LXR linux/arch/powerpc/kvm/emulate

   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
  28static 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
  40static 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
  52static 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 */
  72int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
  73{
  74        u32 inst;
  75        enum emulation_result emulated = EMULATE_FAIL;
  76        int advance = 1;
  77        struct instruction_op op;
  78
  79        /* this default type might be overwritten by subcategories */
  80        kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
  81
  82        emulated = kvmppc_get_last_inst(vcpu, INST_GENERIC, &inst);
  83        if (emulated != EMULATE_DONE)
  84                return emulated;
  85
  86        vcpu->arch.mmio_vsx_copy_nums = 0;
  87        vcpu->arch.mmio_vsx_offset = 0;
  88        vcpu->arch.mmio_copy_type = KVMPPC_VSX_COPY_NONE;
  89        vcpu->arch.mmio_sp64_extend = 0;
  90        vcpu->arch.mmio_sign_extend = 0;
  91        vcpu->arch.mmio_vmx_copy_nums = 0;
  92        vcpu->arch.mmio_vmx_offset = 0;
  93        vcpu->arch.mmio_host_swabbed = 0;
  94
  95        emulated = EMULATE_FAIL;
  96        vcpu->arch.regs.msr = vcpu->arch.shared->msr;
  97        if (analyse_instr(&op, &vcpu->arch.regs, ppc_inst(inst)) == 0) {
  98                int type = op.type & INSTR_TYPE_MASK;
  99                int size = GETSIZE(op.type);
 100
 101                switch (type) {
 102                case LOAD:  {
 103                        int instr_byte_swap = op.type & BYTEREV;
 104
 105                        if (op.type & SIGNEXT)
 106                                emulated = kvmppc_handle_loads(vcpu,
 107                                                op.reg, size, !instr_byte_swap);
 108                        else
 109                                emulated = kvmppc_handle_load(vcpu,
 110                                                op.reg, size, !instr_byte_swap);
 111
 112                        if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 113                                kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 114
 115                        break;
 116                }
 117#ifdef CONFIG_PPC_FPU
 118                case LOAD_FP:
 119                        if (kvmppc_check_fp_disabled(vcpu))
 120                                return EMULATE_DONE;
 121
 122                        if (op.type & FPCONV)
 123                                vcpu->arch.mmio_sp64_extend = 1;
 124
 125                        if (op.type & SIGNEXT)
 126                                emulated = kvmppc_handle_loads(vcpu,
 127                                             KVM_MMIO_REG_FPR|op.reg, size, 1);
 128                        else
 129                                emulated = kvmppc_handle_load(vcpu,
 130                                             KVM_MMIO_REG_FPR|op.reg, size, 1);
 131
 132                        if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 133                                kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 134
 135                        break;
 136#endif
 137#ifdef CONFIG_ALTIVEC
 138                case LOAD_VMX:
 139                        if (kvmppc_check_altivec_disabled(vcpu))
 140                                return EMULATE_DONE;
 141
 142                        /* Hardware enforces alignment of VMX accesses */
 143                        vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
 144                        vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
 145
 146                        if (size == 16) { /* lvx */
 147                                vcpu->arch.mmio_copy_type =
 148                                                KVMPPC_VMX_COPY_DWORD;
 149                        } else if (size == 4) { /* lvewx  */
 150                                vcpu->arch.mmio_copy_type =
 151                                                KVMPPC_VMX_COPY_WORD;
 152                        } else if (size == 2) { /* lvehx  */
 153                                vcpu->arch.mmio_copy_type =
 154                                                KVMPPC_VMX_COPY_HWORD;
 155                        } else if (size == 1) { /* lvebx  */
 156                                vcpu->arch.mmio_copy_type =
 157                                                KVMPPC_VMX_COPY_BYTE;
 158                        } else
 159                                break;
 160
 161                        vcpu->arch.mmio_vmx_offset =
 162                                (vcpu->arch.vaddr_accessed & 0xf)/size;
 163
 164                        if (size == 16) {
 165                                vcpu->arch.mmio_vmx_copy_nums = 2;
 166                                emulated = kvmppc_handle_vmx_load(vcpu,
 167                                                KVM_MMIO_REG_VMX|op.reg,
 168                                                8, 1);
 169                        } else {
 170                                vcpu->arch.mmio_vmx_copy_nums = 1;
 171                                emulated = kvmppc_handle_vmx_load(vcpu,
 172                                                KVM_MMIO_REG_VMX|op.reg,
 173                                                size, 1);
 174                        }
 175                        break;
 176#endif
 177#ifdef CONFIG_VSX
 178                case LOAD_VSX: {
 179                        int io_size_each;
 180
 181                        if (op.vsx_flags & VSX_CHECK_VEC) {
 182                                if (kvmppc_check_altivec_disabled(vcpu))
 183                                        return EMULATE_DONE;
 184                        } else {
 185                                if (kvmppc_check_vsx_disabled(vcpu))
 186                                        return EMULATE_DONE;
 187                        }
 188
 189                        if (op.vsx_flags & VSX_FPCONV)
 190                                vcpu->arch.mmio_sp64_extend = 1;
 191
 192                        if (op.element_size == 8)  {
 193                                if (op.vsx_flags & VSX_SPLAT)
 194                                        vcpu->arch.mmio_copy_type =
 195                                                KVMPPC_VSX_COPY_DWORD_LOAD_DUMP;
 196                                else
 197                                        vcpu->arch.mmio_copy_type =
 198                                                KVMPPC_VSX_COPY_DWORD;
 199                        } else if (op.element_size == 4) {
 200                                if (op.vsx_flags & VSX_SPLAT)
 201                                        vcpu->arch.mmio_copy_type =
 202                                                KVMPPC_VSX_COPY_WORD_LOAD_DUMP;
 203                                else
 204                                        vcpu->arch.mmio_copy_type =
 205                                                KVMPPC_VSX_COPY_WORD;
 206                        } else
 207                                break;
 208
 209                        if (size < op.element_size) {
 210                                /* precision convert case: lxsspx, etc */
 211                                vcpu->arch.mmio_vsx_copy_nums = 1;
 212                                io_size_each = size;
 213                        } else { /* lxvw4x, lxvd2x, etc */
 214                                vcpu->arch.mmio_vsx_copy_nums =
 215                                        size/op.element_size;
 216                                io_size_each = op.element_size;
 217                        }
 218
 219                        emulated = kvmppc_handle_vsx_load(vcpu,
 220                                        KVM_MMIO_REG_VSX|op.reg, io_size_each,
 221                                        1, op.type & SIGNEXT);
 222                        break;
 223                }
 224#endif
 225                case STORE:
 226                        /* if need byte reverse, op.val has been reversed by
 227                         * analyse_instr().
 228                         */
 229                        emulated = kvmppc_handle_store(vcpu, op.val, size, 1);
 230
 231                        if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 232                                kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 233
 234                        break;
 235#ifdef CONFIG_PPC_FPU
 236                case STORE_FP:
 237                        if (kvmppc_check_fp_disabled(vcpu))
 238                                return EMULATE_DONE;
 239
 240                        /* The FP registers need to be flushed so that
 241                         * kvmppc_handle_store() can read actual FP vals
 242                         * from vcpu->arch.
 243                         */
 244                        if (vcpu->kvm->arch.kvm_ops->giveup_ext)
 245                                vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
 246                                                MSR_FP);
 247
 248                        if (op.type & FPCONV)
 249                                vcpu->arch.mmio_sp64_extend = 1;
 250
 251                        emulated = kvmppc_handle_store(vcpu,
 252                                        VCPU_FPR(vcpu, op.reg), size, 1);
 253
 254                        if ((op.type & UPDATE) && (emulated != EMULATE_FAIL))
 255                                kvmppc_set_gpr(vcpu, op.update_reg, op.ea);
 256
 257                        break;
 258#endif
 259#ifdef CONFIG_ALTIVEC
 260                case STORE_VMX:
 261                        if (kvmppc_check_altivec_disabled(vcpu))
 262                                return EMULATE_DONE;
 263
 264                        /* Hardware enforces alignment of VMX accesses. */
 265                        vcpu->arch.vaddr_accessed &= ~((unsigned long)size - 1);
 266                        vcpu->arch.paddr_accessed &= ~((unsigned long)size - 1);
 267
 268                        if (vcpu->kvm->arch.kvm_ops->giveup_ext)
 269                                vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
 270                                                MSR_VEC);
 271                        if (size == 16) { /* stvx */
 272                                vcpu->arch.mmio_copy_type =
 273                                                KVMPPC_VMX_COPY_DWORD;
 274                        } else if (size == 4) { /* stvewx  */
 275                                vcpu->arch.mmio_copy_type =
 276                                                KVMPPC_VMX_COPY_WORD;
 277                        } else if (size == 2) { /* stvehx  */
 278                                vcpu->arch.mmio_copy_type =
 279                                                KVMPPC_VMX_COPY_HWORD;
 280                        } else if (size == 1) { /* stvebx  */
 281                                vcpu->arch.mmio_copy_type =
 282                                                KVMPPC_VMX_COPY_BYTE;
 283                        } else
 284                                break;
 285
 286                        vcpu->arch.mmio_vmx_offset =
 287                                (vcpu->arch.vaddr_accessed & 0xf)/size;
 288
 289                        if (size == 16) {
 290                                vcpu->arch.mmio_vmx_copy_nums = 2;
 291                                emulated = kvmppc_handle_vmx_store(vcpu,
 292                                                op.reg, 8, 1);
 293                        } else {
 294                                vcpu->arch.mmio_vmx_copy_nums = 1;
 295                                emulated = kvmppc_handle_vmx_store(vcpu,
 296                                                op.reg, size, 1);
 297                        }
 298
 299                        break;
 300#endif
 301#ifdef CONFIG_VSX
 302                case STORE_VSX: {
 303                        int io_size_each;
 304
 305                        if (op.vsx_flags & VSX_CHECK_VEC) {
 306                                if (kvmppc_check_altivec_disabled(vcpu))
 307                                        return EMULATE_DONE;
 308                        } else {
 309                                if (kvmppc_check_vsx_disabled(vcpu))
 310                                        return EMULATE_DONE;
 311                        }
 312
 313                        if (vcpu->kvm->arch.kvm_ops->giveup_ext)
 314                                vcpu->kvm->arch.kvm_ops->giveup_ext(vcpu,
 315                                                MSR_VSX);
 316
 317                        if (op.vsx_flags & VSX_FPCONV)
 318                                vcpu->arch.mmio_sp64_extend = 1;
 319
 320                        if (op.element_size == 8)
 321                                vcpu->arch.mmio_copy_type =
 322                                                KVMPPC_VSX_COPY_DWORD;
 323                        else if (op.element_size == 4)
 324                                vcpu->arch.mmio_copy_type =
 325                                                KVMPPC_VSX_COPY_WORD;
 326                        else
 327                                break;
 328
 329                        if (size < op.element_size) {
 330                                /* precise conversion case, like stxsspx */
 331                                vcpu->arch.mmio_vsx_copy_nums = 1;
 332                                io_size_each = size;
 333                        } else { /* stxvw4x, stxvd2x, etc */
 334                                vcpu->arch.mmio_vsx_copy_nums =
 335                                                size/op.element_size;
 336                                io_size_each = op.element_size;
 337                        }
 338
 339                        emulated = kvmppc_handle_vsx_store(vcpu,
 340                                        op.reg, io_size_each, 1);
 341                        break;
 342                }
 343#endif
 344                case CACHEOP:
 345                        /* Do nothing. The guest is performing dcbi because
 346                         * hardware DMA is not snooped by the dcache, but
 347                         * emulated DMA either goes through the dcache as
 348                         * normal writes, or the host kernel has handled dcache
 349                         * coherence.
 350                         */
 351                        emulated = EMULATE_DONE;
 352                        break;
 353                default:
 354                        break;
 355                }
 356        }
 357
 358        if (emulated == EMULATE_FAIL) {
 359                advance = 0;
 360                kvmppc_core_queue_program(vcpu, 0);
 361        }
 362
 363        trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);
 364
 365        /* Advance past emulated instruction. */
 366        if (advance)
 367                kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
 368
 369        return emulated;
 370}
 371