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