arch/powerpc/kvm/emulate.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License, version 2, as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program; if not, write to the Free Software
  13  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  14  *
  15  * Copyright IBM Corp. 2007
  16  * Copyright 2011 Freescale Semiconductor, Inc.
  17  *
  18  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  19  */
  20
  21 #include <linux/jiffies.h>
  22 #include <linux/hrtimer.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/kvm_host.h>
  26 #include <linux/clockchips.h>
  27
  28 #include <asm/reg.h>
  29 #include <asm/time.h>
  30 #include <asm/byteorder.h>
  31 #include <asm/kvm_ppc.h>
  32 #include <asm/disassemble.h>
  33 #include "timing.h"
  34 #include "trace.h"
  35
  36 #define OP_TRAP 3
  37 #define OP_TRAP_64 2
  38
  39 #define OP_31_XOP_TRAP      4
  40 #define OP_31_XOP_LWZX      23
  41 #define OP_31_XOP_TRAP_64   68
  42 #define OP_31_XOP_LBZX      87
  43 #define OP_31_XOP_STWX      151
  44 #define OP_31_XOP_STBX      215
  45 #define OP_31_XOP_LBZUX     119
  46 #define OP_31_XOP_STBUX     247
  47 #define OP_31_XOP_LHZX      279
  48 #define OP_31_XOP_LHZUX     311
  49 #define OP_31_XOP_MFSPR     339
  50 #define OP_31_XOP_LHAX      343
  51 #define OP_31_XOP_STHX      407
  52 #define OP_31_XOP_STHUX     439
  53 #define OP_31_XOP_MTSPR     467
  54 #define OP_31_XOP_DCBI      470
  55 #define OP_31_XOP_LWBRX     534
  56 #define OP_31_XOP_TLBSYNC   566
  57 #define OP_31_XOP_STWBRX    662
  58 #define OP_31_XOP_LHBRX     790
  59 #define OP_31_XOP_STHBRX    918
  60
  61 #define OP_LWZ  32
  62 #define OP_LWZU 33
  63 #define OP_LBZ  34
  64 #define OP_LBZU 35
  65 #define OP_STW  36
  66 #define OP_STWU 37
  67 #define OP_STB  38
  68 #define OP_STBU 39
  69 #define OP_LHZ  40
  70 #define OP_LHZU 41
  71 #define OP_LHA  42
  72 #define OP_LHAU 43
  73 #define OP_STH  44
  74 #define OP_STHU 45
  75
  76 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  77 {
  78         unsigned long dec_nsec;
  79         unsigned long long dec_time;
  80
  81         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  82         hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  83
  84 #ifdef CONFIG_PPC_BOOK3S
  85         /* mtdec lowers the interrupt line when positive. */
  86         kvmppc_core_dequeue_dec(vcpu);
  87
  88         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  89         if (vcpu->arch.dec & 0x80000000) {
  90                 kvmppc_core_queue_dec(vcpu);
  91                 return;
  92         }
  93 #endif
  94
  95 #ifdef CONFIG_BOOKE
  96         /* On BOOKE, DEC = 0 is as good as decrementer not enabled */
  97         if (vcpu->arch.dec == 0)
  98                 return;
  99 #endif
 100
 101         /*
 102          * The decrementer ticks at the same rate as the timebase, so
 103          * that's how we convert the guest DEC value to the number of
 104          * host ticks.
 105          */
 106
 107         dec_time = vcpu->arch.dec;
 108         /*
 109          * Guest timebase ticks at the same frequency as host decrementer.
 110          * So use the host decrementer calculations for decrementer emulation.
 111          */
 112         dec_time = dec_time << decrementer_clockevent.shift;
 113         do_div(dec_time, decrementer_clockevent.mult);
 114         dec_nsec = do_div(dec_time, NSEC_PER_SEC);
 115         hrtimer_start(&vcpu->arch.dec_timer,
 116                 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
 117         vcpu->arch.dec_jiffies = get_tb();
 118 }
 119
 120 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 121 {
 122         u64 jd = tb - vcpu->arch.dec_jiffies;
 123
 124 #ifdef CONFIG_BOOKE
 125         if (vcpu->arch.dec < jd)
 126                 return 0;
 127 #endif
 128
 129         return vcpu->arch.dec - jd;
 130 }
 131
 132 /* XXX to do:
 133  * lhax
 134  * lhaux
 135  * lswx
 136  * lswi
 137  * stswx
 138  * stswi
 139  * lha
 140  * lhau
 141  * lmw
 142  * stmw
 143  *
 144  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 145  */
 146 /* XXX Should probably auto-generate instruction decoding for a particular core
 147  * from opcode tables in the future. */
 148 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 149 {
 150         u32 inst = kvmppc_get_last_inst(vcpu);
 151         int ra;
 152         int rb;
 153         int rs;
 154         int rt;
 155         int sprn;
 156         enum emulation_result emulated = EMULATE_DONE;
 157         int advance = 1;
 158
 159         /* this default type might be overwritten by subcategories */
 160         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 161
 162         pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 163
 164         switch (get_op(inst)) {
 165         case OP_TRAP:
 166 #ifdef CONFIG_PPC_BOOK3S
 167         case OP_TRAP_64:
 168                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 169 #else
 170                 kvmppc_core_queue_program(vcpu,
 171                                           vcpu->arch.shared->esr | ESR_PTR);
 172 #endif
 173                 advance = 0;
 174                 break;
 175
 176         case 31:
 177                 switch (get_xop(inst)) {
 178
 179                 case OP_31_XOP_TRAP:
 180 #ifdef CONFIG_64BIT
 181                 case OP_31_XOP_TRAP_64:
 182 #endif
 183 #ifdef CONFIG_PPC_BOOK3S
 184                         kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 185 #else
 186                         kvmppc_core_queue_program(vcpu,
 187                                         vcpu->arch.shared->esr | ESR_PTR);
 188 #endif
 189                         advance = 0;
 190                         break;
 191                 case OP_31_XOP_LWZX:
 192                         rt = get_rt(inst);
 193                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 194                         break;
 195
 196                 case OP_31_XOP_LBZX:
 197                         rt = get_rt(inst);
 198                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 199                         break;
 200
 201                 case OP_31_XOP_LBZUX:
 202                         rt = get_rt(inst);
 203                         ra = get_ra(inst);
 204                         rb = get_rb(inst);
 205
 206                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 207                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 208                         break;
 209
 210                 case OP_31_XOP_STWX:
 211                         rs = get_rs(inst);
 212                         emulated = kvmppc_handle_store(run, vcpu,
 213                                                        kvmppc_get_gpr(vcpu, rs),
 214                                                        4, 1);
 215                         break;
 216
 217                 case OP_31_XOP_STBX:
 218                         rs = get_rs(inst);
 219                         emulated = kvmppc_handle_store(run, vcpu,
 220                                                        kvmppc_get_gpr(vcpu, rs),
 221                                                        1, 1);
 222                         break;
 223
 224                 case OP_31_XOP_STBUX:
 225                         rs = get_rs(inst);
 226                         ra = get_ra(inst);
 227                         rb = get_rb(inst);
 228
 229                         emulated = kvmppc_handle_store(run, vcpu,
 230                                                        kvmppc_get_gpr(vcpu, rs),
 231                                                        1, 1);
 232                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 233                         break;
 234
 235                 case OP_31_XOP_LHAX:
 236                         rt = get_rt(inst);
 237                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 238                         break;
 239
 240                 case OP_31_XOP_LHZX:
 241                         rt = get_rt(inst);
 242                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 243                         break;
 244
 245                 case OP_31_XOP_LHZUX:
 246                         rt = get_rt(inst);
 247                         ra = get_ra(inst);
 248                         rb = get_rb(inst);
 249
 250                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 251                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 252                         break;
 253
 254                 case OP_31_XOP_MFSPR:
 255                         sprn = get_sprn(inst);
 256                         rt = get_rt(inst);
 257
 258                         switch (sprn) {
 259                         case SPRN_SRR0:
 260                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr0);
 261                                 break;
 262                         case SPRN_SRR1:
 263                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr1);
 264                                 break;
 265                         case SPRN_PVR:
 266                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
 267                         case SPRN_PIR:
 268                                 kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
 269                         case SPRN_MSSSR0:
 270                                 kvmppc_set_gpr(vcpu, rt, 0); break;
 271
 272                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 273                          * the guest can always access the real TB anyways.
 274                          * In fact, we probably will never see these traps. */
 275                         case SPRN_TBWL:
 276                                 kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
 277                         case SPRN_TBWU:
 278                                 kvmppc_set_gpr(vcpu, rt, get_tb()); break;
 279
 280                         case SPRN_SPRG0:
 281                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg0);
 282                                 break;
 283                         case SPRN_SPRG1:
 284                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg1);
 285                                 break;
 286                         case SPRN_SPRG2:
 287                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg2);
 288                                 break;
 289                         case SPRN_SPRG3:
 290                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg3);
 291                                 break;
 292                         /* Note: SPRG4-7 are user-readable, so we don't get
 293                          * a trap. */
 294
 295                         case SPRN_DEC:
 296                         {
 297                                 kvmppc_set_gpr(vcpu, rt,
 298                                                kvmppc_get_dec(vcpu, get_tb()));
 299                                 break;
 300                         }
 301                         default:
 302                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 303                                 if (emulated == EMULATE_FAIL) {
 304                                         printk("mfspr: unknown spr %x\n", sprn);
 305                                         kvmppc_set_gpr(vcpu, rt, 0);
 306                                 }
 307                                 break;
 308                         }
 309                         kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
 310                         break;
 311
 312                 case OP_31_XOP_STHX:
 313                         rs = get_rs(inst);
 314                         ra = get_ra(inst);
 315                         rb = get_rb(inst);
 316
 317                         emulated = kvmppc_handle_store(run, vcpu,
 318                                                        kvmppc_get_gpr(vcpu, rs),
 319                                                        2, 1);
 320                         break;
 321
 322                 case OP_31_XOP_STHUX:
 323                         rs = get_rs(inst);
 324                         ra = get_ra(inst);
 325                         rb = get_rb(inst);
 326
 327                         emulated = kvmppc_handle_store(run, vcpu,
 328                                                        kvmppc_get_gpr(vcpu, rs),
 329                                                        2, 1);
 330                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 331                         break;
 332
 333                 case OP_31_XOP_MTSPR:
 334                         sprn = get_sprn(inst);
 335                         rs = get_rs(inst);
 336                         switch (sprn) {
 337                         case SPRN_SRR0:
 338                                 vcpu->arch.shared->srr0 = kvmppc_get_gpr(vcpu, rs);
 339                                 break;
 340                         case SPRN_SRR1:
 341                                 vcpu->arch.shared->srr1 = kvmppc_get_gpr(vcpu, rs);
 342                                 break;
 343
 344                         /* XXX We need to context-switch the timebase for
 345                          * watchdog and FIT. */
 346                         case SPRN_TBWL: break;
 347                         case SPRN_TBWU: break;
 348
 349                         case SPRN_MSSSR0: break;
 350
 351                         case SPRN_DEC:
 352                                 vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
 353                                 kvmppc_emulate_dec(vcpu);
 354                                 break;
 355
 356                         case SPRN_SPRG0:
 357                                 vcpu->arch.shared->sprg0 = kvmppc_get_gpr(vcpu, rs);
 358                                 break;
 359                         case SPRN_SPRG1:
 360                                 vcpu->arch.shared->sprg1 = kvmppc_get_gpr(vcpu, rs);
 361                                 break;
 362                         case SPRN_SPRG2:
 363                                 vcpu->arch.shared->sprg2 = kvmppc_get_gpr(vcpu, rs);
 364                                 break;
 365                         case SPRN_SPRG3:
 366                                 vcpu->arch.shared->sprg3 = kvmppc_get_gpr(vcpu, rs);
 367                                 break;
 368
 369                         default:
 370                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 371                                 if (emulated == EMULATE_FAIL)
 372                                         printk("mtspr: unknown spr %x\n", sprn);
 373                                 break;
 374                         }
 375                         kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
 376                         break;
 377
 378                 case OP_31_XOP_DCBI:
 379                         /* Do nothing. The guest is performing dcbi because
 380                          * hardware DMA is not snooped by the dcache, but
 381                          * emulated DMA either goes through the dcache as
 382                          * normal writes, or the host kernel has handled dcache
 383                          * coherence. */
 384                         break;
 385
 386                 case OP_31_XOP_LWBRX:
 387                         rt = get_rt(inst);
 388                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 389                         break;
 390
 391                 case OP_31_XOP_TLBSYNC:
 392                         break;
 393
 394                 case OP_31_XOP_STWBRX:
 395                         rs = get_rs(inst);
 396                         ra = get_ra(inst);
 397                         rb = get_rb(inst);
 398
 399                         emulated = kvmppc_handle_store(run, vcpu,
 400                                                        kvmppc_get_gpr(vcpu, rs),
 401                                                        4, 0);
 402                         break;
 403
 404                 case OP_31_XOP_LHBRX:
 405                         rt = get_rt(inst);
 406                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 407                         break;
 408
 409                 case OP_31_XOP_STHBRX:
 410                         rs = get_rs(inst);
 411                         ra = get_ra(inst);
 412                         rb = get_rb(inst);
 413
 414                         emulated = kvmppc_handle_store(run, vcpu,
 415                                                        kvmppc_get_gpr(vcpu, rs),
 416                                                        2, 0);
 417                         break;
 418
 419                 default:
 420                         /* Attempt core-specific emulation below. */
 421                         emulated = EMULATE_FAIL;
 422                 }
 423                 break;
 424
 425         case OP_LWZ:
 426                 rt = get_rt(inst);
 427                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 428                 break;
 429
 430         case OP_LWZU:
 431                 ra = get_ra(inst);
 432                 rt = get_rt(inst);
 433                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 434                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 435                 break;
 436
 437         case OP_LBZ:
 438                 rt = get_rt(inst);
 439                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 440                 break;
 441
 442         case OP_LBZU:
 443                 ra = get_ra(inst);
 444                 rt = get_rt(inst);
 445                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 446                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 447                 break;
 448
 449         case OP_STW:
 450                 rs = get_rs(inst);
 451                 emulated = kvmppc_handle_store(run, vcpu,
 452                                                kvmppc_get_gpr(vcpu, rs),
 453                                                4, 1);
 454                 break;
 455
 456         case OP_STWU:
 457                 ra = get_ra(inst);
 458                 rs = get_rs(inst);
 459                 emulated = kvmppc_handle_store(run, vcpu,
 460                                                kvmppc_get_gpr(vcpu, rs),
 461                                                4, 1);
 462                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 463                 break;
 464
 465         case OP_STB:
 466                 rs = get_rs(inst);
 467                 emulated = kvmppc_handle_store(run, vcpu,
 468                                                kvmppc_get_gpr(vcpu, rs),
 469                                                1, 1);
 470                 break;
 471
 472         case OP_STBU:
 473                 ra = get_ra(inst);
 474                 rs = get_rs(inst);
 475                 emulated = kvmppc_handle_store(run, vcpu,
 476                                                kvmppc_get_gpr(vcpu, rs),
 477                                                1, 1);
 478                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 479                 break;
 480
 481         case OP_LHZ:
 482                 rt = get_rt(inst);
 483                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 484                 break;
 485
 486         case OP_LHZU:
 487                 ra = get_ra(inst);
 488                 rt = get_rt(inst);
 489                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 490                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 491                 break;
 492
 493         case OP_LHA:
 494                 rt = get_rt(inst);
 495                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 496                 break;
 497
 498         case OP_LHAU:
 499                 ra = get_ra(inst);
 500                 rt = get_rt(inst);
 501                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 502                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 503                 break;
 504
 505         case OP_STH:
 506                 rs = get_rs(inst);
 507                 emulated = kvmppc_handle_store(run, vcpu,
 508                                                kvmppc_get_gpr(vcpu, rs),
 509                                                2, 1);
 510                 break;
 511
 512         case OP_STHU:
 513                 ra = get_ra(inst);
 514                 rs = get_rs(inst);
 515                 emulated = kvmppc_handle_store(run, vcpu,
 516                                                kvmppc_get_gpr(vcpu, rs),
 517                                                2, 1);
 518                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 519                 break;
 520
 521         default:
 522                 emulated = EMULATE_FAIL;
 523         }
 524
 525         if (emulated == EMULATE_FAIL) {
 526                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 527                 if (emulated == EMULATE_AGAIN) {
 528                         advance = 0;
 529                 } else if (emulated == EMULATE_FAIL) {
 530                         advance = 0;
 531                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 532                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 533                         kvmppc_core_queue_program(vcpu, 0);
 534                 }
 535         }
 536
 537         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 538
 539         /* Advance past emulated instruction. */
 540         if (advance)
 541                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 542
 543         return emulated;
 544 }