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_LBZX      87
  39 #define OP_31_XOP_STWX      151
  40 #define OP_31_XOP_STBX      215
  41 #define OP_31_XOP_LBZUX     119
  42 #define OP_31_XOP_STBUX     247
  43 #define OP_31_XOP_LHZX      279
  44 #define OP_31_XOP_LHZUX     311
  45 #define OP_31_XOP_MFSPR     339
  46 #define OP_31_XOP_LHAX      343
  47 #define OP_31_XOP_STHX      407
  48 #define OP_31_XOP_STHUX     439
  49 #define OP_31_XOP_MTSPR     467
  50 #define OP_31_XOP_DCBI      470
  51 #define OP_31_XOP_LWBRX     534
  52 #define OP_31_XOP_TLBSYNC   566
  53 #define OP_31_XOP_STWBRX    662
  54 #define OP_31_XOP_LHBRX     790
  55 #define OP_31_XOP_STHBRX    918
  56
  57 #define OP_LWZ  32
  58 #define OP_LWZU 33
  59 #define OP_LBZ  34
  60 #define OP_LBZU 35
  61 #define OP_STW  36
  62 #define OP_STWU 37
  63 #define OP_STB  38
  64 #define OP_STBU 39
  65 #define OP_LHZ  40
  66 #define OP_LHZU 41
  67 #define OP_LHA  42
  68 #define OP_LHAU 43
  69 #define OP_STH  44
  70 #define OP_STHU 45
  71
  72 #ifdef CONFIG_PPC_BOOK3S
  73 static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
  74 {
  75         return 1;
  76 }
  77 #else
  78 static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
  79 {
  80         return vcpu->arch.tcr & TCR_DIE;
  81 }
  82 #endif
  83
  84 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  85 {
  86         unsigned long dec_nsec;
  87         unsigned long long dec_time;
  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_time = vcpu->arch.dec;
 108                 dec_time *= 1000;
 109                 do_div(dec_time, tb_ticks_per_usec);
 110                 dec_nsec = do_div(dec_time, NSEC_PER_SEC);
 111                 hrtimer_start(&vcpu->arch.dec_timer,
 112                         ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
 113                 vcpu->arch.dec_jiffies = get_tb();
 114         } else {
 115                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 116         }
 117 }
 118
 119 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 120 {
 121         u64 jd = tb - vcpu->arch.dec_jiffies;
 122         return vcpu->arch.dec - jd;
 123 }
 124
 125 /* XXX to do:
 126  * lhax
 127  * lhaux
 128  * lswx
 129  * lswi
 130  * stswx
 131  * stswi
 132  * lha
 133  * lhau
 134  * lmw
 135  * stmw
 136  *
 137  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 138  */
 139 /* XXX Should probably auto-generate instruction decoding for a particular core
 140  * from opcode tables in the future. */
 141 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 142 {
 143         u32 inst = kvmppc_get_last_inst(vcpu);
 144         u32 ea;
 145         int ra;
 146         int rb;
 147         int rs;
 148         int rt;
 149         int sprn;
 150         enum emulation_result emulated = EMULATE_DONE;
 151         int advance = 1;
 152
 153         /* this default type might be overwritten by subcategories */
 154         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 155
 156         pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 157
 158         switch (get_op(inst)) {
 159         case OP_TRAP:
 160 #ifdef CONFIG_PPC_BOOK3S
 161         case OP_TRAP_64:
 162                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 163 #else
 164                 kvmppc_core_queue_program(vcpu, vcpu->arch.esr | ESR_PTR);
 165 #endif
 166                 advance = 0;
 167                 break;
 168
 169         case 31:
 170                 switch (get_xop(inst)) {
 171
 172                 case OP_31_XOP_LWZX:
 173                         rt = get_rt(inst);
 174                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 175                         break;
 176
 177                 case OP_31_XOP_LBZX:
 178                         rt = get_rt(inst);
 179                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 180                         break;
 181
 182                 case OP_31_XOP_LBZUX:
 183                         rt = get_rt(inst);
 184                         ra = get_ra(inst);
 185                         rb = get_rb(inst);
 186
 187                         ea = kvmppc_get_gpr(vcpu, rb);
 188                         if (ra)
 189                                 ea += kvmppc_get_gpr(vcpu, ra);
 190
 191                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 192                         kvmppc_set_gpr(vcpu, ra, ea);
 193                         break;
 194
 195                 case OP_31_XOP_STWX:
 196                         rs = get_rs(inst);
 197                         emulated = kvmppc_handle_store(run, vcpu,
 198                                                        kvmppc_get_gpr(vcpu, rs),
 199                                                        4, 1);
 200                         break;
 201
 202                 case OP_31_XOP_STBX:
 203                         rs = get_rs(inst);
 204                         emulated = kvmppc_handle_store(run, vcpu,
 205                                                        kvmppc_get_gpr(vcpu, rs),
 206                                                        1, 1);
 207                         break;
 208
 209                 case OP_31_XOP_STBUX:
 210                         rs = get_rs(inst);
 211                         ra = get_ra(inst);
 212                         rb = get_rb(inst);
 213
 214                         ea = kvmppc_get_gpr(vcpu, rb);
 215                         if (ra)
 216                                 ea += kvmppc_get_gpr(vcpu, ra);
 217
 218                         emulated = kvmppc_handle_store(run, vcpu,
 219                                                        kvmppc_get_gpr(vcpu, rs),
 220                                                        1, 1);
 221                         kvmppc_set_gpr(vcpu, rs, ea);
 222                         break;
 223
 224                 case OP_31_XOP_LHAX:
 225                         rt = get_rt(inst);
 226                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 227                         break;
 228
 229                 case OP_31_XOP_LHZX:
 230                         rt = get_rt(inst);
 231                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 232                         break;
 233
 234                 case OP_31_XOP_LHZUX:
 235                         rt = get_rt(inst);
 236                         ra = get_ra(inst);
 237                         rb = get_rb(inst);
 238
 239                         ea = kvmppc_get_gpr(vcpu, rb);
 240                         if (ra)
 241                                 ea += kvmppc_get_gpr(vcpu, ra);
 242
 243                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 244                         kvmppc_set_gpr(vcpu, ra, ea);
 245                         break;
 246
 247                 case OP_31_XOP_MFSPR:
 248                         sprn = get_sprn(inst);
 249                         rt = get_rt(inst);
 250
 251                         switch (sprn) {
 252                         case SPRN_SRR0:
 253                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr0);
 254                                 break;
 255                         case SPRN_SRR1:
 256                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr1);
 257                                 break;
 258                         case SPRN_PVR:
 259                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
 260                         case SPRN_PIR:
 261                                 kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
 262                         case SPRN_MSSSR0:
 263                                 kvmppc_set_gpr(vcpu, rt, 0); break;
 264
 265                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 266                          * the guest can always access the real TB anyways.
 267                          * In fact, we probably will never see these traps. */
 268                         case SPRN_TBWL:
 269                                 kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
 270                         case SPRN_TBWU:
 271                                 kvmppc_set_gpr(vcpu, rt, get_tb()); break;
 272
 273                         case SPRN_SPRG0:
 274                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg0);
 275                                 break;
 276                         case SPRN_SPRG1:
 277                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg1);
 278                                 break;
 279                         case SPRN_SPRG2:
 280                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg2);
 281                                 break;
 282                         case SPRN_SPRG3:
 283                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg3);
 284                                 break;
 285                         /* Note: SPRG4-7 are user-readable, so we don't get
 286                          * a trap. */
 287
 288                         case SPRN_DEC:
 289                         {
 290                                 kvmppc_set_gpr(vcpu, rt,
 291                                                kvmppc_get_dec(vcpu, get_tb()));
 292                                 break;
 293                         }
 294                         default:
 295                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 296                                 if (emulated == EMULATE_FAIL) {
 297                                         printk("mfspr: unknown spr %x\n", sprn);
 298                                         kvmppc_set_gpr(vcpu, rt, 0);
 299                                 }
 300                                 break;
 301                         }
 302                         kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
 303                         break;
 304
 305                 case OP_31_XOP_STHX:
 306                         rs = get_rs(inst);
 307                         ra = get_ra(inst);
 308                         rb = get_rb(inst);
 309
 310                         emulated = kvmppc_handle_store(run, vcpu,
 311                                                        kvmppc_get_gpr(vcpu, rs),
 312                                                        2, 1);
 313                         break;
 314
 315                 case OP_31_XOP_STHUX:
 316                         rs = get_rs(inst);
 317                         ra = get_ra(inst);
 318                         rb = get_rb(inst);
 319
 320                         ea = kvmppc_get_gpr(vcpu, rb);
 321                         if (ra)
 322                                 ea += kvmppc_get_gpr(vcpu, ra);
 323
 324                         emulated = kvmppc_handle_store(run, vcpu,
 325                                                        kvmppc_get_gpr(vcpu, rs),
 326                                                        2, 1);
 327                         kvmppc_set_gpr(vcpu, ra, ea);
 328                         break;
 329
 330                 case OP_31_XOP_MTSPR:
 331                         sprn = get_sprn(inst);
 332                         rs = get_rs(inst);
 333                         switch (sprn) {
 334                         case SPRN_SRR0:
 335                                 vcpu->arch.shared->srr0 = kvmppc_get_gpr(vcpu, rs);
 336                                 break;
 337                         case SPRN_SRR1:
 338                                 vcpu->arch.shared->srr1 = kvmppc_get_gpr(vcpu, rs);
 339                                 break;
 340
 341                         /* XXX We need to context-switch the timebase for
 342                          * watchdog and FIT. */
 343                         case SPRN_TBWL: break;
 344                         case SPRN_TBWU: break;
 345
 346                         case SPRN_MSSSR0: break;
 347
 348                         case SPRN_DEC:
 349                                 vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
 350                                 kvmppc_emulate_dec(vcpu);
 351                                 break;
 352
 353                         case SPRN_SPRG0:
 354                                 vcpu->arch.shared->sprg0 = kvmppc_get_gpr(vcpu, rs);
 355                                 break;
 356                         case SPRN_SPRG1:
 357                                 vcpu->arch.shared->sprg1 = kvmppc_get_gpr(vcpu, rs);
 358                                 break;
 359                         case SPRN_SPRG2:
 360                                 vcpu->arch.shared->sprg2 = kvmppc_get_gpr(vcpu, rs);
 361                                 break;
 362                         case SPRN_SPRG3:
 363                                 vcpu->arch.shared->sprg3 = kvmppc_get_gpr(vcpu, rs);
 364                                 break;
 365
 366                         default:
 367                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 368                                 if (emulated == EMULATE_FAIL)
 369                                         printk("mtspr: unknown spr %x\n", sprn);
 370                                 break;
 371                         }
 372                         kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
 373                         break;
 374
 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 }