arch/powerpc/kvm/emulate_loadstore.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 <asm/ppc-opcode.h>
  34 #include <asm/sstep.h>
  35 #include "timing.h"
  36 #include "trace.h"
  37
  38 #ifdef CONFIG_PPC_FPU
  39 static bool kvmppc_check_fp_disabled(struct kvm_vcpu *vcpu)
  40 {
  41         if (!(kvmppc_get_msr(vcpu) & MSR_FP)) {
  42                 kvmppc_core_queue_fpunavail(vcpu);
  43                 return true;
  44         }
  45
  46         return false;
  47 }
  48 #endif /* CONFIG_PPC_FPU */
  49
  50 #ifdef CONFIG_VSX
  51 static bool kvmppc_check_vsx_disabled(struct kvm_vcpu *vcpu)
  52 {
  53         if (!(kvmppc_get_msr(vcpu) & MSR_VSX)) {
  54                 kvmppc_core_queue_vsx_unavail(vcpu);
  55                 return true;
  56         }
  57
  58         return false;
  59 }
  60 #endif /* CONFIG_VSX */
  61
  62 #ifdef CONFIG_ALTIVEC
  63 static bool kvmppc_check_altivec_disabled(struct kvm_vcpu *vcpu)
  64 {
  65         if (!(kvmppc_get_msr(vcpu) & MSR_VEC)) {
  66                 kvmppc_core_queue_vec_unavail(vcpu);
  67                 return true;
  68         }
  69
  70         return false;
  71 }
  72 #endif /* CONFIG_ALTIVEC */
  73
  74 /*
  75  * XXX to do:
  76  * lfiwax, lfiwzx
  77  * vector loads and stores
  78  *
  79  * Instructions that trap when used on cache-inhibited mappings
  80  * are not emulated here: multiple and string instructions,
  81  * lq/stq, and the load-reserve/store-conditional instructions.
  82  */
  83 int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
  84 {
  85         struct kvm_run *run = vcpu->run;
  86         u32 inst;
  87         int ra, rs, rt;
  88         enum emulation_result emulated = EMULATE_FAIL;
  89         int advance = 1;
  90         struct instruction_op op;
  91
  92         /* this default type might be overwritten by subcategories */
  93         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
  94
  95         emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
  96         if (emulated != EMULATE_DONE)
  97                 return emulated;
  98
  99         ra = get_ra(inst);
 100         rs = get_rs(inst);
 101         rt = get_rt(inst);
 102
 103         /*
 104          * if mmio_vsx_tx_sx_enabled == 0, copy data between
 105          * VSR[0..31] and memory
 106          * if mmio_vsx_tx_sx_enabled == 1, copy data between
 107          * VSR[32..63] and memory
 108          */
 109         vcpu->arch.mmio_vsx_copy_nums = 0;
 110         vcpu->arch.mmio_vsx_offset = 0;
 111         vcpu->arch.mmio_copy_type = KVMPPC_VSX_COPY_NONE;
 112         vcpu->arch.mmio_sp64_extend = 0;
 113         vcpu->arch.mmio_sign_extend = 0;
 114         vcpu->arch.mmio_vmx_copy_nums = 0;
 115         vcpu->arch.mmio_vmx_offset = 0;
 116         vcpu->arch.mmio_host_swabbed = 0;
 117
 118         emulated = EMULATE_FAIL;
 119         vcpu->arch.regs.msr = vcpu->arch.shared->msr;
 120         if (analyse_instr(&op, &vcpu->arch.regs, inst) == 0) {
 121                 int type = op.type & INSTR_TYPE_MASK;
 122                 int size = GETSIZE(op.type);
 123
 124                 switch (type) {
 125                 case LOAD:  {
 126                         int instr_byte_swap = op.type & BYTEREV;
 127
 128                         if (op.type & SIGNEXT)
 129                                 emulated = kvmppc_handle_loads(run, vcpu,
 130                                                 op.reg, size, !instr_byte_swap);
 131                         else
 132                                 emulated = kvmppc_handle_load(run, vcpu,
 133                                                 op.reg, size, !instr_byte_swap);
 134
 135                         if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 136                                 kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 137
 138                         break;
 139                 }
 140 #ifdef CONFIG_PPC_FPU
 141                 case LOAD_FP:
 142                         if (kvmppc_check_fp_disabled(vcpu))
 143                                 return EMULATE_DONE;
 144
 145                         if (op.type & FPCONV)
 146                                 vcpu->arch.mmio_sp64_extend = 1;
 147
 148                         if (op.type & SIGNEXT)
 149                                 emulated = kvmppc_handle_loads(run, vcpu,
 150                                              KVM_MMIO_REG_FPR|op.reg, size, 1);
 151                         else
 152                                 emulated = kvmppc_handle_load(run, vcpu,
 153                                              KVM_MMIO_REG_FPR|op.reg, size, 1);
 154
 155                         if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 156                                 kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 157
 158                         break;
 159 #endif
 160 #ifdef CONFIG_ALTIVEC
 161                 case LOAD_VMX:
 162                         if (kvmppc_check_altivec_disabled(vcpu))
 163                                 return EMULATE_DONE;
 164
 165                         /* Hardware enforces alignment of VMX accesses */
 166                         vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
 167                         vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
 168
 169                         if (size == 16) { /* lvx */
 170                                 vcpu->arch.mmio_copy_type =
 171                                                 KVMPPC_VMX_COPY_DWORD;
 172                         } else if (size == 4) { /* lvewx  */
 173                                 vcpu->arch.mmio_copy_type =
 174                                                 KVMPPC_VMX_COPY_WORD;
 175                         } else if (size == 2) { /* lvehx  */
 176                                 vcpu->arch.mmio_copy_type =
 177                                                 KVMPPC_VMX_COPY_HWORD;
 178                         } else if (size == 1) { /* lvebx  */
 179                                 vcpu->arch.mmio_copy_type =
 180                                                 KVMPPC_VMX_COPY_BYTE;
 181                         } else
 182                                 break;
 183
 184                         vcpu->arch.mmio_vmx_offset =
 185                                 (vcpu->arch.vaddr_accessed & 0xf)/size;
 186
 187                         if (size == 16) {
 188                                 vcpu->arch.mmio_vmx_copy_nums = 2;
 189                                 emulated = kvmppc_handle_vmx_load(run,
 190                                                 vcpu, KVM_MMIO_REG_VMX|op.reg,
 191                                                 8, 1);
 192                         } else {
 193                                 vcpu->arch.mmio_vmx_copy_nums = 1;
 194                                 emulated = kvmppc_handle_vmx_load(run, vcpu,
 195                                                 KVM_MMIO_REG_VMX|op.reg,
 196                                                 size, 1);
 197                         }
 198                         break;
 199 #endif
 200 #ifdef CONFIG_VSX
 201                 case LOAD_VSX: {
 202                         int io_size_each;
 203
 204                         if (op.vsx_flags & VSX_CHECK_VEC) {
 205                                 if (kvmppc_check_altivec_disabled(vcpu))
 206                                         return EMULATE_DONE;
 207                         } else {
 208                                 if (kvmppc_check_vsx_disabled(vcpu))
 209                                         return EMULATE_DONE;
 210                         }
 211
 212                         if (op.vsx_flags & VSX_FPCONV)
 213                                 vcpu->arch.mmio_sp64_extend = 1;
 214
 215                         if (op.element_size == 8)  {
 216                                 if (op.vsx_flags & VSX_SPLAT)
 217                                         vcpu->arch.mmio_copy_type =
 218                                                 KVMPPC_VSX_COPY_DWORD_LOAD_DUMP;
 219                                 else
 220                                         vcpu->arch.mmio_copy_type =
 221                                                 KVMPPC_VSX_COPY_DWORD;
 222                         } else if (op.element_size == 4) {
 223                                 if (op.vsx_flags & VSX_SPLAT)
 224                                         vcpu->arch.mmio_copy_type =
 225                                                 KVMPPC_VSX_COPY_WORD_LOAD_DUMP;
 226                                 else
 227                                         vcpu->arch.mmio_copy_type =
 228                                                 KVMPPC_VSX_COPY_WORD;
 229                         } else
 230                                 break;
 231
 232                         if (size < op.element_size) {
 233                                 /* precision convert case: lxsspx, etc */
 234                                 vcpu->arch.mmio_vsx_copy_nums = 1;
 235                                 io_size_each = size;
 236                         } else { /* lxvw4x, lxvd2x, etc */
 237                                 vcpu->arch.mmio_vsx_copy_nums =
 238                                         size/op.element_size;
 239                                 io_size_each = op.element_size;
 240                         }
 241
 242                         emulated = kvmppc_handle_vsx_load(run, vcpu,
 243                                         KVM_MMIO_REG_VSX|op.reg, io_size_each,
 244                                         1, op.type & SIGNEXT);
 245                         break;
 246                 }
 247 #endif
 248                 case STORE:
 249                         /* if need byte reverse, op.val has been reversed by
 250                          * analyse_instr().
 251                          */
 252                         emulated = kvmppc_handle_store(run, vcpu, op.val,
 253                                         size, 1);
 254
 255                         if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 256                                 kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 257
 258                         break;
 259 #ifdef CONFIG_PPC_FPU
 260                 case STORE_FP:
 261                         if (kvmppc_check_fp_disabled(vcpu))
 262                                 return EMULATE_DONE;
 263
 264                         /* The FP registers need to be flushed so that
 265                          * kvmppc_handle_store() can read actual FP vals
 266                          * from vcpu->arch.
 267                          */
 268                         if (vcpu->kvm->arch.kvm_ops->giveup_ext)
 269                                 vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
 270                                                 MSR_FP);
 271
 272                         if (op.type & FPCONV)
 273                                 vcpu->arch.mmio_sp64_extend = 1;
 274
 275                         emulated = kvmppc_handle_store(run, vcpu,
 276                                         VCPU_FPR(vcpu, op.reg), size, 1);
 277
 278                         if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 279                                 kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 280
 281                         break;
 282 #endif
 283 #ifdef CONFIG_ALTIVEC
 284                 case STORE_VMX:
 285                         if (kvmppc_check_altivec_disabled(vcpu))
 286                                 return EMULATE_DONE;
 287
 288                         /* Hardware enforces alignment of VMX accesses. */
 289                         vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
 290                         vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
 291
 292                         if (vcpu->kvm->arch.kvm_ops->giveup_ext)
 293                                 vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
 294                                                 MSR_VEC);
 295                         if (size == 16) { /* stvx */
 296                                 vcpu->arch.mmio_copy_type =
 297                                                 KVMPPC_VMX_COPY_DWORD;
 298                         } else if (size == 4) { /* stvewx  */
 299                                 vcpu->arch.mmio_copy_type =
 300                                                 KVMPPC_VMX_COPY_WORD;
 301                         } else if (size == 2) { /* stvehx  */
 302                                 vcpu->arch.mmio_copy_type =
 303                                                 KVMPPC_VMX_COPY_HWORD;
 304                         } else if (size == 1) { /* stvebx  */
 305                                 vcpu->arch.mmio_copy_type =
 306                                                 KVMPPC_VMX_COPY_BYTE;
 307                         } else
 308                                 break;
 309
 310                         vcpu->arch.mmio_vmx_offset =
 311                                 (vcpu->arch.vaddr_accessed & 0xf)/size;
 312
 313                         if (size == 16) {
 314                                 vcpu->arch.mmio_vmx_copy_nums = 2;
 315                                 emulated = kvmppc_handle_vmx_store(run,
 316                                                 vcpu, op.reg, 8, 1);
 317                         } else {
 318                                 vcpu->arch.mmio_vmx_copy_nums = 1;
 319                                 emulated = kvmppc_handle_vmx_store(run,
 320                                                 vcpu, op.reg, size, 1);
 321                         }
 322
 323                         break;
 324 #endif
 325 #ifdef CONFIG_VSX
 326                 case STORE_VSX: {
 327                         int io_size_each;
 328
 329                         if (op.vsx_flags & VSX_CHECK_VEC) {
 330                                 if (kvmppc_check_altivec_disabled(vcpu))
 331                                         return EMULATE_DONE;
 332                         } else {
 333                                 if (kvmppc_check_vsx_disabled(vcpu))
 334                                         return EMULATE_DONE;
 335                         }
 336
 337                         if (vcpu->kvm->arch.kvm_ops->giveup_ext)
 338                                 vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
 339                                                 MSR_VSX);
 340
 341                         if (op.vsx_flags & VSX_FPCONV)
 342                                 vcpu->arch.mmio_sp64_extend = 1;
 343
 344                         if (op.element_size == 8)
 345                                 vcpu->arch.mmio_copy_type =
 346                                                 KVMPPC_VSX_COPY_DWORD;
 347                         else if (op.element_size == 4)
 348                                 vcpu->arch.mmio_copy_type =
 349                                                 KVMPPC_VSX_COPY_WORD;
 350                         else
 351                                 break;
 352
 353                         if (size < op.element_size) {
 354                                 /* precise conversion case, like stxsspx */
 355                                 vcpu->arch.mmio_vsx_copy_nums = 1;
 356                                 io_size_each = size;
 357                         } else { /* stxvw4x, stxvd2x, etc */
 358                                 vcpu->arch.mmio_vsx_copy_nums =
 359                                                 size/op.element_size;
 360                                 io_size_each = op.element_size;
 361                         }
 362
 363                         emulated = kvmppc_handle_vsx_store(run, vcpu,
 364                                         op.reg, io_size_each, 1);
 365                         break;
 366                 }
 367 #endif
 368                 case CACHEOP:
 369                         /* Do nothing. The guest is performing dcbi because
 370                          * hardware DMA is not snooped by the dcache, but
 371                          * emulated DMA either goes through the dcache as
 372                          * normal writes, or the host kernel has handled dcache
 373                          * coherence.
 374                          */
 375                         emulated = EMULATE_DONE;
 376                         break;
 377                 default:
 378                         break;
 379                 }
 380         }
 381
 382         if (emulated == EMULATE_FAIL) {
 383                 advance = 0;
 384                 kvmppc_core_queue_program(vcpu, 0);
 385         }
 386
 387         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 388
 389         /* Advance past emulated instruction. */
 390         if (advance)
 391                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 392
 393         return emulated;
 394 }