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
  88         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  89 #ifdef CONFIG_PPC_BOOK3S
  90         /* mtdec lowers the interrupt line when positive. */
  91         kvmppc_core_dequeue_dec(vcpu);
  92
  93         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  94         if (vcpu->arch.dec & 0x80000000) {
  95                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  96                 kvmppc_core_queue_dec(vcpu);
  97                 return;
  98         }
  99 #endif
 100         if (kvmppc_dec_enabled(vcpu)) {
 101                 /* The decrementer ticks at the same rate as the timebase, so
 102                  * that's how we convert the guest DEC value to the number of
 103                  * host ticks. */
 104
 105                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 106                 dec_nsec = vcpu->arch.dec;
 107                 dec_nsec *= 1000;
 108                 dec_nsec /= tb_ticks_per_usec;
 109                 hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
 110                               HRTIMER_MODE_REL);
 111                 vcpu->arch.dec_jiffies = get_tb();
 112         } else {
 113                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 114         }
 115 }
 116
 117 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 118 {
 119         u64 jd = tb - vcpu->arch.dec_jiffies;
 120         return vcpu->arch.dec - jd;
 121 }
 122
 123 /* XXX to do:
 124  * lhax
 125  * lhaux
 126  * lswx
 127  * lswi
 128  * stswx
 129  * stswi
 130  * lha
 131  * lhau
 132  * lmw
 133  * stmw
 134  *
 135  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 136  */
 137 /* XXX Should probably auto-generate instruction decoding for a particular core
 138  * from opcode tables in the future. */
 139 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 140 {
 141         u32 inst = kvmppc_get_last_inst(vcpu);
 142         u32 ea;
 143         int ra;
 144         int rb;
 145         int rs;
 146         int rt;
 147         int sprn;
 148         enum emulation_result emulated = EMULATE_DONE;
 149         int advance = 1;
 150
 151         /* this default type might be overwritten by subcategories */
 152         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 153
 154         pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 155
 156         switch (get_op(inst)) {
 157         case OP_TRAP:
 158 #ifdef CONFIG_PPC_BOOK3S
 159         case OP_TRAP_64:
 160                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 161 #else
 162                 kvmppc_core_queue_program(vcpu, vcpu->arch.esr | ESR_PTR);
 163 #endif
 164                 advance = 0;
 165                 break;
 166
 167         case 31:
 168                 switch (get_xop(inst)) {
 169
 170                 case OP_31_XOP_LWZX:
 171                         rt = get_rt(inst);
 172                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 173                         break;
 174
 175                 case OP_31_XOP_LBZX:
 176                         rt = get_rt(inst);
 177                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 178                         break;
 179
 180                 case OP_31_XOP_LBZUX:
 181                         rt = get_rt(inst);
 182                         ra = get_ra(inst);
 183                         rb = get_rb(inst);
 184
 185                         ea = kvmppc_get_gpr(vcpu, rb);
 186                         if (ra)
 187                                 ea += kvmppc_get_gpr(vcpu, ra);
 188
 189                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 190                         kvmppc_set_gpr(vcpu, ra, ea);
 191                         break;
 192
 193                 case OP_31_XOP_STWX:
 194                         rs = get_rs(inst);
 195                         emulated = kvmppc_handle_store(run, vcpu,
 196                                                        kvmppc_get_gpr(vcpu, rs),
 197                                                        4, 1);
 198                         break;
 199
 200                 case OP_31_XOP_STBX:
 201                         rs = get_rs(inst);
 202                         emulated = kvmppc_handle_store(run, vcpu,
 203                                                        kvmppc_get_gpr(vcpu, rs),
 204                                                        1, 1);
 205                         break;
 206
 207                 case OP_31_XOP_STBUX:
 208                         rs = get_rs(inst);
 209                         ra = get_ra(inst);
 210                         rb = get_rb(inst);
 211
 212                         ea = kvmppc_get_gpr(vcpu, rb);
 213                         if (ra)
 214                                 ea += kvmppc_get_gpr(vcpu, ra);
 215
 216                         emulated = kvmppc_handle_store(run, vcpu,
 217                                                        kvmppc_get_gpr(vcpu, rs),
 218                                                        1, 1);
 219                         kvmppc_set_gpr(vcpu, rs, ea);
 220                         break;
 221
 222                 case OP_31_XOP_LHAX:
 223                         rt = get_rt(inst);
 224                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 225                         break;
 226
 227                 case OP_31_XOP_LHZX:
 228                         rt = get_rt(inst);
 229                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 230                         break;
 231
 232                 case OP_31_XOP_LHZUX:
 233                         rt = get_rt(inst);
 234                         ra = get_ra(inst);
 235                         rb = get_rb(inst);
 236
 237                         ea = kvmppc_get_gpr(vcpu, rb);
 238                         if (ra)
 239                                 ea += kvmppc_get_gpr(vcpu, ra);
 240
 241                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 242                         kvmppc_set_gpr(vcpu, ra, ea);
 243                         break;
 244
 245                 case OP_31_XOP_MFSPR:
 246                         sprn = get_sprn(inst);
 247                         rt = get_rt(inst);
 248
 249                         switch (sprn) {
 250                         case SPRN_SRR0:
 251                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr0);
 252                                 break;
 253                         case SPRN_SRR1:
 254                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr1);
 255                                 break;
 256                         case SPRN_PVR:
 257                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
 258                         case SPRN_PIR:
 259                                 kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
 260                         case SPRN_MSSSR0:
 261                                 kvmppc_set_gpr(vcpu, rt, 0); break;
 262
 263                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 264                          * the guest can always access the real TB anyways.
 265                          * In fact, we probably will never see these traps. */
 266                         case SPRN_TBWL:
 267                                 kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
 268                         case SPRN_TBWU:
 269                                 kvmppc_set_gpr(vcpu, rt, get_tb()); break;
 270
 271                         case SPRN_SPRG0:
 272                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg0);
 273                                 break;
 274                         case SPRN_SPRG1:
 275                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg1);
 276                                 break;
 277                         case SPRN_SPRG2:
 278                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg2);
 279                                 break;
 280                         case SPRN_SPRG3:
 281                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg3);
 282                                 break;
 283                         /* Note: SPRG4-7 are user-readable, so we don't get
 284                          * a trap. */
 285
 286                         case SPRN_DEC:
 287                         {
 288                                 kvmppc_set_gpr(vcpu, rt,
 289                                                kvmppc_get_dec(vcpu, get_tb()));
 290                                 break;
 291                         }
 292                         default:
 293                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 294                                 if (emulated == EMULATE_FAIL) {
 295                                         printk("mfspr: unknown spr %x\n", sprn);
 296                                         kvmppc_set_gpr(vcpu, rt, 0);
 297                                 }
 298                                 break;
 299                         }
 300                         kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
 301                         break;
 302
 303                 case OP_31_XOP_STHX:
 304                         rs = get_rs(inst);
 305                         ra = get_ra(inst);
 306                         rb = get_rb(inst);
 307
 308                         emulated = kvmppc_handle_store(run, vcpu,
 309                                                        kvmppc_get_gpr(vcpu, rs),
 310                                                        2, 1);
 311                         break;
 312
 313                 case OP_31_XOP_STHUX:
 314                         rs = get_rs(inst);
 315                         ra = get_ra(inst);
 316                         rb = get_rb(inst);
 317
 318                         ea = kvmppc_get_gpr(vcpu, rb);
 319                         if (ra)
 320                                 ea += kvmppc_get_gpr(vcpu, ra);
 321
 322                         emulated = kvmppc_handle_store(run, vcpu,
 323                                                        kvmppc_get_gpr(vcpu, rs),
 324                                                        2, 1);
 325                         kvmppc_set_gpr(vcpu, ra, ea);
 326                         break;
 327
 328                 case OP_31_XOP_MTSPR:
 329                         sprn = get_sprn(inst);
 330                         rs = get_rs(inst);
 331                         switch (sprn) {
 332                         case SPRN_SRR0:
 333                                 vcpu->arch.shared->srr0 = kvmppc_get_gpr(vcpu, rs);
 334                                 break;
 335                         case SPRN_SRR1:
 336                                 vcpu->arch.shared->srr1 = kvmppc_get_gpr(vcpu, rs);
 337                                 break;
 338
 339                         /* XXX We need to context-switch the timebase for
 340                          * watchdog and FIT. */
 341                         case SPRN_TBWL: break;
 342                         case SPRN_TBWU: break;
 343
 344                         case SPRN_MSSSR0: break;
 345
 346                         case SPRN_DEC:
 347                                 vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
 348                                 kvmppc_emulate_dec(vcpu);
 349                                 break;
 350
 351                         case SPRN_SPRG0:
 352                                 vcpu->arch.shared->sprg0 = kvmppc_get_gpr(vcpu, rs);
 353                                 break;
 354                         case SPRN_SPRG1:
 355                                 vcpu->arch.shared->sprg1 = kvmppc_get_gpr(vcpu, rs);
 356                                 break;
 357                         case SPRN_SPRG2:
 358                                 vcpu->arch.shared->sprg2 = kvmppc_get_gpr(vcpu, rs);
 359                                 break;
 360                         case SPRN_SPRG3:
 361                                 vcpu->arch.shared->sprg3 = kvmppc_get_gpr(vcpu, rs);
 362                                 break;
 363
 364                         default:
 365                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 366                                 if (emulated == EMULATE_FAIL)
 367                                         printk("mtspr: unknown spr %x\n", sprn);
 368                                 break;
 369                         }
 370                         kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
 371                         break;
 372
 373                 case OP_31_XOP_DCBI:
 374                         /* Do nothing. The guest is performing dcbi because
 375                          * hardware DMA is not snooped by the dcache, but
 376                          * emulated DMA either goes through the dcache as
 377                          * normal writes, or the host kernel has handled dcache
 378                          * coherence. */
 379                         break;
 380
 381                 case OP_31_XOP_LWBRX:
 382                         rt = get_rt(inst);
 383                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 384                         break;
 385
 386                 case OP_31_XOP_TLBSYNC:
 387                         break;
 388
 389                 case OP_31_XOP_STWBRX:
 390                         rs = get_rs(inst);
 391                         ra = get_ra(inst);
 392                         rb = get_rb(inst);
 393
 394                         emulated = kvmppc_handle_store(run, vcpu,
 395                                                        kvmppc_get_gpr(vcpu, rs),
 396                                                        4, 0);
 397                         break;
 398
 399                 case OP_31_XOP_LHBRX:
 400                         rt = get_rt(inst);
 401                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 402                         break;
 403
 404                 case OP_31_XOP_STHBRX:
 405                         rs = get_rs(inst);
 406                         ra = get_ra(inst);
 407                         rb = get_rb(inst);
 408
 409                         emulated = kvmppc_handle_store(run, vcpu,
 410                                                        kvmppc_get_gpr(vcpu, rs),
 411                                                        2, 0);
 412                         break;
 413
 414                 default:
 415                         /* Attempt core-specific emulation below. */
 416                         emulated = EMULATE_FAIL;
 417                 }
 418                 break;
 419
 420         case OP_LWZ:
 421                 rt = get_rt(inst);
 422                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 423                 break;
 424
 425         case OP_LWZU:
 426                 ra = get_ra(inst);
 427                 rt = get_rt(inst);
 428                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 429                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 430                 break;
 431
 432         case OP_LBZ:
 433                 rt = get_rt(inst);
 434                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 435                 break;
 436
 437         case OP_LBZU:
 438                 ra = get_ra(inst);
 439                 rt = get_rt(inst);
 440                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 441                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 442                 break;
 443
 444         case OP_STW:
 445                 rs = get_rs(inst);
 446                 emulated = kvmppc_handle_store(run, vcpu,
 447                                                kvmppc_get_gpr(vcpu, rs),
 448                                                4, 1);
 449                 break;
 450
 451         case OP_STWU:
 452                 ra = get_ra(inst);
 453                 rs = get_rs(inst);
 454                 emulated = kvmppc_handle_store(run, vcpu,
 455                                                kvmppc_get_gpr(vcpu, rs),
 456                                                4, 1);
 457                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 458                 break;
 459
 460         case OP_STB:
 461                 rs = get_rs(inst);
 462                 emulated = kvmppc_handle_store(run, vcpu,
 463                                                kvmppc_get_gpr(vcpu, rs),
 464                                                1, 1);
 465                 break;
 466
 467         case OP_STBU:
 468                 ra = get_ra(inst);
 469                 rs = get_rs(inst);
 470                 emulated = kvmppc_handle_store(run, vcpu,
 471                                                kvmppc_get_gpr(vcpu, rs),
 472                                                1, 1);
 473                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 474                 break;
 475
 476         case OP_LHZ:
 477                 rt = get_rt(inst);
 478                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 479                 break;
 480
 481         case OP_LHZU:
 482                 ra = get_ra(inst);
 483                 rt = get_rt(inst);
 484                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 485                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 486                 break;
 487
 488         case OP_LHA:
 489                 rt = get_rt(inst);
 490                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 491                 break;
 492
 493         case OP_LHAU:
 494                 ra = get_ra(inst);
 495                 rt = get_rt(inst);
 496                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 497                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 498                 break;
 499
 500         case OP_STH:
 501                 rs = get_rs(inst);
 502                 emulated = kvmppc_handle_store(run, vcpu,
 503                                                kvmppc_get_gpr(vcpu, rs),
 504                                                2, 1);
 505                 break;
 506
 507         case OP_STHU:
 508                 ra = get_ra(inst);
 509                 rs = get_rs(inst);
 510                 emulated = kvmppc_handle_store(run, vcpu,
 511                                                kvmppc_get_gpr(vcpu, rs),
 512                                                2, 1);
 513                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 514                 break;
 515
 516         default:
 517                 emulated = EMULATE_FAIL;
 518         }
 519
 520         if (emulated == EMULATE_FAIL) {
 521                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 522                 if (emulated == EMULATE_AGAIN) {
 523                         advance = 0;
 524                 } else if (emulated == EMULATE_FAIL) {
 525                         advance = 0;
 526                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 527                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 528                         kvmppc_core_queue_program(vcpu, 0);
 529                 }
 530         }
 531
 532         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 533
 534         /* Advance past emulated instruction. */
 535         if (advance)
 536                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 537
 538         return emulated;
 539 }