linux/arch/mips/kvm/kvm_mips_emul.c
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   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/kvm_host.h>
  15#include <linux/module.h>
  16#include <linux/vmalloc.h>
  17#include <linux/fs.h>
  18#include <linux/bootmem.h>
  19#include <linux/random.h>
  20#include <asm/page.h>
  21#include <asm/cacheflush.h>
  22#include <asm/cpu-info.h>
  23#include <asm/mmu_context.h>
  24#include <asm/tlbflush.h>
  25#include <asm/inst.h>
  26
  27#undef CONFIG_MIPS_MT
  28#include <asm/r4kcache.h>
  29#define CONFIG_MIPS_MT
  30
  31#include "kvm_mips_opcode.h"
  32#include "kvm_mips_int.h"
  33#include "kvm_mips_comm.h"
  34
  35#include "trace.h"
  36
  37/*
  38 * Compute the return address and do emulate branch simulation, if required.
  39 * This function should be called only in branch delay slot active.
  40 */
  41unsigned long kvm_compute_return_epc(struct kvm_vcpu *vcpu,
  42        unsigned long instpc)
  43{
  44        unsigned int dspcontrol;
  45        union mips_instruction insn;
  46        struct kvm_vcpu_arch *arch = &vcpu->arch;
  47        long epc = instpc;
  48        long nextpc = KVM_INVALID_INST;
  49
  50        if (epc & 3)
  51                goto unaligned;
  52
  53        /*
  54         * Read the instruction
  55         */
  56        insn.word = kvm_get_inst((uint32_t *) epc, vcpu);
  57
  58        if (insn.word == KVM_INVALID_INST)
  59                return KVM_INVALID_INST;
  60
  61        switch (insn.i_format.opcode) {
  62                /*
  63                 * jr and jalr are in r_format format.
  64                 */
  65        case spec_op:
  66                switch (insn.r_format.func) {
  67                case jalr_op:
  68                        arch->gprs[insn.r_format.rd] = epc + 8;
  69                        /* Fall through */
  70                case jr_op:
  71                        nextpc = arch->gprs[insn.r_format.rs];
  72                        break;
  73                }
  74                break;
  75
  76                /*
  77                 * This group contains:
  78                 * bltz_op, bgez_op, bltzl_op, bgezl_op,
  79                 * bltzal_op, bgezal_op, bltzall_op, bgezall_op.
  80                 */
  81        case bcond_op:
  82                switch (insn.i_format.rt) {
  83                case bltz_op:
  84                case bltzl_op:
  85                        if ((long)arch->gprs[insn.i_format.rs] < 0)
  86                                epc = epc + 4 + (insn.i_format.simmediate << 2);
  87                        else
  88                                epc += 8;
  89                        nextpc = epc;
  90                        break;
  91
  92                case bgez_op:
  93                case bgezl_op:
  94                        if ((long)arch->gprs[insn.i_format.rs] >= 0)
  95                                epc = epc + 4 + (insn.i_format.simmediate << 2);
  96                        else
  97                                epc += 8;
  98                        nextpc = epc;
  99                        break;
 100
 101                case bltzal_op:
 102                case bltzall_op:
 103                        arch->gprs[31] = epc + 8;
 104                        if ((long)arch->gprs[insn.i_format.rs] < 0)
 105                                epc = epc + 4 + (insn.i_format.simmediate << 2);
 106                        else
 107                                epc += 8;
 108                        nextpc = epc;
 109                        break;
 110
 111                case bgezal_op:
 112                case bgezall_op:
 113                        arch->gprs[31] = epc + 8;
 114                        if ((long)arch->gprs[insn.i_format.rs] >= 0)
 115                                epc = epc + 4 + (insn.i_format.simmediate << 2);
 116                        else
 117                                epc += 8;
 118                        nextpc = epc;
 119                        break;
 120                case bposge32_op:
 121                        if (!cpu_has_dsp)
 122                                goto sigill;
 123
 124                        dspcontrol = rddsp(0x01);
 125
 126                        if (dspcontrol >= 32) {
 127                                epc = epc + 4 + (insn.i_format.simmediate << 2);
 128                        } else
 129                                epc += 8;
 130                        nextpc = epc;
 131                        break;
 132                }
 133                break;
 134
 135                /*
 136                 * These are unconditional and in j_format.
 137                 */
 138        case jal_op:
 139                arch->gprs[31] = instpc + 8;
 140        case j_op:
 141                epc += 4;
 142                epc >>= 28;
 143                epc <<= 28;
 144                epc |= (insn.j_format.target << 2);
 145                nextpc = epc;
 146                break;
 147
 148                /*
 149                 * These are conditional and in i_format.
 150                 */
 151        case beq_op:
 152        case beql_op:
 153                if (arch->gprs[insn.i_format.rs] ==
 154                    arch->gprs[insn.i_format.rt])
 155                        epc = epc + 4 + (insn.i_format.simmediate << 2);
 156                else
 157                        epc += 8;
 158                nextpc = epc;
 159                break;
 160
 161        case bne_op:
 162        case bnel_op:
 163                if (arch->gprs[insn.i_format.rs] !=
 164                    arch->gprs[insn.i_format.rt])
 165                        epc = epc + 4 + (insn.i_format.simmediate << 2);
 166                else
 167                        epc += 8;
 168                nextpc = epc;
 169                break;
 170
 171        case blez_op:           /* not really i_format */
 172        case blezl_op:
 173                /* rt field assumed to be zero */
 174                if ((long)arch->gprs[insn.i_format.rs] <= 0)
 175                        epc = epc + 4 + (insn.i_format.simmediate << 2);
 176                else
 177                        epc += 8;
 178                nextpc = epc;
 179                break;
 180
 181        case bgtz_op:
 182        case bgtzl_op:
 183                /* rt field assumed to be zero */
 184                if ((long)arch->gprs[insn.i_format.rs] > 0)
 185                        epc = epc + 4 + (insn.i_format.simmediate << 2);
 186                else
 187                        epc += 8;
 188                nextpc = epc;
 189                break;
 190
 191                /*
 192                 * And now the FPA/cp1 branch instructions.
 193                 */
 194        case cop1_op:
 195                printk("%s: unsupported cop1_op\n", __func__);
 196                break;
 197        }
 198
 199        return nextpc;
 200
 201unaligned:
 202        printk("%s: unaligned epc\n", __func__);
 203        return nextpc;
 204
 205sigill:
 206        printk("%s: DSP branch but not DSP ASE\n", __func__);
 207        return nextpc;
 208}
 209
 210enum emulation_result update_pc(struct kvm_vcpu *vcpu, uint32_t cause)
 211{
 212        unsigned long branch_pc;
 213        enum emulation_result er = EMULATE_DONE;
 214
 215        if (cause & CAUSEF_BD) {
 216                branch_pc = kvm_compute_return_epc(vcpu, vcpu->arch.pc);
 217                if (branch_pc == KVM_INVALID_INST) {
 218                        er = EMULATE_FAIL;
 219                } else {
 220                        vcpu->arch.pc = branch_pc;
 221                        kvm_debug("BD update_pc(): New PC: %#lx\n", vcpu->arch.pc);
 222                }
 223        } else
 224                vcpu->arch.pc += 4;
 225
 226        kvm_debug("update_pc(): New PC: %#lx\n", vcpu->arch.pc);
 227
 228        return er;
 229}
 230
 231/* Everytime the compare register is written to, we need to decide when to fire
 232 * the timer that represents timer ticks to the GUEST.
 233 *
 234 */
 235enum emulation_result kvm_mips_emulate_count(struct kvm_vcpu *vcpu)
 236{
 237        struct mips_coproc *cop0 = vcpu->arch.cop0;
 238        enum emulation_result er = EMULATE_DONE;
 239
 240        /* If COUNT is enabled */
 241        if (!(kvm_read_c0_guest_cause(cop0) & CAUSEF_DC)) {
 242                hrtimer_try_to_cancel(&vcpu->arch.comparecount_timer);
 243                hrtimer_start(&vcpu->arch.comparecount_timer,
 244                              ktime_set(0, MS_TO_NS(10)), HRTIMER_MODE_REL);
 245        } else {
 246                hrtimer_try_to_cancel(&vcpu->arch.comparecount_timer);
 247        }
 248
 249        return er;
 250}
 251
 252enum emulation_result kvm_mips_emul_eret(struct kvm_vcpu *vcpu)
 253{
 254        struct mips_coproc *cop0 = vcpu->arch.cop0;
 255        enum emulation_result er = EMULATE_DONE;
 256
 257        if (kvm_read_c0_guest_status(cop0) & ST0_EXL) {
 258                kvm_debug("[%#lx] ERET to %#lx\n", vcpu->arch.pc,
 259                          kvm_read_c0_guest_epc(cop0));
 260                kvm_clear_c0_guest_status(cop0, ST0_EXL);
 261                vcpu->arch.pc = kvm_read_c0_guest_epc(cop0);
 262
 263        } else if (kvm_read_c0_guest_status(cop0) & ST0_ERL) {
 264                kvm_clear_c0_guest_status(cop0, ST0_ERL);
 265                vcpu->arch.pc = kvm_read_c0_guest_errorepc(cop0);
 266        } else {
 267                printk("[%#lx] ERET when MIPS_SR_EXL|MIPS_SR_ERL == 0\n",
 268                       vcpu->arch.pc);
 269                er = EMULATE_FAIL;
 270        }
 271
 272        return er;
 273}
 274
 275enum emulation_result kvm_mips_emul_wait(struct kvm_vcpu *vcpu)
 276{
 277        enum emulation_result er = EMULATE_DONE;
 278
 279        kvm_debug("[%#lx] !!!WAIT!!! (%#lx)\n", vcpu->arch.pc,
 280                  vcpu->arch.pending_exceptions);
 281
 282        ++vcpu->stat.wait_exits;
 283        trace_kvm_exit(vcpu, WAIT_EXITS);
 284        if (!vcpu->arch.pending_exceptions) {
 285                vcpu->arch.wait = 1;
 286                kvm_vcpu_block(vcpu);
 287
 288                /* We we are runnable, then definitely go off to user space to check if any
 289                 * I/O interrupts are pending.
 290                 */
 291                if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
 292                        clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
 293                        vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
 294                }
 295        }
 296
 297        return er;
 298}
 299
 300/* XXXKYMA: Linux doesn't seem to use TLBR, return EMULATE_FAIL for now so that we can catch
 301 * this, if things ever change
 302 */
 303enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu)
 304{
 305        struct mips_coproc *cop0 = vcpu->arch.cop0;
 306        enum emulation_result er = EMULATE_FAIL;
 307        uint32_t pc = vcpu->arch.pc;
 308
 309        printk("[%#x] COP0_TLBR [%ld]\n", pc, kvm_read_c0_guest_index(cop0));
 310        return er;
 311}
 312
 313/* Write Guest TLB Entry @ Index */
 314enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu)
 315{
 316        struct mips_coproc *cop0 = vcpu->arch.cop0;
 317        int index = kvm_read_c0_guest_index(cop0);
 318        enum emulation_result er = EMULATE_DONE;
 319        struct kvm_mips_tlb *tlb = NULL;
 320        uint32_t pc = vcpu->arch.pc;
 321
 322        if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) {
 323                printk("%s: illegal index: %d\n", __func__, index);
 324                printk
 325                    ("[%#x] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
 326                     pc, index, kvm_read_c0_guest_entryhi(cop0),
 327                     kvm_read_c0_guest_entrylo0(cop0),
 328                     kvm_read_c0_guest_entrylo1(cop0),
 329                     kvm_read_c0_guest_pagemask(cop0));
 330                index = (index & ~0x80000000) % KVM_MIPS_GUEST_TLB_SIZE;
 331        }
 332
 333        tlb = &vcpu->arch.guest_tlb[index];
 334#if 1
 335        /* Probe the shadow host TLB for the entry being overwritten, if one matches, invalidate it */
 336        kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
 337#endif
 338
 339        tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
 340        tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
 341        tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0);
 342        tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0);
 343
 344        kvm_debug
 345            ("[%#x] COP0_TLBWI [%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx, mask: %#lx)\n",
 346             pc, index, kvm_read_c0_guest_entryhi(cop0),
 347             kvm_read_c0_guest_entrylo0(cop0), kvm_read_c0_guest_entrylo1(cop0),
 348             kvm_read_c0_guest_pagemask(cop0));
 349
 350        return er;
 351}
 352
 353/* Write Guest TLB Entry @ Random Index */
 354enum emulation_result kvm_mips_emul_tlbwr(struct kvm_vcpu *vcpu)
 355{
 356        struct mips_coproc *cop0 = vcpu->arch.cop0;
 357        enum emulation_result er = EMULATE_DONE;
 358        struct kvm_mips_tlb *tlb = NULL;
 359        uint32_t pc = vcpu->arch.pc;
 360        int index;
 361
 362#if 1
 363        get_random_bytes(&index, sizeof(index));
 364        index &= (KVM_MIPS_GUEST_TLB_SIZE - 1);
 365#else
 366        index = jiffies % KVM_MIPS_GUEST_TLB_SIZE;
 367#endif
 368
 369        if (index < 0 || index >= KVM_MIPS_GUEST_TLB_SIZE) {
 370                printk("%s: illegal index: %d\n", __func__, index);
 371                return EMULATE_FAIL;
 372        }
 373
 374        tlb = &vcpu->arch.guest_tlb[index];
 375
 376#if 1
 377        /* Probe the shadow host TLB for the entry being overwritten, if one matches, invalidate it */
 378        kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
 379#endif
 380
 381        tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
 382        tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
 383        tlb->tlb_lo0 = kvm_read_c0_guest_entrylo0(cop0);
 384        tlb->tlb_lo1 = kvm_read_c0_guest_entrylo1(cop0);
 385
 386        kvm_debug
 387            ("[%#x] COP0_TLBWR[%d] (entryhi: %#lx, entrylo0: %#lx entrylo1: %#lx)\n",
 388             pc, index, kvm_read_c0_guest_entryhi(cop0),
 389             kvm_read_c0_guest_entrylo0(cop0),
 390             kvm_read_c0_guest_entrylo1(cop0));
 391
 392        return er;
 393}
 394
 395enum emulation_result kvm_mips_emul_tlbp(struct kvm_vcpu *vcpu)
 396{
 397        struct mips_coproc *cop0 = vcpu->arch.cop0;
 398        long entryhi = kvm_read_c0_guest_entryhi(cop0);
 399        enum emulation_result er = EMULATE_DONE;
 400        uint32_t pc = vcpu->arch.pc;
 401        int index = -1;
 402
 403        index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
 404
 405        kvm_write_c0_guest_index(cop0, index);
 406
 407        kvm_debug("[%#x] COP0_TLBP (entryhi: %#lx), index: %d\n", pc, entryhi,
 408                  index);
 409
 410        return er;
 411}
 412
 413enum emulation_result
 414kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc, uint32_t cause,
 415                     struct kvm_run *run, struct kvm_vcpu *vcpu)
 416{
 417        struct mips_coproc *cop0 = vcpu->arch.cop0;
 418        enum emulation_result er = EMULATE_DONE;
 419        int32_t rt, rd, copz, sel, co_bit, op;
 420        uint32_t pc = vcpu->arch.pc;
 421        unsigned long curr_pc;
 422
 423        /*
 424         * Update PC and hold onto current PC in case there is
 425         * an error and we want to rollback the PC
 426         */
 427        curr_pc = vcpu->arch.pc;
 428        er = update_pc(vcpu, cause);
 429        if (er == EMULATE_FAIL) {
 430                return er;
 431        }
 432
 433        copz = (inst >> 21) & 0x1f;
 434        rt = (inst >> 16) & 0x1f;
 435        rd = (inst >> 11) & 0x1f;
 436        sel = inst & 0x7;
 437        co_bit = (inst >> 25) & 1;
 438
 439        /* Verify that the register is valid */
 440        if (rd > MIPS_CP0_DESAVE) {
 441                printk("Invalid rd: %d\n", rd);
 442                er = EMULATE_FAIL;
 443                goto done;
 444        }
 445
 446        if (co_bit) {
 447                op = (inst) & 0xff;
 448
 449                switch (op) {
 450                case tlbr_op:   /*  Read indexed TLB entry  */
 451                        er = kvm_mips_emul_tlbr(vcpu);
 452                        break;
 453                case tlbwi_op:  /*  Write indexed  */
 454                        er = kvm_mips_emul_tlbwi(vcpu);
 455                        break;
 456                case tlbwr_op:  /*  Write random  */
 457                        er = kvm_mips_emul_tlbwr(vcpu);
 458                        break;
 459                case tlbp_op:   /* TLB Probe */
 460                        er = kvm_mips_emul_tlbp(vcpu);
 461                        break;
 462                case rfe_op:
 463                        printk("!!!COP0_RFE!!!\n");
 464                        break;
 465                case eret_op:
 466                        er = kvm_mips_emul_eret(vcpu);
 467                        goto dont_update_pc;
 468                        break;
 469                case wait_op:
 470                        er = kvm_mips_emul_wait(vcpu);
 471                        break;
 472                }
 473        } else {
 474                switch (copz) {
 475                case mfc_op:
 476#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
 477                        cop0->stat[rd][sel]++;
 478#endif
 479                        /* Get reg */
 480                        if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
 481                                /* XXXKYMA: Run the Guest count register @ 1/4 the rate of the host */
 482                                vcpu->arch.gprs[rt] = (read_c0_count() >> 2);
 483                        } else if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) {
 484                                vcpu->arch.gprs[rt] = 0x0;
 485#ifdef CONFIG_KVM_MIPS_DYN_TRANS
 486                                kvm_mips_trans_mfc0(inst, opc, vcpu);
 487#endif
 488                        }
 489                        else {
 490                                vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
 491
 492#ifdef CONFIG_KVM_MIPS_DYN_TRANS
 493                                kvm_mips_trans_mfc0(inst, opc, vcpu);
 494#endif
 495                        }
 496
 497                        kvm_debug
 498                            ("[%#x] MFCz[%d][%d], vcpu->arch.gprs[%d]: %#lx\n",
 499                             pc, rd, sel, rt, vcpu->arch.gprs[rt]);
 500
 501                        break;
 502
 503                case dmfc_op:
 504                        vcpu->arch.gprs[rt] = cop0->reg[rd][sel];
 505                        break;
 506
 507                case mtc_op:
 508#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
 509                        cop0->stat[rd][sel]++;
 510#endif
 511                        if ((rd == MIPS_CP0_TLB_INDEX)
 512                            && (vcpu->arch.gprs[rt] >=
 513                                KVM_MIPS_GUEST_TLB_SIZE)) {
 514                                printk("Invalid TLB Index: %ld",
 515                                       vcpu->arch.gprs[rt]);
 516                                er = EMULATE_FAIL;
 517                                break;
 518                        }
 519#define C0_EBASE_CORE_MASK 0xff
 520                        if ((rd == MIPS_CP0_PRID) && (sel == 1)) {
 521                                /* Preserve CORE number */
 522                                kvm_change_c0_guest_ebase(cop0,
 523                                                          ~(C0_EBASE_CORE_MASK),
 524                                                          vcpu->arch.gprs[rt]);
 525                                printk("MTCz, cop0->reg[EBASE]: %#lx\n",
 526                                       kvm_read_c0_guest_ebase(cop0));
 527                        } else if (rd == MIPS_CP0_TLB_HI && sel == 0) {
 528                                uint32_t nasid =
 529                                    vcpu->arch.gprs[rt] & ASID_MASK;
 530                                if ((KSEGX(vcpu->arch.gprs[rt]) != CKSEG0)
 531                                    &&
 532                                    ((kvm_read_c0_guest_entryhi(cop0) &
 533                                      ASID_MASK) != nasid)) {
 534
 535                                        kvm_debug
 536                                            ("MTCz, change ASID from %#lx to %#lx\n",
 537                                             kvm_read_c0_guest_entryhi(cop0) &
 538                                             ASID_MASK,
 539                                             vcpu->arch.gprs[rt] & ASID_MASK);
 540
 541                                        /* Blow away the shadow host TLBs */
 542                                        kvm_mips_flush_host_tlb(1);
 543                                }
 544                                kvm_write_c0_guest_entryhi(cop0,
 545                                                           vcpu->arch.gprs[rt]);
 546                        }
 547                        /* Are we writing to COUNT */
 548                        else if ((rd == MIPS_CP0_COUNT) && (sel == 0)) {
 549                                /* Linux doesn't seem to write into COUNT, we throw an error
 550                                 * if we notice a write to COUNT
 551                                 */
 552                                /*er = EMULATE_FAIL; */
 553                                goto done;
 554                        } else if ((rd == MIPS_CP0_COMPARE) && (sel == 0)) {
 555                                kvm_debug("[%#x] MTCz, COMPARE %#lx <- %#lx\n",
 556                                          pc, kvm_read_c0_guest_compare(cop0),
 557                                          vcpu->arch.gprs[rt]);
 558
 559                                /* If we are writing to COMPARE */
 560                                /* Clear pending timer interrupt, if any */
 561                                kvm_mips_callbacks->dequeue_timer_int(vcpu);
 562                                kvm_write_c0_guest_compare(cop0,
 563                                                           vcpu->arch.gprs[rt]);
 564                        } else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) {
 565                                kvm_write_c0_guest_status(cop0,
 566                                                          vcpu->arch.gprs[rt]);
 567                                /* Make sure that CU1 and NMI bits are never set */
 568                                kvm_clear_c0_guest_status(cop0,
 569                                                          (ST0_CU1 | ST0_NMI));
 570
 571#ifdef CONFIG_KVM_MIPS_DYN_TRANS
 572                                kvm_mips_trans_mtc0(inst, opc, vcpu);
 573#endif
 574                        } else {
 575                                cop0->reg[rd][sel] = vcpu->arch.gprs[rt];
 576#ifdef CONFIG_KVM_MIPS_DYN_TRANS
 577                                kvm_mips_trans_mtc0(inst, opc, vcpu);
 578#endif
 579                        }
 580
 581                        kvm_debug("[%#x] MTCz, cop0->reg[%d][%d]: %#lx\n", pc,
 582                                  rd, sel, cop0->reg[rd][sel]);
 583                        break;
 584
 585                case dmtc_op:
 586                        printk
 587                            ("!!!!!!![%#lx]dmtc_op: rt: %d, rd: %d, sel: %d!!!!!!\n",
 588                             vcpu->arch.pc, rt, rd, sel);
 589                        er = EMULATE_FAIL;
 590                        break;
 591
 592                case mfmcz_op:
 593#ifdef KVM_MIPS_DEBUG_COP0_COUNTERS
 594                        cop0->stat[MIPS_CP0_STATUS][0]++;
 595#endif
 596                        if (rt != 0) {
 597                                vcpu->arch.gprs[rt] =
 598                                    kvm_read_c0_guest_status(cop0);
 599                        }
 600                        /* EI */
 601                        if (inst & 0x20) {
 602                                kvm_debug("[%#lx] mfmcz_op: EI\n",
 603                                          vcpu->arch.pc);
 604                                kvm_set_c0_guest_status(cop0, ST0_IE);
 605                        } else {
 606                                kvm_debug("[%#lx] mfmcz_op: DI\n",
 607                                          vcpu->arch.pc);
 608                                kvm_clear_c0_guest_status(cop0, ST0_IE);
 609                        }
 610
 611                        break;
 612
 613                case wrpgpr_op:
 614                        {
 615                                uint32_t css =
 616                                    cop0->reg[MIPS_CP0_STATUS][2] & 0xf;
 617                                uint32_t pss =
 618                                    (cop0->reg[MIPS_CP0_STATUS][2] >> 6) & 0xf;
 619                                /* We don't support any shadow register sets, so SRSCtl[PSS] == SRSCtl[CSS] = 0 */
 620                                if (css || pss) {
 621                                        er = EMULATE_FAIL;
 622                                        break;
 623                                }
 624                                kvm_debug("WRPGPR[%d][%d] = %#lx\n", pss, rd,
 625                                          vcpu->arch.gprs[rt]);
 626                                vcpu->arch.gprs[rd] = vcpu->arch.gprs[rt];
 627                        }
 628                        break;
 629                default:
 630                        printk
 631                            ("[%#lx]MachEmulateCP0: unsupported COP0, copz: 0x%x\n",
 632                             vcpu->arch.pc, copz);
 633                        er = EMULATE_FAIL;
 634                        break;
 635                }
 636        }
 637
 638done:
 639        /*
 640         * Rollback PC only if emulation was unsuccessful
 641         */
 642        if (er == EMULATE_FAIL) {
 643                vcpu->arch.pc = curr_pc;
 644        }
 645
 646dont_update_pc:
 647        /*
 648         * This is for special instructions whose emulation
 649         * updates the PC, so do not overwrite the PC under
 650         * any circumstances
 651         */
 652
 653        return er;
 654}
 655
 656enum emulation_result
 657kvm_mips_emulate_store(uint32_t inst, uint32_t cause,
 658                       struct kvm_run *run, struct kvm_vcpu *vcpu)
 659{
 660        enum emulation_result er = EMULATE_DO_MMIO;
 661        int32_t op, base, rt, offset;
 662        uint32_t bytes;
 663        void *data = run->mmio.data;
 664        unsigned long curr_pc;
 665
 666        /*
 667         * Update PC and hold onto current PC in case there is
 668         * an error and we want to rollback the PC
 669         */
 670        curr_pc = vcpu->arch.pc;
 671        er = update_pc(vcpu, cause);
 672        if (er == EMULATE_FAIL)
 673                return er;
 674
 675        rt = (inst >> 16) & 0x1f;
 676        base = (inst >> 21) & 0x1f;
 677        offset = inst & 0xffff;
 678        op = (inst >> 26) & 0x3f;
 679
 680        switch (op) {
 681        case sb_op:
 682                bytes = 1;
 683                if (bytes > sizeof(run->mmio.data)) {
 684                        kvm_err("%s: bad MMIO length: %d\n", __func__,
 685                               run->mmio.len);
 686                }
 687                run->mmio.phys_addr =
 688                    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
 689                                                   host_cp0_badvaddr);
 690                if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
 691                        er = EMULATE_FAIL;
 692                        break;
 693                }
 694                run->mmio.len = bytes;
 695                run->mmio.is_write = 1;
 696                vcpu->mmio_needed = 1;
 697                vcpu->mmio_is_write = 1;
 698                *(u8 *) data = vcpu->arch.gprs[rt];
 699                kvm_debug("OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",
 700                          vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt],
 701                          *(uint8_t *) data);
 702
 703                break;
 704
 705        case sw_op:
 706                bytes = 4;
 707                if (bytes > sizeof(run->mmio.data)) {
 708                        kvm_err("%s: bad MMIO length: %d\n", __func__,
 709                               run->mmio.len);
 710                }
 711                run->mmio.phys_addr =
 712                    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
 713                                                   host_cp0_badvaddr);
 714                if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
 715                        er = EMULATE_FAIL;
 716                        break;
 717                }
 718
 719                run->mmio.len = bytes;
 720                run->mmio.is_write = 1;
 721                vcpu->mmio_needed = 1;
 722                vcpu->mmio_is_write = 1;
 723                *(uint32_t *) data = vcpu->arch.gprs[rt];
 724
 725                kvm_debug("[%#lx] OP_SW: eaddr: %#lx, gpr: %#lx, data: %#x\n",
 726                          vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
 727                          vcpu->arch.gprs[rt], *(uint32_t *) data);
 728                break;
 729
 730        case sh_op:
 731                bytes = 2;
 732                if (bytes > sizeof(run->mmio.data)) {
 733                        kvm_err("%s: bad MMIO length: %d\n", __func__,
 734                               run->mmio.len);
 735                }
 736                run->mmio.phys_addr =
 737                    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
 738                                                   host_cp0_badvaddr);
 739                if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
 740                        er = EMULATE_FAIL;
 741                        break;
 742                }
 743
 744                run->mmio.len = bytes;
 745                run->mmio.is_write = 1;
 746                vcpu->mmio_needed = 1;
 747                vcpu->mmio_is_write = 1;
 748                *(uint16_t *) data = vcpu->arch.gprs[rt];
 749
 750                kvm_debug("[%#lx] OP_SH: eaddr: %#lx, gpr: %#lx, data: %#x\n",
 751                          vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,
 752                          vcpu->arch.gprs[rt], *(uint32_t *) data);
 753                break;
 754
 755        default:
 756                printk("Store not yet supported");
 757                er = EMULATE_FAIL;
 758                break;
 759        }
 760
 761        /*
 762         * Rollback PC if emulation was unsuccessful
 763         */
 764        if (er == EMULATE_FAIL) {
 765                vcpu->arch.pc = curr_pc;
 766        }
 767
 768        return er;
 769}
 770
 771enum emulation_result
 772kvm_mips_emulate_load(uint32_t inst, uint32_t cause,
 773                      struct kvm_run *run, struct kvm_vcpu *vcpu)
 774{
 775        enum emulation_result er = EMULATE_DO_MMIO;
 776        int32_t op, base, rt, offset;
 777        uint32_t bytes;
 778
 779        rt = (inst >> 16) & 0x1f;
 780        base = (inst >> 21) & 0x1f;
 781        offset = inst & 0xffff;
 782        op = (inst >> 26) & 0x3f;
 783
 784        vcpu->arch.pending_load_cause = cause;
 785        vcpu->arch.io_gpr = rt;
 786
 787        switch (op) {
 788        case lw_op:
 789                bytes = 4;
 790                if (bytes > sizeof(run->mmio.data)) {
 791                        kvm_err("%s: bad MMIO length: %d\n", __func__,
 792                               run->mmio.len);
 793                        er = EMULATE_FAIL;
 794                        break;
 795                }
 796                run->mmio.phys_addr =
 797                    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
 798                                                   host_cp0_badvaddr);
 799                if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
 800                        er = EMULATE_FAIL;
 801                        break;
 802                }
 803
 804                run->mmio.len = bytes;
 805                run->mmio.is_write = 0;
 806                vcpu->mmio_needed = 1;
 807                vcpu->mmio_is_write = 0;
 808                break;
 809
 810        case lh_op:
 811        case lhu_op:
 812                bytes = 2;
 813                if (bytes > sizeof(run->mmio.data)) {
 814                        kvm_err("%s: bad MMIO length: %d\n", __func__,
 815                               run->mmio.len);
 816                        er = EMULATE_FAIL;
 817                        break;
 818                }
 819                run->mmio.phys_addr =
 820                    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
 821                                                   host_cp0_badvaddr);
 822                if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
 823                        er = EMULATE_FAIL;
 824                        break;
 825                }
 826
 827                run->mmio.len = bytes;
 828                run->mmio.is_write = 0;
 829                vcpu->mmio_needed = 1;
 830                vcpu->mmio_is_write = 0;
 831
 832                if (op == lh_op)
 833                        vcpu->mmio_needed = 2;
 834                else
 835                        vcpu->mmio_needed = 1;
 836
 837                break;
 838
 839        case lbu_op:
 840        case lb_op:
 841                bytes = 1;
 842                if (bytes > sizeof(run->mmio.data)) {
 843                        kvm_err("%s: bad MMIO length: %d\n", __func__,
 844                               run->mmio.len);
 845                        er = EMULATE_FAIL;
 846                        break;
 847                }
 848                run->mmio.phys_addr =
 849                    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.
 850                                                   host_cp0_badvaddr);
 851                if (run->mmio.phys_addr == KVM_INVALID_ADDR) {
 852                        er = EMULATE_FAIL;
 853                        break;
 854                }
 855
 856                run->mmio.len = bytes;
 857                run->mmio.is_write = 0;
 858                vcpu->mmio_is_write = 0;
 859
 860                if (op == lb_op)
 861                        vcpu->mmio_needed = 2;
 862                else
 863                        vcpu->mmio_needed = 1;
 864
 865                break;
 866
 867        default:
 868                printk("Load not yet supported");
 869                er = EMULATE_FAIL;
 870                break;
 871        }
 872
 873        return er;
 874}
 875
 876int kvm_mips_sync_icache(unsigned long va, struct kvm_vcpu *vcpu)
 877{
 878        unsigned long offset = (va & ~PAGE_MASK);
 879        struct kvm *kvm = vcpu->kvm;
 880        unsigned long pa;
 881        gfn_t gfn;
 882        pfn_t pfn;
 883
 884        gfn = va >> PAGE_SHIFT;
 885
 886        if (gfn >= kvm->arch.guest_pmap_npages) {
 887                printk("%s: Invalid gfn: %#llx\n", __func__, gfn);
 888                kvm_mips_dump_host_tlbs();
 889                kvm_arch_vcpu_dump_regs(vcpu);
 890                return -1;
 891        }
 892        pfn = kvm->arch.guest_pmap[gfn];
 893        pa = (pfn << PAGE_SHIFT) | offset;
 894
 895        printk("%s: va: %#lx, unmapped: %#x\n", __func__, va, CKSEG0ADDR(pa));
 896
 897        mips32_SyncICache(CKSEG0ADDR(pa), 32);
 898        return 0;
 899}
 900
 901#define MIPS_CACHE_OP_INDEX_INV         0x0
 902#define MIPS_CACHE_OP_INDEX_LD_TAG      0x1
 903#define MIPS_CACHE_OP_INDEX_ST_TAG      0x2
 904#define MIPS_CACHE_OP_IMP               0x3
 905#define MIPS_CACHE_OP_HIT_INV           0x4
 906#define MIPS_CACHE_OP_FILL_WB_INV       0x5
 907#define MIPS_CACHE_OP_HIT_HB            0x6
 908#define MIPS_CACHE_OP_FETCH_LOCK        0x7
 909
 910#define MIPS_CACHE_ICACHE               0x0
 911#define MIPS_CACHE_DCACHE               0x1
 912#define MIPS_CACHE_SEC                  0x3
 913
 914enum emulation_result
 915kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc, uint32_t cause,
 916                       struct kvm_run *run, struct kvm_vcpu *vcpu)
 917{
 918        struct mips_coproc *cop0 = vcpu->arch.cop0;
 919        extern void (*r4k_blast_dcache) (void);
 920        extern void (*r4k_blast_icache) (void);
 921        enum emulation_result er = EMULATE_DONE;
 922        int32_t offset, cache, op_inst, op, base;
 923        struct kvm_vcpu_arch *arch = &vcpu->arch;
 924        unsigned long va;
 925        unsigned long curr_pc;
 926
 927        /*
 928         * Update PC and hold onto current PC in case there is
 929         * an error and we want to rollback the PC
 930         */
 931        curr_pc = vcpu->arch.pc;
 932        er = update_pc(vcpu, cause);
 933        if (er == EMULATE_FAIL)
 934                return er;
 935
 936        base = (inst >> 21) & 0x1f;
 937        op_inst = (inst >> 16) & 0x1f;
 938        offset = inst & 0xffff;
 939        cache = (inst >> 16) & 0x3;
 940        op = (inst >> 18) & 0x7;
 941
 942        va = arch->gprs[base] + offset;
 943
 944        kvm_debug("CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
 945                  cache, op, base, arch->gprs[base], offset);
 946
 947        /* Treat INDEX_INV as a nop, basically issued by Linux on startup to invalidate
 948         * the caches entirely by stepping through all the ways/indexes
 949         */
 950        if (op == MIPS_CACHE_OP_INDEX_INV) {
 951                kvm_debug
 952                    ("@ %#lx/%#lx CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
 953                     vcpu->arch.pc, vcpu->arch.gprs[31], cache, op, base,
 954                     arch->gprs[base], offset);
 955
 956                if (cache == MIPS_CACHE_DCACHE)
 957                        r4k_blast_dcache();
 958                else if (cache == MIPS_CACHE_ICACHE)
 959                        r4k_blast_icache();
 960                else {
 961                        printk("%s: unsupported CACHE INDEX operation\n",
 962                               __func__);
 963                        return EMULATE_FAIL;
 964                }
 965
 966#ifdef CONFIG_KVM_MIPS_DYN_TRANS
 967                kvm_mips_trans_cache_index(inst, opc, vcpu);
 968#endif
 969                goto done;
 970        }
 971
 972        preempt_disable();
 973        if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
 974
 975                if (kvm_mips_host_tlb_lookup(vcpu, va) < 0) {
 976                        kvm_mips_handle_kseg0_tlb_fault(va, vcpu);
 977                }
 978        } else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) ||
 979                   KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
 980                int index;
 981
 982                /* If an entry already exists then skip */
 983                if (kvm_mips_host_tlb_lookup(vcpu, va) >= 0) {
 984                        goto skip_fault;
 985                }
 986
 987                /* If address not in the guest TLB, then give the guest a fault, the
 988                 * resulting handler will do the right thing
 989                 */
 990                index = kvm_mips_guest_tlb_lookup(vcpu, (va & VPN2_MASK) |
 991                                                  (kvm_read_c0_guest_entryhi
 992                                                   (cop0) & ASID_MASK));
 993
 994                if (index < 0) {
 995                        vcpu->arch.host_cp0_entryhi = (va & VPN2_MASK);
 996                        vcpu->arch.host_cp0_badvaddr = va;
 997                        er = kvm_mips_emulate_tlbmiss_ld(cause, NULL, run,
 998                                                         vcpu);
 999                        preempt_enable();
1000                        goto dont_update_pc;
1001                } else {
1002                        struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
1003                        /* Check if the entry is valid, if not then setup a TLB invalid exception to the guest */
1004                        if (!TLB_IS_VALID(*tlb, va)) {
1005                                er = kvm_mips_emulate_tlbinv_ld(cause, NULL,
1006                                                                run, vcpu);
1007                                preempt_enable();
1008                                goto dont_update_pc;
1009                        } else {
1010                                /* We fault an entry from the guest tlb to the shadow host TLB */
1011                                kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
1012                                                                     NULL,
1013                                                                     NULL);
1014                        }
1015                }
1016        } else {
1017                printk
1018                    ("INVALID CACHE INDEX/ADDRESS (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1019                     cache, op, base, arch->gprs[base], offset);
1020                er = EMULATE_FAIL;
1021                preempt_enable();
1022                goto dont_update_pc;
1023
1024        }
1025
1026skip_fault:
1027        /* XXXKYMA: Only a subset of cache ops are supported, used by Linux */
1028        if (cache == MIPS_CACHE_DCACHE
1029            && (op == MIPS_CACHE_OP_FILL_WB_INV
1030                || op == MIPS_CACHE_OP_HIT_INV)) {
1031                flush_dcache_line(va);
1032
1033#ifdef CONFIG_KVM_MIPS_DYN_TRANS
1034                /* Replace the CACHE instruction, with a SYNCI, not the same, but avoids a trap */
1035                kvm_mips_trans_cache_va(inst, opc, vcpu);
1036#endif
1037        } else if (op == MIPS_CACHE_OP_HIT_INV && cache == MIPS_CACHE_ICACHE) {
1038                flush_dcache_line(va);
1039                flush_icache_line(va);
1040
1041#ifdef CONFIG_KVM_MIPS_DYN_TRANS
1042                /* Replace the CACHE instruction, with a SYNCI */
1043                kvm_mips_trans_cache_va(inst, opc, vcpu);
1044#endif
1045        } else {
1046                printk
1047                    ("NO-OP CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
1048                     cache, op, base, arch->gprs[base], offset);
1049                er = EMULATE_FAIL;
1050                preempt_enable();
1051                goto dont_update_pc;
1052        }
1053
1054        preempt_enable();
1055
1056      dont_update_pc:
1057        /*
1058         * Rollback PC
1059         */
1060        vcpu->arch.pc = curr_pc;
1061      done:
1062        return er;
1063}
1064
1065enum emulation_result
1066kvm_mips_emulate_inst(unsigned long cause, uint32_t *opc,
1067                      struct kvm_run *run, struct kvm_vcpu *vcpu)
1068{
1069        enum emulation_result er = EMULATE_DONE;
1070        uint32_t inst;
1071
1072        /*
1073         *  Fetch the instruction.
1074         */
1075        if (cause & CAUSEF_BD) {
1076                opc += 1;
1077        }
1078
1079        inst = kvm_get_inst(opc, vcpu);
1080
1081        switch (((union mips_instruction)inst).r_format.opcode) {
1082        case cop0_op:
1083                er = kvm_mips_emulate_CP0(inst, opc, cause, run, vcpu);
1084                break;
1085        case sb_op:
1086        case sh_op:
1087        case sw_op:
1088                er = kvm_mips_emulate_store(inst, cause, run, vcpu);
1089                break;
1090        case lb_op:
1091        case lbu_op:
1092        case lhu_op:
1093        case lh_op:
1094        case lw_op:
1095                er = kvm_mips_emulate_load(inst, cause, run, vcpu);
1096                break;
1097
1098        case cache_op:
1099                ++vcpu->stat.cache_exits;
1100                trace_kvm_exit(vcpu, CACHE_EXITS);
1101                er = kvm_mips_emulate_cache(inst, opc, cause, run, vcpu);
1102                break;
1103
1104        default:
1105                printk("Instruction emulation not supported (%p/%#x)\n", opc,
1106                       inst);
1107                kvm_arch_vcpu_dump_regs(vcpu);
1108                er = EMULATE_FAIL;
1109                break;
1110        }
1111
1112        return er;
1113}
1114
1115enum emulation_result
1116kvm_mips_emulate_syscall(unsigned long cause, uint32_t *opc,
1117                         struct kvm_run *run, struct kvm_vcpu *vcpu)
1118{
1119        struct mips_coproc *cop0 = vcpu->arch.cop0;
1120        struct kvm_vcpu_arch *arch = &vcpu->arch;
1121        enum emulation_result er = EMULATE_DONE;
1122
1123        if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1124                /* save old pc */
1125                kvm_write_c0_guest_epc(cop0, arch->pc);
1126                kvm_set_c0_guest_status(cop0, ST0_EXL);
1127
1128                if (cause & CAUSEF_BD)
1129                        kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1130                else
1131                        kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1132
1133                kvm_debug("Delivering SYSCALL @ pc %#lx\n", arch->pc);
1134
1135                kvm_change_c0_guest_cause(cop0, (0xff),
1136                                          (T_SYSCALL << CAUSEB_EXCCODE));
1137
1138                /* Set PC to the exception entry point */
1139                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1140
1141        } else {
1142                printk("Trying to deliver SYSCALL when EXL is already set\n");
1143                er = EMULATE_FAIL;
1144        }
1145
1146        return er;
1147}
1148
1149enum emulation_result
1150kvm_mips_emulate_tlbmiss_ld(unsigned long cause, uint32_t *opc,
1151                            struct kvm_run *run, struct kvm_vcpu *vcpu)
1152{
1153        struct mips_coproc *cop0 = vcpu->arch.cop0;
1154        struct kvm_vcpu_arch *arch = &vcpu->arch;
1155        enum emulation_result er = EMULATE_DONE;
1156        unsigned long entryhi = (vcpu->arch.  host_cp0_badvaddr & VPN2_MASK) |
1157                                (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1158
1159        if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1160                /* save old pc */
1161                kvm_write_c0_guest_epc(cop0, arch->pc);
1162                kvm_set_c0_guest_status(cop0, ST0_EXL);
1163
1164                if (cause & CAUSEF_BD)
1165                        kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1166                else
1167                        kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1168
1169                kvm_debug("[EXL == 0] delivering TLB MISS @ pc %#lx\n",
1170                          arch->pc);
1171
1172                /* set pc to the exception entry point */
1173                arch->pc = KVM_GUEST_KSEG0 + 0x0;
1174
1175        } else {
1176                kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1177                          arch->pc);
1178
1179                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1180        }
1181
1182        kvm_change_c0_guest_cause(cop0, (0xff),
1183                                  (T_TLB_LD_MISS << CAUSEB_EXCCODE));
1184
1185        /* setup badvaddr, context and entryhi registers for the guest */
1186        kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1187        /* XXXKYMA: is the context register used by linux??? */
1188        kvm_write_c0_guest_entryhi(cop0, entryhi);
1189        /* Blow away the shadow host TLBs */
1190        kvm_mips_flush_host_tlb(1);
1191
1192        return er;
1193}
1194
1195enum emulation_result
1196kvm_mips_emulate_tlbinv_ld(unsigned long cause, uint32_t *opc,
1197                           struct kvm_run *run, struct kvm_vcpu *vcpu)
1198{
1199        struct mips_coproc *cop0 = vcpu->arch.cop0;
1200        struct kvm_vcpu_arch *arch = &vcpu->arch;
1201        enum emulation_result er = EMULATE_DONE;
1202        unsigned long entryhi =
1203                (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1204                (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1205
1206        if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1207                /* save old pc */
1208                kvm_write_c0_guest_epc(cop0, arch->pc);
1209                kvm_set_c0_guest_status(cop0, ST0_EXL);
1210
1211                if (cause & CAUSEF_BD)
1212                        kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1213                else
1214                        kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1215
1216                kvm_debug("[EXL == 0] delivering TLB INV @ pc %#lx\n",
1217                          arch->pc);
1218
1219                /* set pc to the exception entry point */
1220                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1221
1222        } else {
1223                kvm_debug("[EXL == 1] delivering TLB MISS @ pc %#lx\n",
1224                          arch->pc);
1225                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1226        }
1227
1228        kvm_change_c0_guest_cause(cop0, (0xff),
1229                                  (T_TLB_LD_MISS << CAUSEB_EXCCODE));
1230
1231        /* setup badvaddr, context and entryhi registers for the guest */
1232        kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1233        /* XXXKYMA: is the context register used by linux??? */
1234        kvm_write_c0_guest_entryhi(cop0, entryhi);
1235        /* Blow away the shadow host TLBs */
1236        kvm_mips_flush_host_tlb(1);
1237
1238        return er;
1239}
1240
1241enum emulation_result
1242kvm_mips_emulate_tlbmiss_st(unsigned long cause, uint32_t *opc,
1243                            struct kvm_run *run, struct kvm_vcpu *vcpu)
1244{
1245        struct mips_coproc *cop0 = vcpu->arch.cop0;
1246        struct kvm_vcpu_arch *arch = &vcpu->arch;
1247        enum emulation_result er = EMULATE_DONE;
1248        unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1249                                (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1250
1251        if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1252                /* save old pc */
1253                kvm_write_c0_guest_epc(cop0, arch->pc);
1254                kvm_set_c0_guest_status(cop0, ST0_EXL);
1255
1256                if (cause & CAUSEF_BD)
1257                        kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1258                else
1259                        kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1260
1261                kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
1262                          arch->pc);
1263
1264                /* Set PC to the exception entry point */
1265                arch->pc = KVM_GUEST_KSEG0 + 0x0;
1266        } else {
1267                kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
1268                          arch->pc);
1269                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1270        }
1271
1272        kvm_change_c0_guest_cause(cop0, (0xff),
1273                                  (T_TLB_ST_MISS << CAUSEB_EXCCODE));
1274
1275        /* setup badvaddr, context and entryhi registers for the guest */
1276        kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1277        /* XXXKYMA: is the context register used by linux??? */
1278        kvm_write_c0_guest_entryhi(cop0, entryhi);
1279        /* Blow away the shadow host TLBs */
1280        kvm_mips_flush_host_tlb(1);
1281
1282        return er;
1283}
1284
1285enum emulation_result
1286kvm_mips_emulate_tlbinv_st(unsigned long cause, uint32_t *opc,
1287                           struct kvm_run *run, struct kvm_vcpu *vcpu)
1288{
1289        struct mips_coproc *cop0 = vcpu->arch.cop0;
1290        struct kvm_vcpu_arch *arch = &vcpu->arch;
1291        enum emulation_result er = EMULATE_DONE;
1292        unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1293                (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1294
1295        if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1296                /* save old pc */
1297                kvm_write_c0_guest_epc(cop0, arch->pc);
1298                kvm_set_c0_guest_status(cop0, ST0_EXL);
1299
1300                if (cause & CAUSEF_BD)
1301                        kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1302                else
1303                        kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1304
1305                kvm_debug("[EXL == 0] Delivering TLB MISS @ pc %#lx\n",
1306                          arch->pc);
1307
1308                /* Set PC to the exception entry point */
1309                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1310        } else {
1311                kvm_debug("[EXL == 1] Delivering TLB MISS @ pc %#lx\n",
1312                          arch->pc);
1313                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1314        }
1315
1316        kvm_change_c0_guest_cause(cop0, (0xff),
1317                                  (T_TLB_ST_MISS << CAUSEB_EXCCODE));
1318
1319        /* setup badvaddr, context and entryhi registers for the guest */
1320        kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1321        /* XXXKYMA: is the context register used by linux??? */
1322        kvm_write_c0_guest_entryhi(cop0, entryhi);
1323        /* Blow away the shadow host TLBs */
1324        kvm_mips_flush_host_tlb(1);
1325
1326        return er;
1327}
1328
1329/* TLBMOD: store into address matching TLB with Dirty bit off */
1330enum emulation_result
1331kvm_mips_handle_tlbmod(unsigned long cause, uint32_t *opc,
1332                       struct kvm_run *run, struct kvm_vcpu *vcpu)
1333{
1334        enum emulation_result er = EMULATE_DONE;
1335
1336#ifdef DEBUG
1337        /*
1338         * If address not in the guest TLB, then we are in trouble
1339         */
1340        index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
1341        if (index < 0) {
1342                /* XXXKYMA Invalidate and retry */
1343                kvm_mips_host_tlb_inv(vcpu, vcpu->arch.host_cp0_badvaddr);
1344                kvm_err("%s: host got TLBMOD for %#lx but entry not present in Guest TLB\n",
1345                     __func__, entryhi);
1346                kvm_mips_dump_guest_tlbs(vcpu);
1347                kvm_mips_dump_host_tlbs();
1348                return EMULATE_FAIL;
1349        }
1350#endif
1351
1352        er = kvm_mips_emulate_tlbmod(cause, opc, run, vcpu);
1353        return er;
1354}
1355
1356enum emulation_result
1357kvm_mips_emulate_tlbmod(unsigned long cause, uint32_t *opc,
1358                        struct kvm_run *run, struct kvm_vcpu *vcpu)
1359{
1360        struct mips_coproc *cop0 = vcpu->arch.cop0;
1361        unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
1362                                (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
1363        struct kvm_vcpu_arch *arch = &vcpu->arch;
1364        enum emulation_result er = EMULATE_DONE;
1365
1366        if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1367                /* save old pc */
1368                kvm_write_c0_guest_epc(cop0, arch->pc);
1369                kvm_set_c0_guest_status(cop0, ST0_EXL);
1370
1371                if (cause & CAUSEF_BD)
1372                        kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1373                else
1374                        kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1375
1376                kvm_debug("[EXL == 0] Delivering TLB MOD @ pc %#lx\n",
1377                          arch->pc);
1378
1379                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1380        } else {
1381                kvm_debug("[EXL == 1] Delivering TLB MOD @ pc %#lx\n",
1382                          arch->pc);
1383                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1384        }
1385
1386        kvm_change_c0_guest_cause(cop0, (0xff), (T_TLB_MOD << CAUSEB_EXCCODE));
1387
1388        /* setup badvaddr, context and entryhi registers for the guest */
1389        kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1390        /* XXXKYMA: is the context register used by linux??? */
1391        kvm_write_c0_guest_entryhi(cop0, entryhi);
1392        /* Blow away the shadow host TLBs */
1393        kvm_mips_flush_host_tlb(1);
1394
1395        return er;
1396}
1397
1398enum emulation_result
1399kvm_mips_emulate_fpu_exc(unsigned long cause, uint32_t *opc,
1400                         struct kvm_run *run, struct kvm_vcpu *vcpu)
1401{
1402        struct mips_coproc *cop0 = vcpu->arch.cop0;
1403        struct kvm_vcpu_arch *arch = &vcpu->arch;
1404        enum emulation_result er = EMULATE_DONE;
1405
1406        if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1407                /* save old pc */
1408                kvm_write_c0_guest_epc(cop0, arch->pc);
1409                kvm_set_c0_guest_status(cop0, ST0_EXL);
1410
1411                if (cause & CAUSEF_BD)
1412                        kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1413                else
1414                        kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1415
1416        }
1417
1418        arch->pc = KVM_GUEST_KSEG0 + 0x180;
1419
1420        kvm_change_c0_guest_cause(cop0, (0xff),
1421                                  (T_COP_UNUSABLE << CAUSEB_EXCCODE));
1422        kvm_change_c0_guest_cause(cop0, (CAUSEF_CE), (0x1 << CAUSEB_CE));
1423
1424        return er;
1425}
1426
1427enum emulation_result
1428kvm_mips_emulate_ri_exc(unsigned long cause, uint32_t *opc,
1429                        struct kvm_run *run, struct kvm_vcpu *vcpu)
1430{
1431        struct mips_coproc *cop0 = vcpu->arch.cop0;
1432        struct kvm_vcpu_arch *arch = &vcpu->arch;
1433        enum emulation_result er = EMULATE_DONE;
1434
1435        if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1436                /* save old pc */
1437                kvm_write_c0_guest_epc(cop0, arch->pc);
1438                kvm_set_c0_guest_status(cop0, ST0_EXL);
1439
1440                if (cause & CAUSEF_BD)
1441                        kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1442                else
1443                        kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1444
1445                kvm_debug("Delivering RI @ pc %#lx\n", arch->pc);
1446
1447                kvm_change_c0_guest_cause(cop0, (0xff),
1448                                          (T_RES_INST << CAUSEB_EXCCODE));
1449
1450                /* Set PC to the exception entry point */
1451                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1452
1453        } else {
1454                kvm_err("Trying to deliver RI when EXL is already set\n");
1455                er = EMULATE_FAIL;
1456        }
1457
1458        return er;
1459}
1460
1461enum emulation_result
1462kvm_mips_emulate_bp_exc(unsigned long cause, uint32_t *opc,
1463                        struct kvm_run *run, struct kvm_vcpu *vcpu)
1464{
1465        struct mips_coproc *cop0 = vcpu->arch.cop0;
1466        struct kvm_vcpu_arch *arch = &vcpu->arch;
1467        enum emulation_result er = EMULATE_DONE;
1468
1469        if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1470                /* save old pc */
1471                kvm_write_c0_guest_epc(cop0, arch->pc);
1472                kvm_set_c0_guest_status(cop0, ST0_EXL);
1473
1474                if (cause & CAUSEF_BD)
1475                        kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1476                else
1477                        kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1478
1479                kvm_debug("Delivering BP @ pc %#lx\n", arch->pc);
1480
1481                kvm_change_c0_guest_cause(cop0, (0xff),
1482                                          (T_BREAK << CAUSEB_EXCCODE));
1483
1484                /* Set PC to the exception entry point */
1485                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1486
1487        } else {
1488                printk("Trying to deliver BP when EXL is already set\n");
1489                er = EMULATE_FAIL;
1490        }
1491
1492        return er;
1493}
1494
1495/*
1496 * ll/sc, rdhwr, sync emulation
1497 */
1498
1499#define OPCODE 0xfc000000
1500#define BASE   0x03e00000
1501#define RT     0x001f0000
1502#define OFFSET 0x0000ffff
1503#define LL     0xc0000000
1504#define SC     0xe0000000
1505#define SPEC0  0x00000000
1506#define SPEC3  0x7c000000
1507#define RD     0x0000f800
1508#define FUNC   0x0000003f
1509#define SYNC   0x0000000f
1510#define RDHWR  0x0000003b
1511
1512enum emulation_result
1513kvm_mips_handle_ri(unsigned long cause, uint32_t *opc,
1514                   struct kvm_run *run, struct kvm_vcpu *vcpu)
1515{
1516        struct mips_coproc *cop0 = vcpu->arch.cop0;
1517        struct kvm_vcpu_arch *arch = &vcpu->arch;
1518        enum emulation_result er = EMULATE_DONE;
1519        unsigned long curr_pc;
1520        uint32_t inst;
1521
1522        /*
1523         * Update PC and hold onto current PC in case there is
1524         * an error and we want to rollback the PC
1525         */
1526        curr_pc = vcpu->arch.pc;
1527        er = update_pc(vcpu, cause);
1528        if (er == EMULATE_FAIL)
1529                return er;
1530
1531        /*
1532         *  Fetch the instruction.
1533         */
1534        if (cause & CAUSEF_BD)
1535                opc += 1;
1536
1537        inst = kvm_get_inst(opc, vcpu);
1538
1539        if (inst == KVM_INVALID_INST) {
1540                printk("%s: Cannot get inst @ %p\n", __func__, opc);
1541                return EMULATE_FAIL;
1542        }
1543
1544        if ((inst & OPCODE) == SPEC3 && (inst & FUNC) == RDHWR) {
1545                int rd = (inst & RD) >> 11;
1546                int rt = (inst & RT) >> 16;
1547                switch (rd) {
1548                case 0: /* CPU number */
1549                        arch->gprs[rt] = 0;
1550                        break;
1551                case 1: /* SYNCI length */
1552                        arch->gprs[rt] = min(current_cpu_data.dcache.linesz,
1553                                             current_cpu_data.icache.linesz);
1554                        break;
1555                case 2: /* Read count register */
1556                        printk("RDHWR: Cont register\n");
1557                        arch->gprs[rt] = kvm_read_c0_guest_count(cop0);
1558                        break;
1559                case 3: /* Count register resolution */
1560                        switch (current_cpu_data.cputype) {
1561                        case CPU_20KC:
1562                        case CPU_25KF:
1563                                arch->gprs[rt] = 1;
1564                                break;
1565                        default:
1566                                arch->gprs[rt] = 2;
1567                        }
1568                        break;
1569                case 29:
1570#if 1
1571                        arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0);
1572#else
1573                        /* UserLocal not implemented */
1574                        er = kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
1575#endif
1576                        break;
1577
1578                default:
1579                        printk("RDHWR not supported\n");
1580                        er = EMULATE_FAIL;
1581                        break;
1582                }
1583        } else {
1584                printk("Emulate RI not supported @ %p: %#x\n", opc, inst);
1585                er = EMULATE_FAIL;
1586        }
1587
1588        /*
1589         * Rollback PC only if emulation was unsuccessful
1590         */
1591        if (er == EMULATE_FAIL) {
1592                vcpu->arch.pc = curr_pc;
1593        }
1594        return er;
1595}
1596
1597enum emulation_result
1598kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run)
1599{
1600        unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
1601        enum emulation_result er = EMULATE_DONE;
1602        unsigned long curr_pc;
1603
1604        if (run->mmio.len > sizeof(*gpr)) {
1605                printk("Bad MMIO length: %d", run->mmio.len);
1606                er = EMULATE_FAIL;
1607                goto done;
1608        }
1609
1610        /*
1611         * Update PC and hold onto current PC in case there is
1612         * an error and we want to rollback the PC
1613         */
1614        curr_pc = vcpu->arch.pc;
1615        er = update_pc(vcpu, vcpu->arch.pending_load_cause);
1616        if (er == EMULATE_FAIL)
1617                return er;
1618
1619        switch (run->mmio.len) {
1620        case 4:
1621                *gpr = *(int32_t *) run->mmio.data;
1622                break;
1623
1624        case 2:
1625                if (vcpu->mmio_needed == 2)
1626                        *gpr = *(int16_t *) run->mmio.data;
1627                else
1628                        *gpr = *(int16_t *) run->mmio.data;
1629
1630                break;
1631        case 1:
1632                if (vcpu->mmio_needed == 2)
1633                        *gpr = *(int8_t *) run->mmio.data;
1634                else
1635                        *gpr = *(u8 *) run->mmio.data;
1636                break;
1637        }
1638
1639        if (vcpu->arch.pending_load_cause & CAUSEF_BD)
1640                kvm_debug
1641                    ("[%#lx] Completing %d byte BD Load to gpr %d (0x%08lx) type %d\n",
1642                     vcpu->arch.pc, run->mmio.len, vcpu->arch.io_gpr, *gpr,
1643                     vcpu->mmio_needed);
1644
1645done:
1646        return er;
1647}
1648
1649static enum emulation_result
1650kvm_mips_emulate_exc(unsigned long cause, uint32_t *opc,
1651                     struct kvm_run *run, struct kvm_vcpu *vcpu)
1652{
1653        uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
1654        struct mips_coproc *cop0 = vcpu->arch.cop0;
1655        struct kvm_vcpu_arch *arch = &vcpu->arch;
1656        enum emulation_result er = EMULATE_DONE;
1657
1658        if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
1659                /* save old pc */
1660                kvm_write_c0_guest_epc(cop0, arch->pc);
1661                kvm_set_c0_guest_status(cop0, ST0_EXL);
1662
1663                if (cause & CAUSEF_BD)
1664                        kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
1665                else
1666                        kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
1667
1668                kvm_change_c0_guest_cause(cop0, (0xff),
1669                                          (exccode << CAUSEB_EXCCODE));
1670
1671                /* Set PC to the exception entry point */
1672                arch->pc = KVM_GUEST_KSEG0 + 0x180;
1673                kvm_write_c0_guest_badvaddr(cop0, vcpu->arch.host_cp0_badvaddr);
1674
1675                kvm_debug("Delivering EXC %d @ pc %#lx, badVaddr: %#lx\n",
1676                          exccode, kvm_read_c0_guest_epc(cop0),
1677                          kvm_read_c0_guest_badvaddr(cop0));
1678        } else {
1679                printk("Trying to deliver EXC when EXL is already set\n");
1680                er = EMULATE_FAIL;
1681        }
1682
1683        return er;
1684}
1685
1686enum emulation_result
1687kvm_mips_check_privilege(unsigned long cause, uint32_t *opc,
1688                         struct kvm_run *run, struct kvm_vcpu *vcpu)
1689{
1690        enum emulation_result er = EMULATE_DONE;
1691        uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
1692        unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
1693
1694        int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
1695
1696        if (usermode) {
1697                switch (exccode) {
1698                case T_INT:
1699                case T_SYSCALL:
1700                case T_BREAK:
1701                case T_RES_INST:
1702                        break;
1703
1704                case T_COP_UNUSABLE:
1705                        if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 0)
1706                                er = EMULATE_PRIV_FAIL;
1707                        break;
1708
1709                case T_TLB_MOD:
1710                        break;
1711
1712                case T_TLB_LD_MISS:
1713                        /* We we are accessing Guest kernel space, then send an address error exception to the guest */
1714                        if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
1715                                printk("%s: LD MISS @ %#lx\n", __func__,
1716                                       badvaddr);
1717                                cause &= ~0xff;
1718                                cause |= (T_ADDR_ERR_LD << CAUSEB_EXCCODE);
1719                                er = EMULATE_PRIV_FAIL;
1720                        }
1721                        break;
1722
1723                case T_TLB_ST_MISS:
1724                        /* We we are accessing Guest kernel space, then send an address error exception to the guest */
1725                        if (badvaddr >= (unsigned long) KVM_GUEST_KSEG0) {
1726                                printk("%s: ST MISS @ %#lx\n", __func__,
1727                                       badvaddr);
1728                                cause &= ~0xff;
1729                                cause |= (T_ADDR_ERR_ST << CAUSEB_EXCCODE);
1730                                er = EMULATE_PRIV_FAIL;
1731                        }
1732                        break;
1733
1734                case T_ADDR_ERR_ST:
1735                        printk("%s: address error ST @ %#lx\n", __func__,
1736                               badvaddr);
1737                        if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
1738                                cause &= ~0xff;
1739                                cause |= (T_TLB_ST_MISS << CAUSEB_EXCCODE);
1740                        }
1741                        er = EMULATE_PRIV_FAIL;
1742                        break;
1743                case T_ADDR_ERR_LD:
1744                        printk("%s: address error LD @ %#lx\n", __func__,
1745                               badvaddr);
1746                        if ((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR) {
1747                                cause &= ~0xff;
1748                                cause |= (T_TLB_LD_MISS << CAUSEB_EXCCODE);
1749                        }
1750                        er = EMULATE_PRIV_FAIL;
1751                        break;
1752                default:
1753                        er = EMULATE_PRIV_FAIL;
1754                        break;
1755                }
1756        }
1757
1758        if (er == EMULATE_PRIV_FAIL) {
1759                kvm_mips_emulate_exc(cause, opc, run, vcpu);
1760        }
1761        return er;
1762}
1763
1764/* User Address (UA) fault, this could happen if
1765 * (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this
1766 *     case we pass on the fault to the guest kernel and let it handle it.
1767 * (2) TLB entry is present in the Guest TLB but not in the shadow, in this
1768 *     case we inject the TLB from the Guest TLB into the shadow host TLB
1769 */
1770enum emulation_result
1771kvm_mips_handle_tlbmiss(unsigned long cause, uint32_t *opc,
1772                        struct kvm_run *run, struct kvm_vcpu *vcpu)
1773{
1774        enum emulation_result er = EMULATE_DONE;
1775        uint32_t exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
1776        unsigned long va = vcpu->arch.host_cp0_badvaddr;
1777        int index;
1778
1779        kvm_debug("kvm_mips_handle_tlbmiss: badvaddr: %#lx, entryhi: %#lx\n",
1780                  vcpu->arch.host_cp0_badvaddr, vcpu->arch.host_cp0_entryhi);
1781
1782        /* KVM would not have got the exception if this entry was valid in the shadow host TLB
1783         * Check the Guest TLB, if the entry is not there then send the guest an
1784         * exception. The guest exc handler should then inject an entry into the
1785         * guest TLB
1786         */
1787        index = kvm_mips_guest_tlb_lookup(vcpu,
1788                                          (va & VPN2_MASK) |
1789                                          (kvm_read_c0_guest_entryhi
1790                                           (vcpu->arch.cop0) & ASID_MASK));
1791        if (index < 0) {
1792                if (exccode == T_TLB_LD_MISS) {
1793                        er = kvm_mips_emulate_tlbmiss_ld(cause, opc, run, vcpu);
1794                } else if (exccode == T_TLB_ST_MISS) {
1795                        er = kvm_mips_emulate_tlbmiss_st(cause, opc, run, vcpu);
1796                } else {
1797                        printk("%s: invalid exc code: %d\n", __func__, exccode);
1798                        er = EMULATE_FAIL;
1799                }
1800        } else {
1801                struct kvm_mips_tlb *tlb = &vcpu->arch.guest_tlb[index];
1802
1803                /* Check if the entry is valid, if not then setup a TLB invalid exception to the guest */
1804                if (!TLB_IS_VALID(*tlb, va)) {
1805                        if (exccode == T_TLB_LD_MISS) {
1806                                er = kvm_mips_emulate_tlbinv_ld(cause, opc, run,
1807                                                                vcpu);
1808                        } else if (exccode == T_TLB_ST_MISS) {
1809                                er = kvm_mips_emulate_tlbinv_st(cause, opc, run,
1810                                                                vcpu);
1811                        } else {
1812                                printk("%s: invalid exc code: %d\n", __func__,
1813                                       exccode);
1814                                er = EMULATE_FAIL;
1815                        }
1816                } else {
1817#ifdef DEBUG
1818                        kvm_debug
1819                            ("Injecting hi: %#lx, lo0: %#lx, lo1: %#lx into shadow host TLB\n",
1820                             tlb->tlb_hi, tlb->tlb_lo0, tlb->tlb_lo1);
1821#endif
1822                        /* OK we have a Guest TLB entry, now inject it into the shadow host TLB */
1823                        kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, NULL,
1824                                                             NULL);
1825                }
1826        }
1827
1828        return er;
1829}
1830