/****************************************************************************** * emulate.c * * Generic x86 (32-bit and 64-bit) instruction decoder and emulator. * * Copyright (c) 2005 Keir Fraser * * Linux coding style, mod r/m decoder, segment base fixes, real-mode * privileged instructions: * * Copyright (C) 2006 Qumranet * Copyright 2010 Red Hat, Inc. and/or its affiliates. * * Avi Kivity * Yaniv Kamay * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. * * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4 */ #include #include "kvm_cache_regs.h" #include #include #include #include "x86.h" #include "tss.h" /* * Operand types */ #define OpNone 0ull #define OpImplicit 1ull /* No generic decode */ #define OpReg 2ull /* Register */ #define OpMem 3ull /* Memory */ #define OpAcc 4ull /* Accumulator: AL/AX/EAX/RAX */ #define OpDI 5ull /* ES:DI/EDI/RDI */ #define OpMem64 6ull /* Memory, 64-bit */ #define OpImmUByte 7ull /* Zero-extended 8-bit immediate */ #define OpDX 8ull /* DX register */ #define OpCL 9ull /* CL register (for shifts) */ #define OpImmByte 10ull /* 8-bit sign extended immediate */ #define OpOne 11ull /* Implied 1 */ #define OpImm 12ull /* Sign extended up to 32-bit immediate */ #define OpMem16 13ull /* Memory operand (16-bit). */ #define OpMem32 14ull /* Memory operand (32-bit). */ #define OpImmU 15ull /* Immediate operand, zero extended */ #define OpSI 16ull /* SI/ESI/RSI */ #define OpImmFAddr 17ull /* Immediate far address */ #define OpMemFAddr 18ull /* Far address in memory */ #define OpImmU16 19ull /* Immediate operand, 16 bits, zero extended */ #define OpES 20ull /* ES */ #define OpCS 21ull /* CS */ #define OpSS 22ull /* SS */ #define OpDS 23ull /* DS */ #define OpFS 24ull /* FS */ #define OpGS 25ull /* GS */ #define OpMem8 26ull /* 8-bit zero extended memory operand */ #define OpImm64 27ull /* Sign extended 16/32/64-bit immediate */ #define OpBits 5 /* Width of operand field */ #define OpMask ((1ull << OpBits) - 1) /* * Opcode effective-address decode tables. * Note that we only emulate instructions that have at least one memory * operand (excluding implicit stack references). We assume that stack * references and instruction fetches will never occur in special memory * areas that require emulation. So, for example, 'mov ,' need * not be handled. */ /* Operand sizes: 8-bit operands or specified/overridden size. */ #define ByteOp (1<<0) /* 8-bit operands. */ /* Destination operand type. */ #define DstShift 1 #define ImplicitOps (OpImplicit << DstShift) #define DstReg (OpReg << DstShift) #define DstMem (OpMem << DstShift) #define DstAcc (OpAcc << DstShift) #define DstDI (OpDI << DstShift) #define DstMem64 (OpMem64 << DstShift) #define DstImmUByte (OpImmUByte << DstShift) #define DstDX (OpDX << DstShift) #define DstMask (OpMask << DstShift) /* Source operand type. */ #define SrcShift 6 #define SrcNone (OpNone << SrcShift) #define SrcReg (OpReg << SrcShift) #define SrcMem (OpMem << SrcShift) #define SrcMem16 (OpMem16 << SrcShift) #define SrcMem32 (OpMem32 << SrcShift) #define SrcImm (OpImm << SrcShift) #define SrcImmByte (OpImmByte << SrcShift) #define SrcOne (OpOne << SrcShift) #define SrcImmUByte (OpImmUByte << SrcShift) #define SrcImmU (OpImmU << SrcShift) #define SrcSI (OpSI << SrcShift) #define SrcImmFAddr (OpImmFAddr << SrcShift) #define SrcMemFAddr (OpMemFAddr << SrcShift) #define SrcAcc (OpAcc << SrcShift) #define SrcImmU16 (OpImmU16 << SrcShift) #define SrcImm64 (OpImm64 << SrcShift) #define SrcDX (OpDX << SrcShift) #define SrcMem8 (OpMem8 << SrcShift) #define SrcMask (OpMask << SrcShift) #define BitOp (1<<11) #define MemAbs (1<<12) /* Memory operand is absolute displacement */ #define String (1<<13) /* String instruction (rep capable) */ #define Stack (1<<14) /* Stack instruction (push/pop) */ #define GroupMask (7<<15) /* Opcode uses one of the group mechanisms */ #define Group (1<<15) /* Bits 3:5 of modrm byte extend opcode */ #define GroupDual (2<<15) /* Alternate decoding of mod == 3 */ #define Prefix (3<<15) /* Instruction varies with 66/f2/f3 prefix */ #define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */ #define Escape (5<<15) /* Escape to coprocessor instruction */ #define Sse (1<<18) /* SSE Vector instruction */ /* Generic ModRM decode. */ #define ModRM (1<<19) /* Destination is only written; never read. */ #define Mov (1<<20) /* Misc flags */ #define Prot (1<<21) /* instruction generates #UD if not in prot-mode */ #define VendorSpecific (1<<22) /* Vendor specific instruction */ #define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */ #define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */ #define Undefined (1<<25) /* No Such Instruction */ #define Lock (1<<26) /* lock prefix is allowed for the instruction */ #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */ #define No64 (1<<28) #define PageTable (1 << 29) /* instruction used to write page table */ /* Source 2 operand type */ #define Src2Shift (30) #define Src2None (OpNone << Src2Shift) #define Src2CL (OpCL << Src2Shift) #define Src2ImmByte (OpImmByte << Src2Shift) #define Src2One (OpOne << Src2Shift) #define Src2Imm (OpImm << Src2Shift) #define Src2ES (OpES << Src2Shift) #define Src2CS (OpCS << Src2Shift) #define Src2SS (OpSS << Src2Shift) #define Src2DS (OpDS << Src2Shift) #define Src2FS (OpFS << Src2Shift) #define Src2GS (OpGS << Src2Shift) #define Src2Mask (OpMask << Src2Shift) #define Mmx ((u64)1 << 40) /* MMX Vector instruction */ #define Aligned ((u64)1 << 41) /* Explicitly aligned (e.g. MOVDQA) */ #define Unaligned ((u64)1 << 42) /* Explicitly unaligned (e.g. MOVDQU) */ #define Avx ((u64)1 << 43) /* Advanced Vector Extensions */ #define Fastop ((u64)1 << 44) /* Use opcode::u.fastop */ #define NoWrite ((u64)1 << 45) /* No writeback */ #define X2(x...) x, x #define X3(x...) X2(x), x #define X4(x...) X2(x), X2(x) #define X5(x...) X4(x), x #define X6(x...) X4(x), X2(x) #define X7(x...) X4(x), X3(x) #define X8(x...) X4(x), X4(x) #define X16(x...) X8(x), X8(x) #define NR_FASTOP (ilog2(sizeof(ulong)) + 1) #define FASTOP_SIZE 8 /* * fastop functions have a special calling convention: * * dst: [rdx]:rax (in/out) * src: rbx (in/out) * src2: rcx (in) * flags: rflags (in/out) * * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for * different operand sizes can be reached by calculation, rather than a jump * table (which would be bigger than the code). * * fastop functions are declared as taking a never-defined fastop parameter, * so they can't be called from C directly. */ struct fastop; struct opcode { u64 flags : 56; u64 intercept : 8; union { int (*execute)(struct x86_emulate_ctxt *ctxt); const struct opcode *group; const struct group_dual *gdual; const struct gprefix *gprefix; const struct escape *esc; void (*fastop)(struct fastop *fake); } u; int (*check_perm)(struct x86_emulate_ctxt *ctxt); }; struct group_dual { struct opcode mod012[8]; struct opcode mod3[8]; }; struct gprefix { struct opcode pfx_no; struct opcode pfx_66; struct opcode pfx_f2; struct opcode pfx_f3; }; struct escape { struct opcode op[8]; struct opcode high[64]; }; /* EFLAGS bit definitions. */ #define EFLG_ID (1<<21) #define EFLG_VIP (1<<20) #define EFLG_VIF (1<<19) #define EFLG_AC (1<<18) #define EFLG_VM (1<<17) #define EFLG_RF (1<<16) #define EFLG_IOPL (3<<12) #define EFLG_NT (1<<14) #define EFLG_OF (1<<11) #define EFLG_DF (1<<10) #define EFLG_IF (1<<9) #define EFLG_TF (1<<8) #define EFLG_SF (1<<7) #define EFLG_ZF (1<<6) #define EFLG_AF (1<<4) #define EFLG_PF (1<<2) #define EFLG_CF (1<<0) #define EFLG_RESERVED_ZEROS_MASK 0xffc0802a #define EFLG_RESERVED_ONE_MASK 2 static ulong reg_read(struct x86_emulate_ctxt *ctxt, unsigned nr) { if (!(ctxt->regs_valid & (1 << nr))) { ctxt->regs_valid |= 1 << nr; ctxt->_regs[nr] = ctxt->ops->read_gpr(ctxt, nr); } return ctxt->_regs[nr]; } static ulong *reg_write(struct x86_emulate_ctxt *ctxt, unsigned nr) { ctxt->regs_valid |= 1 << nr; ctxt->regs_dirty |= 1 << nr; return &ctxt->_regs[nr]; } static ulong *reg_rmw(struct x86_emulate_ctxt *ctxt, unsigned nr) { reg_read(ctxt, nr); return reg_write(ctxt, nr); } static void writeback_registers(struct x86_emulate_ctxt *ctxt) { unsigned reg; for_each_set_bit(reg, (ulong *)&ctxt->regs_dirty, 16) ctxt->ops->write_gpr(ctxt, reg, ctxt->_regs[reg]); } static void invalidate_registers(struct x86_emulate_ctxt *ctxt) { ctxt->regs_dirty = 0; ctxt->regs_valid = 0; } /* * Instruction emulation: * Most instructions are emulated directly via a fragment of inline assembly * code. This allows us to save/restore EFLAGS and thus very easily pick up * any modified flags. */ #if defined(CONFIG_X86_64) #define _LO32 "k" /* force 32-bit operand */ #define _STK "%%rsp" /* stack pointer */ #elif defined(__i386__) #define _LO32 "" /* force 32-bit operand */ #define _STK "%%esp" /* stack pointer */ #endif /* * These EFLAGS bits are restored from saved value during emulation, and * any changes are written back to the saved value after emulation. */ #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF) /* Before executing instruction: restore necessary bits in EFLAGS. */ #define _PRE_EFLAGS(_sav, _msk, _tmp) \ /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); _sav &= ~_msk; */ \ "movl %"_sav",%"_LO32 _tmp"; " \ "push %"_tmp"; " \ "push %"_tmp"; " \ "movl %"_msk",%"_LO32 _tmp"; " \ "andl %"_LO32 _tmp",("_STK"); " \ "pushf; " \ "notl %"_LO32 _tmp"; " \ "andl %"_LO32 _tmp",("_STK"); " \ "andl %"_LO32 _tmp","__stringify(BITS_PER_LONG/4)"("_STK"); " \ "pop %"_tmp"; " \ "orl %"_LO32 _tmp",("_STK"); " \ "popf; " \ "pop %"_sav"; " /* After executing instruction: write-back necessary bits in EFLAGS. */ #define _POST_EFLAGS(_sav, _msk, _tmp) \ /* _sav |= EFLAGS & _msk; */ \ "pushf; " \ "pop %"_tmp"; " \ "andl %"_msk",%"_LO32 _tmp"; " \ "orl %"_LO32 _tmp",%"_sav"; " #ifdef CONFIG_X86_64 #define ON64(x) x #else #define ON64(x) #endif #define ____emulate_2op(ctxt, _op, _x, _y, _suffix, _dsttype) \ do { \ __asm__ __volatile__ ( \ _PRE_EFLAGS("0", "4", "2") \ _op _suffix " %"_x"3,%1; " \ _POST_EFLAGS("0", "4", "2") \ : "=m" ((ctxt)->eflags), \ "+q" (*(_dsttype*)&(ctxt)->dst.val), \ "=&r" (_tmp) \ : _y ((ctxt)->src.val), "i" (EFLAGS_MASK)); \ } while (0) /* Raw emulation: instruction has two explicit operands. */ #define __emulate_2op_nobyte(ctxt,_op,_wx,_wy,_lx,_ly,_qx,_qy) \ do { \ unsigned long _tmp; \ \ switch ((ctxt)->dst.bytes) { \ case 2: \ ____emulate_2op(ctxt,_op,_wx,_wy,"w",u16); \ break; \ case 4: \ ____emulate_2op(ctxt,_op,_lx,_ly,"l",u32); \ break; \ case 8: \ ON64(____emulate_2op(ctxt,_op,_qx,_qy,"q",u64)); \ break; \ } \ } while (0) #define __emulate_2op(ctxt,_op,_bx,_by,_wx,_wy,_lx,_ly,_qx,_qy) \ do { \ unsigned long _tmp; \ switch ((ctxt)->dst.bytes) { \ case 1: \ ____emulate_2op(ctxt,_op,_bx,_by,"b",u8); \ break; \ default: \ __emulate_2op_nobyte(ctxt, _op, \ _wx, _wy, _lx, _ly, _qx, _qy); \ break; \ } \ } while (0) /* Source operand is byte-sized and may be restricted to just %cl. */ #define emulate_2op_SrcB(ctxt, _op) \ __emulate_2op(ctxt, _op, "b", "c", "b", "c", "b", "c", "b", "c") /* Source operand is byte, word, long or quad sized. */ #define emulate_2op_SrcV(ctxt, _op) \ __emulate_2op(ctxt, _op, "b", "q", "w", "r", _LO32, "r", "", "r") /* Source operand is word, long or quad sized. */ #define emulate_2op_SrcV_nobyte(ctxt, _op) \ __emulate_2op_nobyte(ctxt, _op, "w", "r", _LO32, "r", "", "r") /* Instruction has three operands and one operand is stored in ECX register */ #define __emulate_2op_cl(ctxt, _op, _suffix, _type) \ do { \ unsigned long _tmp; \ _type _clv = (ctxt)->src2.val; \ _type _srcv = (ctxt)->src.val; \ _type _dstv = (ctxt)->dst.val; \ \ __asm__ __volatile__ ( \ _PRE_EFLAGS("0", "5", "2") \ _op _suffix " %4,%1 \n" \ _POST_EFLAGS("0", "5", "2") \ : "=m" ((ctxt)->eflags), "+r" (_dstv), "=&r" (_tmp) \ : "c" (_clv) , "r" (_srcv), "i" (EFLAGS_MASK) \ ); \ \ (ctxt)->src2.val = (unsigned long) _clv; \ (ctxt)->src2.val = (unsigned long) _srcv; \ (ctxt)->dst.val = (unsigned long) _dstv; \ } while (0) #define emulate_2op_cl(ctxt, _op) \ do { \ switch ((ctxt)->dst.bytes) { \ case 2: \ __emulate_2op_cl(ctxt, _op, "w", u16); \ break; \ case 4: \ __emulate_2op_cl(ctxt, _op, "l", u32); \ break; \ case 8: \ ON64(__emulate_2op_cl(ctxt, _op, "q", ulong)); \ break; \ } \ } while (0) #define __emulate_1op(ctxt, _op, _suffix) \ do { \ unsigned long _tmp; \ \ __asm__ __volatile__ ( \ _PRE_EFLAGS("0", "3", "2") \ _op _suffix " %1; " \ _POST_EFLAGS("0", "3", "2") \ : "=m" ((ctxt)->eflags), "+m" ((ctxt)->dst.val), \ "=&r" (_tmp) \ : "i" (EFLAGS_MASK)); \ } while (0) /* Instruction has only one explicit operand (no source operand). */ #define emulate_1op(ctxt, _op) \ do { \ switch ((ctxt)->dst.bytes) { \ case 1: __emulate_1op(ctxt, _op, "b"); break; \ case 2: __emulate_1op(ctxt, _op, "w"); break; \ case 4: __emulate_1op(ctxt, _op, "l"); break; \ case 8: ON64(__emulate_1op(ctxt, _op, "q")); break; \ } \ } while (0) #define FOP_ALIGN ".align " __stringify(FASTOP_SIZE) " \n\t" #define FOP_RET "ret \n\t" #define FOP_START(op) \ extern void em_##op(struct fastop *fake); \ asm(".pushsection .text, \"ax\" \n\t" \ ".global em_" #op " \n\t" \ FOP_ALIGN \ "em_" #op ": \n\t" #define FOP_END \ ".popsection") #define FOP1E(op, dst) \ FOP_ALIGN #op " %" #dst " \n\t" FOP_RET #define FASTOP1(op) \ FOP_START(op) \ FOP1E(op##b, al) \ FOP1E(op##w, ax) \ FOP1E(op##l, eax) \ ON64(FOP1E(op##q, rax)) \ FOP_END #define __emulate_1op_rax_rdx(ctxt, _op, _suffix, _ex) \ do { \ unsigned long _tmp; \ ulong *rax = reg_rmw((ctxt), VCPU_REGS_RAX); \ ulong *rdx = reg_rmw((ctxt), VCPU_REGS_RDX); \ \ __asm__ __volatile__ ( \ _PRE_EFLAGS("0", "5", "1") \ "1: \n\t" \ _op _suffix " %6; " \ "2: \n\t" \ _POST_EFLAGS("0", "5", "1") \ ".pushsection .fixup,\"ax\" \n\t" \ "3: movb $1, %4 \n\t" \ "jmp 2b \n\t" \ ".popsection \n\t" \ _ASM_EXTABLE(1b, 3b) \ : "=m" ((ctxt)->eflags), "=&r" (_tmp), \ "+a" (*rax), "+d" (*rdx), "+qm"(_ex) \ : "i" (EFLAGS_MASK), "m" ((ctxt)->src.val)); \ } while (0) /* instruction has only one source operand, destination is implicit (e.g. mul, div, imul, idiv) */ #define emulate_1op_rax_rdx(ctxt, _op, _ex) \ do { \ switch((ctxt)->src.bytes) { \ case 1: \ __emulate_1op_rax_rdx(ctxt, _op, "b", _ex); \ break; \ case 2: \ __emulate_1op_rax_rdx(ctxt, _op, "w", _ex); \ break; \ case 4: \ __emulate_1op_rax_rdx(ctxt, _op, "l", _ex); \ break; \ case 8: ON64( \ __emulate_1op_rax_rdx(ctxt, _op, "q", _ex)); \ break; \ } \ } while (0) static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt, enum x86_intercept intercept, enum x86_intercept_stage stage) { struct x86_instruction_info info = { .intercept = intercept, .rep_prefix = ctxt->rep_prefix, .modrm_mod = ctxt->modrm_mod, .modrm_reg = ctxt->modrm_reg, .modrm_rm = ctxt->modrm_rm, .src_val = ctxt->src.val64, .src_bytes = ctxt->src.bytes, .dst_bytes = ctxt->dst.bytes, .ad_bytes = ctxt->ad_bytes, .next_rip = ctxt->eip, }; return ctxt->ops->intercept(ctxt, &info, stage); } static void assign_masked(ulong *dest, ulong src, ulong mask) { *dest = (*dest & ~mask) | (src & mask); } static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt) { return (1UL << (ctxt->ad_bytes << 3)) - 1; } static ulong stack_mask(struct x86_emulate_ctxt *ctxt) { u16 sel; struct desc_struct ss; if (ctxt->mode == X86EMUL_MODE_PROT64) return ~0UL; ctxt->ops->get_segment(ctxt, &sel, &ss, NULL, VCPU_SREG_SS); return ~0U >> ((ss.d ^ 1) * 16); /* d=0: 0xffff; d=1: 0xffffffff */ } static int stack_size(struct x86_emulate_ctxt *ctxt) { return (__fls(stack_mask(ctxt)) + 1) >> 3; } /* Access/update address held in a register, based on addressing mode. */ static inline unsigned long address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg) { if (ctxt->ad_bytes == sizeof(unsigned long)) return reg; else return reg & ad_mask(ctxt); } static inline unsigned long register_address(struct x86_emulate_ctxt *ctxt, unsigned long reg) { return address_mask(ctxt, reg); } static void masked_increment(ulong *reg, ulong mask, int inc) { assign_masked(reg, *reg + inc, mask); } static inline void register_address_increment(struct x86_emulate_ctxt *ctxt, unsigned long *reg, int inc) { ulong mask; if (ctxt->ad_bytes == sizeof(unsigned long)) mask = ~0UL; else mask = ad_mask(ctxt); masked_increment(reg, mask, inc); } static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc) { masked_increment(reg_rmw(ctxt, VCPU_REGS_RSP), stack_mask(ctxt), inc); } static inline void jmp_rel(struct x86_emulate_ctxt *ctxt, int rel) { register_address_increment(ctxt, &ctxt->_eip, rel); } static u32 desc_limit_scaled(struct desc_struct *desc) { u32 limit = get_desc_limit(desc); return desc->g ? (limit << 12) | 0xfff : limit; } static void set_seg_override(struct x86_emulate_ctxt *ctxt, int seg) { ctxt->has_seg_override = true; ctxt->seg_override = seg; } static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg) { if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS) return 0; return ctxt->ops->get_cached_segment_base(ctxt, seg); } static unsigned seg_override(struct x86_emulate_ctxt *ctxt) { if (!ctxt->has_seg_override) return 0; return ctxt->seg_override; } static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, u32 error, bool valid) { ctxt->exception.vector = vec; ctxt->exception.error_code = error; ctxt->exception.error_code_valid = valid; return X86EMUL_PROPAGATE_FAULT; } static int emulate_db(struct x86_emulate_ctxt *ctxt) { return emulate_exception(ctxt, DB_VECTOR, 0, false); } static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err) { return emulate_exception(ctxt, GP_VECTOR, err, true); } static int emulate_ss(struct x86_emulate_ctxt *ctxt, int err) { return emulate_exception(ctxt, SS_VECTOR, err, true); } static int emulate_ud(struct x86_emulate_ctxt *ctxt) { return emulate_exception(ctxt, UD_VECTOR, 0, false); } static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err) { return emulate_exception(ctxt, TS_VECTOR, err, true); } static int emulate_de(struct x86_emulate_ctxt *ctxt) { return emulate_exception(ctxt, DE_VECTOR, 0, false); } static int emulate_nm(struct x86_emulate_ctxt *ctxt) { return emulate_exception(ctxt, NM_VECTOR, 0, false); } static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg) { u16 selector; struct desc_struct desc; ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg); return selector; } static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector, unsigned seg) { u16 dummy; u32 base3; struct desc_struct desc; ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg); ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg); } /* * x86 defines three classes of vector instructions: explicitly * aligned, explicitly unaligned, and the rest, which change behaviour * depending on whether they're AVX encoded or not. * * Also included is CMPXCHG16B which is not a vector instruction, yet it is * subject to the same check. */ static bool insn_aligned(struct x86_emulate_ctxt *ctxt, unsigned size) { if (likely(size < 16)) return false; if (ctxt->d & Aligned) return true; else if (ctxt->d & Unaligned) return false; else if (ctxt->d & Avx) return false; else return true; } static int __linearize(struct x86_emulate_ctxt *ctxt, struct segmented_address addr, unsigned size, bool write, bool fetch, ulong *linear) { struct desc_struct desc; bool usable; ulong la; u32 lim; u16 sel; unsigned cpl; la = seg_base(ctxt, addr.seg) + addr.ea; switch (ctxt->mode) { case X86EMUL_MODE_PROT64: if (((signed long)la << 16) >> 16 != la) return emulate_gp(ctxt, 0); break; default: usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL, addr.seg); if (!usable) goto bad; /* code segment in protected mode or read-only data segment */ if ((((ctxt->mode != X86EMUL_MODE_REAL) && (desc.type & 8)) || !(desc.type & 2)) && write) goto bad; /* unreadable code segment */ if (!fetch && (desc.type & 8) && !(desc.type & 2)) goto bad; lim = desc_limit_scaled(&desc); if ((desc.type & 8) || !(desc.type & 4)) { /* expand-up segment */ if (addr.ea > lim || (u32)(addr.ea + size - 1) > lim) goto bad; } else { /* expand-down segment */ if (addr.ea <= lim || (u32)(addr.ea + size - 1) <= lim) goto bad; lim = desc.d ? 0xffffffff : 0xffff; if (addr.ea > lim || (u32)(addr.ea + size - 1) > lim) goto bad; } cpl = ctxt->ops->cpl(ctxt); if (!(desc.type & 8)) { /* data segment */ if (cpl > desc.dpl) goto bad; } else if ((desc.type & 8) && !(desc.type & 4)) { /* nonconforming code segment */ if (cpl != desc.dpl) goto bad; } else if ((desc.type & 8) && (desc.type & 4)) { /* conforming code segment */ if (cpl < desc.dpl) goto bad; } break; } if (fetch ? ctxt->mode != X86EMUL_MODE_PROT64 : ctxt->ad_bytes != 8) la &= (u32)-1; if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0)) return emulate_gp(ctxt, 0); *linear = la; return X86EMUL_CONTINUE; bad: if (addr.seg == VCPU_SREG_SS) return emulate_ss(ctxt, sel); else return emulate_gp(ctxt, sel); } static int linearize(struct x86_emulate_ctxt *ctxt, struct segmented_address addr, unsigned size, bool write, ulong *linear) { return __linearize(ctxt, addr, size, write, false, linear); } static int segmented_read_std(struct x86_emulate_ctxt *ctxt, struct segmented_address addr, void *data, unsigned size) { int rc; ulong linear; rc = linearize(ctxt, addr, size, false, &linear); if (rc != X86EMUL_CONTINUE) return rc; return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception); } /* * Fetch the next byte of the instruction being emulated which is pointed to * by ctxt->_eip, then increment ctxt->_eip. * * Also prefetch the remaining bytes of the instruction without crossing page * boundary if they are not in fetch_cache yet. */ static int do_insn_fetch_byte(struct x86_emulate_ctxt *ctxt, u8 *dest) { struct fetch_cache *fc = &ctxt->fetch; int rc; int size, cur_size; if (ctxt->_eip == fc->end) { unsigned long linear; struct segmented_address addr = { .seg = VCPU_SREG_CS, .ea = ctxt->_eip }; cur_size = fc->end - fc->start; size = min(15UL - cur_size, PAGE_SIZE - offset_in_page(ctxt->_eip)); rc = __linearize(ctxt, addr, size, false, true, &linear); if (unlikely(rc != X86EMUL_CONTINUE)) return rc; rc = ctxt->ops->fetch(ctxt, linear, fc->data + cur_size, size, &ctxt->exception); if (unlikely(rc != X86EMUL_CONTINUE)) return rc; fc->end += size; } *dest = fc->data[ctxt->_eip - fc->start]; ctxt->_eip++; return X86EMUL_CONTINUE; } static int do_insn_fetch(struct x86_emulate_ctxt *ctxt, void *dest, unsigned size) { int rc; /* x86 instructions are limited to 15 bytes. */ if (unlikely(ctxt->_eip + size - ctxt->eip > 15)) return X86EMUL_UNHANDLEABLE; while (size--) { rc = do_insn_fetch_byte(ctxt, dest++); if (rc != X86EMUL_CONTINUE) return rc; } return X86EMUL_CONTINUE; } /* Fetch next part of the instruction being emulated. */ #define insn_fetch(_type, _ctxt) \ ({ unsigned long _x; \ rc = do_insn_fetch(_ctxt, &_x, sizeof(_type)); \ if (rc != X86EMUL_CONTINUE) \ goto done; \ (_type)_x; \ }) #define insn_fetch_arr(_arr, _size, _ctxt) \ ({ rc = do_insn_fetch(_ctxt, _arr, (_size)); \ if (rc != X86EMUL_CONTINUE) \ goto done; \ }) /* * Given the 'reg' portion of a ModRM byte, and a register block, return a * pointer into the block that addresses the relevant register. * @highbyte_regs specifies whether to decode AH,CH,DH,BH. */ static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg, int highbyte_regs) { void *p; if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8) p = (unsigned char *)reg_rmw(ctxt, modrm_reg & 3) + 1; else p = reg_rmw(ctxt, modrm_reg); return p; } static int read_descriptor(struct x86_emulate_ctxt *ctxt, struct segmented_address addr, u16 *size, unsigned long *address, int op_bytes) { int rc; if (op_bytes == 2) op_bytes = 3; *address = 0; rc = segmented_read_std(ctxt, addr, size, 2); if (rc != X86EMUL_CONTINUE) return rc; addr.ea += 2; rc = segmented_read_std(ctxt, addr, address, op_bytes); return rc; } static int test_cc(unsigned int condition, unsigned int flags) { int rc = 0; switch ((condition & 15) >> 1) { case 0: /* o */ rc |= (flags & EFLG_OF); break; case 1: /* b/c/nae */ rc |= (flags & EFLG_CF); break; case 2: /* z/e */ rc |= (flags & EFLG_ZF); break; case 3: /* be/na */ rc |= (flags & (EFLG_CF|EFLG_ZF)); break; case 4: /* s */ rc |= (flags & EFLG_SF); break; case 5: /* p/pe */ rc |= (flags & EFLG_PF); break; case 7: /* le/ng */ rc |= (flags & EFLG_ZF); /* fall through */ case 6: /* l/nge */ rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF)); break; } /* Odd condition identifiers (lsb == 1) have inverted sense. */ return (!!rc ^ (condition & 1)); } static void fetch_register_operand(struct operand *op) { switch (op->bytes) { case 1: op->val = *(u8 *)op->addr.reg; break; case 2: op->val = *(u16 *)op->addr.reg; break; case 4: op->val = *(u32 *)op->addr.reg; break; case 8: op->val = *(u64 *)op->addr.reg; break; } } static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg) { ctxt->ops->get_fpu(ctxt); switch (reg) { case 0: asm("movdqa %%xmm0, %0" : "=m"(*data)); break; case 1: asm("movdqa %%xmm1, %0" : "=m"(*data)); break; case 2: asm("movdqa %%xmm2, %0" : "=m"(*data)); break; case 3: asm("movdqa %%xmm3, %0" : "=m"(*data)); break; case 4: asm("movdqa %%xmm4, %0" : "=m"(*data)); break; case 5: asm("movdqa %%xmm5, %0" : "=m"(*data)); break; case 6: asm("movdqa %%xmm6, %0" : "=m"(*data)); break; case 7: asm("movdqa %%xmm7, %0" : "=m"(*data)); break; #ifdef CONFIG_X86_64 case 8: asm("movdqa %%xmm8, %0" : "=m"(*data)); break; case 9: asm("movdqa %%xmm9, %0" : "=m"(*data)); break; case 10: asm("movdqa %%xmm10, %0" : "=m"(*data)); break; case 11: asm("movdqa %%xmm11, %0" : "=m"(*data)); break; case 12: asm("movdqa %%xmm12, %0" : "=m"(*data)); break; case 13: asm("movdqa %%xmm13, %0" : "=m"(*data)); break; case 14: asm("movdqa %%xmm14, %0" : "=m"(*data)); break; case 15: asm("movdqa %%xmm15, %0" : "=m"(*data)); break; #endif default: BUG(); } ctxt->ops->put_fpu(ctxt); } static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg) { ctxt->ops->get_fpu(ctxt); switch (reg) { case 0: asm("movdqa %0, %%xmm0" : : "m"(*data)); break; case 1: asm("movdqa %0, %%xmm1" : : "m"(*data)); break; case 2: asm("movdqa %0, %%xmm2" : : "m"(*data)); break; case 3: asm("movdqa %0, %%xmm3" : : "m"(*data)); break; case 4: asm("movdqa %0, %%xmm4" : : "m"(*data)); break; case 5: asm("movdqa %0, %%xmm5" : : "m"(*data)); break; case 6: asm("movdqa %0, %%xmm6" : : "m"(*data)); break; case 7: asm("movdqa %0, %%xmm7" : : "m"(*data)); break; #ifdef CONFIG_X86_64 case 8: asm("movdqa %0, %%xmm8" : : "m"(*data)); break; case 9: asm("movdqa %0, %%xmm9" : : "m"(*data)); break; case 10: asm("movdqa %0, %%xmm10" : : "m"(*data)); break; case 11: asm("movdqa %0, %%xmm11" : : "m"(*data)); break; case 12: asm("movdqa %0, %%xmm12" : : "m"(*data)); break; case 13: asm("movdqa %0, %%xmm13" : : "m"(*data)); break; case 14: asm("movdqa %0, %%xmm14" : : "m"(*data)); break; case 15: asm("movdqa %0, %%xmm15" : : "m"(*data)); break; #endif default: BUG(); } ctxt->ops->put_fpu(ctxt); } static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg) { ctxt->ops->get_fpu(ctxt); switch (reg) { case 0: asm("movq %%mm0, %0" : "=m"(*data)); break; case 1: asm("movq %%mm1, %0" : "=m"(*data)); break; case 2: asm("movq %%mm2, %0" : "=m"(*data)); break; case 3: asm("movq %%mm3, %0" : "=m"(*data)); break; case 4: asm("movq %%mm4, %0" : "=m"(*data)); break; case 5: asm("movq %%mm5, %0" : "=m"(*data)); break; case 6: asm("movq %%mm6, %0" : "=m"(*data)); break; case 7: asm("movq %%mm7, %0" : "=m"(*data)); break; default: BUG(); } ctxt->ops->put_fpu(ctxt); } static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg) { ctxt->ops->get_fpu(ctxt); switch (reg) { case 0: asm("movq %0, %%mm0" : : "m"(*data)); break; case 1: asm("movq %0, %%mm1" : : "m"(*data)); break; case 2: asm("movq %0, %%mm2" : : "m"(*data)); break; case 3: asm("movq %0, %%mm3" : : "m"(*data)); break; case 4: asm("movq %0, %%mm4" : : "m"(*data)); break; case 5: asm("movq %0, %%mm5" : : "m"(*data)); break; case 6: asm("movq %0, %%mm6" : : "m"(*data)); break; case 7: asm("movq %0, %%mm7" : : "m"(*data)); break; default: BUG(); } ctxt->ops->put_fpu(ctxt); } static int em_fninit(struct x86_emulate_ctxt *ctxt) { if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) return emulate_nm(ctxt); ctxt->ops->get_fpu(ctxt); asm volatile("fninit"); ctxt->ops->put_fpu(ctxt); return X86EMUL_CONTINUE; } static int em_fnstcw(struct x86_emulate_ctxt *ctxt) { u16 fcw; if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) return emulate_nm(ctxt); ctxt->ops->get_fpu(ctxt); asm volatile("fnstcw %0": "+m"(fcw)); ctxt->ops->put_fpu(ctxt); /* force 2 byte destination */ ctxt->dst.bytes = 2; ctxt->dst.val = fcw; return X86EMUL_CONTINUE; } static int em_fnstsw(struct x86_emulate_ctxt *ctxt) { u16 fsw; if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) return emulate_nm(ctxt); ctxt->ops->get_fpu(ctxt); asm volatile("fnstsw %0": "+m"(fsw)); ctxt->ops->put_fpu(ctxt); /* force 2 byte destination */ ctxt->dst.bytes = 2; ctxt->dst.val = fsw; return X86EMUL_CONTINUE; } static void decode_register_operand(struct x86_emulate_ctxt *ctxt, struct operand *op) { unsigned reg = ctxt->modrm_reg; int highbyte_regs = ctxt->rex_prefix == 0; if (!(ctxt->d & ModRM)) reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3); if (ctxt->d & Sse) { op->type = OP_XMM; op->bytes = 16; op->addr.xmm = reg; read_sse_reg(ctxt, &op->vec_val, reg); return; } if (ctxt->d & Mmx) { reg &= 7; op->type = OP_MM; op->bytes = 8; op->addr.mm = reg; return; } op->type = OP_REG; if (ctxt->d & ByteOp) { op->addr.reg = decode_register(ctxt, reg, highbyte_regs); op->bytes = 1; } else { op->addr.reg = decode_register(ctxt, reg, 0); op->bytes = ctxt->op_bytes; } fetch_register_operand(op); op->orig_val = op->val; } static void adjust_modrm_seg(struct x86_emulate_ctxt *ctxt, int base_reg) { if (base_reg == VCPU_REGS_RSP || base_reg == VCPU_REGS_RBP) ctxt->modrm_seg = VCPU_SREG_SS; } static int decode_modrm(struct x86_emulate_ctxt *ctxt, struct operand *op) { u8 sib; int index_reg = 0, base_reg = 0, scale; int rc = X86EMUL_CONTINUE; ulong modrm_ea = 0; if (ctxt->rex_prefix) { ctxt->modrm_reg = (ctxt->rex_prefix & 4) << 1; /* REX.R */ index_reg = (ctxt->rex_prefix & 2) << 2; /* REX.X */ ctxt->modrm_rm = base_reg = (ctxt->rex_prefix & 1) << 3; /* REG.B */ } ctxt->modrm_mod |= (ctxt->modrm & 0xc0) >> 6; ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3; ctxt->modrm_rm |= (ctxt->modrm & 0x07); ctxt->modrm_seg = VCPU_SREG_DS; if (ctxt->modrm_mod == 3) { op->type = OP_REG; op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; op->addr.reg = decode_register(ctxt, ctxt->modrm_rm, ctxt->d & ByteOp); if (ctxt->d & Sse) { op->type = OP_XMM; op->bytes = 16; op->addr.xmm = ctxt->modrm_rm; read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm); return rc; } if (ctxt->d & Mmx) { op->type = OP_MM; op->bytes = 8; op->addr.xmm = ctxt->modrm_rm & 7; return rc; } fetch_register_operand(op); return rc; } op->type = OP_MEM; if (ctxt->ad_bytes == 2) { unsigned bx = reg_read(ctxt, VCPU_REGS_RBX); unsigned bp = reg_read(ctxt, VCPU_REGS_RBP); unsigned si = reg_read(ctxt, VCPU_REGS_RSI); unsigned di = reg_read(ctxt, VCPU_REGS_RDI); /* 16-bit ModR/M decode. */ switch (ctxt->modrm_mod) { case 0: if (ctxt->modrm_rm == 6) modrm_ea += insn_fetch(u16, ctxt); break; case 1: modrm_ea += insn_fetch(s8, ctxt); break; case 2: modrm_ea += insn_fetch(u16, ctxt); break; } switch (ctxt->modrm_rm) { case 0: modrm_ea += bx + si; break; case 1: modrm_ea += bx + di; break; case 2: modrm_ea += bp + si; break; case 3: modrm_ea += bp + di; break; case 4: modrm_ea += si; break; case 5: modrm_ea += di; break; case 6: if (ctxt->modrm_mod != 0) modrm_ea += bp; break; case 7: modrm_ea += bx; break; } if (ctxt->modrm_rm == 2 || ctxt->modrm_rm == 3 || (ctxt->modrm_rm == 6 && ctxt->modrm_mod != 0)) ctxt->modrm_seg = VCPU_SREG_SS; modrm_ea = (u16)modrm_ea; } else { /* 32/64-bit ModR/M decode. */ if ((ctxt->modrm_rm & 7) == 4) { sib = insn_fetch(u8, ctxt); index_reg |= (sib >> 3) & 7; base_reg |= sib & 7; scale = sib >> 6; if ((base_reg & 7) == 5 && ctxt->modrm_mod == 0) modrm_ea += insn_fetch(s32, ctxt); else { modrm_ea += reg_read(ctxt, base_reg); adjust_modrm_seg(ctxt, base_reg); } if (index_reg != 4) modrm_ea += reg_read(ctxt, index_reg) << scale; } else if ((ctxt->modrm_rm & 7) == 5 && ctxt->modrm_mod == 0) { if (ctxt->mode == X86EMUL_MODE_PROT64) ctxt->rip_relative = 1; } else { base_reg = ctxt->modrm_rm; modrm_ea += reg_read(ctxt, base_reg); adjust_modrm_seg(ctxt, base_reg); } switch (ctxt->modrm_mod) { case 0: if (ctxt->modrm_rm == 5) modrm_ea += insn_fetch(s32, ctxt); break; case 1: modrm_ea += insn_fetch(s8, ctxt); break; case 2: modrm_ea += insn_fetch(s32, ctxt); break; } } op->addr.mem.ea = modrm_ea; done: return rc; } static int decode_abs(struct x86_emulate_ctxt *ctxt, struct operand *op) { int rc = X86EMUL_CONTINUE; op->type = OP_MEM; switch (ctxt->ad_bytes) { case 2: op->addr.mem.ea = insn_fetch(u16, ctxt); break; case 4: op->addr.mem.ea = insn_fetch(u32, ctxt); break; case 8: op->addr.mem.ea = insn_fetch(u64, ctxt); break; } done: return rc; } static void fetch_bit_operand(struct x86_emulate_ctxt *ctxt) { long sv = 0, mask; if (ctxt->dst.type == OP_MEM && ctxt->src.type == OP_REG) { mask = ~(ctxt->dst.bytes * 8 - 1); if (ctxt->src.bytes == 2) sv = (s16)ctxt->src.val & (s16)mask; else if (ctxt->src.bytes == 4) sv = (s32)ctxt->src.val & (s32)mask; ctxt->dst.addr.mem.ea += (sv >> 3); } /* only subword offset */ ctxt->src.val &= (ctxt->dst.bytes << 3) - 1; } static int read_emulated(struct x86_emulate_ctxt *ctxt, unsigned long addr, void *dest, unsigned size) { int rc; struct read_cache *mc = &ctxt->mem_read; if (mc->pos < mc->end) goto read_cached; WARN_ON((mc->end + size) >= sizeof(mc->data)); rc = ctxt->ops->read_emulated(ctxt, addr, mc->data + mc->end, size, &ctxt->exception); if (rc != X86EMUL_CONTINUE) return rc; mc->end += size; read_cached: memcpy(dest, mc->data + mc->pos, size); mc->pos += size; return X86EMUL_CONTINUE; } static int segmented_read(struct x86_emulate_ctxt *ctxt, struct segmented_address addr, void *data, unsigned size) { int rc; ulong linear; rc = linearize(ctxt, addr, size, false, &linear); if (rc != X86EMUL_CONTINUE) return rc; return read_emulated(ctxt, linear, data, size); } static int segmented_write(struct x86_emulate_ctxt *ctxt, struct segmented_address addr, const void *data, unsigned size) { int rc; ulong linear; rc = linearize(ctxt, addr, size, true, &linear); if (rc != X86EMUL_CONTINUE) return rc; return ctxt->ops->write_emulated(ctxt, linear, data, size, &ctxt->exception); } static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt, struct segmented_address addr, const void *orig_data, const void *data, unsigned size) { int rc; ulong linear; rc = linearize(ctxt, addr, size, true, &linear); if (rc != X86EMUL_CONTINUE) return rc; return ctxt->ops->cmpxchg_emulated(ctxt, linear, orig_data, data, size, &ctxt->exception); } static int pio_in_emulated(struct x86_emulate_ctxt *ctxt, unsigned int size, unsigned short port, void *dest) { struct read_cache *rc = &ctxt->io_read; if (rc->pos == rc->end) { /* refill pio read ahead */ unsigned int in_page, n; unsigned int count = ctxt->rep_prefix ? address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) : 1; in_page = (ctxt->eflags & EFLG_DF) ? offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)) : PAGE_SIZE - offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)); n = min(min(in_page, (unsigned int)sizeof(rc->data)) / size, count); if (n == 0) n = 1; rc->pos = rc->end = 0; if (!ctxt->ops->pio_in_emulated(ctxt, size, port, rc->data, n)) return 0; rc->end = n * size; } if (ctxt->rep_prefix && !(ctxt->eflags & EFLG_DF)) { ctxt->dst.data = rc->data + rc->pos; ctxt->dst.type = OP_MEM_STR; ctxt->dst.count = (rc->end - rc->pos) / size; rc->pos = rc->end; } else { memcpy(dest, rc->data + rc->pos, size); rc->pos += size; } return 1; } static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt, u16 index, struct desc_struct *desc) { struct desc_ptr dt; ulong addr; ctxt->ops->get_idt(ctxt, &dt); if (dt.size < index * 8 + 7) return emulate_gp(ctxt, index << 3 | 0x2); addr = dt.address + index * 8; return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc, &ctxt->exception); } static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, u16 selector, struct desc_ptr *dt) { const struct x86_emulate_ops *ops = ctxt->ops; if (selector & 1 << 2) { struct desc_struct desc; u16 sel; memset (dt, 0, sizeof *dt); if (!ops->get_segment(ctxt, &sel, &desc, NULL, VCPU_SREG_LDTR)) return; dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */ dt->address = get_desc_base(&desc); } else ops->get_gdt(ctxt, dt); } /* allowed just for 8 bytes segments */ static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, u16 selector, struct desc_struct *desc, ulong *desc_addr_p) { struct desc_ptr dt; u16 index = selector >> 3; ulong addr; get_descriptor_table_ptr(ctxt, selector, &dt); if (dt.size < index * 8 + 7) return emulate_gp(ctxt, selector & 0xfffc); *desc_addr_p = addr = dt.address + index * 8; return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc, &ctxt->exception); } /* allowed just for 8 bytes segments */ static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, u16 selector, struct desc_struct *desc) { struct desc_ptr dt; u16 index = selector >> 3; ulong addr; get_descriptor_table_ptr(ctxt, selector, &dt); if (dt.size < index * 8 + 7) return emulate_gp(ctxt, selector & 0xfffc); addr = dt.address + index * 8; return ctxt->ops->write_std(ctxt, addr, desc, sizeof *desc, &ctxt->exception); } /* Does not support long mode */ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, u16 selector, int seg) { struct desc_struct seg_desc, old_desc; u8 dpl, rpl, cpl; unsigned err_vec = GP_VECTOR; u32 err_code = 0; bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */ ulong desc_addr; int ret; u16 dummy; memset(&seg_desc, 0, sizeof seg_desc); if ((seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) || ctxt->mode == X86EMUL_MODE_REAL) { /* set real mode segment descriptor */ ctxt->ops->get_segment(ctxt, &dummy, &seg_desc, NULL, seg); set_desc_base(&seg_desc, selector << 4); goto load; } rpl = selector & 3; cpl = ctxt->ops->cpl(ctxt); /* NULL selector is not valid for TR, CS and SS (except for long mode) */ if ((seg == VCPU_SREG_CS || (seg == VCPU_SREG_SS && (ctxt->mode != X86EMUL_MODE_PROT64 || rpl != cpl)) || seg == VCPU_SREG_TR) && null_selector) goto exception; /* TR should be in GDT only */ if (seg == VCPU_SREG_TR && (selector & (1 << 2))) goto exception; if (null_selector) /* for NULL selector skip all following checks */ goto load; ret = read_segment_descriptor(ctxt, selector, &seg_desc, &desc_addr); if (ret != X86EMUL_CONTINUE) return ret; err_code = selector & 0xfffc; err_vec = GP_VECTOR; /* can't load system descriptor into segment selector */ if (seg <= VCPU_SREG_GS && !seg_desc.s) goto exception; if (!seg_desc.p) { err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR; goto exception; } dpl = seg_desc.dpl; switch (seg) { case VCPU_SREG_SS: /* * segment is not a writable data segment or segment * selector's RPL != CPL or segment selector's RPL != CPL */ if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl) goto exception; break; case VCPU_SREG_CS: if (!(seg_desc.type & 8)) goto exception; if (seg_desc.type & 4) { /* conforming */ if (dpl > cpl) goto exception; } else { /* nonconforming */ if (rpl > cpl || dpl != cpl) goto exception; } /* CS(RPL) <- CPL */ selector = (selector & 0xfffc) | cpl; break; case VCPU_SREG_TR: if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9)) goto exception; old_desc = seg_desc; seg_desc.type |= 2; /* busy */ ret = ctxt->ops->cmpxchg_emulated(ctxt, desc_addr, &old_desc, &seg_desc, sizeof(seg_desc), &ctxt->exception); if (ret != X86EMUL_CONTINUE) return ret; break; case VCPU_SREG_LDTR: if (seg_desc.s || seg_desc.type != 2) goto exception; break; default: /* DS, ES, FS, or GS */ /* * segment is not a data or readable code segment or * ((segment is a data or nonconforming code segment) * and (both RPL and CPL > DPL)) */ if ((seg_desc.type & 0xa) == 0x8 || (((seg_desc.type & 0xc) != 0xc) && (rpl > dpl && cpl > dpl))) goto exception; break; } if (seg_desc.s) { /* mark segment as accessed */ seg_desc.type |= 1; ret = write_segment_descriptor(ctxt, selector, &seg_desc); if (ret != X86EMUL_CONTINUE) return ret; } load: ctxt->ops->set_segment(ctxt, selector, &seg_desc, 0, seg); return X86EMUL_CONTINUE; exception: emulate_exception(ctxt, err_vec, err_code, true); return X86EMUL_PROPAGATE_FAULT; } static void write_register_operand(struct operand *op) { /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */ switch (op->bytes) { case 1: *(u8 *)op->addr.reg = (u8)op->val; break; case 2: *(u16 *)op->addr.reg = (u16)op->val; break; case 4: *op->addr.reg = (u32)op->val; break; /* 64b: zero-extend */ case 8: *op->addr.reg = op->val; break; } } static int writeback(struct x86_emulate_ctxt *ctxt) { int rc; if (ctxt->d & NoWrite) return X86EMUL_CONTINUE; switch (ctxt->dst.type) { case OP_REG: write_register_operand(&ctxt->dst); break; case OP_MEM: if (ctxt->lock_prefix) rc = segmented_cmpxchg(ctxt, ctxt->dst.addr.mem, &ctxt->dst.orig_val, &ctxt->dst.val, ctxt->dst.bytes); else rc = segmented_write(ctxt, ctxt->dst.addr.mem, &ctxt->dst.val, ctxt->dst.bytes); if (rc != X86EMUL_CONTINUE) return rc; break; case OP_MEM_STR: rc = segmented_write(ctxt, ctxt->dst.addr.mem, ctxt->dst.data, ctxt->dst.bytes * ctxt->dst.count); if (rc != X86EMUL_CONTINUE) return rc; break; case OP_XMM: write_sse_reg(ctxt, &ctxt->dst.vec_val, ctxt->dst.addr.xmm); break; case OP_MM: write_mmx_reg(ctxt, &ctxt->dst.mm_val, ctxt->dst.addr.mm); break; case OP_NONE: /* no writeback */ break; default: break; } return X86EMUL_CONTINUE; } static int push(struct x86_emulate_ctxt *ctxt, void *data, int bytes) { struct segmented_address addr; rsp_increment(ctxt, -bytes); addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt); addr.seg = VCPU_SREG_SS; return segmented_write(ctxt, addr, data, bytes); } static int em_push(struct x86_emulate_ctxt *ctxt) { /* Disable writeback. */ ctxt->dst.type = OP_NONE; return push(ctxt, &ctxt->src.val, ctxt->op_bytes); } static int emulate_pop(struct x86_emulate_ctxt *ctxt, void *dest, int len) { int rc; struct segmented_address addr; addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt); addr.seg = VCPU_SREG_SS; rc = segmented_read(ctxt, addr, dest, len); if (rc != X86EMUL_CONTINUE) return rc; rsp_increment(ctxt, len); return rc; } static int em_pop(struct x86_emulate_ctxt *ctxt) { return emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes); } static int emulate_popf(struct x86_emulate_ctxt *ctxt, void *dest, int len) { int rc; unsigned long val, change_mask; int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT; int cpl = ctxt->ops->cpl(ctxt); rc = emulate_pop(ctxt, &val, len); if (rc != X86EMUL_CONTINUE) return rc; change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF | EFLG_TF | EFLG_DF | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID; switch(ctxt->mode) { case X86EMUL_MODE_PROT64: case X86EMUL_MODE_PROT32: case X86EMUL_MODE_PROT16: if (cpl == 0) change_mask |= EFLG_IOPL; if (cpl <= iopl) change_mask |= EFLG_IF; break; case X86EMUL_MODE_VM86: if (iopl < 3) return emulate_gp(ctxt, 0); change_mask |= EFLG_IF; break; default: /* real mode */ change_mask |= (EFLG_IOPL | EFLG_IF); break; } *(unsigned long *)dest = (ctxt->eflags & ~change_mask) | (val & change_mask); return rc; } static int em_popf(struct x86_emulate_ctxt *ctxt) { ctxt->dst.type = OP_REG; ctxt->dst.addr.reg = &ctxt->eflags; ctxt->dst.bytes = ctxt->op_bytes; return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes); } static int em_enter(struct x86_emulate_ctxt *ctxt) { int rc; unsigned frame_size = ctxt->src.val; unsigned nesting_level = ctxt->src2.val & 31; ulong rbp; if (nesting_level) return X86EMUL_UNHANDLEABLE; rbp = reg_read(ctxt, VCPU_REGS_RBP); rc = push(ctxt, &rbp, stack_size(ctxt)); if (rc != X86EMUL_CONTINUE) return rc; assign_masked(reg_rmw(ctxt, VCPU_REGS_RBP), reg_read(ctxt, VCPU_REGS_RSP), stack_mask(ctxt)); assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), reg_read(ctxt, VCPU_REGS_RSP) - frame_size, stack_mask(ctxt)); return X86EMUL_CONTINUE; } static int em_leave(struct x86_emulate_ctxt *ctxt) { assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), reg_read(ctxt, VCPU_REGS_RBP), stack_mask(ctxt)); return emulate_pop(ctxt, reg_rmw(ctxt, VCPU_REGS_RBP), ctxt->op_bytes); } static int em_push_sreg(struct x86_emulate_ctxt *ctxt) { int seg = ctxt->src2.val; ctxt->src.val = get_segment_selector(ctxt, seg); return em_push(ctxt); } static int em_pop_sreg(struct x86_emulate_ctxt *ctxt) { int seg = ctxt->src2.val; unsigned long selector; int rc; rc = emulate_pop(ctxt, &selector, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; rc = load_segment_descriptor(ctxt, (u16)selector, seg); return rc; } static int em_pusha(struct x86_emulate_ctxt *ctxt) { unsigned long old_esp = reg_read(ctxt, VCPU_REGS_RSP); int rc = X86EMUL_CONTINUE; int reg = VCPU_REGS_RAX; while (reg <= VCPU_REGS_RDI) { (reg == VCPU_REGS_RSP) ? (ctxt->src.val = old_esp) : (ctxt->src.val = reg_read(ctxt, reg)); rc = em_push(ctxt); if (rc != X86EMUL_CONTINUE) return rc; ++reg; } return rc; } static int em_pushf(struct x86_emulate_ctxt *ctxt) { ctxt->src.val = (unsigned long)ctxt->eflags; return em_push(ctxt); } static int em_popa(struct x86_emulate_ctxt *ctxt) { int rc = X86EMUL_CONTINUE; int reg = VCPU_REGS_RDI; while (reg >= VCPU_REGS_RAX) { if (reg == VCPU_REGS_RSP) { rsp_increment(ctxt, ctxt->op_bytes); --reg; } rc = emulate_pop(ctxt, reg_rmw(ctxt, reg), ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) break; --reg; } return rc; } static int __emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) { const struct x86_emulate_ops *ops = ctxt->ops; int rc; struct desc_ptr dt; gva_t cs_addr; gva_t eip_addr; u16 cs, eip; /* TODO: Add limit checks */ ctxt->src.val = ctxt->eflags; rc = em_push(ctxt); if (rc != X86EMUL_CONTINUE) return rc; ctxt->eflags &= ~(EFLG_IF | EFLG_TF | EFLG_AC); ctxt->src.val = get_segment_selector(ctxt, VCPU_SREG_CS); rc = em_push(ctxt); if (rc != X86EMUL_CONTINUE) return rc; ctxt->src.val = ctxt->_eip; rc = em_push(ctxt); if (rc != X86EMUL_CONTINUE) return rc; ops->get_idt(ctxt, &dt); eip_addr = dt.address + (irq << 2); cs_addr = dt.address + (irq << 2) + 2; rc = ops->read_std(ctxt, cs_addr, &cs, 2, &ctxt->exception); if (rc != X86EMUL_CONTINUE) return rc; rc = ops->read_std(ctxt, eip_addr, &eip, 2, &ctxt->exception); if (rc != X86EMUL_CONTINUE) return rc; rc = load_segment_descriptor(ctxt, cs, VCPU_SREG_CS); if (rc != X86EMUL_CONTINUE) return rc; ctxt->_eip = eip; return rc; } int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) { int rc; invalidate_registers(ctxt); rc = __emulate_int_real(ctxt, irq); if (rc == X86EMUL_CONTINUE) writeback_registers(ctxt); return rc; } static int emulate_int(struct x86_emulate_ctxt *ctxt, int irq) { switch(ctxt->mode) { case X86EMUL_MODE_REAL: return __emulate_int_real(ctxt, irq); case X86EMUL_MODE_VM86: case X86EMUL_MODE_PROT16: case X86EMUL_MODE_PROT32: case X86EMUL_MODE_PROT64: default: /* Protected mode interrupts unimplemented yet */ return X86EMUL_UNHANDLEABLE; } } static int emulate_iret_real(struct x86_emulate_ctxt *ctxt) { int rc = X86EMUL_CONTINUE; unsigned long temp_eip = 0; unsigned long temp_eflags = 0; unsigned long cs = 0; unsigned long mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_TF | EFLG_IF | EFLG_DF | EFLG_OF | EFLG_IOPL | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID | (1 << 1); /* Last one is the reserved bit */ unsigned long vm86_mask = EFLG_VM | EFLG_VIF | EFLG_VIP; /* TODO: Add stack limit check */ rc = emulate_pop(ctxt, &temp_eip, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; if (temp_eip & ~0xffff) return emulate_gp(ctxt, 0); rc = emulate_pop(ctxt, &cs, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; rc = emulate_pop(ctxt, &temp_eflags, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS); if (rc != X86EMUL_CONTINUE) return rc; ctxt->_eip = temp_eip; if (ctxt->op_bytes == 4) ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask)); else if (ctxt->op_bytes == 2) { ctxt->eflags &= ~0xffff; ctxt->eflags |= temp_eflags; } ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */ ctxt->eflags |= EFLG_RESERVED_ONE_MASK; return rc; } static int em_iret(struct x86_emulate_ctxt *ctxt) { switch(ctxt->mode) { case X86EMUL_MODE_REAL: return emulate_iret_real(ctxt); case X86EMUL_MODE_VM86: case X86EMUL_MODE_PROT16: case X86EMUL_MODE_PROT32: case X86EMUL_MODE_PROT64: default: /* iret from protected mode unimplemented yet */ return X86EMUL_UNHANDLEABLE; } } static int em_jmp_far(struct x86_emulate_ctxt *ctxt) { int rc; unsigned short sel; memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); rc = load_segment_descriptor(ctxt, sel, VCPU_SREG_CS); if (rc != X86EMUL_CONTINUE) return rc; ctxt->_eip = 0; memcpy(&ctxt->_eip, ctxt->src.valptr, ctxt->op_bytes); return X86EMUL_CONTINUE; } static int em_grp2(struct x86_emulate_ctxt *ctxt) { switch (ctxt->modrm_reg) { case 0: /* rol */ emulate_2op_SrcB(ctxt, "rol"); break; case 1: /* ror */ emulate_2op_SrcB(ctxt, "ror"); break; case 2: /* rcl */ emulate_2op_SrcB(ctxt, "rcl"); break; case 3: /* rcr */ emulate_2op_SrcB(ctxt, "rcr"); break; case 4: /* sal/shl */ case 6: /* sal/shl */ emulate_2op_SrcB(ctxt, "sal"); break; case 5: /* shr */ emulate_2op_SrcB(ctxt, "shr"); break; case 7: /* sar */ emulate_2op_SrcB(ctxt, "sar"); break; } return X86EMUL_CONTINUE; } static int em_not(struct x86_emulate_ctxt *ctxt) { ctxt->dst.val = ~ctxt->dst.val; return X86EMUL_CONTINUE; } static int em_neg(struct x86_emulate_ctxt *ctxt) { emulate_1op(ctxt, "neg"); return X86EMUL_CONTINUE; } static int em_mul_ex(struct x86_emulate_ctxt *ctxt) { u8 ex = 0; emulate_1op_rax_rdx(ctxt, "mul", ex); return X86EMUL_CONTINUE; } static int em_imul_ex(struct x86_emulate_ctxt *ctxt) { u8 ex = 0; emulate_1op_rax_rdx(ctxt, "imul", ex); return X86EMUL_CONTINUE; } static int em_div_ex(struct x86_emulate_ctxt *ctxt) { u8 de = 0; emulate_1op_rax_rdx(ctxt, "div", de); if (de) return emulate_de(ctxt); return X86EMUL_CONTINUE; } static int em_idiv_ex(struct x86_emulate_ctxt *ctxt) { u8 de = 0; emulate_1op_rax_rdx(ctxt, "idiv", de); if (de) return emulate_de(ctxt); return X86EMUL_CONTINUE; } static int em_grp45(struct x86_emulate_ctxt *ctxt) { int rc = X86EMUL_CONTINUE; switch (ctxt->modrm_reg) { case 0: /* inc */ emulate_1op(ctxt, "inc"); break; case 1: /* dec */ emulate_1op(ctxt, "dec"); break; case 2: /* call near abs */ { long int old_eip; old_eip = ctxt->_eip; ctxt->_eip = ctxt->src.val; ctxt->src.val = old_eip; rc = em_push(ctxt); break; } case 4: /* jmp abs */ ctxt->_eip = ctxt->src.val; break; case 5: /* jmp far */ rc = em_jmp_far(ctxt); break; case 6: /* push */ rc = em_push(ctxt); break; } return rc; } static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt) { u64 old = ctxt->dst.orig_val64; if (((u32) (old >> 0) != (u32) reg_read(ctxt, VCPU_REGS_RAX)) || ((u32) (old >> 32) != (u32) reg_read(ctxt, VCPU_REGS_RDX))) { *reg_write(ctxt, VCPU_REGS_RAX) = (u32) (old >> 0); *reg_write(ctxt, VCPU_REGS_RDX) = (u32) (old >> 32); ctxt->eflags &= ~EFLG_ZF; } else { ctxt->dst.val64 = ((u64)reg_read(ctxt, VCPU_REGS_RCX) << 32) | (u32) reg_read(ctxt, VCPU_REGS_RBX); ctxt->eflags |= EFLG_ZF; } return X86EMUL_CONTINUE; } static int em_ret(struct x86_emulate_ctxt *ctxt) { ctxt->dst.type = OP_REG; ctxt->dst.addr.reg = &ctxt->_eip; ctxt->dst.bytes = ctxt->op_bytes; return em_pop(ctxt); } static int em_ret_far(struct x86_emulate_ctxt *ctxt) { int rc; unsigned long cs; rc = emulate_pop(ctxt, &ctxt->_eip, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; if (ctxt->op_bytes == 4) ctxt->_eip = (u32)ctxt->_eip; rc = emulate_pop(ctxt, &cs, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS); return rc; } static int em_cmpxchg(struct x86_emulate_ctxt *ctxt) { /* Save real source value, then compare EAX against destination. */ ctxt->src.orig_val = ctxt->src.val; ctxt->src.val = reg_read(ctxt, VCPU_REGS_RAX); emulate_2op_SrcV(ctxt, "cmp"); if (ctxt->eflags & EFLG_ZF) { /* Success: write back to memory. */ ctxt->dst.val = ctxt->src.orig_val; } else { /* Failure: write the value we saw to EAX. */ ctxt->dst.type = OP_REG; ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); } return X86EMUL_CONTINUE; } static int em_lseg(struct x86_emulate_ctxt *ctxt) { int seg = ctxt->src2.val; unsigned short sel; int rc; memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); rc = load_segment_descriptor(ctxt, sel, seg); if (rc != X86EMUL_CONTINUE) return rc; ctxt->dst.val = ctxt->src.val; return rc; } static void setup_syscalls_segments(struct x86_emulate_ctxt *ctxt, struct desc_struct *cs, struct desc_struct *ss) { cs->l = 0; /* will be adjusted later */ set_desc_base(cs, 0); /* flat segment */ cs->g = 1; /* 4kb granularity */ set_desc_limit(cs, 0xfffff); /* 4GB limit */ cs->type = 0x0b; /* Read, Execute, Accessed */ cs->s = 1; cs->dpl = 0; /* will be adjusted later */ cs->p = 1; cs->d = 1; cs->avl = 0; set_desc_base(ss, 0); /* flat segment */ set_desc_limit(ss, 0xfffff); /* 4GB limit */ ss->g = 1; /* 4kb granularity */ ss->s = 1; ss->type = 0x03; /* Read/Write, Accessed */ ss->d = 1; /* 32bit stack segment */ ss->dpl = 0; ss->p = 1; ss->l = 0; ss->avl = 0; } static bool vendor_intel(struct x86_emulate_ctxt *ctxt) { u32 eax, ebx, ecx, edx; eax = ecx = 0; ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); return ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx && ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx && edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx; } static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt) { const struct x86_emulate_ops *ops = ctxt->ops; u32 eax, ebx, ecx, edx; /* * syscall should always be enabled in longmode - so only become * vendor specific (cpuid) if other modes are active... */ if (ctxt->mode == X86EMUL_MODE_PROT64) return true; eax = 0x00000000; ecx = 0x00000000; ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); /* * Intel ("GenuineIntel") * remark: Intel CPUs only support "syscall" in 64bit * longmode. Also an 64bit guest with a * 32bit compat-app running will #UD !! While this * behaviour can be fixed (by emulating) into AMD * response - CPUs of AMD can't behave like Intel. */ if (ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx && ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx && edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx) return false; /* AMD ("AuthenticAMD") */ if (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx && ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx && edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx) return true; /* AMD ("AMDisbetter!") */ if (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx && ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx && edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx) return true; /* default: (not Intel, not AMD), apply Intel's stricter rules... */ return false; } static int em_syscall(struct x86_emulate_ctxt *ctxt) { const struct x86_emulate_ops *ops = ctxt->ops; struct desc_struct cs, ss; u64 msr_data; u16 cs_sel, ss_sel; u64 efer = 0; /* syscall is not available in real mode */ if (ctxt->mode == X86EMUL_MODE_REAL || ctxt->mode == X86EMUL_MODE_VM86) return emulate_ud(ctxt); if (!(em_syscall_is_enabled(ctxt))) return emulate_ud(ctxt); ops->get_msr(ctxt, MSR_EFER, &efer); setup_syscalls_segments(ctxt, &cs, &ss); if (!(efer & EFER_SCE)) return emulate_ud(ctxt); ops->get_msr(ctxt, MSR_STAR, &msr_data); msr_data >>= 32; cs_sel = (u16)(msr_data & 0xfffc); ss_sel = (u16)(msr_data + 8); if (efer & EFER_LMA) { cs.d = 0; cs.l = 1; } ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); *reg_write(ctxt, VCPU_REGS_RCX) = ctxt->_eip; if (efer & EFER_LMA) { #ifdef CONFIG_X86_64 *reg_write(ctxt, VCPU_REGS_R11) = ctxt->eflags & ~EFLG_RF; ops->get_msr(ctxt, ctxt->mode == X86EMUL_MODE_PROT64 ? MSR_LSTAR : MSR_CSTAR, &msr_data); ctxt->_eip = msr_data; ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data); ctxt->eflags &= ~(msr_data | EFLG_RF); #endif } else { /* legacy mode */ ops->get_msr(ctxt, MSR_STAR, &msr_data); ctxt->_eip = (u32)msr_data; ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF); } return X86EMUL_CONTINUE; } static int em_sysenter(struct x86_emulate_ctxt *ctxt) { const struct x86_emulate_ops *ops = ctxt->ops; struct desc_struct cs, ss; u64 msr_data; u16 cs_sel, ss_sel; u64 efer = 0; ops->get_msr(ctxt, MSR_EFER, &efer); /* inject #GP if in real mode */ if (ctxt->mode == X86EMUL_MODE_REAL) return emulate_gp(ctxt, 0); /* * Not recognized on AMD in compat mode (but is recognized in legacy * mode). */ if ((ctxt->mode == X86EMUL_MODE_PROT32) && (efer & EFER_LMA) && !vendor_intel(ctxt)) return emulate_ud(ctxt); /* XXX sysenter/sysexit have not been tested in 64bit mode. * Therefore, we inject an #UD. */ if (ctxt->mode == X86EMUL_MODE_PROT64) return emulate_ud(ctxt); setup_syscalls_segments(ctxt, &cs, &ss); ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); switch (ctxt->mode) { case X86EMUL_MODE_PROT32: if ((msr_data & 0xfffc) == 0x0) return emulate_gp(ctxt, 0); break; case X86EMUL_MODE_PROT64: if (msr_data == 0x0) return emulate_gp(ctxt, 0); break; default: break; } ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF); cs_sel = (u16)msr_data; cs_sel &= ~SELECTOR_RPL_MASK; ss_sel = cs_sel + 8; ss_sel &= ~SELECTOR_RPL_MASK; if (ctxt->mode == X86EMUL_MODE_PROT64 || (efer & EFER_LMA)) { cs.d = 0; cs.l = 1; } ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data); ctxt->_eip = msr_data; ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data); *reg_write(ctxt, VCPU_REGS_RSP) = msr_data; return X86EMUL_CONTINUE; } static int em_sysexit(struct x86_emulate_ctxt *ctxt) { const struct x86_emulate_ops *ops = ctxt->ops; struct desc_struct cs, ss; u64 msr_data; int usermode; u16 cs_sel = 0, ss_sel = 0; /* inject #GP if in real mode or Virtual 8086 mode */ if (ctxt->mode == X86EMUL_MODE_REAL || ctxt->mode == X86EMUL_MODE_VM86) return emulate_gp(ctxt, 0); setup_syscalls_segments(ctxt, &cs, &ss); if ((ctxt->rex_prefix & 0x8) != 0x0) usermode = X86EMUL_MODE_PROT64; else usermode = X86EMUL_MODE_PROT32; cs.dpl = 3; ss.dpl = 3; ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); switch (usermode) { case X86EMUL_MODE_PROT32: cs_sel = (u16)(msr_data + 16); if ((msr_data & 0xfffc) == 0x0) return emulate_gp(ctxt, 0); ss_sel = (u16)(msr_data + 24); break; case X86EMUL_MODE_PROT64: cs_sel = (u16)(msr_data + 32); if (msr_data == 0x0) return emulate_gp(ctxt, 0); ss_sel = cs_sel + 8; cs.d = 0; cs.l = 1; break; } cs_sel |= SELECTOR_RPL_MASK; ss_sel |= SELECTOR_RPL_MASK; ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); ctxt->_eip = reg_read(ctxt, VCPU_REGS_RDX); *reg_write(ctxt, VCPU_REGS_RSP) = reg_read(ctxt, VCPU_REGS_RCX); return X86EMUL_CONTINUE; } static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt) { int iopl; if (ctxt->mode == X86EMUL_MODE_REAL) return false; if (ctxt->mode == X86EMUL_MODE_VM86) return true; iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT; return ctxt->ops->cpl(ctxt) > iopl; } static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt, u16 port, u16 len) { const struct x86_emulate_ops *ops = ctxt->ops; struct desc_struct tr_seg; u32 base3; int r; u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7; unsigned mask = (1 << len) - 1; unsigned long base; ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR); if (!tr_seg.p) return false; if (desc_limit_scaled(&tr_seg) < 103) return false; base = get_desc_base(&tr_seg); #ifdef CONFIG_X86_64 base |= ((u64)base3) << 32; #endif r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL); if (r != X86EMUL_CONTINUE) return false; if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg)) return false; r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL); if (r != X86EMUL_CONTINUE) return false; if ((perm >> bit_idx) & mask) return false; return true; } static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt, u16 port, u16 len) { if (ctxt->perm_ok) return true; if (emulator_bad_iopl(ctxt)) if (!emulator_io_port_access_allowed(ctxt, port, len)) return false; ctxt->perm_ok = true; return true; } static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt, struct tss_segment_16 *tss) { tss->ip = ctxt->_eip; tss->flag = ctxt->eflags; tss->ax = reg_read(ctxt, VCPU_REGS_RAX); tss->cx = reg_read(ctxt, VCPU_REGS_RCX); tss->dx = reg_read(ctxt, VCPU_REGS_RDX); tss->bx = reg_read(ctxt, VCPU_REGS_RBX); tss->sp = reg_read(ctxt, VCPU_REGS_RSP); tss->bp = reg_read(ctxt, VCPU_REGS_RBP); tss->si = reg_read(ctxt, VCPU_REGS_RSI); tss->di = reg_read(ctxt, VCPU_REGS_RDI); tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR); } static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt, struct tss_segment_16 *tss) { int ret; ctxt->_eip = tss->ip; ctxt->eflags = tss->flag | 2; *reg_write(ctxt, VCPU_REGS_RAX) = tss->ax; *reg_write(ctxt, VCPU_REGS_RCX) = tss->cx; *reg_write(ctxt, VCPU_REGS_RDX) = tss->dx; *reg_write(ctxt, VCPU_REGS_RBX) = tss->bx; *reg_write(ctxt, VCPU_REGS_RSP) = tss->sp; *reg_write(ctxt, VCPU_REGS_RBP) = tss->bp; *reg_write(ctxt, VCPU_REGS_RSI) = tss->si; *reg_write(ctxt, VCPU_REGS_RDI) = tss->di; /* * SDM says that segment selectors are loaded before segment * descriptors */ set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR); set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); /* * Now load segment descriptors. If fault happens at this stage * it is handled in a context of new task */ ret = load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS); if (ret != X86EMUL_CONTINUE) return ret; return X86EMUL_CONTINUE; } static int task_switch_16(struct x86_emulate_ctxt *ctxt, u16 tss_selector, u16 old_tss_sel, ulong old_tss_base, struct desc_struct *new_desc) { const struct x86_emulate_ops *ops = ctxt->ops; struct tss_segment_16 tss_seg; int ret; u32 new_tss_base = get_desc_base(new_desc); ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg, &ctxt->exception); if (ret != X86EMUL_CONTINUE) /* FIXME: need to provide precise fault address */ return ret; save_state_to_tss16(ctxt, &tss_seg); ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg, &ctxt->exception); if (ret != X86EMUL_CONTINUE) /* FIXME: need to provide precise fault address */ return ret; ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg, &ctxt->exception); if (ret != X86EMUL_CONTINUE) /* FIXME: need to provide precise fault address */ return ret; if (old_tss_sel != 0xffff) { tss_seg.prev_task_link = old_tss_sel; ret = ops->write_std(ctxt, new_tss_base, &tss_seg.prev_task_link, sizeof tss_seg.prev_task_link, &ctxt->exception); if (ret != X86EMUL_CONTINUE) /* FIXME: need to provide precise fault address */ return ret; } return load_state_from_tss16(ctxt, &tss_seg); } static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, struct tss_segment_32 *tss) { tss->cr3 = ctxt->ops->get_cr(ctxt, 3); tss->eip = ctxt->_eip; tss->eflags = ctxt->eflags; tss->eax = reg_read(ctxt, VCPU_REGS_RAX); tss->ecx = reg_read(ctxt, VCPU_REGS_RCX); tss->edx = reg_read(ctxt, VCPU_REGS_RDX); tss->ebx = reg_read(ctxt, VCPU_REGS_RBX); tss->esp = reg_read(ctxt, VCPU_REGS_RSP); tss->ebp = reg_read(ctxt, VCPU_REGS_RBP); tss->esi = reg_read(ctxt, VCPU_REGS_RSI); tss->edi = reg_read(ctxt, VCPU_REGS_RDI); tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS); tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS); tss->ldt_selector = get_segment_selector(ctxt, VCPU_SREG_LDTR); } static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, struct tss_segment_32 *tss) { int ret; if (ctxt->ops->set_cr(ctxt, 3, tss->cr3)) return emulate_gp(ctxt, 0); ctxt->_eip = tss->eip; ctxt->eflags = tss->eflags | 2; /* General purpose registers */ *reg_write(ctxt, VCPU_REGS_RAX) = tss->eax; *reg_write(ctxt, VCPU_REGS_RCX) = tss->ecx; *reg_write(ctxt, VCPU_REGS_RDX) = tss->edx; *reg_write(ctxt, VCPU_REGS_RBX) = tss->ebx; *reg_write(ctxt, VCPU_REGS_RSP) = tss->esp; *reg_write(ctxt, VCPU_REGS_RBP) = tss->ebp; *reg_write(ctxt, VCPU_REGS_RSI) = tss->esi; *reg_write(ctxt, VCPU_REGS_RDI) = tss->edi; /* * SDM says that segment selectors are loaded before segment * descriptors */ set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR); set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS); set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS); /* * If we're switching between Protected Mode and VM86, we need to make * sure to update the mode before loading the segment descriptors so * that the selectors are interpreted correctly. * * Need to get rflags to the vcpu struct immediately because it * influences the CPL which is checked at least when loading the segment * descriptors and when pushing an error code to the new kernel stack. * * TODO Introduce a separate ctxt->ops->set_cpl callback */ if (ctxt->eflags & X86_EFLAGS_VM) ctxt->mode = X86EMUL_MODE_VM86; else ctxt->mode = X86EMUL_MODE_PROT32; ctxt->ops->set_rflags(ctxt, ctxt->eflags); /* * Now load segment descriptors. If fault happenes at this stage * it is handled in a context of new task */ ret = load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS); if (ret != X86EMUL_CONTINUE) return ret; return X86EMUL_CONTINUE; } static int task_switch_32(struct x86_emulate_ctxt *ctxt, u16 tss_selector, u16 old_tss_sel, ulong old_tss_base, struct desc_struct *new_desc) { const struct x86_emulate_ops *ops = ctxt->ops; struct tss_segment_32 tss_seg; int ret; u32 new_tss_base = get_desc_base(new_desc); ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg, &ctxt->exception); if (ret != X86EMUL_CONTINUE) /* FIXME: need to provide precise fault address */ return ret; save_state_to_tss32(ctxt, &tss_seg); ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg, &ctxt->exception); if (ret != X86EMUL_CONTINUE) /* FIXME: need to provide precise fault address */ return ret; ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg, &ctxt->exception); if (ret != X86EMUL_CONTINUE) /* FIXME: need to provide precise fault address */ return ret; if (old_tss_sel != 0xffff) { tss_seg.prev_task_link = old_tss_sel; ret = ops->write_std(ctxt, new_tss_base, &tss_seg.prev_task_link, sizeof tss_seg.prev_task_link, &ctxt->exception); if (ret != X86EMUL_CONTINUE) /* FIXME: need to provide precise fault address */ return ret; } return load_state_from_tss32(ctxt, &tss_seg); } static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, u16 tss_selector, int idt_index, int reason, bool has_error_code, u32 error_code) { const struct x86_emulate_ops *ops = ctxt->ops; struct desc_struct curr_tss_desc, next_tss_desc; int ret; u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR); ulong old_tss_base = ops->get_cached_segment_base(ctxt, VCPU_SREG_TR); u32 desc_limit; ulong desc_addr; /* FIXME: old_tss_base == ~0 ? */ ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc, &desc_addr); if (ret != X86EMUL_CONTINUE) return ret; ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc, &desc_addr); if (ret != X86EMUL_CONTINUE) return ret; /* FIXME: check that next_tss_desc is tss */ /* * Check privileges. The three cases are task switch caused by... * * 1. jmp/call/int to task gate: Check against DPL of the task gate * 2. Exception/IRQ/iret: No check is performed * 3. jmp/call to TSS: Check against DPL of the TSS */ if (reason == TASK_SWITCH_GATE) { if (idt_index != -1) { /* Software interrupts */ struct desc_struct task_gate_desc; int dpl; ret = read_interrupt_descriptor(ctxt, idt_index, &task_gate_desc); if (ret != X86EMUL_CONTINUE) return ret; dpl = task_gate_desc.dpl; if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl) return emulate_gp(ctxt, (idt_index << 3) | 0x2); } } else if (reason != TASK_SWITCH_IRET) { int dpl = next_tss_desc.dpl; if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl) return emulate_gp(ctxt, tss_selector); } desc_limit = desc_limit_scaled(&next_tss_desc); if (!next_tss_desc.p || ((desc_limit < 0x67 && (next_tss_desc.type & 8)) || desc_limit < 0x2b)) { emulate_ts(ctxt, tss_selector & 0xfffc); return X86EMUL_PROPAGATE_FAULT; } if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) { curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */ write_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc); } if (reason == TASK_SWITCH_IRET) ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT; /* set back link to prev task only if NT bit is set in eflags note that old_tss_sel is not used after this point */ if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE) old_tss_sel = 0xffff; if (next_tss_desc.type & 8) ret = task_switch_32(ctxt, tss_selector, old_tss_sel, old_tss_base, &next_tss_desc); else ret = task_switch_16(ctxt, tss_selector, old_tss_sel, old_tss_base, &next_tss_desc); if (ret != X86EMUL_CONTINUE) return ret; if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE) ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT; if (reason != TASK_SWITCH_IRET) { next_tss_desc.type |= (1 << 1); /* set busy flag */ write_segment_descriptor(ctxt, tss_selector, &next_tss_desc); } ops->set_cr(ctxt, 0, ops->get_cr(ctxt, 0) | X86_CR0_TS); ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR); if (has_error_code) { ctxt->op_bytes = ctxt->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2; ctxt->lock_prefix = 0; ctxt->src.val = (unsigned long) error_code; ret = em_push(ctxt); } return ret; } int emulator_task_switch(struct x86_emulate_ctxt *ctxt, u16 tss_selector, int idt_index, int reason, bool has_error_code, u32 error_code) { int rc; invalidate_registers(ctxt); ctxt->_eip = ctxt->eip; ctxt->dst.type = OP_NONE; rc = emulator_do_task_switch(ctxt, tss_selector, idt_index, reason, has_error_code, error_code); if (rc == X86EMUL_CONTINUE) { ctxt->eip = ctxt->_eip; writeback_registers(ctxt); } return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; } static void string_addr_inc(struct x86_emulate_ctxt *ctxt, int reg, struct operand *op) { int df = (ctxt->eflags & EFLG_DF) ? -op->count : op->count; register_address_increment(ctxt, reg_rmw(ctxt, reg), df * op->bytes); op->addr.mem.ea = register_address(ctxt, reg_read(ctxt, reg)); } static int em_das(struct x86_emulate_ctxt *ctxt) { u8 al, old_al; bool af, cf, old_cf; cf = ctxt->eflags & X86_EFLAGS_CF; al = ctxt->dst.val; old_al = al; old_cf = cf; cf = false; af = ctxt->eflags & X86_EFLAGS_AF; if ((al & 0x0f) > 9 || af) { al -= 6; cf = old_cf | (al >= 250); af = true; } else { af = false; } if (old_al > 0x99 || old_cf) { al -= 0x60; cf = true; } ctxt->dst.val = al; /* Set PF, ZF, SF */ ctxt->src.type = OP_IMM; ctxt->src.val = 0; ctxt->src.bytes = 1; emulate_2op_SrcV(ctxt, "or"); ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF); if (cf) ctxt->eflags |= X86_EFLAGS_CF; if (af) ctxt->eflags |= X86_EFLAGS_AF; return X86EMUL_CONTINUE; } static int em_aad(struct x86_emulate_ctxt *ctxt) { u8 al = ctxt->dst.val & 0xff; u8 ah = (ctxt->dst.val >> 8) & 0xff; al = (al + (ah * ctxt->src.val)) & 0xff; ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al; ctxt->eflags &= ~(X86_EFLAGS_PF | X86_EFLAGS_SF | X86_EFLAGS_ZF); if (!al) ctxt->eflags |= X86_EFLAGS_ZF; if (!(al & 1)) ctxt->eflags |= X86_EFLAGS_PF; if (al & 0x80) ctxt->eflags |= X86_EFLAGS_SF; return X86EMUL_CONTINUE; } static int em_call(struct x86_emulate_ctxt *ctxt) { long rel = ctxt->src.val; ctxt->src.val = (unsigned long)ctxt->_eip; jmp_rel(ctxt, rel); return em_push(ctxt); } static int em_call_far(struct x86_emulate_ctxt *ctxt) { u16 sel, old_cs; ulong old_eip; int rc; old_cs = get_segment_selector(ctxt, VCPU_SREG_CS); old_eip = ctxt->_eip; memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); if (load_segment_descriptor(ctxt, sel, VCPU_SREG_CS)) return X86EMUL_CONTINUE; ctxt->_eip = 0; memcpy(&ctxt->_eip, ctxt->src.valptr, ctxt->op_bytes); ctxt->src.val = old_cs; rc = em_push(ctxt); if (rc != X86EMUL_CONTINUE) return rc; ctxt->src.val = old_eip; return em_push(ctxt); } static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt) { int rc; ctxt->dst.type = OP_REG; ctxt->dst.addr.reg = &ctxt->_eip; ctxt->dst.bytes = ctxt->op_bytes; rc = emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; rsp_increment(ctxt, ctxt->src.val); return X86EMUL_CONTINUE; } static int em_add(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV(ctxt, "add"); return X86EMUL_CONTINUE; } static int em_or(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV(ctxt, "or"); return X86EMUL_CONTINUE; } static int em_adc(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV(ctxt, "adc"); return X86EMUL_CONTINUE; } static int em_sbb(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV(ctxt, "sbb"); return X86EMUL_CONTINUE; } static int em_and(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV(ctxt, "and"); return X86EMUL_CONTINUE; } static int em_sub(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV(ctxt, "sub"); return X86EMUL_CONTINUE; } static int em_xor(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV(ctxt, "xor"); return X86EMUL_CONTINUE; } static int em_cmp(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV(ctxt, "cmp"); /* Disable writeback. */ ctxt->dst.type = OP_NONE; return X86EMUL_CONTINUE; } static int em_test(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV(ctxt, "test"); /* Disable writeback. */ ctxt->dst.type = OP_NONE; return X86EMUL_CONTINUE; } static int em_xchg(struct x86_emulate_ctxt *ctxt) { /* Write back the register source. */ ctxt->src.val = ctxt->dst.val; write_register_operand(&ctxt->src); /* Write back the memory destination with implicit LOCK prefix. */ ctxt->dst.val = ctxt->src.orig_val; ctxt->lock_prefix = 1; return X86EMUL_CONTINUE; } static int em_imul(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV_nobyte(ctxt, "imul"); return X86EMUL_CONTINUE; } static int em_imul_3op(struct x86_emulate_ctxt *ctxt) { ctxt->dst.val = ctxt->src2.val; return em_imul(ctxt); } static int em_cwd(struct x86_emulate_ctxt *ctxt) { ctxt->dst.type = OP_REG; ctxt->dst.bytes = ctxt->src.bytes; ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); ctxt->dst.val = ~((ctxt->src.val >> (ctxt->src.bytes * 8 - 1)) - 1); return X86EMUL_CONTINUE; } static int em_rdtsc(struct x86_emulate_ctxt *ctxt) { u64 tsc = 0; ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc); *reg_write(ctxt, VCPU_REGS_RAX) = (u32)tsc; *reg_write(ctxt, VCPU_REGS_RDX) = tsc >> 32; return X86EMUL_CONTINUE; } static int em_rdpmc(struct x86_emulate_ctxt *ctxt) { u64 pmc; if (ctxt->ops->read_pmc(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &pmc)) return emulate_gp(ctxt, 0); *reg_write(ctxt, VCPU_REGS_RAX) = (u32)pmc; *reg_write(ctxt, VCPU_REGS_RDX) = pmc >> 32; return X86EMUL_CONTINUE; } static int em_mov(struct x86_emulate_ctxt *ctxt) { memcpy(ctxt->dst.valptr, ctxt->src.valptr, ctxt->op_bytes); return X86EMUL_CONTINUE; } static int em_cr_write(struct x86_emulate_ctxt *ctxt) { if (ctxt->ops->set_cr(ctxt, ctxt->modrm_reg, ctxt->src.val)) return emulate_gp(ctxt, 0); /* Disable writeback. */ ctxt->dst.type = OP_NONE; return X86EMUL_CONTINUE; } static int em_dr_write(struct x86_emulate_ctxt *ctxt) { unsigned long val; if (ctxt->mode == X86EMUL_MODE_PROT64) val = ctxt->src.val & ~0ULL; else val = ctxt->src.val & ~0U; /* #UD condition is already handled. */ if (ctxt->ops->set_dr(ctxt, ctxt->modrm_reg, val) < 0) return emulate_gp(ctxt, 0); /* Disable writeback. */ ctxt->dst.type = OP_NONE; return X86EMUL_CONTINUE; } static int em_wrmsr(struct x86_emulate_ctxt *ctxt) { u64 msr_data; msr_data = (u32)reg_read(ctxt, VCPU_REGS_RAX) | ((u64)reg_read(ctxt, VCPU_REGS_RDX) << 32); if (ctxt->ops->set_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), msr_data)) return emulate_gp(ctxt, 0); return X86EMUL_CONTINUE; } static int em_rdmsr(struct x86_emulate_ctxt *ctxt) { u64 msr_data; if (ctxt->ops->get_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &msr_data)) return emulate_gp(ctxt, 0); *reg_write(ctxt, VCPU_REGS_RAX) = (u32)msr_data; *reg_write(ctxt, VCPU_REGS_RDX) = msr_data >> 32; return X86EMUL_CONTINUE; } static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt) { if (ctxt->modrm_reg > VCPU_SREG_GS) return emulate_ud(ctxt); ctxt->dst.val = get_segment_selector(ctxt, ctxt->modrm_reg); return X86EMUL_CONTINUE; } static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt) { u16 sel = ctxt->src.val; if (ctxt->modrm_reg == VCPU_SREG_CS || ctxt->modrm_reg > VCPU_SREG_GS) return emulate_ud(ctxt); if (ctxt->modrm_reg == VCPU_SREG_SS) ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS; /* Disable writeback. */ ctxt->dst.type = OP_NONE; return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg); } static int em_lldt(struct x86_emulate_ctxt *ctxt) { u16 sel = ctxt->src.val; /* Disable writeback. */ ctxt->dst.type = OP_NONE; return load_segment_descriptor(ctxt, sel, VCPU_SREG_LDTR); } static int em_ltr(struct x86_emulate_ctxt *ctxt) { u16 sel = ctxt->src.val; /* Disable writeback. */ ctxt->dst.type = OP_NONE; return load_segment_descriptor(ctxt, sel, VCPU_SREG_TR); } static int em_invlpg(struct x86_emulate_ctxt *ctxt) { int rc; ulong linear; rc = linearize(ctxt, ctxt->src.addr.mem, 1, false, &linear); if (rc == X86EMUL_CONTINUE) ctxt->ops->invlpg(ctxt, linear); /* Disable writeback. */ ctxt->dst.type = OP_NONE; return X86EMUL_CONTINUE; } static int em_clts(struct x86_emulate_ctxt *ctxt) { ulong cr0; cr0 = ctxt->ops->get_cr(ctxt, 0); cr0 &= ~X86_CR0_TS; ctxt->ops->set_cr(ctxt, 0, cr0); return X86EMUL_CONTINUE; } static int em_vmcall(struct x86_emulate_ctxt *ctxt) { int rc; if (ctxt->modrm_mod != 3 || ctxt->modrm_rm != 1) return X86EMUL_UNHANDLEABLE; rc = ctxt->ops->fix_hypercall(ctxt); if (rc != X86EMUL_CONTINUE) return rc; /* Let the processor re-execute the fixed hypercall */ ctxt->_eip = ctxt->eip; /* Disable writeback. */ ctxt->dst.type = OP_NONE; return X86EMUL_CONTINUE; } static int emulate_store_desc_ptr(struct x86_emulate_ctxt *ctxt, void (*get)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *ptr)) { struct desc_ptr desc_ptr; if (ctxt->mode == X86EMUL_MODE_PROT64) ctxt->op_bytes = 8; get(ctxt, &desc_ptr); if (ctxt->op_bytes == 2) { ctxt->op_bytes = 4; desc_ptr.address &= 0x00ffffff; } /* Disable writeback. */ ctxt->dst.type = OP_NONE; return segmented_write(ctxt, ctxt->dst.addr.mem, &desc_ptr, 2 + ctxt->op_bytes); } static int em_sgdt(struct x86_emulate_ctxt *ctxt) { return emulate_store_desc_ptr(ctxt, ctxt->ops->get_gdt); } static int em_sidt(struct x86_emulate_ctxt *ctxt) { return emulate_store_desc_ptr(ctxt, ctxt->ops->get_idt); } static int em_lgdt(struct x86_emulate_ctxt *ctxt) { struct desc_ptr desc_ptr; int rc; if (ctxt->mode == X86EMUL_MODE_PROT64) ctxt->op_bytes = 8; rc = read_descriptor(ctxt, ctxt->src.addr.mem, &desc_ptr.size, &desc_ptr.address, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; ctxt->ops->set_gdt(ctxt, &desc_ptr); /* Disable writeback. */ ctxt->dst.type = OP_NONE; return X86EMUL_CONTINUE; } static int em_vmmcall(struct x86_emulate_ctxt *ctxt) { int rc; rc = ctxt->ops->fix_hypercall(ctxt); /* Disable writeback. */ ctxt->dst.type = OP_NONE; return rc; } static int em_lidt(struct x86_emulate_ctxt *ctxt) { struct desc_ptr desc_ptr; int rc; if (ctxt->mode == X86EMUL_MODE_PROT64) ctxt->op_bytes = 8; rc = read_descriptor(ctxt, ctxt->src.addr.mem, &desc_ptr.size, &desc_ptr.address, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; ctxt->ops->set_idt(ctxt, &desc_ptr); /* Disable writeback. */ ctxt->dst.type = OP_NONE; return X86EMUL_CONTINUE; } static int em_smsw(struct x86_emulate_ctxt *ctxt) { ctxt->dst.bytes = 2; ctxt->dst.val = ctxt->ops->get_cr(ctxt, 0); return X86EMUL_CONTINUE; } static int em_lmsw(struct x86_emulate_ctxt *ctxt) { ctxt->ops->set_cr(ctxt, 0, (ctxt->ops->get_cr(ctxt, 0) & ~0x0eul) | (ctxt->src.val & 0x0f)); ctxt->dst.type = OP_NONE; return X86EMUL_CONTINUE; } static int em_loop(struct x86_emulate_ctxt *ctxt) { register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RCX), -1); if ((address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) != 0) && (ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags))) jmp_rel(ctxt, ctxt->src.val); return X86EMUL_CONTINUE; } static int em_jcxz(struct x86_emulate_ctxt *ctxt) { if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) jmp_rel(ctxt, ctxt->src.val); return X86EMUL_CONTINUE; } static int em_in(struct x86_emulate_ctxt *ctxt) { if (!pio_in_emulated(ctxt, ctxt->dst.bytes, ctxt->src.val, &ctxt->dst.val)) return X86EMUL_IO_NEEDED; return X86EMUL_CONTINUE; } static int em_out(struct x86_emulate_ctxt *ctxt) { ctxt->ops->pio_out_emulated(ctxt, ctxt->src.bytes, ctxt->dst.val, &ctxt->src.val, 1); /* Disable writeback. */ ctxt->dst.type = OP_NONE; return X86EMUL_CONTINUE; } static int em_cli(struct x86_emulate_ctxt *ctxt) { if (emulator_bad_iopl(ctxt)) return emulate_gp(ctxt, 0); ctxt->eflags &= ~X86_EFLAGS_IF; return X86EMUL_CONTINUE; } static int em_sti(struct x86_emulate_ctxt *ctxt) { if (emulator_bad_iopl(ctxt)) return emulate_gp(ctxt, 0); ctxt->interruptibility = KVM_X86_SHADOW_INT_STI; ctxt->eflags |= X86_EFLAGS_IF; return X86EMUL_CONTINUE; } static int em_bt(struct x86_emulate_ctxt *ctxt) { /* Disable writeback. */ ctxt->dst.type = OP_NONE; /* only subword offset */ ctxt->src.val &= (ctxt->dst.bytes << 3) - 1; emulate_2op_SrcV_nobyte(ctxt, "bt"); return X86EMUL_CONTINUE; } static int em_bts(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV_nobyte(ctxt, "bts"); return X86EMUL_CONTINUE; } static int em_btr(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV_nobyte(ctxt, "btr"); return X86EMUL_CONTINUE; } static int em_btc(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV_nobyte(ctxt, "btc"); return X86EMUL_CONTINUE; } static int em_bsf(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV_nobyte(ctxt, "bsf"); return X86EMUL_CONTINUE; } static int em_bsr(struct x86_emulate_ctxt *ctxt) { emulate_2op_SrcV_nobyte(ctxt, "bsr"); return X86EMUL_CONTINUE; } static int em_cpuid(struct x86_emulate_ctxt *ctxt) { u32 eax, ebx, ecx, edx; eax = reg_read(ctxt, VCPU_REGS_RAX); ecx = reg_read(ctxt, VCPU_REGS_RCX); ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); *reg_write(ctxt, VCPU_REGS_RAX) = eax; *reg_write(ctxt, VCPU_REGS_RBX) = ebx; *reg_write(ctxt, VCPU_REGS_RCX) = ecx; *reg_write(ctxt, VCPU_REGS_RDX) = edx; return X86EMUL_CONTINUE; } static int em_lahf(struct x86_emulate_ctxt *ctxt) { *reg_rmw(ctxt, VCPU_REGS_RAX) &= ~0xff00UL; *reg_rmw(ctxt, VCPU_REGS_RAX) |= (ctxt->eflags & 0xff) << 8; return X86EMUL_CONTINUE; } static int em_bswap(struct x86_emulate_ctxt *ctxt) { switch (ctxt->op_bytes) { #ifdef CONFIG_X86_64 case 8: asm("bswap %0" : "+r"(ctxt->dst.val)); break; #endif default: asm("bswap %0" : "+r"(*(u32 *)&ctxt->dst.val)); break; } return X86EMUL_CONTINUE; } static bool valid_cr(int nr) { switch (nr) { case 0: case 2 ... 4: case 8: return true; default: return false; } } static int check_cr_read(struct x86_emulate_ctxt *ctxt) { if (!valid_cr(ctxt->modrm_reg)) return emulate_ud(ctxt); return X86EMUL_CONTINUE; } static int check_cr_write(struct x86_emulate_ctxt *ctxt) { u64 new_val = ctxt->src.val64; int cr = ctxt->modrm_reg; u64 efer = 0; static u64 cr_reserved_bits[] = { 0xffffffff00000000ULL, 0, 0, 0, /* CR3 checked later */ CR4_RESERVED_BITS, 0, 0, 0, CR8_RESERVED_BITS, }; if (!valid_cr(cr)) return emulate_ud(ctxt); if (new_val & cr_reserved_bits[cr]) return emulate_gp(ctxt, 0); switch (cr) { case 0: { u64 cr4; if (((new_val & X86_CR0_PG) && !(new_val & X86_CR0_PE)) || ((new_val & X86_CR0_NW) && !(new_val & X86_CR0_CD))) return emulate_gp(ctxt, 0); cr4 = ctxt->ops->get_cr(ctxt, 4); ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); if ((new_val & X86_CR0_PG) && (efer & EFER_LME) && !(cr4 & X86_CR4_PAE)) return emulate_gp(ctxt, 0); break; } case 3: { u64 rsvd = 0; ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); if (efer & EFER_LMA) rsvd = CR3_L_MODE_RESERVED_BITS; else if (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_PAE) rsvd = CR3_PAE_RESERVED_BITS; else if (ctxt->ops->get_cr(ctxt, 0) & X86_CR0_PG) rsvd = CR3_NONPAE_RESERVED_BITS; if (new_val & rsvd) return emulate_gp(ctxt, 0); break; } case 4: { ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); if ((efer & EFER_LMA) && !(new_val & X86_CR4_PAE)) return emulate_gp(ctxt, 0); break; } } return X86EMUL_CONTINUE; } static int check_dr7_gd(struct x86_emulate_ctxt *ctxt) { unsigned long dr7; ctxt->ops->get_dr(ctxt, 7, &dr7); /* Check if DR7.Global_Enable is set */ return dr7 & (1 << 13); } static int check_dr_read(struct x86_emulate_ctxt *ctxt) { int dr = ctxt->modrm_reg; u64 cr4; if (dr > 7) return emulate_ud(ctxt); cr4 = ctxt->ops->get_cr(ctxt, 4); if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5)) return emulate_ud(ctxt); if (check_dr7_gd(ctxt)) return emulate_db(ctxt); return X86EMUL_CONTINUE; } static int check_dr_write(struct x86_emulate_ctxt *ctxt) { u64 new_val = ctxt->src.val64; int dr = ctxt->modrm_reg; if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL)) return emulate_gp(ctxt, 0); return check_dr_read(ctxt); } static int check_svme(struct x86_emulate_ctxt *ctxt) { u64 efer; ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); if (!(efer & EFER_SVME)) return emulate_ud(ctxt); return X86EMUL_CONTINUE; } static int check_svme_pa(struct x86_emulate_ctxt *ctxt) { u64 rax = reg_read(ctxt, VCPU_REGS_RAX); /* Valid physical address? */ if (rax & 0xffff000000000000ULL) return emulate_gp(ctxt, 0); return check_svme(ctxt); } static int check_rdtsc(struct x86_emulate_ctxt *ctxt) { u64 cr4 = ctxt->ops->get_cr(ctxt, 4); if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt)) return emulate_ud(ctxt); return X86EMUL_CONTINUE; } static int check_rdpmc(struct x86_emulate_ctxt *ctxt) { u64 cr4 = ctxt->ops->get_cr(ctxt, 4); u64 rcx = reg_read(ctxt, VCPU_REGS_RCX); if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) || (rcx > 3)) return emulate_gp(ctxt, 0); return X86EMUL_CONTINUE; } static int check_perm_in(struct x86_emulate_ctxt *ctxt) { ctxt->dst.bytes = min(ctxt->dst.bytes, 4u); if (!emulator_io_permited(ctxt, ctxt->src.val, ctxt->dst.bytes)) return emulate_gp(ctxt, 0); return X86EMUL_CONTINUE; } static int check_perm_out(struct x86_emulate_ctxt *ctxt) { ctxt->src.bytes = min(ctxt->src.bytes, 4u); if (!emulator_io_permited(ctxt, ctxt->dst.val, ctxt->src.bytes)) return emulate_gp(ctxt, 0); return X86EMUL_CONTINUE; } #define D(_y) { .flags = (_y) } #define DI(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i } #define DIP(_y, _i, _p) { .flags = (_y), .intercept = x86_intercept_##_i, \ .check_perm = (_p) } #define N D(0) #define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) } #define G(_f, _g) { .flags = ((_f) | Group | ModRM), .u.group = (_g) } #define GD(_f, _g) { .flags = ((_f) | GroupDual | ModRM), .u.gdual = (_g) } #define E(_f, _e) { .flags = ((_f) | Escape | ModRM), .u.esc = (_e) } #define I(_f, _e) { .flags = (_f), .u.execute = (_e) } #define F(_f, _e) { .flags = (_f) | Fastop, .u.fastop = (_e) } #define II(_f, _e, _i) \ { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i } #define IIP(_f, _e, _i, _p) \ { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i, \ .check_perm = (_p) } #define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) } #define D2bv(_f) D((_f) | ByteOp), D(_f) #define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p) #define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e) #define I2bvIP(_f, _e, _i, _p) \ IIP((_f) | ByteOp, _e, _i, _p), IIP(_f, _e, _i, _p) #define I6ALU(_f, _e) I2bv((_f) | DstMem | SrcReg | ModRM, _e), \ I2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e), \ I2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e) static const struct opcode group7_rm1[] = { DI(SrcNone | Priv, monitor), DI(SrcNone | Priv, mwait), N, N, N, N, N, N, }; static const struct opcode group7_rm3[] = { DIP(SrcNone | Prot | Priv, vmrun, check_svme_pa), II(SrcNone | Prot | VendorSpecific, em_vmmcall, vmmcall), DIP(SrcNone | Prot | Priv, vmload, check_svme_pa), DIP(SrcNone | Prot | Priv, vmsave, check_svme_pa), DIP(SrcNone | Prot | Priv, stgi, check_svme), DIP(SrcNone | Prot | Priv, clgi, check_svme), DIP(SrcNone | Prot | Priv, skinit, check_svme), DIP(SrcNone | Prot | Priv, invlpga, check_svme), }; static const struct opcode group7_rm7[] = { N, DIP(SrcNone, rdtscp, check_rdtsc), N, N, N, N, N, N, }; static const struct opcode group1[] = { I(Lock, em_add), I(Lock | PageTable, em_or), I(Lock, em_adc), I(Lock, em_sbb), I(Lock | PageTable, em_and), I(Lock, em_sub), I(Lock, em_xor), I(0, em_cmp), }; static const struct opcode group1A[] = { I(DstMem | SrcNone | Mov | Stack, em_pop), N, N, N, N, N, N, N, }; static const struct opcode group3[] = { I(DstMem | SrcImm, em_test), I(DstMem | SrcImm, em_test), I(DstMem | SrcNone | Lock, em_not), I(DstMem | SrcNone | Lock, em_neg), I(SrcMem, em_mul_ex), I(SrcMem, em_imul_ex), I(SrcMem, em_div_ex), I(SrcMem, em_idiv_ex), }; static const struct opcode group4[] = { I(ByteOp | DstMem | SrcNone | Lock, em_grp45), I(ByteOp | DstMem | SrcNone | Lock, em_grp45), N, N, N, N, N, N, }; static const struct opcode group5[] = { I(DstMem | SrcNone | Lock, em_grp45), I(DstMem | SrcNone | Lock, em_grp45), I(SrcMem | Stack, em_grp45), I(SrcMemFAddr | ImplicitOps | Stack, em_call_far), I(SrcMem | Stack, em_grp45), I(SrcMemFAddr | ImplicitOps, em_grp45), I(SrcMem | Stack, em_grp45), N, }; static const struct opcode group6[] = { DI(Prot, sldt), DI(Prot, str), II(Prot | Priv | SrcMem16, em_lldt, lldt), II(Prot | Priv | SrcMem16, em_ltr, ltr), N, N, N, N, }; static const struct group_dual group7 = { { II(Mov | DstMem | Priv, em_sgdt, sgdt), II(Mov | DstMem | Priv, em_sidt, sidt), II(SrcMem | Priv, em_lgdt, lgdt), II(SrcMem | Priv, em_lidt, lidt), II(SrcNone | DstMem | Mov, em_smsw, smsw), N, II(SrcMem16 | Mov | Priv, em_lmsw, lmsw), II(SrcMem | ByteOp | Priv | NoAccess, em_invlpg, invlpg), }, { I(SrcNone | Priv | VendorSpecific, em_vmcall), EXT(0, group7_rm1), N, EXT(0, group7_rm3), II(SrcNone | DstMem | Mov, em_smsw, smsw), N, II(SrcMem16 | Mov | Priv, em_lmsw, lmsw), EXT(0, group7_rm7), } }; static const struct opcode group8[] = { N, N, N, N, I(DstMem | SrcImmByte, em_bt), I(DstMem | SrcImmByte | Lock | PageTable, em_bts), I(DstMem | SrcImmByte | Lock, em_btr), I(DstMem | SrcImmByte | Lock | PageTable, em_btc), }; static const struct group_dual group9 = { { N, I(DstMem64 | Lock | PageTable, em_cmpxchg8b), N, N, N, N, N, N, }, { N, N, N, N, N, N, N, N, } }; static const struct opcode group11[] = { I(DstMem | SrcImm | Mov | PageTable, em_mov), X7(D(Undefined)), }; static const struct gprefix pfx_0f_6f_0f_7f = { I(Mmx, em_mov), I(Sse | Aligned, em_mov), N, I(Sse | Unaligned, em_mov), }; static const struct gprefix pfx_vmovntpx = { I(0, em_mov), N, N, N, }; static const struct escape escape_d9 = { { N, N, N, N, N, N, N, I(DstMem, em_fnstcw), }, { /* 0xC0 - 0xC7 */ N, N, N, N, N, N, N, N, /* 0xC8 - 0xCF */ N, N, N, N, N, N, N, N, /* 0xD0 - 0xC7 */ N, N, N, N, N, N, N, N, /* 0xD8 - 0xDF */ N, N, N, N, N, N, N, N, /* 0xE0 - 0xE7 */ N, N, N, N, N, N, N, N, /* 0xE8 - 0xEF */ N, N, N, N, N, N, N, N, /* 0xF0 - 0xF7 */ N, N, N, N, N, N, N, N, /* 0xF8 - 0xFF */ N, N, N, N, N, N, N, N, } }; static const struct escape escape_db = { { N, N, N, N, N, N, N, N, }, { /* 0xC0 - 0xC7 */ N, N, N, N, N, N, N, N, /* 0xC8 - 0xCF */ N, N, N, N, N, N, N, N, /* 0xD0 - 0xC7 */ N, N, N, N, N, N, N, N, /* 0xD8 - 0xDF */ N, N, N, N, N, N, N, N, /* 0xE0 - 0xE7 */ N, N, N, I(ImplicitOps, em_fninit), N, N, N, N, /* 0xE8 - 0xEF */ N, N, N, N, N, N, N, N, /* 0xF0 - 0xF7 */ N, N, N, N, N, N, N, N, /* 0xF8 - 0xFF */ N, N, N, N, N, N, N, N, } }; static const struct escape escape_dd = { { N, N, N, N, N, N, N, I(DstMem, em_fnstsw), }, { /* 0xC0 - 0xC7 */ N, N, N, N, N, N, N, N, /* 0xC8 - 0xCF */ N, N, N, N, N, N, N, N, /* 0xD0 - 0xC7 */ N, N, N, N, N, N, N, N, /* 0xD8 - 0xDF */ N, N, N, N, N, N, N, N, /* 0xE0 - 0xE7 */ N, N, N, N, N, N, N, N, /* 0xE8 - 0xEF */ N, N, N, N, N, N, N, N, /* 0xF0 - 0xF7 */ N, N, N, N, N, N, N, N, /* 0xF8 - 0xFF */ N, N, N, N, N, N, N, N, } }; static const struct opcode opcode_table[256] = { /* 0x00 - 0x07 */ I6ALU(Lock, em_add), I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg), I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg), /* 0x08 - 0x0F */ I6ALU(Lock | PageTable, em_or), I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg), N, /* 0x10 - 0x17 */ I6ALU(Lock, em_adc), I(ImplicitOps | Stack | No64 | Src2SS, em_push_sreg), I(ImplicitOps | Stack | No64 | Src2SS, em_pop_sreg), /* 0x18 - 0x1F */ I6ALU(Lock, em_sbb), I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg), I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg), /* 0x20 - 0x27 */ I6ALU(Lock | PageTable, em_and), N, N, /* 0x28 - 0x2F */ I6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das), /* 0x30 - 0x37 */ I6ALU(Lock, em_xor), N, N, /* 0x38 - 0x3F */ I6ALU(0, em_cmp), N, N, /* 0x40 - 0x4F */ X16(D(DstReg)), /* 0x50 - 0x57 */ X8(I(SrcReg | Stack, em_push)), /* 0x58 - 0x5F */ X8(I(DstReg | Stack, em_pop)), /* 0x60 - 0x67 */ I(ImplicitOps | Stack | No64, em_pusha), I(ImplicitOps | Stack | No64, em_popa), N, D(DstReg | SrcMem32 | ModRM | Mov) /* movsxd (x86/64) */ , N, N, N, N, /* 0x68 - 0x6F */ I(SrcImm | Mov | Stack, em_push), I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op), I(SrcImmByte | Mov | Stack, em_push), I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op), I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */ I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */ /* 0x70 - 0x7F */ X16(D(SrcImmByte)), /* 0x80 - 0x87 */ G(ByteOp | DstMem | SrcImm, group1), G(DstMem | SrcImm, group1), G(ByteOp | DstMem | SrcImm | No64, group1), G(DstMem | SrcImmByte, group1), I2bv(DstMem | SrcReg | ModRM, em_test), I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_xchg), /* 0x88 - 0x8F */ I2bv(DstMem | SrcReg | ModRM | Mov | PageTable, em_mov), I2bv(DstReg | SrcMem | ModRM | Mov, em_mov), I(DstMem | SrcNone | ModRM | Mov | PageTable, em_mov_rm_sreg), D(ModRM | SrcMem | NoAccess | DstReg), I(ImplicitOps | SrcMem16 | ModRM, em_mov_sreg_rm), G(0, group1A), /* 0x90 - 0x97 */ DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)), /* 0x98 - 0x9F */ D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd), I(SrcImmFAddr | No64, em_call_far), N, II(ImplicitOps | Stack, em_pushf, pushf), II(ImplicitOps | Stack, em_popf, popf), N, I(ImplicitOps, em_lahf), /* 0xA0 - 0xA7 */ I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov), I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov), I2bv(SrcSI | DstDI | Mov | String, em_mov), I2bv(SrcSI | DstDI | String, em_cmp), /* 0xA8 - 0xAF */ I2bv(DstAcc | SrcImm, em_test), I2bv(SrcAcc | DstDI | Mov | String, em_mov), I2bv(SrcSI | DstAcc | Mov | String, em_mov), I2bv(SrcAcc | DstDI | String, em_cmp), /* 0xB0 - 0xB7 */ X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)), /* 0xB8 - 0xBF */ X8(I(DstReg | SrcImm64 | Mov, em_mov)), /* 0xC0 - 0xC7 */ D2bv(DstMem | SrcImmByte | ModRM), I(ImplicitOps | Stack | SrcImmU16, em_ret_near_imm), I(ImplicitOps | Stack, em_ret), I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg), I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg), G(ByteOp, group11), G(0, group11), /* 0xC8 - 0xCF */ I(Stack | SrcImmU16 | Src2ImmByte, em_enter), I(Stack, em_leave), N, I(ImplicitOps | Stack, em_ret_far), D(ImplicitOps), DI(SrcImmByte, intn), D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret), /* 0xD0 - 0xD7 */ D2bv(DstMem | SrcOne | ModRM), D2bv(DstMem | ModRM), N, I(DstAcc | SrcImmByte | No64, em_aad), N, N, /* 0xD8 - 0xDF */ N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N, /* 0xE0 - 0xE7 */ X3(I(SrcImmByte, em_loop)), I(SrcImmByte, em_jcxz), I2bvIP(SrcImmUByte | DstAcc, em_in, in, check_perm_in), I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out), /* 0xE8 - 0xEF */ I(SrcImm | Stack, em_call), D(SrcImm | ImplicitOps), I(SrcImmFAddr | No64, em_jmp_far), D(SrcImmByte | ImplicitOps), I2bvIP(SrcDX | DstAcc, em_in, in, check_perm_in), I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out), /* 0xF0 - 0xF7 */ N, DI(ImplicitOps, icebp), N, N, DI(ImplicitOps | Priv, hlt), D(ImplicitOps), G(ByteOp, group3), G(0, group3), /* 0xF8 - 0xFF */ D(ImplicitOps), D(ImplicitOps), I(ImplicitOps, em_cli), I(ImplicitOps, em_sti), D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5), }; static const struct opcode twobyte_table[256] = { /* 0x00 - 0x0F */ G(0, group6), GD(0, &group7), N, N, N, I(ImplicitOps | VendorSpecific, em_syscall), II(ImplicitOps | Priv, em_clts, clts), N, DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N, N, D(ImplicitOps | ModRM), N, N, /* 0x10 - 0x1F */ N, N, N, N, N, N, N, N, D(ImplicitOps | ModRM), N, N, N, N, N, N, N, /* 0x20 - 0x2F */ DIP(ModRM | DstMem | Priv | Op3264, cr_read, check_cr_read), DIP(ModRM | DstMem | Priv | Op3264, dr_read, check_dr_read), IIP(ModRM | SrcMem | Priv | Op3264, em_cr_write, cr_write, check_cr_write), IIP(ModRM | SrcMem | Priv | Op3264, em_dr_write, dr_write, check_dr_write), N, N, N, N, N, N, N, GP(ModRM | DstMem | SrcReg | Sse | Mov | Aligned, &pfx_vmovntpx), N, N, N, N, /* 0x30 - 0x3F */ II(ImplicitOps | Priv, em_wrmsr, wrmsr), IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc), II(ImplicitOps | Priv, em_rdmsr, rdmsr), IIP(ImplicitOps, em_rdpmc, rdpmc, check_rdpmc), I(ImplicitOps | VendorSpecific, em_sysenter), I(ImplicitOps | Priv | VendorSpecific, em_sysexit), N, N, N, N, N, N, N, N, N, N, /* 0x40 - 0x4F */ X16(D(DstReg | SrcMem | ModRM | Mov)), /* 0x50 - 0x5F */ N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, /* 0x60 - 0x6F */ N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, GP(SrcMem | DstReg | ModRM | Mov, &pfx_0f_6f_0f_7f), /* 0x70 - 0x7F */ N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f), /* 0x80 - 0x8F */ X16(D(SrcImm)), /* 0x90 - 0x9F */ X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)), /* 0xA0 - 0xA7 */ I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg), II(ImplicitOps, em_cpuid, cpuid), I(DstMem | SrcReg | ModRM | BitOp, em_bt), D(DstMem | SrcReg | Src2ImmByte | ModRM), D(DstMem | SrcReg | Src2CL | ModRM), N, N, /* 0xA8 - 0xAF */ I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg), DI(ImplicitOps, rsm), I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts), D(DstMem | SrcReg | Src2ImmByte | ModRM), D(DstMem | SrcReg | Src2CL | ModRM), D(ModRM), I(DstReg | SrcMem | ModRM, em_imul), /* 0xB0 - 0xB7 */ I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_cmpxchg), I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg), I(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr), I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg), I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg), D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), /* 0xB8 - 0xBF */ N, N, G(BitOp, group8), I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc), I(DstReg | SrcMem | ModRM, em_bsf), I(DstReg | SrcMem | ModRM, em_bsr), D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), /* 0xC0 - 0xC7 */ D2bv(DstMem | SrcReg | ModRM | Lock), N, D(DstMem | SrcReg | ModRM | Mov), N, N, N, GD(0, &group9), /* 0xC8 - 0xCF */ X8(I(DstReg, em_bswap)), /* 0xD0 - 0xDF */ N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, /* 0xE0 - 0xEF */ N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, /* 0xF0 - 0xFF */ N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N }; #undef D #undef N #undef G #undef GD #undef I #undef GP #undef EXT #undef D2bv #undef D2bvIP #undef I2bv #undef I2bvIP #undef I6ALU static unsigned imm_size(struct x86_emulate_ctxt *ctxt) { unsigned size; size = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; if (size == 8) size = 4; return size; } static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op, unsigned size, bool sign_extension) { int rc = X86EMUL_CONTINUE; op->type = OP_IMM; op->bytes = size; op->addr.mem.ea = ctxt->_eip; /* NB. Immediates are sign-extended as necessary. */ switch (op->bytes) { case 1: op->val = insn_fetch(s8, ctxt); break; case 2: op->val = insn_fetch(s16, ctxt); break; case 4: op->val = insn_fetch(s32, ctxt); break; case 8: op->val = insn_fetch(s64, ctxt); break; } if (!sign_extension) { switch (op->bytes) { case 1: op->val &= 0xff; break; case 2: op->val &= 0xffff; break; case 4: op->val &= 0xffffffff; break; } } done: return rc; } static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, unsigned d) { int rc = X86EMUL_CONTINUE; switch (d) { case OpReg: decode_register_operand(ctxt, op); break; case OpImmUByte: rc = decode_imm(ctxt, op, 1, false); break; case OpMem: ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; mem_common: *op = ctxt->memop; ctxt->memopp = op; if ((ctxt->d & BitOp) && op == &ctxt->dst) fetch_bit_operand(ctxt); op->orig_val = op->val; break; case OpMem64: ctxt->memop.bytes = 8; goto mem_common; case OpAcc: op->type = OP_REG; op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); fetch_register_operand(op); op->orig_val = op->val; break; case OpDI: op->type = OP_MEM; op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; op->addr.mem.ea = register_address(ctxt, reg_read(ctxt, VCPU_REGS_RDI)); op->addr.mem.seg = VCPU_SREG_ES; op->val = 0; op->count = 1; break; case OpDX: op->type = OP_REG; op->bytes = 2; op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); fetch_register_operand(op); break; case OpCL: op->bytes = 1; op->val = reg_read(ctxt, VCPU_REGS_RCX) & 0xff; break; case OpImmByte: rc = decode_imm(ctxt, op, 1, true); break; case OpOne: op->bytes = 1; op->val = 1; break; case OpImm: rc = decode_imm(ctxt, op, imm_size(ctxt), true); break; case OpImm64: rc = decode_imm(ctxt, op, ctxt->op_bytes, true); break; case OpMem8: ctxt->memop.bytes = 1; goto mem_common; case OpMem16: ctxt->memop.bytes = 2; goto mem_common; case OpMem32: ctxt->memop.bytes = 4; goto mem_common; case OpImmU16: rc = decode_imm(ctxt, op, 2, false); break; case OpImmU: rc = decode_imm(ctxt, op, imm_size(ctxt), false); break; case OpSI: op->type = OP_MEM; op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; op->addr.mem.ea = register_address(ctxt, reg_read(ctxt, VCPU_REGS_RSI)); op->addr.mem.seg = seg_override(ctxt); op->val = 0; op->count = 1; break; case OpImmFAddr: op->type = OP_IMM; op->addr.mem.ea = ctxt->_eip; op->bytes = ctxt->op_bytes + 2; insn_fetch_arr(op->valptr, op->bytes, ctxt); break; case OpMemFAddr: ctxt->memop.bytes = ctxt->op_bytes + 2; goto mem_common; case OpES: op->val = VCPU_SREG_ES; break; case OpCS: op->val = VCPU_SREG_CS; break; case OpSS: op->val = VCPU_SREG_SS; break; case OpDS: op->val = VCPU_SREG_DS; break; case OpFS: op->val = VCPU_SREG_FS; break; case OpGS: op->val = VCPU_SREG_GS; break; case OpImplicit: /* Special instructions do their own operand decoding. */ default: op->type = OP_NONE; /* Disable writeback. */ break; } done: return rc; } int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) { int rc = X86EMUL_CONTINUE; int mode = ctxt->mode; int def_op_bytes, def_ad_bytes, goffset, simd_prefix; bool op_prefix = false; struct opcode opcode; ctxt->memop.type = OP_NONE; ctxt->memopp = NULL; ctxt->_eip = ctxt->eip; ctxt->fetch.start = ctxt->_eip; ctxt->fetch.end = ctxt->fetch.start + insn_len; if (insn_len > 0) memcpy(ctxt->fetch.data, insn, insn_len); switch (mode) { case X86EMUL_MODE_REAL: case X86EMUL_MODE_VM86: case X86EMUL_MODE_PROT16: def_op_bytes = def_ad_bytes = 2; break; case X86EMUL_MODE_PROT32: def_op_bytes = def_ad_bytes = 4; break; #ifdef CONFIG_X86_64 case X86EMUL_MODE_PROT64: def_op_bytes = 4; def_ad_bytes = 8; break; #endif default: return EMULATION_FAILED; } ctxt->op_bytes = def_op_bytes; ctxt->ad_bytes = def_ad_bytes; /* Legacy prefixes. */ for (;;) { switch (ctxt->b = insn_fetch(u8, ctxt)) { case 0x66: /* operand-size override */ op_prefix = true; /* switch between 2/4 bytes */ ctxt->op_bytes = def_op_bytes ^ 6; break; case 0x67: /* address-size override */ if (mode == X86EMUL_MODE_PROT64) /* switch between 4/8 bytes */ ctxt->ad_bytes = def_ad_bytes ^ 12; else /* switch between 2/4 bytes */ ctxt->ad_bytes = def_ad_bytes ^ 6; break; case 0x26: /* ES override */ case 0x2e: /* CS override */ case 0x36: /* SS override */ case 0x3e: /* DS override */ set_seg_override(ctxt, (ctxt->b >> 3) & 3); break; case 0x64: /* FS override */ case 0x65: /* GS override */ set_seg_override(ctxt, ctxt->b & 7); break; case 0x40 ... 0x4f: /* REX */ if (mode != X86EMUL_MODE_PROT64) goto done_prefixes; ctxt->rex_prefix = ctxt->b; continue; case 0xf0: /* LOCK */ ctxt->lock_prefix = 1; break; case 0xf2: /* REPNE/REPNZ */ case 0xf3: /* REP/REPE/REPZ */ ctxt->rep_prefix = ctxt->b; break; default: goto done_prefixes; } /* Any legacy prefix after a REX prefix nullifies its effect. */ ctxt->rex_prefix = 0; } done_prefixes: /* REX prefix. */ if (ctxt->rex_prefix & 8) ctxt->op_bytes = 8; /* REX.W */ /* Opcode byte(s). */ opcode = opcode_table[ctxt->b]; /* Two-byte opcode? */ if (ctxt->b == 0x0f) { ctxt->twobyte = 1; ctxt->b = insn_fetch(u8, ctxt); opcode = twobyte_table[ctxt->b]; } ctxt->d = opcode.flags; if (ctxt->d & ModRM) ctxt->modrm = insn_fetch(u8, ctxt); while (ctxt->d & GroupMask) { switch (ctxt->d & GroupMask) { case Group: goffset = (ctxt->modrm >> 3) & 7; opcode = opcode.u.group[goffset]; break; case GroupDual: goffset = (ctxt->modrm >> 3) & 7; if ((ctxt->modrm >> 6) == 3) opcode = opcode.u.gdual->mod3[goffset]; else opcode = opcode.u.gdual->mod012[goffset]; break; case RMExt: goffset = ctxt->modrm & 7; opcode = opcode.u.group[goffset]; break; case Prefix: if (ctxt->rep_prefix && op_prefix) return EMULATION_FAILED; simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix; switch (simd_prefix) { case 0x00: opcode = opcode.u.gprefix->pfx_no; break; case 0x66: opcode = opcode.u.gprefix->pfx_66; break; case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break; case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break; } break; case Escape: if (ctxt->modrm > 0xbf) opcode = opcode.u.esc->high[ctxt->modrm - 0xc0]; else opcode = opcode.u.esc->op[(ctxt->modrm >> 3) & 7]; break; default: return EMULATION_FAILED; } ctxt->d &= ~(u64)GroupMask; ctxt->d |= opcode.flags; } ctxt->execute = opcode.u.execute; ctxt->check_perm = opcode.check_perm; ctxt->intercept = opcode.intercept; /* Unrecognised? */ if (ctxt->d == 0 || (ctxt->d & Undefined)) return EMULATION_FAILED; if (!(ctxt->d & VendorSpecific) && ctxt->only_vendor_specific_insn) return EMULATION_FAILED; if (mode == X86EMUL_MODE_PROT64 && (ctxt->d & Stack)) ctxt->op_bytes = 8; if (ctxt->d & Op3264) { if (mode == X86EMUL_MODE_PROT64) ctxt->op_bytes = 8; else ctxt->op_bytes = 4; } if (ctxt->d & Sse) ctxt->op_bytes = 16; else if (ctxt->d & Mmx) ctxt->op_bytes = 8; /* ModRM and SIB bytes. */ if (ctxt->d & ModRM) { rc = decode_modrm(ctxt, &ctxt->memop); if (!ctxt->has_seg_override) set_seg_override(ctxt, ctxt->modrm_seg); } else if (ctxt->d & MemAbs) rc = decode_abs(ctxt, &ctxt->memop); if (rc != X86EMUL_CONTINUE) goto done; if (!ctxt->has_seg_override) set_seg_override(ctxt, VCPU_SREG_DS); ctxt->memop.addr.mem.seg = seg_override(ctxt); if (ctxt->memop.type == OP_MEM && ctxt->ad_bytes != 8) ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea; /* * Decode and fetch the source operand: register, memory * or immediate. */ rc = decode_operand(ctxt, &ctxt->src, (ctxt->d >> SrcShift) & OpMask); if (rc != X86EMUL_CONTINUE) goto done; /* * Decode and fetch the second source operand: register, memory * or immediate. */ rc = decode_operand(ctxt, &ctxt->src2, (ctxt->d >> Src2Shift) & OpMask); if (rc != X86EMUL_CONTINUE) goto done; /* Decode and fetch the destination operand: register or memory. */ rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask); done: if (ctxt->memopp && ctxt->memopp->type == OP_MEM && ctxt->rip_relative) ctxt->memopp->addr.mem.ea += ctxt->_eip; return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK; } bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt) { return ctxt->d & PageTable; } static bool string_insn_completed(struct x86_emulate_ctxt *ctxt) { /* The second termination condition only applies for REPE * and REPNE. Test if the repeat string operation prefix is * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the * corresponding termination condition according to: * - if REPE/REPZ and ZF = 0 then done * - if REPNE/REPNZ and ZF = 1 then done */ if (((ctxt->b == 0xa6) || (ctxt->b == 0xa7) || (ctxt->b == 0xae) || (ctxt->b == 0xaf)) && (((ctxt->rep_prefix == REPE_PREFIX) && ((ctxt->eflags & EFLG_ZF) == 0)) || ((ctxt->rep_prefix == REPNE_PREFIX) && ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)))) return true; return false; } static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt) { bool fault = false; ctxt->ops->get_fpu(ctxt); asm volatile("1: fwait \n\t" "2: \n\t" ".pushsection .fixup,\"ax\" \n\t" "3: \n\t" "movb $1, %[fault] \n\t" "jmp 2b \n\t" ".popsection \n\t" _ASM_EXTABLE(1b, 3b) : [fault]"+qm"(fault)); ctxt->ops->put_fpu(ctxt); if (unlikely(fault)) return emulate_exception(ctxt, MF_VECTOR, 0, false); return X86EMUL_CONTINUE; } static void fetch_possible_mmx_operand(struct x86_emulate_ctxt *ctxt, struct operand *op) { if (op->type == OP_MM) read_mmx_reg(ctxt, &op->mm_val, op->addr.mm); } static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *)) { ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF; fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE; asm("push %[flags]; popf; call *%[fastop]; pushf; pop %[flags]\n" : "+a"(ctxt->dst.val), "+b"(ctxt->src.val), [flags]"+D"(flags) : "c"(ctxt->src2.val), [fastop]"S"(fop)); ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK); return X86EMUL_CONTINUE; } int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) { const struct x86_emulate_ops *ops = ctxt->ops; int rc = X86EMUL_CONTINUE; int saved_dst_type = ctxt->dst.type; ctxt->mem_read.pos = 0; if (ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) { rc = emulate_ud(ctxt); goto done; } /* LOCK prefix is allowed only with some instructions */ if (ctxt->lock_prefix && (!(ctxt->d & Lock) || ctxt->dst.type != OP_MEM)) { rc = emulate_ud(ctxt); goto done; } if ((ctxt->d & SrcMask) == SrcMemFAddr && ctxt->src.type != OP_MEM) { rc = emulate_ud(ctxt); goto done; } if (((ctxt->d & (Sse|Mmx)) && ((ops->get_cr(ctxt, 0) & X86_CR0_EM))) || ((ctxt->d & Sse) && !(ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR))) { rc = emulate_ud(ctxt); goto done; } if ((ctxt->d & (Sse|Mmx)) && (ops->get_cr(ctxt, 0) & X86_CR0_TS)) { rc = emulate_nm(ctxt); goto done; } if (ctxt->d & Mmx) { rc = flush_pending_x87_faults(ctxt); if (rc != X86EMUL_CONTINUE) goto done; /* * Now that we know the fpu is exception safe, we can fetch * operands from it. */ fetch_possible_mmx_operand(ctxt, &ctxt->src); fetch_possible_mmx_operand(ctxt, &ctxt->src2); if (!(ctxt->d & Mov)) fetch_possible_mmx_operand(ctxt, &ctxt->dst); } if (unlikely(ctxt->guest_mode) && ctxt->intercept) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_PRE_EXCEPT); if (rc != X86EMUL_CONTINUE) goto done; } /* Privileged instruction can be executed only in CPL=0 */ if ((ctxt->d & Priv) && ops->cpl(ctxt)) { rc = emulate_gp(ctxt, 0); goto done; } /* Instruction can only be executed in protected mode */ if ((ctxt->d & Prot) && ctxt->mode < X86EMUL_MODE_PROT16) { rc = emulate_ud(ctxt); goto done; } /* Do instruction specific permission checks */ if (ctxt->check_perm) { rc = ctxt->check_perm(ctxt); if (rc != X86EMUL_CONTINUE) goto done; } if (unlikely(ctxt->guest_mode) && ctxt->intercept) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_POST_EXCEPT); if (rc != X86EMUL_CONTINUE) goto done; } if (ctxt->rep_prefix && (ctxt->d & String)) { /* All REP prefixes have the same first termination condition */ if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) { ctxt->eip = ctxt->_eip; goto done; } } if ((ctxt->src.type == OP_MEM) && !(ctxt->d & NoAccess)) { rc = segmented_read(ctxt, ctxt->src.addr.mem, ctxt->src.valptr, ctxt->src.bytes); if (rc != X86EMUL_CONTINUE) goto done; ctxt->src.orig_val64 = ctxt->src.val64; } if (ctxt->src2.type == OP_MEM) { rc = segmented_read(ctxt, ctxt->src2.addr.mem, &ctxt->src2.val, ctxt->src2.bytes); if (rc != X86EMUL_CONTINUE) goto done; } if ((ctxt->d & DstMask) == ImplicitOps) goto special_insn; if ((ctxt->dst.type == OP_MEM) && !(ctxt->d & Mov)) { /* optimisation - avoid slow emulated read if Mov */ rc = segmented_read(ctxt, ctxt->dst.addr.mem, &ctxt->dst.val, ctxt->dst.bytes); if (rc != X86EMUL_CONTINUE) goto done; } ctxt->dst.orig_val = ctxt->dst.val; special_insn: if (unlikely(ctxt->guest_mode) && ctxt->intercept) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_POST_MEMACCESS); if (rc != X86EMUL_CONTINUE) goto done; } if (ctxt->execute) { if (ctxt->d & Fastop) { void (*fop)(struct fastop *) = (void *)ctxt->execute; rc = fastop(ctxt, fop); if (rc != X86EMUL_CONTINUE) goto done; goto writeback; } rc = ctxt->execute(ctxt); if (rc != X86EMUL_CONTINUE) goto done; goto writeback; } if (ctxt->twobyte) goto twobyte_insn; switch (ctxt->b) { case 0x40 ... 0x47: /* inc r16/r32 */ emulate_1op(ctxt, "inc"); break; case 0x48 ... 0x4f: /* dec r16/r32 */ emulate_1op(ctxt, "dec"); break; case 0x63: /* movsxd */ if (ctxt->mode != X86EMUL_MODE_PROT64) goto cannot_emulate; ctxt->dst.val = (s32) ctxt->src.val; break; case 0x70 ... 0x7f: /* jcc (short) */ if (test_cc(ctxt->b, ctxt->eflags)) jmp_rel(ctxt, ctxt->src.val); break; case 0x8d: /* lea r16/r32, m */ ctxt->dst.val = ctxt->src.addr.mem.ea; break; case 0x90 ... 0x97: /* nop / xchg reg, rax */ if (ctxt->dst.addr.reg == reg_rmw(ctxt, VCPU_REGS_RAX)) break; rc = em_xchg(ctxt); break; case 0x98: /* cbw/cwde/cdqe */ switch (ctxt->op_bytes) { case 2: ctxt->dst.val = (s8)ctxt->dst.val; break; case 4: ctxt->dst.val = (s16)ctxt->dst.val; break; case 8: ctxt->dst.val = (s32)ctxt->dst.val; break; } break; case 0xc0 ... 0xc1: rc = em_grp2(ctxt); break; case 0xcc: /* int3 */ rc = emulate_int(ctxt, 3); break; case 0xcd: /* int n */ rc = emulate_int(ctxt, ctxt->src.val); break; case 0xce: /* into */ if (ctxt->eflags & EFLG_OF) rc = emulate_int(ctxt, 4); break; case 0xd0 ... 0xd1: /* Grp2 */ rc = em_grp2(ctxt); break; case 0xd2 ... 0xd3: /* Grp2 */ ctxt->src.val = reg_read(ctxt, VCPU_REGS_RCX); rc = em_grp2(ctxt); break; case 0xe9: /* jmp rel */ case 0xeb: /* jmp rel short */ jmp_rel(ctxt, ctxt->src.val); ctxt->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xf4: /* hlt */ ctxt->ops->halt(ctxt); break; case 0xf5: /* cmc */ /* complement carry flag from eflags reg */ ctxt->eflags ^= EFLG_CF; break; case 0xf8: /* clc */ ctxt->eflags &= ~EFLG_CF; break; case 0xf9: /* stc */ ctxt->eflags |= EFLG_CF; break; case 0xfc: /* cld */ ctxt->eflags &= ~EFLG_DF; break; case 0xfd: /* std */ ctxt->eflags |= EFLG_DF; break; default: goto cannot_emulate; } if (rc != X86EMUL_CONTINUE) goto done; writeback: rc = writeback(ctxt); if (rc != X86EMUL_CONTINUE) goto done; /* * restore dst type in case the decoding will be reused * (happens for string instruction ) */ ctxt->dst.type = saved_dst_type; if ((ctxt->d & SrcMask) == SrcSI) string_addr_inc(ctxt, VCPU_REGS_RSI, &ctxt->src); if ((ctxt->d & DstMask) == DstDI) string_addr_inc(ctxt, VCPU_REGS_RDI, &ctxt->dst); if (ctxt->rep_prefix && (ctxt->d & String)) { unsigned int count; struct read_cache *r = &ctxt->io_read; if ((ctxt->d & SrcMask) == SrcSI) count = ctxt->src.count; else count = ctxt->dst.count; register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RCX), -count); if (!string_insn_completed(ctxt)) { /* * Re-enter guest when pio read ahead buffer is empty * or, if it is not used, after each 1024 iteration. */ if ((r->end != 0 || reg_read(ctxt, VCPU_REGS_RCX) & 0x3ff) && (r->end == 0 || r->end != r->pos)) { /* * Reset read cache. Usually happens before * decode, but since instruction is restarted * we have to do it here. */ ctxt->mem_read.end = 0; writeback_registers(ctxt); return EMULATION_RESTART; } goto done; /* skip rip writeback */ } } ctxt->eip = ctxt->_eip; done: if (rc == X86EMUL_PROPAGATE_FAULT) ctxt->have_exception = true; if (rc == X86EMUL_INTERCEPTED) return EMULATION_INTERCEPTED; if (rc == X86EMUL_CONTINUE) writeback_registers(ctxt); return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; twobyte_insn: switch (ctxt->b) { case 0x09: /* wbinvd */ (ctxt->ops->wbinvd)(ctxt); break; case 0x08: /* invd */ case 0x0d: /* GrpP (prefetch) */ case 0x18: /* Grp16 (prefetch/nop) */ break; case 0x20: /* mov cr, reg */ ctxt->dst.val = ops->get_cr(ctxt, ctxt->modrm_reg); break; case 0x21: /* mov from dr to reg */ ops->get_dr(ctxt, ctxt->modrm_reg, &ctxt->dst.val); break; case 0x40 ... 0x4f: /* cmov */ ctxt->dst.val = ctxt->dst.orig_val = ctxt->src.val; if (!test_cc(ctxt->b, ctxt->eflags)) ctxt->dst.type = OP_NONE; /* no writeback */ break; case 0x80 ... 0x8f: /* jnz rel, etc*/ if (test_cc(ctxt->b, ctxt->eflags)) jmp_rel(ctxt, ctxt->src.val); break; case 0x90 ... 0x9f: /* setcc r/m8 */ ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags); break; case 0xa4: /* shld imm8, r, r/m */ case 0xa5: /* shld cl, r, r/m */ emulate_2op_cl(ctxt, "shld"); break; case 0xac: /* shrd imm8, r, r/m */ case 0xad: /* shrd cl, r, r/m */ emulate_2op_cl(ctxt, "shrd"); break; case 0xae: /* clflush */ break; case 0xb6 ... 0xb7: /* movzx */ ctxt->dst.bytes = ctxt->op_bytes; ctxt->dst.val = (ctxt->src.bytes == 1) ? (u8) ctxt->src.val : (u16) ctxt->src.val; break; case 0xbe ... 0xbf: /* movsx */ ctxt->dst.bytes = ctxt->op_bytes; ctxt->dst.val = (ctxt->src.bytes == 1) ? (s8) ctxt->src.val : (s16) ctxt->src.val; break; case 0xc0 ... 0xc1: /* xadd */ emulate_2op_SrcV(ctxt, "add"); /* Write back the register source. */ ctxt->src.val = ctxt->dst.orig_val; write_register_operand(&ctxt->src); break; case 0xc3: /* movnti */ ctxt->dst.bytes = ctxt->op_bytes; ctxt->dst.val = (ctxt->op_bytes == 4) ? (u32) ctxt->src.val : (u64) ctxt->src.val; break; default: goto cannot_emulate; } if (rc != X86EMUL_CONTINUE) goto done; goto writeback; cannot_emulate: return EMULATION_FAILED; } void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt) { invalidate_registers(ctxt); } void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt) { writeback_registers(ctxt); }