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  *
  17  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  18  */
  19
  20 #include <linux/jiffies.h>
  21 #include <linux/hrtimer.h>
  22 #include <linux/types.h>
  23 #include <linux/string.h>
  24 #include <linux/kvm_host.h>
  25
  26 #include <asm/reg.h>
  27 #include <asm/time.h>
  28 #include <asm/byteorder.h>
  29 #include <asm/kvm_ppc.h>
  30 #include <asm/disassemble.h>
  31 #include "timing.h"
  32 #include "trace.h"
  33
  34 #define OP_TRAP 3
  35 #define OP_TRAP_64 2
  36
  37 #define OP_31_XOP_LWZX      23
  38 #define OP_31_XOP_DCBF      86
  39 #define OP_31_XOP_LBZX      87
  40 #define OP_31_XOP_STWX      151
  41 #define OP_31_XOP_STBX      215
  42 #define OP_31_XOP_LBZUX     119
  43 #define OP_31_XOP_STBUX     247
  44 #define OP_31_XOP_LHZX      279
  45 #define OP_31_XOP_LHZUX     311
  46 #define OP_31_XOP_MFSPR     339
  47 #define OP_31_XOP_LHAX      343
  48 #define OP_31_XOP_STHX      407
  49 #define OP_31_XOP_STHUX     439
  50 #define OP_31_XOP_MTSPR     467
  51 #define OP_31_XOP_DCBI      470
  52 #define OP_31_XOP_LWBRX     534
  53 #define OP_31_XOP_TLBSYNC   566
  54 #define OP_31_XOP_STWBRX    662
  55 #define OP_31_XOP_LHBRX     790
  56 #define OP_31_XOP_STHBRX    918
  57
  58 #define OP_LWZ  32
  59 #define OP_LWZU 33
  60 #define OP_LBZ  34
  61 #define OP_LBZU 35
  62 #define OP_STW  36
  63 #define OP_STWU 37
  64 #define OP_STB  38
  65 #define OP_STBU 39
  66 #define OP_LHZ  40
  67 #define OP_LHZU 41
  68 #define OP_LHA  42
  69 #define OP_LHAU 43
  70 #define OP_STH  44
  71 #define OP_STHU 45
  72
  73 #ifdef CONFIG_PPC_BOOK3S
  74 static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
  75 {
  76         return 1;
  77 }
  78 #else
  79 static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
  80 {
  81         return vcpu->arch.tcr & TCR_DIE;
  82 }
  83 #endif
  84
  85 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  86 {
  87         unsigned long dec_nsec;
  88
  89         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  90 #ifdef CONFIG_PPC_BOOK3S
  91         /* mtdec lowers the interrupt line when positive. */
  92         kvmppc_core_dequeue_dec(vcpu);
  93
  94         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  95         if (vcpu->arch.dec & 0x80000000) {
  96                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  97                 kvmppc_core_queue_dec(vcpu);
  98                 return;
  99         }
 100 #endif
 101         if (kvmppc_dec_enabled(vcpu)) {
 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                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 107                 dec_nsec = vcpu->arch.dec;
 108                 dec_nsec *= 1000;
 109                 dec_nsec /= tb_ticks_per_usec;
 110                 hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
 111                               HRTIMER_MODE_REL);
 112                 vcpu->arch.dec_jiffies = get_tb();
 113         } else {
 114                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 115         }
 116 }
 117
 118 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 119 {
 120         u64 jd = tb - vcpu->arch.dec_jiffies;
 121         return vcpu->arch.dec - jd;
 122 }
 123
 124 /* XXX to do:
 125  * lhax
 126  * lhaux
 127  * lswx
 128  * lswi
 129  * stswx
 130  * stswi
 131  * lha
 132  * lhau
 133  * lmw
 134  * stmw
 135  *
 136  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 137  */
 138 /* XXX Should probably auto-generate instruction decoding for a particular core
 139  * from opcode tables in the future. */
 140 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 141 {
 142         u32 inst = kvmppc_get_last_inst(vcpu);
 143         u32 ea;
 144         int ra;
 145         int rb;
 146         int rs;
 147         int rt;
 148         int sprn;
 149         enum emulation_result emulated = EMULATE_DONE;
 150         int advance = 1;
 151
 152         /* this default type might be overwritten by subcategories */
 153         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 154
 155         pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 156
 157         switch (get_op(inst)) {
 158         case OP_TRAP:
 159 #ifdef CONFIG_PPC_BOOK3S
 160         case OP_TRAP_64:
 161                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 162 #else
 163                 kvmppc_core_queue_program(vcpu, vcpu->arch.esr | ESR_PTR);
 164 #endif
 165                 advance = 0;
 166                 break;
 167
 168         case 31:
 169                 switch (get_xop(inst)) {
 170
 171                 case OP_31_XOP_LWZX:
 172                         rt = get_rt(inst);
 173                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 174                         break;
 175
 176                 case OP_31_XOP_LBZX:
 177                         rt = get_rt(inst);
 178                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 179                         break;
 180
 181                 case OP_31_XOP_LBZUX:
 182                         rt = get_rt(inst);
 183                         ra = get_ra(inst);
 184                         rb = get_rb(inst);
 185
 186                         ea = kvmppc_get_gpr(vcpu, rb);
 187                         if (ra)
 188                                 ea += kvmppc_get_gpr(vcpu, ra);
 189
 190                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 191                         kvmppc_set_gpr(vcpu, ra, ea);
 192                         break;
 193
 194                 case OP_31_XOP_STWX:
 195                         rs = get_rs(inst);
 196                         emulated = kvmppc_handle_store(run, vcpu,
 197                                                        kvmppc_get_gpr(vcpu, rs),
 198                                                        4, 1);
 199                         break;
 200
 201                 case OP_31_XOP_STBX:
 202                         rs = get_rs(inst);
 203                         emulated = kvmppc_handle_store(run, vcpu,
 204                                                        kvmppc_get_gpr(vcpu, rs),
 205                                                        1, 1);
 206                         break;
 207
 208                 case OP_31_XOP_STBUX:
 209                         rs = get_rs(inst);
 210                         ra = get_ra(inst);
 211                         rb = get_rb(inst);
 212
 213                         ea = kvmppc_get_gpr(vcpu, rb);
 214                         if (ra)
 215                                 ea += kvmppc_get_gpr(vcpu, ra);
 216
 217                         emulated = kvmppc_handle_store(run, vcpu,
 218                                                        kvmppc_get_gpr(vcpu, rs),
 219                                                        1, 1);
 220                         kvmppc_set_gpr(vcpu, rs, ea);
 221                         break;
 222
 223                 case OP_31_XOP_LHAX:
 224                         rt = get_rt(inst);
 225                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 226                         break;
 227
 228                 case OP_31_XOP_LHZX:
 229                         rt = get_rt(inst);
 230                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 231                         break;
 232
 233                 case OP_31_XOP_LHZUX:
 234                         rt = get_rt(inst);
 235                         ra = get_ra(inst);
 236                         rb = get_rb(inst);
 237
 238                         ea = kvmppc_get_gpr(vcpu, rb);
 239                         if (ra)
 240                                 ea += kvmppc_get_gpr(vcpu, ra);
 241
 242                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 243                         kvmppc_set_gpr(vcpu, ra, ea);
 244                         break;
 245
 246                 case OP_31_XOP_MFSPR:
 247                         sprn = get_sprn(inst);
 248                         rt = get_rt(inst);
 249
 250                         switch (sprn) {
 251                         case SPRN_SRR0:
 252                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr0);
 253                                 break;
 254                         case SPRN_SRR1:
 255                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr1);
 256                                 break;
 257                         case SPRN_PVR:
 258                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
 259                         case SPRN_PIR:
 260                                 kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
 261                         case SPRN_MSSSR0:
 262                                 kvmppc_set_gpr(vcpu, rt, 0); break;
 263
 264                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 265                          * the guest can always access the real TB anyways.
 266                          * In fact, we probably will never see these traps. */
 267                         case SPRN_TBWL:
 268                                 kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
 269                         case SPRN_TBWU:
 270                                 kvmppc_set_gpr(vcpu, rt, get_tb()); break;
 271
 272                         case SPRN_SPRG0:
 273                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg0);
 274                                 break;
 275                         case SPRN_SPRG1:
 276                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg1);
 277                                 break;
 278                         case SPRN_SPRG2:
 279                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg2);
 280                                 break;
 281                         case SPRN_SPRG3:
 282                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg3);
 283                                 break;
 284                         /* Note: SPRG4-7 are user-readable, so we don't get
 285                          * a trap. */
 286
 287                         case SPRN_DEC:
 288                         {
 289                                 kvmppc_set_gpr(vcpu, rt,
 290                                                kvmppc_get_dec(vcpu, get_tb()));
 291                                 break;
 292                         }
 293                         default:
 294                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 295                                 if (emulated == EMULATE_FAIL) {
 296                                         printk("mfspr: unknown spr %x\n", sprn);
 297                                         kvmppc_set_gpr(vcpu, rt, 0);
 298                                 }
 299                                 break;
 300                         }
 301                         kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
 302                         break;
 303
 304                 case OP_31_XOP_STHX:
 305                         rs = get_rs(inst);
 306                         ra = get_ra(inst);
 307                         rb = get_rb(inst);
 308
 309                         emulated = kvmppc_handle_store(run, vcpu,
 310                                                        kvmppc_get_gpr(vcpu, rs),
 311                                                        2, 1);
 312                         break;
 313
 314                 case OP_31_XOP_STHUX:
 315                         rs = get_rs(inst);
 316                         ra = get_ra(inst);
 317                         rb = get_rb(inst);
 318
 319                         ea = kvmppc_get_gpr(vcpu, rb);
 320                         if (ra)
 321                                 ea += kvmppc_get_gpr(vcpu, ra);
 322
 323                         emulated = kvmppc_handle_store(run, vcpu,
 324                                                        kvmppc_get_gpr(vcpu, rs),
 325                                                        2, 1);
 326                         kvmppc_set_gpr(vcpu, ra, ea);
 327                         break;
 328
 329                 case OP_31_XOP_MTSPR:
 330                         sprn = get_sprn(inst);
 331                         rs = get_rs(inst);
 332                         switch (sprn) {
 333                         case SPRN_SRR0:
 334                                 vcpu->arch.shared->srr0 = kvmppc_get_gpr(vcpu, rs);
 335                                 break;
 336                         case SPRN_SRR1:
 337                                 vcpu->arch.shared->srr1 = kvmppc_get_gpr(vcpu, rs);
 338                                 break;
 339
 340                         /* XXX We need to context-switch the timebase for
 341                          * watchdog and FIT. */
 342                         case SPRN_TBWL: break;
 343                         case SPRN_TBWU: break;
 344
 345                         case SPRN_MSSSR0: break;
 346
 347                         case SPRN_DEC:
 348                                 vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
 349                                 kvmppc_emulate_dec(vcpu);
 350                                 break;
 351
 352                         case SPRN_SPRG0:
 353                                 vcpu->arch.shared->sprg0 = kvmppc_get_gpr(vcpu, rs);
 354                                 break;
 355                         case SPRN_SPRG1:
 356                                 vcpu->arch.shared->sprg1 = kvmppc_get_gpr(vcpu, rs);
 357                                 break;
 358                         case SPRN_SPRG2:
 359                                 vcpu->arch.shared->sprg2 = kvmppc_get_gpr(vcpu, rs);
 360                                 break;
 361                         case SPRN_SPRG3:
 362                                 vcpu->arch.shared->sprg3 = kvmppc_get_gpr(vcpu, rs);
 363                                 break;
 364
 365                         default:
 366                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 367                                 if (emulated == EMULATE_FAIL)
 368                                         printk("mtspr: unknown spr %x\n", sprn);
 369                                 break;
 370                         }
 371                         kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
 372                         break;
 373
 374                 case OP_31_XOP_DCBF:
 375                 case OP_31_XOP_DCBI:
 376                         /* Do nothing. The guest is performing dcbi because
 377                          * hardware DMA is not snooped by the dcache, but
 378                          * emulated DMA either goes through the dcache as
 379                          * normal writes, or the host kernel has handled dcache
 380                          * coherence. */
 381                         break;
 382
 383                 case OP_31_XOP_LWBRX:
 384                         rt = get_rt(inst);
 385                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 386                         break;
 387
 388                 case OP_31_XOP_TLBSYNC:
 389                         break;
 390
 391                 case OP_31_XOP_STWBRX:
 392                         rs = get_rs(inst);
 393                         ra = get_ra(inst);
 394                         rb = get_rb(inst);
 395
 396                         emulated = kvmppc_handle_store(run, vcpu,
 397                                                        kvmppc_get_gpr(vcpu, rs),
 398                                                        4, 0);
 399                         break;
 400
 401                 case OP_31_XOP_LHBRX:
 402                         rt = get_rt(inst);
 403                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 404                         break;
 405
 406                 case OP_31_XOP_STHBRX:
 407                         rs = get_rs(inst);
 408                         ra = get_ra(inst);
 409                         rb = get_rb(inst);
 410
 411                         emulated = kvmppc_handle_store(run, vcpu,
 412                                                        kvmppc_get_gpr(vcpu, rs),
 413                                                        2, 0);
 414                         break;
 415
 416                 default:
 417                         /* Attempt core-specific emulation below. */
 418                         emulated = EMULATE_FAIL;
 419                 }
 420                 break;
 421
 422         case OP_LWZ:
 423                 rt = get_rt(inst);
 424                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 425                 break;
 426
 427         case OP_LWZU:
 428                 ra = get_ra(inst);
 429                 rt = get_rt(inst);
 430                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 431                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 432                 break;
 433
 434         case OP_LBZ:
 435                 rt = get_rt(inst);
 436                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 437                 break;
 438
 439         case OP_LBZU:
 440                 ra = get_ra(inst);
 441                 rt = get_rt(inst);
 442                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 443                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 444                 break;
 445
 446         case OP_STW:
 447                 rs = get_rs(inst);
 448                 emulated = kvmppc_handle_store(run, vcpu,
 449                                                kvmppc_get_gpr(vcpu, rs),
 450                                                4, 1);
 451                 break;
 452
 453         case OP_STWU:
 454                 ra = get_ra(inst);
 455                 rs = get_rs(inst);
 456                 emulated = kvmppc_handle_store(run, vcpu,
 457                                                kvmppc_get_gpr(vcpu, rs),
 458                                                4, 1);
 459                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 460                 break;
 461
 462         case OP_STB:
 463                 rs = get_rs(inst);
 464                 emulated = kvmppc_handle_store(run, vcpu,
 465                                                kvmppc_get_gpr(vcpu, rs),
 466                                                1, 1);
 467                 break;
 468
 469         case OP_STBU:
 470                 ra = get_ra(inst);
 471                 rs = get_rs(inst);
 472                 emulated = kvmppc_handle_store(run, vcpu,
 473                                                kvmppc_get_gpr(vcpu, rs),
 474                                                1, 1);
 475                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 476                 break;
 477
 478         case OP_LHZ:
 479                 rt = get_rt(inst);
 480                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 481                 break;
 482
 483         case OP_LHZU:
 484                 ra = get_ra(inst);
 485                 rt = get_rt(inst);
 486                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 487                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 488                 break;
 489
 490         case OP_LHA:
 491                 rt = get_rt(inst);
 492                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 493                 break;
 494
 495         case OP_LHAU:
 496                 ra = get_ra(inst);
 497                 rt = get_rt(inst);
 498                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 499                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 500                 break;
 501
 502         case OP_STH:
 503                 rs = get_rs(inst);
 504                 emulated = kvmppc_handle_store(run, vcpu,
 505                                                kvmppc_get_gpr(vcpu, rs),
 506                                                2, 1);
 507                 break;
 508
 509         case OP_STHU:
 510                 ra = get_ra(inst);
 511                 rs = get_rs(inst);
 512                 emulated = kvmppc_handle_store(run, vcpu,
 513                                                kvmppc_get_gpr(vcpu, rs),
 514                                                2, 1);
 515                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 516                 break;
 517
 518         default:
 519                 emulated = EMULATE_FAIL;
 520         }
 521
 522         if (emulated == EMULATE_FAIL) {
 523                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 524                 if (emulated == EMULATE_AGAIN) {
 525                         advance = 0;
 526                 } else if (emulated == EMULATE_FAIL) {
 527                         advance = 0;
 528                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 529                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 530                         kvmppc_core_queue_program(vcpu, 0);
 531                 }
 532         }
 533
 534         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 535
 536         /* Advance past emulated instruction. */
 537         if (advance)
 538                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 539
 540         return emulated;
 541 }