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/timer.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
  33 #define OP_TRAP 3
  34
  35 #define OP_31_XOP_LWZX      23
  36 #define OP_31_XOP_LBZX      87
  37 #define OP_31_XOP_STWX      151
  38 #define OP_31_XOP_STBX      215
  39 #define OP_31_XOP_STBUX     247
  40 #define OP_31_XOP_LHZX      279
  41 #define OP_31_XOP_LHZUX     311
  42 #define OP_31_XOP_MFSPR     339
  43 #define OP_31_XOP_STHX      407
  44 #define OP_31_XOP_STHUX     439
  45 #define OP_31_XOP_MTSPR     467
  46 #define OP_31_XOP_DCBI      470
  47 #define OP_31_XOP_LWBRX     534
  48 #define OP_31_XOP_TLBSYNC   566
  49 #define OP_31_XOP_STWBRX    662
  50 #define OP_31_XOP_LHBRX     790
  51 #define OP_31_XOP_STHBRX    918
  52
  53 #define OP_LWZ  32
  54 #define OP_LWZU 33
  55 #define OP_LBZ  34
  56 #define OP_LBZU 35
  57 #define OP_STW  36
  58 #define OP_STWU 37
  59 #define OP_STB  38
  60 #define OP_STBU 39
  61 #define OP_LHZ  40
  62 #define OP_LHZU 41
  63 #define OP_STH  44
  64 #define OP_STHU 45
  65
  66 void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
  67 {
  68         if (vcpu->arch.tcr & TCR_DIE) {
  69                 /* The decrementer ticks at the same rate as the timebase, so
  70                  * that's how we convert the guest DEC value to the number of
  71                  * host ticks. */
  72                 unsigned long nr_jiffies;
  73
  74                 nr_jiffies = vcpu->arch.dec / tb_ticks_per_jiffy;
  75                 mod_timer(&vcpu->arch.dec_timer,
  76                           get_jiffies_64() + nr_jiffies);
  77         } else {
  78                 del_timer(&vcpu->arch.dec_timer);
  79         }
  80 }
  81
  82 /* XXX to do:
  83  * lhax
  84  * lhaux
  85  * lswx
  86  * lswi
  87  * stswx
  88  * stswi
  89  * lha
  90  * lhau
  91  * lmw
  92  * stmw
  93  *
  94  * XXX is_bigendian should depend on MMU mapping or MSR[LE]
  95  */
  96 /* XXX Should probably auto-generate instruction decoding for a particular core
  97  * from opcode tables in the future. */
  98 int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
  99 {
 100         u32 inst = vcpu->arch.last_inst;
 101         u32 ea;
 102         int ra;
 103         int rb;
 104         int rs;
 105         int rt;
 106         int sprn;
 107         enum emulation_result emulated = EMULATE_DONE;
 108         int advance = 1;
 109
 110         /* this default type might be overwritten by subcategories */
 111         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
 112
 113         switch (get_op(inst)) {
 114         case OP_TRAP:
 115                 vcpu->arch.esr |= ESR_PTR;
 116                 kvmppc_core_queue_program(vcpu);
 117                 advance = 0;
 118                 break;
 119
 120         case 31:
 121                 switch (get_xop(inst)) {
 122
 123                 case OP_31_XOP_LWZX:
 124                         rt = get_rt(inst);
 125                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 126                         break;
 127
 128                 case OP_31_XOP_LBZX:
 129                         rt = get_rt(inst);
 130                         emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 131                         break;
 132
 133                 case OP_31_XOP_STWX:
 134                         rs = get_rs(inst);
 135                         emulated = kvmppc_handle_store(run, vcpu,
 136                                                        vcpu->arch.gpr[rs],
 137                                                        4, 1);
 138                         break;
 139
 140                 case OP_31_XOP_STBX:
 141                         rs = get_rs(inst);
 142                         emulated = kvmppc_handle_store(run, vcpu,
 143                                                        vcpu->arch.gpr[rs],
 144                                                        1, 1);
 145                         break;
 146
 147                 case OP_31_XOP_STBUX:
 148                         rs = get_rs(inst);
 149                         ra = get_ra(inst);
 150                         rb = get_rb(inst);
 151
 152                         ea = vcpu->arch.gpr[rb];
 153                         if (ra)
 154                                 ea += vcpu->arch.gpr[ra];
 155
 156                         emulated = kvmppc_handle_store(run, vcpu,
 157                                                        vcpu->arch.gpr[rs],
 158                                                        1, 1);
 159                         vcpu->arch.gpr[rs] = ea;
 160                         break;
 161
 162                 case OP_31_XOP_LHZX:
 163                         rt = get_rt(inst);
 164                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 165                         break;
 166
 167                 case OP_31_XOP_LHZUX:
 168                         rt = get_rt(inst);
 169                         ra = get_ra(inst);
 170                         rb = get_rb(inst);
 171
 172                         ea = vcpu->arch.gpr[rb];
 173                         if (ra)
 174                                 ea += vcpu->arch.gpr[ra];
 175
 176                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 177                         vcpu->arch.gpr[ra] = ea;
 178                         break;
 179
 180                 case OP_31_XOP_MFSPR:
 181                         sprn = get_sprn(inst);
 182                         rt = get_rt(inst);
 183
 184                         switch (sprn) {
 185                         case SPRN_SRR0:
 186                                 vcpu->arch.gpr[rt] = vcpu->arch.srr0; break;
 187                         case SPRN_SRR1:
 188                                 vcpu->arch.gpr[rt] = vcpu->arch.srr1; break;
 189                         case SPRN_PVR:
 190                                 vcpu->arch.gpr[rt] = vcpu->arch.pvr; break;
 191
 192                         /* Note: mftb and TBRL/TBWL are user-accessible, so
 193                          * the guest can always access the real TB anyways.
 194                          * In fact, we probably will never see these traps. */
 195                         case SPRN_TBWL:
 196                                 vcpu->arch.gpr[rt] = mftbl(); break;
 197                         case SPRN_TBWU:
 198                                 vcpu->arch.gpr[rt] = mftbu(); break;
 199
 200                         case SPRN_SPRG0:
 201                                 vcpu->arch.gpr[rt] = vcpu->arch.sprg0; break;
 202                         case SPRN_SPRG1:
 203                                 vcpu->arch.gpr[rt] = vcpu->arch.sprg1; break;
 204                         case SPRN_SPRG2:
 205                                 vcpu->arch.gpr[rt] = vcpu->arch.sprg2; break;
 206                         case SPRN_SPRG3:
 207                                 vcpu->arch.gpr[rt] = vcpu->arch.sprg3; break;
 208                         /* Note: SPRG4-7 are user-readable, so we don't get
 209                          * a trap. */
 210
 211                         default:
 212                                 emulated = kvmppc_core_emulate_mfspr(vcpu, sprn, rt);
 213                                 if (emulated == EMULATE_FAIL) {
 214                                         printk("mfspr: unknown spr %x\n", sprn);
 215                                         vcpu->arch.gpr[rt] = 0;
 216                                 }
 217                                 break;
 218                         }
 219                         break;
 220
 221                 case OP_31_XOP_STHX:
 222                         rs = get_rs(inst);
 223                         ra = get_ra(inst);
 224                         rb = get_rb(inst);
 225
 226                         emulated = kvmppc_handle_store(run, vcpu,
 227                                                        vcpu->arch.gpr[rs],
 228                                                        2, 1);
 229                         break;
 230
 231                 case OP_31_XOP_STHUX:
 232                         rs = get_rs(inst);
 233                         ra = get_ra(inst);
 234                         rb = get_rb(inst);
 235
 236                         ea = vcpu->arch.gpr[rb];
 237                         if (ra)
 238                                 ea += vcpu->arch.gpr[ra];
 239
 240                         emulated = kvmppc_handle_store(run, vcpu,
 241                                                        vcpu->arch.gpr[rs],
 242                                                        2, 1);
 243                         vcpu->arch.gpr[ra] = ea;
 244                         break;
 245
 246                 case OP_31_XOP_MTSPR:
 247                         sprn = get_sprn(inst);
 248                         rs = get_rs(inst);
 249                         switch (sprn) {
 250                         case SPRN_SRR0:
 251                                 vcpu->arch.srr0 = vcpu->arch.gpr[rs]; break;
 252                         case SPRN_SRR1:
 253                                 vcpu->arch.srr1 = vcpu->arch.gpr[rs]; break;
 254
 255                         /* XXX We need to context-switch the timebase for
 256                          * watchdog and FIT. */
 257                         case SPRN_TBWL: break;
 258                         case SPRN_TBWU: break;
 259
 260                         case SPRN_DEC:
 261                                 vcpu->arch.dec = vcpu->arch.gpr[rs];
 262                                 kvmppc_emulate_dec(vcpu);
 263                                 break;
 264
 265                         case SPRN_SPRG0:
 266                                 vcpu->arch.sprg0 = vcpu->arch.gpr[rs]; break;
 267                         case SPRN_SPRG1:
 268                                 vcpu->arch.sprg1 = vcpu->arch.gpr[rs]; break;
 269                         case SPRN_SPRG2:
 270                                 vcpu->arch.sprg2 = vcpu->arch.gpr[rs]; break;
 271                         case SPRN_SPRG3:
 272                                 vcpu->arch.sprg3 = vcpu->arch.gpr[rs]; break;
 273
 274                         default:
 275                                 emulated = kvmppc_core_emulate_mtspr(vcpu, sprn, rs);
 276                                 if (emulated == EMULATE_FAIL)
 277                                         printk("mtspr: unknown spr %x\n", sprn);
 278                                 break;
 279                         }
 280                         break;
 281
 282                 case OP_31_XOP_DCBI:
 283                         /* Do nothing. The guest is performing dcbi because
 284                          * hardware DMA is not snooped by the dcache, but
 285                          * emulated DMA either goes through the dcache as
 286                          * normal writes, or the host kernel has handled dcache
 287                          * coherence. */
 288                         break;
 289
 290                 case OP_31_XOP_LWBRX:
 291                         rt = get_rt(inst);
 292                         emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
 293                         break;
 294
 295                 case OP_31_XOP_TLBSYNC:
 296                         break;
 297
 298                 case OP_31_XOP_STWBRX:
 299                         rs = get_rs(inst);
 300                         ra = get_ra(inst);
 301                         rb = get_rb(inst);
 302
 303                         emulated = kvmppc_handle_store(run, vcpu,
 304                                                        vcpu->arch.gpr[rs],
 305                                                        4, 0);
 306                         break;
 307
 308                 case OP_31_XOP_LHBRX:
 309                         rt = get_rt(inst);
 310                         emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
 311                         break;
 312
 313                 case OP_31_XOP_STHBRX:
 314                         rs = get_rs(inst);
 315                         ra = get_ra(inst);
 316                         rb = get_rb(inst);
 317
 318                         emulated = kvmppc_handle_store(run, vcpu,
 319                                                        vcpu->arch.gpr[rs],
 320                                                        2, 0);
 321                         break;
 322
 323                 default:
 324                         /* Attempt core-specific emulation below. */
 325                         emulated = EMULATE_FAIL;
 326                 }
 327                 break;
 328
 329         case OP_LWZ:
 330                 rt = get_rt(inst);
 331                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 332                 break;
 333
 334         case OP_LWZU:
 335                 ra = get_ra(inst);
 336                 rt = get_rt(inst);
 337                 emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
 338                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 339                 break;
 340
 341         case OP_LBZ:
 342                 rt = get_rt(inst);
 343                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 344                 break;
 345
 346         case OP_LBZU:
 347                 ra = get_ra(inst);
 348                 rt = get_rt(inst);
 349                 emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
 350                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 351                 break;
 352
 353         case OP_STW:
 354                 rs = get_rs(inst);
 355                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 356                                                4, 1);
 357                 break;
 358
 359         case OP_STWU:
 360                 ra = get_ra(inst);
 361                 rs = get_rs(inst);
 362                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 363                                                4, 1);
 364                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 365                 break;
 366
 367         case OP_STB:
 368                 rs = get_rs(inst);
 369                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 370                                                1, 1);
 371                 break;
 372
 373         case OP_STBU:
 374                 ra = get_ra(inst);
 375                 rs = get_rs(inst);
 376                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 377                                                1, 1);
 378                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 379                 break;
 380
 381         case OP_LHZ:
 382                 rt = get_rt(inst);
 383                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 384                 break;
 385
 386         case OP_LHZU:
 387                 ra = get_ra(inst);
 388                 rt = get_rt(inst);
 389                 emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
 390                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 391                 break;
 392
 393         case OP_STH:
 394                 rs = get_rs(inst);
 395                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 396                                                2, 1);
 397                 break;
 398
 399         case OP_STHU:
 400                 ra = get_ra(inst);
 401                 rs = get_rs(inst);
 402                 emulated = kvmppc_handle_store(run, vcpu, vcpu->arch.gpr[rs],
 403                                                2, 1);
 404                 vcpu->arch.gpr[ra] = vcpu->arch.paddr_accessed;
 405                 break;
 406
 407         default:
 408                 emulated = EMULATE_FAIL;
 409         }
 410
 411         if (emulated == EMULATE_FAIL) {
 412                 emulated = kvmppc_core_emulate_op(run, vcpu, inst, &advance);
 413                 if (emulated == EMULATE_FAIL) {
 414                         advance = 0;
 415                         printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 416                                "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
 417                 }
 418         }
 419
 420         KVMTRACE_3D(PPC_INSTR, vcpu, inst, (int)vcpu->arch.pc, emulated, entryexit);
 421
 422         if (advance)
 423                 vcpu->arch.pc += 4; /* Advance past emulated instruction. */
 424
 425         return emulated;
 426 }