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Diffstat (limited to 'arch/x86/kvm/x86_emulate.c')
-rw-r--r-- | arch/x86/kvm/x86_emulate.c | 1912 |
1 files changed, 1912 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c new file mode 100644 index 0000000..7958600 --- /dev/null +++ b/arch/x86/kvm/x86_emulate.c @@ -0,0 +1,1912 @@ +/****************************************************************************** + * x86_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 + * + * Avi Kivity <avi@qumranet.com> + * Yaniv Kamay <yaniv@qumranet.com> + * + * 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 + */ + +#ifndef __KERNEL__ +#include <stdio.h> +#include <stdint.h> +#include <public/xen.h> +#define DPRINTF(_f, _a ...) printf(_f , ## _a) +#else +#include <linux/kvm_host.h> +#define DPRINTF(x...) do {} while (0) +#endif +#include <linux/module.h> +#include <asm/kvm_x86_emulate.h> + +/* + * 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 <imm>,<reg>' need + * not be handled. + */ + +/* Operand sizes: 8-bit operands or specified/overridden size. */ +#define ByteOp (1<<0) /* 8-bit operands. */ +/* Destination operand type. */ +#define ImplicitOps (1<<1) /* Implicit in opcode. No generic decode. */ +#define DstReg (2<<1) /* Register operand. */ +#define DstMem (3<<1) /* Memory operand. */ +#define DstMask (3<<1) +/* Source operand type. */ +#define SrcNone (0<<3) /* No source operand. */ +#define SrcImplicit (0<<3) /* Source operand is implicit in the opcode. */ +#define SrcReg (1<<3) /* Register operand. */ +#define SrcMem (2<<3) /* Memory operand. */ +#define SrcMem16 (3<<3) /* Memory operand (16-bit). */ +#define SrcMem32 (4<<3) /* Memory operand (32-bit). */ +#define SrcImm (5<<3) /* Immediate operand. */ +#define SrcImmByte (6<<3) /* 8-bit sign-extended immediate operand. */ +#define SrcMask (7<<3) +/* Generic ModRM decode. */ +#define ModRM (1<<6) +/* Destination is only written; never read. */ +#define Mov (1<<7) +#define BitOp (1<<8) +#define MemAbs (1<<9) /* Memory operand is absolute displacement */ +#define String (1<<10) /* String instruction (rep capable) */ +#define Stack (1<<11) /* Stack instruction (push/pop) */ + +static u16 opcode_table[256] = { + /* 0x00 - 0x07 */ + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, + ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, + 0, 0, 0, 0, + /* 0x08 - 0x0F */ + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, + ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, + 0, 0, 0, 0, + /* 0x10 - 0x17 */ + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, + ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, + 0, 0, 0, 0, + /* 0x18 - 0x1F */ + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, + ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, + 0, 0, 0, 0, + /* 0x20 - 0x27 */ + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, + ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, + SrcImmByte, SrcImm, 0, 0, + /* 0x28 - 0x2F */ + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, + ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, + 0, 0, 0, 0, + /* 0x30 - 0x37 */ + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, + ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, + 0, 0, 0, 0, + /* 0x38 - 0x3F */ + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, + ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, + 0, 0, 0, 0, + /* 0x40 - 0x47 */ + DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, + /* 0x48 - 0x4F */ + DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, + /* 0x50 - 0x57 */ + SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, + SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, + /* 0x58 - 0x5F */ + DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack, + DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack, + /* 0x60 - 0x67 */ + 0, 0, 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ , + 0, 0, 0, 0, + /* 0x68 - 0x6F */ + 0, 0, ImplicitOps | Mov | Stack, 0, + SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps, /* insb, insw/insd */ + SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps, /* outsb, outsw/outsd */ + /* 0x70 - 0x77 */ + ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + /* 0x78 - 0x7F */ + ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + /* 0x80 - 0x87 */ + ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM, + ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImmByte | ModRM, + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, + /* 0x88 - 0x8F */ + ByteOp | DstMem | SrcReg | ModRM | Mov, DstMem | SrcReg | ModRM | Mov, + ByteOp | DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, + 0, ModRM | DstReg, 0, DstMem | SrcNone | ModRM | Mov | Stack, + /* 0x90 - 0x9F */ + 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, ImplicitOps | Stack, ImplicitOps | Stack, 0, 0, + /* 0xA0 - 0xA7 */ + ByteOp | DstReg | SrcMem | Mov | MemAbs, DstReg | SrcMem | Mov | MemAbs, + ByteOp | DstMem | SrcReg | Mov | MemAbs, DstMem | SrcReg | Mov | MemAbs, + ByteOp | ImplicitOps | Mov | String, ImplicitOps | Mov | String, + ByteOp | ImplicitOps | String, ImplicitOps | String, + /* 0xA8 - 0xAF */ + 0, 0, ByteOp | ImplicitOps | Mov | String, ImplicitOps | Mov | String, + ByteOp | ImplicitOps | Mov | String, ImplicitOps | Mov | String, + ByteOp | ImplicitOps | String, ImplicitOps | String, + /* 0xB0 - 0xBF */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0xC0 - 0xC7 */ + ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImmByte | ModRM, + 0, ImplicitOps | Stack, 0, 0, + ByteOp | DstMem | SrcImm | ModRM | Mov, DstMem | SrcImm | ModRM | Mov, + /* 0xC8 - 0xCF */ + 0, 0, 0, 0, 0, 0, 0, 0, + /* 0xD0 - 0xD7 */ + ByteOp | DstMem | SrcImplicit | ModRM, DstMem | SrcImplicit | ModRM, + ByteOp | DstMem | SrcImplicit | ModRM, DstMem | SrcImplicit | ModRM, + 0, 0, 0, 0, + /* 0xD8 - 0xDF */ + 0, 0, 0, 0, 0, 0, 0, 0, + /* 0xE0 - 0xE7 */ + 0, 0, 0, 0, 0, 0, 0, 0, + /* 0xE8 - 0xEF */ + ImplicitOps | Stack, SrcImm|ImplicitOps, 0, SrcImmByte|ImplicitOps, + 0, 0, 0, 0, + /* 0xF0 - 0xF7 */ + 0, 0, 0, 0, + ImplicitOps, ImplicitOps, + ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM, + /* 0xF8 - 0xFF */ + ImplicitOps, 0, ImplicitOps, ImplicitOps, + 0, 0, ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM +}; + +static u16 twobyte_table[256] = { + /* 0x00 - 0x0F */ + 0, SrcMem | ModRM | DstReg, 0, 0, 0, 0, ImplicitOps, 0, + ImplicitOps, ImplicitOps, 0, 0, 0, ImplicitOps | ModRM, 0, 0, + /* 0x10 - 0x1F */ + 0, 0, 0, 0, 0, 0, 0, 0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0, 0, + /* 0x20 - 0x2F */ + ModRM | ImplicitOps, ModRM, ModRM | ImplicitOps, ModRM, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, + /* 0x30 - 0x3F */ + ImplicitOps, 0, ImplicitOps, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0x40 - 0x47 */ + DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, + DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, + DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, + DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, + /* 0x48 - 0x4F */ + DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, + DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, + DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, + DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, + /* 0x50 - 0x5F */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0x60 - 0x6F */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0x70 - 0x7F */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0x80 - 0x8F */ + ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + /* 0x90 - 0x9F */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0xA0 - 0xA7 */ + 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, 0, 0, + /* 0xA8 - 0xAF */ + 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, 0, 0, + /* 0xB0 - 0xB7 */ + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, 0, + DstMem | SrcReg | ModRM | BitOp, + 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov, + DstReg | SrcMem16 | ModRM | Mov, + /* 0xB8 - 0xBF */ + 0, 0, DstMem | SrcImmByte | ModRM, DstMem | SrcReg | ModRM | BitOp, + 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov, + DstReg | SrcMem16 | ModRM | Mov, + /* 0xC0 - 0xCF */ + 0, 0, 0, DstMem | SrcReg | ModRM | Mov, 0, 0, 0, ImplicitOps | ModRM, + 0, 0, 0, 0, 0, 0, 0, 0, + /* 0xD0 - 0xDF */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0xE0 - 0xEF */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0xF0 - 0xFF */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 +}; + +/* EFLAGS bit definitions. */ +#define EFLG_OF (1<<11) +#define EFLG_DF (1<<10) +#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) + +/* + * 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"; " + +/* Raw emulation: instruction has two explicit operands. */ +#define __emulate_2op_nobyte(_op,_src,_dst,_eflags,_wx,_wy,_lx,_ly,_qx,_qy) \ + do { \ + unsigned long _tmp; \ + \ + switch ((_dst).bytes) { \ + case 2: \ + __asm__ __volatile__ ( \ + _PRE_EFLAGS("0", "4", "2") \ + _op"w %"_wx"3,%1; " \ + _POST_EFLAGS("0", "4", "2") \ + : "=m" (_eflags), "=m" ((_dst).val), \ + "=&r" (_tmp) \ + : _wy ((_src).val), "i" (EFLAGS_MASK)); \ + break; \ + case 4: \ + __asm__ __volatile__ ( \ + _PRE_EFLAGS("0", "4", "2") \ + _op"l %"_lx"3,%1; " \ + _POST_EFLAGS("0", "4", "2") \ + : "=m" (_eflags), "=m" ((_dst).val), \ + "=&r" (_tmp) \ + : _ly ((_src).val), "i" (EFLAGS_MASK)); \ + break; \ + case 8: \ + __emulate_2op_8byte(_op, _src, _dst, \ + _eflags, _qx, _qy); \ + break; \ + } \ + } while (0) + +#define __emulate_2op(_op,_src,_dst,_eflags,_bx,_by,_wx,_wy,_lx,_ly,_qx,_qy) \ + do { \ + unsigned long _tmp; \ + switch ((_dst).bytes) { \ + case 1: \ + __asm__ __volatile__ ( \ + _PRE_EFLAGS("0", "4", "2") \ + _op"b %"_bx"3,%1; " \ + _POST_EFLAGS("0", "4", "2") \ + : "=m" (_eflags), "=m" ((_dst).val), \ + "=&r" (_tmp) \ + : _by ((_src).val), "i" (EFLAGS_MASK)); \ + break; \ + default: \ + __emulate_2op_nobyte(_op, _src, _dst, _eflags, \ + _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(_op, _src, _dst, _eflags) \ + __emulate_2op(_op, _src, _dst, _eflags, \ + "b", "c", "b", "c", "b", "c", "b", "c") + +/* Source operand is byte, word, long or quad sized. */ +#define emulate_2op_SrcV(_op, _src, _dst, _eflags) \ + __emulate_2op(_op, _src, _dst, _eflags, \ + "b", "q", "w", "r", _LO32, "r", "", "r") + +/* Source operand is word, long or quad sized. */ +#define emulate_2op_SrcV_nobyte(_op, _src, _dst, _eflags) \ + __emulate_2op_nobyte(_op, _src, _dst, _eflags, \ + "w", "r", _LO32, "r", "", "r") + +/* Instruction has only one explicit operand (no source operand). */ +#define emulate_1op(_op, _dst, _eflags) \ + do { \ + unsigned long _tmp; \ + \ + switch ((_dst).bytes) { \ + case 1: \ + __asm__ __volatile__ ( \ + _PRE_EFLAGS("0", "3", "2") \ + _op"b %1; " \ + _POST_EFLAGS("0", "3", "2") \ + : "=m" (_eflags), "=m" ((_dst).val), \ + "=&r" (_tmp) \ + : "i" (EFLAGS_MASK)); \ + break; \ + case 2: \ + __asm__ __volatile__ ( \ + _PRE_EFLAGS("0", "3", "2") \ + _op"w %1; " \ + _POST_EFLAGS("0", "3", "2") \ + : "=m" (_eflags), "=m" ((_dst).val), \ + "=&r" (_tmp) \ + : "i" (EFLAGS_MASK)); \ + break; \ + case 4: \ + __asm__ __volatile__ ( \ + _PRE_EFLAGS("0", "3", "2") \ + _op"l %1; " \ + _POST_EFLAGS("0", "3", "2") \ + : "=m" (_eflags), "=m" ((_dst).val), \ + "=&r" (_tmp) \ + : "i" (EFLAGS_MASK)); \ + break; \ + case 8: \ + __emulate_1op_8byte(_op, _dst, _eflags); \ + break; \ + } \ + } while (0) + +/* Emulate an instruction with quadword operands (x86/64 only). */ +#if defined(CONFIG_X86_64) +#define __emulate_2op_8byte(_op, _src, _dst, _eflags, _qx, _qy) \ + do { \ + __asm__ __volatile__ ( \ + _PRE_EFLAGS("0", "4", "2") \ + _op"q %"_qx"3,%1; " \ + _POST_EFLAGS("0", "4", "2") \ + : "=m" (_eflags), "=m" ((_dst).val), "=&r" (_tmp) \ + : _qy ((_src).val), "i" (EFLAGS_MASK)); \ + } while (0) + +#define __emulate_1op_8byte(_op, _dst, _eflags) \ + do { \ + __asm__ __volatile__ ( \ + _PRE_EFLAGS("0", "3", "2") \ + _op"q %1; " \ + _POST_EFLAGS("0", "3", "2") \ + : "=m" (_eflags), "=m" ((_dst).val), "=&r" (_tmp) \ + : "i" (EFLAGS_MASK)); \ + } while (0) + +#elif defined(__i386__) +#define __emulate_2op_8byte(_op, _src, _dst, _eflags, _qx, _qy) +#define __emulate_1op_8byte(_op, _dst, _eflags) +#endif /* __i386__ */ + +/* Fetch next part of the instruction being emulated. */ +#define insn_fetch(_type, _size, _eip) \ +({ unsigned long _x; \ + rc = do_insn_fetch(ctxt, ops, (_eip), &_x, (_size)); \ + if (rc != 0) \ + goto done; \ + (_eip) += (_size); \ + (_type)_x; \ +}) + +/* Access/update address held in a register, based on addressing mode. */ +#define address_mask(reg) \ + ((c->ad_bytes == sizeof(unsigned long)) ? \ + (reg) : ((reg) & ((1UL << (c->ad_bytes << 3)) - 1))) +#define register_address(base, reg) \ + ((base) + address_mask(reg)) +#define register_address_increment(reg, inc) \ + do { \ + /* signed type ensures sign extension to long */ \ + int _inc = (inc); \ + if (c->ad_bytes == sizeof(unsigned long)) \ + (reg) += _inc; \ + else \ + (reg) = ((reg) & \ + ~((1UL << (c->ad_bytes << 3)) - 1)) | \ + (((reg) + _inc) & \ + ((1UL << (c->ad_bytes << 3)) - 1)); \ + } while (0) + +#define JMP_REL(rel) \ + do { \ + register_address_increment(c->eip, rel); \ + } while (0) + +static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops, + unsigned long linear, u8 *dest) +{ + struct fetch_cache *fc = &ctxt->decode.fetch; + int rc; + int size; + + if (linear < fc->start || linear >= fc->end) { + size = min(15UL, PAGE_SIZE - offset_in_page(linear)); + rc = ops->read_std(linear, fc->data, size, ctxt->vcpu); + if (rc) + return rc; + fc->start = linear; + fc->end = linear + size; + } + *dest = fc->data[linear - fc->start]; + return 0; +} + +static int do_insn_fetch(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops, + unsigned long eip, void *dest, unsigned size) +{ + int rc = 0; + + eip += ctxt->cs_base; + while (size--) { + rc = do_fetch_insn_byte(ctxt, ops, eip++, dest++); + if (rc) + return rc; + } + return 0; +} + +/* + * 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(u8 modrm_reg, unsigned long *regs, + int highbyte_regs) +{ + void *p; + + p = ®s[modrm_reg]; + if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8) + p = (unsigned char *)®s[modrm_reg & 3] + 1; + return p; +} + +static int read_descriptor(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops, + void *ptr, + u16 *size, unsigned long *address, int op_bytes) +{ + int rc; + + if (op_bytes == 2) + op_bytes = 3; + *address = 0; + rc = ops->read_std((unsigned long)ptr, (unsigned long *)size, 2, + ctxt->vcpu); + if (rc) + return rc; + rc = ops->read_std((unsigned long)ptr + 2, address, op_bytes, + ctxt->vcpu); + 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 decode_register_operand(struct operand *op, + struct decode_cache *c, + int inhibit_bytereg) +{ + unsigned reg = c->modrm_reg; + int highbyte_regs = c->rex_prefix == 0; + + if (!(c->d & ModRM)) + reg = (c->b & 7) | ((c->rex_prefix & 1) << 3); + op->type = OP_REG; + if ((c->d & ByteOp) && !inhibit_bytereg) { + op->ptr = decode_register(reg, c->regs, highbyte_regs); + op->val = *(u8 *)op->ptr; + op->bytes = 1; + } else { + op->ptr = decode_register(reg, c->regs, 0); + op->bytes = c->op_bytes; + switch (op->bytes) { + case 2: + op->val = *(u16 *)op->ptr; + break; + case 4: + op->val = *(u32 *)op->ptr; + break; + case 8: + op->val = *(u64 *) op->ptr; + break; + } + } + op->orig_val = op->val; +} + +static int decode_modrm(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops) +{ + struct decode_cache *c = &ctxt->decode; + u8 sib; + int index_reg = 0, base_reg = 0, scale, rip_relative = 0; + int rc = 0; + + if (c->rex_prefix) { + c->modrm_reg = (c->rex_prefix & 4) << 1; /* REX.R */ + index_reg = (c->rex_prefix & 2) << 2; /* REX.X */ + c->modrm_rm = base_reg = (c->rex_prefix & 1) << 3; /* REG.B */ + } + + c->modrm = insn_fetch(u8, 1, c->eip); + c->modrm_mod |= (c->modrm & 0xc0) >> 6; + c->modrm_reg |= (c->modrm & 0x38) >> 3; + c->modrm_rm |= (c->modrm & 0x07); + c->modrm_ea = 0; + c->use_modrm_ea = 1; + + if (c->modrm_mod == 3) { + c->modrm_val = *(unsigned long *) + decode_register(c->modrm_rm, c->regs, c->d & ByteOp); + return rc; + } + + if (c->ad_bytes == 2) { + unsigned bx = c->regs[VCPU_REGS_RBX]; + unsigned bp = c->regs[VCPU_REGS_RBP]; + unsigned si = c->regs[VCPU_REGS_RSI]; + unsigned di = c->regs[VCPU_REGS_RDI]; + + /* 16-bit ModR/M decode. */ + switch (c->modrm_mod) { + case 0: + if (c->modrm_rm == 6) + c->modrm_ea += insn_fetch(u16, 2, c->eip); + break; + case 1: + c->modrm_ea += insn_fetch(s8, 1, c->eip); + break; + case 2: + c->modrm_ea += insn_fetch(u16, 2, c->eip); + break; + } + switch (c->modrm_rm) { + case 0: + c->modrm_ea += bx + si; + break; + case 1: + c->modrm_ea += bx + di; + break; + case 2: + c->modrm_ea += bp + si; + break; + case 3: + c->modrm_ea += bp + di; + break; + case 4: + c->modrm_ea += si; + break; + case 5: + c->modrm_ea += di; + break; + case 6: + if (c->modrm_mod != 0) + c->modrm_ea += bp; + break; + case 7: + c->modrm_ea += bx; + break; + } + if (c->modrm_rm == 2 || c->modrm_rm == 3 || + (c->modrm_rm == 6 && c->modrm_mod != 0)) + if (!c->override_base) + c->override_base = &ctxt->ss_base; + c->modrm_ea = (u16)c->modrm_ea; + } else { + /* 32/64-bit ModR/M decode. */ + switch (c->modrm_rm) { + case 4: + case 12: + sib = insn_fetch(u8, 1, c->eip); + index_reg |= (sib >> 3) & 7; + base_reg |= sib & 7; + scale = sib >> 6; + + switch (base_reg) { + case 5: + if (c->modrm_mod != 0) + c->modrm_ea += c->regs[base_reg]; + else + c->modrm_ea += + insn_fetch(s32, 4, c->eip); + break; + default: + c->modrm_ea += c->regs[base_reg]; + } + switch (index_reg) { + case 4: + break; + default: + c->modrm_ea += c->regs[index_reg] << scale; + } + break; + case 5: + if (c->modrm_mod != 0) + c->modrm_ea += c->regs[c->modrm_rm]; + else if (ctxt->mode == X86EMUL_MODE_PROT64) + rip_relative = 1; + break; + default: + c->modrm_ea += c->regs[c->modrm_rm]; + break; + } + switch (c->modrm_mod) { + case 0: + if (c->modrm_rm == 5) + c->modrm_ea += insn_fetch(s32, 4, c->eip); + break; + case 1: + c->modrm_ea += insn_fetch(s8, 1, c->eip); + break; + case 2: + c->modrm_ea += insn_fetch(s32, 4, c->eip); + break; + } + } + if (rip_relative) { + c->modrm_ea += c->eip; + switch (c->d & SrcMask) { + case SrcImmByte: + c->modrm_ea += 1; + break; + case SrcImm: + if (c->d & ByteOp) + c->modrm_ea += 1; + else + if (c->op_bytes == 8) + c->modrm_ea += 4; + else + c->modrm_ea += c->op_bytes; + } + } +done: + return rc; +} + +static int decode_abs(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops) +{ + struct decode_cache *c = &ctxt->decode; + int rc = 0; + + switch (c->ad_bytes) { + case 2: + c->modrm_ea = insn_fetch(u16, 2, c->eip); + break; + case 4: + c->modrm_ea = insn_fetch(u32, 4, c->eip); + break; + case 8: + c->modrm_ea = insn_fetch(u64, 8, c->eip); + break; + } +done: + return rc; +} + +int +x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) +{ + struct decode_cache *c = &ctxt->decode; + int rc = 0; + int mode = ctxt->mode; + int def_op_bytes, def_ad_bytes; + + /* Shadow copy of register state. Committed on successful emulation. */ + + memset(c, 0, sizeof(struct decode_cache)); + c->eip = ctxt->vcpu->arch.rip; + memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs); + + switch (mode) { + case X86EMUL_MODE_REAL: + 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 -1; + } + + c->op_bytes = def_op_bytes; + c->ad_bytes = def_ad_bytes; + + /* Legacy prefixes. */ + for (;;) { + switch (c->b = insn_fetch(u8, 1, c->eip)) { + case 0x66: /* operand-size override */ + /* switch between 2/4 bytes */ + c->op_bytes = def_op_bytes ^ 6; + break; + case 0x67: /* address-size override */ + if (mode == X86EMUL_MODE_PROT64) + /* switch between 4/8 bytes */ + c->ad_bytes = def_ad_bytes ^ 12; + else + /* switch between 2/4 bytes */ + c->ad_bytes = def_ad_bytes ^ 6; + break; + case 0x2e: /* CS override */ + c->override_base = &ctxt->cs_base; + break; + case 0x3e: /* DS override */ + c->override_base = &ctxt->ds_base; + break; + case 0x26: /* ES override */ + c->override_base = &ctxt->es_base; + break; + case 0x64: /* FS override */ + c->override_base = &ctxt->fs_base; + break; + case 0x65: /* GS override */ + c->override_base = &ctxt->gs_base; + break; + case 0x36: /* SS override */ + c->override_base = &ctxt->ss_base; + break; + case 0x40 ... 0x4f: /* REX */ + if (mode != X86EMUL_MODE_PROT64) + goto done_prefixes; + c->rex_prefix = c->b; + continue; + case 0xf0: /* LOCK */ + c->lock_prefix = 1; + break; + case 0xf2: /* REPNE/REPNZ */ + c->rep_prefix = REPNE_PREFIX; + break; + case 0xf3: /* REP/REPE/REPZ */ + c->rep_prefix = REPE_PREFIX; + break; + default: + goto done_prefixes; + } + + /* Any legacy prefix after a REX prefix nullifies its effect. */ + + c->rex_prefix = 0; + } + +done_prefixes: + + /* REX prefix. */ + if (c->rex_prefix) + if (c->rex_prefix & 8) + c->op_bytes = 8; /* REX.W */ + + /* Opcode byte(s). */ + c->d = opcode_table[c->b]; + if (c->d == 0) { + /* Two-byte opcode? */ + if (c->b == 0x0f) { + c->twobyte = 1; + c->b = insn_fetch(u8, 1, c->eip); + c->d = twobyte_table[c->b]; + } + + /* Unrecognised? */ + if (c->d == 0) { + DPRINTF("Cannot emulate %02x\n", c->b); + return -1; + } + } + + if (mode == X86EMUL_MODE_PROT64 && (c->d & Stack)) + c->op_bytes = 8; + + /* ModRM and SIB bytes. */ + if (c->d & ModRM) + rc = decode_modrm(ctxt, ops); + else if (c->d & MemAbs) + rc = decode_abs(ctxt, ops); + if (rc) + goto done; + + if (!c->override_base) + c->override_base = &ctxt->ds_base; + if (mode == X86EMUL_MODE_PROT64 && + c->override_base != &ctxt->fs_base && + c->override_base != &ctxt->gs_base) + c->override_base = NULL; + + if (c->override_base) + c->modrm_ea += *c->override_base; + + if (c->ad_bytes != 8) + c->modrm_ea = (u32)c->modrm_ea; + /* + * Decode and fetch the source operand: register, memory + * or immediate. + */ + switch (c->d & SrcMask) { + case SrcNone: + break; + case SrcReg: + decode_register_operand(&c->src, c, 0); + break; + case SrcMem16: + c->src.bytes = 2; + goto srcmem_common; + case SrcMem32: + c->src.bytes = 4; + goto srcmem_common; + case SrcMem: + c->src.bytes = (c->d & ByteOp) ? 1 : + c->op_bytes; + /* Don't fetch the address for invlpg: it could be unmapped. */ + if (c->twobyte && c->b == 0x01 && c->modrm_reg == 7) + break; + srcmem_common: + /* + * For instructions with a ModR/M byte, switch to register + * access if Mod = 3. + */ + if ((c->d & ModRM) && c->modrm_mod == 3) { + c->src.type = OP_REG; + break; + } + c->src.type = OP_MEM; + break; + case SrcImm: + c->src.type = OP_IMM; + c->src.ptr = (unsigned long *)c->eip; + c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + if (c->src.bytes == 8) + c->src.bytes = 4; + /* NB. Immediates are sign-extended as necessary. */ + switch (c->src.bytes) { + case 1: + c->src.val = insn_fetch(s8, 1, c->eip); + break; + case 2: + c->src.val = insn_fetch(s16, 2, c->eip); + break; + case 4: + c->src.val = insn_fetch(s32, 4, c->eip); + break; + } + break; + case SrcImmByte: + c->src.type = OP_IMM; + c->src.ptr = (unsigned long *)c->eip; + c->src.bytes = 1; + c->src.val = insn_fetch(s8, 1, c->eip); + break; + } + + /* Decode and fetch the destination operand: register or memory. */ + switch (c->d & DstMask) { + case ImplicitOps: + /* Special instructions do their own operand decoding. */ + return 0; + case DstReg: + decode_register_operand(&c->dst, c, + c->twobyte && (c->b == 0xb6 || c->b == 0xb7)); + break; + case DstMem: + if ((c->d & ModRM) && c->modrm_mod == 3) { + c->dst.type = OP_REG; + break; + } + c->dst.type = OP_MEM; + break; + } + +done: + return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; +} + +static inline void emulate_push(struct x86_emulate_ctxt *ctxt) +{ + struct decode_cache *c = &ctxt->decode; + + c->dst.type = OP_MEM; + c->dst.bytes = c->op_bytes; + c->dst.val = c->src.val; + register_address_increment(c->regs[VCPU_REGS_RSP], -c->op_bytes); + c->dst.ptr = (void *) register_address(ctxt->ss_base, + c->regs[VCPU_REGS_RSP]); +} + +static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops) +{ + struct decode_cache *c = &ctxt->decode; + int rc; + + rc = ops->read_std(register_address(ctxt->ss_base, + c->regs[VCPU_REGS_RSP]), + &c->dst.val, c->dst.bytes, ctxt->vcpu); + if (rc != 0) + return rc; + + register_address_increment(c->regs[VCPU_REGS_RSP], c->dst.bytes); + + return 0; +} + +static inline void emulate_grp2(struct x86_emulate_ctxt *ctxt) +{ + struct decode_cache *c = &ctxt->decode; + switch (c->modrm_reg) { + case 0: /* rol */ + emulate_2op_SrcB("rol", c->src, c->dst, ctxt->eflags); + break; + case 1: /* ror */ + emulate_2op_SrcB("ror", c->src, c->dst, ctxt->eflags); + break; + case 2: /* rcl */ + emulate_2op_SrcB("rcl", c->src, c->dst, ctxt->eflags); + break; + case 3: /* rcr */ + emulate_2op_SrcB("rcr", c->src, c->dst, ctxt->eflags); + break; + case 4: /* sal/shl */ + case 6: /* sal/shl */ + emulate_2op_SrcB("sal", c->src, c->dst, ctxt->eflags); + break; + case 5: /* shr */ + emulate_2op_SrcB("shr", c->src, c->dst, ctxt->eflags); + break; + case 7: /* sar */ + emulate_2op_SrcB("sar", c->src, c->dst, ctxt->eflags); + break; + } +} + +static inline int emulate_grp3(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops) +{ + struct decode_cache *c = &ctxt->decode; + int rc = 0; + + switch (c->modrm_reg) { + case 0 ... 1: /* test */ + /* + * Special case in Grp3: test has an immediate + * source operand. + */ + c->src.type = OP_IMM; + c->src.ptr = (unsigned long *)c->eip; + c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + if (c->src.bytes == 8) + c->src.bytes = 4; + switch (c->src.bytes) { + case 1: + c->src.val = insn_fetch(s8, 1, c->eip); + break; + case 2: + c->src.val = insn_fetch(s16, 2, c->eip); + break; + case 4: + c->src.val = insn_fetch(s32, 4, c->eip); + break; + } + emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags); + break; + case 2: /* not */ + c->dst.val = ~c->dst.val; + break; + case 3: /* neg */ + emulate_1op("neg", c->dst, ctxt->eflags); + break; + default: + DPRINTF("Cannot emulate %02x\n", c->b); + rc = X86EMUL_UNHANDLEABLE; + break; + } +done: + return rc; +} + +static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops) +{ + struct decode_cache *c = &ctxt->decode; + int rc; + + switch (c->modrm_reg) { + case 0: /* inc */ + emulate_1op("inc", c->dst, ctxt->eflags); + break; + case 1: /* dec */ + emulate_1op("dec", c->dst, ctxt->eflags); + break; + case 4: /* jmp abs */ + if (c->b == 0xff) + c->eip = c->dst.val; + else { + DPRINTF("Cannot emulate %02x\n", c->b); + return X86EMUL_UNHANDLEABLE; + } + break; + case 6: /* push */ + + /* 64-bit mode: PUSH always pushes a 64-bit operand. */ + + if (ctxt->mode == X86EMUL_MODE_PROT64) { + c->dst.bytes = 8; + rc = ops->read_std((unsigned long)c->dst.ptr, + &c->dst.val, 8, ctxt->vcpu); + if (rc != 0) + return rc; + } + register_address_increment(c->regs[VCPU_REGS_RSP], + -c->dst.bytes); + rc = ops->write_emulated(register_address(ctxt->ss_base, + c->regs[VCPU_REGS_RSP]), &c->dst.val, + c->dst.bytes, ctxt->vcpu); + if (rc != 0) + return rc; + c->dst.type = OP_NONE; + break; + default: + DPRINTF("Cannot emulate %02x\n", c->b); + return X86EMUL_UNHANDLEABLE; + } + return 0; +} + +static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops, + unsigned long memop) +{ + struct decode_cache *c = &ctxt->decode; + u64 old, new; + int rc; + + rc = ops->read_emulated(memop, &old, 8, ctxt->vcpu); + if (rc != 0) + return rc; + + if (((u32) (old >> 0) != (u32) c->regs[VCPU_REGS_RAX]) || + ((u32) (old >> 32) != (u32) c->regs[VCPU_REGS_RDX])) { + + c->regs[VCPU_REGS_RAX] = (u32) (old >> 0); + c->regs[VCPU_REGS_RDX] = (u32) (old >> 32); + ctxt->eflags &= ~EFLG_ZF; + + } else { + new = ((u64)c->regs[VCPU_REGS_RCX] << 32) | + (u32) c->regs[VCPU_REGS_RBX]; + + rc = ops->cmpxchg_emulated(memop, &old, &new, 8, ctxt->vcpu); + if (rc != 0) + return rc; + ctxt->eflags |= EFLG_ZF; + } + return 0; +} + +static inline int writeback(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops) +{ + int rc; + struct decode_cache *c = &ctxt->decode; + + switch (c->dst.type) { + case OP_REG: + /* The 4-byte case *is* correct: + * in 64-bit mode we zero-extend. + */ + switch (c->dst.bytes) { + case 1: + *(u8 *)c->dst.ptr = (u8)c->dst.val; + break; + case 2: + *(u16 *)c->dst.ptr = (u16)c->dst.val; + break; + case 4: + *c->dst.ptr = (u32)c->dst.val; + break; /* 64b: zero-ext */ + case 8: + *c->dst.ptr = c->dst.val; + break; + } + break; + case OP_MEM: + if (c->lock_prefix) + rc = ops->cmpxchg_emulated( + (unsigned long)c->dst.ptr, + &c->dst.orig_val, + &c->dst.val, + c->dst.bytes, + ctxt->vcpu); + else + rc = ops->write_emulated( + (unsigned long)c->dst.ptr, + &c->dst.val, + c->dst.bytes, + ctxt->vcpu); + if (rc != 0) + return rc; + break; + case OP_NONE: + /* no writeback */ + break; + default: + break; + } + return 0; +} + +int +x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) +{ + unsigned long memop = 0; + u64 msr_data; + unsigned long saved_eip = 0; + struct decode_cache *c = &ctxt->decode; + int rc = 0; + + /* Shadow copy of register state. Committed on successful emulation. + * NOTE: we can copy them from vcpu as x86_decode_insn() doesn't + * modify them. + */ + + memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs); + saved_eip = c->eip; + + if (((c->d & ModRM) && (c->modrm_mod != 3)) || (c->d & MemAbs)) + memop = c->modrm_ea; + + if (c->rep_prefix && (c->d & String)) { + /* All REP prefixes have the same first termination condition */ + if (c->regs[VCPU_REGS_RCX] == 0) { + ctxt->vcpu->arch.rip = c->eip; + goto done; + } + /* 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 ((c->b == 0xa6) || (c->b == 0xa7) || + (c->b == 0xae) || (c->b == 0xaf)) { + if ((c->rep_prefix == REPE_PREFIX) && + ((ctxt->eflags & EFLG_ZF) == 0)) { + ctxt->vcpu->arch.rip = c->eip; + goto done; + } + if ((c->rep_prefix == REPNE_PREFIX) && + ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)) { + ctxt->vcpu->arch.rip = c->eip; + goto done; + } + } + c->regs[VCPU_REGS_RCX]--; + c->eip = ctxt->vcpu->arch.rip; + } + + if (c->src.type == OP_MEM) { + c->src.ptr = (unsigned long *)memop; + c->src.val = 0; + rc = ops->read_emulated((unsigned long)c->src.ptr, + &c->src.val, + c->src.bytes, + ctxt->vcpu); + if (rc != 0) + goto done; + c->src.orig_val = c->src.val; + } + + if ((c->d & DstMask) == ImplicitOps) + goto special_insn; + + + if (c->dst.type == OP_MEM) { + c->dst.ptr = (unsigned long *)memop; + c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + c->dst.val = 0; + if (c->d & BitOp) { + unsigned long mask = ~(c->dst.bytes * 8 - 1); + + c->dst.ptr = (void *)c->dst.ptr + + (c->src.val & mask) / 8; + } + if (!(c->d & Mov) && + /* optimisation - avoid slow emulated read */ + ((rc = ops->read_emulated((unsigned long)c->dst.ptr, + &c->dst.val, + c->dst.bytes, ctxt->vcpu)) != 0)) + goto done; + } + c->dst.orig_val = c->dst.val; + +special_insn: + + if (c->twobyte) + goto twobyte_insn; + + switch (c->b) { + case 0x00 ... 0x05: + add: /* add */ + emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags); + break; + case 0x08 ... 0x0d: + or: /* or */ + emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags); + break; + case 0x10 ... 0x15: + adc: /* adc */ + emulate_2op_SrcV("adc", c->src, c->dst, ctxt->eflags); + break; + case 0x18 ... 0x1d: + sbb: /* sbb */ + emulate_2op_SrcV("sbb", c->src, c->dst, ctxt->eflags); + break; + case 0x20 ... 0x23: + and: /* and */ + emulate_2op_SrcV("and", c->src, c->dst, ctxt->eflags); + break; + case 0x24: /* and al imm8 */ + c->dst.type = OP_REG; + c->dst.ptr = &c->regs[VCPU_REGS_RAX]; + c->dst.val = *(u8 *)c->dst.ptr; + c->dst.bytes = 1; + c->dst.orig_val = c->dst.val; + goto and; + case 0x25: /* and ax imm16, or eax imm32 */ + c->dst.type = OP_REG; + c->dst.bytes = c->op_bytes; + c->dst.ptr = &c->regs[VCPU_REGS_RAX]; + if (c->op_bytes == 2) + c->dst.val = *(u16 *)c->dst.ptr; + else + c->dst.val = *(u32 *)c->dst.ptr; + c->dst.orig_val = c->dst.val; + goto and; + case 0x28 ... 0x2d: + sub: /* sub */ + emulate_2op_SrcV("sub", c->src, c->dst, ctxt->eflags); + break; + case 0x30 ... 0x35: + xor: /* xor */ + emulate_2op_SrcV("xor", c->src, c->dst, ctxt->eflags); + break; + case 0x38 ... 0x3d: + cmp: /* cmp */ + emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); + break; + case 0x40 ... 0x47: /* inc r16/r32 */ + emulate_1op("inc", c->dst, ctxt->eflags); + break; + case 0x48 ... 0x4f: /* dec r16/r32 */ + emulate_1op("dec", c->dst, ctxt->eflags); + break; + case 0x50 ... 0x57: /* push reg */ + c->dst.type = OP_MEM; + c->dst.bytes = c->op_bytes; + c->dst.val = c->src.val; + register_address_increment(c->regs[VCPU_REGS_RSP], + -c->op_bytes); + c->dst.ptr = (void *) register_address( + ctxt->ss_base, c->regs[VCPU_REGS_RSP]); + break; + case 0x58 ... 0x5f: /* pop reg */ + pop_instruction: + if ((rc = ops->read_std(register_address(ctxt->ss_base, + c->regs[VCPU_REGS_RSP]), c->dst.ptr, + c->op_bytes, ctxt->vcpu)) != 0) + goto done; + + register_address_increment(c->regs[VCPU_REGS_RSP], + c->op_bytes); + c->dst.type = OP_NONE; /* Disable writeback. */ + break; + case 0x63: /* movsxd */ + if (ctxt->mode != X86EMUL_MODE_PROT64) + goto cannot_emulate; + c->dst.val = (s32) c->src.val; + break; + case 0x6a: /* push imm8 */ + c->src.val = 0L; + c->src.val = insn_fetch(s8, 1, c->eip); + emulate_push(ctxt); + break; + case 0x6c: /* insb */ + case 0x6d: /* insw/insd */ + if (kvm_emulate_pio_string(ctxt->vcpu, NULL, + 1, + (c->d & ByteOp) ? 1 : c->op_bytes, + c->rep_prefix ? + address_mask(c->regs[VCPU_REGS_RCX]) : 1, + (ctxt->eflags & EFLG_DF), + register_address(ctxt->es_base, + c->regs[VCPU_REGS_RDI]), + c->rep_prefix, + c->regs[VCPU_REGS_RDX]) == 0) { + c->eip = saved_eip; + return -1; + } + return 0; + case 0x6e: /* outsb */ + case 0x6f: /* outsw/outsd */ + if (kvm_emulate_pio_string(ctxt->vcpu, NULL, + 0, + (c->d & ByteOp) ? 1 : c->op_bytes, + c->rep_prefix ? + address_mask(c->regs[VCPU_REGS_RCX]) : 1, + (ctxt->eflags & EFLG_DF), + register_address(c->override_base ? + *c->override_base : + ctxt->ds_base, + c->regs[VCPU_REGS_RSI]), + c->rep_prefix, + c->regs[VCPU_REGS_RDX]) == 0) { + c->eip = saved_eip; + return -1; + } + return 0; + case 0x70 ... 0x7f: /* jcc (short) */ { + int rel = insn_fetch(s8, 1, c->eip); + + if (test_cc(c->b, ctxt->eflags)) + JMP_REL(rel); + break; + } + case 0x80 ... 0x83: /* Grp1 */ + switch (c->modrm_reg) { + case 0: + goto add; + case 1: + goto or; + case 2: + goto adc; + case 3: + goto sbb; + case 4: + goto and; + case 5: + goto sub; + case 6: + goto xor; + case 7: + goto cmp; + } + break; + case 0x84 ... 0x85: + emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags); + break; + case 0x86 ... 0x87: /* xchg */ + /* Write back the register source. */ + switch (c->dst.bytes) { + case 1: + *(u8 *) c->src.ptr = (u8) c->dst.val; + break; + case 2: + *(u16 *) c->src.ptr = (u16) c->dst.val; + break; + case 4: + *c->src.ptr = (u32) c->dst.val; + break; /* 64b reg: zero-extend */ + case 8: + *c->src.ptr = c->dst.val; + break; + } + /* + * Write back the memory destination with implicit LOCK + * prefix. + */ + c->dst.val = c->src.val; + c->lock_prefix = 1; + break; + case 0x88 ... 0x8b: /* mov */ + goto mov; + case 0x8d: /* lea r16/r32, m */ + c->dst.val = c->modrm_val; + break; + case 0x8f: /* pop (sole member of Grp1a) */ + rc = emulate_grp1a(ctxt, ops); + if (rc != 0) + goto done; + break; + case 0x9c: /* pushf */ + c->src.val = (unsigned long) ctxt->eflags; + emulate_push(ctxt); + break; + case 0x9d: /* popf */ + c->dst.ptr = (unsigned long *) &ctxt->eflags; + goto pop_instruction; + case 0xa0 ... 0xa1: /* mov */ + c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX]; + c->dst.val = c->src.val; + break; + case 0xa2 ... 0xa3: /* mov */ + c->dst.val = (unsigned long)c->regs[VCPU_REGS_RAX]; + break; + case 0xa4 ... 0xa5: /* movs */ + c->dst.type = OP_MEM; + c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + c->dst.ptr = (unsigned long *)register_address( + ctxt->es_base, + c->regs[VCPU_REGS_RDI]); + if ((rc = ops->read_emulated(register_address( + c->override_base ? *c->override_base : + ctxt->ds_base, + c->regs[VCPU_REGS_RSI]), + &c->dst.val, + c->dst.bytes, ctxt->vcpu)) != 0) + goto done; + register_address_increment(c->regs[VCPU_REGS_RSI], + (ctxt->eflags & EFLG_DF) ? -c->dst.bytes + : c->dst.bytes); + register_address_increment(c->regs[VCPU_REGS_RDI], + (ctxt->eflags & EFLG_DF) ? -c->dst.bytes + : c->dst.bytes); + break; + case 0xa6 ... 0xa7: /* cmps */ + c->src.type = OP_NONE; /* Disable writeback. */ + c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + c->src.ptr = (unsigned long *)register_address( + c->override_base ? *c->override_base : + ctxt->ds_base, + c->regs[VCPU_REGS_RSI]); + if ((rc = ops->read_emulated((unsigned long)c->src.ptr, + &c->src.val, + c->src.bytes, + ctxt->vcpu)) != 0) + goto done; + + c->dst.type = OP_NONE; /* Disable writeback. */ + c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + c->dst.ptr = (unsigned long *)register_address( + ctxt->es_base, + c->regs[VCPU_REGS_RDI]); + if ((rc = ops->read_emulated((unsigned long)c->dst.ptr, + &c->dst.val, + c->dst.bytes, + ctxt->vcpu)) != 0) + goto done; + + DPRINTF("cmps: mem1=0x%p mem2=0x%p\n", c->src.ptr, c->dst.ptr); + + emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); + + register_address_increment(c->regs[VCPU_REGS_RSI], + (ctxt->eflags & EFLG_DF) ? -c->src.bytes + : c->src.bytes); + register_address_increment(c->regs[VCPU_REGS_RDI], + (ctxt->eflags & EFLG_DF) ? -c->dst.bytes + : c->dst.bytes); + + break; + case 0xaa ... 0xab: /* stos */ + c->dst.type = OP_MEM; + c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + c->dst.ptr = (unsigned long *)register_address( + ctxt->es_base, + c->regs[VCPU_REGS_RDI]); + c->dst.val = c->regs[VCPU_REGS_RAX]; + register_address_increment(c->regs[VCPU_REGS_RDI], + (ctxt->eflags & EFLG_DF) ? -c->dst.bytes + : c->dst.bytes); + break; + case 0xac ... 0xad: /* lods */ + c->dst.type = OP_REG; + c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX]; + if ((rc = ops->read_emulated(register_address( + c->override_base ? *c->override_base : + ctxt->ds_base, + c->regs[VCPU_REGS_RSI]), + &c->dst.val, + c->dst.bytes, + ctxt->vcpu)) != 0) + goto done; + register_address_increment(c->regs[VCPU_REGS_RSI], + (ctxt->eflags & EFLG_DF) ? -c->dst.bytes + : c->dst.bytes); + break; + case 0xae ... 0xaf: /* scas */ + DPRINTF("Urk! I don't handle SCAS.\n"); + goto cannot_emulate; + case 0xc0 ... 0xc1: + emulate_grp2(ctxt); + break; + case 0xc3: /* ret */ + c->dst.ptr = &c->eip; + goto pop_instruction; + case 0xc6 ... 0xc7: /* mov (sole member of Grp11) */ + mov: + c->dst.val = c->src.val; + break; + case 0xd0 ... 0xd1: /* Grp2 */ + c->src.val = 1; + emulate_grp2(ctxt); + break; + case 0xd2 ... 0xd3: /* Grp2 */ + c->src.val = c->regs[VCPU_REGS_RCX]; + emulate_grp2(ctxt); + break; + case 0xe8: /* call (near) */ { + long int rel; + switch (c->op_bytes) { + case 2: + rel = insn_fetch(s16, 2, c->eip); + break; + case 4: + rel = insn_fetch(s32, 4, c->eip); + break; + default: + DPRINTF("Call: Invalid op_bytes\n"); + goto cannot_emulate; + } + c->src.val = (unsigned long) c->eip; + JMP_REL(rel); + c->op_bytes = c->ad_bytes; + emulate_push(ctxt); + break; + } + case 0xe9: /* jmp rel */ + case 0xeb: /* jmp rel short */ + JMP_REL(c->src.val); + c->dst.type = OP_NONE; /* Disable writeback. */ + break; + case 0xf4: /* hlt */ + ctxt->vcpu->arch.halt_request = 1; + goto done; + case 0xf5: /* cmc */ + /* complement carry flag from eflags reg */ + ctxt->eflags ^= EFLG_CF; + c->dst.type = OP_NONE; /* Disable writeback. */ + break; + case 0xf6 ... 0xf7: /* Grp3 */ + rc = emulate_grp3(ctxt, ops); + if (rc != 0) + goto done; + break; + case 0xf8: /* clc */ + ctxt->eflags &= ~EFLG_CF; + c->dst.type = OP_NONE; /* Disable writeback. */ + break; + case 0xfa: /* cli */ + ctxt->eflags &= ~X86_EFLAGS_IF; + c->dst.type = OP_NONE; /* Disable writeback. */ + break; + case 0xfb: /* sti */ + ctxt->eflags |= X86_EFLAGS_IF; + c->dst.type = OP_NONE; /* Disable writeback. */ + break; + case 0xfe ... 0xff: /* Grp4/Grp5 */ + rc = emulate_grp45(ctxt, ops); + if (rc != 0) + goto done; + break; + } + +writeback: + rc = writeback(ctxt, ops); + if (rc != 0) + goto done; + + /* Commit shadow register state. */ + memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs); + ctxt->vcpu->arch.rip = c->eip; + +done: + if (rc == X86EMUL_UNHANDLEABLE) { + c->eip = saved_eip; + return -1; + } + return 0; + +twobyte_insn: + switch (c->b) { + case 0x01: /* lgdt, lidt, lmsw */ + switch (c->modrm_reg) { + u16 size; + unsigned long address; + + case 0: /* vmcall */ + if (c->modrm_mod != 3 || c->modrm_rm != 1) + goto cannot_emulate; + + rc = kvm_fix_hypercall(ctxt->vcpu); + if (rc) + goto done; + + kvm_emulate_hypercall(ctxt->vcpu); + break; + case 2: /* lgdt */ + rc = read_descriptor(ctxt, ops, c->src.ptr, + &size, &address, c->op_bytes); + if (rc) + goto done; + realmode_lgdt(ctxt->vcpu, size, address); + break; + case 3: /* lidt/vmmcall */ + if (c->modrm_mod == 3 && c->modrm_rm == 1) { + rc = kvm_fix_hypercall(ctxt->vcpu); + if (rc) + goto done; + kvm_emulate_hypercall(ctxt->vcpu); + } else { + rc = read_descriptor(ctxt, ops, c->src.ptr, + &size, &address, + c->op_bytes); + if (rc) + goto done; + realmode_lidt(ctxt->vcpu, size, address); + } + break; + case 4: /* smsw */ + if (c->modrm_mod != 3) + goto cannot_emulate; + *(u16 *)&c->regs[c->modrm_rm] + = realmode_get_cr(ctxt->vcpu, 0); + break; + case 6: /* lmsw */ + if (c->modrm_mod != 3) + goto cannot_emulate; + realmode_lmsw(ctxt->vcpu, (u16)c->modrm_val, + &ctxt->eflags); + break; + case 7: /* invlpg*/ + emulate_invlpg(ctxt->vcpu, memop); + break; + default: + goto cannot_emulate; + } + /* Disable writeback. */ + c->dst.type = OP_NONE; + break; + case 0x06: + emulate_clts(ctxt->vcpu); + c->dst.type = OP_NONE; + break; + case 0x08: /* invd */ + case 0x09: /* wbinvd */ + case 0x0d: /* GrpP (prefetch) */ + case 0x18: /* Grp16 (prefetch/nop) */ + c->dst.type = OP_NONE; + break; + case 0x20: /* mov cr, reg */ + if (c->modrm_mod != 3) + goto cannot_emulate; + c->regs[c->modrm_rm] = + realmode_get_cr(ctxt->vcpu, c->modrm_reg); + c->dst.type = OP_NONE; /* no writeback */ + break; + case 0x21: /* mov from dr to reg */ + if (c->modrm_mod != 3) + goto cannot_emulate; + rc = emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm]); + if (rc) + goto cannot_emulate; + c->dst.type = OP_NONE; /* no writeback */ + break; + case 0x22: /* mov reg, cr */ + if (c->modrm_mod != 3) + goto cannot_emulate; + realmode_set_cr(ctxt->vcpu, + c->modrm_reg, c->modrm_val, &ctxt->eflags); + c->dst.type = OP_NONE; + break; + case 0x23: /* mov from reg to dr */ + if (c->modrm_mod != 3) + goto cannot_emulate; + rc = emulator_set_dr(ctxt, c->modrm_reg, + c->regs[c->modrm_rm]); + if (rc) + goto cannot_emulate; + c->dst.type = OP_NONE; /* no writeback */ + break; + case 0x30: + /* wrmsr */ + msr_data = (u32)c->regs[VCPU_REGS_RAX] + | ((u64)c->regs[VCPU_REGS_RDX] << 32); + rc = kvm_set_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], msr_data); + if (rc) { + kvm_inject_gp(ctxt->vcpu, 0); + c->eip = ctxt->vcpu->arch.rip; + } + rc = X86EMUL_CONTINUE; + c->dst.type = OP_NONE; + break; + case 0x32: + /* rdmsr */ + rc = kvm_get_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], &msr_data); + if (rc) { + kvm_inject_gp(ctxt->vcpu, 0); + c->eip = ctxt->vcpu->arch.rip; + } else { + c->regs[VCPU_REGS_RAX] = (u32)msr_data; + c->regs[VCPU_REGS_RDX] = msr_data >> 32; + } + rc = X86EMUL_CONTINUE; + c->dst.type = OP_NONE; + break; + case 0x40 ... 0x4f: /* cmov */ + c->dst.val = c->dst.orig_val = c->src.val; + if (!test_cc(c->b, ctxt->eflags)) + c->dst.type = OP_NONE; /* no writeback */ + break; + case 0x80 ... 0x8f: /* jnz rel, etc*/ { + long int rel; + + switch (c->op_bytes) { + case 2: + rel = insn_fetch(s16, 2, c->eip); + break; + case 4: + rel = insn_fetch(s32, 4, c->eip); + break; + case 8: + rel = insn_fetch(s64, 8, c->eip); + break; + default: + DPRINTF("jnz: Invalid op_bytes\n"); + goto cannot_emulate; + } + if (test_cc(c->b, ctxt->eflags)) + JMP_REL(rel); + c->dst.type = OP_NONE; + break; + } + case 0xa3: + bt: /* bt */ + c->dst.type = OP_NONE; + /* only subword offset */ + c->src.val &= (c->dst.bytes << 3) - 1; + emulate_2op_SrcV_nobyte("bt", c->src, c->dst, ctxt->eflags); + break; + case 0xab: + bts: /* bts */ + /* only subword offset */ + c->src.val &= (c->dst.bytes << 3) - 1; + emulate_2op_SrcV_nobyte("bts", c->src, c->dst, ctxt->eflags); + break; + case 0xb0 ... 0xb1: /* cmpxchg */ + /* + * Save real source value, then compare EAX against + * destination. + */ + c->src.orig_val = c->src.val; + c->src.val = c->regs[VCPU_REGS_RAX]; + emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); + if (ctxt->eflags & EFLG_ZF) { + /* Success: write back to memory. */ + c->dst.val = c->src.orig_val; + } else { + /* Failure: write the value we saw to EAX. */ + c->dst.type = OP_REG; + c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX]; + } + break; + case 0xb3: + btr: /* btr */ + /* only subword offset */ + c->src.val &= (c->dst.bytes << 3) - 1; + emulate_2op_SrcV_nobyte("btr", c->src, c->dst, ctxt->eflags); + break; + case 0xb6 ... 0xb7: /* movzx */ + c->dst.bytes = c->op_bytes; + c->dst.val = (c->d & ByteOp) ? (u8) c->src.val + : (u16) c->src.val; + break; + case 0xba: /* Grp8 */ + switch (c->modrm_reg & 3) { + case 0: + goto bt; + case 1: + goto bts; + case 2: + goto btr; + case 3: + goto btc; + } + break; + case 0xbb: + btc: /* btc */ + /* only subword offset */ + c->src.val &= (c->dst.bytes << 3) - 1; + emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags); + break; + case 0xbe ... 0xbf: /* movsx */ + c->dst.bytes = c->op_bytes; + c->dst.val = (c->d & ByteOp) ? (s8) c->src.val : + (s16) c->src.val; + break; + case 0xc3: /* movnti */ + c->dst.bytes = c->op_bytes; + c->dst.val = (c->op_bytes == 4) ? (u32) c->src.val : + (u64) c->src.val; + break; + case 0xc7: /* Grp9 (cmpxchg8b) */ + rc = emulate_grp9(ctxt, ops, memop); + if (rc != 0) + goto done; + c->dst.type = OP_NONE; + break; + } + goto writeback; + +cannot_emulate: + DPRINTF("Cannot emulate %02x\n", c->b); + c->eip = saved_eip; + return -1; +} |