /*
 692                  * Were we in guest context? If so then the pre-empted ASID is
 693                  * no longer valid, we need to set it to what it should be based
 694                  * on the mode of the Guest (Kernel/User)
 695                  */
 696                 if (current->flags & PF_VCPU) {
 697                         if (KVM_GUEST_KERNEL_MODE(vcpu))
 698                                 write_c0_entryhi(vcpu->arch.
 699                                                  guest_kernel_asid[cpu] &
 700                                                  ASID_MASK);
 701                         else
 702                                 write_c0_entryhi(vcpu->arch.
 703                                                  guest_user_asid[cpu] &
 704                                                  ASID_MASK);
 705                         ehb();
 706                 }
 707         }
 708
 709         /* restore guest state to registers */
 710         kvm_mips_callbacks->vcpu_set_regs(vcpu);
 711
 712         local_irq_restore(flags);
 713
 714 }
 715 EXPORT_SYMBOL_GPL(kvm_arch_vcpu_load);
 716
 717 /* ASID can change if another task is scheduled during preemption */
 718 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 719 {
 720         unsigned long flags;
 721         uint32_t cpu;
 722
 723         local_irq_save(flags);
 724
 725         cpu = smp_processor_id();
 726
 727         vcpu->arch.preempt_entryhi = read_c0_entryhi();
 728         vcpu->arch.last_sched_cpu = cpu;
 729
 730         /* save guest state in registers */
 731         kvm_mips_callbacks->vcpu_get_regs(vcpu);
 732
 733         if (((cpu_context(cpu, current->mm) ^ asid_cache(cpu)) &
 734              ASID_VERSION_MASK)) {
 735                 kvm_debug("%s: Dropping MMU Context:  %#lx\n", __func__,
 736                           cpu_context(cpu, current->mm));
 737                 drop_mmu_context(current->mm, cpu);
 738         }
 739         write_c0_entryhi(cpu_asid(cpu, current->mm));
 740         ehb();
 741
 742         local_irq_restore(flags);
 743 }
 744 EXPORT_SYMBOL_GPL(kvm_arch_vcpu_put);
 745
 746 uint32_t kvm_get_inst(uint32_t *opc, struct kvm_vcpu *vcpu)
 747 {
 748         struct mips_coproc *cop0 = vcpu->arch.cop0;
 749         unsigned long paddr, flags, vpn2, asid;
 750         uint32_t inst;
 751         int index;
 752
 753         if (KVM_GUEST_KSEGX((unsigned long) opc) < KVM_GUEST_KSEG0 ||
 754             KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
 755                 local_irq_save(flags);
 756                 index = kvm_mips_host_tlb_lookup(vcpu, (unsigned long) opc);
 757                 if (index >= 0) {
 758                         inst = *(opc);
 759                 } else {
 760                         vpn2 = (unsigned long) opc & VPN2_MASK;
 761                         asid = kvm_read_c0_guest_entryhi(cop0) & ASID_MASK;
 762                         index = kvm_mips_guest_tlb_lookup(vcpu, vpn2 | asid);
 763                         if (index < 0) {
 764                                 kvm_err("%s: get_user_failed for %p, vcpu: %p, ASID: %#lx\n",
 765                                         __func__, opc, vcpu, read_c0_entryhi());
 766                                 kvm_mips_dump_host_tlbs();
 767                                 local_irq_restore(flags);
 768                                 return KVM_INVALID_INST;
 769                         }
 770                         kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
 771                                                              &vcpu->arch.
 772                                                              guest_tlb[index],
 773                                                              NULL, NULL);
 774                         inst = *(opc);
 775                 }
 776                 local_irq_restore(flags);
 777         } else if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
 778                 paddr =
 779                     kvm_mips_translate_guest_kseg0_to_hpa(vcpu,
 780                                                           (unsigned long) opc);
 781                 inst = *(uint32_t *) CKSEG0ADDR(paddr);
 782         } else {
 783                 kvm_err("%s: illegal address: %p\n", __func__, opc);
 784                 return KVM_INVALID_INST;
 785         }
 786
 787         return inst;
 788 }
 789 EXPORT_SYMBOL_GPL(kvm_get_inst);