arch/powerpc/kvm/emulate_loadstore.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *
   4  * Copyright IBM Corp. 2007
   5  * Copyright 2011 Freescale Semiconductor, Inc.
   6  *
   7  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
   8  */
   9
  10 #include <linux/jiffies.h>
  11 #include <linux/hrtimer.h>
  12 #include <linux/types.h>
  13 #include <linux/string.h>
  14 #include <linux/kvm_host.h>
  15 #include <linux/clockchips.h>
  16
  17 #include <asm/reg.h>
  18 #include <asm/time.h>
  19 #include <asm/byteorder.h>
  20 #include <asm/kvm_ppc.h>
  21 #include <asm/disassemble.h>
  22 #include <asm/ppc-opcode.h>
  23 #include <asm/sstep.h>
  24 #include "timing.h"
  25 #include "trace.h"
  26
  27 #ifdef CONFIG_PPC_FPU
  28 static bool kvmppc_check_fp_disabled(struct kvm_vcpu *vcpu)
  29 {
  30         if (!(kvmppc_get_msr(vcpu) & MSR_FP)) {
  31                 kvmppc_core_queue_fpunavail(vcpu);
  32                 return true;
  33         }
  34
  35         return false;
  36 }
  37 #endif /* CONFIG_PPC_FPU */
  38
  39 #ifdef CONFIG_VSX
  40 static bool kvmppc_check_vsx_disabled(struct kvm_vcpu *vcpu)
  41 {
  42         if (!(kvmppc_get_msr(vcpu) & MSR_VSX)) {
  43                 kvmppc_core_queue_vsx_unavail(vcpu);
  44                 return true;
  45         }
  46
  47         return false;
  48 }
  49 #endif /* CONFIG_VSX */
  50
  51 #ifdef CONFIG_ALTIVEC
  52 static bool kvmppc_check_altivec_disabled(struct kvm_vcpu *vcpu)
  53 {
  54         if (!(kvmppc_get_msr(vcpu) & MSR_VEC)) {
  55                 kvmppc_core_queue_vec_unavail(vcpu);
  56                 return true;
  57         }
  58
  59         return false;
  60 }
  61 #endif /* CONFIG_ALTIVEC */
  62
  63 /*
  64  * XXX to do:
  65  * lfiwax, lfiwzx
  66  * vector loads and stores
  67  *
  68  * Instructions that trap when used on cache-inhibited mappings
  69  * are not emulated here: multiple and string instructions,
  70  * lq/stq, and the load-reserve/store-conditional instructions.
  71  */
  72 int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
  73 {
  74         struct kvm_run *run = vcpu->run;
  75         u32 inst;
  76         enum emulation_result emulated = EMULATE_FAIL;
  77         int advance = 1;
  78         struct instruction_op op;
  79
  80         /* this default type might be overwritten by subcategories */
  81         kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
  82
  83         emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
  84         if (emulated != EMULATE_DONE)
  85                 return emulated;
  86
  87         vcpu->arch.mmio_vsx_copy_nums = 0;
  88         vcpu->arch.mmio_vsx_offset = 0;
  89         vcpu->arch.mmio_copy_type = KVMPPC_VSX_COPY_NONE;
  90         vcpu->arch.mmio_sp64_extend = 0;
  91         vcpu->arch.mmio_sign_extend = 0;
  92         vcpu->arch.mmio_vmx_copy_nums = 0;
  93         vcpu->arch.mmio_vmx_offset = 0;
  94         vcpu->arch.mmio_host_swabbed = 0;
  95
  96         emulated = EMULATE_FAIL;
  97         vcpu->arch.regs.msr = vcpu->arch.shared->msr;
  98         if (analyse_instr(&op, &vcpu->arch.regs, inst) == 0) {
  99                 int type = op.type & INSTR_TYPE_MASK;
 100                 int size = GETSIZE(op.type);
 101
 102                 switch (type) {
 103                 case LOAD:  {
 104                         int instr_byte_swap = op.type & BYTEREV;
 105
 106                         if (op.type & SIGNEXT)
 107                                 emulated = kvmppc_handle_loads(run, vcpu,
 108                                                 op.reg, size, !instr_byte_swap);
 109                         else
 110                                 emulated = kvmppc_handle_load(run, vcpu,
 111                                                 op.reg, size, !instr_byte_swap);
 112
 113                         if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 114                                 kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 115
 116                         break;
 117                 }
 118 #ifdef CONFIG_PPC_FPU
 119                 case LOAD_FP:
 120                         if (kvmppc_check_fp_disabled(vcpu))
 121                                 return EMULATE_DONE;
 122
 123                         if (op.type & FPCONV)
 124                                 vcpu->arch.mmio_sp64_extend = 1;
 125
 126                         if (op.type & SIGNEXT)
 127                                 emulated = kvmppc_handle_loads(run, vcpu,
 128                                              KVM_MMIO_REG_FPR|op.reg, size, 1);
 129                         else
 130                                 emulated = kvmppc_handle_load(run, vcpu,
 131                                              KVM_MMIO_REG_FPR|op.reg, size, 1);
 132
 133                         if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 134                                 kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 135
 136                         break;
 137 #endif
 138 #ifdef CONFIG_ALTIVEC
 139                 case LOAD_VMX:
 140                         if (kvmppc_check_altivec_disabled(vcpu))
 141                                 return EMULATE_DONE;
 142
 143                         /* Hardware enforces alignment of VMX accesses */
 144                         vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
 145                         vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
 146
 147                         if (size == 16) { /* lvx */
 148                                 vcpu->arch.mmio_copy_type =
 149                                                 KVMPPC_VMX_COPY_DWORD;
 150                         } else if (size == 4) { /* lvewx  */
 151                                 vcpu->arch.mmio_copy_type =
 152                                                 KVMPPC_VMX_COPY_WORD;
 153                         } else if (size == 2) { /* lvehx  */
 154                                 vcpu->arch.mmio_copy_type =
 155                                                 KVMPPC_VMX_COPY_HWORD;
 156                         } else if (size == 1) { /* lvebx  */
 157                                 vcpu->arch.mmio_copy_type =
 158                                                 KVMPPC_VMX_COPY_BYTE;
 159                         } else
 160                                 break;
 161
 162                         vcpu->arch.mmio_vmx_offset =
 163                                 (vcpu->arch.vaddr_accessed & 0xf)/size;
 164
 165                         if (size == 16) {
 166                                 vcpu->arch.mmio_vmx_copy_nums = 2;
 167                                 emulated = kvmppc_handle_vmx_load(run,
 168                                                 vcpu, KVM_MMIO_REG_VMX|op.reg,
 169                                                 8, 1);
 170                         } else {
 171                                 vcpu->arch.mmio_vmx_copy_nums = 1;
 172                                 emulated = kvmppc_handle_vmx_load(run, vcpu,
 173                                                 KVM_MMIO_REG_VMX|op.reg,
 174                                                 size, 1);
 175                         }
 176                         break;
 177 #endif
 178 #ifdef CONFIG_VSX
 179                 case LOAD_VSX: {
 180                         int io_size_each;
 181
 182                         if (op.vsx_flags & VSX_CHECK_VEC) {
 183                                 if (kvmppc_check_altivec_disabled(vcpu))
 184                                         return EMULATE_DONE;
 185                         } else {
 186                                 if (kvmppc_check_vsx_disabled(vcpu))
 187                                         return EMULATE_DONE;
 188                         }
 189
 190                         if (op.vsx_flags & VSX_FPCONV)
 191                                 vcpu->arch.mmio_sp64_extend = 1;
 192
 193                         if (op.element_size == 8)  {
 194                                 if (op.vsx_flags & VSX_SPLAT)
 195                                         vcpu->arch.mmio_copy_type =
 196                                                 KVMPPC_VSX_COPY_DWORD_LOAD_DUMP;
 197                                 else
 198                                         vcpu->arch.mmio_copy_type =
 199                                                 KVMPPC_VSX_COPY_DWORD;
 200                         } else if (op.element_size == 4) {
 201                                 if (op.vsx_flags & VSX_SPLAT)
 202                                         vcpu->arch.mmio_copy_type =
 203                                                 KVMPPC_VSX_COPY_WORD_LOAD_DUMP;
 204                                 else
 205                                         vcpu->arch.mmio_copy_type =
 206                                                 KVMPPC_VSX_COPY_WORD;
 207                         } else
 208                                 break;
 209
 210                         if (size < op.element_size) {
 211                                 /* precision convert case: lxsspx, etc */
 212                                 vcpu->arch.mmio_vsx_copy_nums = 1;
 213                                 io_size_each = size;
 214                         } else { /* lxvw4x, lxvd2x, etc */
 215                                 vcpu->arch.mmio_vsx_copy_nums =
 216                                         size/op.element_size;
 217                                 io_size_each = op.element_size;
 218                         }
 219
 220                         emulated = kvmppc_handle_vsx_load(run, vcpu,
 221                                         KVM_MMIO_REG_VSX|op.reg, io_size_each,
 222                                         1, op.type & SIGNEXT);
 223                         break;
 224                 }
 225 #endif
 226                 case STORE:
 227                         /* if need byte reverse, op.val has been reversed by
 228                          * analyse_instr().
 229                          */
 230                         emulated = kvmppc_handle_store(run, vcpu, op.val,
 231                                         size, 1);
 232
 233                         if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 234                                 kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 235
 236                         break;
 237 #ifdef CONFIG_PPC_FPU
 238                 case STORE_FP:
 239                         if (kvmppc_check_fp_disabled(vcpu))
 240                                 return EMULATE_DONE;
 241
 242                         /* The FP registers need to be flushed so that
 243                          * kvmppc_handle_store() can read actual FP vals
 244                          * from vcpu->arch.
 245                          */
 246                         if (vcpu->kvm->arch.kvm_ops->giveup_ext)
 247                                 vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
 248                                                 MSR_FP);
 249
 250                         if (op.type & FPCONV)
 251                                 vcpu->arch.mmio_sp64_extend = 1;
 252
 253                         emulated = kvmppc_handle_store(run, vcpu,
 254                                         VCPU_FPR(vcpu, op.reg), size, 1);
 255
 256                         if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 257                                 kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 258
 259                         break;
 260 #endif
 261 #ifdef CONFIG_ALTIVEC
 262                 case STORE_VMX:
 263                         if (kvmppc_check_altivec_disabled(vcpu))
 264                                 return EMULATE_DONE;
 265
 266                         /* Hardware enforces alignment of VMX accesses. */
 267                         vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
 268                         vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
 269
 270                         if (vcpu->kvm->arch.kvm_ops->giveup_ext)
 271                                 vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
 272                                                 MSR_VEC);
 273                         if (size == 16) { /* stvx */
 274                                 vcpu->arch.mmio_copy_type =
 275                                                 KVMPPC_VMX_COPY_DWORD;
 276                         } else if (size == 4) { /* stvewx  */
 277                                 vcpu->arch.mmio_copy_type =
 278                                                 KVMPPC_VMX_COPY_WORD;
 279                         } else if (size == 2) { /* stvehx  */
 280                                 vcpu->arch.mmio_copy_type =
 281                                                 KVMPPC_VMX_COPY_HWORD;
 282                         } else if (size == 1) { /* stvebx  */
 283                                 vcpu->arch.mmio_copy_type =
 284                                                 KVMPPC_VMX_COPY_BYTE;
 285                         } else
 286                                 break;
 287
 288                         vcpu->arch.mmio_vmx_offset =
 289                                 (vcpu->arch.vaddr_accessed & 0xf)/size;
 290
 291                         if (size == 16) {
 292                                 vcpu->arch.mmio_vmx_copy_nums = 2;
 293                                 emulated = kvmppc_handle_vmx_store(run,
 294                                                 vcpu, op.reg, 8, 1);
 295                         } else {
 296                                 vcpu->arch.mmio_vmx_copy_nums = 1;
 297                                 emulated = kvmppc_handle_vmx_store(run,
 298                                                 vcpu, op.reg, size, 1);
 299                         }
 300
 301                         break;
 302 #endif
 303 #ifdef CONFIG_VSX
 304                 case STORE_VSX: {
 305                         int io_size_each;
 306
 307                         if (op.vsx_flags & VSX_CHECK_VEC) {
 308                                 if (kvmppc_check_altivec_disabled(vcpu))
 309                                         return EMULATE_DONE;
 310                         } else {
 311                                 if (kvmppc_check_vsx_disabled(vcpu))
 312                                         return EMULATE_DONE;
 313                         }
 314
 315                         if (vcpu->kvm->arch.kvm_ops->giveup_ext)
 316                                 vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
 317                                                 MSR_VSX);
 318
 319                         if (op.vsx_flags & VSX_FPCONV)
 320                                 vcpu->arch.mmio_sp64_extend = 1;
 321
 322                         if (op.element_size == 8)
 323                                 vcpu->arch.mmio_copy_type =
 324                                                 KVMPPC_VSX_COPY_DWORD;
 325                         else if (op.element_size == 4)
 326                                 vcpu->arch.mmio_copy_type =
 327                                                 KVMPPC_VSX_COPY_WORD;
 328                         else
 329                                 break;
 330
 331                         if (size < op.element_size) {
 332                                 /* precise conversion case, like stxsspx */
 333                                 vcpu->arch.mmio_vsx_copy_nums = 1;
 334                                 io_size_each = size;
 335                         } else { /* stxvw4x, stxvd2x, etc */
 336                                 vcpu->arch.mmio_vsx_copy_nums =
 337                                                 size/op.element_size;
 338                                 io_size_each = op.element_size;
 339                         }
 340
 341                         emulated = kvmppc_handle_vsx_store(run, vcpu,
 342                                         op.reg, io_size_each, 1);
 343                         break;
 344                 }
 345 #endif
 346                 case CACHEOP:
 347                         /* Do nothing. The guest is performing dcbi because
 348                          * hardware DMA is not snooped by the dcache, but
 349                          * emulated DMA either goes through the dcache as
 350                          * normal writes, or the host kernel has handled dcache
 351                          * coherence.
 352                          */
 353                         emulated = EMULATE_DONE;
 354                         break;
 355                 default:
 356                         break;
 357                 }
 358         }
 359
 360         if (emulated == EMULATE_FAIL) {
 361                 advance = 0;
 362                 kvmppc_core_queue_program(vcpu, 0);
 363         }
 364
 365         trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 366
 367         /* Advance past emulated instruction. */
 368         if (advance)
 369                 kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 370
 371         return emulated;
 372 }