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  * Copyright 2011 Freescale Semiconductor, Inc.
  17  *
  18  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  19  */
  20
  21 #include <linux/jiffies.h>
  22 #include <linux/hrtimer.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/kvm_host.h>
  26
  27 #include <asm/reg.h>
  28 #include <asm/time.h>
  29 #include <asm/byteorder.h>
  30 #include <asm/kvm_ppc.h>
  31 #include <asm/disassemble.h>
  32 #include "timing.h"
  33 #include "trace.h"
  34
  35 #define OP_TRAP 3
  36 #define OP_TRAP_64 2
  37
  38 #define OP_31_XOP_LWZX      23
  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 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  74 {
  75         unsigned long dec_nsec;
  76         unsigned long long dec_time;
  77
  78         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  79         hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  80
  81 #ifdef CONFIG_PPC_BOOK3S
  82         /* mtdec lowers the interrupt line when positive. */
  83         kvmppc_core_dequeue_dec(vcpu);
  84
  85         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  86         if (vcpu->arch.dec & 0x80000000) {
  87                 kvmppc_core_queue_dec(vcpu);
  88                 return;
  89         }
  90 #endif
  91
  92 #ifdef CONFIG_BOOKE
  93         /* On BOOKE, DEC = 0 is as good as decrementer not enabled */
  94         if (vcpu->arch.dec == 0)
  95                 return;
  96 #endif
  97
  98         /*
  99          * The decrementer ticks at the same rate as the timebase, so
 100          * that's how we convert the guest DEC value to the number of
 101          * host ticks.
 102          */
 103
 104         dec_time = vcpu->arch.dec;
 105         dec_time *= 1000;
 106         do_div(dec_time, tb_ticks_per_usec);
 107         dec_nsec = do_div(dec_time, NSEC_PER_SEC);
 108         hrtimer_start(&vcpu->arch.dec_timer,
 109                 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
 110         vcpu->arch.dec_jiffies = get_tb();
 111 }
 112
 113 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 114 {
 115         u64 jd = tb - vcpu->arch.dec_jiffies;
 116
 117 #ifdef CONFIG_BOOKE
 118         if (vcpu->arch.dec < jd)
 119                 return 0;
 120 #endif
 121
 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,
 165                                           vcpu->arch.shared->esr | ESR_PTR);
 166 #endif
 167                 advance = 0;
 168                 break;
 169
 170         case 31:
 171                 switch (get_xop(inst)) {
 172
 173                 case OP_31_XOP_LWZX:
 174                         rt = get_rt(inst);
 175                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 176                         break;
 177
 178                 case OP_31_XOP_LBZX:
 179                         rt = get_rt(inst);
 180                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 181                         break;
 182
 183                 case OP_31_XOP_LBZUX:
 184                         rt = get_rt(inst);
 185                         ra = get_ra(inst);
 186                         rb = get_rb(inst);
 187
 188                         ea = kvmppc_get_gpr(vcpu, rb);
 189                         if (ra)
 190                                 ea += kvmppc_get_gpr(vcpu, ra);
 191
 192                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 193                         kvmppc_set_gpr(vcpu, ra, ea);
 194                         break;
 195
 196                 case OP_31_XOP_STWX:
 197                         rs = get_rs(inst);
 198                         emulated = kvmppc_handle_store(run, vcpu,
 199                                                        kvmppc_get_gpr(vcpu, rs),
 200                                                        4, 1);
 201                         break;
 202
 203                 case OP_31_XOP_STBX:
 204                         rs = get_rs(inst);
 205                         emulated = kvmppc_handle_store(run, vcpu,
 206                                                        kvmppc_get_gpr(vcpu, rs),
 207                                                        1, 1);
 208                         break;
 209
 210                 case OP_31_XOP_STBUX:
 211                         rs = get_rs(inst);
 212                         ra = get_ra(inst);
 213                         rb = get_rb(inst);
 214
 215                         ea = kvmppc_get_gpr(vcpu, rb);
 216                         if (ra)
 217                                 ea += kvmppc_get_gpr(vcpu, ra);
 218
 219                         emulated = kvmppc_handle_store(run, vcpu,
 220                                                        kvmppc_get_gpr(vcpu, rs),
 221                                                        1, 1);
 222                         kvmppc_set_gpr(vcpu, rs, ea);
 223                         break;
 224
 225                 case OP_31_XOP_LHAX:
 226                         rt = get_rt(inst);
 227                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 228                         break;
 229
 230                 case OP_31_XOP_LHZX:
 231                         rt = get_rt(inst);
 232                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 233                         break;
 234
 235                 case OP_31_XOP_LHZUX:
 236                         rt = get_rt(inst);
 237                         ra = get_ra(inst);
 238                         rb = get_rb(inst);
 239
 240                         ea = kvmppc_get_gpr(vcpu, rb);
 241                         if (ra)
 242                                 ea += kvmppc_get_gpr(vcpu, ra);
 243
 244                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 245                         kvmppc_set_gpr(vcpu, ra, ea);
 246                         break;
 247
 248                 case OP_31_XOP_MFSPR:
 249                         sprn = get_sprn(inst);
 250                         rt = get_rt(inst);
 251
 252                         switch (sprn) {
 253                         case SPRN_SRR0:
 254                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr0);
 255                                 break;
 256                         case SPRN_SRR1:
 257                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->srr1);
 258                                 break;
 259                         case SPRN_PVR:
 260                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
 261                         case SPRN_PIR:
 262                                 kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
 263                         case SPRN_MSSSR0:
 264                                 kvmppc_set_gpr(vcpu, rt, 0); break;
 265
 266                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 267                          * the guest can always access the real TB anyways.
 268                          * In fact, we probably will never see these traps. */
 269                         case SPRN_TBWL:
 270                                 kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
 271                         case SPRN_TBWU:
 272                                 kvmppc_set_gpr(vcpu, rt, get_tb()); break;
 273
 274                         case SPRN_SPRG0:
 275                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg0);
 276                                 break;
 277                         case SPRN_SPRG1:
 278                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg1);
 279                                 break;
 280                         case SPRN_SPRG2:
 281                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg2);
 282                                 break;
 283                         case SPRN_SPRG3:
 284                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->sprg3);
 285                                 break;
 286                         /* Note: SPRG4-7 are user-readable, so we don't get
 287                          * a trap. */
 288
 289                         case SPRN_DEC:
 290                         {
 291                                 kvmppc_set_gpr(vcpu, rt,
 292                                                kvmppc_get_dec(vcpu, get_tb()));
 293                                 break;
 294                         }
 295                         default:
 296                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 297                                 if (emulated == EMULATE_FAIL) {
 298                                         printk("mfspr: unknown spr %x\n", sprn);
 299                                         kvmppc_set_gpr(vcpu, rt, 0);
 300                                 }
 301                                 break;
 302                         }
 303                         kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
 304                         break;
 305
 306                 case OP_31_XOP_STHX:
 307                         rs = get_rs(inst);
 308                         ra = get_ra(inst);
 309                         rb = get_rb(inst);
 310
 311                         emulated = kvmppc_handle_store(run, vcpu,
 312                                                        kvmppc_get_gpr(vcpu, rs),
 313                                                        2, 1);
 314                         break;
 315
 316                 case OP_31_XOP_STHUX:
 317                         rs = get_rs(inst);
 318                         ra = get_ra(inst);
 319                         rb = get_rb(inst);
 320
 321                         ea = kvmppc_get_gpr(vcpu, rb);
 322                         if (ra)
 323                                 ea += kvmppc_get_gpr(vcpu, ra);
 324
 325                         emulated = kvmppc_handle_store(run, vcpu,
 326                                                        kvmppc_get_gpr(vcpu, rs),
 327                                                        2, 1);
 328                         kvmppc_set_gpr(vcpu, ra, ea);
 329                         break;
 330
 331                 case OP_31_XOP_MTSPR:
 332                         sprn = get_sprn(inst);
 333                         rs = get_rs(inst);
 334                         switch (sprn) {
 335                         case SPRN_SRR0:
 336                                 vcpu->arch.shared->srr0 = kvmppc_get_gpr(vcpu, rs);
 337                                 break;
 338                         case SPRN_SRR1:
 339                                 vcpu->arch.shared->srr1 = kvmppc_get_gpr(vcpu, rs);
 340                                 break;
 341
 342                         /* XXX We need to context-switch the timebase for
 343                          * watchdog and FIT. */
 344                         case SPRN_TBWL: break;
 345                         case SPRN_TBWU: break;
 346
 347                         case SPRN_MSSSR0: break;
 348
 349                         case SPRN_DEC:
 350                                 vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
 351                                 kvmppc_emulate_dec(vcpu);
 352                                 break;
 353
 354                         case SPRN_SPRG0:
 355                                 vcpu->arch.shared->sprg0 = kvmppc_get_gpr(vcpu, rs);
 356                                 break;
 357                         case SPRN_SPRG1:
 358                                 vcpu->arch.shared->sprg1 = kvmppc_get_gpr(vcpu, rs);
 359                                 break;
 360                         case SPRN_SPRG2:
 361                                 vcpu->arch.shared->sprg2 = kvmppc_get_gpr(vcpu, rs);
 362                                 break;
 363                         case SPRN_SPRG3:
 364                                 vcpu->arch.shared->sprg3 = kvmppc_get_gpr(vcpu, rs);
 365                                 break;
 366
 367                         default:
 368                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 369                                 if (emulated == EMULATE_FAIL)
 370                                         printk("mtspr: unknown spr %x\n", sprn);
 371                                 break;
 372                         }
 373                         kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
 374                         break;
 375
 376                 case OP_31_XOP_DCBI:
 377                         /* Do nothing. The guest is performing dcbi because
 378                          * hardware DMA is not snooped by the dcache, but
 379                          * emulated DMA either goes through the dcache as
 380                          * normal writes, or the host kernel has handled dcache
 381                          * coherence. */
 382                         break;
 383
 384                 case OP_31_XOP_LWBRX:
 385                         rt = get_rt(inst);
 386                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 387                         break;
 388
 389                 case OP_31_XOP_TLBSYNC:
 390                         break;
 391
 392                 case OP_31_XOP_STWBRX:
 393                         rs = get_rs(inst);
 394                         ra = get_ra(inst);
 395                         rb = get_rb(inst);
 396
 397                         emulated = kvmppc_handle_store(run, vcpu,
 398                                                        kvmppc_get_gpr(vcpu, rs),
 399                                                        4, 0);
 400                         break;
 401
 402                 case OP_31_XOP_LHBRX:
 403                         rt = get_rt(inst);
 404                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 405                         break;
 406
 407                 case OP_31_XOP_STHBRX:
 408                         rs = get_rs(inst);
 409                         ra = get_ra(inst);
 410                         rb = get_rb(inst);
 411
 412                         emulated = kvmppc_handle_store(run, vcpu,
 413                                                        kvmppc_get_gpr(vcpu, rs),
 414                                                        2, 0);
 415                         break;
 416
 417                 default:
 418                         /* Attempt core-specific emulation below. */
 419                         emulated = EMULATE_FAIL;
 420                 }
 421                 break;
 422
 423         case OP_LWZ:
 424                 rt = get_rt(inst);
 425                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 426                 break;
 427
 428         case OP_LWZU:
 429                 ra = get_ra(inst);
 430                 rt = get_rt(inst);
 431                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 432                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 433                 break;
 434
 435         case OP_LBZ:
 436                 rt = get_rt(inst);
 437                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 438                 break;
 439
 440         case OP_LBZU:
 441                 ra = get_ra(inst);
 442                 rt = get_rt(inst);
 443                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 444                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 445                 break;
 446
 447         case OP_STW:
 448                 rs = get_rs(inst);
 449                 emulated = kvmppc_handle_store(run, vcpu,
 450                                                kvmppc_get_gpr(vcpu, rs),
 451                                                4, 1);
 452                 break;
 453
 454         case OP_STWU:
 455                 ra = get_ra(inst);
 456                 rs = get_rs(inst);
 457                 emulated = kvmppc_handle_store(run, vcpu,
 458                                                kvmppc_get_gpr(vcpu, rs),
 459                                                4, 1);
 460                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 461                 break;
 462
 463         case OP_STB:
 464                 rs = get_rs(inst);
 465                 emulated = kvmppc_handle_store(run, vcpu,
 466                                                kvmppc_get_gpr(vcpu, rs),
 467                                                1, 1);
 468                 break;
 469
 470         case OP_STBU:
 471                 ra = get_ra(inst);
 472                 rs = get_rs(inst);
 473                 emulated = kvmppc_handle_store(run, vcpu,
 474                                                kvmppc_get_gpr(vcpu, rs),
 475                                                1, 1);
 476                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 477                 break;
 478
 479         case OP_LHZ:
 480                 rt = get_rt(inst);
 481                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 482                 break;
 483
 484         case OP_LHZU:
 485                 ra = get_ra(inst);
 486                 rt = get_rt(inst);
 487                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 488                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 489                 break;
 490
 491         case OP_LHA:
 492                 rt = get_rt(inst);
 493                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 494                 break;
 495
 496         case OP_LHAU:
 497                 ra = get_ra(inst);
 498                 rt = get_rt(inst);
 499                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 500                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 501                 break;
 502
 503         case OP_STH:
 504                 rs = get_rs(inst);
 505                 emulated = kvmppc_handle_store(run, vcpu,
 506                                                kvmppc_get_gpr(vcpu, rs),
 507                                                2, 1);
 508                 break;
 509
 510         case OP_STHU:
 511                 ra = get_ra(inst);
 512                 rs = get_rs(inst);
 513                 emulated = kvmppc_handle_store(run, vcpu,
 514                                                kvmppc_get_gpr(vcpu, rs),
 515                                                2, 1);
 516                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 517                 break;
 518
 519         default:
 520                 emulated = EMULATE_FAIL;
 521         }
 522
 523         if (emulated == EMULATE_FAIL) {
 524                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 525                 if (emulated == EMULATE_AGAIN) {
 526                         advance = 0;
 527                 } else if (emulated == EMULATE_FAIL) {
 528                         advance = 0;
 529                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 530                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 531                         kvmppc_core_queue_program(vcpu, 0);
 532                 }
 533         }
 534
 535         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 536
 537         /* Advance past emulated instruction. */
 538         if (advance)
 539                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 540
 541         return emulated;
 542 }