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 #include <linux/clockchips.h>
  27
  28 #include <asm/reg.h>
  29 #include <asm/time.h>
  30 #include <asm/byteorder.h>
  31 #include <asm/kvm_ppc.h>
  32 #include <asm/disassemble.h>
  33 #include "timing.h"
  34 #include "trace.h"
  35
  36 #define OP_TRAP 3
  37 #define OP_TRAP_64 2
  38
  39 #define OP_31_XOP_TRAP      4
  40 #define OP_31_XOP_LWZX      23
  41 #define OP_31_XOP_TRAP_64   68
  42 #define OP_31_XOP_DCBF      86
  43 #define OP_31_XOP_LBZX      87
  44 #define OP_31_XOP_STWX      151
  45 #define OP_31_XOP_STBX      215
  46 #define OP_31_XOP_LBZUX     119
  47 #define OP_31_XOP_STBUX     247
  48 #define OP_31_XOP_LHZX      279
  49 #define OP_31_XOP_LHZUX     311
  50 #define OP_31_XOP_MFSPR     339
  51 #define OP_31_XOP_LHAX      343
  52 #define OP_31_XOP_STHX      407
  53 #define OP_31_XOP_STHUX     439
  54 #define OP_31_XOP_MTSPR     467
  55 #define OP_31_XOP_DCBI      470
  56 #define OP_31_XOP_LWBRX     534
  57 #define OP_31_XOP_TLBSYNC   566
  58 #define OP_31_XOP_STWBRX    662
  59 #define OP_31_XOP_LHBRX     790
  60 #define OP_31_XOP_STHBRX    918
  61
  62 #define OP_LWZ  32
  63 #define OP_LD   58
  64 #define OP_LWZU 33
  65 #define OP_LBZ  34
  66 #define OP_LBZU 35
  67 #define OP_STW  36
  68 #define OP_STWU 37
  69 #define OP_STD  62
  70 #define OP_STB  38
  71 #define OP_STBU 39
  72 #define OP_LHZ  40
  73 #define OP_LHZU 41
  74 #define OP_LHA  42
  75 #define OP_LHAU 43
  76 #define OP_STH  44
  77 #define OP_STHU 45
  78
  79 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  80 {
  81         unsigned long dec_nsec;
  82         unsigned long long dec_time;
  83
  84         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  85         hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  86
  87 #ifdef CONFIG_PPC_BOOK3S
  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                 kvmppc_core_queue_dec(vcpu);
  94                 return;
  95         }
  96 #endif
  97
  98 #ifdef CONFIG_BOOKE
  99         /* On BOOKE, DEC = 0 is as good as decrementer not enabled */
 100         if (vcpu->arch.dec == 0)
 101                 return;
 102 #endif
 103
 104         /*
 105          * The decrementer ticks at the same rate as the timebase, so
 106          * that's how we convert the guest DEC value to the number of
 107          * host ticks.
 108          */
 109
 110         dec_time = vcpu->arch.dec;
 111         /*
 112          * Guest timebase ticks at the same frequency as host decrementer.
 113          * So use the host decrementer calculations for decrementer emulation.
 114          */
 115         dec_time = dec_time << decrementer_clockevent.shift;
 116         do_div(dec_time, decrementer_clockevent.mult);
 117         dec_nsec = do_div(dec_time, NSEC_PER_SEC);
 118         hrtimer_start(&vcpu->arch.dec_timer,
 119                 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
 120         vcpu->arch.dec_jiffies = get_tb();
 121 }
 122
 123 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 124 {
 125         u64 jd = tb - vcpu->arch.dec_jiffies;
 126
 127 #ifdef CONFIG_BOOKE
 128         if (vcpu->arch.dec < jd)
 129                 return 0;
 130 #endif
 131
 132         return vcpu->arch.dec - jd;
 133 }
 134
 135 static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
 136 {
 137         enum emulation_result emulated = EMULATE_DONE;
 138         ulong spr_val = kvmppc_get_gpr(vcpu, rs);
 139
 140         switch (sprn) {
 141         case SPRN_SRR0:
 142                 vcpu->arch.shared->srr0 = spr_val;
 143                 break;
 144         case SPRN_SRR1:
 145                 vcpu->arch.shared->srr1 = spr_val;
 146                 break;
 147
 148         /* XXX We need to context-switch the timebase for
 149          * watchdog and FIT. */
 150         case SPRN_TBWL: break;
 151         case SPRN_TBWU: break;
 152
 153         case SPRN_DEC:
 154                 vcpu->arch.dec = spr_val;
 155                 kvmppc_emulate_dec(vcpu);
 156                 break;
 157
 158         case SPRN_SPRG0:
 159                 vcpu->arch.shared->sprg0 = spr_val;
 160                 break;
 161         case SPRN_SPRG1:
 162                 vcpu->arch.shared->sprg1 = spr_val;
 163                 break;
 164         case SPRN_SPRG2:
 165                 vcpu->arch.shared->sprg2 = spr_val;
 166                 break;
 167         case SPRN_SPRG3:
 168                 vcpu->arch.shared->sprg3 = spr_val;
 169                 break;
 170
 171         default:
 172                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn,
 173                                                      spr_val);
 174                 if (emulated == EMULATE_FAIL)
 175                         printk(KERN_INFO "mtspr: unknown spr "
 176                                 "0x%x\n", sprn);
 177                 break;
 178         }
 179
 180         kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
 181
 182         return emulated;
 183 }
 184
 185 static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
 186 {
 187         enum emulation_result emulated = EMULATE_DONE;
 188         ulong spr_val = 0;
 189
 190         switch (sprn) {
 191         case SPRN_SRR0:
 192                 spr_val = vcpu->arch.shared->srr0;
 193                 break;
 194         case SPRN_SRR1:
 195                 spr_val = vcpu->arch.shared->srr1;
 196                 break;
 197         case SPRN_PVR:
 198                 spr_val = vcpu->arch.pvr;
 199                 break;
 200         case SPRN_PIR:
 201                 spr_val = vcpu->vcpu_id;
 202                 break;
 203
 204         /* Note: mftb and TBRL/TBWL are user-accessible, so
 205          * the guest can always access the real TB anyways.
 206          * In fact, we probably will never see these traps. */
 207         case SPRN_TBWL:
 208                 spr_val = get_tb() >> 32;
 209                 break;
 210         case SPRN_TBWU:
 211                 spr_val = get_tb();
 212                 break;
 213
 214         case SPRN_SPRG0:
 215                 spr_val = vcpu->arch.shared->sprg0;
 216                 break;
 217         case SPRN_SPRG1:
 218                 spr_val = vcpu->arch.shared->sprg1;
 219                 break;
 220         case SPRN_SPRG2:
 221                 spr_val = vcpu->arch.shared->sprg2;
 222                 break;
 223         case SPRN_SPRG3:
 224                 spr_val = vcpu->arch.shared->sprg3;
 225                 break;
 226         /* Note: SPRG4-7 are user-readable, so we don't get
 227          * a trap. */
 228
 229         case SPRN_DEC:
 230                 spr_val = kvmppc_get_dec(vcpu, get_tb());
 231                 break;
 232         default:
 233                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn,
 234                                                      &spr_val);
 235                 if (unlikely(emulated == EMULATE_FAIL)) {
 236                         printk(KERN_INFO "mfspr: unknown spr "
 237                                 "0x%x\n", sprn);
 238                 }
 239                 break;
 240         }
 241
 242         if (emulated == EMULATE_DONE)
 243                 kvmppc_set_gpr(vcpu, rt, spr_val);
 244         kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
 245
 246         return emulated;
 247 }
 248
 249 /* XXX to do:
 250  * lhax
 251  * lhaux
 252  * lswx
 253  * lswi
 254  * stswx
 255  * stswi
 256  * lha
 257  * lhau
 258  * lmw
 259  * stmw
 260  *
 261  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 262  */
 263 /* XXX Should probably auto-generate instruction decoding for a particular core
 264  * from opcode tables in the future. */
 265 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 266 {
 267         u32 inst = kvmppc_get_last_inst(vcpu);
 268         int ra = get_ra(inst);
 269         int rs = get_rs(inst);
 270         int rt = get_rt(inst);
 271         int sprn = get_sprn(inst);
 272         enum emulation_result emulated = EMULATE_DONE;
 273         int advance = 1;
 274
 275         /* this default type might be overwritten by subcategories */
 276         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 277
 278         pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 279
 280         switch (get_op(inst)) {
 281         case OP_TRAP:
 282 #ifdef CONFIG_PPC_BOOK3S
 283         case OP_TRAP_64:
 284                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 285 #else
 286                 kvmppc_core_queue_program(vcpu,
 287                                           vcpu->arch.shared->esr | ESR_PTR);
 288 #endif
 289                 advance = 0;
 290                 break;
 291
 292         case 31:
 293                 switch (get_xop(inst)) {
 294
 295                 case OP_31_XOP_TRAP:
 296 #ifdef CONFIG_64BIT
 297                 case OP_31_XOP_TRAP_64:
 298 #endif
 299 #ifdef CONFIG_PPC_BOOK3S
 300                         kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 301 #else
 302                         kvmppc_core_queue_program(vcpu,
 303                                         vcpu->arch.shared->esr | ESR_PTR);
 304 #endif
 305                         advance = 0;
 306                         break;
 307                 case OP_31_XOP_LWZX:
 308                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 309                         break;
 310
 311                 case OP_31_XOP_LBZX:
 312                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 313                         break;
 314
 315                 case OP_31_XOP_LBZUX:
 316                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 317                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 318                         break;
 319
 320                 case OP_31_XOP_STWX:
 321                         emulated = kvmppc_handle_store(run, vcpu,
 322                                                        kvmppc_get_gpr(vcpu, rs),
 323                                                        4, 1);
 324                         break;
 325
 326                 case OP_31_XOP_STBX:
 327                         emulated = kvmppc_handle_store(run, vcpu,
 328                                                        kvmppc_get_gpr(vcpu, rs),
 329                                                        1, 1);
 330                         break;
 331
 332                 case OP_31_XOP_STBUX:
 333                         emulated = kvmppc_handle_store(run, vcpu,
 334                                                        kvmppc_get_gpr(vcpu, rs),
 335                                                        1, 1);
 336                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 337                         break;
 338
 339                 case OP_31_XOP_LHAX:
 340                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 341                         break;
 342
 343                 case OP_31_XOP_LHZX:
 344                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 345                         break;
 346
 347                 case OP_31_XOP_LHZUX:
 348                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 349                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 350                         break;
 351
 352                 case OP_31_XOP_MFSPR:
 353                         emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
 354                         break;
 355
 356                 case OP_31_XOP_STHX:
 357                         emulated = kvmppc_handle_store(run, vcpu,
 358                                                        kvmppc_get_gpr(vcpu, rs),
 359                                                        2, 1);
 360                         break;
 361
 362                 case OP_31_XOP_STHUX:
 363                         emulated = kvmppc_handle_store(run, vcpu,
 364                                                        kvmppc_get_gpr(vcpu, rs),
 365                                                        2, 1);
 366                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 367                         break;
 368
 369                 case OP_31_XOP_MTSPR:
 370                         emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
 371                         break;
 372
 373                 case OP_31_XOP_DCBF:
 374                 case OP_31_XOP_DCBI:
 375                         /* Do nothing. The guest is performing dcbi because
 376                          * hardware DMA is not snooped by the dcache, but
 377                          * emulated DMA either goes through the dcache as
 378                          * normal writes, or the host kernel has handled dcache
 379                          * coherence. */
 380                         break;
 381
 382                 case OP_31_XOP_LWBRX:
 383                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 384                         break;
 385
 386                 case OP_31_XOP_TLBSYNC:
 387                         break;
 388
 389                 case OP_31_XOP_STWBRX:
 390                         emulated = kvmppc_handle_store(run, vcpu,
 391                                                        kvmppc_get_gpr(vcpu, rs),
 392                                                        4, 0);
 393                         break;
 394
 395                 case OP_31_XOP_LHBRX:
 396                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 397                         break;
 398
 399                 case OP_31_XOP_STHBRX:
 400                         emulated = kvmppc_handle_store(run, vcpu,
 401                                                        kvmppc_get_gpr(vcpu, rs),
 402                                                        2, 0);
 403                         break;
 404
 405                 default:
 406                         /* Attempt core-specific emulation below. */
 407                         emulated = EMULATE_FAIL;
 408                 }
 409                 break;
 410
 411         case OP_LWZ:
 412                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 413                 break;
 414
 415         /* TBD: Add support for other 64 bit load variants like ldu, ldux, ldx etc. */
 416         case OP_LD:
 417                 rt = get_rt(inst);
 418                 emulated = kvmppc_handle_load(run, vcpu, rt, 8, 1);
 419                 break;
 420
 421         case OP_LWZU:
 422                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 423                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 424                 break;
 425
 426         case OP_LBZ:
 427                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 428                 break;
 429
 430         case OP_LBZU:
 431                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 432                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 433                 break;
 434
 435         case OP_STW:
 436                 emulated = kvmppc_handle_store(run, vcpu,
 437                                                kvmppc_get_gpr(vcpu, rs),
 438                                                4, 1);
 439                 break;
 440
 441         /* TBD: Add support for other 64 bit store variants like stdu, stdux, stdx etc. */
 442         case OP_STD:
 443                 rs = get_rs(inst);
 444                 emulated = kvmppc_handle_store(run, vcpu,
 445                                                kvmppc_get_gpr(vcpu, rs),
 446                                                8, 1);
 447                 break;
 448
 449         case OP_STWU:
 450                 emulated = kvmppc_handle_store(run, vcpu,
 451                                                kvmppc_get_gpr(vcpu, rs),
 452                                                4, 1);
 453                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 454                 break;
 455
 456         case OP_STB:
 457                 emulated = kvmppc_handle_store(run, vcpu,
 458                                                kvmppc_get_gpr(vcpu, rs),
 459                                                1, 1);
 460                 break;
 461
 462         case OP_STBU:
 463                 emulated = kvmppc_handle_store(run, vcpu,
 464                                                kvmppc_get_gpr(vcpu, rs),
 465                                                1, 1);
 466                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 467                 break;
 468
 469         case OP_LHZ:
 470                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 471                 break;
 472
 473         case OP_LHZU:
 474                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 475                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 476                 break;
 477
 478         case OP_LHA:
 479                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 480                 break;
 481
 482         case OP_LHAU:
 483                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 484                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 485                 break;
 486
 487         case OP_STH:
 488                 emulated = kvmppc_handle_store(run, vcpu,
 489                                                kvmppc_get_gpr(vcpu, rs),
 490                                                2, 1);
 491                 break;
 492
 493         case OP_STHU:
 494                 emulated = kvmppc_handle_store(run, vcpu,
 495                                                kvmppc_get_gpr(vcpu, rs),
 496                                                2, 1);
 497                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 498                 break;
 499
 500         default:
 501                 emulated = EMULATE_FAIL;
 502         }
 503
 504         if (emulated == EMULATE_FAIL) {
 505                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 506                 if (emulated == EMULATE_AGAIN) {
 507                         advance = 0;
 508                 } else if (emulated == EMULATE_FAIL) {
 509                         advance = 0;
 510                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 511                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 512                         kvmppc_core_queue_program(vcpu, 0);
 513                 }
 514         }
 515
 516         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 517
 518         /* Advance past emulated instruction. */
 519         if (advance)
 520                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 521
 522         return emulated;
 523 }