arch/mips/kvm/trap_emul.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: Deliver/Emulate exceptions to the guest kernel
   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/vmalloc.h>
  15
  16 #include <linux/kvm_host.h>
  17
  18 #include "interrupt.h"
  19
  20 static gpa_t kvm_trap_emul_gva_to_gpa_cb(gva_t gva)
  21 {
  22         gpa_t gpa;
  23         gva_t kseg = KSEGX(gva);
  24
  25         if ((kseg == CKSEG0) || (kseg == CKSEG1))
  26                 gpa = CPHYSADDR(gva);
  27         else {
  28                 kvm_err("%s: cannot find GPA for GVA: %#lx\n", __func__, gva);
  29                 kvm_mips_dump_host_tlbs();
  30                 gpa = KVM_INVALID_ADDR;
  31         }
  32
  33         kvm_debug("%s: gva %#lx, gpa: %#llx\n", __func__, gva, gpa);
  34
  35         return gpa;
  36 }
  37
  38 static int kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu *vcpu)
  39 {
  40         struct mips_coproc *cop0 = vcpu->arch.cop0;
  41         struct kvm_run *run = vcpu->run;
  42         u32 __user *opc = (u32 __user *) vcpu->arch.pc;
  43         u32 cause = vcpu->arch.host_cp0_cause;
  44         enum emulation_result er = EMULATE_DONE;
  45         int ret = RESUME_GUEST;
  46
  47         if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
  48                 /* FPU Unusable */
  49                 if (!kvm_mips_guest_has_fpu(&vcpu->arch) ||
  50                     (kvm_read_c0_guest_status(cop0) & ST0_CU1) == 0) {
  51                         /*
  52                          * Unusable/no FPU in guest:
  53                          * deliver guest COP1 Unusable Exception
  54                          */
  55                         er = kvm_mips_emulate_fpu_exc(cause, opc, run, vcpu);
  56                 } else {
  57                         /* Restore FPU state */
  58                         kvm_own_fpu(vcpu);
  59                         er = EMULATE_DONE;
  60                 }
  61         } else {
  62                 er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
  63         }
  64
  65         switch (er) {
  66         case EMULATE_DONE:
  67                 ret = RESUME_GUEST;
  68                 break;
  69
  70         case EMULATE_FAIL:
  71                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
  72                 ret = RESUME_HOST;
  73                 break;
  74
  75         case EMULATE_WAIT:
  76                 run->exit_reason = KVM_EXIT_INTR;
  77                 ret = RESUME_HOST;
  78                 break;
  79
  80         default:
  81                 BUG();
  82         }
  83         return ret;
  84 }
  85
  86 static int kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu *vcpu)
  87 {
  88         struct kvm_run *run = vcpu->run;
  89         u32 __user *opc = (u32 __user *) vcpu->arch.pc;
  90         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
  91         u32 cause = vcpu->arch.host_cp0_cause;
  92         enum emulation_result er = EMULATE_DONE;
  93         int ret = RESUME_GUEST;
  94
  95         if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
  96             || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
  97                 kvm_debug("USER/KSEG23 ADDR TLB MOD fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
  98                           cause, opc, badvaddr);
  99                 er = kvm_mips_handle_tlbmod(cause, opc, run, vcpu);
 100
 101                 if (er == EMULATE_DONE)
 102                         ret = RESUME_GUEST;
 103                 else {
 104                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 105                         ret = RESUME_HOST;
 106                 }
 107         } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
 108                 /*
 109                  * XXXKYMA: The guest kernel does not expect to get this fault
 110                  * when we are not using HIGHMEM. Need to address this in a
 111                  * HIGHMEM kernel
 112                  */
 113                 kvm_err("TLB MOD fault not handled, cause %#x, PC: %p, BadVaddr: %#lx\n",
 114                         cause, opc, badvaddr);
 115                 kvm_mips_dump_host_tlbs();
 116                 kvm_arch_vcpu_dump_regs(vcpu);
 117                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 118                 ret = RESUME_HOST;
 119         } else {
 120                 kvm_err("Illegal TLB Mod fault address , cause %#x, PC: %p, BadVaddr: %#lx\n",
 121                         cause, opc, badvaddr);
 122                 kvm_mips_dump_host_tlbs();
 123                 kvm_arch_vcpu_dump_regs(vcpu);
 124                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 125                 ret = RESUME_HOST;
 126         }
 127         return ret;
 128 }
 129
 130 static int kvm_trap_emul_handle_tlb_miss(struct kvm_vcpu *vcpu, bool store)
 131 {
 132         struct kvm_run *run = vcpu->run;
 133         u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 134         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 135         u32 cause = vcpu->arch.host_cp0_cause;
 136         enum emulation_result er = EMULATE_DONE;
 137         int ret = RESUME_GUEST;
 138
 139         if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
 140             && KVM_GUEST_KERNEL_MODE(vcpu)) {
 141                 if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
 142                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 143                         ret = RESUME_HOST;
 144                 }
 145         } else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
 146                    || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
 147                 kvm_debug("USER ADDR TLB %s fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
 148                           store ? "ST" : "LD", cause, opc, badvaddr);
 149
 150                 /*
 151                  * User Address (UA) fault, this could happen if
 152                  * (1) TLB entry not present/valid in both Guest and shadow host
 153                  *     TLBs, in this case we pass on the fault to the guest
 154                  *     kernel and let it handle it.
 155                  * (2) TLB entry is present in the Guest TLB but not in the
 156                  *     shadow, in this case we inject the TLB from the Guest TLB
 157                  *     into the shadow host TLB
 158                  */
 159
 160                 er = kvm_mips_handle_tlbmiss(cause, opc, run, vcpu);
 161                 if (er == EMULATE_DONE)
 162                         ret = RESUME_GUEST;
 163                 else {
 164                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 165                         ret = RESUME_HOST;
 166                 }
 167         } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
 168                 /*
 169                  * All KSEG0 faults are handled by KVM, as the guest kernel does
 170                  * not expect to ever get them
 171                  */
 172                 if (kvm_mips_handle_kseg0_tlb_fault
 173                     (vcpu->arch.host_cp0_badvaddr, vcpu) < 0) {
 174                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 175                         ret = RESUME_HOST;
 176                 }
 177         } else if (KVM_GUEST_KERNEL_MODE(vcpu)
 178                    && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
 179                 /*
 180                  * With EVA we may get a TLB exception instead of an address
 181                  * error when the guest performs MMIO to KSeg1 addresses.
 182                  */
 183                 kvm_debug("Emulate %s MMIO space\n",
 184                           store ? "Store to" : "Load from");
 185                 er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
 186                 if (er == EMULATE_FAIL) {
 187                         kvm_err("Emulate %s MMIO space failed\n",
 188                                 store ? "Store to" : "Load from");
 189                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 190                         ret = RESUME_HOST;
 191                 } else {
 192                         run->exit_reason = KVM_EXIT_MMIO;
 193                         ret = RESUME_HOST;
 194                 }
 195         } else {
 196                 kvm_err("Illegal TLB %s fault address , cause %#x, PC: %p, BadVaddr: %#lx\n",
 197                         store ? "ST" : "LD", cause, opc, badvaddr);
 198                 kvm_mips_dump_host_tlbs();
 199                 kvm_arch_vcpu_dump_regs(vcpu);
 200                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 201                 ret = RESUME_HOST;
 202         }
 203         return ret;
 204 }
 205
 206 static int kvm_trap_emul_handle_tlb_st_miss(struct kvm_vcpu *vcpu)
 207 {
 208         return kvm_trap_emul_handle_tlb_miss(vcpu, true);
 209 }
 210
 211 static int kvm_trap_emul_handle_tlb_ld_miss(struct kvm_vcpu *vcpu)
 212 {
 213         return kvm_trap_emul_handle_tlb_miss(vcpu, false);
 214 }
 215
 216 static int kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu *vcpu)
 217 {
 218         struct kvm_run *run = vcpu->run;
 219         u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 220         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 221         u32 cause = vcpu->arch.host_cp0_cause;
 222         enum emulation_result er = EMULATE_DONE;
 223         int ret = RESUME_GUEST;
 224
 225         if (KVM_GUEST_KERNEL_MODE(vcpu)
 226             && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
 227                 kvm_debug("Emulate Store to MMIO space\n");
 228                 er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
 229                 if (er == EMULATE_FAIL) {
 230                         kvm_err("Emulate Store to MMIO space failed\n");
 231                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 232                         ret = RESUME_HOST;
 233                 } else {
 234                         run->exit_reason = KVM_EXIT_MMIO;
 235                         ret = RESUME_HOST;
 236                 }
 237         } else {
 238                 kvm_err("Address Error (STORE): cause %#x, PC: %p, BadVaddr: %#lx\n",
 239                         cause, opc, badvaddr);
 240                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 241                 ret = RESUME_HOST;
 242         }
 243         return ret;
 244 }
 245
 246 static int kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu *vcpu)
 247 {
 248         struct kvm_run *run = vcpu->run;
 249         u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 250         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 251         u32 cause = vcpu->arch.host_cp0_cause;
 252         enum emulation_result er = EMULATE_DONE;
 253         int ret = RESUME_GUEST;
 254
 255         if (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1) {
 256                 kvm_debug("Emulate Load from MMIO space @ %#lx\n", badvaddr);
 257                 er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
 258                 if (er == EMULATE_FAIL) {
 259                         kvm_err("Emulate Load from MMIO space failed\n");
 260                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 261                         ret = RESUME_HOST;
 262                 } else {
 263                         run->exit_reason = KVM_EXIT_MMIO;
 264                         ret = RESUME_HOST;
 265                 }
 266         } else {
 267                 kvm_err("Address Error (LOAD): cause %#x, PC: %p, BadVaddr: %#lx\n",
 268                         cause, opc, badvaddr);
 269                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 270                 ret = RESUME_HOST;
 271                 er = EMULATE_FAIL;
 272         }
 273         return ret;
 274 }
 275
 276 static int kvm_trap_emul_handle_syscall(struct kvm_vcpu *vcpu)
 277 {
 278         struct kvm_run *run = vcpu->run;
 279         u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 280         u32 cause = vcpu->arch.host_cp0_cause;
 281         enum emulation_result er = EMULATE_DONE;
 282         int ret = RESUME_GUEST;
 283
 284         er = kvm_mips_emulate_syscall(cause, opc, run, vcpu);
 285         if (er == EMULATE_DONE)
 286                 ret = RESUME_GUEST;
 287         else {
 288                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 289                 ret = RESUME_HOST;
 290         }
 291         return ret;
 292 }
 293
 294 static int kvm_trap_emul_handle_res_inst(struct kvm_vcpu *vcpu)
 295 {
 296         struct kvm_run *run = vcpu->run;
 297         u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 298         u32 cause = vcpu->arch.host_cp0_cause;
 299         enum emulation_result er = EMULATE_DONE;
 300         int ret = RESUME_GUEST;
 301
 302         er = kvm_mips_handle_ri(cause, opc, run, vcpu);
 303         if (er == EMULATE_DONE)
 304                 ret = RESUME_GUEST;
 305         else {
 306                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 307                 ret = RESUME_HOST;
 308         }
 309         return ret;
 310 }
 311
 312 static int kvm_trap_emul_handle_break(struct kvm_vcpu *vcpu)
 313 {
 314         struct kvm_run *run = vcpu->run;
 315         u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 316         u32 cause = vcpu->arch.host_cp0_cause;
 317         enum emulation_result er = EMULATE_DONE;
 318         int ret = RESUME_GUEST;
 319
 320         er = kvm_mips_emulate_bp_exc(cause, opc, run, vcpu);
 321         if (er == EMULATE_DONE)
 322                 ret = RESUME_GUEST;
 323         else {
 324                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 325                 ret = RESUME_HOST;
 326         }
 327         return ret;
 328 }
 329
 330 static int kvm_trap_emul_handle_trap(struct kvm_vcpu *vcpu)
 331 {
 332         struct kvm_run *run = vcpu->run;
 333         u32 __user *opc = (u32 __user *)vcpu->arch.pc;
 334         u32 cause = vcpu->arch.host_cp0_cause;
 335         enum emulation_result er = EMULATE_DONE;
 336         int ret = RESUME_GUEST;
 337
 338         er = kvm_mips_emulate_trap_exc(cause, opc, run, vcpu);
 339         if (er == EMULATE_DONE) {
 340                 ret = RESUME_GUEST;
 341         } else {
 342                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 343                 ret = RESUME_HOST;
 344         }
 345         return ret;
 346 }
 347
 348 static int kvm_trap_emul_handle_msa_fpe(struct kvm_vcpu *vcpu)
 349 {
 350         struct kvm_run *run = vcpu->run;
 351         u32 __user *opc = (u32 __user *)vcpu->arch.pc;
 352         u32 cause = vcpu->arch.host_cp0_cause;
 353         enum emulation_result er = EMULATE_DONE;
 354         int ret = RESUME_GUEST;
 355
 356         er = kvm_mips_emulate_msafpe_exc(cause, opc, run, vcpu);
 357         if (er == EMULATE_DONE) {
 358                 ret = RESUME_GUEST;
 359         } else {
 360                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 361                 ret = RESUME_HOST;
 362         }
 363         return ret;
 364 }
 365
 366 static int kvm_trap_emul_handle_fpe(struct kvm_vcpu *vcpu)
 367 {
 368         struct kvm_run *run = vcpu->run;
 369         u32 __user *opc = (u32 __user *)vcpu->arch.pc;
 370         u32 cause = vcpu->arch.host_cp0_cause;
 371         enum emulation_result er = EMULATE_DONE;
 372         int ret = RESUME_GUEST;
 373
 374         er = kvm_mips_emulate_fpe_exc(cause, opc, run, vcpu);
 375         if (er == EMULATE_DONE) {
 376                 ret = RESUME_GUEST;
 377         } else {
 378                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 379                 ret = RESUME_HOST;
 380         }
 381         return ret;
 382 }
 383
 384 /**
 385  * kvm_trap_emul_handle_msa_disabled() - Guest used MSA while disabled in root.
 386  * @vcpu:       Virtual CPU context.
 387  *
 388  * Handle when the guest attempts to use MSA when it is disabled.
 389  */
 390 static int kvm_trap_emul_handle_msa_disabled(struct kvm_vcpu *vcpu)
 391 {
 392         struct mips_coproc *cop0 = vcpu->arch.cop0;
 393         struct kvm_run *run = vcpu->run;
 394         u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 395         u32 cause = vcpu->arch.host_cp0_cause;
 396         enum emulation_result er = EMULATE_DONE;
 397         int ret = RESUME_GUEST;
 398
 399         if (!kvm_mips_guest_has_msa(&vcpu->arch) ||
 400             (kvm_read_c0_guest_status(cop0) & (ST0_CU1 | ST0_FR)) == ST0_CU1) {
 401                 /*
 402                  * No MSA in guest, or FPU enabled and not in FR=1 mode,
 403                  * guest reserved instruction exception
 404                  */
 405                 er = kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
 406         } else if (!(kvm_read_c0_guest_config5(cop0) & MIPS_CONF5_MSAEN)) {
 407                 /* MSA disabled by guest, guest MSA disabled exception */
 408                 er = kvm_mips_emulate_msadis_exc(cause, opc, run, vcpu);
 409         } else {
 410                 /* Restore MSA/FPU state */
 411                 kvm_own_msa(vcpu);
 412                 er = EMULATE_DONE;
 413         }
 414
 415         switch (er) {
 416         case EMULATE_DONE:
 417                 ret = RESUME_GUEST;
 418                 break;
 419
 420         case EMULATE_FAIL:
 421                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 422                 ret = RESUME_HOST;
 423                 break;
 424
 425         default:
 426                 BUG();
 427         }
 428         return ret;
 429 }
 430
 431 static int kvm_trap_emul_vm_init(struct kvm *kvm)
 432 {
 433         return 0;
 434 }
 435
 436 static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu)
 437 {
 438         vcpu->arch.kscratch_enabled = 0xfc;
 439
 440         return 0;
 441 }
 442
 443 static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)
 444 {
 445         struct mips_coproc *cop0 = vcpu->arch.cop0;
 446         u32 config, config1;
 447         int vcpu_id = vcpu->vcpu_id;
 448
 449         /*
 450          * Arch specific stuff, set up config registers properly so that the
 451          * guest will come up as expected
 452          */
 453 #ifndef CONFIG_CPU_MIPSR6
 454         /* r2-r5, simulate a MIPS 24kc */
 455         kvm_write_c0_guest_prid(cop0, 0x00019300);
 456 #else
 457         /* r6+, simulate a generic QEMU machine */
 458         kvm_write_c0_guest_prid(cop0, 0x00010000);
 459 #endif
 460         /*
 461          * Have config1, Cacheable, noncoherent, write-back, write allocate.
 462          * Endianness, arch revision & virtually tagged icache should match
 463          * host.
 464          */
 465         config = read_c0_config() & MIPS_CONF_AR;
 466         config |= MIPS_CONF_M | CONF_CM_CACHABLE_NONCOHERENT | MIPS_CONF_MT_TLB;
 467 #ifdef CONFIG_CPU_BIG_ENDIAN
 468         config |= CONF_BE;
 469 #endif
 470         if (cpu_has_vtag_icache)
 471                 config |= MIPS_CONF_VI;
 472         kvm_write_c0_guest_config(cop0, config);
 473
 474         /* Read the cache characteristics from the host Config1 Register */
 475         config1 = (read_c0_config1() & ~0x7f);
 476
 477         /* Set up MMU size */
 478         config1 &= ~(0x3f << 25);
 479         config1 |= ((KVM_MIPS_GUEST_TLB_SIZE - 1) << 25);
 480
 481         /* We unset some bits that we aren't emulating */
 482         config1 &= ~(MIPS_CONF1_C2 | MIPS_CONF1_MD | MIPS_CONF1_PC |
 483                      MIPS_CONF1_WR | MIPS_CONF1_CA);
 484         kvm_write_c0_guest_config1(cop0, config1);
 485
 486         /* Have config3, no tertiary/secondary caches implemented */
 487         kvm_write_c0_guest_config2(cop0, MIPS_CONF_M);
 488         /* MIPS_CONF_M | (read_c0_config2() & 0xfff) */
 489
 490         /* Have config4, UserLocal */
 491         kvm_write_c0_guest_config3(cop0, MIPS_CONF_M | MIPS_CONF3_ULRI);
 492
 493         /* Have config5 */
 494         kvm_write_c0_guest_config4(cop0, MIPS_CONF_M);
 495
 496         /* No config6 */
 497         kvm_write_c0_guest_config5(cop0, 0);
 498
 499         /* Set Wait IE/IXMT Ignore in Config7, IAR, AR */
 500         kvm_write_c0_guest_config7(cop0, (MIPS_CONF7_WII) | (1 << 10));
 501
 502         /*
 503          * Setup IntCtl defaults, compatibility mode for timer interrupts (HW5)
 504          */
 505         kvm_write_c0_guest_intctl(cop0, 0xFC000000);
 506
 507         /* Put in vcpu id as CPUNum into Ebase Reg to handle SMP Guests */
 508         kvm_write_c0_guest_ebase(cop0, KVM_GUEST_KSEG0 |
 509                                        (vcpu_id & MIPS_EBASE_CPUNUM));
 510
 511         return 0;
 512 }
 513
 514 static unsigned long kvm_trap_emul_num_regs(struct kvm_vcpu *vcpu)
 515 {
 516         return 0;
 517 }
 518
 519 static int kvm_trap_emul_copy_reg_indices(struct kvm_vcpu *vcpu,
 520                                           u64 __user *indices)
 521 {
 522         return 0;
 523 }
 524
 525 static int kvm_trap_emul_get_one_reg(struct kvm_vcpu *vcpu,
 526                                      const struct kvm_one_reg *reg,
 527                                      s64 *v)
 528 {
 529         switch (reg->id) {
 530         case KVM_REG_MIPS_CP0_COUNT:
 531                 *v = kvm_mips_read_count(vcpu);
 532                 break;
 533         case KVM_REG_MIPS_COUNT_CTL:
 534                 *v = vcpu->arch.count_ctl;
 535                 break;
 536         case KVM_REG_MIPS_COUNT_RESUME:
 537                 *v = ktime_to_ns(vcpu->arch.count_resume);
 538                 break;
 539         case KVM_REG_MIPS_COUNT_HZ:
 540                 *v = vcpu->arch.count_hz;
 541                 break;
 542         default:
 543                 return -EINVAL;
 544         }
 545         return 0;
 546 }
 547
 548 static int kvm_trap_emul_set_one_reg(struct kvm_vcpu *vcpu,
 549                                      const struct kvm_one_reg *reg,
 550                                      s64 v)
 551 {
 552         struct mips_coproc *cop0 = vcpu->arch.cop0;
 553         int ret = 0;
 554         unsigned int cur, change;
 555
 556         switch (reg->id) {
 557         case KVM_REG_MIPS_CP0_COUNT:
 558                 kvm_mips_write_count(vcpu, v);
 559                 break;
 560         case KVM_REG_MIPS_CP0_COMPARE:
 561                 kvm_mips_write_compare(vcpu, v, false);
 562                 break;
 563         case KVM_REG_MIPS_CP0_CAUSE:
 564                 /*
 565                  * If the timer is stopped or started (DC bit) it must look
 566                  * atomic with changes to the interrupt pending bits (TI, IRQ5).
 567                  * A timer interrupt should not happen in between.
 568                  */
 569                 if ((kvm_read_c0_guest_cause(cop0) ^ v) & CAUSEF_DC) {
 570                         if (v & CAUSEF_DC) {
 571                                 /* disable timer first */
 572                                 kvm_mips_count_disable_cause(vcpu);
 573                                 kvm_change_c0_guest_cause(cop0, ~CAUSEF_DC, v);
 574                         } else {
 575                                 /* enable timer last */
 576                                 kvm_change_c0_guest_cause(cop0, ~CAUSEF_DC, v);
 577                                 kvm_mips_count_enable_cause(vcpu);
 578                         }
 579                 } else {
 580                         kvm_write_c0_guest_cause(cop0, v);
 581                 }
 582                 break;
 583         case KVM_REG_MIPS_CP0_CONFIG:
 584                 /* read-only for now */
 585                 break;
 586         case KVM_REG_MIPS_CP0_CONFIG1:
 587                 cur = kvm_read_c0_guest_config1(cop0);
 588                 change = (cur ^ v) & kvm_mips_config1_wrmask(vcpu);
 589                 if (change) {
 590                         v = cur ^ change;
 591                         kvm_write_c0_guest_config1(cop0, v);
 592                 }
 593                 break;
 594         case KVM_REG_MIPS_CP0_CONFIG2:
 595                 /* read-only for now */
 596                 break;
 597         case KVM_REG_MIPS_CP0_CONFIG3:
 598                 cur = kvm_read_c0_guest_config3(cop0);
 599                 change = (cur ^ v) & kvm_mips_config3_wrmask(vcpu);
 600                 if (change) {
 601                         v = cur ^ change;
 602                         kvm_write_c0_guest_config3(cop0, v);
 603                 }
 604                 break;
 605         case KVM_REG_MIPS_CP0_CONFIG4:
 606                 cur = kvm_read_c0_guest_config4(cop0);
 607                 change = (cur ^ v) & kvm_mips_config4_wrmask(vcpu);
 608                 if (change) {
 609                         v = cur ^ change;
 610                         kvm_write_c0_guest_config4(cop0, v);
 611                 }
 612                 break;
 613         case KVM_REG_MIPS_CP0_CONFIG5:
 614                 cur = kvm_read_c0_guest_config5(cop0);
 615                 change = (cur ^ v) & kvm_mips_config5_wrmask(vcpu);
 616                 if (change) {
 617                         v = cur ^ change;
 618                         kvm_write_c0_guest_config5(cop0, v);
 619                 }
 620                 break;
 621         case KVM_REG_MIPS_COUNT_CTL:
 622                 ret = kvm_mips_set_count_ctl(vcpu, v);
 623                 break;
 624         case KVM_REG_MIPS_COUNT_RESUME:
 625                 ret = kvm_mips_set_count_resume(vcpu, v);
 626                 break;
 627         case KVM_REG_MIPS_COUNT_HZ:
 628                 ret = kvm_mips_set_count_hz(vcpu, v);
 629                 break;
 630         default:
 631                 return -EINVAL;
 632         }
 633         return ret;
 634 }
 635
 636 static int kvm_trap_emul_vcpu_get_regs(struct kvm_vcpu *vcpu)
 637 {
 638         kvm_lose_fpu(vcpu);
 639
 640         return 0;
 641 }
 642
 643 static int kvm_trap_emul_vcpu_set_regs(struct kvm_vcpu *vcpu)
 644 {
 645         return 0;
 646 }
 647
 648 static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
 649         /* exit handlers */
 650         .handle_cop_unusable = kvm_trap_emul_handle_cop_unusable,
 651         .handle_tlb_mod = kvm_trap_emul_handle_tlb_mod,
 652         .handle_tlb_st_miss = kvm_trap_emul_handle_tlb_st_miss,
 653         .handle_tlb_ld_miss = kvm_trap_emul_handle_tlb_ld_miss,
 654         .handle_addr_err_st = kvm_trap_emul_handle_addr_err_st,
 655         .handle_addr_err_ld = kvm_trap_emul_handle_addr_err_ld,
 656         .handle_syscall = kvm_trap_emul_handle_syscall,
 657         .handle_res_inst = kvm_trap_emul_handle_res_inst,
 658         .handle_break = kvm_trap_emul_handle_break,
 659         .handle_trap = kvm_trap_emul_handle_trap,
 660         .handle_msa_fpe = kvm_trap_emul_handle_msa_fpe,
 661         .handle_fpe = kvm_trap_emul_handle_fpe,
 662         .handle_msa_disabled = kvm_trap_emul_handle_msa_disabled,
 663
 664         .vm_init = kvm_trap_emul_vm_init,
 665         .vcpu_init = kvm_trap_emul_vcpu_init,
 666         .vcpu_setup = kvm_trap_emul_vcpu_setup,
 667         .gva_to_gpa = kvm_trap_emul_gva_to_gpa_cb,
 668         .queue_timer_int = kvm_mips_queue_timer_int_cb,
 669         .dequeue_timer_int = kvm_mips_dequeue_timer_int_cb,
 670         .queue_io_int = kvm_mips_queue_io_int_cb,
 671         .dequeue_io_int = kvm_mips_dequeue_io_int_cb,
 672         .irq_deliver = kvm_mips_irq_deliver_cb,
 673         .irq_clear = kvm_mips_irq_clear_cb,
 674         .num_regs = kvm_trap_emul_num_regs,
 675         .copy_reg_indices = kvm_trap_emul_copy_reg_indices,
 676         .get_one_reg = kvm_trap_emul_get_one_reg,
 677         .set_one_reg = kvm_trap_emul_set_one_reg,
 678         .vcpu_get_regs = kvm_trap_emul_vcpu_get_regs,
 679         .vcpu_set_regs = kvm_trap_emul_vcpu_set_regs,
 680 };
 681
 682 int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
 683 {
 684         *install_callbacks = &kvm_trap_emul_callbacks;
 685         return 0;
 686 }