arch/mips/kvm/mips.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: MIPS specific KVM APIs
   7  *
   8  * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
   9  * Authors: Sanjay Lal <sanjayl@kymasys.com>
  10  */
  11
  12 #include <linux/errno.h>
  13 #include <linux/err.h>
  14 #include <linux/kdebug.h>
  15 #include <linux/module.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/fs.h>
  18 #include <linux/bootmem.h>
  19 #include <asm/fpu.h>
  20 #include <asm/page.h>
  21 #include <asm/cacheflush.h>
  22 #include <asm/mmu_context.h>
  23 #include <asm/pgtable.h>
  24
  25 #include <linux/kvm_host.h>
  26
  27 #include "interrupt.h"
  28 #include "commpage.h"
  29
  30 #define CREATE_TRACE_POINTS
  31 #include "trace.h"
  32
  33 #ifndef VECTORSPACING
  34 #define VECTORSPACING 0x100     /* for EI/VI mode */
  35 #endif
  36
  37 #define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x)
  38 struct kvm_stats_debugfs_item debugfs_entries[] = {
  39         { "wait",         VCPU_STAT(wait_exits),         KVM_STAT_VCPU },
  40         { "cache",        VCPU_STAT(cache_exits),        KVM_STAT_VCPU },
  41         { "signal",       VCPU_STAT(signal_exits),       KVM_STAT_VCPU },
  42         { "interrupt",    VCPU_STAT(int_exits),          KVM_STAT_VCPU },
  43         { "cop_unsuable", VCPU_STAT(cop_unusable_exits), KVM_STAT_VCPU },
  44         { "tlbmod",       VCPU_STAT(tlbmod_exits),       KVM_STAT_VCPU },
  45         { "tlbmiss_ld",   VCPU_STAT(tlbmiss_ld_exits),   KVM_STAT_VCPU },
  46         { "tlbmiss_st",   VCPU_STAT(tlbmiss_st_exits),   KVM_STAT_VCPU },
  47         { "addrerr_st",   VCPU_STAT(addrerr_st_exits),   KVM_STAT_VCPU },
  48         { "addrerr_ld",   VCPU_STAT(addrerr_ld_exits),   KVM_STAT_VCPU },
  49         { "syscall",      VCPU_STAT(syscall_exits),      KVM_STAT_VCPU },
  50         { "resvd_inst",   VCPU_STAT(resvd_inst_exits),   KVM_STAT_VCPU },
  51         { "break_inst",   VCPU_STAT(break_inst_exits),   KVM_STAT_VCPU },
  52         { "trap_inst",    VCPU_STAT(trap_inst_exits),    KVM_STAT_VCPU },
  53         { "fpe",          VCPU_STAT(fpe_exits),          KVM_STAT_VCPU },
  54         { "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU },
  55         { "halt_successful_poll", VCPU_STAT(halt_successful_poll), KVM_STAT_VCPU },
  56         { "halt_wakeup",  VCPU_STAT(halt_wakeup),        KVM_STAT_VCPU },
  57         {NULL}
  58 };
  59
  60 static int kvm_mips_reset_vcpu(struct kvm_vcpu *vcpu)
  61 {
  62         int i;
  63
  64         for_each_possible_cpu(i) {
  65                 vcpu->arch.guest_kernel_asid[i] = 0;
  66                 vcpu->arch.guest_user_asid[i] = 0;
  67         }
  68
  69         return 0;
  70 }
  71
  72 /*
  73  * XXXKYMA: We are simulatoring a processor that has the WII bit set in
  74  * Config7, so we are "runnable" if interrupts are pending
  75  */
  76 int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
  77 {
  78         return !!(vcpu->arch.pending_exceptions);
  79 }
  80
  81 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
  82 {
  83         return 1;
  84 }
  85
  86 int kvm_arch_hardware_enable(void)
  87 {
  88         return 0;
  89 }
  90
  91 int kvm_arch_hardware_setup(void)
  92 {
  93         return 0;
  94 }
  95
  96 void kvm_arch_check_processor_compat(void *rtn)
  97 {
  98         *(int *)rtn = 0;
  99 }
 100
 101 static void kvm_mips_init_tlbs(struct kvm *kvm)
 102 {
 103         unsigned long wired;
 104
 105         /*
 106          * Add a wired entry to the TLB, it is used to map the commpage to
 107          * the Guest kernel
 108          */
 109         wired = read_c0_wired();
 110         write_c0_wired(wired + 1);
 111         mtc0_tlbw_hazard();
 112         kvm->arch.commpage_tlb = wired;
 113
 114         kvm_debug("[%d] commpage TLB: %d\n", smp_processor_id(),
 115                   kvm->arch.commpage_tlb);
 116 }
 117
 118 static void kvm_mips_init_vm_percpu(void *arg)
 119 {
 120         struct kvm *kvm = (struct kvm *)arg;
 121
 122         kvm_mips_init_tlbs(kvm);
 123         kvm_mips_callbacks->vm_init(kvm);
 124
 125 }
 126
 127 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 128 {
 129         if (atomic_inc_return(&kvm_mips_instance) == 1) {
 130                 kvm_debug("%s: 1st KVM instance, setup host TLB parameters\n",
 131                           __func__);
 132                 on_each_cpu(kvm_mips_init_vm_percpu, kvm, 1);
 133         }
 134
 135         return 0;
 136 }
 137
 138 void kvm_mips_free_vcpus(struct kvm *kvm)
 139 {
 140         unsigned int i;
 141         struct kvm_vcpu *vcpu;
 142
 143         /* Put the pages we reserved for the guest pmap */
 144         for (i = 0; i < kvm->arch.guest_pmap_npages; i++) {
 145                 if (kvm->arch.guest_pmap[i] != KVM_INVALID_PAGE)
 146                         kvm_mips_release_pfn_clean(kvm->arch.guest_pmap[i]);
 147         }
 148         kfree(kvm->arch.guest_pmap);
 149
 150         kvm_for_each_vcpu(i, vcpu, kvm) {
 151                 kvm_arch_vcpu_free(vcpu);
 152         }
 153
 154         mutex_lock(&kvm->lock);
 155
 156         for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
 157                 kvm->vcpus[i] = NULL;
 158
 159         atomic_set(&kvm->online_vcpus, 0);
 160
 161         mutex_unlock(&kvm->lock);
 162 }
 163
 164 static void kvm_mips_uninit_tlbs(void *arg)
 165 {
 166         /* Restore wired count */
 167         write_c0_wired(0);
 168         mtc0_tlbw_hazard();
 169         /* Clear out all the TLBs */
 170         kvm_local_flush_tlb_all();
 171 }
 172
 173 void kvm_arch_destroy_vm(struct kvm *kvm)
 174 {
 175         kvm_mips_free_vcpus(kvm);
 176
 177         /* If this is the last instance, restore wired count */
 178         if (atomic_dec_return(&kvm_mips_instance) == 0) {
 179                 kvm_debug("%s: last KVM instance, restoring TLB parameters\n",
 180                           __func__);
 181                 on_each_cpu(kvm_mips_uninit_tlbs, NULL, 1);
 182         }
 183 }
 184
 185 long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl,
 186                         unsigned long arg)
 187 {
 188         return -ENOIOCTLCMD;
 189 }
 190
 191 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
 192                             unsigned long npages)
 193 {
 194         return 0;
 195 }
 196
 197 int kvm_arch_prepare_memory_region(struct kvm *kvm,
 198                                    struct kvm_memory_slot *memslot,
 199                                    struct kvm_userspace_memory_region *mem,
 200                                    enum kvm_mr_change change)
 201 {
 202         return 0;
 203 }
 204
 205 void kvm_arch_commit_memory_region(struct kvm *kvm,
 206                                    struct kvm_userspace_memory_region *mem,
 207                                    const struct kvm_memory_slot *old,
 208                                    enum kvm_mr_change change)
 209 {
 210         unsigned long npages = 0;
 211         int i;
 212
 213         kvm_debug("%s: kvm: %p slot: %d, GPA: %llx, size: %llx, QVA: %llx\n",
 214                   __func__, kvm, mem->slot, mem->guest_phys_addr,
 215                   mem->memory_size, mem->userspace_addr);
 216
 217         /* Setup Guest PMAP table */
 218         if (!kvm->arch.guest_pmap) {
 219                 if (mem->slot == 0)
 220                         npages = mem->memory_size >> PAGE_SHIFT;
 221
 222                 if (npages) {
 223                         kvm->arch.guest_pmap_npages = npages;
 224                         kvm->arch.guest_pmap =
 225                             kzalloc(npages * sizeof(unsigned long), GFP_KERNEL);
 226
 227                         if (!kvm->arch.guest_pmap) {
 228                                 kvm_err("Failed to allocate guest PMAP");
 229                                 return;
 230                         }
 231
 232                         kvm_debug("Allocated space for Guest PMAP Table (%ld pages) @ %p\n",
 233                                   npages, kvm->arch.guest_pmap);
 234
 235                         /* Now setup the page table */
 236                         for (i = 0; i < npages; i++)
 237                                 kvm->arch.guest_pmap[i] = KVM_INVALID_PAGE;
 238                 }
 239         }
 240 }
 241
 242 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 243 {
 244         int err, size, offset;
 245         void *gebase;
 246         int i;
 247
 248         struct kvm_vcpu *vcpu = kzalloc(sizeof(struct kvm_vcpu), GFP_KERNEL);
 249
 250         if (!vcpu) {
 251                 err = -ENOMEM;
 252                 goto out;
 253         }
 254
 255         err = kvm_vcpu_init(vcpu, kvm, id);
 256
 257         if (err)
 258                 goto out_free_cpu;
 259
 260         kvm_debug("kvm @ %p: create cpu %d at %p\n", kvm, id, vcpu);
 261
 262         /*
 263          * Allocate space for host mode exception handlers that handle
 264          * guest mode exits
 265          */
 266         if (cpu_has_veic || cpu_has_vint)
 267                 size = 0x200 + VECTORSPACING * 64;
 268         else
 269                 size = 0x4000;
 270
 271         /* Save Linux EBASE */
 272         vcpu->arch.host_ebase = (void *)read_c0_ebase();
 273
 274         gebase = kzalloc(ALIGN(size, PAGE_SIZE), GFP_KERNEL);
 275
 276         if (!gebase) {
 277                 err = -ENOMEM;
 278                 goto out_free_cpu;
 279         }
 280         kvm_debug("Allocated %d bytes for KVM Exception Handlers @ %p\n",
 281                   ALIGN(size, PAGE_SIZE), gebase);
 282
 283         /* Save new ebase */
 284         vcpu->arch.guest_ebase = gebase;
 285
 286         /* Copy L1 Guest Exception handler to correct offset */
 287
 288         /* TLB Refill, EXL = 0 */
 289         memcpy(gebase, mips32_exception,
 290                mips32_exceptionEnd - mips32_exception);
 291
 292         /* General Exception Entry point */
 293         memcpy(gebase + 0x180, mips32_exception,
 294                mips32_exceptionEnd - mips32_exception);
 295
 296         /* For vectored interrupts poke the exception code @ all offsets 0-7 */
 297         for (i = 0; i < 8; i++) {
 298                 kvm_debug("L1 Vectored handler @ %p\n",
 299                           gebase + 0x200 + (i * VECTORSPACING));
 300                 memcpy(gebase + 0x200 + (i * VECTORSPACING), mips32_exception,
 301                        mips32_exceptionEnd - mips32_exception);
 302         }
 303
 304         /* General handler, relocate to unmapped space for sanity's sake */
 305         offset = 0x2000;
 306         kvm_debug("Installing KVM Exception handlers @ %p, %#x bytes\n",
 307                   gebase + offset,
 308                   mips32_GuestExceptionEnd - mips32_GuestException);
 309
 310         memcpy(gebase + offset, mips32_GuestException,
 311                mips32_GuestExceptionEnd - mips32_GuestException);
 312
 313         /* Invalidate the icache for these ranges */
 314         local_flush_icache_range((unsigned long)gebase,
 315                                 (unsigned long)gebase + ALIGN(size, PAGE_SIZE));
 316
 317         /*
 318          * Allocate comm page for guest kernel, a TLB will be reserved for
 319          * mapping GVA @ 0xFFFF8000 to this page
 320          */
 321         vcpu->arch.kseg0_commpage = kzalloc(PAGE_SIZE << 1, GFP_KERNEL);
 322
 323         if (!vcpu->arch.kseg0_commpage) {
 324                 err = -ENOMEM;
 325                 goto out_free_gebase;
 326         }
 327
 328         kvm_debug("Allocated COMM page @ %p\n", vcpu->arch.kseg0_commpage);
 329         kvm_mips_commpage_init(vcpu);
 330
 331         /* Init */
 332         vcpu->arch.last_sched_cpu = -1;
 333
 334         /* Start off the timer */
 335         kvm_mips_init_count(vcpu);
 336
 337         return vcpu;
 338
 339 out_free_gebase:
 340         kfree(gebase);
 341
 342 out_free_cpu:
 343         kfree(vcpu);
 344
 345 out:
 346         return ERR_PTR(err);
 347 }
 348
 349 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
 350 {
 351         hrtimer_cancel(&vcpu->arch.comparecount_timer);
 352
 353         kvm_vcpu_uninit(vcpu);
 354
 355         kvm_mips_dump_stats(vcpu);
 356
 357         kfree(vcpu->arch.guest_ebase);
 358         kfree(vcpu->arch.kseg0_commpage);
 359         kfree(vcpu);
 360 }
 361
 362 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
 363 {
 364         kvm_arch_vcpu_free(vcpu);
 365 }
 366
 367 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 368                                         struct kvm_guest_debug *dbg)
 369 {
 370         return -ENOIOCTLCMD;
 371 }
 372
 373 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 374 {
 375         int r = 0;
 376         sigset_t sigsaved;
 377
 378         if (vcpu->sigset_active)
 379                 sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
 380
 381         if (vcpu->mmio_needed) {
 382                 if (!vcpu->mmio_is_write)
 383                         kvm_mips_complete_mmio_load(vcpu, run);
 384                 vcpu->mmio_needed = 0;
 385         }
 386
 387         lose_fpu(1);
 388
 389         local_irq_disable();
 390         /* Check if we have any exceptions/interrupts pending */
 391         kvm_mips_deliver_interrupts(vcpu,
 392                                     kvm_read_c0_guest_cause(vcpu->arch.cop0));
 393
 394         kvm_guest_enter();
 395
 396         /* Disable hardware page table walking while in guest */
 397         htw_stop();
 398
 399         r = __kvm_mips_vcpu_run(run, vcpu);
 400
 401         /* Re-enable HTW before enabling interrupts */
 402         htw_start();
 403
 404         kvm_guest_exit();
 405         local_irq_enable();
 406
 407         if (vcpu->sigset_active)
 408                 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 409
 410         return r;
 411 }
 412
 413 int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
 414                              struct kvm_mips_interrupt *irq)
 415 {
 416         int intr = (int)irq->irq;
 417         struct kvm_vcpu *dvcpu = NULL;
 418
 419         if (intr == 3 || intr == -3 || intr == 4 || intr == -4)
 420                 kvm_debug("%s: CPU: %d, INTR: %d\n", __func__, irq->cpu,
 421                           (int)intr);
 422
 423         if (irq->cpu == -1)
 424                 dvcpu = vcpu;
 425         else
 426                 dvcpu = vcpu->kvm->vcpus[irq->cpu];
 427
 428         if (intr == 2 || intr == 3 || intr == 4) {
 429                 kvm_mips_callbacks->queue_io_int(dvcpu, irq);
 430
 431         } else if (intr == -2 || intr == -3 || intr == -4) {
 432                 kvm_mips_callbacks->dequeue_io_int(dvcpu, irq);
 433         } else {
 434                 kvm_err("%s: invalid interrupt ioctl (%d:%d)\n", __func__,
 435                         irq->cpu, irq->irq);
 436                 return -EINVAL;
 437         }
 438
 439         dvcpu->arch.wait = 0;
 440
 441         if (waitqueue_active(&dvcpu->wq))
 442                 wake_up_interruptible(&dvcpu->wq);
 443
 444         return 0;
 445 }
 446
 447 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
 448                                     struct kvm_mp_state *mp_state)
 449 {
 450         return -ENOIOCTLCMD;
 451 }
 452
 453 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 454                                     struct kvm_mp_state *mp_state)
 455 {
 456         return -ENOIOCTLCMD;
 457 }
 458
 459 static u64 kvm_mips_get_one_regs[] = {
 460         KVM_REG_MIPS_R0,
 461         KVM_REG_MIPS_R1,
 462         KVM_REG_MIPS_R2,
 463         KVM_REG_MIPS_R3,
 464         KVM_REG_MIPS_R4,
 465         KVM_REG_MIPS_R5,
 466         KVM_REG_MIPS_R6,
 467         KVM_REG_MIPS_R7,
 468         KVM_REG_MIPS_R8,
 469         KVM_REG_MIPS_R9,
 470         KVM_REG_MIPS_R10,
 471         KVM_REG_MIPS_R11,
 472         KVM_REG_MIPS_R12,
 473         KVM_REG_MIPS_R13,
 474         KVM_REG_MIPS_R14,
 475         KVM_REG_MIPS_R15,
 476         KVM_REG_MIPS_R16,
 477         KVM_REG_MIPS_R17,
 478         KVM_REG_MIPS_R18,
 479         KVM_REG_MIPS_R19,
 480         KVM_REG_MIPS_R20,
 481         KVM_REG_MIPS_R21,
 482         KVM_REG_MIPS_R22,
 483         KVM_REG_MIPS_R23,
 484         KVM_REG_MIPS_R24,
 485         KVM_REG_MIPS_R25,
 486         KVM_REG_MIPS_R26,
 487         KVM_REG_MIPS_R27,
 488         KVM_REG_MIPS_R28,
 489         KVM_REG_MIPS_R29,
 490         KVM_REG_MIPS_R30,
 491         KVM_REG_MIPS_R31,
 492
 493         KVM_REG_MIPS_HI,
 494         KVM_REG_MIPS_LO,
 495         KVM_REG_MIPS_PC,
 496
 497         KVM_REG_MIPS_CP0_INDEX,
 498         KVM_REG_MIPS_CP0_CONTEXT,
 499         KVM_REG_MIPS_CP0_USERLOCAL,
 500         KVM_REG_MIPS_CP0_PAGEMASK,
 501         KVM_REG_MIPS_CP0_WIRED,
 502         KVM_REG_MIPS_CP0_HWRENA,
 503         KVM_REG_MIPS_CP0_BADVADDR,
 504         KVM_REG_MIPS_CP0_COUNT,
 505         KVM_REG_MIPS_CP0_ENTRYHI,
 506         KVM_REG_MIPS_CP0_COMPARE,
 507         KVM_REG_MIPS_CP0_STATUS,
 508         KVM_REG_MIPS_CP0_CAUSE,
 509         KVM_REG_MIPS_CP0_EPC,
 510         KVM_REG_MIPS_CP0_PRID,
 511         KVM_REG_MIPS_CP0_CONFIG,
 512         KVM_REG_MIPS_CP0_CONFIG1,
 513         KVM_REG_MIPS_CP0_CONFIG2,
 514         KVM_REG_MIPS_CP0_CONFIG3,
 515         KVM_REG_MIPS_CP0_CONFIG4,
 516         KVM_REG_MIPS_CP0_CONFIG5,
 517         KVM_REG_MIPS_CP0_CONFIG7,
 518         KVM_REG_MIPS_CP0_ERROREPC,
 519
 520         KVM_REG_MIPS_COUNT_CTL,
 521         KVM_REG_MIPS_COUNT_RESUME,
 522         KVM_REG_MIPS_COUNT_HZ,
 523 };
 524
 525 static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
 526                             const struct kvm_one_reg *reg)
 527 {
 528         struct mips_coproc *cop0 = vcpu->arch.cop0;
 529         int ret;
 530         s64 v;
 531
 532         switch (reg->id) {
 533         case KVM_REG_MIPS_R0 ... KVM_REG_MIPS_R31:
 534                 v = (long)vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0];
 535                 break;
 536         case KVM_REG_MIPS_HI:
 537                 v = (long)vcpu->arch.hi;
 538                 break;
 539         case KVM_REG_MIPS_LO:
 540                 v = (long)vcpu->arch.lo;
 541                 break;
 542         case KVM_REG_MIPS_PC:
 543                 v = (long)vcpu->arch.pc;
 544                 break;
 545
 546         case KVM_REG_MIPS_CP0_INDEX:
 547                 v = (long)kvm_read_c0_guest_index(cop0);
 548                 break;
 549         case KVM_REG_MIPS_CP0_CONTEXT:
 550                 v = (long)kvm_read_c0_guest_context(cop0);
 551                 break;
 552         case KVM_REG_MIPS_CP0_USERLOCAL:
 553                 v = (long)kvm_read_c0_guest_userlocal(cop0);
 554                 break;
 555         case KVM_REG_MIPS_CP0_PAGEMASK:
 556                 v = (long)kvm_read_c0_guest_pagemask(cop0);
 557                 break;
 558         case KVM_REG_MIPS_CP0_WIRED:
 559                 v = (long)kvm_read_c0_guest_wired(cop0);
 560                 break;
 561         case KVM_REG_MIPS_CP0_HWRENA:
 562                 v = (long)kvm_read_c0_guest_hwrena(cop0);
 563                 break;
 564         case KVM_REG_MIPS_CP0_BADVADDR:
 565                 v = (long)kvm_read_c0_guest_badvaddr(cop0);
 566                 break;
 567         case KVM_REG_MIPS_CP0_ENTRYHI:
 568                 v = (long)kvm_read_c0_guest_entryhi(cop0);
 569                 break;
 570         case KVM_REG_MIPS_CP0_COMPARE:
 571                 v = (long)kvm_read_c0_guest_compare(cop0);
 572                 break;
 573         case KVM_REG_MIPS_CP0_STATUS:
 574                 v = (long)kvm_read_c0_guest_status(cop0);
 575                 break;
 576         case KVM_REG_MIPS_CP0_CAUSE:
 577                 v = (long)kvm_read_c0_guest_cause(cop0);
 578                 break;
 579         case KVM_REG_MIPS_CP0_EPC:
 580                 v = (long)kvm_read_c0_guest_epc(cop0);
 581                 break;
 582         case KVM_REG_MIPS_CP0_PRID:
 583                 v = (long)kvm_read_c0_guest_prid(cop0);
 584                 break;
 585         case KVM_REG_MIPS_CP0_CONFIG:
 586                 v = (long)kvm_read_c0_guest_config(cop0);
 587                 break;
 588         case KVM_REG_MIPS_CP0_CONFIG1:
 589                 v = (long)kvm_read_c0_guest_config1(cop0);
 590                 break;
 591         case KVM_REG_MIPS_CP0_CONFIG2:
 592                 v = (long)kvm_read_c0_guest_config2(cop0);
 593                 break;
 594         case KVM_REG_MIPS_CP0_CONFIG3:
 595                 v = (long)kvm_read_c0_guest_config3(cop0);
 596                 break;
 597         case KVM_REG_MIPS_CP0_CONFIG4:
 598                 v = (long)kvm_read_c0_guest_config4(cop0);
 599                 break;
 600         case KVM_REG_MIPS_CP0_CONFIG5:
 601                 v = (long)kvm_read_c0_guest_config5(cop0);
 602                 break;
 603         case KVM_REG_MIPS_CP0_CONFIG7:
 604                 v = (long)kvm_read_c0_guest_config7(cop0);
 605                 break;
 606         case KVM_REG_MIPS_CP0_ERROREPC:
 607                 v = (long)kvm_read_c0_guest_errorepc(cop0);
 608                 break;
 609         /* registers to be handled specially */
 610         case KVM_REG_MIPS_CP0_COUNT:
 611         case KVM_REG_MIPS_COUNT_CTL:
 612         case KVM_REG_MIPS_COUNT_RESUME:
 613         case KVM_REG_MIPS_COUNT_HZ:
 614                 ret = kvm_mips_callbacks->get_one_reg(vcpu, reg, &v);
 615                 if (ret)
 616                         return ret;
 617                 break;
 618         default:
 619                 return -EINVAL;
 620         }
 621         if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U64) {
 622                 u64 __user *uaddr64 = (u64 __user *)(long)reg->addr;
 623
 624                 return put_user(v, uaddr64);
 625         } else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U32) {
 626                 u32 __user *uaddr32 = (u32 __user *)(long)reg->addr;
 627                 u32 v32 = (u32)v;
 628
 629                 return put_user(v32, uaddr32);
 630         } else {
 631                 return -EINVAL;
 632         }
 633 }
 634
 635 static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
 636                             const struct kvm_one_reg *reg)
 637 {
 638         struct mips_coproc *cop0 = vcpu->arch.cop0;
 639         u64 v;
 640
 641         if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U64) {
 642                 u64 __user *uaddr64 = (u64 __user *)(long)reg->addr;
 643
 644                 if (get_user(v, uaddr64) != 0)
 645                         return -EFAULT;
 646         } else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U32) {
 647                 u32 __user *uaddr32 = (u32 __user *)(long)reg->addr;
 648                 s32 v32;
 649
 650                 if (get_user(v32, uaddr32) != 0)
 651                         return -EFAULT;
 652                 v = (s64)v32;
 653         } else {
 654                 return -EINVAL;
 655         }
 656
 657         switch (reg->id) {
 658         case KVM_REG_MIPS_R0:
 659                 /* Silently ignore requests to set $0 */
 660                 break;
 661         case KVM_REG_MIPS_R1 ... KVM_REG_MIPS_R31:
 662                 vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0] = v;
 663                 break;
 664         case KVM_REG_MIPS_HI:
 665                 vcpu->arch.hi = v;
 666                 break;
 667         case KVM_REG_MIPS_LO:
 668                 vcpu->arch.lo = v;
 669                 break;
 670         case KVM_REG_MIPS_PC:
 671                 vcpu->arch.pc = v;
 672                 break;
 673
 674         case KVM_REG_MIPS_CP0_INDEX:
 675                 kvm_write_c0_guest_index(cop0, v);
 676                 break;
 677         case KVM_REG_MIPS_CP0_CONTEXT:
 678                 kvm_write_c0_guest_context(cop0, v);
 679                 break;
 680         case KVM_REG_MIPS_CP0_USERLOCAL:
 681                 kvm_write_c0_guest_userlocal(cop0, v);
 682                 break;
 683         case KVM_REG_MIPS_CP0_PAGEMASK:
 684                 kvm_write_c0_guest_pagemask(cop0, v);
 685                 break;
 686         case KVM_REG_MIPS_CP0_WIRED:
 687                 kvm_write_c0_guest_wired(cop0, v);
 688                 break;
 689         case KVM_REG_MIPS_CP0_HWRENA:
 690                 kvm_write_c0_guest_hwrena(cop0, v);
 691                 break;
 692         case KVM_REG_MIPS_CP0_BADVADDR:
 693                 kvm_write_c0_guest_badvaddr(cop0, v);
 694                 break;
 695         case KVM_REG_MIPS_CP0_ENTRYHI:
 696                 kvm_write_c0_guest_entryhi(cop0, v);
 697                 break;
 698         case KVM_REG_MIPS_CP0_STATUS:
 699                 kvm_write_c0_guest_status(cop0, v);
 700                 break;
 701         case KVM_REG_MIPS_CP0_EPC:
 702                 kvm_write_c0_guest_epc(cop0, v);
 703                 break;
 704         case KVM_REG_MIPS_CP0_PRID:
 705                 kvm_write_c0_guest_prid(cop0, v);
 706                 break;
 707         case KVM_REG_MIPS_CP0_ERROREPC:
 708                 kvm_write_c0_guest_errorepc(cop0, v);
 709                 break;
 710         /* registers to be handled specially */
 711         case KVM_REG_MIPS_CP0_COUNT:
 712         case KVM_REG_MIPS_CP0_COMPARE:
 713         case KVM_REG_MIPS_CP0_CAUSE:
 714         case KVM_REG_MIPS_CP0_CONFIG:
 715         case KVM_REG_MIPS_CP0_CONFIG1:
 716         case KVM_REG_MIPS_CP0_CONFIG2:
 717         case KVM_REG_MIPS_CP0_CONFIG3:
 718         case KVM_REG_MIPS_CP0_CONFIG4:
 719         case KVM_REG_MIPS_CP0_CONFIG5:
 720         case KVM_REG_MIPS_COUNT_CTL:
 721         case KVM_REG_MIPS_COUNT_RESUME:
 722         case KVM_REG_MIPS_COUNT_HZ:
 723                 return kvm_mips_callbacks->set_one_reg(vcpu, reg, v);
 724         default:
 725                 return -EINVAL;
 726         }
 727         return 0;
 728 }
 729
 730 long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl,
 731                          unsigned long arg)
 732 {
 733         struct kvm_vcpu *vcpu = filp->private_data;
 734         void __user *argp = (void __user *)arg;
 735         long r;
 736
 737         switch (ioctl) {
 738         case KVM_SET_ONE_REG:
 739         case KVM_GET_ONE_REG: {
 740                 struct kvm_one_reg reg;
 741
 742                 if (copy_from_user(&reg, argp, sizeof(reg)))
 743                         return -EFAULT;
 744                 if (ioctl == KVM_SET_ONE_REG)
 745                         return kvm_mips_set_reg(vcpu, &reg);
 746                 else
 747                         return kvm_mips_get_reg(vcpu, &reg);
 748         }
 749         case KVM_GET_REG_LIST: {
 750                 struct kvm_reg_list __user *user_list = argp;
 751                 u64 __user *reg_dest;
 752                 struct kvm_reg_list reg_list;
 753                 unsigned n;
 754
 755                 if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
 756                         return -EFAULT;
 757                 n = reg_list.n;
 758                 reg_list.n = ARRAY_SIZE(kvm_mips_get_one_regs);
 759                 if (copy_to_user(user_list, &reg_list, sizeof(reg_list)))
 760                         return -EFAULT;
 761                 if (n < reg_list.n)
 762                         return -E2BIG;
 763                 reg_dest = user_list->reg;
 764                 if (copy_to_user(reg_dest, kvm_mips_get_one_regs,
 765                                  sizeof(kvm_mips_get_one_regs)))
 766                         return -EFAULT;
 767                 return 0;
 768         }
 769         case KVM_NMI:
 770                 /* Treat the NMI as a CPU reset */
 771                 r = kvm_mips_reset_vcpu(vcpu);
 772                 break;
 773         case KVM_INTERRUPT:
 774                 {
 775                         struct kvm_mips_interrupt irq;
 776
 777                         r = -EFAULT;
 778                         if (copy_from_user(&irq, argp, sizeof(irq)))
 779                                 goto out;
 780
 781                         kvm_debug("[%d] %s: irq: %d\n", vcpu->vcpu_id, __func__,
 782                                   irq.irq);
 783
 784                         r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
 785                         break;
 786                 }
 787         default:
 788                 r = -ENOIOCTLCMD;
 789         }
 790
 791 out:
 792         return r;
 793 }
 794
 795 /* Get (and clear) the dirty memory log for a memory slot. */
 796 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
 797 {
 798         struct kvm_memory_slot *memslot;
 799         unsigned long ga, ga_end;
 800         int is_dirty = 0;
 801         int r;
 802         unsigned long n;
 803
 804         mutex_lock(&kvm->slots_lock);
 805
 806         r = kvm_get_dirty_log(kvm, log, &is_dirty);
 807         if (r)
 808                 goto out;
 809
 810         /* If nothing is dirty, don't bother messing with page tables. */
 811         if (is_dirty) {
 812                 memslot = &kvm->memslots->memslots[log->slot];
 813
 814                 ga = memslot->base_gfn << PAGE_SHIFT;
 815                 ga_end = ga + (memslot->npages << PAGE_SHIFT);
 816
 817                 kvm_info("%s: dirty, ga: %#lx, ga_end %#lx\n", __func__, ga,
 818                          ga_end);
 819
 820                 n = kvm_dirty_bitmap_bytes(memslot);
 821                 memset(memslot->dirty_bitmap, 0, n);
 822         }
 823
 824         r = 0;
 825 out:
 826         mutex_unlock(&kvm->slots_lock);
 827         return r;
 828
 829 }
 830
 831 long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
 832 {
 833         long r;
 834
 835         switch (ioctl) {
 836         default:
 837                 r = -ENOIOCTLCMD;
 838         }
 839
 840         return r;
 841 }
 842
 843 int kvm_arch_init(void *opaque)
 844 {
 845         if (kvm_mips_callbacks) {
 846                 kvm_err("kvm: module already exists\n");
 847                 return -EEXIST;
 848         }
 849
 850         return kvm_mips_emulation_init(&kvm_mips_callbacks);
 851 }
 852
 853 void kvm_arch_exit(void)
 854 {
 855         kvm_mips_callbacks = NULL;
 856 }
 857
 858 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 859                                   struct kvm_sregs *sregs)
 860 {
 861         return -ENOIOCTLCMD;
 862 }
 863
 864 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 865                                   struct kvm_sregs *sregs)
 866 {
 867         return -ENOIOCTLCMD;
 868 }
 869
 870 void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
 871 {
 872 }
 873
 874 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 875 {
 876         return -ENOIOCTLCMD;
 877 }
 878
 879 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 880 {
 881         return -ENOIOCTLCMD;
 882 }
 883
 884 int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
 885 {
 886         return VM_FAULT_SIGBUS;
 887 }
 888
 889 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 890 {
 891         int r;
 892
 893         switch (ext) {
 894         case KVM_CAP_ONE_REG:
 895                 r = 1;
 896                 break;
 897         case KVM_CAP_COALESCED_MMIO:
 898                 r = KVM_COALESCED_MMIO_PAGE_OFFSET;
 899                 break;
 900         default:
 901                 r = 0;
 902                 break;
 903         }
 904         return r;
 905 }
 906
 907 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 908 {
 909         return kvm_mips_pending_timer(vcpu);
 910 }
 911
 912 int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu)
 913 {
 914         int i;
 915         struct mips_coproc *cop0;
 916
 917         if (!vcpu)
 918                 return -1;
 919
 920         kvm_debug("VCPU Register Dump:\n");
 921         kvm_debug("\tpc = 0x%08lx\n", vcpu->arch.pc);
 922         kvm_debug("\texceptions: %08lx\n", vcpu->arch.pending_exceptions);
 923
 924         for (i = 0; i < 32; i += 4) {
 925                 kvm_debug("\tgpr%02d: %08lx %08lx %08lx %08lx\n", i,
 926                        vcpu->arch.gprs[i],
 927                        vcpu->arch.gprs[i + 1],
 928                        vcpu->arch.gprs[i + 2], vcpu->arch.gprs[i + 3]);
 929         }
 930         kvm_debug("\thi: 0x%08lx\n", vcpu->arch.hi);
 931         kvm_debug("\tlo: 0x%08lx\n", vcpu->arch.lo);
 932
 933         cop0 = vcpu->arch.cop0;
 934         kvm_debug("\tStatus: 0x%08lx, Cause: 0x%08lx\n",
 935                   kvm_read_c0_guest_status(cop0),
 936                   kvm_read_c0_guest_cause(cop0));
 937
 938         kvm_debug("\tEPC: 0x%08lx\n", kvm_read_c0_guest_epc(cop0));
 939
 940         return 0;
 941 }
 942
 943 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 944 {
 945         int i;
 946
 947         for (i = 1; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
 948                 vcpu->arch.gprs[i] = regs->gpr[i];
 949         vcpu->arch.gprs[0] = 0; /* zero is special, and cannot be set. */
 950         vcpu->arch.hi = regs->hi;
 951         vcpu->arch.lo = regs->lo;
 952         vcpu->arch.pc = regs->pc;
 953
 954         return 0;
 955 }
 956
 957 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 958 {
 959         int i;
 960
 961         for (i = 0; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
 962                 regs->gpr[i] = vcpu->arch.gprs[i];
 963
 964         regs->hi = vcpu->arch.hi;
 965         regs->lo = vcpu->arch.lo;
 966         regs->pc = vcpu->arch.pc;
 967
 968         return 0;
 969 }
 970
 971 static void kvm_mips_comparecount_func(unsigned long data)
 972 {
 973         struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
 974
 975         kvm_mips_callbacks->queue_timer_int(vcpu);
 976
 977         vcpu->arch.wait = 0;
 978         if (waitqueue_active(&vcpu->wq))
 979                 wake_up_interruptible(&vcpu->wq);
 980 }
 981
 982 /* low level hrtimer wake routine */
 983 static enum hrtimer_restart kvm_mips_comparecount_wakeup(struct hrtimer *timer)
 984 {
 985         struct kvm_vcpu *vcpu;
 986
 987         vcpu = container_of(timer, struct kvm_vcpu, arch.comparecount_timer);
 988         kvm_mips_comparecount_func((unsigned long) vcpu);
 989         return kvm_mips_count_timeout(vcpu);
 990 }
 991
 992 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 993 {
 994         kvm_mips_callbacks->vcpu_init(vcpu);
 995         hrtimer_init(&vcpu->arch.comparecount_timer, CLOCK_MONOTONIC,
 996                      HRTIMER_MODE_REL);
 997         vcpu->arch.comparecount_timer.function = kvm_mips_comparecount_wakeup;
 998         return 0;
 999 }
1000
1001 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
1002                                   struct kvm_translation *tr)
1003 {
1004         return 0;
1005 }
1006
1007 /* Initial guest state */
1008 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
1009 {
1010         return kvm_mips_callbacks->vcpu_setup(vcpu);
1011 }
1012
1013 static void kvm_mips_set_c0_status(void)
1014 {
1015         uint32_t status = read_c0_status();
1016
1017         if (cpu_has_dsp)
1018                 status |= (ST0_MX);
1019
1020         write_c0_status(status);
1021         ehb();
1022 }
1023
1024 /*
1025  * Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
1026  */
1027 int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
1028 {
1029         uint32_t cause = vcpu->arch.host_cp0_cause;
1030         uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
1031         uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
1032         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
1033         enum emulation_result er = EMULATE_DONE;
1034         int ret = RESUME_GUEST;
1035
1036         /* re-enable HTW before enabling interrupts */
1037         htw_start();
1038
1039         /* Set a default exit reason */
1040         run->exit_reason = KVM_EXIT_UNKNOWN;
1041         run->ready_for_interrupt_injection = 1;
1042
1043         /*
1044          * Set the appropriate status bits based on host CPU features,
1045          * before we hit the scheduler
1046          */
1047         kvm_mips_set_c0_status();
1048
1049         local_irq_enable();
1050
1051         kvm_debug("kvm_mips_handle_exit: cause: %#x, PC: %p, kvm_run: %p, kvm_vcpu: %p\n",
1052                         cause, opc, run, vcpu);
1053
1054         /*
1055          * Do a privilege check, if in UM most of these exit conditions end up
1056          * causing an exception to be delivered to the Guest Kernel
1057          */
1058         er = kvm_mips_check_privilege(cause, opc, run, vcpu);
1059         if (er == EMULATE_PRIV_FAIL) {
1060                 goto skip_emul;
1061         } else if (er == EMULATE_FAIL) {
1062                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
1063                 ret = RESUME_HOST;
1064                 goto skip_emul;
1065         }
1066
1067         switch (exccode) {
1068         case T_INT:
1069                 kvm_debug("[%d]T_INT @ %p\n", vcpu->vcpu_id, opc);
1070
1071                 ++vcpu->stat.int_exits;
1072                 trace_kvm_exit(vcpu, INT_EXITS);
1073
1074                 if (need_resched())
1075                         cond_resched();
1076
1077                 ret = RESUME_GUEST;
1078                 break;
1079
1080         case T_COP_UNUSABLE:
1081                 kvm_debug("T_COP_UNUSABLE: @ PC: %p\n", opc);
1082
1083                 ++vcpu->stat.cop_unusable_exits;
1084                 trace_kvm_exit(vcpu, COP_UNUSABLE_EXITS);
1085                 ret = kvm_mips_callbacks->handle_cop_unusable(vcpu);
1086                 /* XXXKYMA: Might need to return to user space */
1087                 if (run->exit_reason == KVM_EXIT_IRQ_WINDOW_OPEN)
1088                         ret = RESUME_HOST;
1089                 break;
1090
1091         case T_TLB_MOD:
1092                 ++vcpu->stat.tlbmod_exits;
1093                 trace_kvm_exit(vcpu, TLBMOD_EXITS);
1094                 ret = kvm_mips_callbacks->handle_tlb_mod(vcpu);
1095                 break;
1096
1097         case T_TLB_ST_MISS:
1098                 kvm_debug("TLB ST fault:  cause %#x, status %#lx, PC: %p, BadVaddr: %#lx\n",
1099                           cause, kvm_read_c0_guest_status(vcpu->arch.cop0), opc,
1100                           badvaddr);
1101
1102                 ++vcpu->stat.tlbmiss_st_exits;
1103                 trace_kvm_exit(vcpu, TLBMISS_ST_EXITS);
1104                 ret = kvm_mips_callbacks->handle_tlb_st_miss(vcpu);
1105                 break;
1106
1107         case T_TLB_LD_MISS:
1108                 kvm_debug("TLB LD fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
1109                           cause, opc, badvaddr);
1110
1111                 ++vcpu->stat.tlbmiss_ld_exits;
1112                 trace_kvm_exit(vcpu, TLBMISS_LD_EXITS);
1113                 ret = kvm_mips_callbacks->handle_tlb_ld_miss(vcpu);
1114                 break;
1115
1116         case T_ADDR_ERR_ST:
1117                 ++vcpu->stat.addrerr_st_exits;
1118                 trace_kvm_exit(vcpu, ADDRERR_ST_EXITS);
1119                 ret = kvm_mips_callbacks->handle_addr_err_st(vcpu);
1120                 break;
1121
1122         case T_ADDR_ERR_LD:
1123                 ++vcpu->stat.addrerr_ld_exits;
1124                 trace_kvm_exit(vcpu, ADDRERR_LD_EXITS);
1125                 ret = kvm_mips_callbacks->handle_addr_err_ld(vcpu);
1126                 break;
1127
1128         case T_SYSCALL:
1129                 ++vcpu->stat.syscall_exits;
1130                 trace_kvm_exit(vcpu, SYSCALL_EXITS);
1131                 ret = kvm_mips_callbacks->handle_syscall(vcpu);
1132                 break;
1133
1134         case T_RES_INST:
1135                 ++vcpu->stat.resvd_inst_exits;
1136                 trace_kvm_exit(vcpu, RESVD_INST_EXITS);
1137                 ret = kvm_mips_callbacks->handle_res_inst(vcpu);
1138                 break;
1139
1140         case T_BREAK:
1141                 ++vcpu->stat.break_inst_exits;
1142                 trace_kvm_exit(vcpu, BREAK_INST_EXITS);
1143                 ret = kvm_mips_callbacks->handle_break(vcpu);
1144                 break;
1145
1146         case T_TRAP:
1147                 ++vcpu->stat.trap_inst_exits;
1148                 trace_kvm_exit(vcpu, TRAP_INST_EXITS);
1149                 ret = kvm_mips_callbacks->handle_trap(vcpu);
1150                 break;
1151
1152         case T_FPE:
1153                 ++vcpu->stat.fpe_exits;
1154                 trace_kvm_exit(vcpu, FPE_EXITS);
1155                 ret = kvm_mips_callbacks->handle_fpe(vcpu);
1156                 break;
1157
1158         case T_MSADIS:
1159                 ret = kvm_mips_callbacks->handle_msa_disabled(vcpu);
1160                 break;
1161
1162         default:
1163                 kvm_err("Exception Code: %d, not yet handled, @ PC: %p, inst: 0x%08x  BadVaddr: %#lx Status: %#lx\n",
1164                         exccode, opc, kvm_get_inst(opc, vcpu), badvaddr,
1165                         kvm_read_c0_guest_status(vcpu->arch.cop0));
1166                 kvm_arch_vcpu_dump_regs(vcpu);
1167                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
1168                 ret = RESUME_HOST;
1169                 break;
1170
1171         }
1172
1173 skip_emul:
1174         local_irq_disable();
1175
1176         if (er == EMULATE_DONE && !(ret & RESUME_HOST))
1177                 kvm_mips_deliver_interrupts(vcpu, cause);
1178
1179         if (!(ret & RESUME_HOST)) {
1180                 /* Only check for signals if not already exiting to userspace */
1181                 if (signal_pending(current)) {
1182                         run->exit_reason = KVM_EXIT_INTR;
1183                         ret = (-EINTR << 2) | RESUME_HOST;
1184                         ++vcpu->stat.signal_exits;
1185                         trace_kvm_exit(vcpu, SIGNAL_EXITS);
1186                 }
1187         }
1188
1189         if (ret == RESUME_GUEST) {
1190                 /*
1191                  * If FPU is enabled (i.e. the guest's FPU context is live),
1192                  * restore FCR31.
1193                  *
1194                  * This should be before returning to the guest exception
1195                  * vector, as it may well cause an FP exception if there are
1196                  * pending exception bits unmasked. (see
1197                  * kvm_mips_csr_die_notifier() for how that is handled).
1198                  */
1199                 if (kvm_mips_guest_has_fpu(&vcpu->arch) &&
1200                     read_c0_status() & ST0_CU1)
1201                         __kvm_restore_fcsr(&vcpu->arch);
1202         }
1203
1204         /* Disable HTW before returning to guest or host */
1205         htw_stop();
1206
1207         return ret;
1208 }
1209
1210 /* Enable FPU for guest and restore context */
1211 void kvm_own_fpu(struct kvm_vcpu *vcpu)
1212 {
1213         struct mips_coproc *cop0 = vcpu->arch.cop0;
1214         unsigned int sr, cfg5;
1215
1216         preempt_disable();
1217
1218         /*
1219          * Enable FPU for guest
1220          * We set FR and FRE according to guest context
1221          */
1222         sr = kvm_read_c0_guest_status(cop0);
1223         change_c0_status(ST0_CU1 | ST0_FR, sr);
1224         if (cpu_has_fre) {
1225                 cfg5 = kvm_read_c0_guest_config5(cop0);
1226                 change_c0_config5(MIPS_CONF5_FRE, cfg5);
1227         }
1228         enable_fpu_hazard();
1229
1230         /* If guest FPU state not active, restore it now */
1231         if (!(vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)) {
1232                 __kvm_restore_fpu(&vcpu->arch);
1233                 vcpu->arch.fpu_inuse |= KVM_MIPS_FPU_FPU;
1234         }
1235
1236         preempt_enable();
1237 }
1238
1239 /* Drop FPU without saving it */
1240 void kvm_drop_fpu(struct kvm_vcpu *vcpu)
1241 {
1242         preempt_disable();
1243         if (vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU) {
1244                 clear_c0_status(ST0_CU1 | ST0_FR);
1245                 vcpu->arch.fpu_inuse &= ~KVM_MIPS_FPU_FPU;
1246         }
1247         preempt_enable();
1248 }
1249
1250 /* Save and disable FPU */
1251 void kvm_lose_fpu(struct kvm_vcpu *vcpu)
1252 {
1253         /*
1254          * FPU gets disabled in root context (hardware) when it is disabled in
1255          * guest context (software), but the register state in the hardware may
1256          * still be in use. This is why we explicitly re-enable the hardware
1257          * before saving.
1258          */
1259
1260         preempt_disable();
1261         if (vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU) {
1262                 set_c0_status(ST0_CU1);
1263                 enable_fpu_hazard();
1264
1265                 __kvm_save_fpu(&vcpu->arch);
1266                 vcpu->arch.fpu_inuse &= ~KVM_MIPS_FPU_FPU;
1267
1268                 /* Disable FPU */
1269                 clear_c0_status(ST0_CU1 | ST0_FR);
1270         }
1271         preempt_enable();
1272 }
1273
1274 /*
1275  * Step over a specific ctc1 to FCSR which is used to restore guest FCSR state
1276  * and may trigger a "harmless" FP exception if cause bits are set in the value
1277  * being written.
1278  */
1279 static int kvm_mips_csr_die_notify(struct notifier_block *self,
1280                                    unsigned long cmd, void *ptr)
1281 {
1282         struct die_args *args = (struct die_args *)ptr;
1283         struct pt_regs *regs = args->regs;
1284         unsigned long pc;
1285
1286         /* Only interested in FPE */
1287         if (cmd != DIE_FP)
1288                 return NOTIFY_DONE;
1289
1290         /* Return immediately if guest context isn't active */
1291         if (!(current->flags & PF_VCPU))
1292                 return NOTIFY_DONE;
1293
1294         /* Should never get here from user mode */
1295         BUG_ON(user_mode(regs));
1296
1297         pc = instruction_pointer(regs);
1298         switch (cmd) {
1299         case DIE_FP:
1300                 /* match 2nd instruction in __kvm_restore_fcsr */
1301                 if (pc != (unsigned long)&__kvm_restore_fcsr + 4)
1302                         return NOTIFY_DONE;
1303                 break;
1304         }
1305
1306         /* Move PC forward a little and continue executing */
1307         instruction_pointer(regs) += 4;
1308
1309         return NOTIFY_STOP;
1310 }
1311
1312 static struct notifier_block kvm_mips_csr_die_notifier = {
1313         .notifier_call = kvm_mips_csr_die_notify,
1314 };
1315
1316 int __init kvm_mips_init(void)
1317 {
1318         int ret;
1319
1320         ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
1321
1322         if (ret)
1323                 return ret;
1324
1325         register_die_notifier(&kvm_mips_csr_die_notifier);
1326
1327         /*
1328          * On MIPS, kernel modules are executed from "mapped space", which
1329          * requires TLBs. The TLB handling code is statically linked with
1330          * the rest of the kernel (tlb.c) to avoid the possibility of
1331          * double faulting. The issue is that the TLB code references
1332          * routines that are part of the the KVM module, which are only
1333          * available once the module is loaded.
1334          */
1335         kvm_mips_gfn_to_pfn = gfn_to_pfn;
1336         kvm_mips_release_pfn_clean = kvm_release_pfn_clean;
1337         kvm_mips_is_error_pfn = is_error_pfn;
1338
1339         return 0;
1340 }
1341
1342 void __exit kvm_mips_exit(void)
1343 {
1344         kvm_exit();
1345
1346         kvm_mips_gfn_to_pfn = NULL;
1347         kvm_mips_release_pfn_clean = NULL;
1348         kvm_mips_is_error_pfn = NULL;
1349
1350         unregister_die_notifier(&kvm_mips_csr_die_notifier);
1351 }
1352
1353 module_init(kvm_mips_init);
1354 module_exit(kvm_mips_exit);
1355
1356 EXPORT_TRACEPOINT_SYMBOL(kvm_exit);