arch/mips/kvm/emulate.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: Instruction/Exception emulation
   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/ktime.h>
  15 #include <linux/kvm_host.h>
  16 #include <linux/module.h>
  17 #include <linux/vmalloc.h>
  18 #include <linux/fs.h>
  19 #include <linux/bootmem.h>
  20 #include <linux/random.h>
  21 #include <asm/page.h>
  22 #include <asm/cacheflush.h>
  23 #include <asm/cacheops.h>
  24 #include <asm/cpu-info.h>
  25 #include <asm/mmu_context.h>
  26 #include <asm/tlbflush.h>
  27 #include <asm/inst.h>
  28
  29 #undef CONFIG_MIPS_MT
  30 #include <asm/r4kcache.h>
  31 #define CONFIG_MIPS_MT
  32
  33 #include "interrupt.h"
  34 #include "commpage.h"
  35
  36 #include "trace.h"
  37
  38 /*
  39  * Compute the return address and do emulate branch simulation, if required.
  40  * This function should be called only in branch delay slot active.
  41  */
  42 unsigned long kvm_compute_return_epc(struct kvm_vcpu *vcpu,
  43         unsigned long instpc)
  44 {
  45         unsigned int dspcontrol;
  46         union mips_instruction insn;
  47         struct kvm_vcpu_arch *arch = &vcpu->arch;
  48         long epc = instpc;
  49         long nextpc = KVM_INVALID_INST;
  50
  51         if (epc & 3)
  52                 goto unaligned;
  53
  54         /* Read the instruction */
  55         insn.word = kvm_get_inst((uint32_t *) epc, vcpu);
  56
  57         if (insn.word == KVM_INVALID_INST)
  58                 return KVM_INVALID_INST;
  59
  60         switch (insn.i_format.opcode) {
  61                 /* jr and jalr are in r_format format. */
  62         case spec_op:
  63                 switch (insn.r_format.func) {
  64                 case jalr_op:
  65                         arch->gprs[insn.r_format.rd] = epc + 8;
  66                         /* Fall through */
  67                 case jr_op:
  68                         nextpc = arch->gprs[insn.r_format.rs];
  69                         break;
  70                 }
  71                 break;
  72
  73                 /*
  74                  * This group contains:
  75                  * bltz_op, bgez_op, bltzl_op, bgezl_op,
  76                  * bltzal_op, bgezal_op, bltzall_op, bgezall_op.
  77                  */
  78         case bcond_op:
  79                 switch (insn.i_format.rt) {
  80                 case bltz_op:
  81                 case bltzl_op:
  82                         if ((long)arch->gprs[insn.i_format.rs] < 0)
  83                                 epc = epc + 4 + (insn.i_format.simmediate << 2);
  84                         else
  85                                 epc += 8;
  86                         nextpc = epc;
  87                         break;
  88
  89                 case bgez_op:
  90                 case bgezl_op:
  91                         if ((long)arch->gprs[insn.i_format.rs] >= 0)
  92                                 epc = epc + 4 + (insn.i_format.simmediate << 2);
  93                         else
  94                                 epc += 8;
  95                         nextpc = epc;
  96                         break;
  97
  98                 case bltzal_op:
  99                 case bltzall_op:
 100                         arch->gprs[31] = epc + 8;
 101                         if ((long)arch->gprs[insn.i_format.rs] < 0)
 102                                 epc = epc + 4 + (insn.i_format.simmediate << 2);
 103                         else
 104                                 epc += 8;
 105                         nextpc = epc;
 106                         break;
 107
 108                 case bgezal_op:
 109                 case bgezall_op:
 110                         arch->gprs[31] = epc + 8;
 111                         if ((long)arch->gprs[insn.i_format.rs] >= 0)
 112                                 epc = epc + 4 + (insn.i_format.simmediate << 2);
 113                         else
 114                                 epc += 8;
 115                         nextpc = epc;
 116                         break;
 117                 case bposge32_op:
 118                         if (!cpu_has_dsp)
 119                                 goto sigill;
 120
 121                         dspcontrol = rddsp(0x01);
 122
 123                         if (dspcontrol >= 32)
 124                                 epc = epc + 4 + (insn.i_format.simmediate << 2);
 125                         else
 126                                 epc += 8;
 127                         nextpc = epc;
 128                         break;
 129                 }
 130                 break;
 131
 132                 /* These are unconditional and in j_format. */
 133         case jal_op:
 134                 arch->gprs[31] = instpc + 8;
 135         case j_op:
 136                 epc += 4;
 137                 epc >>= 28;
 138                 epc <<= 28;
 139                 epc |= (insn.j_format.target << 2);
 140                 nextpc = epc;
 141                 break;
 142
 143                 /* These are conditional and in i_format. */
 144         case beq_op:
 145         case beql_op:
 146                 if (arch->gprs[insn.i_format.rs] ==
 147                     arch->gprs[insn.i_format.rt])
 148                         epc = epc + 4 + (insn.i_format.simmediate << 2);
 149                 else
 150                         epc += 8;
 151                 nextpc = epc;
 152                 break;
 153
 154         case bne_op:
 155         case bnel_op:
 156                 if (arch->gprs[insn.i_format.rs] !=
 157                     arch->gprs[insn.i_format.rt])
 158                         epc = epc + 4 + (insn.i_format.simmediate << 2);
 159                 else
 160                         epc += 8;
 161                 nextpc = epc;
 162                 break;
 163
 164         case blez_op:           /* not really i_format */
 165         case blezl_op:
 166                 /* rt field assumed to be zero */
 167                 if ((long)arch->gprs[insn.i_format.rs] <= 0)
 168                         epc = epc + 4 + (insn.i_format.simmediate << 2);
 169                 else
 170                         epc += 8;
 171                 nextpc = epc;
 172                 break;
 173
 174         case bgtz_op:
 175         case bgtzl_op:
 176                 /* rt field assumed to be zero */
 177                 if ((long)arch->gprs[insn.i_format.rs] > 0)
 178                         epc = epc + 4 + (insn.i_format.simmediate << 2);
 179                 else
 180                         epc += 8;
 181                 nextpc = epc;
 182                 break;
 183
 184                 /* And now the FPA/cp1 branch instructions. */
 185         case cop1_op:
 186                 kvm_err("%s: unsupported cop1_op\n", __func__);
 187                 break;
 188         }
 189
 190         return nextpc;
 191
 192 unaligned:
 193         kvm_err("%s: unaligned epc\n", __func__);
 194         return nextpc;
 195
 196 sigill:
 197         kvm_err("%s: DSP branch but not DSP ASE\n", __func__);
 198         return nextpc;
 199 }
 200
 201 enum emulation_result update_pc(struct kvm_vcpu *vcpu, uint32_t cause)
 202 {
 203         unsigned long branch_pc;
 204         enum emulation_result er = EMULATE_DONE;
 205
 206         if (cause & CAUSEF_BD) {
 207                 branch_pc = kvm_compute_return_epc(vcpu, vcpu->arch.pc);
 208                 if (branch_pc == KVM_INVALID_INST) {
 209                         er = EMULATE_FAIL;
 210                 } else {
 211                         vcpu->arch.pc = branch_pc;
 212                         kvm_debug("BD update_pc(): New PC: %#lx\n",
 213                                   vcpu->arch.pc);
 214                 }
 215         } else
 216                 vcpu->arch.pc += 4;
 217
 218         kvm_debug("update_pc(): New PC: %#lx\n", vcpu->arch.pc);
 219
 220         return er;
 221 }
 222
 223 /**
 224  * kvm_mips_count_disabled() - Find whether the CP0_Count timer is disabled.
 225  * @vcpu:       Virtual CPU.
 226  *
 227  * Returns:     1 if the CP0_Count timer is disabled by either the guest
 228  *              CP0_Cause.DC bit or the count_ctl.DC bit.
 229  *              0 otherwise (in which case CP0_Count timer is running).
 230  */
 231 static inline int kvm_mips_count_disabled(struct kvm_vcpu *vcpu)
 232 {
 233         struct mips_coproc *cop0 = vcpu->arch.cop0;
 234
 235         return  (vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) ||
 236                 (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC);
 237 }
 238
 239 /**
 240  * kvm_mips_ktime_to_count() - Scale ktime_t to a 32-bit count.
 241  *
 242  * Caches the dynamic nanosecond bias in vcpu->arch.count_dyn_bias.
 243  *
 244  * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
 245  */
 246 static uint32_t kvm_mips_ktime_to_count(struct kvm_vcpu *vcpu, ktime_t now)
 247 {
 248         s64 now_ns, periods;
 249         u64 delta;
 250
 251         now_ns = ktime_to_ns(now);
 252         delta = now_ns + vcpu->arch.count_dyn_bias;
 253
 254         if (delta >= vcpu->arch.count_period) {
 255                 /* If delta is out of safe range the bias needs adjusting */
 256                 periods = div64_s64(now_ns, vcpu->arch.count_period);
 257                 vcpu->arch.count_dyn_bias = -periods * vcpu->arch.count_period;
 258                 /* Recalculate delta with new bias */
 259                 delta = now_ns + vcpu->arch.count_dyn_bias;
 260         }
 261
 262         /*
 263          * We've ensured that:
 264          *   delta < count_period
 265          *
 266          * Therefore the intermediate delta*count_hz will never overflow since
 267          * at the boundary condition:
 268          *   delta = count_period
 269          *   delta = NSEC_PER_SEC * 2^32 / count_hz
 270          *   delta * count_hz = NSEC_PER_SEC * 2^32
 271          */
 272         return div_u64(delta * vcpu->arch.count_hz, NSEC_PER_SEC);
 273 }
 274
 275 /**
 276  * kvm_mips_count_time() - Get effective current time.
 277  * @vcpu:       Virtual CPU.
 278  *
 279  * Get effective monotonic ktime. This is usually a straightforward ktime_get(),
 280  * except when the master disable bit is set in count_ctl, in which case it is
 281  * count_resume, i.e. the time that the count was disabled.
 282  *
 283  * Returns:     Effective monotonic ktime for CP0_Count.
 284  */
 285 static inline ktime_t kvm_mips_count_time(struct kvm_vcpu *vcpu)
 286 {
 287         if (unlikely(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC))
 288                 return vcpu->arch.count_resume;
 289
 290         return ktime_get();
 291 }
 292
 293 /**
 294  * kvm_mips_read_count_running() - Read the current count value as if running.
 295  * @vcpu:       Virtual CPU.
 296  * @now:        Kernel time to read CP0_Count at.
 297  *
 298  * Returns the current guest CP0_Count register at time @now and handles if the
 299  * timer interrupt is pending and hasn't been handled yet.
 300  *
 301  * Returns:     The current value of the guest CP0_Count register.
 302  */
 303 static uint32_t kvm_mips_read_count_running(struct kvm_vcpu *vcpu, ktime_t now)
 304 {
 305         ktime_t expires;
 306         int running;
 307
 308         /* Is the hrtimer pending? */
 309         expires = hrtimer_get_expires(&vcpu->arch.comparecount_timer);
 310         if (ktime_compare(now, expires) >= 0) {
 311                 /*
 312                  * Cancel it while we handle it so there's no chance of
 313                  * interference with the timeout handler.
 314                  */
 315                 running = hrtimer_cancel(&vcpu->arch.comparecount_timer);
 316
 317                 /* Nothing should be waiting on the timeout */
 318                 kvm_mips_callbacks->queue_timer_int(vcpu);
 319
 320                 /*
 321                  * Restart the timer if it was running based on the expiry time
 322                  * we read, so that we don't push it back 2 periods.
 323                  */
 324                 if (running) {
 325                         expires = ktime_add_ns(expires,
 326                                                vcpu->arch.count_period);
 327                         hrtimer_start(&vcpu->arch.comparecount_timer, expires,
 328                                       HRTIMER_MODE_ABS);
 329                 }
 330         }
 331
 332         /* Return the biased and scaled guest CP0_Count */
 333         return vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now);
 334 }
 335
 336 /**
 337  * kvm_mips_read_count() - Read the current count value.
 338  * @vcpu:       Virtual CPU.
 339  *
 340  * Read the current guest CP0_Count value, taking into account whether the timer
 341  * is stopped.
 342  *
 343  * Returns:     The current guest CP0_Count value.
 344  */
 345 uint32_t kvm_mips_read_count(struct kvm_vcpu *vcpu)
 346 {
 347         struct mips_coproc *cop0 = vcpu->arch.cop0;
 348
 349         /* If count disabled just read static copy of count */
 350         if (kvm_mips_count_disabled(vcpu))
 351                 return kvm_read_c0_guest_count(cop0);
 352
 353         return kvm_mips_read_count_running(vcpu, ktime_get());
 354 }
 355
 356 /**
 357  * kvm_mips_freeze_hrtimer() - Safely stop the hrtimer.
 358  * @vcpu:       Virtual CPU.
 359  * @count:      Output pointer for CP0_Count value at point of freeze.
 360  *
 361  * Freeze the hrtimer safely and return both the ktime and the CP0_Count value
 362  * at the point it was frozen. It is guaranteed that any pending interrupts at
 363  * the point it was frozen are handled, and none after that point.
 364  *
 365  * This is useful where the time/CP0_Count is needed in the calculation of the
 366  * new parameters.
 367  *
 368  * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
 369  *
 370  * Returns:     The ktime at the point of freeze.
 371  */
 372 static ktime_t kvm_mips_freeze_hrtimer(struct kvm_vcpu *vcpu,
 373                                        uint32_t *count)
 374 {
 375         ktime_t now;
 376
 377         /* stop hrtimer before finding time */
 378         hrtimer_cancel(&vcpu->arch.comparecount_timer);
 379         now = ktime_get();
 380
 381         /* find count at this point and handle pending hrtimer */
 382         *count = kvm_mips_read_count_running(vcpu, now);
 383
 384         return now;
 385 }
 386
 387 /**
 388  * kvm_mips_resume_hrtimer() - Resume hrtimer, updating expiry.
 389  * @vcpu:       Virtual CPU.
 390  * @now:        ktime at point of resume.
 391  * @count:      CP0_Count at point of resume.
 392  *
 393  * Resumes the timer and updates the timer expiry based on @now and @count.
 394  * This can be used in conjunction with kvm_mips_freeze_timer() when timer
 395  * parameters need to be changed.
 396  *
 397  * It is guaranteed that a timer interrupt immediately after resume will be
 398  * handled, but not if CP_Compare is exactly at @count. That case is already
 399  * handled by kvm_mips_freeze_timer().
 400  *
 401  * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
 402  */
 403 static void kvm_mips_resume_hrtimer(struct kvm_vcpu *vcpu,
 404                                     ktime_t now, uint32_t count)
 405 {
 406         struct mips_coproc *cop0 = vcpu->arch.cop0;
 407         uint32_t compare;
 408         u64 delta;
 409         ktime_t expire;
 410
 411         /* Calculate timeout (wrap 0 to 2^32) */
 412         compare = kvm_read_c0_guest_compare(cop0);
 413         delta = (u64)(uint32_t)(compare - count - 1) + 1;
 414         delta = div_u64(delta * NSEC_PER_SEC, vcpu->arch.count_hz);
 415         expire = ktime_add_ns(now, delta);
 416
 417         /* Update hrtimer to use new timeout */
 418         hrtimer_cancel(&vcpu->arch.comparecount_timer);
 419         hrtimer_start(&vcpu->arch.comparecount_timer, expire, HRTIMER_MODE_ABS);
 420 }
 421
 422 /**
 423  * kvm_mips_update_hrtimer() - Update next expiry time of hrtimer.
 424  * @vcpu:       Virtual CPU.
 425  *
 426  * Recalculates and updates the expiry time of the hrtimer. This can be used
 427  * after timer parameters have been altered which do not depend on the time that
 428  * the change occurs (in those cases kvm_mips_freeze_hrtimer() and
 429  * kvm_mips_resume_hrtimer() are used directly).
 430  *
 431  * It is guaranteed that no timer interrupts will be lost in the process.
 432  *
 433  * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
 434  */
 435 static void kvm_mips_update_hrtimer(struct kvm_vcpu *vcpu)
 436 {
 437         ktime_t now;
 438         uint32_t count;
 439
 440         /*
 441          * freeze_hrtimer takes care of a timer interrupts <= count, and
 442          * resume_hrtimer the hrtimer takes care of a timer interrupts > count.
 443          */
 444         now = kvm_mips_freeze_hrtimer(vcpu, &count);
 445         kvm_mips_resume_hrtimer(vcpu, now, count);
 446 }
 447
 448 /**
 449  * kvm_mips_write_count() - Modify the count and update timer.
 450  * @vcpu:       Virtual CPU.
 451  * @count:      Guest CP0_Count value to set.
 452  *
 453  * Sets the CP0_Count value and updates the timer accordingly.
 454  */
 455 void kvm_mips_write_count(struct kvm_vcpu *vcpu, uint32_t count)
 456 {
 457         struct mips_coproc *cop0 = vcpu->arch.cop0;
 458         ktime_t now;
 459
 460         /* Calculate bias */
 461         now = kvm_mips_count_time(vcpu);
 462         vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now);
 463
 464         if (kvm_mips_count_disabled(vcpu))
 465                 /* The timer's disabled, adjust the static count */
 466                 kvm_write_c0_guest_count(cop0, count);
 467         else
 468                 /* Update timeout */
 469                 kvm_mips_resume_hrtimer(vcpu, now, count);
 470 }
 471
 472 /**
 473  * kvm_mips_init_count() - Initialise timer.
 474  * @vcpu:       Virtual CPU.
 475  *
 476  * Initialise the timer to a sensible frequency, namely 100MHz, zero it, and set
 477  * it going if it's enabled.
 478  */
 479 void kvm_mips_init_count(struct kvm_vcpu *vcpu)
 480 {
 481         /* 100 MHz */
 482         vcpu->arch.count_hz = 100*1000*1000;
 483         vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32,
 484                                           vcpu->arch.count_hz);
 485         vcpu->arch.count_dyn_bias = 0;
 486
 487         /* Starting at 0 */
 488         kvm_mips_write_count(vcpu, 0);
 489 }
 490
 491 /**
 492  * kvm_mips_set_count_hz() - Update the frequency of the timer.
 493  * @vcpu:       Virtual CPU.
 494  * @count_hz:   Frequency of CP0_Count timer in Hz.
 495  *
 496  * Change the frequency of the CP0_Count timer. This is done atomically so that
 497  * CP0_Count is continuous and no timer interrupt is lost.
 498  *
 499  * Returns:     -EINVAL if @count_hz is out of range.
 500  *              0 on success.
 501  */
 502 int kvm_mips_set_count_hz(struct kvm_vcpu *vcpu, s64 count_hz)
 503 {
 504         struct mips_coproc *cop0 = vcpu->arch.cop0;
 505         int dc;
 506         ktime_t now;
 507         u32 count;
 508
 509         /* ensure the frequency is in a sensible range... */
 510         if (count_hz <= 0 || count_hz > NSEC_PER_SEC)
 511                 return -EINVAL;
 512         /* ... and has actually changed */
 513         if (vcpu->arch.count_hz == count_hz)
 514                 return 0;
 515
 516         /* Safely freeze timer so we can keep it continuous */
 517         dc = kvm_mips_count_disabled(vcpu);
 518         if (dc) {
 519                 now = kvm_mips_count_time(vcpu);
 520                 count = kvm_read_c0_guest_count(cop0);
 521         } else {
 522                 now = kvm_mips_freeze_hrtimer(vcpu, &count);
 523         }
 524
 525         /* Update the frequency */
 526         vcpu->arch.count_hz = count_hz;
 527         vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32, count_hz);
 528         vcpu->arch.count_dyn_bias = 0;
 529
 530         /* Calculate adjusted bias so dynamic count is unchanged */
 531         vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now);
 532
 533         /* Update and resume hrtimer */
 534         if (!dc)
 535                 kvm_mips_resume_hrtimer(vcpu, now, count);
 536         return 0;
 537 }
 538
 539 /**
 540  * kvm_mips_write_compare() - Modify compare and update timer.
 541  * @vcpu:       Virtual CPU.
 542  * @compare:    New CP0_Compare value.
 543  *
 544  * Update CP0_Compare to a new value and update the timeout.
 545  */
 546 void kvm_mips_write_compare(struct kvm_vcpu *vcpu, uint32_t compare)
 547 {
 548         struct mips_coproc *cop0 = vcpu->arch.cop0;
 549
 550         /* if unchanged, must just be an ack */
 551         if (kvm_read_c0_guest_compare(cop0) == compare)
 552                 return;
 553
 554         /* Update compare */
 555         kvm_write_c0_guest_compare(cop0, compare);
 556
 557         /* Update timeout if count enabled */
 558         if (!kvm_mips_count_disabled(vcpu))
 559                 kvm_mips_update_hrtimer(vcpu);
 560 }
 561
 562 /**
 563  * kvm_mips_count_disable() - Disable count.
 564  * @vcpu:       Virtual CPU.
 565  *
 566  * Disable the CP0_Count timer. A timer interrupt on or before the final stop
 567  * time will be handled but not after.
 568  *
 569  * Assumes CP0_Count was previously enabled but now Guest.CP0_Cause.DC or
 570  * count_ctl.DC has been set (count disabled).
 571  *
 572  * Returns:     The time that the timer was stopped.
 573  */
 574 static ktime_t kvm_mips_count_disable(struct kvm_vcpu *vcpu)
 575 {
 576         struct mips_coproc *cop0 = vcpu->arch.cop0;
 577         uint32_t count;
 578         ktime_t now;
 579
 580         /* Stop hrtimer */
 581         hrtimer_cancel(&vcpu->arch.comparecount_timer);
 582
 583         /* Set the static count from the dynamic count, handling pending TI */
 584         now = ktime_get();
 585         count = kvm_mips_read_count_running(vcpu, now);
 586         kvm_write_c0_guest_count(cop0, count);
 587
 588         return now;
 589 }
 590
 591 /**
 592  * kvm_mips_count_disable_cause() - Disable count using CP0_Cause.DC.
 593  * @vcpu:       Virtual CPU.
 594  *
 595  * Disable the CP0_Count timer and set CP0_Cause.DC. A timer interrupt on or
 596  * before the final stop time will be handled if the timer isn't disabled by
 597  * count_ctl.DC, but not after.
 598  *
 599  * Assumes CP0_Cause.DC is clear (count enabled).
 600  */
 601 void kvm_mips_count_disable_cause(struct kvm_vcpu *vcpu)
 602 {
 603         struct mips_coproc *cop0 = vcpu->arch.cop0;
 604
 605         kvm_set_c0_guest_cause(cop0, CAUSEF_DC);
 606         if (!(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC))
 607                 kvm_mips_count_disable(vcpu);
 608 }
 609
 610 /**
 611  * kvm_mips_count_enable_cause() - Enable count using CP0_Cause.DC.
 612  * @vcpu:       Virtual CPU.
 613  *
 614  * Enable the CP0_Count timer and clear CP0_Cause.DC. A timer interrupt after
 615  * the start time will be handled if the timer isn't disabled by count_ctl.DC,
 616  * potentially before even returning, so the caller should be careful with
 617  * ordering of CP0_Cause modifications so as not to lose it.
 618  *
 619  * Assumes CP0_Cause.DC is set (count disabled).
 620  */
 621 void kvm_mips_count_enable_cause(struct kvm_vcpu *vcpu)
 622 {
 623         struct mips_coproc *cop0 = vcpu->arch.cop0;
 624         uint32_t count;
 625
 626         kvm_clear_c0_guest_cause(cop0, CAUSEF_DC);
 627
 628         /*
 629          * Set the dynamic count to match the static count.
 630          * This starts the hrtimer if count_ctl.DC allows it.
 631          * Otherwise it conveniently updates the biases.
 632          */
 633         count = kvm_read_c0_guest_count(cop0);
 634         kvm_mips_write_count(vcpu, count);
 635 }
 636
 637 /**
 638  * kvm_mips_set_count_ctl() - Update the count control KVM register.
 639  * @vcpu:       Virtual CPU.
 640  * @count_ctl:  Count control register new value.
 641  *
 642  * Set the count control KVM register. The timer is updated accordingly.
 643  *
 644  * Returns:     -EINVAL if reserved bits are set.
 645  *              0 on success.
 646  */
 647 int kvm_mips_set_count_ctl(struct kvm_vcpu *vcpu, s64 count_ctl)
 648 {
 649         struct mips_coproc *cop0 = vcpu->arch.cop0;
 650         s64 changed = count_ctl ^ vcpu->arch.count_ctl;
 651         s64 delta;
 652         ktime_t expire, now;
 653         uint32_t count, compare;
 654
 655         /* Only allow defined bits to be changed */
 656         if (changed & ~(s64)(KVM_REG_MIPS_COUNT_CTL_DC))
 657                 return -EINVAL;
 658
 659         /* Apply new value */
 660         vcpu->arch.count_ctl = count_ctl;
 661
 662         /* Master CP0_Count disable */
 663         if (changed & KVM_REG_MIPS_COUNT_CTL_DC) {
 664                 /* Is CP0_Cause.DC already disabling CP0_Count? */
 665                 if (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC) {
 666                         if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC)
 667                                 /* Just record the current time */
 668                                 vcpu->arch.count_resume = ktime_get();
 669                 } else if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) {
 670                         /* disable timer and record current time */
 671                         vcpu->arch.count_resume = kvm_mips_count_disable(vcpu);
 672                 } else {
 673                         /*
 674                          * Calculate timeout relative to static count at resume
 675                          * time (wrap 0 to 2^32).
 676                          */
 677                         count = kvm_read_c0_guest_count(cop0);
 678                         compare = kvm_read_c0_guest_compare(cop0);
 679                         delta = (u64)(uint32_t)(compare - count - 1) + 1;
 680                         delta = div_u64(delta * NSEC_PER_SEC,
 681                                         vcpu->arch.count_hz);
 682                         expire = ktime_add_ns(vcpu->arch.count_resume, delta);
 683
 684                         /* Handle pending interrupt */
 685                         now = ktime_get();
 686                         if (ktime_compare(now, expire) >= 0)
 687                                 /* Nothing should be waiting on the timeout */
 688                                 kvm_mips_callbacks->queue_timer_int(vcpu);
 689
 690                         /* Resume hrtimer without changing bias */
 691                         count = kvm_mips_read_count_running(vcpu, now);
 692                         kvm_mips_resume_hrtimer(vcpu, now, count);
 693                 }
 694         }
 695
 696         return 0;
 697 }
 698
 699 /**
 700  * kvm_mips_set_count_resume() - Update the count resume KVM register.
 701  * @vcpu:               Virtual CPU.
 702  * @count_resume:       Count resume register new value.
 703  *
 704  * Set the count resume KVM register.
 705  *
 706  * Returns:     -EINVAL if out of valid range (0..now).
 707  *              0 on success.
 708  */
 709 int kvm_mips_set_count_resume(struct kvm_vcpu *vcpu, s64 count_resume)
 710 {
 711         /*
 712          * It doesn't make sense for the resume time to be in the future, as it
 713          * would be possible for the next interrupt to be more than a full
 714          * period in the future.
 715          */
 716         if (count_resume < 0 || count_resume > ktime_to_ns(ktime_get()))
 717                 return -EINVAL;
 718
 719         vcpu->arch.count_resume = ns_to_ktime(count_resume);
 720         return 0;
 721 }
 722
 723 /**
 724  * kvm_mips_count_timeout() - Push timer forward on timeout.
 725  * @vcpu:       Virtual CPU.
 726  *
 727  * Handle an hrtimer event by push the hrtimer forward a period.
 728  *
 729  * Returns:     The hrtimer_restart value to return to the hrtimer subsystem.
 730  */
 731 enum hrtimer_restart kvm_mips_count_timeout(struct kvm_vcpu *vcpu)
 732 {
 733         /* Add the Count period to the current expiry time */
 734         hrtimer_add_expires_ns(&vcpu->arch.comparecount_timer,
 735                                vcpu->arch.count_period);
 736         return HRTIMER_RESTART;
 737 }
 738
 739 enum emulation_result kvm_mips_emul_eret(struct kvm_vcpu *vcpu)
 740 {
 741         struct mips_coproc *cop0 = vcpu->arch.cop0;
 742         enum emulation_result er = EMULATE_DONE;
 743
 744         if (kvm_read_c0_guest_status(cop0) & ST0_EXL) {
 745                 kvm_debug("[%#lx] ERET to %#lx\n", vcpu->arch.pc,
 746                           kvm_read_c0_guest_epc(cop0));
 747                 kvm_clear_c0_guest_status(cop0, ST0_EXL);
 748                 vcpu->arch.pc = kvm_read_c0_guest_epc(cop0);
 749
 750         } else if (kvm_read_c0_guest_status(cop0) & ST0_ERL) {
 751                 kvm_clear_c0_guest_status(cop0, ST0_ERL);
 752                 vcpu->arch.pc = kvm_read_c0_guest_errorepc(cop0);
 753         } else {
 754                 kvm_err("[%#lx] ERET when MIPS_SR_EXL|MIPS_SR_ERL == 0\n",
 755                         vcpu->arch.pc);
 756                 er = EMULATE_FAIL;
 757         }
 758
 759         return er;
 760 }
 761
 762 enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
 763 {
 764         kvm_debug("[%#lx] !!!WAIT!!! (%#lx)\n", vcpu->arch.pc,
 765                   vcpu->arch.pending_exceptions);
 766
 767         ++vcpu->stat.wait_exits;
 768         trace_kvm_exit(vcpu, WAIT_EXITS);
 769         if (!vcpu->arch.pending_exceptions) {
 770                 vcpu->arch.wait = 1;
 771                 kvm_vcpu_block(vcpu);
 772
 773                 /*
 774                  * We we are runnable, then definitely go off to user space to
 775                  * check if any I/O interrupts are pending.
 776                  */
 777                 if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
 778                         clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
 779                         vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
 780                 }
 781         }
 782
 783         return EMULATE_DONE;
 784 }
 785
 786 /*
 787  * XXXKYMA: Linux doesn't seem to use TLBR, return EMULATE_FAIL for now so that
 788  * we can catch this, if things ever change
 789  */
 790 enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu)
 791 {
 792         struct mips_coproc *cop0 = vcpu->arch.cop0;
 793         uint32_t pc = vcpu->arch.pc;
 794
 795         kvm_err("[%#x] COP0_TLBR [%ld]\n", pc, kvm_read_c0_guest_index(cop0));
 796         return EMULATE_FAIL;
 797 }
 798
 799 /* Write Guest TLB Entry @ Index */
 800 enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu)
 801 {
 802         struct mips_coproc *cop0 = vcpu->arch.cop0;
 803         int index = kvm_read_c0_guest_index(cop0);
 804         struct kvm_mips_tlb *tlb = NULL;
 805         uint32_t pc = vcpu->arch.pc;
 806
 807         if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) {
 808                 kvm_debug("%s: illegal index: %d\n", __func__, index);
 809                 kvm_debug("[%#x] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
 810                           pc, index, kvm_read_c0_guest_entryhi(cop0),
 811                           kvm_read_c0_guest_entrylo0(cop0),
 812                           kvm_read_c0_guest_entrylo1(cop0),
 813                           kvm_read_c0_guest_pagemask(cop0));
 814                 index = (index & ~0x80000000) % KVM_MIPS_GUEST_TLB_SIZE;
 815         }
 816
 817         tlb = &vcpu->arch.guest_tlb[index];
 818         /*
 819          * Probe the shadow host TLB for the entry being overwritten, if one
 820          * matches, invalidate it
 821          */
 822         kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
 823
 824         tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
 825         tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
 826         tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0);
 827         tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0);
 828
 829         kvm_debug("[%#x] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
 830                   pc, index, kvm_read_c0_guest_entryhi(cop0),
 831                   kvm_read_c0_guest_entrylo0(cop0),
 832                   kvm_read_c0_guest_entrylo1(cop0),
 833                   kvm_read_c0_guest_pagemask(cop0));
 834
 835         return EMULATE_DONE;
 836 }
 837
 838 /* Write Guest TLB Entry @ Random Index */
 839 enum emulation_result kvm_mips_emul_tlbwr(struct kvm_vcpu *vcpu)
 840 {
 841         struct mips_coproc *cop0 = vcpu->arch.cop0;
 842         struct kvm_mips_tlb *tlb = NULL;
 843         uint32_t pc = vcpu->arch.pc;
 844         int index;
 845
 846         get_random_bytes(&index, sizeof(index));
 847         index &= (KVM_MIPS_GUEST_TLB_SIZE - 1);
 848
 849         tlb = &vcpu->arch.guest_tlb[index];
 850
 851         /*
 852          * Probe the shadow host TLB for the entry being overwritten, if one
 853          * matches, invalidate it
 854          */
 855         kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
 856
 857         tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
 858         tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
 859         tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0);
 860         tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0);
 861
 862         kvm_debug("[%#x] COP0_TLBWR[%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx)\n",
 863                   pc, index, kvm_read_c0_guest_entryhi(cop0),
 864                   kvm_read_c0_guest_entrylo0(cop0),
 865                   kvm_read_c0_guest_entrylo1(cop0));
 866
 867         return EMULATE_DONE;
 868 }
 869
 870 enum emulation_result kvm_mips_emul_tlbp(struct kvm_vcpu *vcpu)
 871 {
 872         struct mips_coproc *cop0 = vcpu->arch.cop0;
 873         long entryhi = kvm_read_c0_guest_entryhi(cop0);
 874         uint32_t pc = vcpu->arch.pc;
 875         int index = -1;
 876
 877         index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
 878
 879         kvm_write_c0_guest_index(cop0, index);
 880
 881         kvm_debug("[%#x] COP0_TLBP (entryhi: %#lx), index: %d\n", pc, entryhi,
 882                   index);
 883
 884         return EMULATE_DONE;
 885 }
 886
 887 /**
 888  * kvm_mips_config1_wrmask() - Find mask of writable bits in guest Config1
 889  * @vcpu:       Virtual CPU.
 890  *
 891  * Finds the mask of bits which are writable in the guest's Config1 CP0
 892  * register, by userland (currently read-only to the guest).
 893  */
 894 unsigned int kvm_mips_config1_wrmask(struct kvm_vcpu *vcpu)
 895 {
 896         unsigned int mask = 0;
 897
 898         /* Permit FPU to be present if FPU is supported */
 899         if (kvm_mips_guest_can_have_fpu(&vcpu->arch))
 900                 mask |= MIPS_CONF1_FP;
 901
 902         return mask;
 903 }
 904
 905 /**
 906  * kvm_mips_config3_wrmask() - Find mask of writable bits in guest Config3
 907  * @vcpu:       Virtual CPU.
 908  *
 909  * Finds the mask of bits which are writable in the guest's Config3 CP0
 910  * register, by userland (currently read-only to the guest).
 911  */
 912 unsigned int kvm_mips_config3_wrmask(struct kvm_vcpu *vcpu)
 913 {
 914         /* Config4 is optional */
 915         unsigned int mask = MIPS_CONF_M;
 916
 917         /* Permit MSA to be present if MSA is supported */
 918         if (kvm_mips_guest_can_have_msa(&vcpu->arch))
 919                 mask |= MIPS_CONF3_MSA;
 920
 921         return mask;
 922 }
 923
 924 /**
 925  * kvm_mips_config4_wrmask() - Find mask of writable bits in guest Config4
 926  * @vcpu:       Virtual CPU.
 927  *
 928  * Finds the mask of bits which are writable in the guest's Config4 CP0
 929  * register, by userland (currently read-only to the guest).
 930  */
 931 unsigned int kvm_mips_config4_wrmask(struct kvm_vcpu *vcpu)
 932 {
 933         /* Config5 is optional */
 934         return MIPS_CONF_M;
 935 }
 936
 937 /**
 938  * kvm_mips_config5_wrmask() - Find mask of writable bits in guest Config5
 939  * @vcpu:       Virtual CPU.
 940  *
 941  * Finds the mask of bits which are writable in the guest's Config5 CP0
 942  * register, by the guest itself.
 943  */
 944 unsigned int kvm_mips_config5_wrmask(struct kvm_vcpu *vcpu)
 945 {
 946         unsigned int mask = 0;
 947
 948         /* Permit MSAEn changes if MSA supported and enabled */
 949         if (kvm_mips_guest_has_msa(&vcpu->arch))
 950                 mask |= MIPS_CONF5_MSAEN;
 951
 952         /*
 953          * Permit guest FPU mode changes if FPU is enabled and the relevant
 954          * feature exists according to FIR register.
 955          */
 956         if (kvm_mips_guest_has_fpu(&vcpu->arch)) {
 957                 if (cpu_has_fre)
 958                         mask |= MIPS_CONF5_FRE;
 959                 /* We don't support UFR or UFE */
 960         }
 961
 962         return mask;
 963 }
 964
 965 enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc,
 966                                            uint32_t cause, struct kvm_run *run,
 967                                            struct kvm_vcpu *vcpu)
 968 {
 969         struct mips_coproc *cop0 = vcpu->arch.cop0;
 970         enum emulation_result er = EMULATE_DONE;
 971         int32_t rt, rd, copz, sel, co_bit, op;
 972         uint32_t pc = vcpu->arch.pc;
 973         unsigned long curr_pc;
 974
 975         /*
 976          * Update PC and hold onto current PC in case there is
 977          * an error and we want to rollback the PC
 978          */
 979         curr_pc = vcpu->arch.pc;
 980         er = update_pc(vcpu, cause);
 981         if (er == EMULATE_FAIL)
 982                 return er;
 983
 984         copz = (inst >> 21) & 0x1f;
 985         rt = (inst >> 16) & 0x1f;
 986         rd = (inst >> 11) & 0x1f;
 987         sel = inst & 0x7;
 988         co_bit = (inst >> 25) & 1;
 989
 990         if (co_bit) {
 991                 op = (inst) & 0xff;
 992
 993                 switch (op) {
 994                 case tlbr_op:   /*  Read indexed TLB entry  */
 995                         er = kvm_mips_emul_tlbr(vcpu);
 996                         break;
 997                 case tlbwi_op:  /*  Write indexed  */
 998                         er = kvm_mips_emul_tlbwi(vcpu);
 999                         break;
1000                 case tlbwr_op:  /*  Write random  */
1001                         er = kvm_mips_emul_tlbwr(vcpu);
1002                         break;
1003                 case tlbp_op:   /* TLB Probe */
1004                         er = kvm_mips_emul_tlbp(vcpu);
1005                         break;
1006                 case rfe_op:
1007                         kvm_err("!!!COP0_RFE!!!\n");
1008                         break;
1009                 case eret_op:
1010                         er = kvm_mips_emul_eret(vcpu);
1011                         goto dont_update_pc;
1012                         break;
1013                 case wait_op:
1014                         er = kvm_mips_emul_wait(vcpu);
1015                         break;
1016                 }
1017         } else {
1018                 switch (copz) {
1019                 case mfc_op:
1020 #ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
1021                         cop0->stat[rd][sel]++;
1022 #endif
1023                         /* Get reg */
1024                         if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
1025                                 vcpu->arch.gprs[rt] = kvm_mips_read_count(vcpu);
1026                         } else if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) {
1027                                 vcpu->arch.gprs[rt] = 0x0;
1028 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1029                                 kvm_mips_trans_mfc0(inst, opc, vcpu);
1030 #endif
1031                         } else {
1032                                 vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
1033
1034 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1035                                 kvm_mips_trans_mfc0(inst, opc, vcpu);
1036 #endif
1037                         }
1038
1039                         kvm_debug
1040                             ("[%#x] MFCz[%d][%d], vcpu->arch.gprs[%d]: %#lx\n",
1041                              pc, rd, sel, rt, vcpu->arch.gprs[rt]);
1042
1043                         break;
1044
1045                 case dmfc_op:
1046                         vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
1047                         break;
1048
1049                 case mtc_op:
1050 #ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
1051                         cop0->stat[rd][sel]++;
1052 #endif
1053                         if ((rd == MIPS_CP0_TLB_INDEX)
1054                             && (vcpu->arch.gprs[rt] >=
1055                                 KVM_MIPS_GUEST_TLB_SIZE)) {
1056                                 kvm_err("Invalid TLB Index: %ld",
1057                                         vcpu->arch.gprs[rt]);
1058                                 er = EMULATE_FAIL;
1059                                 break;
1060                         }
1061 #define C0_EBASE_CORE_MASK 0xff
1062                         if ((rd == MIPS_CP0_PRID) && (sel == 1)) {
1063                                 /* Preserve CORE number */
1064                                 kvm_change_c0_guest_ebase(cop0,
1065                                                           ~(C0_EBASE_CORE_MASK),
1066                                                           vcpu->arch.gprs[rt]);
1067                                 kvm_err("MTCz, cop0->reg[EBASE]: %#lx\n",
1068                                         kvm_read_c0_guest_ebase(cop0));
1069                         } else if (rd == MIPS_CP0_TLB_HI && sel == 0) {
1070                                 uint32_t nasid =
1071                                         vcpu->arch.gprs[rt] & ASID_MASK;
1072                                 if ((KSEGX(vcpu->arch.gprs[rt]) != CKSEG0) &&
1073                                     ((kvm_read_c0_guest_entryhi(cop0) &
1074                                       ASID_MASK) != nasid)) {
1075                                         kvm_debug("MTCz, change ASID from %#lx to %#lx\n",
1076                                                 kvm_read_c0_guest_entryhi(cop0)
1077                                                 & ASID_MASK,
1078                                                 vcpu->arch.gprs[rt]
1079                                                 & ASID_MASK);
1080
1081                                         /* Blow away the shadow host TLBs */
1082                                         kvm_mips_flush_host_tlb(1);
1083                                 }
1084                                 kvm_write_c0_guest_entryhi(cop0,
1085                                                            vcpu->arch.gprs[rt]);
1086                         }
1087                         /* Are we writing to COUNT */
1088                         else if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
1089                                 kvm_mips_write_count(vcpu, vcpu->arch.gprs[rt]);
1090                                 goto done;
1091                         } else if ((rd == MIPS_CP0_COMPARE) && (sel == 0)) {
1092                                 kvm_debug("[%#x] MTCz, COMPARE %#lx <- %#lx\n",
1093                                           pc, kvm_read_c0_guest_compare(cop0),
1094                                           vcpu->arch.gprs[rt]);
1095
1096                                 /* If we are writing to COMPARE */
1097                                 /* Clear pending timer interrupt, if any */
1098                                 kvm_mips_callbacks->dequeue_timer_int(vcpu);
1099                                 kvm_mips_write_compare(vcpu,
1100                                                        vcpu->arch.gprs[rt]);
1101                         } else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) {
1102                                 unsigned int old_val, val, change;
1103
1104                                 old_val = kvm_read_c0_guest_status(cop0);
1105                                 val = vcpu->arch.gprs[rt];
1106                                 change = val ^ old_val;
1107
1108                                 /* Make sure that the NMI bit is never set */
1109                                 val &= ~ST0_NMI;
1110
1111                                 /*
1112                                  * Don't allow CU1 or FR to be set unless FPU
1113                                  * capability enabled and exists in guest
1114                                  * configuration.
1115                                  */
1116                                 if (!kvm_mips_guest_has_fpu(&vcpu->arch))
1117                                         val &= ~(ST0_CU1 | ST0_FR);
1118
1119                                 /*
1120                                  * Also don't allow FR to be set if host doesn't
1121                                  * support it.
1122                                  */
1123                                 if (!(current_cpu_data.fpu_id & MIPS_FPIR_F64))
1124                                         val &= ~ST0_FR;
1125
1126
1127                                 /* Handle changes in FPU mode */
1128                                 preempt_disable();
1129
1130                                 /*
1131                                  * FPU and Vector register state is made
1132                                  * UNPREDICTABLE by a change of FR, so don't
1133                                  * even bother saving it.
1134                                  */
1135                                 if (change & ST0_FR)
1136                                         kvm_drop_fpu(vcpu);
1137
1138                                 /*
1139                                  * If MSA state is already live, it is undefined
1140                                  * how it interacts with FR=0 FPU state, and we
1141                                  * don't want to hit reserved instruction
1142                                  * exceptions trying to save the MSA state later
1143                                  * when CU=1 && FR=1, so play it safe and save
1144                                  * it first.
1145                                  */
1146                                 if (change & ST0_CU1 && !(val & ST0_FR) &&
1147                                     vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA)
1148                                         kvm_lose_fpu(vcpu);
1149
1150                                 /*
1151                                  * Propagate CU1 (FPU enable) changes
1152                                  * immediately if the FPU context is already
1153                                  * loaded. When disabling we leave the context
1154                                  * loaded so it can be quickly enabled again in
1155                                  * the near future.
1156                                  */
1157                                 if (change & ST0_CU1 &&
1158                                     vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)
1159                                         change_c0_status(ST0_CU1, val);
1160
1161                                 preempt_enable();
1162
1163                                 kvm_write_c0_guest_status(cop0, val);
1164
1165 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1166                                 /*
1167                                  * If FPU present, we need CU1/FR bits to take
1168                                  * effect fairly soon.
1169                                  */
1170                                 if (!kvm_mips_guest_has_fpu(&vcpu->arch))
1171                                         kvm_mips_trans_mtc0(inst, opc, vcpu);
1172 #endif
1173                         } else if ((rd == MIPS_CP0_CONFIG) && (sel == 5)) {
1174                                 unsigned int old_val, val, change, wrmask;
1175
1176                                 old_val = kvm_read_c0_guest_config5(cop0);
1177                                 val = vcpu->arch.gprs[rt];
1178
1179                                 /* Only a few bits are writable in Config5 */
1180                                 wrmask = kvm_mips_config5_wrmask(vcpu);
1181                                 change = (val ^ old_val) & wrmask;
1182                                 val = old_val ^ change;
1183
1184
1185                                 /* Handle changes in FPU/MSA modes */
1186                                 preempt_disable();
1187
1188                                 /*
1189                                  * Propagate FRE changes immediately if the FPU
1190                                  * context is already loaded.
1191                                  */
1192                                 if (change & MIPS_CONF5_FRE &&
1193                                     vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)
1194                                         change_c0_config5(MIPS_CONF5_FRE, val);
1195
1196                                 /*
1197                                  * Propagate MSAEn changes immediately if the
1198                                  * MSA context is already loaded. When disabling
1199                                  * we leave the context loaded so it can be
1200                                  * quickly enabled again in the near future.
1201                                  */
1202                                 if (change & MIPS_CONF5_MSAEN &&
1203                                     vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA)
1204                                         change_c0_config5(MIPS_CONF5_MSAEN,
1205                                                           val);
1206
1207                                 preempt_enable();
1208
1209                                 kvm_write_c0_guest_config5(cop0, val);
1210                         } else if ((rd == MIPS_CP0_CAUSE) && (sel == 0)) {
1211                                 uint32_t old_cause, new_cause;
1212
1213                                 old_cause = kvm_read_c0_guest_cause(cop0);
1214                                 new_cause = vcpu->arch.gprs[rt];
1215                                 /* Update R/W bits */
1216                                 kvm_change_c0_guest_cause(cop0, 0x08800300,
1217                                                           new_cause);
1218                                 /* DC bit enabling/disabling timer? */
1219                                 if ((old_cause ^ new_cause) & CAUSEF_DC) {
1220                                         if (new_cause & CAUSEF_DC)
1221                                                 kvm_mips_count_disable_cause(vcpu);
1222                                         else
1223                                                 kvm_mips_count_enable_cause(vcpu);
1224                                 }
1225                         } else {
1226                                 cop0->reg[rd][sel] = vcpu->arch.gprs[rt];
1227 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1228                                 kvm_mips_trans_mtc0(inst, opc, vcpu);
1229 #endif
1230                         }
1231
1232                         kvm_debug("[%#x] MTCz, cop0->reg[%d][%d]: %#lx\n", pc,
1233                                   rd, sel, cop0->reg[rd][sel]);
1234                         break;
1235
1236                 case dmtc_op:
1237                         kvm_err("!!!!!!![%#lx]dmtc_op: rt: %d, rd: %d, sel: %d!!!!!!\n",
1238                                 vcpu->arch.pc, rt, rd, sel);
1239                         er = EMULATE_FAIL;
1240                         break;
1241
1242                 case mfmc0_op:
1243 #ifdef KVM_MIPS_DEBUG_COP0_COUNTERS
1244                         cop0->stat[MIPS_CP0_STATUS][0]++;
1245 #endif
1246                         if (rt != 0)
1247                                 vcpu->arch.gprs[rt] =
1248                                     kvm_read_c0_guest_status(cop0);
1249                         /* EI */
1250                         if (inst & 0x20) {
1251                                 kvm_debug("[%#lx] mfmc0_op: EI\n",
1252                                           vcpu->arch.pc);
1253                                 kvm_set_c0_guest_status(cop0, ST0_IE);
1254                         } else {
1255                                 kvm_debug("[%#lx] mfmc0_op: DI\n",
1256                                           vcpu->arch.pc);
1257                                 kvm_clear_c0_guest_status(cop0, ST0_IE);
1258                         }
1259
1260                         break;
1261
1262                 case wrpgpr_op:
1263                         {
1264                                 uint32_t css =
1265                                     cop0->reg[MIPS_CP0_STATUS][2] & 0xf;
1266                                 uint32_t pss =
1267                                     (cop0->reg[MIPS_CP0_STATUS][2] >> 6) & 0xf;
1268                                 /*
1269                                  * We don't support any shadow register sets, so
1270                                  * SRSCtl[PSS] == SRSCtl[CSS] = 0
1271                                  */
1272                                 if (css || pss) {
1273                                         er = EMULATE_FAIL;
1274                                         break;
1275                                 }
1276                                 kvm_debug("WRPGPR[%d][%d] = %#lx\n", pss, rd,
1277                                           vcpu->arch.gprs[rt]);
1278                                 vcpu->arch.gprs[rd] = vcpu->arch.gprs[rt];
1279                         }
1280                         break;
1281                 default:
1282                         kvm_err("[%#lx]MachEmulateCP0: unsupported COP0, copz: 0x%x\n",
1283                                 vcpu->arch.pc, copz);
1284                         er = EMULATE_FAIL;
1285                         break;
1286                 }
1287         }
1288
1289 done:
1290         /* Rollback PC only if emulation was unsuccessful */
1291         if (er == EMULATE_FAIL)
1292                 vcpu->arch.pc = curr_pc;
1293
1294 dont_update_pc:
1295         /*
1296          * This is for special instructions whose emulation
1297          * updates the PC, so do not overwrite the PC under
1298          * any circumstances
1299          */
1300
1301         return er;
1302 }
1303
1304 enum emulation_result kvm_mips_emulate_store(uint32_t inst, uint32_t cause,
1305                                              struct kvm_run *run,
1306                                              struct kvm_vcpu *vcpu)
1307 {
1308         enum emulation_result er = EMULATE_DO_MMIO;
1309         int32_t op, base, rt, offset;
1310         uint32_t bytes;
1311         void *data = run->mmio.data;
1312         unsigned long curr_pc;
1313
1314         /*
1315          * Update PC and hold onto current PC in case there is
1316          * an error and we want to rollback the PC
1317          */
1318         curr_pc = vcpu->arch.pc;
1319         er = update_pc(vcpu, cause);
1320         if (er == EMULATE_FAIL)
1321                 return er;
1322
1323         rt = (inst >> 16) & 0x1f;
1324         base = (inst >> 21) & 0x1f;
1325         offset = inst & 0xffff;
1326         op = (inst >> 26) & 0x3f;
1327
1328         switch (op) {
1329         case sb_op:
1330                 bytes = 1;
1331                 if (bytes > sizeof(run->mmio.data)) {
1332                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1333                                run->mmio.len);
1334                 }
1335                 run->mmio.phys_addr =
1336                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1337                                                    host_cp0_badvaddr);
1338                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1339                         er = EMULATE_FAIL;
1340                         break;
1341                 }
1342                 run->mmio.len = bytes;
1343                 run->mmio.is_write = 1;
1344                 vcpu->mmio_needed = 1;
1345                 vcpu->mmio_is_write = 1;
1346                 *(u8 *) data = vcpu->arch.gprs[rt];
1347                 kvm_debug("OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1348                           vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt],
1349                           *(uint8_t *) data);
1350
1351                 break;
1352
1353         case sw_op:
1354                 bytes = 4;
1355                 if (bytes > sizeof(run->mmio.data)) {
1356                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1357                                run->mmio.len);
1358                 }
1359                 run->mmio.phys_addr =
1360                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1361                                                    host_cp0_badvaddr);
1362                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1363                         er = EMULATE_FAIL;
1364                         break;
1365                 }
1366
1367                 run->mmio.len = bytes;
1368                 run->mmio.is_write = 1;
1369                 vcpu->mmio_needed = 1;
1370                 vcpu->mmio_is_write = 1;
1371                 *(uint32_t *) data = vcpu->arch.gprs[rt];
1372
1373                 kvm_debug("[%#lx] OP_SW: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1374                           vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1375                           vcpu->arch.gprs[rt], *(uint32_t *) data);
1376                 break;
1377
1378         case sh_op:
1379                 bytes = 2;
1380                 if (bytes > sizeof(run->mmio.data)) {
1381                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1382                                run->mmio.len);
1383                 }
1384                 run->mmio.phys_addr =
1385                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1386                                                    host_cp0_badvaddr);
1387                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1388                         er = EMULATE_FAIL;
1389                         break;
1390                 }
1391
1392                 run->mmio.len = bytes;
1393                 run->mmio.is_write = 1;
1394                 vcpu->mmio_needed = 1;
1395                 vcpu->mmio_is_write = 1;
1396                 *(uint16_t *) data = vcpu->arch.gprs[rt];
1397
1398                 kvm_debug("[%#lx] OP_SH: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1399                           vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1400                           vcpu->arch.gprs[rt], *(uint32_t *) data);
1401                 break;
1402
1403         default:
1404                 kvm_err("Store not yet supported");
1405                 er = EMULATE_FAIL;
1406                 break;
1407         }
1408
1409         /* Rollback PC if emulation was unsuccessful */
1410         if (er == EMULATE_FAIL)
1411                 vcpu->arch.pc = curr_pc;
1412
1413         return er;
1414 }
1415
1416 enum emulation_result kvm_mips_emulate_load(uint32_t inst, uint32_t cause,
1417                                             struct kvm_run *run,
1418                                             struct kvm_vcpu *vcpu)
1419 {
1420         enum emulation_result er = EMULATE_DO_MMIO;
1421         int32_t op, base, rt, offset;
1422         uint32_t bytes;
1423
1424         rt = (inst >> 16) & 0x1f;
1425         base = (inst >> 21) & 0x1f;
1426         offset = inst & 0xffff;
1427         op = (inst >> 26) & 0x3f;
1428
1429         vcpu->arch.pending_load_cause = cause;
1430         vcpu->arch.io_gpr = rt;
1431
1432         switch (op) {
1433         case lw_op:
1434                 bytes = 4;
1435                 if (bytes > sizeof(run->mmio.data)) {
1436                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1437                                run->mmio.len);
1438                         er = EMULATE_FAIL;
1439                         break;
1440                 }
1441                 run->mmio.phys_addr =
1442                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1443                                                    host_cp0_badvaddr);
1444                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1445                         er = EMULATE_FAIL;
1446                         break;
1447                 }
1448
1449                 run->mmio.len = bytes;
1450                 run->mmio.is_write = 0;
1451                 vcpu->mmio_needed = 1;
1452                 vcpu->mmio_is_write = 0;
1453                 break;
1454
1455         case lh_op:
1456         case lhu_op:
1457                 bytes = 2;
1458                 if (bytes > sizeof(run->mmio.data)) {
1459                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1460                                run->mmio.len);
1461                         er = EMULATE_FAIL;
1462                         break;
1463                 }
1464                 run->mmio.phys_addr =
1465                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1466                                                    host_cp0_badvaddr);
1467                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1468                         er = EMULATE_FAIL;
1469                         break;
1470                 }
1471
1472                 run->mmio.len = bytes;
1473                 run->mmio.is_write = 0;
1474                 vcpu->mmio_needed = 1;
1475                 vcpu->mmio_is_write = 0;
1476
1477                 if (op == lh_op)
1478                         vcpu->mmio_needed = 2;
1479                 else
1480                         vcpu->mmio_needed = 1;
1481
1482                 break;
1483
1484         case lbu_op:
1485         case lb_op:
1486                 bytes = 1;
1487                 if (bytes > sizeof(run->mmio.data)) {
1488                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1489                                run->mmio.len);
1490                         er = EMULATE_FAIL;
1491                         break;
1492                 }
1493                 run->mmio.phys_addr =
1494                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1495                                                    host_cp0_badvaddr);
1496                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1497                         er = EMULATE_FAIL;
1498                         break;
1499                 }
1500
1501                 run->mmio.len = bytes;
1502                 run->mmio.is_write = 0;
1503                 vcpu->mmio_is_write = 0;
1504
1505                 if (op == lb_op)
1506                         vcpu->mmio_needed = 2;
1507                 else
1508                         vcpu->mmio_needed = 1;
1509
1510                 break;
1511
1512         default:
1513                 kvm_err("Load not yet supported");
1514                 er = EMULATE_FAIL;
1515                 break;
1516         }
1517
1518         return er;
1519 }
1520
1521 int kvm_mips_sync_icache(unsigned long va, struct kvm_vcpu *vcpu)
1522 {
1523         unsigned long offset = (va & ~PAGE_MASK);
1524         struct kvm *kvm = vcpu->kvm;
1525         unsigned long pa;
1526         gfn_t gfn;
1527         kvm_pfn_t pfn;
1528
1529         gfn = va >> PAGE_SHIFT;
1530
1531         if (gfn >= kvm->arch.guest_pmap_npages) {
1532                 kvm_err("%s: Invalid gfn: %#llx\n", __func__, gfn);
1533                 kvm_mips_dump_host_tlbs();
1534                 kvm_arch_vcpu_dump_regs(vcpu);
1535                 return -1;
1536         }
1537         pfn = kvm->arch.guest_pmap[gfn];
1538         pa = (pfn << PAGE_SHIFT) | offset;
1539
1540         kvm_debug("%s: va: %#lx, unmapped: %#x\n", __func__, va,
1541                   CKSEG0ADDR(pa));
1542
1543         local_flush_icache_range(CKSEG0ADDR(pa), 32);
1544         return 0;
1545 }
1546
1547 enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc,
1548                                              uint32_t cause,
1549                                              struct kvm_run *run,
1550                                              struct kvm_vcpu *vcpu)
1551 {
1552         struct mips_coproc *cop0 = vcpu->arch.cop0;
1553         enum emulation_result er = EMULATE_DONE;
1554         int32_t offset, cache, op_inst, op, base;
1555         struct kvm_vcpu_arch *arch = &vcpu->arch;
1556         unsigned long va;
1557         unsigned long curr_pc;
1558
1559         /*
1560          * Update PC and hold onto current PC in case there is
1561          * an error and we want to rollback the PC
1562          */
1563         curr_pc = vcpu->arch.pc;
1564         er = update_pc(vcpu, cause);
1565         if (er == EMULATE_FAIL)
1566                 return er;
1567
1568         base = (inst >> 21) & 0x1f;
1569         op_inst = (inst >> 16) & 0x1f;
1570         offset = (int16_t)inst;
1571         cache = op_inst & CacheOp_Cache;
1572         op = op_inst & CacheOp_Op;
1573
1574         va = arch->gprs[base] + offset;
1575
1576         kvm_debug("CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1577                   cache, op, base, arch->gprs[base], offset);
1578
1579         /*
1580          * Treat INDEX_INV as a nop, basically issued by Linux on startup to
1581          * invalidate the caches entirely by stepping through all the
1582          * ways/indexes
1583          */
1584         if (op == Index_Writeback_Inv) {
1585                 kvm_debug("@ %#lx/%#lx CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1586                           vcpu->arch.pc, vcpu->arch.gprs[31], cache, op, base,
1587                           arch->gprs[base], offset);
1588
1589                 if (cache == Cache_D)
1590                         r4k_blast_dcache();
1591                 else if (cache == Cache_I)
1592                         r4k_blast_icache();
1593                 else {
1594                         kvm_err("%s: unsupported CACHE INDEX operation\n",
1595                                 __func__);
1596                         return EMULATE_FAIL;
1597                 }
1598
1599 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1600                 kvm_mips_trans_cache_index(inst, opc, vcpu);
1601 #endif
1602                 goto done;
1603         }
1604
1605         preempt_disable();
1606         if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
1607                 if (kvm_mips_host_tlb_lookup(vcpu, va) < 0)
1608                         kvm_mips_handle_kseg0_tlb_fault(va, vcpu);
1609         } else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) ||
1610                    KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
1611                 int index;
1612
1613                 /* If an entry already exists then skip */
1614                 if (kvm_mips_host_tlb_lookup(vcpu, va) >= 0)
1615                         goto skip_fault;
1616
1617                 /*
1618                  * If address not in the guest TLB, then give the guest a fault,
1619                  * the resulting handler will do the right thing
1620                  */
1621                 index = kvm_mips_guest_tlb_lookup(vcpu, (va & VPN2_MASK) |
1622                                                   (kvm_read_c0_guest_entryhi
1623                                                    (cop0) & ASID_MASK));
1624
1625                 if (index < 0) {
1626                         vcpu->arch.host_cp0_entryhi = (va & VPN2_MASK);
1627                         vcpu->arch.host_cp0_badvaddr = va;
1628                         er = kvm_mips_emulate_tlbmiss_ld(cause, NULL, run,
1629                                                          vcpu);
1630                         preempt_enable();
1631                         goto dont_update_pc;
1632                 } else {
1633                         struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
1634                         /*
1635                          * Check if the entry is valid, if not then setup a TLB
1636                          * invalid exception to the guest
1637                          */
1638                         if (!TLB_IS_VALID(*tlb, va)) {
1639                                 er = kvm_mips_emulate_tlbinv_ld(cause, NULL,
1640                                                                 run, vcpu);
1641                                 preempt_enable();
1642                                 goto dont_update_pc;
1643                         } else {
1644                                 /*
1645                                  * We fault an entry from the guest tlb to the
1646                                  * shadow host TLB
1647                                  */
1648                                 kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
1649                                                                      NULL,
1650                                                                      NULL);
1651                         }
1652                 }
1653         } else {
1654                 kvm_err("INVALID CACHE INDEX/ADDRESS (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1655                         cache, op, base, arch->gprs[base], offset);
1656                 er = EMULATE_FAIL;
1657                 preempt_enable();
1658                 goto dont_update_pc;
1659
1660         }
1661
1662 skip_fault:
1663         /* XXXKYMA: Only a subset of cache ops are supported, used by Linux */
1664         if (op_inst == Hit_Writeback_Inv_D || op_inst == Hit_Invalidate_D) {
1665                 flush_dcache_line(va);
1666
1667 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1668                 /*
1669                  * Replace the CACHE instruction, with a SYNCI, not the same,
1670                  * but avoids a trap
1671                  */
1672                 kvm_mips_trans_cache_va(inst, opc, vcpu);
1673 #endif
1674         } else if (op_inst == Hit_Invalidate_I) {
1675                 flush_dcache_line(va);
1676                 flush_icache_line(va);
1677
1678 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1679                 /* Replace the CACHE instruction, with a SYNCI */
1680                 kvm_mips_trans_cache_va(inst, opc, vcpu);
1681 #endif
1682         } else {
1683                 kvm_err("NO-OP CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1684                         cache, op, base, arch->gprs[base], offset);
1685                 er = EMULATE_FAIL;
1686                 preempt_enable();
1687                 goto dont_update_pc;
1688         }
1689
1690         preempt_enable();
1691
1692 dont_update_pc:
1693         /* Rollback PC */
1694         vcpu->arch.pc = curr_pc;
1695 done:
1696         return er;
1697 }
1698
1699 enum emulation_result kvm_mips_emulate_inst(unsigned long cause, uint32_t *opc,
1700                                             struct kvm_run *run,
1701                                             struct kvm_vcpu *vcpu)
1702 {
1703         enum emulation_result er = EMULATE_DONE;
1704         uint32_t inst;
1705
1706         /* Fetch the instruction. */
1707         if (cause & CAUSEF_BD)
1708                 opc += 1;
1709
1710         inst = kvm_get_inst(opc, vcpu);
1711
1712         switch (((union mips_instruction)inst).r_format.opcode) {
1713         case cop0_op:
1714                 er = kvm_mips_emulate_CP0(inst, opc, cause, run, vcpu);
1715                 break;
1716         case sb_op:
1717         case sh_op:
1718         case sw_op:
1719                 er = kvm_mips_emulate_store(inst, cause, run, vcpu);
1720                 break;
1721         case lb_op:
1722         case lbu_op:
1723         case lhu_op:
1724         case lh_op:
1725         case lw_op:
1726                 er = kvm_mips_emulate_load(inst, cause, run, vcpu);
1727                 break;
1728
1729         case cache_op:
1730                 ++vcpu->stat.cache_exits;
1731                 trace_kvm_exit(vcpu, CACHE_EXITS);
1732                 er = kvm_mips_emulate_cache(inst, opc, cause, run, vcpu);
1733                 break;
1734
1735         default:
1736                 kvm_err("Instruction emulation not supported (%p/%#x)\n", opc,
1737                         inst);
1738                 kvm_arch_vcpu_dump_regs(vcpu);
1739                 er = EMULATE_FAIL;
1740                 break;
1741         }
1742
1743         return er;
1744 }
1745
1746 enum emulation_result kvm_mips_emulate_syscall(unsigned long cause,
1747                                                uint32_t *opc,
1748                                                struct kvm_run *run,
1749                                                struct kvm_vcpu *vcpu)
1750 {
1751         struct mips_coproc *cop0 = vcpu->arch.cop0;
1752         struct kvm_vcpu_arch *arch = &vcpu->arch;
1753         enum emulation_result er = EMULATE_DONE;
1754
1755         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1756                 /* save old pc */
1757                 kvm_write_c0_guest_epc(cop0, arch->pc);
1758                 kvm_set_c0_guest_status(cop0, ST0_EXL);
1759
1760                 if (cause & CAUSEF_BD)
1761                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1762                 else
1763                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1764
1765                 kvm_debug("Delivering SYSCALL @ pc %#lx\n", arch->pc);
1766
1767                 kvm_change_c0_guest_cause(cop0, (0xff),
1768                                           (EXCCODE_SYS << CAUSEB_EXCCODE));
1769
1770                 /* Set PC to the exception entry point */
1771                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1772
1773         } else {
1774                 kvm_err("Trying to deliver SYSCALL when EXL is already set\n");
1775                 er = EMULATE_FAIL;
1776         }
1777
1778         return er;
1779 }
1780
1781 enum emulation_result kvm_mips_emulate_tlbmiss_ld(unsigned long cause,
1782                                                   uint32_t *opc,
1783                                                   struct kvm_run *run,
1784                                                   struct kvm_vcpu *vcpu)
1785 {
1786         struct mips_coproc *cop0 = vcpu->arch.cop0;
1787         struct kvm_vcpu_arch *arch = &vcpu->arch;
1788         unsigned long entryhi = (vcpu->arch.  host_cp0_badvaddr & VPN2_MASK) |
1789                                 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1790
1791         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1792                 /* save old pc */
1793                 kvm_write_c0_guest_epc(cop0, arch->pc);
1794                 kvm_set_c0_guest_status(cop0, ST0_EXL);
1795
1796                 if (cause & CAUSEF_BD)
1797                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1798                 else
1799                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1800
1801                 kvm_debug("[EXL == 0] delivering TLB MISS @ pc %#lx\n",
1802                           arch->pc);
1803
1804                 /* set pc to the exception entry point */
1805                 arch->pc = KVM_GUEST_KSEG0 + 0x0;
1806
1807         } else {
1808                 kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1809                           arch->pc);
1810
1811                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1812         }
1813
1814         kvm_change_c0_guest_cause(cop0, (0xff),
1815                                   (EXCCODE_TLBL << CAUSEB_EXCCODE));
1816
1817         /* setup badvaddr, context and entryhi registers for the guest */
1818         kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1819         /* XXXKYMA: is the context register used by linux??? */
1820         kvm_write_c0_guest_entryhi(cop0, entryhi);
1821         /* Blow away the shadow host TLBs */
1822         kvm_mips_flush_host_tlb(1);
1823
1824         return EMULATE_DONE;
1825 }
1826
1827 enum emulation_result kvm_mips_emulate_tlbinv_ld(unsigned long cause,
1828                                                  uint32_t *opc,
1829                                                  struct kvm_run *run,
1830                                                  struct kvm_vcpu *vcpu)
1831 {
1832         struct mips_coproc *cop0 = vcpu->arch.cop0;
1833         struct kvm_vcpu_arch *arch = &vcpu->arch;
1834         unsigned long entryhi =
1835                 (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1836                 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1837
1838         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1839                 /* save old pc */
1840                 kvm_write_c0_guest_epc(cop0, arch->pc);
1841                 kvm_set_c0_guest_status(cop0, ST0_EXL);
1842
1843                 if (cause & CAUSEF_BD)
1844                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1845                 else
1846                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1847
1848                 kvm_debug("[EXL == 0] delivering TLB INV @ pc %#lx\n",
1849                           arch->pc);
1850
1851                 /* set pc to the exception entry point */
1852                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1853
1854         } else {
1855                 kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1856                           arch->pc);
1857                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1858         }
1859
1860         kvm_change_c0_guest_cause(cop0, (0xff),
1861                                   (EXCCODE_TLBL << CAUSEB_EXCCODE));
1862
1863         /* setup badvaddr, context and entryhi registers for the guest */
1864         kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1865         /* XXXKYMA: is the context register used by linux??? */
1866         kvm_write_c0_guest_entryhi(cop0, entryhi);
1867         /* Blow away the shadow host TLBs */
1868         kvm_mips_flush_host_tlb(1);
1869
1870         return EMULATE_DONE;
1871 }
1872
1873 enum emulation_result kvm_mips_emulate_tlbmiss_st(unsigned long cause,
1874                                                   uint32_t *opc,
1875                                                   struct kvm_run *run,
1876                                                   struct kvm_vcpu *vcpu)
1877 {
1878         struct mips_coproc *cop0 = vcpu->arch.cop0;
1879         struct kvm_vcpu_arch *arch = &vcpu->arch;
1880         unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1881                                 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1882
1883         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1884                 /* save old pc */
1885                 kvm_write_c0_guest_epc(cop0, arch->pc);
1886                 kvm_set_c0_guest_status(cop0, ST0_EXL);
1887
1888                 if (cause & CAUSEF_BD)
1889                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1890                 else
1891                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1892
1893                 kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
1894                           arch->pc);
1895
1896                 /* Set PC to the exception entry point */
1897                 arch->pc = KVM_GUEST_KSEG0 + 0x0;
1898         } else {
1899                 kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
1900                           arch->pc);
1901                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1902         }
1903
1904         kvm_change_c0_guest_cause(cop0, (0xff),
1905                                   (EXCCODE_TLBS << CAUSEB_EXCCODE));
1906
1907         /* setup badvaddr, context and entryhi registers for the guest */
1908         kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1909         /* XXXKYMA: is the context register used by linux??? */
1910         kvm_write_c0_guest_entryhi(cop0, entryhi);
1911         /* Blow away the shadow host TLBs */
1912         kvm_mips_flush_host_tlb(1);
1913
1914         return EMULATE_DONE;
1915 }
1916
1917 enum emulation_result kvm_mips_emulate_tlbinv_st(unsigned long cause,
1918                                                  uint32_t *opc,
1919                                                  struct kvm_run *run,
1920                                                  struct kvm_vcpu *vcpu)
1921 {
1922         struct mips_coproc *cop0 = vcpu->arch.cop0;
1923         struct kvm_vcpu_arch *arch = &vcpu->arch;
1924         unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1925                 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1926
1927         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1928                 /* save old pc */
1929                 kvm_write_c0_guest_epc(cop0, arch->pc);
1930                 kvm_set_c0_guest_status(cop0, ST0_EXL);
1931
1932                 if (cause & CAUSEF_BD)
1933                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1934                 else
1935                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1936
1937                 kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
1938                           arch->pc);
1939
1940                 /* Set PC to the exception entry point */
1941                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1942         } else {
1943                 kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
1944                           arch->pc);
1945                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1946         }
1947
1948         kvm_change_c0_guest_cause(cop0, (0xff),
1949                                   (EXCCODE_TLBS << CAUSEB_EXCCODE));
1950
1951         /* setup badvaddr, context and entryhi registers for the guest */
1952         kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1953         /* XXXKYMA: is the context register used by linux??? */
1954         kvm_write_c0_guest_entryhi(cop0, entryhi);
1955         /* Blow away the shadow host TLBs */
1956         kvm_mips_flush_host_tlb(1);
1957
1958         return EMULATE_DONE;
1959 }
1960
1961 /* TLBMOD: store into address matching TLB with Dirty bit off */
1962 enum emulation_result kvm_mips_handle_tlbmod(unsigned long cause, uint32_t *opc,
1963                                              struct kvm_run *run,
1964                                              struct kvm_vcpu *vcpu)
1965 {
1966         enum emulation_result er = EMULATE_DONE;
1967 #ifdef DEBUG
1968         struct mips_coproc *cop0 = vcpu->arch.cop0;
1969         unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1970                                 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1971         int index;
1972
1973         /* If address not in the guest TLB, then we are in trouble */
1974         index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
1975         if (index < 0) {
1976                 /* XXXKYMA Invalidate and retry */
1977                 kvm_mips_host_tlb_inv(vcpu, vcpu->arch.host_cp0_badvaddr);
1978                 kvm_err("%s: host got TLBMOD for %#lx but entry not present in Guest TLB\n",
1979                      __func__, entryhi);
1980                 kvm_mips_dump_guest_tlbs(vcpu);
1981                 kvm_mips_dump_host_tlbs();
1982                 return EMULATE_FAIL;
1983         }
1984 #endif
1985
1986         er = kvm_mips_emulate_tlbmod(cause, opc, run, vcpu);
1987         return er;
1988 }
1989
1990 enum emulation_result kvm_mips_emulate_tlbmod(unsigned long cause,
1991                                               uint32_t *opc,
1992                                               struct kvm_run *run,
1993                                               struct kvm_vcpu *vcpu)
1994 {
1995         struct mips_coproc *cop0 = vcpu->arch.cop0;
1996         unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1997                                 (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1998         struct kvm_vcpu_arch *arch = &vcpu->arch;
1999
2000         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2001                 /* save old pc */
2002                 kvm_write_c0_guest_epc(cop0, arch->pc);
2003                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2004
2005                 if (cause & CAUSEF_BD)
2006                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2007                 else
2008                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2009
2010                 kvm_debug("[EXL == 0] Delivering TLB MOD @ pc %#lx\n",
2011                           arch->pc);
2012
2013                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2014         } else {
2015                 kvm_debug("[EXL == 1] Delivering TLB MOD @ pc %#lx\n",
2016                           arch->pc);
2017                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2018         }
2019
2020         kvm_change_c0_guest_cause(cop0, (0xff),
2021                                   (EXCCODE_MOD << CAUSEB_EXCCODE));
2022
2023         /* setup badvaddr, context and entryhi registers for the guest */
2024         kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2025         /* XXXKYMA: is the context register used by linux??? */
2026         kvm_write_c0_guest_entryhi(cop0, entryhi);
2027         /* Blow away the shadow host TLBs */
2028         kvm_mips_flush_host_tlb(1);
2029
2030         return EMULATE_DONE;
2031 }
2032
2033 enum emulation_result kvm_mips_emulate_fpu_exc(unsigned long cause,
2034                                                uint32_t *opc,
2035                                                struct kvm_run *run,
2036                                                struct kvm_vcpu *vcpu)
2037 {
2038         struct mips_coproc *cop0 = vcpu->arch.cop0;
2039         struct kvm_vcpu_arch *arch = &vcpu->arch;
2040
2041         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2042                 /* save old pc */
2043                 kvm_write_c0_guest_epc(cop0, arch->pc);
2044                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2045
2046                 if (cause & CAUSEF_BD)
2047                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2048                 else
2049                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2050
2051         }
2052
2053         arch->pc = KVM_GUEST_KSEG0 + 0x180;
2054
2055         kvm_change_c0_guest_cause(cop0, (0xff),
2056                                   (EXCCODE_CPU << CAUSEB_EXCCODE));
2057         kvm_change_c0_guest_cause(cop0, (CAUSEF_CE), (0x1 << CAUSEB_CE));
2058
2059         return EMULATE_DONE;
2060 }
2061
2062 enum emulation_result kvm_mips_emulate_ri_exc(unsigned long cause,
2063                                               uint32_t *opc,
2064                                               struct kvm_run *run,
2065                                               struct kvm_vcpu *vcpu)
2066 {
2067         struct mips_coproc *cop0 = vcpu->arch.cop0;
2068         struct kvm_vcpu_arch *arch = &vcpu->arch;
2069         enum emulation_result er = EMULATE_DONE;
2070
2071         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2072                 /* save old pc */
2073                 kvm_write_c0_guest_epc(cop0, arch->pc);
2074                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2075
2076                 if (cause & CAUSEF_BD)
2077                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2078                 else
2079                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2080
2081                 kvm_debug("Delivering RI @ pc %#lx\n", arch->pc);
2082
2083                 kvm_change_c0_guest_cause(cop0, (0xff),
2084                                           (EXCCODE_RI << CAUSEB_EXCCODE));
2085
2086                 /* Set PC to the exception entry point */
2087                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2088
2089         } else {
2090                 kvm_err("Trying to deliver RI when EXL is already set\n");
2091                 er = EMULATE_FAIL;
2092         }
2093
2094         return er;
2095 }
2096
2097 enum emulation_result kvm_mips_emulate_bp_exc(unsigned long cause,
2098                                               uint32_t *opc,
2099                                               struct kvm_run *run,
2100                                               struct kvm_vcpu *vcpu)
2101 {
2102         struct mips_coproc *cop0 = vcpu->arch.cop0;
2103         struct kvm_vcpu_arch *arch = &vcpu->arch;
2104         enum emulation_result er = EMULATE_DONE;
2105
2106         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2107                 /* save old pc */
2108                 kvm_write_c0_guest_epc(cop0, arch->pc);
2109                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2110
2111                 if (cause & CAUSEF_BD)
2112                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2113                 else
2114                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2115
2116                 kvm_debug("Delivering BP @ pc %#lx\n", arch->pc);
2117
2118                 kvm_change_c0_guest_cause(cop0, (0xff),
2119                                           (EXCCODE_BP << CAUSEB_EXCCODE));
2120
2121                 /* Set PC to the exception entry point */
2122                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2123
2124         } else {
2125                 kvm_err("Trying to deliver BP when EXL is already set\n");
2126                 er = EMULATE_FAIL;
2127         }
2128
2129         return er;
2130 }
2131
2132 enum emulation_result kvm_mips_emulate_trap_exc(unsigned long cause,
2133                                                 uint32_t *opc,
2134                                                 struct kvm_run *run,
2135                                                 struct kvm_vcpu *vcpu)
2136 {
2137         struct mips_coproc *cop0 = vcpu->arch.cop0;
2138         struct kvm_vcpu_arch *arch = &vcpu->arch;
2139         enum emulation_result er = EMULATE_DONE;
2140
2141         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2142                 /* save old pc */
2143                 kvm_write_c0_guest_epc(cop0, arch->pc);
2144                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2145
2146                 if (cause & CAUSEF_BD)
2147                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2148                 else
2149                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2150
2151                 kvm_debug("Delivering TRAP @ pc %#lx\n", arch->pc);
2152
2153                 kvm_change_c0_guest_cause(cop0, (0xff),
2154                                           (EXCCODE_TR << CAUSEB_EXCCODE));
2155
2156                 /* Set PC to the exception entry point */
2157                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2158
2159         } else {
2160                 kvm_err("Trying to deliver TRAP when EXL is already set\n");
2161                 er = EMULATE_FAIL;
2162         }
2163
2164         return er;
2165 }
2166
2167 enum emulation_result kvm_mips_emulate_msafpe_exc(unsigned long cause,
2168                                                   uint32_t *opc,
2169                                                   struct kvm_run *run,
2170                                                   struct kvm_vcpu *vcpu)
2171 {
2172         struct mips_coproc *cop0 = vcpu->arch.cop0;
2173         struct kvm_vcpu_arch *arch = &vcpu->arch;
2174         enum emulation_result er = EMULATE_DONE;
2175
2176         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2177                 /* save old pc */
2178                 kvm_write_c0_guest_epc(cop0, arch->pc);
2179                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2180
2181                 if (cause & CAUSEF_BD)
2182                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2183                 else
2184                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2185
2186                 kvm_debug("Delivering MSAFPE @ pc %#lx\n", arch->pc);
2187
2188                 kvm_change_c0_guest_cause(cop0, (0xff),
2189                                           (EXCCODE_MSAFPE << CAUSEB_EXCCODE));
2190
2191                 /* Set PC to the exception entry point */
2192                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2193
2194         } else {
2195                 kvm_err("Trying to deliver MSAFPE when EXL is already set\n");
2196                 er = EMULATE_FAIL;
2197         }
2198
2199         return er;
2200 }
2201
2202 enum emulation_result kvm_mips_emulate_fpe_exc(unsigned long cause,
2203                                                uint32_t *opc,
2204                                                struct kvm_run *run,
2205                                                struct kvm_vcpu *vcpu)
2206 {
2207         struct mips_coproc *cop0 = vcpu->arch.cop0;
2208         struct kvm_vcpu_arch *arch = &vcpu->arch;
2209         enum emulation_result er = EMULATE_DONE;
2210
2211         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2212                 /* save old pc */
2213                 kvm_write_c0_guest_epc(cop0, arch->pc);
2214                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2215
2216                 if (cause & CAUSEF_BD)
2217                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2218                 else
2219                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2220
2221                 kvm_debug("Delivering FPE @ pc %#lx\n", arch->pc);
2222
2223                 kvm_change_c0_guest_cause(cop0, (0xff),
2224                                           (EXCCODE_FPE << CAUSEB_EXCCODE));
2225
2226                 /* Set PC to the exception entry point */
2227                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2228
2229         } else {
2230                 kvm_err("Trying to deliver FPE when EXL is already set\n");
2231                 er = EMULATE_FAIL;
2232         }
2233
2234         return er;
2235 }
2236
2237 enum emulation_result kvm_mips_emulate_msadis_exc(unsigned long cause,
2238                                                   uint32_t *opc,
2239                                                   struct kvm_run *run,
2240                                                   struct kvm_vcpu *vcpu)
2241 {
2242         struct mips_coproc *cop0 = vcpu->arch.cop0;
2243         struct kvm_vcpu_arch *arch = &vcpu->arch;
2244         enum emulation_result er = EMULATE_DONE;
2245
2246         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2247                 /* save old pc */
2248                 kvm_write_c0_guest_epc(cop0, arch->pc);
2249                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2250
2251                 if (cause & CAUSEF_BD)
2252                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2253                 else
2254                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2255
2256                 kvm_debug("Delivering MSADIS @ pc %#lx\n", arch->pc);
2257
2258                 kvm_change_c0_guest_cause(cop0, (0xff),
2259                                           (EXCCODE_MSADIS << CAUSEB_EXCCODE));
2260
2261                 /* Set PC to the exception entry point */
2262                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2263
2264         } else {
2265                 kvm_err("Trying to deliver MSADIS when EXL is already set\n");
2266                 er = EMULATE_FAIL;
2267         }
2268
2269         return er;
2270 }
2271
2272 /* ll/sc, rdhwr, sync emulation */
2273
2274 #define OPCODE 0xfc000000
2275 #define BASE   0x03e00000
2276 #define RT     0x001f0000
2277 #define OFFSET 0x0000ffff
2278 #define LL     0xc0000000
2279 #define SC     0xe0000000
2280 #define SPEC0  0x00000000
2281 #define SPEC3  0x7c000000
2282 #define RD     0x0000f800
2283 #define FUNC   0x0000003f
2284 #define SYNC   0x0000000f
2285 #define RDHWR  0x0000003b
2286
2287 enum emulation_result kvm_mips_handle_ri(unsigned long cause, uint32_t *opc,
2288                                          struct kvm_run *run,
2289                                          struct kvm_vcpu *vcpu)
2290 {
2291         struct mips_coproc *cop0 = vcpu->arch.cop0;
2292         struct kvm_vcpu_arch *arch = &vcpu->arch;
2293         enum emulation_result er = EMULATE_DONE;
2294         unsigned long curr_pc;
2295         uint32_t inst;
2296
2297         /*
2298          * Update PC and hold onto current PC in case there is
2299          * an error and we want to rollback the PC
2300          */
2301         curr_pc = vcpu->arch.pc;
2302         er = update_pc(vcpu, cause);
2303         if (er == EMULATE_FAIL)
2304                 return er;
2305
2306         /* Fetch the instruction. */
2307         if (cause & CAUSEF_BD)
2308                 opc += 1;
2309
2310         inst = kvm_get_inst(opc, vcpu);
2311
2312         if (inst == KVM_INVALID_INST) {
2313                 kvm_err("%s: Cannot get inst @ %p\n", __func__, opc);
2314                 return EMULATE_FAIL;
2315         }
2316
2317         if ((inst & OPCODE) == SPEC3 && (inst & FUNC) == RDHWR) {
2318                 int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
2319                 int rd = (inst & RD) >> 11;
2320                 int rt = (inst & RT) >> 16;
2321                 /* If usermode, check RDHWR rd is allowed by guest HWREna */
2322                 if (usermode && !(kvm_read_c0_guest_hwrena(cop0) & BIT(rd))) {
2323                         kvm_debug("RDHWR %#x disallowed by HWREna @ %p\n",
2324                                   rd, opc);
2325                         goto emulate_ri;
2326                 }
2327                 switch (rd) {
2328                 case 0: /* CPU number */
2329                         arch->gprs[rt] = 0;
2330                         break;
2331                 case 1: /* SYNCI length */
2332                         arch->gprs[rt] = min(current_cpu_data.dcache.linesz,
2333                                              current_cpu_data.icache.linesz);
2334                         break;
2335                 case 2: /* Read count register */
2336                         arch->gprs[rt] = kvm_mips_read_count(vcpu);
2337                         break;
2338                 case 3: /* Count register resolution */
2339                         switch (current_cpu_data.cputype) {
2340                         case CPU_20KC:
2341                         case CPU_25KF:
2342                                 arch->gprs[rt] = 1;
2343                                 break;
2344                         default:
2345                                 arch->gprs[rt] = 2;
2346                         }
2347                         break;
2348                 case 29:
2349                         arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0);
2350                         break;
2351
2352                 default:
2353                         kvm_debug("RDHWR %#x not supported @ %p\n", rd, opc);
2354                         goto emulate_ri;
2355                 }
2356         } else {
2357                 kvm_debug("Emulate RI not supported @ %p: %#x\n", opc, inst);
2358                 goto emulate_ri;
2359         }
2360
2361         return EMULATE_DONE;
2362
2363 emulate_ri:
2364         /*
2365          * Rollback PC (if in branch delay slot then the PC already points to
2366          * branch target), and pass the RI exception to the guest OS.
2367          */
2368         vcpu->arch.pc = curr_pc;
2369         return kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
2370 }
2371
2372 enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu,
2373                                                   struct kvm_run *run)
2374 {
2375         unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
2376         enum emulation_result er = EMULATE_DONE;
2377
2378         if (run->mmio.len > sizeof(*gpr)) {
2379                 kvm_err("Bad MMIO length: %d", run->mmio.len);
2380                 er = EMULATE_FAIL;
2381                 goto done;
2382         }
2383
2384         er = update_pc(vcpu, vcpu->arch.pending_load_cause);
2385         if (er == EMULATE_FAIL)
2386                 return er;
2387
2388         switch (run->mmio.len) {
2389         case 4:
2390                 *gpr = *(int32_t *) run->mmio.data;
2391                 break;
2392
2393         case 2:
2394                 if (vcpu->mmio_needed == 2)
2395                         *gpr = *(int16_t *) run->mmio.data;
2396                 else
2397                         *gpr = *(uint16_t *)run->mmio.data;
2398
2399                 break;
2400         case 1:
2401                 if (vcpu->mmio_needed == 2)
2402                         *gpr = *(int8_t *) run->mmio.data;
2403                 else
2404                         *gpr = *(u8 *) run->mmio.data;
2405                 break;
2406         }
2407
2408         if (vcpu->arch.pending_load_cause & CAUSEF_BD)
2409                 kvm_debug("[%#lx] Completing %d byte BD Load to gpr %d (0x%08lx) type %d\n",
2410                           vcpu->arch.pc, run->mmio.len, vcpu->arch.io_gpr, *gpr,
2411                           vcpu->mmio_needed);
2412
2413 done:
2414         return er;
2415 }
2416
2417 static enum emulation_result kvm_mips_emulate_exc(unsigned long cause,
2418                                                   uint32_t *opc,
2419                                                   struct kvm_run *run,
2420                                                   struct kvm_vcpu *vcpu)
2421 {
2422         uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2423         struct mips_coproc *cop0 = vcpu->arch.cop0;
2424         struct kvm_vcpu_arch *arch = &vcpu->arch;
2425         enum emulation_result er = EMULATE_DONE;
2426
2427         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2428                 /* save old pc */
2429                 kvm_write_c0_guest_epc(cop0, arch->pc);
2430                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2431
2432                 if (cause & CAUSEF_BD)
2433                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2434                 else
2435                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2436
2437                 kvm_change_c0_guest_cause(cop0, (0xff),
2438                                           (exccode << CAUSEB_EXCCODE));
2439
2440                 /* Set PC to the exception entry point */
2441                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2442                 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2443
2444                 kvm_debug("Delivering EXC %d @ pc %#lx, badVaddr: %#lx\n",
2445                           exccode, kvm_read_c0_guest_epc(cop0),
2446                           kvm_read_c0_guest_badvaddr(cop0));
2447         } else {
2448                 kvm_err("Trying to deliver EXC when EXL is already set\n");
2449                 er = EMULATE_FAIL;
2450         }
2451
2452         return er;
2453 }
2454
2455 enum emulation_result kvm_mips_check_privilege(unsigned long cause,
2456                                                uint32_t *opc,
2457                                                struct kvm_run *run,
2458                                                struct kvm_vcpu *vcpu)
2459 {
2460         enum emulation_result er = EMULATE_DONE;
2461         uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2462         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
2463
2464         int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
2465
2466         if (usermode) {
2467                 switch (exccode) {
2468                 case EXCCODE_INT:
2469                 case EXCCODE_SYS:
2470                 case EXCCODE_BP:
2471                 case EXCCODE_RI:
2472                 case EXCCODE_TR:
2473                 case EXCCODE_MSAFPE:
2474                 case EXCCODE_FPE:
2475                 case EXCCODE_MSADIS:
2476                         break;
2477
2478                 case EXCCODE_CPU:
2479                         if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 0)
2480                                 er = EMULATE_PRIV_FAIL;
2481                         break;
2482
2483                 case EXCCODE_MOD:
2484                         break;
2485
2486                 case EXCCODE_TLBL:
2487                         /*
2488                          * We we are accessing Guest kernel space, then send an
2489                          * address error exception to the guest
2490                          */
2491                         if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
2492                                 kvm_debug("%s: LD MISS @ %#lx\n", __func__,
2493                                           badvaddr);
2494                                 cause &= ~0xff;
2495                                 cause |= (EXCCODE_ADEL << CAUSEB_EXCCODE);
2496                                 er = EMULATE_PRIV_FAIL;
2497                         }
2498                         break;
2499
2500                 case EXCCODE_TLBS:
2501                         /*
2502                          * We we are accessing Guest kernel space, then send an
2503                          * address error exception to the guest
2504                          */
2505                         if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
2506                                 kvm_debug("%s: ST MISS @ %#lx\n", __func__,
2507                                           badvaddr);
2508                                 cause &= ~0xff;
2509                                 cause |= (EXCCODE_ADES << CAUSEB_EXCCODE);
2510                                 er = EMULATE_PRIV_FAIL;
2511                         }
2512                         break;
2513
2514                 case EXCCODE_ADES:
2515                         kvm_debug("%s: address error ST @ %#lx\n", __func__,
2516                                   badvaddr);
2517                         if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
2518                                 cause &= ~0xff;
2519                                 cause |= (EXCCODE_TLBS << CAUSEB_EXCCODE);
2520                         }
2521                         er = EMULATE_PRIV_FAIL;
2522                         break;
2523                 case EXCCODE_ADEL:
2524                         kvm_debug("%s: address error LD @ %#lx\n", __func__,
2525                                   badvaddr);
2526                         if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
2527                                 cause &= ~0xff;
2528                                 cause |= (EXCCODE_TLBL << CAUSEB_EXCCODE);
2529                         }
2530                         er = EMULATE_PRIV_FAIL;
2531                         break;
2532                 default:
2533                         er = EMULATE_PRIV_FAIL;
2534                         break;
2535                 }
2536         }
2537
2538         if (er == EMULATE_PRIV_FAIL)
2539                 kvm_mips_emulate_exc(cause, opc, run, vcpu);
2540
2541         return er;
2542 }
2543
2544 /*
2545  * User Address (UA) fault, this could happen if
2546  * (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this
2547  *     case we pass on the fault to the guest kernel and let it handle it.
2548  * (2) TLB entry is present in the Guest TLB but not in the shadow, in this
2549  *     case we inject the TLB from the Guest TLB into the shadow host TLB
2550  */
2551 enum emulation_result kvm_mips_handle_tlbmiss(unsigned long cause,
2552                                               uint32_t *opc,
2553                                               struct kvm_run *run,
2554                                               struct kvm_vcpu *vcpu)
2555 {
2556         enum emulation_result er = EMULATE_DONE;
2557         uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2558         unsigned long va = vcpu->arch.host_cp0_badvaddr;
2559         int index;
2560
2561         kvm_debug("kvm_mips_handle_tlbmiss: badvaddr: %#lx, entryhi: %#lx\n",
2562                   vcpu->arch.host_cp0_badvaddr, vcpu->arch.host_cp0_entryhi);
2563
2564         /*
2565          * KVM would not have got the exception if this entry was valid in the
2566          * shadow host TLB. Check the Guest TLB, if the entry is not there then
2567          * send the guest an exception. The guest exc handler should then inject
2568          * an entry into the guest TLB.
2569          */
2570         index = kvm_mips_guest_tlb_lookup(vcpu,
2571                       (va & VPN2_MASK) |
2572                       (kvm_read_c0_guest_entryhi(vcpu->arch.cop0) & ASID_MASK));
2573         if (index < 0) {
2574                 if (exccode == EXCCODE_TLBL) {
2575                         er = kvm_mips_emulate_tlbmiss_ld(cause, opc, run, vcpu);
2576                 } else if (exccode == EXCCODE_TLBS) {
2577                         er = kvm_mips_emulate_tlbmiss_st(cause, opc, run, vcpu);
2578                 } else {
2579                         kvm_err("%s: invalid exc code: %d\n", __func__,
2580                                 exccode);
2581                         er = EMULATE_FAIL;
2582                 }
2583         } else {
2584                 struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
2585
2586                 /*
2587                  * Check if the entry is valid, if not then setup a TLB invalid
2588                  * exception to the guest
2589                  */
2590                 if (!TLB_IS_VALID(*tlb, va)) {
2591                         if (exccode == EXCCODE_TLBL) {
2592                                 er = kvm_mips_emulate_tlbinv_ld(cause, opc, run,
2593                                                                 vcpu);
2594                         } else if (exccode == EXCCODE_TLBS) {
2595                                 er = kvm_mips_emulate_tlbinv_st(cause, opc, run,
2596                                                                 vcpu);
2597                         } else {
2598                                 kvm_err("%s: invalid exc code: %d\n", __func__,
2599                                         exccode);
2600                                 er = EMULATE_FAIL;
2601                         }
2602                 } else {
2603                         kvm_debug("Injecting hi: %#lx, lo0: %#lx, lo1: %#lx into shadow host TLB\n",
2604                                   tlb->tlb_hi, tlb->tlb_lo0, tlb->tlb_lo1);
2605                         /*
2606                          * OK we have a Guest TLB entry, now inject it into the
2607                          * shadow host TLB
2608                          */
2609                         kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, NULL,
2610                                                              NULL);
2611                 }
2612         }
2613
2614         return er;
2615 }