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_STH  44
  66 #define OP_STHU 45
  67
  68 #ifdef CONFIG_PPC64
  69 static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
  70 {
  71         return 1;
  72 }
  73 #else
  74 static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
  75 {
  76         return vcpu->arch.tcr & TCR_DIE;
  77 }
  78 #endif
  79
  80 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  81 {
  82         unsigned long dec_nsec;
  83
  84         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  85 #ifdef CONFIG_PPC64
  86         /* mtdec lowers the interrupt line when positive. */
  87         kvmppc_core_dequeue_dec(vcpu);
  88
  89         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  90         if (vcpu->arch.dec & 0x80000000) {
  91                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  92                 kvmppc_core_queue_dec(vcpu);
  93                 return;
  94         }
  95 #endif
  96         if (kvmppc_dec_enabled(vcpu)) {
  97                 /* The decrementer ticks at the same rate as the timebase, so
  98                  * that's how we convert the guest DEC value to the number of
  99                  * host ticks. */
 100
 101                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 102                 dec_nsec = vcpu->arch.dec;
 103                 dec_nsec *= 1000;
 104                 dec_nsec /= tb_ticks_per_usec;
 105                 hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
 106                               HRTIMER_MODE_REL);
 107                 vcpu->arch.dec_jiffies = get_tb();
 108         } else {
 109                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
 110         }
 111 }
 112
 113 /* XXX to do:
 114  * lhax
 115  * lhaux
 116  * lswx
 117  * lswi
 118  * stswx
 119  * stswi
 120  * lha
 121  * lhau
 122  * lmw
 123  * stmw
 124  *
 125  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 126  */
 127 /* XXX Should probably auto-generate instruction decoding for a particular core
 128  * from opcode tables in the future. */
 129 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 130 {
 131         u32 inst = vcpu->arch.last_inst;
 132         u32 ea;
 133         int ra;
 134         int rb;
 135         int rs;
 136         int rt;
 137         int sprn;
 138         enum emulation_result emulated = EMULATE_DONE;
 139         int advance = 1;
 140
 141         /* this default type might be overwritten by subcategories */
 142         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 143
 144         pr_debug(KERN_INFO "Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 145
 146         /* Try again next time */
 147         if (inst == KVM_INST_FETCH_FAILED)
 148                 return EMULATE_DONE;
 149
 150         switch (get_op(inst)) {
 151         case OP_TRAP:
 152 #ifdef CONFIG_PPC64
 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_STWX:
 175                         rs = get_rs(inst);
 176                         emulated = kvmppc_handle_store(run, vcpu,
 177                                                        kvmppc_get_gpr(vcpu, rs),
 178                                                        4, 1);
 179                         break;
 180
 181                 case OP_31_XOP_STBX:
 182                         rs = get_rs(inst);
 183                         emulated = kvmppc_handle_store(run, vcpu,
 184                                                        kvmppc_get_gpr(vcpu, rs),
 185                                                        1, 1);
 186                         break;
 187
 188                 case OP_31_XOP_STBUX:
 189                         rs = get_rs(inst);
 190                         ra = get_ra(inst);
 191                         rb = get_rb(inst);
 192
 193                         ea = kvmppc_get_gpr(vcpu, rb);
 194                         if (ra)
 195                                 ea += kvmppc_get_gpr(vcpu, ra);
 196
 197                         emulated = kvmppc_handle_store(run, vcpu,
 198                                                        kvmppc_get_gpr(vcpu, rs),
 199                                                        1, 1);
 200                         kvmppc_set_gpr(vcpu, rs, ea);
 201                         break;
 202
 203                 case OP_31_XOP_LHZX:
 204                         rt = get_rt(inst);
 205                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 206                         break;
 207
 208                 case OP_31_XOP_LHZUX:
 209                         rt = get_rt(inst);
 210                         ra = get_ra(inst);
 211                         rb = get_rb(inst);
 212
 213                         ea = kvmppc_get_gpr(vcpu, rb);
 214                         if (ra)
 215                                 ea += kvmppc_get_gpr(vcpu, ra);
 216
 217                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 218                         kvmppc_set_gpr(vcpu, ra, ea);
 219                         break;
 220
 221                 case OP_31_XOP_MFSPR:
 222                         sprn = get_sprn(inst);
 223                         rt = get_rt(inst);
 224
 225                         switch (sprn) {
 226                         case SPRN_SRR0:
 227                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.srr0); break;
 228                         case SPRN_SRR1:
 229                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.srr1); break;
 230                         case SPRN_PVR:
 231                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.pvr); break;
 232                         case SPRN_PIR:
 233                                 kvmppc_set_gpr(vcpu, rt, vcpu->vcpu_id); break;
 234                         case SPRN_MSSSR0:
 235                                 kvmppc_set_gpr(vcpu, rt, 0); break;
 236
 237                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 238                          * the guest can always access the real TB anyways.
 239                          * In fact, we probably will never see these traps. */
 240                         case SPRN_TBWL:
 241                                 kvmppc_set_gpr(vcpu, rt, get_tb() >> 32); break;
 242                         case SPRN_TBWU:
 243                                 kvmppc_set_gpr(vcpu, rt, get_tb()); break;
 244
 245                         case SPRN_SPRG0:
 246                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg0); break;
 247                         case SPRN_SPRG1:
 248                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg1); break;
 249                         case SPRN_SPRG2:
 250                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg2); break;
 251                         case SPRN_SPRG3:
 252                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.sprg3); break;
 253                         /* Note: SPRG4-7 are user-readable, so we don't get
 254                          * a trap. */
 255
 256                         case SPRN_DEC:
 257                         {
 258                                 u64 jd = get_tb() - vcpu->arch.dec_jiffies;
 259                                 kvmppc_set_gpr(vcpu, rt, vcpu->arch.dec - jd);
 260                                 pr_debug(KERN_INFO "mfDEC: %x - %llx = %lx\n",
 261                                          vcpu->arch.dec, jd,
 262                                          kvmppc_get_gpr(vcpu, rt));
 263                                 break;
 264                         }
 265                         default:
 266                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 267                                 if (emulated == EMULATE_FAIL) {
 268                                         printk("mfspr: unknown spr %x\n", sprn);
 269                                         kvmppc_set_gpr(vcpu, rt, 0);
 270                                 }
 271                                 break;
 272                         }
 273                         break;
 274
 275                 case OP_31_XOP_STHX:
 276                         rs = get_rs(inst);
 277                         ra = get_ra(inst);
 278                         rb = get_rb(inst);
 279
 280                         emulated = kvmppc_handle_store(run, vcpu,
 281                                                        kvmppc_get_gpr(vcpu, rs),
 282                                                        2, 1);
 283                         break;
 284
 285                 case OP_31_XOP_STHUX:
 286                         rs = get_rs(inst);
 287                         ra = get_ra(inst);
 288                         rb = get_rb(inst);
 289
 290                         ea = kvmppc_get_gpr(vcpu, rb);
 291                         if (ra)
 292                                 ea += kvmppc_get_gpr(vcpu, ra);
 293
 294                         emulated = kvmppc_handle_store(run, vcpu,
 295                                                        kvmppc_get_gpr(vcpu, rs),
 296                                                        2, 1);
 297                         kvmppc_set_gpr(vcpu, ra, ea);
 298                         break;
 299
 300                 case OP_31_XOP_MTSPR:
 301                         sprn = get_sprn(inst);
 302                         rs = get_rs(inst);
 303                         switch (sprn) {
 304                         case SPRN_SRR0:
 305                                 vcpu->arch.srr0 = kvmppc_get_gpr(vcpu, rs); break;
 306                         case SPRN_SRR1:
 307                                 vcpu->arch.srr1 = kvmppc_get_gpr(vcpu, rs); break;
 308
 309                         /* XXX We need to context-switch the timebase for
 310                          * watchdog and FIT. */
 311                         case SPRN_TBWL: break;
 312                         case SPRN_TBWU: break;
 313
 314                         case SPRN_MSSSR0: break;
 315
 316                         case SPRN_DEC:
 317                                 vcpu->arch.dec = kvmppc_get_gpr(vcpu, rs);
 318                                 kvmppc_emulate_dec(vcpu);
 319                                 break;
 320
 321                         case SPRN_SPRG0:
 322                                 vcpu->arch.sprg0 = kvmppc_get_gpr(vcpu, rs); break;
 323                         case SPRN_SPRG1:
 324                                 vcpu->arch.sprg1 = kvmppc_get_gpr(vcpu, rs); break;
 325                         case SPRN_SPRG2:
 326                                 vcpu->arch.sprg2 = kvmppc_get_gpr(vcpu, rs); break;
 327                         case SPRN_SPRG3:
 328                                 vcpu->arch.sprg3 = kvmppc_get_gpr(vcpu, rs); break;
 329
 330                         default:
 331                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 332                                 if (emulated == EMULATE_FAIL)
 333                                         printk("mtspr: unknown spr %x\n", sprn);
 334                                 break;
 335                         }
 336                         break;
 337
 338                 case OP_31_XOP_DCBI:
 339                         /* Do nothing. The guest is performing dcbi because
 340                          * hardware DMA is not snooped by the dcache, but
 341                          * emulated DMA either goes through the dcache as
 342                          * normal writes, or the host kernel has handled dcache
 343                          * coherence. */
 344                         break;
 345
 346                 case OP_31_XOP_LWBRX:
 347                         rt = get_rt(inst);
 348                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 349                         break;
 350
 351                 case OP_31_XOP_TLBSYNC:
 352                         break;
 353
 354                 case OP_31_XOP_STWBRX:
 355                         rs = get_rs(inst);
 356                         ra = get_ra(inst);
 357                         rb = get_rb(inst);
 358
 359                         emulated = kvmppc_handle_store(run, vcpu,
 360                                                        kvmppc_get_gpr(vcpu, rs),
 361                                                        4, 0);
 362                         break;
 363
 364                 case OP_31_XOP_LHBRX:
 365                         rt = get_rt(inst);
 366                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 367                         break;
 368
 369                 case OP_31_XOP_STHBRX:
 370                         rs = get_rs(inst);
 371                         ra = get_ra(inst);
 372                         rb = get_rb(inst);
 373
 374                         emulated = kvmppc_handle_store(run, vcpu,
 375                                                        kvmppc_get_gpr(vcpu, rs),
 376                                                        2, 0);
 377                         break;
 378
 379                 default:
 380                         /* Attempt core-specific emulation below. */
 381                         emulated = EMULATE_FAIL;
 382                 }
 383                 break;
 384
 385         case OP_LWZ:
 386                 rt = get_rt(inst);
 387                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 388                 break;
 389
 390         case OP_LWZU:
 391                 ra = get_ra(inst);
 392                 rt = get_rt(inst);
 393                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 394                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 395                 break;
 396
 397         case OP_LBZ:
 398                 rt = get_rt(inst);
 399                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 400                 break;
 401
 402         case OP_LBZU:
 403                 ra = get_ra(inst);
 404                 rt = get_rt(inst);
 405                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 406                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 407                 break;
 408
 409         case OP_STW:
 410                 rs = get_rs(inst);
 411                 emulated = kvmppc_handle_store(run, vcpu,
 412                                                kvmppc_get_gpr(vcpu, rs),
 413                                                4, 1);
 414                 break;
 415
 416         case OP_STWU:
 417                 ra = get_ra(inst);
 418                 rs = get_rs(inst);
 419                 emulated = kvmppc_handle_store(run, vcpu,
 420                                                kvmppc_get_gpr(vcpu, rs),
 421                                                4, 1);
 422                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 423                 break;
 424
 425         case OP_STB:
 426                 rs = get_rs(inst);
 427                 emulated = kvmppc_handle_store(run, vcpu,
 428                                                kvmppc_get_gpr(vcpu, rs),
 429                                                1, 1);
 430                 break;
 431
 432         case OP_STBU:
 433                 ra = get_ra(inst);
 434                 rs = get_rs(inst);
 435                 emulated = kvmppc_handle_store(run, vcpu,
 436                                                kvmppc_get_gpr(vcpu, rs),
 437                                                1, 1);
 438                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 439                 break;
 440
 441         case OP_LHZ:
 442                 rt = get_rt(inst);
 443                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 444                 break;
 445
 446         case OP_LHZU:
 447                 ra = get_ra(inst);
 448                 rt = get_rt(inst);
 449                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 450                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 451                 break;
 452
 453         case OP_STH:
 454                 rs = get_rs(inst);
 455                 emulated = kvmppc_handle_store(run, vcpu,
 456                                                kvmppc_get_gpr(vcpu, rs),
 457                                                2, 1);
 458                 break;
 459
 460         case OP_STHU:
 461                 ra = get_ra(inst);
 462                 rs = get_rs(inst);
 463                 emulated = kvmppc_handle_store(run, vcpu,
 464                                                kvmppc_get_gpr(vcpu, rs),
 465                                                2, 1);
 466                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed);
 467                 break;
 468
 469         default:
 470                 emulated = EMULATE_FAIL;
 471         }
 472
 473         if (emulated == EMULATE_FAIL) {
 474                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 475                 if (emulated == EMULATE_FAIL) {
 476                         advance = 0;
 477                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 478                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 479                         kvmppc_core_queue_program(vcpu, 0);
 480                 }
 481         }
 482
 483         trace_kvm_ppc_instr(inst, vcpu->arch.pc, emulated);
 484
 485         if (advance)
 486                 vcpu->arch.pc += 4; /* Advance past emulated instruction. */
 487
 488         return emulated;
 489 }