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_STBUX     247
  42 #define OP_31_XOP_LHZX      279
  43 #define OP_31_XOP_LHZUX     311
  44 #define OP_31_XOP_MFSPR     339
  45 #define OP_31_XOP_STHX      407
  46 #define OP_31_XOP_STHUX     439
  47 #define OP_31_XOP_MTSPR     467
  48 #define OP_31_XOP_DCBI      470
  49 #define OP_31_XOP_LWBRX     534
  50 #define OP_31_XOP_TLBSYNC   566
  51 #define OP_31_XOP_STWBRX    662
  52 #define OP_31_XOP_LHBRX     790
  53 #define OP_31_XOP_STHBRX    918
  54
  55 #define OP_LWZ  32
  56 #define OP_LWZU 33
  57 #define OP_LBZ  34
  58 #define OP_LBZU 35
  59 #define OP_STW  36
  60 #define OP_STWU 37
  61 #define OP_STB  38
  62 #define OP_STBU 39
  63 #define OP_LHZ  40
  64 #define OP_LHZU 41
  65 #define OP_LHA  42
  66 #define OP_LHAU 43
  67 #define OP_STH  44
  68 #define OP_STHU 45
  69
  70 #ifdef CONFIG_PPC64
  71 static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
  72 {
  73         return 1;
  74 }
  75 #else
  76 static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
  77 {
  78         return vcpu->arch.tcr & TCR_DIE;
  79 }
  80 #endif
  81
  82 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  83 {
  84         unsigned long dec_nsec;
  85
  86         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  87 #ifdef CONFIG_PPC64
  88         /* mtdec lowers the interrupt line when positive. */
  89         kvmppc_core_dequeue_dec(vcpu);
  90
  91         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  92         if (vcpu->arch.dec & 0x80000000) {
  93                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  94                 kvmppc_core_queue_dec(vcpu);
  95                 return;
  96         }
  97 #endif
  98         if (kvmppc_dec_enabled(vcpu)) {
  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                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 104                 dec_nsec = vcpu->arch.dec;
 105                 dec_nsec *= 1000;
 106                 dec_nsec /= tb_ticks_per_usec;
 107                 hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
 108                               HRTIMER_MODE_REL);
 109                 vcpu->arch.dec_jiffies = get_tb();
 110         } else {
 111                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 112         }
 113 }
 114
 115 /* XXX to do:
 116  * lhax
 117  * lhaux
 118  * lswx
 119  * lswi
 120  * stswx
 121  * stswi
 122  * lha
 123  * lhau
 124  * lmw
 125  * stmw
 126  *
 127  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 128  */
 129 /* XXX Should probably auto-generate instruction decoding for a particular core
 130  * from opcode tables in the future. */
 131 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 132 {
 133         u32 inst = vcpu->arch.last_inst;
 134         u32 ea;
 135         int ra;
 136         int rb;
 137         int rs;
 138         int rt;
 139         int sprn;
 140         enum emulation_result emulated = EMULATE_DONE;
 141         int advance = 1;
 142
 143         /* this default type might be overwritten by subcategories */
 144         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 145
 146         pr_debug(KERN_INFO "Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 147
 148         /* Try again next time */
 149         if (inst == KVM_INST_FETCH_FAILED)
 150                 return EMULATE_DONE;
 151
 152         switch (get_op(inst)) {
 153         case OP_TRAP:
 154 #ifdef CONFIG_PPC64
 155         case OP_TRAP_64:
 156                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 157 #else
 158                 kvmppc_core_queue_program(vcpu, vcpu->arch.esr | ESR_PTR);
 159 #endif
 160                 advance = 0;
 161                 break;
 162
 163         case 31:
 164                 switch (get_xop(inst)) {
 165
 166                 case OP_31_XOP_LWZX:
 167                         rt = get_rt(inst);
 168                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 169                         break;
 170
 171                 case OP_31_XOP_LBZX:
 172                         rt = get_rt(inst);
 173                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 174                         break;
 175
 176                 case OP_31_XOP_STWX:
 177                         rs = get_rs(inst);
 178                         emulated = kvmppc_handle_store(run, vcpu,
 179                                                        kvmppc_get_gpr(vcpu, rs),
 180                                                        4, 1);
 181                         break;
 182
 183                 case OP_31_XOP_STBX:
 184                         rs = get_rs(inst);
 185                         emulated = kvmppc_handle_store(run, vcpu,
 186                                                        kvmppc_get_gpr(vcpu, rs),
 187                                                        1, 1);
 188                         break;
 189
 190                 case OP_31_XOP_STBUX:
 191                         rs = get_rs(inst);
 192                         ra = get_ra(inst);
 193                         rb = get_rb(inst);
 194
 195                         ea = kvmppc_get_gpr(vcpu, rb);
 196                         if (ra)
 197                                 ea += kvmppc_get_gpr(vcpu, ra);
 198
 199                         emulated = kvmppc_handle_store(run, vcpu,
 200                                                        kvmppc_get_gpr(vcpu, rs),
 201                                                        1, 1);
 202                         kvmppc_set_gpr(vcpu, rs, ea);
 203                         break;
 204
 205                 case OP_31_XOP_LHZX:
 206                         rt = get_rt(inst);
 207                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 208                         break;
 209
 210                 case OP_31_XOP_LHZUX:
 211                         rt = get_rt(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_load(run, vcpu, rt, 2, 1);
 220                         kvmppc_set_gpr(vcpu, ra, ea);
 221                         break;
 222
 223                 case OP_31_XOP_MFSPR:
 224                         sprn = get_sprn(inst);
 225                         rt = get_rt(inst);
 226
 227                         switch (sprn) {
 228                         case SPRN_SRR0:
 229                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.srr0); break;
 230                         case SPRN_SRR1:
 231                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.srr1); break;
 232                         case SPRN_PVR:
 233                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
 234                         case SPRN_PIR:
 235                                 kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
 236                         case SPRN_MSSSR0:
 237                                 kvmppc_set_gpr(vcpu, rt, 0); break;
 238
 239                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 240                          * the guest can always access the real TB anyways.
 241                          * In fact, we probably will never see these traps. */
 242                         case SPRN_TBWL:
 243                                 kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
 244                         case SPRN_TBWU:
 245                                 kvmppc_set_gpr(vcpu, rt, get_tb()); break;
 246
 247                         case SPRN_SPRG0:
 248                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg0); break;
 249                         case SPRN_SPRG1:
 250                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg1); break;
 251                         case SPRN_SPRG2:
 252                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg2); break;
 253                         case SPRN_SPRG3:
 254                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg3); break;
 255                         /* Note: SPRG4-7 are user-readable, so we don't get
 256                          * a trap. */
 257
 258                         case SPRN_DEC:
 259                         {
 260                                 u64 jd = get_tb() - vcpu->arch.dec_jiffies;
 261                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.dec - jd);
 262                                 pr_debug(KERN_INFO "mfDEC: %x - %llx = %lx\n",
 263                                          vcpu->arch.dec, jd,
 264                                          kvmppc_get_gpr(vcpu, rt));
 265                                 break;
 266                         }
 267                         default:
 268                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 269                                 if (emulated == EMULATE_FAIL) {
 270                                         printk("mfspr: unknown spr %x\n", sprn);
 271                                         kvmppc_set_gpr(vcpu, rt, 0);
 272                                 }
 273                                 break;
 274                         }
 275                         break;
 276
 277                 case OP_31_XOP_STHX:
 278                         rs = get_rs(inst);
 279                         ra = get_ra(inst);
 280                         rb = get_rb(inst);
 281
 282                         emulated = kvmppc_handle_store(run, vcpu,
 283                                                        kvmppc_get_gpr(vcpu, rs),
 284                                                        2, 1);
 285                         break;
 286
 287                 case OP_31_XOP_STHUX:
 288                         rs = get_rs(inst);
 289                         ra = get_ra(inst);
 290                         rb = get_rb(inst);
 291
 292                         ea = kvmppc_get_gpr(vcpu, rb);
 293                         if (ra)
 294                                 ea += kvmppc_get_gpr(vcpu, ra);
 295
 296                         emulated = kvmppc_handle_store(run, vcpu,
 297                                                        kvmppc_get_gpr(vcpu, rs),
 298                                                        2, 1);
 299                         kvmppc_set_gpr(vcpu, ra, ea);
 300                         break;
 301
 302                 case OP_31_XOP_MTSPR:
 303                         sprn = get_sprn(inst);
 304                         rs = get_rs(inst);
 305                         switch (sprn) {
 306                         case SPRN_SRR0:
 307                                 vcpu->arch.srr0 = kvmppc_get_gpr(vcpu, rs); break;
 308                         case SPRN_SRR1:
 309                                 vcpu->arch.srr1 = kvmppc_get_gpr(vcpu, rs); break;
 310
 311                         /* XXX We need to context-switch the timebase for
 312                          * watchdog and FIT. */
 313                         case SPRN_TBWL: break;
 314                         case SPRN_TBWU: break;
 315
 316                         case SPRN_MSSSR0: break;
 317
 318                         case SPRN_DEC:
 319                                 vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
 320                                 kvmppc_emulate_dec(vcpu);
 321                                 break;
 322
 323                         case SPRN_SPRG0:
 324                                 vcpu->arch.sprg0 = kvmppc_get_gpr(vcpu, rs); break;
 325                         case SPRN_SPRG1:
 326                                 vcpu->arch.sprg1 = kvmppc_get_gpr(vcpu, rs); break;
 327                         case SPRN_SPRG2:
 328                                 vcpu->arch.sprg2 = kvmppc_get_gpr(vcpu, rs); break;
 329                         case SPRN_SPRG3:
 330                                 vcpu->arch.sprg3 = kvmppc_get_gpr(vcpu, rs); break;
 331
 332                         default:
 333                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 334                                 if (emulated == EMULATE_FAIL)
 335                                         printk("mtspr: unknown spr %x\n", sprn);
 336                                 break;
 337                         }
 338                         break;
 339
 340                 case OP_31_XOP_DCBI:
 341                         /* Do nothing. The guest is performing dcbi because
 342                          * hardware DMA is not snooped by the dcache, but
 343                          * emulated DMA either goes through the dcache as
 344                          * normal writes, or the host kernel has handled dcache
 345                          * coherence. */
 346                         break;
 347
 348                 case OP_31_XOP_LWBRX:
 349                         rt = get_rt(inst);
 350                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 351                         break;
 352
 353                 case OP_31_XOP_TLBSYNC:
 354                         break;
 355
 356                 case OP_31_XOP_STWBRX:
 357                         rs = get_rs(inst);
 358                         ra = get_ra(inst);
 359                         rb = get_rb(inst);
 360
 361                         emulated = kvmppc_handle_store(run, vcpu,
 362                                                        kvmppc_get_gpr(vcpu, rs),
 363                                                        4, 0);
 364                         break;
 365
 366                 case OP_31_XOP_LHBRX:
 367                         rt = get_rt(inst);
 368                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 369                         break;
 370
 371                 case OP_31_XOP_STHBRX:
 372                         rs = get_rs(inst);
 373                         ra = get_ra(inst);
 374                         rb = get_rb(inst);
 375
 376                         emulated = kvmppc_handle_store(run, vcpu,
 377                                                        kvmppc_get_gpr(vcpu, rs),
 378                                                        2, 0);
 379                         break;
 380
 381                 default:
 382                         /* Attempt core-specific emulation below. */
 383                         emulated = EMULATE_FAIL;
 384                 }
 385                 break;
 386
 387         case OP_LWZ:
 388                 rt = get_rt(inst);
 389                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 390                 break;
 391
 392         case OP_LWZU:
 393                 ra = get_ra(inst);
 394                 rt = get_rt(inst);
 395                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 396                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 397                 break;
 398
 399         case OP_LBZ:
 400                 rt = get_rt(inst);
 401                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 402                 break;
 403
 404         case OP_LBZU:
 405                 ra = get_ra(inst);
 406                 rt = get_rt(inst);
 407                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 408                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 409                 break;
 410
 411         case OP_STW:
 412                 rs = get_rs(inst);
 413                 emulated = kvmppc_handle_store(run, vcpu,
 414                                                kvmppc_get_gpr(vcpu, rs),
 415                                                4, 1);
 416                 break;
 417
 418         case OP_STWU:
 419                 ra = get_ra(inst);
 420                 rs = get_rs(inst);
 421                 emulated = kvmppc_handle_store(run, vcpu,
 422                                                kvmppc_get_gpr(vcpu, rs),
 423                                                4, 1);
 424                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 425                 break;
 426
 427         case OP_STB:
 428                 rs = get_rs(inst);
 429                 emulated = kvmppc_handle_store(run, vcpu,
 430                                                kvmppc_get_gpr(vcpu, rs),
 431                                                1, 1);
 432                 break;
 433
 434         case OP_STBU:
 435                 ra = get_ra(inst);
 436                 rs = get_rs(inst);
 437                 emulated = kvmppc_handle_store(run, vcpu,
 438                                                kvmppc_get_gpr(vcpu, rs),
 439                                                1, 1);
 440                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 441                 break;
 442
 443         case OP_LHZ:
 444                 rt = get_rt(inst);
 445                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 446                 break;
 447
 448         case OP_LHZU:
 449                 ra = get_ra(inst);
 450                 rt = get_rt(inst);
 451                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 452                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 453                 break;
 454
 455         case OP_LHA:
 456                 rt = get_rt(inst);
 457                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 458                 break;
 459
 460         case OP_LHAU:
 461                 ra = get_ra(inst);
 462                 rt = get_rt(inst);
 463                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 464                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 465                 break;
 466
 467         case OP_STH:
 468                 rs = get_rs(inst);
 469                 emulated = kvmppc_handle_store(run, vcpu,
 470                                                kvmppc_get_gpr(vcpu, rs),
 471                                                2, 1);
 472                 break;
 473
 474         case OP_STHU:
 475                 ra = get_ra(inst);
 476                 rs = get_rs(inst);
 477                 emulated = kvmppc_handle_store(run, vcpu,
 478                                                kvmppc_get_gpr(vcpu, rs),
 479                                                2, 1);
 480                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 481                 break;
 482
 483         default:
 484                 emulated = EMULATE_FAIL;
 485         }
 486
 487         if (emulated == EMULATE_FAIL) {
 488                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 489                 if (emulated == EMULATE_FAIL) {
 490                         advance = 0;
 491                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 492                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 493                         kvmppc_core_queue_program(vcpu, 0);
 494                 }
 495         }
 496
 497         trace_kvm_ppc_instr(inst, vcpu->arch.pc, emulated);
 498
 499         if (advance)
 500                 vcpu->arch.pc += 4; /* Advance past emulated instruction. */
 501
 502         return emulated;
 503 }