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         struct mips_coproc *cop0 = vcpu->arch.cop0;
 306         ktime_t expires, threshold;
 307         uint32_t count, compare;
 308         int running;
 309
 310         /* Calculate the biased and scaled guest CP0_Count */
 311         count = vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now);
 312         compare = kvm_read_c0_guest_compare(cop0);
 313
 314         /*
 315          * Find whether CP0_Count has reached the closest timer interrupt. If
 316          * not, we shouldn't inject it.
 317          */
 318         if ((int32_t)(count - compare) < 0)
 319                 return count;
 320
 321         /*
 322          * The CP0_Count we're going to return has already reached the closest
 323          * timer interrupt. Quickly check if it really is a new interrupt by
 324          * looking at whether the interval until the hrtimer expiry time is
 325          * less than 1/4 of the timer period.
 326          */
 327         expires = hrtimer_get_expires(&vcpu->arch.comparecount_timer);
 328         threshold = ktime_add_ns(now, vcpu->arch.count_period / 4);
 329         if (ktime_before(expires, threshold)) {
 330                 /*
 331                  * Cancel it while we handle it so there's no chance of
 332                  * interference with the timeout handler.
 333                  */
 334                 running = hrtimer_cancel(&vcpu->arch.comparecount_timer);
 335
 336                 /* Nothing should be waiting on the timeout */
 337                 kvm_mips_callbacks->queue_timer_int(vcpu);
 338
 339                 /*
 340                  * Restart the timer if it was running based on the expiry time
 341                  * we read, so that we don't push it back 2 periods.
 342                  */
 343                 if (running) {
 344                         expires = ktime_add_ns(expires,
 345                                                vcpu->arch.count_period);
 346                         hrtimer_start(&vcpu->arch.comparecount_timer, expires,
 347                                       HRTIMER_MODE_ABS);
 348                 }
 349         }
 350
 351         return count;
 352 }
 353
 354 /**
 355  * kvm_mips_read_count() - Read the current count value.
 356  * @vcpu:       Virtual CPU.
 357  *
 358  * Read the current guest CP0_Count value, taking into account whether the timer
 359  * is stopped.
 360  *
 361  * Returns:     The current guest CP0_Count value.
 362  */
 363 uint32_t kvm_mips_read_count(struct kvm_vcpu *vcpu)
 364 {
 365         struct mips_coproc *cop0 = vcpu->arch.cop0;
 366
 367         /* If count disabled just read static copy of count */
 368         if (kvm_mips_count_disabled(vcpu))
 369                 return kvm_read_c0_guest_count(cop0);
 370
 371         return kvm_mips_read_count_running(vcpu, ktime_get());
 372 }
 373
 374 /**
 375  * kvm_mips_freeze_hrtimer() - Safely stop the hrtimer.
 376  * @vcpu:       Virtual CPU.
 377  * @count:      Output pointer for CP0_Count value at point of freeze.
 378  *
 379  * Freeze the hrtimer safely and return both the ktime and the CP0_Count value
 380  * at the point it was frozen. It is guaranteed that any pending interrupts at
 381  * the point it was frozen are handled, and none after that point.
 382  *
 383  * This is useful where the time/CP0_Count is needed in the calculation of the
 384  * new parameters.
 385  *
 386  * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
 387  *
 388  * Returns:     The ktime at the point of freeze.
 389  */
 390 static ktime_t kvm_mips_freeze_hrtimer(struct kvm_vcpu *vcpu,
 391                                        uint32_t *count)
 392 {
 393         ktime_t now;
 394
 395         /* stop hrtimer before finding time */
 396         hrtimer_cancel(&vcpu->arch.comparecount_timer);
 397         now = ktime_get();
 398
 399         /* find count at this point and handle pending hrtimer */
 400         *count = kvm_mips_read_count_running(vcpu, now);
 401
 402         return now;
 403 }
 404
 405 /**
 406  * kvm_mips_resume_hrtimer() - Resume hrtimer, updating expiry.
 407  * @vcpu:       Virtual CPU.
 408  * @now:        ktime at point of resume.
 409  * @count:      CP0_Count at point of resume.
 410  *
 411  * Resumes the timer and updates the timer expiry based on @now and @count.
 412  * This can be used in conjunction with kvm_mips_freeze_timer() when timer
 413  * parameters need to be changed.
 414  *
 415  * It is guaranteed that a timer interrupt immediately after resume will be
 416  * handled, but not if CP_Compare is exactly at @count. That case is already
 417  * handled by kvm_mips_freeze_timer().
 418  *
 419  * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
 420  */
 421 static void kvm_mips_resume_hrtimer(struct kvm_vcpu *vcpu,
 422                                     ktime_t now, uint32_t count)
 423 {
 424         struct mips_coproc *cop0 = vcpu->arch.cop0;
 425         uint32_t compare;
 426         u64 delta;
 427         ktime_t expire;
 428
 429         /* Calculate timeout (wrap 0 to 2^32) */
 430         compare = kvm_read_c0_guest_compare(cop0);
 431         delta = (u64)(uint32_t)(compare - count - 1) + 1;
 432         delta = div_u64(delta * NSEC_PER_SEC, vcpu->arch.count_hz);
 433         expire = ktime_add_ns(now, delta);
 434
 435         /* Update hrtimer to use new timeout */
 436         hrtimer_cancel(&vcpu->arch.comparecount_timer);
 437         hrtimer_start(&vcpu->arch.comparecount_timer, expire, HRTIMER_MODE_ABS);
 438 }
 439
 440 /**
 441  * kvm_mips_write_count() - Modify the count and update timer.
 442  * @vcpu:       Virtual CPU.
 443  * @count:      Guest CP0_Count value to set.
 444  *
 445  * Sets the CP0_Count value and updates the timer accordingly.
 446  */
 447 void kvm_mips_write_count(struct kvm_vcpu *vcpu, uint32_t count)
 448 {
 449         struct mips_coproc *cop0 = vcpu->arch.cop0;
 450         ktime_t now;
 451
 452         /* Calculate bias */
 453         now = kvm_mips_count_time(vcpu);
 454         vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now);
 455
 456         if (kvm_mips_count_disabled(vcpu))
 457                 /* The timer's disabled, adjust the static count */
 458                 kvm_write_c0_guest_count(cop0, count);
 459         else
 460                 /* Update timeout */
 461                 kvm_mips_resume_hrtimer(vcpu, now, count);
 462 }
 463
 464 /**
 465  * kvm_mips_init_count() - Initialise timer.
 466  * @vcpu:       Virtual CPU.
 467  *
 468  * Initialise the timer to a sensible frequency, namely 100MHz, zero it, and set
 469  * it going if it's enabled.
 470  */
 471 void kvm_mips_init_count(struct kvm_vcpu *vcpu)
 472 {
 473         /* 100 MHz */
 474         vcpu->arch.count_hz = 100*1000*1000;
 475         vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32,
 476                                           vcpu->arch.count_hz);
 477         vcpu->arch.count_dyn_bias = 0;
 478
 479         /* Starting at 0 */
 480         kvm_mips_write_count(vcpu, 0);
 481 }
 482
 483 /**
 484  * kvm_mips_set_count_hz() - Update the frequency of the timer.
 485  * @vcpu:       Virtual CPU.
 486  * @count_hz:   Frequency of CP0_Count timer in Hz.
 487  *
 488  * Change the frequency of the CP0_Count timer. This is done atomically so that
 489  * CP0_Count is continuous and no timer interrupt is lost.
 490  *
 491  * Returns:     -EINVAL if @count_hz is out of range.
 492  *              0 on success.
 493  */
 494 int kvm_mips_set_count_hz(struct kvm_vcpu *vcpu, s64 count_hz)
 495 {
 496         struct mips_coproc *cop0 = vcpu->arch.cop0;
 497         int dc;
 498         ktime_t now;
 499         u32 count;
 500
 501         /* ensure the frequency is in a sensible range... */
 502         if (count_hz <= 0 || count_hz > NSEC_PER_SEC)
 503                 return -EINVAL;
 504         /* ... and has actually changed */
 505         if (vcpu->arch.count_hz == count_hz)
 506                 return 0;
 507
 508         /* Safely freeze timer so we can keep it continuous */
 509         dc = kvm_mips_count_disabled(vcpu);
 510         if (dc) {
 511                 now = kvm_mips_count_time(vcpu);
 512                 count = kvm_read_c0_guest_count(cop0);
 513         } else {
 514                 now = kvm_mips_freeze_hrtimer(vcpu, &count);
 515         }
 516
 517         /* Update the frequency */
 518         vcpu->arch.count_hz = count_hz;
 519         vcpu->arch.count_period = div_u64((u64)NSEC_PER_SEC << 32, count_hz);
 520         vcpu->arch.count_dyn_bias = 0;
 521
 522         /* Calculate adjusted bias so dynamic count is unchanged */
 523         vcpu->arch.count_bias = count - kvm_mips_ktime_to_count(vcpu, now);
 524
 525         /* Update and resume hrtimer */
 526         if (!dc)
 527                 kvm_mips_resume_hrtimer(vcpu, now, count);
 528         return 0;
 529 }
 530
 531 /**
 532  * kvm_mips_write_compare() - Modify compare and update timer.
 533  * @vcpu:       Virtual CPU.
 534  * @compare:    New CP0_Compare value.
 535  * @ack:        Whether to acknowledge timer interrupt.
 536  *
 537  * Update CP0_Compare to a new value and update the timeout.
 538  * If @ack, atomically acknowledge any pending timer interrupt, otherwise ensure
 539  * any pending timer interrupt is preserved.
 540  */
 541 void kvm_mips_write_compare(struct kvm_vcpu *vcpu, uint32_t compare, bool ack)
 542 {
 543         struct mips_coproc *cop0 = vcpu->arch.cop0;
 544         int dc;
 545         u32 old_compare = kvm_read_c0_guest_compare(cop0);
 546         ktime_t now;
 547         uint32_t count;
 548
 549         /* if unchanged, must just be an ack */
 550         if (old_compare == compare) {
 551                 if (!ack)
 552                         return;
 553                 kvm_mips_callbacks->dequeue_timer_int(vcpu);
 554                 kvm_write_c0_guest_compare(cop0, compare);
 555                 return;
 556         }
 557
 558         /* freeze_hrtimer() takes care of timer interrupts <= count */
 559         dc = kvm_mips_count_disabled(vcpu);
 560         if (!dc)
 561                 now = kvm_mips_freeze_hrtimer(vcpu, &count);
 562
 563         if (ack)
 564                 kvm_mips_callbacks->dequeue_timer_int(vcpu);
 565
 566         kvm_write_c0_guest_compare(cop0, compare);
 567
 568         /* resume_hrtimer() takes care of timer interrupts > count */
 569         if (!dc)
 570                 kvm_mips_resume_hrtimer(vcpu, now, count);
 571 }
 572
 573 /**
 574  * kvm_mips_count_disable() - Disable count.
 575  * @vcpu:       Virtual CPU.
 576  *
 577  * Disable the CP0_Count timer. A timer interrupt on or before the final stop
 578  * time will be handled but not after.
 579  *
 580  * Assumes CP0_Count was previously enabled but now Guest.CP0_Cause.DC or
 581  * count_ctl.DC has been set (count disabled).
 582  *
 583  * Returns:     The time that the timer was stopped.
 584  */
 585 static ktime_t kvm_mips_count_disable(struct kvm_vcpu *vcpu)
 586 {
 587         struct mips_coproc *cop0 = vcpu->arch.cop0;
 588         uint32_t count;
 589         ktime_t now;
 590
 591         /* Stop hrtimer */
 592         hrtimer_cancel(&vcpu->arch.comparecount_timer);
 593
 594         /* Set the static count from the dynamic count, handling pending TI */
 595         now = ktime_get();
 596         count = kvm_mips_read_count_running(vcpu, now);
 597         kvm_write_c0_guest_count(cop0, count);
 598
 599         return now;
 600 }
 601
 602 /**
 603  * kvm_mips_count_disable_cause() - Disable count using CP0_Cause.DC.
 604  * @vcpu:       Virtual CPU.
 605  *
 606  * Disable the CP0_Count timer and set CP0_Cause.DC. A timer interrupt on or
 607  * before the final stop time will be handled if the timer isn't disabled by
 608  * count_ctl.DC, but not after.
 609  *
 610  * Assumes CP0_Cause.DC is clear (count enabled).
 611  */
 612 void kvm_mips_count_disable_cause(struct kvm_vcpu *vcpu)
 613 {
 614         struct mips_coproc *cop0 = vcpu->arch.cop0;
 615
 616         kvm_set_c0_guest_cause(cop0, CAUSEF_DC);
 617         if (!(vcpu->arch.count_ctl & KVM_REG_MIPS_COUNT_CTL_DC))
 618                 kvm_mips_count_disable(vcpu);
 619 }
 620
 621 /**
 622  * kvm_mips_count_enable_cause() - Enable count using CP0_Cause.DC.
 623  * @vcpu:       Virtual CPU.
 624  *
 625  * Enable the CP0_Count timer and clear CP0_Cause.DC. A timer interrupt after
 626  * the start time will be handled if the timer isn't disabled by count_ctl.DC,
 627  * potentially before even returning, so the caller should be careful with
 628  * ordering of CP0_Cause modifications so as not to lose it.
 629  *
 630  * Assumes CP0_Cause.DC is set (count disabled).
 631  */
 632 void kvm_mips_count_enable_cause(struct kvm_vcpu *vcpu)
 633 {
 634         struct mips_coproc *cop0 = vcpu->arch.cop0;
 635         uint32_t count;
 636
 637         kvm_clear_c0_guest_cause(cop0, CAUSEF_DC);
 638
 639         /*
 640          * Set the dynamic count to match the static count.
 641          * This starts the hrtimer if count_ctl.DC allows it.
 642          * Otherwise it conveniently updates the biases.
 643          */
 644         count = kvm_read_c0_guest_count(cop0);
 645         kvm_mips_write_count(vcpu, count);
 646 }
 647
 648 /**
 649  * kvm_mips_set_count_ctl() - Update the count control KVM register.
 650  * @vcpu:       Virtual CPU.
 651  * @count_ctl:  Count control register new value.
 652  *
 653  * Set the count control KVM register. The timer is updated accordingly.
 654  *
 655  * Returns:     -EINVAL if reserved bits are set.
 656  *              0 on success.
 657  */
 658 int kvm_mips_set_count_ctl(struct kvm_vcpu *vcpu, s64 count_ctl)
 659 {
 660         struct mips_coproc *cop0 = vcpu->arch.cop0;
 661         s64 changed = count_ctl ^ vcpu->arch.count_ctl;
 662         s64 delta;
 663         ktime_t expire, now;
 664         uint32_t count, compare;
 665
 666         /* Only allow defined bits to be changed */
 667         if (changed & ~(s64)(KVM_REG_MIPS_COUNT_CTL_DC))
 668                 return -EINVAL;
 669
 670         /* Apply new value */
 671         vcpu->arch.count_ctl = count_ctl;
 672
 673         /* Master CP0_Count disable */
 674         if (changed & KVM_REG_MIPS_COUNT_CTL_DC) {
 675                 /* Is CP0_Cause.DC already disabling CP0_Count? */
 676                 if (kvm_read_c0_guest_cause(cop0) & CAUSEF_DC) {
 677                         if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC)
 678                                 /* Just record the current time */
 679                                 vcpu->arch.count_resume = ktime_get();
 680                 } else if (count_ctl & KVM_REG_MIPS_COUNT_CTL_DC) {
 681                         /* disable timer and record current time */
 682                         vcpu->arch.count_resume = kvm_mips_count_disable(vcpu);
 683                 } else {
 684                         /*
 685                          * Calculate timeout relative to static count at resume
 686                          * time (wrap 0 to 2^32).
 687                          */
 688                         count = kvm_read_c0_guest_count(cop0);
 689                         compare = kvm_read_c0_guest_compare(cop0);
 690                         delta = (u64)(uint32_t)(compare - count - 1) + 1;
 691                         delta = div_u64(delta * NSEC_PER_SEC,
 692                                         vcpu->arch.count_hz);
 693                         expire = ktime_add_ns(vcpu->arch.count_resume, delta);
 694
 695                         /* Handle pending interrupt */
 696                         now = ktime_get();
 697                         if (ktime_compare(now, expire) >= 0)
 698                                 /* Nothing should be waiting on the timeout */
 699                                 kvm_mips_callbacks->queue_timer_int(vcpu);
 700
 701                         /* Resume hrtimer without changing bias */
 702                         count = kvm_mips_read_count_running(vcpu, now);
 703                         kvm_mips_resume_hrtimer(vcpu, now, count);
 704                 }
 705         }
 706
 707         return 0;
 708 }
 709
 710 /**
 711  * kvm_mips_set_count_resume() - Update the count resume KVM register.
 712  * @vcpu:               Virtual CPU.
 713  * @count_resume:       Count resume register new value.
 714  *
 715  * Set the count resume KVM register.
 716  *
 717  * Returns:     -EINVAL if out of valid range (0..now).
 718  *              0 on success.
 719  */
 720 int kvm_mips_set_count_resume(struct kvm_vcpu *vcpu, s64 count_resume)
 721 {
 722         /*
 723          * It doesn't make sense for the resume time to be in the future, as it
 724          * would be possible for the next interrupt to be more than a full
 725          * period in the future.
 726          */
 727         if (count_resume < 0 || count_resume > ktime_to_ns(ktime_get()))
 728                 return -EINVAL;
 729
 730         vcpu->arch.count_resume = ns_to_ktime(count_resume);
 731         return 0;
 732 }
 733
 734 /**
 735  * kvm_mips_count_timeout() - Push timer forward on timeout.
 736  * @vcpu:       Virtual CPU.
 737  *
 738  * Handle an hrtimer event by push the hrtimer forward a period.
 739  *
 740  * Returns:     The hrtimer_restart value to return to the hrtimer subsystem.
 741  */
 742 enum hrtimer_restart kvm_mips_count_timeout(struct kvm_vcpu *vcpu)
 743 {
 744         /* Add the Count period to the current expiry time */
 745         hrtimer_add_expires_ns(&vcpu->arch.comparecount_timer,
 746                                vcpu->arch.count_period);
 747         return HRTIMER_RESTART;
 748 }
 749
 750 enum emulation_result kvm_mips_emul_eret(struct kvm_vcpu *vcpu)
 751 {
 752         struct mips_coproc *cop0 = vcpu->arch.cop0;
 753         enum emulation_result er = EMULATE_DONE;
 754
 755         if (kvm_read_c0_guest_status(cop0) & ST0_EXL) {
 756                 kvm_debug("[%#lx] ERET to %#lx\n", vcpu->arch.pc,
 757                           kvm_read_c0_guest_epc(cop0));
 758                 kvm_clear_c0_guest_status(cop0, ST0_EXL);
 759                 vcpu->arch.pc = kvm_read_c0_guest_epc(cop0);
 760
 761         } else if (kvm_read_c0_guest_status(cop0) & ST0_ERL) {
 762                 kvm_clear_c0_guest_status(cop0, ST0_ERL);
 763                 vcpu->arch.pc = kvm_read_c0_guest_errorepc(cop0);
 764         } else {
 765                 kvm_err("[%#lx] ERET when MIPS_SR_EXL|MIPS_SR_ERL == 0\n",
 766                         vcpu->arch.pc);
 767                 er = EMULATE_FAIL;
 768         }
 769
 770         return er;
 771 }
 772
 773 enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
 774 {
 775         kvm_debug("[%#lx] !!!WAIT!!! (%#lx)\n", vcpu->arch.pc,
 776                   vcpu->arch.pending_exceptions);
 777
 778         ++vcpu->stat.wait_exits;
 779         trace_kvm_exit(vcpu, WAIT_EXITS);
 780         if (!vcpu->arch.pending_exceptions) {
 781                 vcpu->arch.wait = 1;
 782                 kvm_vcpu_block(vcpu);
 783
 784                 /*
 785                  * We we are runnable, then definitely go off to user space to
 786                  * check if any I/O interrupts are pending.
 787                  */
 788                 if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
 789                         clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
 790                         vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
 791                 }
 792         }
 793
 794         return EMULATE_DONE;
 795 }
 796
 797 /*
 798  * XXXKYMA: Linux doesn't seem to use TLBR, return EMULATE_FAIL for now so that
 799  * we can catch this, if things ever change
 800  */
 801 enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu)
 802 {
 803         struct mips_coproc *cop0 = vcpu->arch.cop0;
 804         uint32_t pc = vcpu->arch.pc;
 805
 806         kvm_err("[%#x] COP0_TLBR [%ld]\n", pc, kvm_read_c0_guest_index(cop0));
 807         return EMULATE_FAIL;
 808 }
 809
 810 /* Write Guest TLB Entry @ Index */
 811 enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu)
 812 {
 813         struct mips_coproc *cop0 = vcpu->arch.cop0;
 814         int index = kvm_read_c0_guest_index(cop0);
 815         struct kvm_mips_tlb *tlb = NULL;
 816         uint32_t pc = vcpu->arch.pc;
 817
 818         if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) {
 819                 kvm_debug("%s: illegal index: %d\n", __func__, index);
 820                 kvm_debug("[%#x] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
 821                           pc, index, kvm_read_c0_guest_entryhi(cop0),
 822                           kvm_read_c0_guest_entrylo0(cop0),
 823                           kvm_read_c0_guest_entrylo1(cop0),
 824                           kvm_read_c0_guest_pagemask(cop0));
 825                 index = (index & ~0x80000000) % KVM_MIPS_GUEST_TLB_SIZE;
 826         }
 827
 828         tlb = &vcpu->arch.guest_tlb[index];
 829         /*
 830          * Probe the shadow host TLB for the entry being overwritten, if one
 831          * matches, invalidate it
 832          */
 833         kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
 834
 835         tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
 836         tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
 837         tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0);
 838         tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0);
 839
 840         kvm_debug("[%#x] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
 841                   pc, index, kvm_read_c0_guest_entryhi(cop0),
 842                   kvm_read_c0_guest_entrylo0(cop0),
 843                   kvm_read_c0_guest_entrylo1(cop0),
 844                   kvm_read_c0_guest_pagemask(cop0));
 845
 846         return EMULATE_DONE;
 847 }
 848
 849 /* Write Guest TLB Entry @ Random Index */
 850 enum emulation_result kvm_mips_emul_tlbwr(struct kvm_vcpu *vcpu)
 851 {
 852         struct mips_coproc *cop0 = vcpu->arch.cop0;
 853         struct kvm_mips_tlb *tlb = NULL;
 854         uint32_t pc = vcpu->arch.pc;
 855         int index;
 856
 857         get_random_bytes(&index, sizeof(index));
 858         index &= (KVM_MIPS_GUEST_TLB_SIZE - 1);
 859
 860         tlb = &vcpu->arch.guest_tlb[index];
 861
 862         /*
 863          * Probe the shadow host TLB for the entry being overwritten, if one
 864          * matches, invalidate it
 865          */
 866         kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
 867
 868         tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
 869         tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
 870         tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0);
 871         tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0);
 872
 873         kvm_debug("[%#x] COP0_TLBWR[%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx)\n",
 874                   pc, index, kvm_read_c0_guest_entryhi(cop0),
 875                   kvm_read_c0_guest_entrylo0(cop0),
 876                   kvm_read_c0_guest_entrylo1(cop0));
 877
 878         return EMULATE_DONE;
 879 }
 880
 881 enum emulation_result kvm_mips_emul_tlbp(struct kvm_vcpu *vcpu)
 882 {
 883         struct mips_coproc *cop0 = vcpu->arch.cop0;
 884         long entryhi = kvm_read_c0_guest_entryhi(cop0);
 885         uint32_t pc = vcpu->arch.pc;
 886         int index = -1;
 887
 888         index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
 889
 890         kvm_write_c0_guest_index(cop0, index);
 891
 892         kvm_debug("[%#x] COP0_TLBP (entryhi: %#lx), index: %d\n", pc, entryhi,
 893                   index);
 894
 895         return EMULATE_DONE;
 896 }
 897
 898 /**
 899  * kvm_mips_config1_wrmask() - Find mask of writable bits in guest Config1
 900  * @vcpu:       Virtual CPU.
 901  *
 902  * Finds the mask of bits which are writable in the guest's Config1 CP0
 903  * register, by userland (currently read-only to the guest).
 904  */
 905 unsigned int kvm_mips_config1_wrmask(struct kvm_vcpu *vcpu)
 906 {
 907         unsigned int mask = 0;
 908
 909         /* Permit FPU to be present if FPU is supported */
 910         if (kvm_mips_guest_can_have_fpu(&vcpu->arch))
 911                 mask |= MIPS_CONF1_FP;
 912
 913         return mask;
 914 }
 915
 916 /**
 917  * kvm_mips_config3_wrmask() - Find mask of writable bits in guest Config3
 918  * @vcpu:       Virtual CPU.
 919  *
 920  * Finds the mask of bits which are writable in the guest's Config3 CP0
 921  * register, by userland (currently read-only to the guest).
 922  */
 923 unsigned int kvm_mips_config3_wrmask(struct kvm_vcpu *vcpu)
 924 {
 925         /* Config4 is optional */
 926         unsigned int mask = MIPS_CONF_M;
 927
 928         /* Permit MSA to be present if MSA is supported */
 929         if (kvm_mips_guest_can_have_msa(&vcpu->arch))
 930                 mask |= MIPS_CONF3_MSA;
 931
 932         return mask;
 933 }
 934
 935 /**
 936  * kvm_mips_config4_wrmask() - Find mask of writable bits in guest Config4
 937  * @vcpu:       Virtual CPU.
 938  *
 939  * Finds the mask of bits which are writable in the guest's Config4 CP0
 940  * register, by userland (currently read-only to the guest).
 941  */
 942 unsigned int kvm_mips_config4_wrmask(struct kvm_vcpu *vcpu)
 943 {
 944         /* Config5 is optional */
 945         return MIPS_CONF_M;
 946 }
 947
 948 /**
 949  * kvm_mips_config5_wrmask() - Find mask of writable bits in guest Config5
 950  * @vcpu:       Virtual CPU.
 951  *
 952  * Finds the mask of bits which are writable in the guest's Config5 CP0
 953  * register, by the guest itself.
 954  */
 955 unsigned int kvm_mips_config5_wrmask(struct kvm_vcpu *vcpu)
 956 {
 957         unsigned int mask = 0;
 958
 959         /* Permit MSAEn changes if MSA supported and enabled */
 960         if (kvm_mips_guest_has_msa(&vcpu->arch))
 961                 mask |= MIPS_CONF5_MSAEN;
 962
 963         /*
 964          * Permit guest FPU mode changes if FPU is enabled and the relevant
 965          * feature exists according to FIR register.
 966          */
 967         if (kvm_mips_guest_has_fpu(&vcpu->arch)) {
 968                 if (cpu_has_fre)
 969                         mask |= MIPS_CONF5_FRE;
 970                 /* We don't support UFR or UFE */
 971         }
 972
 973         return mask;
 974 }
 975
 976 enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc,
 977                                            uint32_t cause, struct kvm_run *run,
 978                                            struct kvm_vcpu *vcpu)
 979 {
 980         struct mips_coproc *cop0 = vcpu->arch.cop0;
 981         enum emulation_result er = EMULATE_DONE;
 982         int32_t rt, rd, copz, sel, co_bit, op;
 983         uint32_t pc = vcpu->arch.pc;
 984         unsigned long curr_pc;
 985
 986         /*
 987          * Update PC and hold onto current PC in case there is
 988          * an error and we want to rollback the PC
 989          */
 990         curr_pc = vcpu->arch.pc;
 991         er = update_pc(vcpu, cause);
 992         if (er == EMULATE_FAIL)
 993                 return er;
 994
 995         copz = (inst >> 21) & 0x1f;
 996         rt = (inst >> 16) & 0x1f;
 997         rd = (inst >> 11) & 0x1f;
 998         sel = inst & 0x7;
 999         co_bit = (inst >> 25) & 1;
1000
1001         if (co_bit) {
1002                 op = (inst) & 0xff;
1003
1004                 switch (op) {
1005                 case tlbr_op:   /*  Read indexed TLB entry  */
1006                         er = kvm_mips_emul_tlbr(vcpu);
1007                         break;
1008                 case tlbwi_op:  /*  Write indexed  */
1009                         er = kvm_mips_emul_tlbwi(vcpu);
1010                         break;
1011                 case tlbwr_op:  /*  Write random  */
1012                         er = kvm_mips_emul_tlbwr(vcpu);
1013                         break;
1014                 case tlbp_op:   /* TLB Probe */
1015                         er = kvm_mips_emul_tlbp(vcpu);
1016                         break;
1017                 case rfe_op:
1018                         kvm_err("!!!COP0_RFE!!!\n");
1019                         break;
1020                 case eret_op:
1021                         er = kvm_mips_emul_eret(vcpu);
1022                         goto dont_update_pc;
1023                         break;
1024                 case wait_op:
1025                         er = kvm_mips_emul_wait(vcpu);
1026                         break;
1027                 }
1028         } else {
1029                 switch (copz) {
1030                 case mfc_op:
1031 #ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
1032                         cop0->stat[rd][sel]++;
1033 #endif
1034                         /* Get reg */
1035                         if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
1036                                 vcpu->arch.gprs[rt] = kvm_mips_read_count(vcpu);
1037                         } else if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) {
1038                                 vcpu->arch.gprs[rt] = 0x0;
1039 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1040                                 kvm_mips_trans_mfc0(inst, opc, vcpu);
1041 #endif
1042                         } else {
1043                                 vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
1044
1045 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1046                                 kvm_mips_trans_mfc0(inst, opc, vcpu);
1047 #endif
1048                         }
1049
1050                         kvm_debug
1051                             ("[%#x] MFCz[%d][%d], vcpu->arch.gprs[%d]: %#lx\n",
1052                              pc, rd, sel, rt, vcpu->arch.gprs[rt]);
1053
1054                         break;
1055
1056                 case dmfc_op:
1057                         vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
1058                         break;
1059
1060                 case mtc_op:
1061 #ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
1062                         cop0->stat[rd][sel]++;
1063 #endif
1064                         if ((rd == MIPS_CP0_TLB_INDEX)
1065                             && (vcpu->arch.gprs[rt] >=
1066                                 KVM_MIPS_GUEST_TLB_SIZE)) {
1067                                 kvm_err("Invalid TLB Index: %ld",
1068                                         vcpu->arch.gprs[rt]);
1069                                 er = EMULATE_FAIL;
1070                                 break;
1071                         }
1072 #define C0_EBASE_CORE_MASK 0xff
1073                         if ((rd == MIPS_CP0_PRID) && (sel == 1)) {
1074                                 /* Preserve CORE number */
1075                                 kvm_change_c0_guest_ebase(cop0,
1076                                                           ~(C0_EBASE_CORE_MASK),
1077                                                           vcpu->arch.gprs[rt]);
1078                                 kvm_err("MTCz, cop0->reg[EBASE]: %#lx\n",
1079                                         kvm_read_c0_guest_ebase(cop0));
1080                         } else if (rd == MIPS_CP0_TLB_HI && sel == 0) {
1081                                 uint32_t nasid =
1082                                         vcpu->arch.gprs[rt] & KVM_ENTRYHI_ASID;
1083                                 if ((KSEGX(vcpu->arch.gprs[rt]) != CKSEG0) &&
1084                                     ((kvm_read_c0_guest_entryhi(cop0) &
1085                                       KVM_ENTRYHI_ASID) != nasid)) {
1086                                         kvm_debug("MTCz, change ASID from %#lx to %#lx\n",
1087                                                 kvm_read_c0_guest_entryhi(cop0)
1088                                                 & KVM_ENTRYHI_ASID,
1089                                                 vcpu->arch.gprs[rt]
1090                                                 & KVM_ENTRYHI_ASID);
1091
1092                                         /* Blow away the shadow host TLBs */
1093                                         kvm_mips_flush_host_tlb(1);
1094                                 }
1095                                 kvm_write_c0_guest_entryhi(cop0,
1096                                                            vcpu->arch.gprs[rt]);
1097                         }
1098                         /* Are we writing to COUNT */
1099                         else if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
1100                                 kvm_mips_write_count(vcpu, vcpu->arch.gprs[rt]);
1101                                 goto done;
1102                         } else if ((rd == MIPS_CP0_COMPARE) && (sel == 0)) {
1103                                 kvm_debug("[%#x] MTCz, COMPARE %#lx <- %#lx\n",
1104                                           pc, kvm_read_c0_guest_compare(cop0),
1105                                           vcpu->arch.gprs[rt]);
1106
1107                                 /* If we are writing to COMPARE */
1108                                 /* Clear pending timer interrupt, if any */
1109                                 kvm_mips_write_compare(vcpu,
1110                                                        vcpu->arch.gprs[rt],
1111                                                        true);
1112                         } else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) {
1113                                 unsigned int old_val, val, change;
1114
1115                                 old_val = kvm_read_c0_guest_status(cop0);
1116                                 val = vcpu->arch.gprs[rt];
1117                                 change = val ^ old_val;
1118
1119                                 /* Make sure that the NMI bit is never set */
1120                                 val &= ~ST0_NMI;
1121
1122                                 /*
1123                                  * Don't allow CU1 or FR to be set unless FPU
1124                                  * capability enabled and exists in guest
1125                                  * configuration.
1126                                  */
1127                                 if (!kvm_mips_guest_has_fpu(&vcpu->arch))
1128                                         val &= ~(ST0_CU1 | ST0_FR);
1129
1130                                 /*
1131                                  * Also don't allow FR to be set if host doesn't
1132                                  * support it.
1133                                  */
1134                                 if (!(current_cpu_data.fpu_id & MIPS_FPIR_F64))
1135                                         val &= ~ST0_FR;
1136
1137
1138                                 /* Handle changes in FPU mode */
1139                                 preempt_disable();
1140
1141                                 /*
1142                                  * FPU and Vector register state is made
1143                                  * UNPREDICTABLE by a change of FR, so don't
1144                                  * even bother saving it.
1145                                  */
1146                                 if (change & ST0_FR)
1147                                         kvm_drop_fpu(vcpu);
1148
1149                                 /*
1150                                  * If MSA state is already live, it is undefined
1151                                  * how it interacts with FR=0 FPU state, and we
1152                                  * don't want to hit reserved instruction
1153                                  * exceptions trying to save the MSA state later
1154                                  * when CU=1 && FR=1, so play it safe and save
1155                                  * it first.
1156                                  */
1157                                 if (change & ST0_CU1 && !(val & ST0_FR) &&
1158                                     vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA)
1159                                         kvm_lose_fpu(vcpu);
1160
1161                                 /*
1162                                  * Propagate CU1 (FPU enable) changes
1163                                  * immediately if the FPU context is already
1164                                  * loaded. When disabling we leave the context
1165                                  * loaded so it can be quickly enabled again in
1166                                  * the near future.
1167                                  */
1168                                 if (change & ST0_CU1 &&
1169                                     vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)
1170                                         change_c0_status(ST0_CU1, val);
1171
1172                                 preempt_enable();
1173
1174                                 kvm_write_c0_guest_status(cop0, val);
1175
1176 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1177                                 /*
1178                                  * If FPU present, we need CU1/FR bits to take
1179                                  * effect fairly soon.
1180                                  */
1181                                 if (!kvm_mips_guest_has_fpu(&vcpu->arch))
1182                                         kvm_mips_trans_mtc0(inst, opc, vcpu);
1183 #endif
1184                         } else if ((rd == MIPS_CP0_CONFIG) && (sel == 5)) {
1185                                 unsigned int old_val, val, change, wrmask;
1186
1187                                 old_val = kvm_read_c0_guest_config5(cop0);
1188                                 val = vcpu->arch.gprs[rt];
1189
1190                                 /* Only a few bits are writable in Config5 */
1191                                 wrmask = kvm_mips_config5_wrmask(vcpu);
1192                                 change = (val ^ old_val) & wrmask;
1193                                 val = old_val ^ change;
1194
1195
1196                                 /* Handle changes in FPU/MSA modes */
1197                                 preempt_disable();
1198
1199                                 /*
1200                                  * Propagate FRE changes immediately if the FPU
1201                                  * context is already loaded.
1202                                  */
1203                                 if (change & MIPS_CONF5_FRE &&
1204                                     vcpu->arch.fpu_inuse & KVM_MIPS_FPU_FPU)
1205                                         change_c0_config5(MIPS_CONF5_FRE, val);
1206
1207                                 /*
1208                                  * Propagate MSAEn changes immediately if the
1209                                  * MSA context is already loaded. When disabling
1210                                  * we leave the context loaded so it can be
1211                                  * quickly enabled again in the near future.
1212                                  */
1213                                 if (change & MIPS_CONF5_MSAEN &&
1214                                     vcpu->arch.fpu_inuse & KVM_MIPS_FPU_MSA)
1215                                         change_c0_config5(MIPS_CONF5_MSAEN,
1216                                                           val);
1217
1218                                 preempt_enable();
1219
1220                                 kvm_write_c0_guest_config5(cop0, val);
1221                         } else if ((rd == MIPS_CP0_CAUSE) && (sel == 0)) {
1222                                 uint32_t old_cause, new_cause;
1223
1224                                 old_cause = kvm_read_c0_guest_cause(cop0);
1225                                 new_cause = vcpu->arch.gprs[rt];
1226                                 /* Update R/W bits */
1227                                 kvm_change_c0_guest_cause(cop0, 0x08800300,
1228                                                           new_cause);
1229                                 /* DC bit enabling/disabling timer? */
1230                                 if ((old_cause ^ new_cause) & CAUSEF_DC) {
1231                                         if (new_cause & CAUSEF_DC)
1232                                                 kvm_mips_count_disable_cause(vcpu);
1233                                         else
1234                                                 kvm_mips_count_enable_cause(vcpu);
1235                                 }
1236                         } else {
1237                                 cop0->reg[rd][sel] = vcpu->arch.gprs[rt];
1238 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1239                                 kvm_mips_trans_mtc0(inst, opc, vcpu);
1240 #endif
1241                         }
1242
1243                         kvm_debug("[%#x] MTCz, cop0->reg[%d][%d]: %#lx\n", pc,
1244                                   rd, sel, cop0->reg[rd][sel]);
1245                         break;
1246
1247                 case dmtc_op:
1248                         kvm_err("!!!!!!![%#lx]dmtc_op: rt: %d, rd: %d, sel: %d!!!!!!\n",
1249                                 vcpu->arch.pc, rt, rd, sel);
1250                         er = EMULATE_FAIL;
1251                         break;
1252
1253                 case mfmc0_op:
1254 #ifdef KVM_MIPS_DEBUG_COP0_COUNTERS
1255                         cop0->stat[MIPS_CP0_STATUS][0]++;
1256 #endif
1257                         if (rt != 0)
1258                                 vcpu->arch.gprs[rt] =
1259                                     kvm_read_c0_guest_status(cop0);
1260                         /* EI */
1261                         if (inst & 0x20) {
1262                                 kvm_debug("[%#lx] mfmc0_op: EI\n",
1263                                           vcpu->arch.pc);
1264                                 kvm_set_c0_guest_status(cop0, ST0_IE);
1265                         } else {
1266                                 kvm_debug("[%#lx] mfmc0_op: DI\n",
1267                                           vcpu->arch.pc);
1268                                 kvm_clear_c0_guest_status(cop0, ST0_IE);
1269                         }
1270
1271                         break;
1272
1273                 case wrpgpr_op:
1274                         {
1275                                 uint32_t css =
1276                                     cop0->reg[MIPS_CP0_STATUS][2] & 0xf;
1277                                 uint32_t pss =
1278                                     (cop0->reg[MIPS_CP0_STATUS][2] >> 6) & 0xf;
1279                                 /*
1280                                  * We don't support any shadow register sets, so
1281                                  * SRSCtl[PSS] == SRSCtl[CSS] = 0
1282                                  */
1283                                 if (css || pss) {
1284                                         er = EMULATE_FAIL;
1285                                         break;
1286                                 }
1287                                 kvm_debug("WRPGPR[%d][%d] = %#lx\n", pss, rd,
1288                                           vcpu->arch.gprs[rt]);
1289                                 vcpu->arch.gprs[rd] = vcpu->arch.gprs[rt];
1290                         }
1291                         break;
1292                 default:
1293                         kvm_err("[%#lx]MachEmulateCP0: unsupported COP0, copz: 0x%x\n",
1294                                 vcpu->arch.pc, copz);
1295                         er = EMULATE_FAIL;
1296                         break;
1297                 }
1298         }
1299
1300 done:
1301         /* Rollback PC only if emulation was unsuccessful */
1302         if (er == EMULATE_FAIL)
1303                 vcpu->arch.pc = curr_pc;
1304
1305 dont_update_pc:
1306         /*
1307          * This is for special instructions whose emulation
1308          * updates the PC, so do not overwrite the PC under
1309          * any circumstances
1310          */
1311
1312         return er;
1313 }
1314
1315 enum emulation_result kvm_mips_emulate_store(uint32_t inst, uint32_t cause,
1316                                              struct kvm_run *run,
1317                                              struct kvm_vcpu *vcpu)
1318 {
1319         enum emulation_result er = EMULATE_DO_MMIO;
1320         int32_t op, base, rt, offset;
1321         uint32_t bytes;
1322         void *data = run->mmio.data;
1323         unsigned long curr_pc;
1324
1325         /*
1326          * Update PC and hold onto current PC in case there is
1327          * an error and we want to rollback the PC
1328          */
1329         curr_pc = vcpu->arch.pc;
1330         er = update_pc(vcpu, cause);
1331         if (er == EMULATE_FAIL)
1332                 return er;
1333
1334         rt = (inst >> 16) & 0x1f;
1335         base = (inst >> 21) & 0x1f;
1336         offset = inst & 0xffff;
1337         op = (inst >> 26) & 0x3f;
1338
1339         switch (op) {
1340         case sb_op:
1341                 bytes = 1;
1342                 if (bytes > sizeof(run->mmio.data)) {
1343                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1344                                run->mmio.len);
1345                 }
1346                 run->mmio.phys_addr =
1347                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1348                                                    host_cp0_badvaddr);
1349                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1350                         er = EMULATE_FAIL;
1351                         break;
1352                 }
1353                 run->mmio.len = bytes;
1354                 run->mmio.is_write = 1;
1355                 vcpu->mmio_needed = 1;
1356                 vcpu->mmio_is_write = 1;
1357                 *(u8 *) data = vcpu->arch.gprs[rt];
1358                 kvm_debug("OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1359                           vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt],
1360                           *(uint8_t *) data);
1361
1362                 break;
1363
1364         case sw_op:
1365                 bytes = 4;
1366                 if (bytes > sizeof(run->mmio.data)) {
1367                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1368                                run->mmio.len);
1369                 }
1370                 run->mmio.phys_addr =
1371                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1372                                                    host_cp0_badvaddr);
1373                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1374                         er = EMULATE_FAIL;
1375                         break;
1376                 }
1377
1378                 run->mmio.len = bytes;
1379                 run->mmio.is_write = 1;
1380                 vcpu->mmio_needed = 1;
1381                 vcpu->mmio_is_write = 1;
1382                 *(uint32_t *) data = vcpu->arch.gprs[rt];
1383
1384                 kvm_debug("[%#lx] OP_SW: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1385                           vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1386                           vcpu->arch.gprs[rt], *(uint32_t *) data);
1387                 break;
1388
1389         case sh_op:
1390                 bytes = 2;
1391                 if (bytes > sizeof(run->mmio.data)) {
1392                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1393                                run->mmio.len);
1394                 }
1395                 run->mmio.phys_addr =
1396                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1397                                                    host_cp0_badvaddr);
1398                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1399                         er = EMULATE_FAIL;
1400                         break;
1401                 }
1402
1403                 run->mmio.len = bytes;
1404                 run->mmio.is_write = 1;
1405                 vcpu->mmio_needed = 1;
1406                 vcpu->mmio_is_write = 1;
1407                 *(uint16_t *) data = vcpu->arch.gprs[rt];
1408
1409                 kvm_debug("[%#lx] OP_SH: eaddr: %#lx, gpr: %#lx, data: %#x\n",
1410                           vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
1411                           vcpu->arch.gprs[rt], *(uint32_t *) data);
1412                 break;
1413
1414         default:
1415                 kvm_err("Store not yet supported");
1416                 er = EMULATE_FAIL;
1417                 break;
1418         }
1419
1420         /* Rollback PC if emulation was unsuccessful */
1421         if (er == EMULATE_FAIL)
1422                 vcpu->arch.pc = curr_pc;
1423
1424         return er;
1425 }
1426
1427 enum emulation_result kvm_mips_emulate_load(uint32_t inst, uint32_t cause,
1428                                             struct kvm_run *run,
1429                                             struct kvm_vcpu *vcpu)
1430 {
1431         enum emulation_result er = EMULATE_DO_MMIO;
1432         int32_t op, base, rt, offset;
1433         uint32_t bytes;
1434
1435         rt = (inst >> 16) & 0x1f;
1436         base = (inst >> 21) & 0x1f;
1437         offset = inst & 0xffff;
1438         op = (inst >> 26) & 0x3f;
1439
1440         vcpu->arch.pending_load_cause = cause;
1441         vcpu->arch.io_gpr = rt;
1442
1443         switch (op) {
1444         case lw_op:
1445                 bytes = 4;
1446                 if (bytes > sizeof(run->mmio.data)) {
1447                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1448                                run->mmio.len);
1449                         er = EMULATE_FAIL;
1450                         break;
1451                 }
1452                 run->mmio.phys_addr =
1453                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1454                                                    host_cp0_badvaddr);
1455                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1456                         er = EMULATE_FAIL;
1457                         break;
1458                 }
1459
1460                 run->mmio.len = bytes;
1461                 run->mmio.is_write = 0;
1462                 vcpu->mmio_needed = 1;
1463                 vcpu->mmio_is_write = 0;
1464                 break;
1465
1466         case lh_op:
1467         case lhu_op:
1468                 bytes = 2;
1469                 if (bytes > sizeof(run->mmio.data)) {
1470                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1471                                run->mmio.len);
1472                         er = EMULATE_FAIL;
1473                         break;
1474                 }
1475                 run->mmio.phys_addr =
1476                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1477                                                    host_cp0_badvaddr);
1478                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1479                         er = EMULATE_FAIL;
1480                         break;
1481                 }
1482
1483                 run->mmio.len = bytes;
1484                 run->mmio.is_write = 0;
1485                 vcpu->mmio_needed = 1;
1486                 vcpu->mmio_is_write = 0;
1487
1488                 if (op == lh_op)
1489                         vcpu->mmio_needed = 2;
1490                 else
1491                         vcpu->mmio_needed = 1;
1492
1493                 break;
1494
1495         case lbu_op:
1496         case lb_op:
1497                 bytes = 1;
1498                 if (bytes > sizeof(run->mmio.data)) {
1499                         kvm_err("%s: bad MMIO length: %d\n", __func__,
1500                                run->mmio.len);
1501                         er = EMULATE_FAIL;
1502                         break;
1503                 }
1504                 run->mmio.phys_addr =
1505                     kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
1506                                                    host_cp0_badvaddr);
1507                 if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
1508                         er = EMULATE_FAIL;
1509                         break;
1510                 }
1511
1512                 run->mmio.len = bytes;
1513                 run->mmio.is_write = 0;
1514                 vcpu->mmio_is_write = 0;
1515
1516                 if (op == lb_op)
1517                         vcpu->mmio_needed = 2;
1518                 else
1519                         vcpu->mmio_needed = 1;
1520
1521                 break;
1522
1523         default:
1524                 kvm_err("Load not yet supported");
1525                 er = EMULATE_FAIL;
1526                 break;
1527         }
1528
1529         return er;
1530 }
1531
1532 int kvm_mips_sync_icache(unsigned long va, struct kvm_vcpu *vcpu)
1533 {
1534         unsigned long offset = (va & ~PAGE_MASK);
1535         struct kvm *kvm = vcpu->kvm;
1536         unsigned long pa;
1537         gfn_t gfn;
1538         kvm_pfn_t pfn;
1539
1540         gfn = va >> PAGE_SHIFT;
1541
1542         if (gfn >= kvm->arch.guest_pmap_npages) {
1543                 kvm_err("%s: Invalid gfn: %#llx\n", __func__, gfn);
1544                 kvm_mips_dump_host_tlbs();
1545                 kvm_arch_vcpu_dump_regs(vcpu);
1546                 return -1;
1547         }
1548         pfn = kvm->arch.guest_pmap[gfn];
1549         pa = (pfn << PAGE_SHIFT) | offset;
1550
1551         kvm_debug("%s: va: %#lx, unmapped: %#x\n", __func__, va,
1552                   CKSEG0ADDR(pa));
1553
1554         local_flush_icache_range(CKSEG0ADDR(pa), 32);
1555         return 0;
1556 }
1557
1558 enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc,
1559                                              uint32_t cause,
1560                                              struct kvm_run *run,
1561                                              struct kvm_vcpu *vcpu)
1562 {
1563         struct mips_coproc *cop0 = vcpu->arch.cop0;
1564         enum emulation_result er = EMULATE_DONE;
1565         int32_t offset, cache, op_inst, op, base;
1566         struct kvm_vcpu_arch *arch = &vcpu->arch;
1567         unsigned long va;
1568         unsigned long curr_pc;
1569
1570         /*
1571          * Update PC and hold onto current PC in case there is
1572          * an error and we want to rollback the PC
1573          */
1574         curr_pc = vcpu->arch.pc;
1575         er = update_pc(vcpu, cause);
1576         if (er == EMULATE_FAIL)
1577                 return er;
1578
1579         base = (inst >> 21) & 0x1f;
1580         op_inst = (inst >> 16) & 0x1f;
1581         offset = (int16_t)inst;
1582         cache = op_inst & CacheOp_Cache;
1583         op = op_inst & CacheOp_Op;
1584
1585         va = arch->gprs[base] + offset;
1586
1587         kvm_debug("CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1588                   cache, op, base, arch->gprs[base], offset);
1589
1590         /*
1591          * Treat INDEX_INV as a nop, basically issued by Linux on startup to
1592          * invalidate the caches entirely by stepping through all the
1593          * ways/indexes
1594          */
1595         if (op == Index_Writeback_Inv) {
1596                 kvm_debug("@ %#lx/%#lx CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1597                           vcpu->arch.pc, vcpu->arch.gprs[31], cache, op, base,
1598                           arch->gprs[base], offset);
1599
1600                 if (cache == Cache_D)
1601                         r4k_blast_dcache();
1602                 else if (cache == Cache_I)
1603                         r4k_blast_icache();
1604                 else {
1605                         kvm_err("%s: unsupported CACHE INDEX operation\n",
1606                                 __func__);
1607                         return EMULATE_FAIL;
1608                 }
1609
1610 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1611                 kvm_mips_trans_cache_index(inst, opc, vcpu);
1612 #endif
1613                 goto done;
1614         }
1615
1616         preempt_disable();
1617         if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
1618                 if (kvm_mips_host_tlb_lookup(vcpu, va) < 0)
1619                         kvm_mips_handle_kseg0_tlb_fault(va, vcpu);
1620         } else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) ||
1621                    KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
1622                 int index;
1623
1624                 /* If an entry already exists then skip */
1625                 if (kvm_mips_host_tlb_lookup(vcpu, va) >= 0)
1626                         goto skip_fault;
1627
1628                 /*
1629                  * If address not in the guest TLB, then give the guest a fault,
1630                  * the resulting handler will do the right thing
1631                  */
1632                 index = kvm_mips_guest_tlb_lookup(vcpu, (va & VPN2_MASK) |
1633                                                   (kvm_read_c0_guest_entryhi
1634                                                    (cop0) & KVM_ENTRYHI_ASID));
1635
1636                 if (index < 0) {
1637                         vcpu->arch.host_cp0_entryhi = (va & VPN2_MASK);
1638                         vcpu->arch.host_cp0_badvaddr = va;
1639                         vcpu->arch.pc = curr_pc;
1640                         er = kvm_mips_emulate_tlbmiss_ld(cause, NULL, run,
1641                                                          vcpu);
1642                         preempt_enable();
1643                         goto dont_update_pc;
1644                 } else {
1645                         struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
1646                         /*
1647                          * Check if the entry is valid, if not then setup a TLB
1648                          * invalid exception to the guest
1649                          */
1650                         if (!TLB_IS_VALID(*tlb, va)) {
1651                                 vcpu->arch.host_cp0_badvaddr = va;
1652                                 vcpu->arch.pc = curr_pc;
1653                                 er = kvm_mips_emulate_tlbinv_ld(cause, NULL,
1654                                                                 run, vcpu);
1655                                 preempt_enable();
1656                                 goto dont_update_pc;
1657                         } else {
1658                                 /*
1659                                  * We fault an entry from the guest tlb to the
1660                                  * shadow host TLB
1661                                  */
1662                                 kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
1663                                                                      NULL,
1664                                                                      NULL);
1665                         }
1666                 }
1667         } else {
1668                 kvm_err("INVALID CACHE INDEX/ADDRESS (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1669                         cache, op, base, arch->gprs[base], offset);
1670                 er = EMULATE_FAIL;
1671                 preempt_enable();
1672                 goto done;
1673
1674         }
1675
1676 skip_fault:
1677         /* XXXKYMA: Only a subset of cache ops are supported, used by Linux */
1678         if (op_inst == Hit_Writeback_Inv_D || op_inst == Hit_Invalidate_D) {
1679                 flush_dcache_line(va);
1680
1681 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1682                 /*
1683                  * Replace the CACHE instruction, with a SYNCI, not the same,
1684                  * but avoids a trap
1685                  */
1686                 kvm_mips_trans_cache_va(inst, opc, vcpu);
1687 #endif
1688         } else if (op_inst == Hit_Invalidate_I) {
1689                 flush_dcache_line(va);
1690                 flush_icache_line(va);
1691
1692 #ifdef CONFIG_KVM_MIPS_DYN_TRANS
1693                 /* Replace the CACHE instruction, with a SYNCI */
1694                 kvm_mips_trans_cache_va(inst, opc, vcpu);
1695 #endif
1696         } else {
1697                 kvm_err("NO-OP CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1698                         cache, op, base, arch->gprs[base], offset);
1699                 er = EMULATE_FAIL;
1700         }
1701
1702         preempt_enable();
1703 done:
1704         /* Rollback PC only if emulation was unsuccessful */
1705         if (er == EMULATE_FAIL)
1706                 vcpu->arch.pc = curr_pc;
1707
1708 dont_update_pc:
1709         /*
1710          * This is for exceptions whose emulation updates the PC, so do not
1711          * overwrite the PC under any circumstances
1712          */
1713
1714         return er;
1715 }
1716
1717 enum emulation_result kvm_mips_emulate_inst(unsigned long cause, uint32_t *opc,
1718                                             struct kvm_run *run,
1719                                             struct kvm_vcpu *vcpu)
1720 {
1721         enum emulation_result er = EMULATE_DONE;
1722         uint32_t inst;
1723
1724         /* Fetch the instruction. */
1725         if (cause & CAUSEF_BD)
1726                 opc += 1;
1727
1728         inst = kvm_get_inst(opc, vcpu);
1729
1730         switch (((union mips_instruction)inst).r_format.opcode) {
1731         case cop0_op:
1732                 er = kvm_mips_emulate_CP0(inst, opc, cause, run, vcpu);
1733                 break;
1734         case sb_op:
1735         case sh_op:
1736         case sw_op:
1737                 er = kvm_mips_emulate_store(inst, cause, run, vcpu);
1738                 break;
1739         case lb_op:
1740         case lbu_op:
1741         case lhu_op:
1742         case lh_op:
1743         case lw_op:
1744                 er = kvm_mips_emulate_load(inst, cause, run, vcpu);
1745                 break;
1746
1747         case cache_op:
1748                 ++vcpu->stat.cache_exits;
1749                 trace_kvm_exit(vcpu, CACHE_EXITS);
1750                 er = kvm_mips_emulate_cache(inst, opc, cause, run, vcpu);
1751                 break;
1752
1753         default:
1754                 kvm_err("Instruction emulation not supported (%p/%#x)\n", opc,
1755                         inst);
1756                 kvm_arch_vcpu_dump_regs(vcpu);
1757                 er = EMULATE_FAIL;
1758                 break;
1759         }
1760
1761         return er;
1762 }
1763
1764 enum emulation_result kvm_mips_emulate_syscall(unsigned long cause,
1765                                                uint32_t *opc,
1766                                                struct kvm_run *run,
1767                                                struct kvm_vcpu *vcpu)
1768 {
1769         struct mips_coproc *cop0 = vcpu->arch.cop0;
1770         struct kvm_vcpu_arch *arch = &vcpu->arch;
1771         enum emulation_result er = EMULATE_DONE;
1772
1773         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1774                 /* save old pc */
1775                 kvm_write_c0_guest_epc(cop0, arch->pc);
1776                 kvm_set_c0_guest_status(cop0, ST0_EXL);
1777
1778                 if (cause & CAUSEF_BD)
1779                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1780                 else
1781                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1782
1783                 kvm_debug("Delivering SYSCALL @ pc %#lx\n", arch->pc);
1784
1785                 kvm_change_c0_guest_cause(cop0, (0xff),
1786                                           (EXCCODE_SYS << CAUSEB_EXCCODE));
1787
1788                 /* Set PC to the exception entry point */
1789                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1790
1791         } else {
1792                 kvm_err("Trying to deliver SYSCALL when EXL is already set\n");
1793                 er = EMULATE_FAIL;
1794         }
1795
1796         return er;
1797 }
1798
1799 enum emulation_result kvm_mips_emulate_tlbmiss_ld(unsigned long cause,
1800                                                   uint32_t *opc,
1801                                                   struct kvm_run *run,
1802                                                   struct kvm_vcpu *vcpu)
1803 {
1804         struct mips_coproc *cop0 = vcpu->arch.cop0;
1805         struct kvm_vcpu_arch *arch = &vcpu->arch;
1806         unsigned long entryhi = (vcpu->arch.  host_cp0_badvaddr & VPN2_MASK) |
1807                         (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
1808
1809         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1810                 /* save old pc */
1811                 kvm_write_c0_guest_epc(cop0, arch->pc);
1812                 kvm_set_c0_guest_status(cop0, ST0_EXL);
1813
1814                 if (cause & CAUSEF_BD)
1815                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1816                 else
1817                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1818
1819                 kvm_debug("[EXL == 0] delivering TLB MISS @ pc %#lx\n",
1820                           arch->pc);
1821
1822                 /* set pc to the exception entry point */
1823                 arch->pc = KVM_GUEST_KSEG0 + 0x0;
1824
1825         } else {
1826                 kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1827                           arch->pc);
1828
1829                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1830         }
1831
1832         kvm_change_c0_guest_cause(cop0, (0xff),
1833                                   (EXCCODE_TLBL << CAUSEB_EXCCODE));
1834
1835         /* setup badvaddr, context and entryhi registers for the guest */
1836         kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1837         /* XXXKYMA: is the context register used by linux??? */
1838         kvm_write_c0_guest_entryhi(cop0, entryhi);
1839         /* Blow away the shadow host TLBs */
1840         kvm_mips_flush_host_tlb(1);
1841
1842         return EMULATE_DONE;
1843 }
1844
1845 enum emulation_result kvm_mips_emulate_tlbinv_ld(unsigned long cause,
1846                                                  uint32_t *opc,
1847                                                  struct kvm_run *run,
1848                                                  struct kvm_vcpu *vcpu)
1849 {
1850         struct mips_coproc *cop0 = vcpu->arch.cop0;
1851         struct kvm_vcpu_arch *arch = &vcpu->arch;
1852         unsigned long entryhi =
1853                 (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1854                 (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
1855
1856         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1857                 /* save old pc */
1858                 kvm_write_c0_guest_epc(cop0, arch->pc);
1859                 kvm_set_c0_guest_status(cop0, ST0_EXL);
1860
1861                 if (cause & CAUSEF_BD)
1862                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1863                 else
1864                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1865
1866                 kvm_debug("[EXL == 0] delivering TLB INV @ pc %#lx\n",
1867                           arch->pc);
1868
1869                 /* set pc to the exception entry point */
1870                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1871
1872         } else {
1873                 kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1874                           arch->pc);
1875                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1876         }
1877
1878         kvm_change_c0_guest_cause(cop0, (0xff),
1879                                   (EXCCODE_TLBL << CAUSEB_EXCCODE));
1880
1881         /* setup badvaddr, context and entryhi registers for the guest */
1882         kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1883         /* XXXKYMA: is the context register used by linux??? */
1884         kvm_write_c0_guest_entryhi(cop0, entryhi);
1885         /* Blow away the shadow host TLBs */
1886         kvm_mips_flush_host_tlb(1);
1887
1888         return EMULATE_DONE;
1889 }
1890
1891 enum emulation_result kvm_mips_emulate_tlbmiss_st(unsigned long cause,
1892                                                   uint32_t *opc,
1893                                                   struct kvm_run *run,
1894                                                   struct kvm_vcpu *vcpu)
1895 {
1896         struct mips_coproc *cop0 = vcpu->arch.cop0;
1897         struct kvm_vcpu_arch *arch = &vcpu->arch;
1898         unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1899                         (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
1900
1901         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1902                 /* save old pc */
1903                 kvm_write_c0_guest_epc(cop0, arch->pc);
1904                 kvm_set_c0_guest_status(cop0, ST0_EXL);
1905
1906                 if (cause & CAUSEF_BD)
1907                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1908                 else
1909                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1910
1911                 kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
1912                           arch->pc);
1913
1914                 /* Set PC to the exception entry point */
1915                 arch->pc = KVM_GUEST_KSEG0 + 0x0;
1916         } else {
1917                 kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
1918                           arch->pc);
1919                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1920         }
1921
1922         kvm_change_c0_guest_cause(cop0, (0xff),
1923                                   (EXCCODE_TLBS << CAUSEB_EXCCODE));
1924
1925         /* setup badvaddr, context and entryhi registers for the guest */
1926         kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1927         /* XXXKYMA: is the context register used by linux??? */
1928         kvm_write_c0_guest_entryhi(cop0, entryhi);
1929         /* Blow away the shadow host TLBs */
1930         kvm_mips_flush_host_tlb(1);
1931
1932         return EMULATE_DONE;
1933 }
1934
1935 enum emulation_result kvm_mips_emulate_tlbinv_st(unsigned long cause,
1936                                                  uint32_t *opc,
1937                                                  struct kvm_run *run,
1938                                                  struct kvm_vcpu *vcpu)
1939 {
1940         struct mips_coproc *cop0 = vcpu->arch.cop0;
1941         struct kvm_vcpu_arch *arch = &vcpu->arch;
1942         unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1943                 (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
1944
1945         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1946                 /* save old pc */
1947                 kvm_write_c0_guest_epc(cop0, arch->pc);
1948                 kvm_set_c0_guest_status(cop0, ST0_EXL);
1949
1950                 if (cause & CAUSEF_BD)
1951                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1952                 else
1953                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1954
1955                 kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
1956                           arch->pc);
1957
1958                 /* Set PC to the exception entry point */
1959                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1960         } else {
1961                 kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
1962                           arch->pc);
1963                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
1964         }
1965
1966         kvm_change_c0_guest_cause(cop0, (0xff),
1967                                   (EXCCODE_TLBS << CAUSEB_EXCCODE));
1968
1969         /* setup badvaddr, context and entryhi registers for the guest */
1970         kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1971         /* XXXKYMA: is the context register used by linux??? */
1972         kvm_write_c0_guest_entryhi(cop0, entryhi);
1973         /* Blow away the shadow host TLBs */
1974         kvm_mips_flush_host_tlb(1);
1975
1976         return EMULATE_DONE;
1977 }
1978
1979 /* TLBMOD: store into address matching TLB with Dirty bit off */
1980 enum emulation_result kvm_mips_handle_tlbmod(unsigned long cause, uint32_t *opc,
1981                                              struct kvm_run *run,
1982                                              struct kvm_vcpu *vcpu)
1983 {
1984         enum emulation_result er = EMULATE_DONE;
1985 #ifdef DEBUG
1986         struct mips_coproc *cop0 = vcpu->arch.cop0;
1987         unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1988                         (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
1989         int index;
1990
1991         /* If address not in the guest TLB, then we are in trouble */
1992         index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
1993         if (index < 0) {
1994                 /* XXXKYMA Invalidate and retry */
1995                 kvm_mips_host_tlb_inv(vcpu, vcpu->arch.host_cp0_badvaddr);
1996                 kvm_err("%s: host got TLBMOD for %#lx but entry not present in Guest TLB\n",
1997                      __func__, entryhi);
1998                 kvm_mips_dump_guest_tlbs(vcpu);
1999                 kvm_mips_dump_host_tlbs();
2000                 return EMULATE_FAIL;
2001         }
2002 #endif
2003
2004         er = kvm_mips_emulate_tlbmod(cause, opc, run, vcpu);
2005         return er;
2006 }
2007
2008 enum emulation_result kvm_mips_emulate_tlbmod(unsigned long cause,
2009                                               uint32_t *opc,
2010                                               struct kvm_run *run,
2011                                               struct kvm_vcpu *vcpu)
2012 {
2013         struct mips_coproc *cop0 = vcpu->arch.cop0;
2014         unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
2015                         (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
2016         struct kvm_vcpu_arch *arch = &vcpu->arch;
2017
2018         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2019                 /* save old pc */
2020                 kvm_write_c0_guest_epc(cop0, arch->pc);
2021                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2022
2023                 if (cause & CAUSEF_BD)
2024                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2025                 else
2026                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2027
2028                 kvm_debug("[EXL == 0] Delivering TLB MOD @ pc %#lx\n",
2029                           arch->pc);
2030
2031                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2032         } else {
2033                 kvm_debug("[EXL == 1] Delivering TLB MOD @ pc %#lx\n",
2034                           arch->pc);
2035                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2036         }
2037
2038         kvm_change_c0_guest_cause(cop0, (0xff),
2039                                   (EXCCODE_MOD << CAUSEB_EXCCODE));
2040
2041         /* setup badvaddr, context and entryhi registers for the guest */
2042         kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2043         /* XXXKYMA: is the context register used by linux??? */
2044         kvm_write_c0_guest_entryhi(cop0, entryhi);
2045         /* Blow away the shadow host TLBs */
2046         kvm_mips_flush_host_tlb(1);
2047
2048         return EMULATE_DONE;
2049 }
2050
2051 enum emulation_result kvm_mips_emulate_fpu_exc(unsigned long cause,
2052                                                uint32_t *opc,
2053                                                struct kvm_run *run,
2054                                                struct kvm_vcpu *vcpu)
2055 {
2056         struct mips_coproc *cop0 = vcpu->arch.cop0;
2057         struct kvm_vcpu_arch *arch = &vcpu->arch;
2058
2059         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2060                 /* save old pc */
2061                 kvm_write_c0_guest_epc(cop0, arch->pc);
2062                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2063
2064                 if (cause & CAUSEF_BD)
2065                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2066                 else
2067                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2068
2069         }
2070
2071         arch->pc = KVM_GUEST_KSEG0 + 0x180;
2072
2073         kvm_change_c0_guest_cause(cop0, (0xff),
2074                                   (EXCCODE_CPU << CAUSEB_EXCCODE));
2075         kvm_change_c0_guest_cause(cop0, (CAUSEF_CE), (0x1 << CAUSEB_CE));
2076
2077         return EMULATE_DONE;
2078 }
2079
2080 enum emulation_result kvm_mips_emulate_ri_exc(unsigned long cause,
2081                                               uint32_t *opc,
2082                                               struct kvm_run *run,
2083                                               struct kvm_vcpu *vcpu)
2084 {
2085         struct mips_coproc *cop0 = vcpu->arch.cop0;
2086         struct kvm_vcpu_arch *arch = &vcpu->arch;
2087         enum emulation_result er = EMULATE_DONE;
2088
2089         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2090                 /* save old pc */
2091                 kvm_write_c0_guest_epc(cop0, arch->pc);
2092                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2093
2094                 if (cause & CAUSEF_BD)
2095                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2096                 else
2097                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2098
2099                 kvm_debug("Delivering RI @ pc %#lx\n", arch->pc);
2100
2101                 kvm_change_c0_guest_cause(cop0, (0xff),
2102                                           (EXCCODE_RI << CAUSEB_EXCCODE));
2103
2104                 /* Set PC to the exception entry point */
2105                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2106
2107         } else {
2108                 kvm_err("Trying to deliver RI when EXL is already set\n");
2109                 er = EMULATE_FAIL;
2110         }
2111
2112         return er;
2113 }
2114
2115 enum emulation_result kvm_mips_emulate_bp_exc(unsigned long cause,
2116                                               uint32_t *opc,
2117                                               struct kvm_run *run,
2118                                               struct kvm_vcpu *vcpu)
2119 {
2120         struct mips_coproc *cop0 = vcpu->arch.cop0;
2121         struct kvm_vcpu_arch *arch = &vcpu->arch;
2122         enum emulation_result er = EMULATE_DONE;
2123
2124         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2125                 /* save old pc */
2126                 kvm_write_c0_guest_epc(cop0, arch->pc);
2127                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2128
2129                 if (cause & CAUSEF_BD)
2130                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2131                 else
2132                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2133
2134                 kvm_debug("Delivering BP @ pc %#lx\n", arch->pc);
2135
2136                 kvm_change_c0_guest_cause(cop0, (0xff),
2137                                           (EXCCODE_BP << CAUSEB_EXCCODE));
2138
2139                 /* Set PC to the exception entry point */
2140                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2141
2142         } else {
2143                 kvm_err("Trying to deliver BP when EXL is already set\n");
2144                 er = EMULATE_FAIL;
2145         }
2146
2147         return er;
2148 }
2149
2150 enum emulation_result kvm_mips_emulate_trap_exc(unsigned long cause,
2151                                                 uint32_t *opc,
2152                                                 struct kvm_run *run,
2153                                                 struct kvm_vcpu *vcpu)
2154 {
2155         struct mips_coproc *cop0 = vcpu->arch.cop0;
2156         struct kvm_vcpu_arch *arch = &vcpu->arch;
2157         enum emulation_result er = EMULATE_DONE;
2158
2159         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2160                 /* save old pc */
2161                 kvm_write_c0_guest_epc(cop0, arch->pc);
2162                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2163
2164                 if (cause & CAUSEF_BD)
2165                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2166                 else
2167                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2168
2169                 kvm_debug("Delivering TRAP @ pc %#lx\n", arch->pc);
2170
2171                 kvm_change_c0_guest_cause(cop0, (0xff),
2172                                           (EXCCODE_TR << CAUSEB_EXCCODE));
2173
2174                 /* Set PC to the exception entry point */
2175                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2176
2177         } else {
2178                 kvm_err("Trying to deliver TRAP when EXL is already set\n");
2179                 er = EMULATE_FAIL;
2180         }
2181
2182         return er;
2183 }
2184
2185 enum emulation_result kvm_mips_emulate_msafpe_exc(unsigned long cause,
2186                                                   uint32_t *opc,
2187                                                   struct kvm_run *run,
2188                                                   struct kvm_vcpu *vcpu)
2189 {
2190         struct mips_coproc *cop0 = vcpu->arch.cop0;
2191         struct kvm_vcpu_arch *arch = &vcpu->arch;
2192         enum emulation_result er = EMULATE_DONE;
2193
2194         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2195                 /* save old pc */
2196                 kvm_write_c0_guest_epc(cop0, arch->pc);
2197                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2198
2199                 if (cause & CAUSEF_BD)
2200                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2201                 else
2202                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2203
2204                 kvm_debug("Delivering MSAFPE @ pc %#lx\n", arch->pc);
2205
2206                 kvm_change_c0_guest_cause(cop0, (0xff),
2207                                           (EXCCODE_MSAFPE << CAUSEB_EXCCODE));
2208
2209                 /* Set PC to the exception entry point */
2210                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2211
2212         } else {
2213                 kvm_err("Trying to deliver MSAFPE when EXL is already set\n");
2214                 er = EMULATE_FAIL;
2215         }
2216
2217         return er;
2218 }
2219
2220 enum emulation_result kvm_mips_emulate_fpe_exc(unsigned long cause,
2221                                                uint32_t *opc,
2222                                                struct kvm_run *run,
2223                                                struct kvm_vcpu *vcpu)
2224 {
2225         struct mips_coproc *cop0 = vcpu->arch.cop0;
2226         struct kvm_vcpu_arch *arch = &vcpu->arch;
2227         enum emulation_result er = EMULATE_DONE;
2228
2229         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2230                 /* save old pc */
2231                 kvm_write_c0_guest_epc(cop0, arch->pc);
2232                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2233
2234                 if (cause & CAUSEF_BD)
2235                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2236                 else
2237                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2238
2239                 kvm_debug("Delivering FPE @ pc %#lx\n", arch->pc);
2240
2241                 kvm_change_c0_guest_cause(cop0, (0xff),
2242                                           (EXCCODE_FPE << CAUSEB_EXCCODE));
2243
2244                 /* Set PC to the exception entry point */
2245                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2246
2247         } else {
2248                 kvm_err("Trying to deliver FPE when EXL is already set\n");
2249                 er = EMULATE_FAIL;
2250         }
2251
2252         return er;
2253 }
2254
2255 enum emulation_result kvm_mips_emulate_msadis_exc(unsigned long cause,
2256                                                   uint32_t *opc,
2257                                                   struct kvm_run *run,
2258                                                   struct kvm_vcpu *vcpu)
2259 {
2260         struct mips_coproc *cop0 = vcpu->arch.cop0;
2261         struct kvm_vcpu_arch *arch = &vcpu->arch;
2262         enum emulation_result er = EMULATE_DONE;
2263
2264         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2265                 /* save old pc */
2266                 kvm_write_c0_guest_epc(cop0, arch->pc);
2267                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2268
2269                 if (cause & CAUSEF_BD)
2270                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2271                 else
2272                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2273
2274                 kvm_debug("Delivering MSADIS @ pc %#lx\n", arch->pc);
2275
2276                 kvm_change_c0_guest_cause(cop0, (0xff),
2277                                           (EXCCODE_MSADIS << CAUSEB_EXCCODE));
2278
2279                 /* Set PC to the exception entry point */
2280                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2281
2282         } else {
2283                 kvm_err("Trying to deliver MSADIS when EXL is already set\n");
2284                 er = EMULATE_FAIL;
2285         }
2286
2287         return er;
2288 }
2289
2290 /* ll/sc, rdhwr, sync emulation */
2291
2292 #define OPCODE 0xfc000000
2293 #define BASE   0x03e00000
2294 #define RT     0x001f0000
2295 #define OFFSET 0x0000ffff
2296 #define LL     0xc0000000
2297 #define SC     0xe0000000
2298 #define SPEC0  0x00000000
2299 #define SPEC3  0x7c000000
2300 #define RD     0x0000f800
2301 #define FUNC   0x0000003f
2302 #define SYNC   0x0000000f
2303 #define RDHWR  0x0000003b
2304
2305 enum emulation_result kvm_mips_handle_ri(unsigned long cause, uint32_t *opc,
2306                                          struct kvm_run *run,
2307                                          struct kvm_vcpu *vcpu)
2308 {
2309         struct mips_coproc *cop0 = vcpu->arch.cop0;
2310         struct kvm_vcpu_arch *arch = &vcpu->arch;
2311         enum emulation_result er = EMULATE_DONE;
2312         unsigned long curr_pc;
2313         uint32_t inst;
2314
2315         /*
2316          * Update PC and hold onto current PC in case there is
2317          * an error and we want to rollback the PC
2318          */
2319         curr_pc = vcpu->arch.pc;
2320         er = update_pc(vcpu, cause);
2321         if (er == EMULATE_FAIL)
2322                 return er;
2323
2324         /* Fetch the instruction. */
2325         if (cause & CAUSEF_BD)
2326                 opc += 1;
2327
2328         inst = kvm_get_inst(opc, vcpu);
2329
2330         if (inst == KVM_INVALID_INST) {
2331                 kvm_err("%s: Cannot get inst @ %p\n", __func__, opc);
2332                 return EMULATE_FAIL;
2333         }
2334
2335         if ((inst & OPCODE) == SPEC3 && (inst & FUNC) == RDHWR) {
2336                 int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
2337                 int rd = (inst & RD) >> 11;
2338                 int rt = (inst & RT) >> 16;
2339                 /* If usermode, check RDHWR rd is allowed by guest HWREna */
2340                 if (usermode && !(kvm_read_c0_guest_hwrena(cop0) & BIT(rd))) {
2341                         kvm_debug("RDHWR %#x disallowed by HWREna @ %p\n",
2342                                   rd, opc);
2343                         goto emulate_ri;
2344                 }
2345                 switch (rd) {
2346                 case 0: /* CPU number */
2347                         arch->gprs[rt] = 0;
2348                         break;
2349                 case 1: /* SYNCI length */
2350                         arch->gprs[rt] = min(current_cpu_data.dcache.linesz,
2351                                              current_cpu_data.icache.linesz);
2352                         break;
2353                 case 2: /* Read count register */
2354                         arch->gprs[rt] = kvm_mips_read_count(vcpu);
2355                         break;
2356                 case 3: /* Count register resolution */
2357                         switch (current_cpu_data.cputype) {
2358                         case CPU_20KC:
2359                         case CPU_25KF:
2360                                 arch->gprs[rt] = 1;
2361                                 break;
2362                         default:
2363                                 arch->gprs[rt] = 2;
2364                         }
2365                         break;
2366                 case 29:
2367                         arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0);
2368                         break;
2369
2370                 default:
2371                         kvm_debug("RDHWR %#x not supported @ %p\n", rd, opc);
2372                         goto emulate_ri;
2373                 }
2374         } else {
2375                 kvm_debug("Emulate RI not supported @ %p: %#x\n", opc, inst);
2376                 goto emulate_ri;
2377         }
2378
2379         return EMULATE_DONE;
2380
2381 emulate_ri:
2382         /*
2383          * Rollback PC (if in branch delay slot then the PC already points to
2384          * branch target), and pass the RI exception to the guest OS.
2385          */
2386         vcpu->arch.pc = curr_pc;
2387         return kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
2388 }
2389
2390 enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu,
2391                                                   struct kvm_run *run)
2392 {
2393         unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
2394         enum emulation_result er = EMULATE_DONE;
2395
2396         if (run->mmio.len > sizeof(*gpr)) {
2397                 kvm_err("Bad MMIO length: %d", run->mmio.len);
2398                 er = EMULATE_FAIL;
2399                 goto done;
2400         }
2401
2402         er = update_pc(vcpu, vcpu->arch.pending_load_cause);
2403         if (er == EMULATE_FAIL)
2404                 return er;
2405
2406         switch (run->mmio.len) {
2407         case 4:
2408                 *gpr = *(int32_t *) run->mmio.data;
2409                 break;
2410
2411         case 2:
2412                 if (vcpu->mmio_needed == 2)
2413                         *gpr = *(int16_t *) run->mmio.data;
2414                 else
2415                         *gpr = *(uint16_t *)run->mmio.data;
2416
2417                 break;
2418         case 1:
2419                 if (vcpu->mmio_needed == 2)
2420                         *gpr = *(int8_t *) run->mmio.data;
2421                 else
2422                         *gpr = *(u8 *) run->mmio.data;
2423                 break;
2424         }
2425
2426         if (vcpu->arch.pending_load_cause & CAUSEF_BD)
2427                 kvm_debug("[%#lx] Completing %d byte BD Load to gpr %d (0x%08lx) type %d\n",
2428                           vcpu->arch.pc, run->mmio.len, vcpu->arch.io_gpr, *gpr,
2429                           vcpu->mmio_needed);
2430
2431 done:
2432         return er;
2433 }
2434
2435 static enum emulation_result kvm_mips_emulate_exc(unsigned long cause,
2436                                                   uint32_t *opc,
2437                                                   struct kvm_run *run,
2438                                                   struct kvm_vcpu *vcpu)
2439 {
2440         uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2441         struct mips_coproc *cop0 = vcpu->arch.cop0;
2442         struct kvm_vcpu_arch *arch = &vcpu->arch;
2443         enum emulation_result er = EMULATE_DONE;
2444
2445         if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
2446                 /* save old pc */
2447                 kvm_write_c0_guest_epc(cop0, arch->pc);
2448                 kvm_set_c0_guest_status(cop0, ST0_EXL);
2449
2450                 if (cause & CAUSEF_BD)
2451                         kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
2452                 else
2453                         kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
2454
2455                 kvm_change_c0_guest_cause(cop0, (0xff),
2456                                           (exccode << CAUSEB_EXCCODE));
2457
2458                 /* Set PC to the exception entry point */
2459                 arch->pc = KVM_GUEST_KSEG0 + 0x180;
2460                 kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
2461
2462                 kvm_debug("Delivering EXC %d @ pc %#lx, badVaddr: %#lx\n",
2463                           exccode, kvm_read_c0_guest_epc(cop0),
2464                           kvm_read_c0_guest_badvaddr(cop0));
2465         } else {
2466                 kvm_err("Trying to deliver EXC when EXL is already set\n");
2467                 er = EMULATE_FAIL;
2468         }
2469
2470         return er;
2471 }
2472
2473 enum emulation_result kvm_mips_check_privilege(unsigned long cause,
2474                                                uint32_t *opc,
2475                                                struct kvm_run *run,
2476                                                struct kvm_vcpu *vcpu)
2477 {
2478         enum emulation_result er = EMULATE_DONE;
2479         uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2480         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
2481
2482         int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
2483
2484         if (usermode) {
2485                 switch (exccode) {
2486                 case EXCCODE_INT:
2487                 case EXCCODE_SYS:
2488                 case EXCCODE_BP:
2489                 case EXCCODE_RI:
2490                 case EXCCODE_TR:
2491                 case EXCCODE_MSAFPE:
2492                 case EXCCODE_FPE:
2493                 case EXCCODE_MSADIS:
2494                         break;
2495
2496                 case EXCCODE_CPU:
2497                         if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 0)
2498                                 er = EMULATE_PRIV_FAIL;
2499                         break;
2500
2501                 case EXCCODE_MOD:
2502                         break;
2503
2504                 case EXCCODE_TLBL:
2505                         /*
2506                          * We we are accessing Guest kernel space, then send an
2507                          * address error exception to the guest
2508                          */
2509                         if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
2510                                 kvm_debug("%s: LD MISS @ %#lx\n", __func__,
2511                                           badvaddr);
2512                                 cause &= ~0xff;
2513                                 cause |= (EXCCODE_ADEL << CAUSEB_EXCCODE);
2514                                 er = EMULATE_PRIV_FAIL;
2515                         }
2516                         break;
2517
2518                 case EXCCODE_TLBS:
2519                         /*
2520                          * We we are accessing Guest kernel space, then send an
2521                          * address error exception to the guest
2522                          */
2523                         if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
2524                                 kvm_debug("%s: ST MISS @ %#lx\n", __func__,
2525                                           badvaddr);
2526                                 cause &= ~0xff;
2527                                 cause |= (EXCCODE_ADES << CAUSEB_EXCCODE);
2528                                 er = EMULATE_PRIV_FAIL;
2529                         }
2530                         break;
2531
2532                 case EXCCODE_ADES:
2533                         kvm_debug("%s: address error ST @ %#lx\n", __func__,
2534                                   badvaddr);
2535                         if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
2536                                 cause &= ~0xff;
2537                                 cause |= (EXCCODE_TLBS << CAUSEB_EXCCODE);
2538                         }
2539                         er = EMULATE_PRIV_FAIL;
2540                         break;
2541                 case EXCCODE_ADEL:
2542                         kvm_debug("%s: address error LD @ %#lx\n", __func__,
2543                                   badvaddr);
2544                         if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
2545                                 cause &= ~0xff;
2546                                 cause |= (EXCCODE_TLBL << CAUSEB_EXCCODE);
2547                         }
2548                         er = EMULATE_PRIV_FAIL;
2549                         break;
2550                 default:
2551                         er = EMULATE_PRIV_FAIL;
2552                         break;
2553                 }
2554         }
2555
2556         if (er == EMULATE_PRIV_FAIL)
2557                 kvm_mips_emulate_exc(cause, opc, run, vcpu);
2558
2559         return er;
2560 }
2561
2562 /*
2563  * User Address (UA) fault, this could happen if
2564  * (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this
2565  *     case we pass on the fault to the guest kernel and let it handle it.
2566  * (2) TLB entry is present in the Guest TLB but not in the shadow, in this
2567  *     case we inject the TLB from the Guest TLB into the shadow host TLB
2568  */
2569 enum emulation_result kvm_mips_handle_tlbmiss(unsigned long cause,
2570                                               uint32_t *opc,
2571                                               struct kvm_run *run,
2572                                               struct kvm_vcpu *vcpu)
2573 {
2574         enum emulation_result er = EMULATE_DONE;
2575         uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
2576         unsigned long va = vcpu->arch.host_cp0_badvaddr;
2577         int index;
2578
2579         kvm_debug("kvm_mips_handle_tlbmiss: badvaddr: %#lx, entryhi: %#lx\n",
2580                   vcpu->arch.host_cp0_badvaddr, vcpu->arch.host_cp0_entryhi);
2581
2582         /*
2583          * KVM would not have got the exception if this entry was valid in the
2584          * shadow host TLB. Check the Guest TLB, if the entry is not there then
2585          * send the guest an exception. The guest exc handler should then inject
2586          * an entry into the guest TLB.
2587          */
2588         index = kvm_mips_guest_tlb_lookup(vcpu,
2589                       (va & VPN2_MASK) |
2590                       (kvm_read_c0_guest_entryhi(vcpu->arch.cop0) &
2591                        KVM_ENTRYHI_ASID));
2592         if (index < 0) {
2593                 if (exccode == EXCCODE_TLBL) {
2594                         er = kvm_mips_emulate_tlbmiss_ld(cause, opc, run, vcpu);
2595                 } else if (exccode == EXCCODE_TLBS) {
2596                         er = kvm_mips_emulate_tlbmiss_st(cause, opc, run, vcpu);
2597                 } else {
2598                         kvm_err("%s: invalid exc code: %d\n", __func__,
2599                                 exccode);
2600                         er = EMULATE_FAIL;
2601                 }
2602         } else {
2603                 struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
2604
2605                 /*
2606                  * Check if the entry is valid, if not then setup a TLB invalid
2607                  * exception to the guest
2608                  */
2609                 if (!TLB_IS_VALID(*tlb, va)) {
2610                         if (exccode == EXCCODE_TLBL) {
2611                                 er = kvm_mips_emulate_tlbinv_ld(cause, opc, run,
2612                                                                 vcpu);
2613                         } else if (exccode == EXCCODE_TLBS) {
2614                                 er = kvm_mips_emulate_tlbinv_st(cause, opc, run,
2615                                                                 vcpu);
2616                         } else {
2617                                 kvm_err("%s: invalid exc code: %d\n", __func__,
2618                                         exccode);
2619                                 er = EMULATE_FAIL;
2620                         }
2621                 } else {
2622                         kvm_debug("Injecting hi: %#lx, lo0: %#lx, lo1: %#lx into shadow host TLB\n",
2623                                   tlb->tlb_hi, tlb->tlb_lo0, tlb->tlb_lo1);
2624                         /*
2625                          * OK we have a Guest TLB entry, now inject it into the
2626                          * shadow host TLB
2627                          */
2628                         kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, NULL,
2629                                                              NULL);
2630                 }
2631         }
2632
2633         return er;
2634 }