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_LBZX      87
  43 #define OP_31_XOP_STWX      151
  44 #define OP_31_XOP_STBX      215
  45 #define OP_31_XOP_LBZUX     119
  46 #define OP_31_XOP_STBUX     247
  47 #define OP_31_XOP_LHZX      279
  48 #define OP_31_XOP_LHZUX     311
  49 #define OP_31_XOP_MFSPR     339
  50 #define OP_31_XOP_LHAX      343
  51 #define OP_31_XOP_STHX      407
  52 #define OP_31_XOP_STHUX     439
  53 #define OP_31_XOP_MTSPR     467
  54 #define OP_31_XOP_DCBI      470
  55 #define OP_31_XOP_LWBRX     534
  56 #define OP_31_XOP_TLBSYNC   566
  57 #define OP_31_XOP_STWBRX    662
  58 #define OP_31_XOP_LHBRX     790
  59 #define OP_31_XOP_STHBRX    918
  60
  61 #define OP_LWZ  32
  62 #define OP_LD   58
  63 #define OP_LWZU 33
  64 #define OP_LBZ  34
  65 #define OP_LBZU 35
  66 #define OP_STW  36
  67 #define OP_STWU 37
  68 #define OP_STD  62
  69 #define OP_STB  38
  70 #define OP_STBU 39
  71 #define OP_LHZ  40
  72 #define OP_LHZU 41
  73 #define OP_LHA  42
  74 #define OP_LHAU 43
  75 #define OP_STH  44
  76 #define OP_STHU 45
  77
  78 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  79 {
  80         unsigned long dec_nsec;
  81         unsigned long long dec_time;
  82
  83         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
  84         hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
  85
  86 #ifdef CONFIG_PPC_BOOK3S
  87         /* mtdec lowers the interrupt line when positive. */
  88         kvmppc_core_dequeue_dec(vcpu);
  89
  90         /* POWER4+ triggers a dec interrupt if the value is < 0 */
  91         if (vcpu->arch.dec & 0x80000000) {
  92                 kvmppc_core_queue_dec(vcpu);
  93                 return;
  94         }
  95 #endif
  96
  97 #ifdef CONFIG_BOOKE
  98         /* On BOOKE, DEC = 0 is as good as decrementer not enabled */
  99         if (vcpu->arch.dec == 0)
 100                 return;
 101 #endif
 102
 103         /*
 104          * The decrementer ticks at the same rate as the timebase, so
 105          * that's how we convert the guest DEC value to the number of
 106          * host ticks.
 107          */
 108
 109         dec_time = vcpu->arch.dec;
 110         /*
 111          * Guest timebase ticks at the same frequency as host decrementer.
 112          * So use the host decrementer calculations for decrementer emulation.
 113          */
 114         dec_time = dec_time << decrementer_clockevent.shift;
 115         do_div(dec_time, decrementer_clockevent.mult);
 116         dec_nsec = do_div(dec_time, NSEC_PER_SEC);
 117         hrtimer_start(&vcpu->arch.dec_timer,
 118                 ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
 119         vcpu->arch.dec_jiffies = get_tb();
 120 }
 121
 122 u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 123 {
 124         u64 jd = tb - vcpu->arch.dec_jiffies;
 125
 126 #ifdef CONFIG_BOOKE
 127         if (vcpu->arch.dec < jd)
 128                 return 0;
 129 #endif
 130
 131         return vcpu->arch.dec - jd;
 132 }
 133
 134 static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
 135 {
 136         enum emulation_result emulated = EMULATE_DONE;
 137         ulong spr_val = kvmppc_get_gpr(vcpu, rs);
 138
 139         switch (sprn) {
 140         case SPRN_SRR0:
 141                 vcpu->arch.shared->srr0 = spr_val;
 142                 break;
 143         case SPRN_SRR1:
 144                 vcpu->arch.shared->srr1 = spr_val;
 145                 break;
 146
 147         /* XXX We need to context-switch the timebase for
 148          * watchdog and FIT. */
 149         case SPRN_TBWL: break;
 150         case SPRN_TBWU: break;
 151
 152         case SPRN_MSSSR0: break;
 153
 154         case SPRN_DEC:
 155                 vcpu->arch.dec = spr_val;
 156                 kvmppc_emulate_dec(vcpu);
 157                 break;
 158
 159         case SPRN_SPRG0:
 160                 vcpu->arch.shared->sprg0 = spr_val;
 161                 break;
 162         case SPRN_SPRG1:
 163                 vcpu->arch.shared->sprg1 = spr_val;
 164                 break;
 165         case SPRN_SPRG2:
 166                 vcpu->arch.shared->sprg2 = spr_val;
 167                 break;
 168         case SPRN_SPRG3:
 169                 vcpu->arch.shared->sprg3 = spr_val;
 170                 break;
 171
 172         default:
 173                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn,
 174                                                      spr_val);
 175                 if (emulated == EMULATE_FAIL)
 176                         printk(KERN_INFO "mtspr: unknown spr "
 177                                 "0x%x\n", sprn);
 178                 break;
 179         }
 180
 181         kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
 182
 183         return emulated;
 184 }
 185
 186 static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
 187 {
 188         enum emulation_result emulated = EMULATE_DONE;
 189         ulong spr_val = 0;
 190
 191         switch (sprn) {
 192         case SPRN_SRR0:
 193                 spr_val = vcpu->arch.shared->srr0;
 194                 break;
 195         case SPRN_SRR1:
 196                 spr_val = vcpu->arch.shared->srr1;
 197                 break;
 198         case SPRN_PVR:
 199                 spr_val = vcpu->arch.pvr;
 200                 break;
 201         case SPRN_PIR:
 202                 spr_val = vcpu->vcpu_id;
 203                 break;
 204         case SPRN_MSSSR0:
 205                 spr_val = 0;
 206                 break;
 207
 208         /* Note: mftb and TBRL/TBWL are user-accessible, so
 209          * the guest can always access the real TB anyways.
 210          * In fact, we probably will never see these traps. */
 211         case SPRN_TBWL:
 212                 spr_val = get_tb() >> 32;
 213                 break;
 214         case SPRN_TBWU:
 215                 spr_val = get_tb();
 216                 break;
 217
 218         case SPRN_SPRG0:
 219                 spr_val = vcpu->arch.shared->sprg0;
 220                 break;
 221         case SPRN_SPRG1:
 222                 spr_val = vcpu->arch.shared->sprg1;
 223                 break;
 224         case SPRN_SPRG2:
 225                 spr_val = vcpu->arch.shared->sprg2;
 226                 break;
 227         case SPRN_SPRG3:
 228                 spr_val = vcpu->arch.shared->sprg3;
 229                 break;
 230         /* Note: SPRG4-7 are user-readable, so we don't get
 231          * a trap. */
 232
 233         case SPRN_DEC:
 234                 spr_val = kvmppc_get_dec(vcpu, get_tb());
 235                 break;
 236         default:
 237                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn,
 238                                                      &spr_val);
 239                 if (unlikely(emulated == EMULATE_FAIL)) {
 240                         printk(KERN_INFO "mfspr: unknown spr "
 241                                 "0x%x\n", sprn);
 242                 }
 243                 break;
 244         }
 245
 246         if (emulated == EMULATE_DONE)
 247                 kvmppc_set_gpr(vcpu, rt, spr_val);
 248         kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
 249
 250         return emulated;
 251 }
 252
 253 /* XXX to do:
 254  * lhax
 255  * lhaux
 256  * lswx
 257  * lswi
 258  * stswx
 259  * stswi
 260  * lha
 261  * lhau
 262  * lmw
 263  * stmw
 264  *
 265  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 266  */
 267 /* XXX Should probably auto-generate instruction decoding for a particular core
 268  * from opcode tables in the future. */
 269 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 270 {
 271         u32 inst = kvmppc_get_last_inst(vcpu);
 272         int ra = get_ra(inst);
 273         int rs = get_rs(inst);
 274         int rt = get_rt(inst);
 275         int sprn = get_sprn(inst);
 276         enum emulation_result emulated = EMULATE_DONE;
 277         int advance = 1;
 278
 279         /* this default type might be overwritten by subcategories */
 280         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 281
 282         pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));
 283
 284         switch (get_op(inst)) {
 285         case OP_TRAP:
 286 #ifdef CONFIG_PPC_BOOK3S
 287         case OP_TRAP_64:
 288                 kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 289 #else
 290                 kvmppc_core_queue_program(vcpu,
 291                                           vcpu->arch.shared->esr | ESR_PTR);
 292 #endif
 293                 advance = 0;
 294                 break;
 295
 296         case 31:
 297                 switch (get_xop(inst)) {
 298
 299                 case OP_31_XOP_TRAP:
 300 #ifdef CONFIG_64BIT
 301                 case OP_31_XOP_TRAP_64:
 302 #endif
 303 #ifdef CONFIG_PPC_BOOK3S
 304                         kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
 305 #else
 306                         kvmppc_core_queue_program(vcpu,
 307                                         vcpu->arch.shared->esr | ESR_PTR);
 308 #endif
 309                         advance = 0;
 310                         break;
 311                 case OP_31_XOP_LWZX:
 312                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 313                         break;
 314
 315                 case OP_31_XOP_LBZX:
 316                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 317                         break;
 318
 319                 case OP_31_XOP_LBZUX:
 320                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 321                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 322                         break;
 323
 324                 case OP_31_XOP_STWX:
 325                         emulated = kvmppc_handle_store(run, vcpu,
 326                                                        kvmppc_get_gpr(vcpu, rs),
 327                                                        4, 1);
 328                         break;
 329
 330                 case OP_31_XOP_STBX:
 331                         emulated = kvmppc_handle_store(run, vcpu,
 332                                                        kvmppc_get_gpr(vcpu, rs),
 333                                                        1, 1);
 334                         break;
 335
 336                 case OP_31_XOP_STBUX:
 337                         emulated = kvmppc_handle_store(run, vcpu,
 338                                                        kvmppc_get_gpr(vcpu, rs),
 339                                                        1, 1);
 340                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 341                         break;
 342
 343                 case OP_31_XOP_LHAX:
 344                         emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 345                         break;
 346
 347                 case OP_31_XOP_LHZX:
 348                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 349                         break;
 350
 351                 case OP_31_XOP_LHZUX:
 352                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 353                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 354                         break;
 355
 356                 case OP_31_XOP_MFSPR:
 357                         emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
 358                         break;
 359
 360                 case OP_31_XOP_STHX:
 361                         emulated = kvmppc_handle_store(run, vcpu,
 362                                                        kvmppc_get_gpr(vcpu, rs),
 363                                                        2, 1);
 364                         break;
 365
 366                 case OP_31_XOP_STHUX:
 367                         emulated = kvmppc_handle_store(run, vcpu,
 368                                                        kvmppc_get_gpr(vcpu, rs),
 369                                                        2, 1);
 370                         kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 371                         break;
 372
 373                 case OP_31_XOP_MTSPR:
 374                         emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
 375                         break;
 376
 377                 case OP_31_XOP_DCBI:
 378                         /* Do nothing. The guest is performing dcbi because
 379                          * hardware DMA is not snooped by the dcache, but
 380                          * emulated DMA either goes through the dcache as
 381                          * normal writes, or the host kernel has handled dcache
 382                          * coherence. */
 383                         break;
 384
 385                 case OP_31_XOP_LWBRX:
 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                         emulated = kvmppc_handle_store(run, vcpu,
 394                                                        kvmppc_get_gpr(vcpu, rs),
 395                                                        4, 0);
 396                         break;
 397
 398                 case OP_31_XOP_LHBRX:
 399                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 400                         break;
 401
 402                 case OP_31_XOP_STHBRX:
 403                         emulated = kvmppc_handle_store(run, vcpu,
 404                                                        kvmppc_get_gpr(vcpu, rs),
 405                                                        2, 0);
 406                         break;
 407
 408                 default:
 409                         /* Attempt core-specific emulation below. */
 410                         emulated = EMULATE_FAIL;
 411                 }
 412                 break;
 413
 414         case OP_LWZ:
 415                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 416                 break;
 417
 418         /* TBD: Add support for other 64 bit load variants like ldu, ldux, ldx etc. */
 419         case OP_LD:
 420                 rt = get_rt(inst);
 421                 emulated = kvmppc_handle_load(run, vcpu, rt, 8, 1);
 422                 break;
 423
 424         case OP_LWZU:
 425                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 426                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 427                 break;
 428
 429         case OP_LBZ:
 430                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 431                 break;
 432
 433         case OP_LBZU:
 434                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 435                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 436                 break;
 437
 438         case OP_STW:
 439                 emulated = kvmppc_handle_store(run, vcpu,
 440                                                kvmppc_get_gpr(vcpu, rs),
 441                                                4, 1);
 442                 break;
 443
 444         /* TBD: Add support for other 64 bit store variants like stdu, stdux, stdx etc. */
 445         case OP_STD:
 446                 rs = get_rs(inst);
 447                 emulated = kvmppc_handle_store(run, vcpu,
 448                                                kvmppc_get_gpr(vcpu, rs),
 449                                                8, 1);
 450                 break;
 451
 452         case OP_STWU:
 453                 emulated = kvmppc_handle_store(run, vcpu,
 454                                                kvmppc_get_gpr(vcpu, rs),
 455                                                4, 1);
 456                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 457                 break;
 458
 459         case OP_STB:
 460                 emulated = kvmppc_handle_store(run, vcpu,
 461                                                kvmppc_get_gpr(vcpu, rs),
 462                                                1, 1);
 463                 break;
 464
 465         case OP_STBU:
 466                 emulated = kvmppc_handle_store(run, vcpu,
 467                                                kvmppc_get_gpr(vcpu, rs),
 468                                                1, 1);
 469                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 470                 break;
 471
 472         case OP_LHZ:
 473                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 474                 break;
 475
 476         case OP_LHZU:
 477                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 478                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 479                 break;
 480
 481         case OP_LHA:
 482                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 483                 break;
 484
 485         case OP_LHAU:
 486                 emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
 487                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
 488                 break;
 489
 490         case OP_STH:
 491                 emulated = kvmppc_handle_store(run, vcpu,
 492                                                kvmppc_get_gpr(vcpu, rs),
 493                                                2, 1);
 494                 break;
 495
 496         case OP_STHU:
 497                 emulated = kvmppc_handle_store(run, vcpu,
 498                                                kvmppc_get_gpr(vcpu, rs),
 499                                                2, 1);
 500                 kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_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 }