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_PPC64
  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_PPC64
  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(KERN_INFO "Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 149
 150         /* Try again next time */
 151         if (inst == KVM_INST_FETCH_FAILED)
 152                 return EMULATE_DONE;
 153
 154         switch (get_op(inst)) {
 155         case OP_TRAP:
 156 #ifdef CONFIG_PPC64
 157         case OP_TRAP_64:
 158                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 159 #else
 160                 kvmppc_core_queue_program(vcpu, vcpu->arch.esr | ESR_PTR);
 161 #endif
 162                 advance = 0;
 163                 break;
 164
 165         case 31:
 166                 switch (get_xop(inst)) {
 167
 168                 case OP_31_XOP_LWZX:
 169                         rt = get_rt(inst);
 170                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 171                         break;
 172
 173                 case OP_31_XOP_LBZX:
 174                         rt = get_rt(inst);
 175                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 176                         break;
 177
 178                 case OP_31_XOP_LBZUX:
 179                         rt = get_rt(inst);
 180                         ra = get_ra(inst);
 181                         rb = get_rb(inst);
 182
 183                         ea = kvmppc_get_gpr(vcpu, rb);
 184                         if (ra)
 185                                 ea += kvmppc_get_gpr(vcpu, ra);
 186
 187                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 188                         kvmppc_set_gpr(vcpu, ra, ea);
 189                         break;
 190
 191                 case OP_31_XOP_STWX:
 192                         rs = get_rs(inst);
 193                         emulated = kvmppc_handle_store(run, vcpu,
 194                                                        kvmppc_get_gpr(vcpu, rs),
 195                                                        4, 1);
 196                         break;
 197
 198                 case OP_31_XOP_STBX:
 199                         rs = get_rs(inst);
 200                         emulated = kvmppc_handle_store(run, vcpu,
 201                                                        kvmppc_get_gpr(vcpu, rs),
 202                                                        1, 1);
 203                         break;
 204
 205                 case OP_31_XOP_STBUX:
 206                         rs = get_rs(inst);
 207                         ra = get_ra(inst);
 208                         rb = get_rb(inst);
 209
 210                         ea = kvmppc_get_gpr(vcpu, rb);
 211                         if (ra)
 212                                 ea += kvmppc_get_gpr(vcpu, ra);
 213
 214                         emulated = kvmppc_handle_store(run, vcpu,
 215                                                        kvmppc_get_gpr(vcpu, rs),
 216                                                        1, 1);
 217                         kvmppc_set_gpr(vcpu, rs, ea);
 218                         break;
 219
 220                 case OP_31_XOP_LHAX:
 221                         rt = get_rt(inst);
 222                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 223                         break;
 224
 225                 case OP_31_XOP_LHZX:
 226                         rt = get_rt(inst);
 227                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 228                         break;
 229
 230                 case OP_31_XOP_LHZUX:
 231                         rt = get_rt(inst);
 232                         ra = get_ra(inst);
 233                         rb = get_rb(inst);
 234
 235                         ea = kvmppc_get_gpr(vcpu, rb);
 236                         if (ra)
 237                                 ea += kvmppc_get_gpr(vcpu, ra);
 238
 239                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 240                         kvmppc_set_gpr(vcpu, ra, ea);
 241                         break;
 242
 243                 case OP_31_XOP_MFSPR:
 244                         sprn = get_sprn(inst);
 245                         rt = get_rt(inst);
 246
 247                         switch (sprn) {
 248                         case SPRN_SRR0:
 249                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.srr0); break;
 250                         case SPRN_SRR1:
 251                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.srr1); break;
 252                         case SPRN_PVR:
 253                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
 254                         case SPRN_PIR:
 255                                 kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
 256                         case SPRN_MSSSR0:
 257                                 kvmppc_set_gpr(vcpu, rt, 0); break;
 258
 259                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 260                          * the guest can always access the real TB anyways.
 261                          * In fact, we probably will never see these traps. */
 262                         case SPRN_TBWL:
 263                                 kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
 264                         case SPRN_TBWU:
 265                                 kvmppc_set_gpr(vcpu, rt, get_tb()); break;
 266
 267                         case SPRN_SPRG0:
 268                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg0); break;
 269                         case SPRN_SPRG1:
 270                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg1); break;
 271                         case SPRN_SPRG2:
 272                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg2); break;
 273                         case SPRN_SPRG3:
 274                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg3); break;
 275                         /* Note: SPRG4-7 are user-readable, so we don't get
 276                          * a trap. */
 277
 278                         case SPRN_DEC:
 279                         {
 280                                 u64 jd = get_tb() - vcpu->arch.dec_jiffies;
 281                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.dec - jd);
 282                                 pr_debug(KERN_INFO "mfDEC: %x - %llx = %lx\n",
 283                                          vcpu->arch.dec, jd,
 284                                          kvmppc_get_gpr(vcpu, rt));
 285                                 break;
 286                         }
 287                         default:
 288                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 289                                 if (emulated == EMULATE_FAIL) {
 290                                         printk("mfspr: unknown spr %x\n", sprn);
 291                                         kvmppc_set_gpr(vcpu, rt, 0);
 292                                 }
 293                                 break;
 294                         }
 295                         break;
 296
 297                 case OP_31_XOP_STHX:
 298                         rs = get_rs(inst);
 299                         ra = get_ra(inst);
 300                         rb = get_rb(inst);
 301
 302                         emulated = kvmppc_handle_store(run, vcpu,
 303                                                        kvmppc_get_gpr(vcpu, rs),
 304                                                        2, 1);
 305                         break;
 306
 307                 case OP_31_XOP_STHUX:
 308                         rs = get_rs(inst);
 309                         ra = get_ra(inst);
 310                         rb = get_rb(inst);
 311
 312                         ea = kvmppc_get_gpr(vcpu, rb);
 313                         if (ra)
 314                                 ea += kvmppc_get_gpr(vcpu, ra);
 315
 316                         emulated = kvmppc_handle_store(run, vcpu,
 317                                                        kvmppc_get_gpr(vcpu, rs),
 318                                                        2, 1);
 319                         kvmppc_set_gpr(vcpu, ra, ea);
 320                         break;
 321
 322                 case OP_31_XOP_MTSPR:
 323                         sprn = get_sprn(inst);
 324                         rs = get_rs(inst);
 325                         switch (sprn) {
 326                         case SPRN_SRR0:
 327                                 vcpu->arch.srr0 = kvmppc_get_gpr(vcpu, rs); break;
 328                         case SPRN_SRR1:
 329                                 vcpu->arch.srr1 = kvmppc_get_gpr(vcpu, rs); break;
 330
 331                         /* XXX We need to context-switch the timebase for
 332                          * watchdog and FIT. */
 333                         case SPRN_TBWL: break;
 334                         case SPRN_TBWU: break;
 335
 336                         case SPRN_MSSSR0: break;
 337
 338                         case SPRN_DEC:
 339                                 vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
 340                                 kvmppc_emulate_dec(vcpu);
 341                                 break;
 342
 343                         case SPRN_SPRG0:
 344                                 vcpu->arch.sprg0 = kvmppc_get_gpr(vcpu, rs); break;
 345                         case SPRN_SPRG1:
 346                                 vcpu->arch.sprg1 = kvmppc_get_gpr(vcpu, rs); break;
 347                         case SPRN_SPRG2:
 348                                 vcpu->arch.sprg2 = kvmppc_get_gpr(vcpu, rs); break;
 349                         case SPRN_SPRG3:
 350                                 vcpu->arch.sprg3 = kvmppc_get_gpr(vcpu, rs); break;
 351
 352                         default:
 353                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 354                                 if (emulated == EMULATE_FAIL)
 355                                         printk("mtspr: unknown spr %x\n", sprn);
 356                                 break;
 357                         }
 358                         break;
 359
 360                 case OP_31_XOP_DCBI:
 361                         /* Do nothing. The guest is performing dcbi because
 362                          * hardware DMA is not snooped by the dcache, but
 363                          * emulated DMA either goes through the dcache as
 364                          * normal writes, or the host kernel has handled dcache
 365                          * coherence. */
 366                         break;
 367
 368                 case OP_31_XOP_LWBRX:
 369                         rt = get_rt(inst);
 370                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 371                         break;
 372
 373                 case OP_31_XOP_TLBSYNC:
 374                         break;
 375
 376                 case OP_31_XOP_STWBRX:
 377                         rs = get_rs(inst);
 378                         ra = get_ra(inst);
 379                         rb = get_rb(inst);
 380
 381                         emulated = kvmppc_handle_store(run, vcpu,
 382                                                        kvmppc_get_gpr(vcpu, rs),
 383                                                        4, 0);
 384                         break;
 385
 386                 case OP_31_XOP_LHBRX:
 387                         rt = get_rt(inst);
 388                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 389                         break;
 390
 391                 case OP_31_XOP_STHBRX:
 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                                                        2, 0);
 399                         break;
 400
 401                 default:
 402                         /* Attempt core-specific emulation below. */
 403                         emulated = EMULATE_FAIL;
 404                 }
 405                 break;
 406
 407         case OP_LWZ:
 408                 rt = get_rt(inst);
 409                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 410                 break;
 411
 412         case OP_LWZU:
 413                 ra = get_ra(inst);
 414                 rt = get_rt(inst);
 415                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 416                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 417                 break;
 418
 419         case OP_LBZ:
 420                 rt = get_rt(inst);
 421                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 422                 break;
 423
 424         case OP_LBZU:
 425                 ra = get_ra(inst);
 426                 rt = get_rt(inst);
 427                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 428                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 429                 break;
 430
 431         case OP_STW:
 432                 rs = get_rs(inst);
 433                 emulated = kvmppc_handle_store(run, vcpu,
 434                                                kvmppc_get_gpr(vcpu, rs),
 435                                                4, 1);
 436                 break;
 437
 438         case OP_STWU:
 439                 ra = get_ra(inst);
 440                 rs = get_rs(inst);
 441                 emulated = kvmppc_handle_store(run, vcpu,
 442                                                kvmppc_get_gpr(vcpu, rs),
 443                                                4, 1);
 444                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 445                 break;
 446
 447         case OP_STB:
 448                 rs = get_rs(inst);
 449                 emulated = kvmppc_handle_store(run, vcpu,
 450                                                kvmppc_get_gpr(vcpu, rs),
 451                                                1, 1);
 452                 break;
 453
 454         case OP_STBU:
 455                 ra = get_ra(inst);
 456                 rs = get_rs(inst);
 457                 emulated = kvmppc_handle_store(run, vcpu,
 458                                                kvmppc_get_gpr(vcpu, rs),
 459                                                1, 1);
 460                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 461                 break;
 462
 463         case OP_LHZ:
 464                 rt = get_rt(inst);
 465                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 466                 break;
 467
 468         case OP_LHZU:
 469                 ra = get_ra(inst);
 470                 rt = get_rt(inst);
 471                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 472                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 473                 break;
 474
 475         case OP_LHA:
 476                 rt = get_rt(inst);
 477                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 478                 break;
 479
 480         case OP_LHAU:
 481                 ra = get_ra(inst);
 482                 rt = get_rt(inst);
 483                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 484                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 485                 break;
 486
 487         case OP_STH:
 488                 rs = get_rs(inst);
 489                 emulated = kvmppc_handle_store(run, vcpu,
 490                                                kvmppc_get_gpr(vcpu, rs),
 491                                                2, 1);
 492                 break;
 493
 494         case OP_STHU:
 495                 ra = get_ra(inst);
 496                 rs = get_rs(inst);
 497                 emulated = kvmppc_handle_store(run, vcpu,
 498                                                kvmppc_get_gpr(vcpu, rs),
 499                                                2, 1);
 500                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 501                 break;
 502
 503         default:
 504                 emulated = EMULATE_FAIL;
 505         }
 506
 507         if (emulated == EMULATE_FAIL) {
 508                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 509                 if (emulated == EMULATE_AGAIN) {
 510                         advance = 0;
 511                 } else if (emulated == EMULATE_FAIL) {
 512                         advance = 0;
 513                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 514                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 515                         kvmppc_core_queue_program(vcpu, 0);
 516                 }
 517         }
 518
 519         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 520
 521         /* Advance past emulated instruction. */
 522         if (advance)
 523                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 524
 525         return emulated;
 526 }