diff options
Diffstat (limited to 'drivers/kvm/x86_emulate.c')
| -rw-r--r-- | drivers/kvm/x86_emulate.c | 1409 |
1 files changed, 1409 insertions, 0 deletions
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c new file mode 100644 index 0000000000000..7e838bf0592df --- /dev/null +++ b/drivers/kvm/x86_emulate.c @@ -0,0 +1,1409 @@ +/****************************************************************************** + * 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 + * privieged 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 "kvm.h" +#define DPRINTF(x...) do {} while (0) +#endif +#include "x86_emulate.h" +#include <linux/module.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) + +static u8 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, + 0, 0, 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 - 0x4F */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0x50 - 0x5F */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0x60 - 0x6F */ + 0, 0, 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ , + 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 - 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, 0, 0, DstMem | SrcNone | ModRM | Mov, + /* 0x90 - 0x9F */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0xA0 - 0xA7 */ + ByteOp | DstReg | SrcMem | Mov, DstReg | SrcMem | Mov, + ByteOp | DstMem | SrcReg | Mov, DstMem | SrcReg | Mov, + ByteOp | ImplicitOps | Mov, ImplicitOps | Mov, + ByteOp | ImplicitOps, ImplicitOps, + /* 0xA8 - 0xAF */ + 0, 0, ByteOp | ImplicitOps | Mov, ImplicitOps | Mov, + ByteOp | ImplicitOps | Mov, ImplicitOps | Mov, + ByteOp | ImplicitOps, ImplicitOps, + /* 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, 0, + 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 - 0xEF */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0xF0 - 0xF7 */ + 0, 0, 0, 0, + 0, 0, ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM, + /* 0xF8 - 0xFF */ + 0, 0, 0, 0, + 0, 0, ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM +}; + +static u8 twobyte_table[256] = { + /* 0x00 - 0x0F */ + 0, SrcMem | ModRM | DstReg, 0, 0, 0, 0, ImplicitOps, 0, + 0, 0, 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 */ + 0, 0, 0, 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 */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 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, 0, 0, 0, 0, + /* 0xA8 - 0xAF */ + 0, 0, 0, DstMem | SrcReg | ModRM, 0, 0, 0, 0, + /* 0xB0 - 0xB7 */ + ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, 0, + DstMem | SrcReg | ModRM, + 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov, + DstReg | SrcMem16 | ModRM | Mov, + /* 0xB8 - 0xBF */ + 0, 0, DstMem | SrcImmByte | ModRM, DstMem | SrcReg | ModRM, + 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov, + DstReg | SrcMem16 | ModRM | Mov, + /* 0xC0 - 0xCF */ + 0, 0, 0, 0, 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 +}; + +/* + * Tell the emulator that of the Group 7 instructions (sgdt, lidt, etc.) we + * are interested only in invlpg and not in any of the rest. + * + * invlpg is a special instruction in that the data it references may not + * be mapped. + */ +void kvm_emulator_want_group7_invlpg(void) +{ + twobyte_table[1] &= ~SrcMem; +} +EXPORT_SYMBOL_GPL(kvm_emulator_want_group7_invlpg); + +/* Type, address-of, and value of an instruction's operand. */ +struct operand { + enum { OP_REG, OP_MEM, OP_IMM } type; + unsigned int bytes; + unsigned long val, orig_val, *ptr; +}; + +/* 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(__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); */ \ + "push %"_sav"; " \ + "movl %"_msk",%"_LO32 _tmp"; " \ + "andl %"_LO32 _tmp",("_STK"); " \ + "pushf; " \ + "notl %"_LO32 _tmp"; " \ + "andl %"_LO32 _tmp",("_STK"); " \ + "pop %"_tmp"; " \ + "orl %"_LO32 _tmp",("_STK"); " \ + "popf; " \ + /* _sav &= ~msk; */ \ + "movl %"_msk",%"_LO32 _tmp"; " \ + "notl %"_LO32 _tmp"; " \ + "andl %"_LO32 _tmp",%"_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(__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 = ops->read_std((unsigned long)(_eip) + ctxt->cs_base, &_x, \ + (_size), ctxt); \ + if ( rc != 0 ) \ + goto done; \ + (_eip) += (_size); \ + (_type)_x; \ +}) + +/* Access/update address held in a register, based on addressing mode. */ +#define register_address(base, reg) \ + ((base) + ((ad_bytes == sizeof(unsigned long)) ? (reg) : \ + ((reg) & ((1UL << (ad_bytes << 3)) - 1)))) + +#define register_address_increment(reg, inc) \ + do { \ + /* signed type ensures sign extension to long */ \ + int _inc = (inc); \ + if ( ad_bytes == sizeof(unsigned long) ) \ + (reg) += _inc; \ + else \ + (reg) = ((reg) & ~((1UL << (ad_bytes << 3)) - 1)) | \ + (((reg) + _inc) & ((1UL << (ad_bytes << 3)) - 1)); \ + } while (0) + +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); + if (rc) + return rc; + rc = ops->read_std((unsigned long)ptr + 2, address, op_bytes, ctxt); + return rc; +} + +int +x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) +{ + u8 b, d, sib, twobyte = 0, rex_prefix = 0; + u8 modrm, modrm_mod = 0, modrm_reg = 0, modrm_rm = 0; + unsigned long *override_base = NULL; + unsigned int op_bytes, ad_bytes, lock_prefix = 0, rep_prefix = 0, i; + int rc = 0; + struct operand src, dst; + unsigned long cr2 = ctxt->cr2; + int mode = ctxt->mode; + unsigned long modrm_ea; + int use_modrm_ea, index_reg = 0, base_reg = 0, scale, rip_relative = 0; + + /* Shadow copy of register state. Committed on successful emulation. */ + unsigned long _regs[NR_VCPU_REGS]; + unsigned long _eip = ctxt->vcpu->rip, _eflags = ctxt->eflags; + unsigned long modrm_val = 0; + + memcpy(_regs, ctxt->vcpu->regs, sizeof _regs); + + switch (mode) { + case X86EMUL_MODE_REAL: + case X86EMUL_MODE_PROT16: + op_bytes = ad_bytes = 2; + break; + case X86EMUL_MODE_PROT32: + op_bytes = ad_bytes = 4; + break; +#ifdef __x86_64__ + case X86EMUL_MODE_PROT64: + op_bytes = 4; + ad_bytes = 8; + break; +#endif + default: + return -1; + } + + /* Legacy prefixes. */ + for (i = 0; i < 8; i++) { + switch (b = insn_fetch(u8, 1, _eip)) { + case 0x66: /* operand-size override */ + op_bytes ^= 6; /* switch between 2/4 bytes */ + break; + case 0x67: /* address-size override */ + if (mode == X86EMUL_MODE_PROT64) + ad_bytes ^= 12; /* switch between 4/8 bytes */ + else + ad_bytes ^= 6; /* switch between 2/4 bytes */ + break; + case 0x2e: /* CS override */ + override_base = &ctxt->cs_base; + break; + case 0x3e: /* DS override */ + override_base = &ctxt->ds_base; + break; + case 0x26: /* ES override */ + override_base = &ctxt->es_base; + break; + case 0x64: /* FS override */ + override_base = &ctxt->fs_base; + break; + case 0x65: /* GS override */ + override_base = &ctxt->gs_base; + break; + case 0x36: /* SS override */ + override_base = &ctxt->ss_base; + break; + case 0xf0: /* LOCK */ + lock_prefix = 1; + break; + case 0xf3: /* REP/REPE/REPZ */ + rep_prefix = 1; + break; + case 0xf2: /* REPNE/REPNZ */ + break; + default: + goto done_prefixes; + } + } + +done_prefixes: + + /* REX prefix. */ + if ((mode == X86EMUL_MODE_PROT64) && ((b & 0xf0) == 0x40)) { + rex_prefix = b; + if (b & 8) + op_bytes = 8; /* REX.W */ + modrm_reg = (b & 4) << 1; /* REX.R */ + index_reg = (b & 2) << 2; /* REX.X */ + modrm_rm = base_reg = (b & 1) << 3; /* REG.B */ + b = insn_fetch(u8, 1, _eip); + } + + /* Opcode byte(s). */ + d = opcode_table[b]; + if (d == 0) { + /* Two-byte opcode? */ + if (b == 0x0f) { + twobyte = 1; + b = insn_fetch(u8, 1, _eip); + d = twobyte_table[b]; + } + + /* Unrecognised? */ + if (d == 0) + goto cannot_emulate; + } + + /* ModRM and SIB bytes. */ + if (d & ModRM) { + modrm = insn_fetch(u8, 1, _eip); + modrm_mod |= (modrm & 0xc0) >> 6; + modrm_reg |= (modrm & 0x38) >> 3; + modrm_rm |= (modrm & 0x07); + modrm_ea = 0; + use_modrm_ea = 1; + + if (modrm_mod == 3) { + modrm_val = *(unsigned long *) + decode_register(modrm_rm, _regs, d & ByteOp); + goto modrm_done; + } + + if (ad_bytes == 2) { + unsigned bx = _regs[VCPU_REGS_RBX]; + unsigned bp = _regs[VCPU_REGS_RBP]; + unsigned si = _regs[VCPU_REGS_RSI]; + unsigned di = _regs[VCPU_REGS_RDI]; + + /* 16-bit ModR/M decode. */ + switch (modrm_mod) { + case 0: + if (modrm_rm == 6) + modrm_ea += insn_fetch(u16, 2, _eip); + break; + case 1: + modrm_ea += insn_fetch(s8, 1, _eip); + break; + case 2: + modrm_ea += insn_fetch(u16, 2, _eip); + break; + } + switch (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 (modrm_mod != 0) + modrm_ea += bp; + break; + case 7: + modrm_ea += bx; + break; + } + if (modrm_rm == 2 || modrm_rm == 3 || + (modrm_rm == 6 && modrm_mod != 0)) + if (!override_base) + override_base = &ctxt->ss_base; + modrm_ea = (u16)modrm_ea; + } else { + /* 32/64-bit ModR/M decode. */ + switch (modrm_rm) { + case 4: + case 12: + sib = insn_fetch(u8, 1, _eip); + index_reg |= (sib >> 3) & 7; + base_reg |= sib & 7; + scale = sib >> 6; + + switch (base_reg) { + case 5: + if (modrm_mod != 0) + modrm_ea += _regs[base_reg]; + else + modrm_ea += insn_fetch(s32, 4, _eip); + break; + default: + modrm_ea += _regs[base_reg]; + } + switch (index_reg) { + case 4: + break; + default: + modrm_ea += _regs[index_reg] << scale; + + } + break; + case 5: + if (modrm_mod != 0) + modrm_ea += _regs[modrm_rm]; + else if (mode == X86EMUL_MODE_PROT64) + rip_relative = 1; + break; + default: + modrm_ea += _regs[modrm_rm]; + break; + } + switch (modrm_mod) { + case 0: + if (modrm_rm == 5) + modrm_ea += insn_fetch(s32, 4, _eip); + break; + case 1: + modrm_ea += insn_fetch(s8, 1, _eip); + break; + case 2: + modrm_ea += insn_fetch(s32, 4, _eip); + break; + } + } + if (!override_base) + override_base = &ctxt->ds_base; + if (mode == X86EMUL_MODE_PROT64 && + override_base != &ctxt->fs_base && + override_base != &ctxt->gs_base) + override_base = NULL; + + if (override_base) + modrm_ea += *override_base; + + if (rip_relative) { + modrm_ea += _eip; + switch (d & SrcMask) { + case SrcImmByte: + modrm_ea += 1; + break; + case SrcImm: + if (d & ByteOp) + modrm_ea += 1; + else + if (op_bytes == 8) + modrm_ea += 4; + else + modrm_ea += op_bytes; + } + } + if (ad_bytes != 8) + modrm_ea = (u32)modrm_ea; + cr2 = modrm_ea; + modrm_done: + ; + } + + /* Decode and fetch the destination operand: register or memory. */ + switch (d & DstMask) { + case ImplicitOps: + /* Special instructions do their own operand decoding. */ + goto special_insn; + case DstReg: + dst.type = OP_REG; + if ((d & ByteOp) + && !(twobyte_table && (b == 0xb6 || b == 0xb7))) { + dst.ptr = decode_register(modrm_reg, _regs, + (rex_prefix == 0)); + dst.val = *(u8 *) dst.ptr; + dst.bytes = 1; + } else { + dst.ptr = decode_register(modrm_reg, _regs, 0); + switch ((dst.bytes = op_bytes)) { + case 2: + dst.val = *(u16 *)dst.ptr; + break; + case 4: + dst.val = *(u32 *)dst.ptr; + break; + case 8: + dst.val = *(u64 *)dst.ptr; + break; + } + } + break; + case DstMem: + dst.type = OP_MEM; + dst.ptr = (unsigned long *)cr2; + dst.bytes = (d & ByteOp) ? 1 : op_bytes; + if (!(d & Mov) && /* optimisation - avoid slow emulated read */ + ((rc = ops->read_emulated((unsigned long)dst.ptr, + &dst.val, dst.bytes, ctxt)) != 0)) + goto done; + break; + } + dst.orig_val = dst.val; + + /* + * Decode and fetch the source operand: register, memory + * or immediate. + */ + switch (d & SrcMask) { + case SrcNone: + break; + case SrcReg: + src.type = OP_REG; + if (d & ByteOp) { + src.ptr = decode_register(modrm_reg, _regs, + (rex_prefix == 0)); + src.val = src.orig_val = *(u8 *) src.ptr; + src.bytes = 1; + } else { + src.ptr = decode_register(modrm_reg, _regs, 0); + switch ((src.bytes = op_bytes)) { + case 2: + src.val = src.orig_val = *(u16 *) src.ptr; + break; + case 4: + src.val = src.orig_val = *(u32 *) src.ptr; + break; + case 8: + src.val = src.orig_val = *(u64 *) src.ptr; + break; + } + } + break; + case SrcMem16: + src.bytes = 2; + goto srcmem_common; + case SrcMem32: + src.bytes = 4; + goto srcmem_common; + case SrcMem: + src.bytes = (d & ByteOp) ? 1 : op_bytes; + srcmem_common: + src.type = OP_MEM; + src.ptr = (unsigned long *)cr2; + if ((rc = ops->read_emulated((unsigned long)src.ptr, + &src.val, src.bytes, ctxt)) != 0) + goto done; + src.orig_val = src.val; + break; + case SrcImm: + src.type = OP_IMM; + src.ptr = (unsigned long *)_eip; + src.bytes = (d & ByteOp) ? 1 : op_bytes; + if (src.bytes == 8) + src.bytes = 4; + /* NB. Immediates are sign-extended as necessary. */ + switch (src.bytes) { + case 1: + src.val = insn_fetch(s8, 1, _eip); + break; + case 2: + src.val = insn_fetch(s16, 2, _eip); + break; + case 4: + src.val = insn_fetch(s32, 4, _eip); + break; + } + break; + case SrcImmByte: + src.type = OP_IMM; + src.ptr = (unsigned long *)_eip; + src.bytes = 1; + src.val = insn_fetch(s8, 1, _eip); + break; + } + + if (twobyte) + goto twobyte_insn; + + switch (b) { + case 0x00 ... 0x05: + add: /* add */ + emulate_2op_SrcV("add", src, dst, _eflags); + break; + case 0x08 ... 0x0d: + or: /* or */ + emulate_2op_SrcV("or", src, dst, _eflags); + break; + case 0x10 ... 0x15: + adc: /* adc */ + emulate_2op_SrcV("adc", src, dst, _eflags); + break; + case 0x18 ... 0x1d: + sbb: /* sbb */ + emulate_2op_SrcV("sbb", src, dst, _eflags); + break; + case 0x20 ... 0x25: + and: /* and */ + emulate_2op_SrcV("and", src, dst, _eflags); + break; + case 0x28 ... 0x2d: + sub: /* sub */ + emulate_2op_SrcV("sub", src, dst, _eflags); + break; + case 0x30 ... 0x35: + xor: /* xor */ + emulate_2op_SrcV("xor", src, dst, _eflags); + break; + case 0x38 ... 0x3d: + cmp: /* cmp */ + emulate_2op_SrcV("cmp", src, dst, _eflags); + break; + case 0x63: /* movsxd */ + if (mode != X86EMUL_MODE_PROT64) + goto cannot_emulate; + dst.val = (s32) src.val; + break; + case 0x80 ... 0x83: /* Grp1 */ + switch (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: + test: /* test */ + emulate_2op_SrcV("test", src, dst, _eflags); + break; + case 0x86 ... 0x87: /* xchg */ + /* Write back the register source. */ + switch (dst.bytes) { + case 1: + *(u8 *) src.ptr = (u8) dst.val; + break; + case 2: + *(u16 *) src.ptr = (u16) dst.val; + break; + case 4: + *src.ptr = (u32) dst.val; + break; /* 64b reg: zero-extend */ + case 8: + *src.ptr = dst.val; + break; + } + /* + * Write back the memory destination with implicit LOCK + * prefix. + */ + dst.val = src.val; + lock_prefix = 1; + break; + case 0xa0 ... 0xa1: /* mov */ + dst.ptr = (unsigned long *)&_regs[VCPU_REGS_RAX]; + dst.val = src.val; + _eip += ad_bytes; /* skip src displacement */ + break; + case 0xa2 ... 0xa3: /* mov */ + dst.val = (unsigned long)_regs[VCPU_REGS_RAX]; + _eip += ad_bytes; /* skip dst displacement */ + break; + case 0x88 ... 0x8b: /* mov */ + case 0xc6 ... 0xc7: /* mov (sole member of Grp11) */ + dst.val = src.val; + break; + case 0x8f: /* pop (sole member of Grp1a) */ + /* 64-bit mode: POP always pops a 64-bit operand. */ + if (mode == X86EMUL_MODE_PROT64) + dst.bytes = 8; + if ((rc = ops->read_std(register_address(ctxt->ss_base, + _regs[VCPU_REGS_RSP]), + &dst.val, dst.bytes, ctxt)) != 0) + goto done; + register_address_increment(_regs[VCPU_REGS_RSP], dst.bytes); + break; + case 0xc0 ... 0xc1: + grp2: /* Grp2 */ + switch (modrm_reg) { + case 0: /* rol */ + emulate_2op_SrcB("rol", src, dst, _eflags); + break; + case 1: /* ror */ + emulate_2op_SrcB("ror", src, dst, _eflags); + break; + case 2: /* rcl */ + emulate_2op_SrcB("rcl", src, dst, _eflags); + break; + case 3: /* rcr */ + emulate_2op_SrcB("rcr", src, dst, _eflags); + break; + case 4: /* sal/shl */ + case 6: /* sal/shl */ + emulate_2op_SrcB("sal", src, dst, _eflags); + break; + case 5: /* shr */ + emulate_2op_SrcB("shr", src, dst, _eflags); + break; + case 7: /* sar */ + emulate_2op_SrcB("sar", src, dst, _eflags); + break; + } + break; + case 0xd0 ... 0xd1: /* Grp2 */ + src.val = 1; + goto grp2; + case 0xd2 ... 0xd3: /* Grp2 */ + src.val = _regs[VCPU_REGS_RCX]; + goto grp2; + case 0xf6 ... 0xf7: /* Grp3 */ + switch (modrm_reg) { + case 0 ... 1: /* test */ + /* + * Special case in Grp3: test has an immediate + * source operand. + */ + src.type = OP_IMM; + src.ptr = (unsigned long *)_eip; + src.bytes = (d & ByteOp) ? 1 : op_bytes; + if (src.bytes == 8) + src.bytes = 4; + switch (src.bytes) { + case 1: + src.val = insn_fetch(s8, 1, _eip); + break; + case 2: + src.val = insn_fetch(s16, 2, _eip); + break; + case 4: + src.val = insn_fetch(s32, 4, _eip); + break; + } + goto test; + case 2: /* not */ + dst.val = ~dst.val; + break; + case 3: /* neg */ + emulate_1op("neg", dst, _eflags); + break; + default: + goto cannot_emulate; + } + break; + case 0xfe ... 0xff: /* Grp4/Grp5 */ + switch (modrm_reg) { + case 0: /* inc */ + emulate_1op("inc", dst, _eflags); + break; + case 1: /* dec */ + emulate_1op("dec", dst, _eflags); + break; + case 6: /* push */ + /* 64-bit mode: PUSH always pushes a 64-bit operand. */ + if (mode == X86EMUL_MODE_PROT64) { + dst.bytes = 8; + if ((rc = ops->read_std((unsigned long)dst.ptr, + &dst.val, 8, + ctxt)) != 0) + goto done; + } + register_address_increment(_regs[VCPU_REGS_RSP], + -dst.bytes); + if ((rc = ops->write_std( + register_address(ctxt->ss_base, + _regs[VCPU_REGS_RSP]), + dst.val, dst.bytes, ctxt)) != 0) + goto done; + dst.val = dst.orig_val; /* skanky: disable writeback */ + break; + default: + goto cannot_emulate; + } + break; + } + +writeback: + if ((d & Mov) || (dst.orig_val != dst.val)) { + switch (dst.type) { + case OP_REG: + /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */ + switch (dst.bytes) { + case 1: + *(u8 *)dst.ptr = (u8)dst.val; + break; + case 2: + *(u16 *)dst.ptr = (u16)dst.val; + break; + case 4: + *dst.ptr = (u32)dst.val; + break; /* 64b: zero-ext */ + case 8: + *dst.ptr = dst.val; + break; + } + break; + case OP_MEM: + if (lock_prefix) + rc = ops->cmpxchg_emulated((unsigned long)dst. + ptr, dst.orig_val, + dst.val, dst.bytes, + ctxt); + else + rc = ops->write_emulated((unsigned long)dst.ptr, + dst.val, dst.bytes, + ctxt); + if (rc != 0) + goto done; + default: + break; + } + } + + /* Commit shadow register state. */ + memcpy(ctxt->vcpu->regs, _regs, sizeof _regs); + ctxt->eflags = _eflags; + ctxt->vcpu->rip = _eip; + +done: + return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; + +special_insn: + if (twobyte) + goto twobyte_special_insn; + if (rep_prefix) { + if (_regs[VCPU_REGS_RCX] == 0) { + ctxt->vcpu->rip = _eip; + goto done; + } + _regs[VCPU_REGS_RCX]--; + _eip = ctxt->vcpu->rip; + } + switch (b) { + case 0xa4 ... 0xa5: /* movs */ + dst.type = OP_MEM; + dst.bytes = (d & ByteOp) ? 1 : op_bytes; + dst.ptr = (unsigned long *)register_address(ctxt->es_base, + _regs[VCPU_REGS_RDI]); + if ((rc = ops->read_emulated(register_address( + override_base ? *override_base : ctxt->ds_base, + _regs[VCPU_REGS_RSI]), &dst.val, dst.bytes, ctxt)) != 0) + goto done; + register_address_increment(_regs[VCPU_REGS_RSI], + (_eflags & EFLG_DF) ? -dst.bytes : dst.bytes); + register_address_increment(_regs[VCPU_REGS_RDI], + (_eflags & EFLG_DF) ? -dst.bytes : dst.bytes); + break; + case 0xa6 ... 0xa7: /* cmps */ + DPRINTF("Urk! I don't handle CMPS.\n"); + goto cannot_emulate; + case 0xaa ... 0xab: /* stos */ + dst.type = OP_MEM; + dst.bytes = (d & ByteOp) ? 1 : op_bytes; + dst.ptr = (unsigned long *)cr2; + dst.val = _regs[VCPU_REGS_RAX]; + register_address_increment(_regs[VCPU_REGS_RDI], + (_eflags & EFLG_DF) ? -dst.bytes : dst.bytes); + break; + case 0xac ... 0xad: /* lods */ + dst.type = OP_REG; + dst.bytes = (d & ByteOp) ? 1 : op_bytes; + dst.ptr = (unsigned long *)&_regs[VCPU_REGS_RAX]; + if ((rc = ops->read_emulated(cr2, &dst.val, dst.bytes, ctxt)) != 0) + goto done; + register_address_increment(_regs[VCPU_REGS_RSI], + (_eflags & EFLG_DF) ? -dst.bytes : dst.bytes); + break; + case 0xae ... 0xaf: /* scas */ + DPRINTF("Urk! I don't handle SCAS.\n"); + goto cannot_emulate; + } + goto writeback; + +twobyte_insn: + switch (b) { + case 0x01: /* lgdt, lidt, lmsw */ + switch (modrm_reg) { + u16 size; + unsigned long address; + + case 2: /* lgdt */ + rc = read_descriptor(ctxt, ops, src.ptr, + &size, &address, op_bytes); + if (rc) + goto done; + realmode_lgdt(ctxt->vcpu, size, address); + break; + case 3: /* lidt */ + rc = read_descriptor(ctxt, ops, src.ptr, + &size, &address, op_bytes); + if (rc) + goto done; + realmode_lidt(ctxt->vcpu, size, address); + break; + case 4: /* smsw */ + if (modrm_mod != 3) + goto cannot_emulate; + *(u16 *)&_regs[modrm_rm] + = realmode_get_cr(ctxt->vcpu, 0); + break; + case 6: /* lmsw */ + if (modrm_mod != 3) + goto cannot_emulate; + realmode_lmsw(ctxt->vcpu, (u16)modrm_val, &_eflags); + break; + case 7: /* invlpg*/ + emulate_invlpg(ctxt->vcpu, cr2); + break; + default: + goto cannot_emulate; + } + break; + case 0x21: /* mov from dr to reg */ + if (modrm_mod != 3) + goto cannot_emulate; + rc = emulator_get_dr(ctxt, modrm_reg, &_regs[modrm_rm]); + break; + case 0x23: /* mov from reg to dr */ + if (modrm_mod != 3) + goto cannot_emulate; + rc = emulator_set_dr(ctxt, modrm_reg, _regs[modrm_rm]); + break; + case 0x40 ... 0x4f: /* cmov */ + dst.val = dst.orig_val = src.val; + d &= ~Mov; /* default to no move */ + /* + * First, assume we're decoding an even cmov opcode + * (lsb == 0). + */ + switch ((b & 15) >> 1) { + case 0: /* cmovo */ + d |= (_eflags & EFLG_OF) ? Mov : 0; + break; + case 1: /* cmovb/cmovc/cmovnae */ + d |= (_eflags & EFLG_CF) ? Mov : 0; + break; + case 2: /* cmovz/cmove */ + d |= (_eflags & EFLG_ZF) ? Mov : 0; + break; + case 3: /* cmovbe/cmovna */ + d |= (_eflags & (EFLG_CF | EFLG_ZF)) ? Mov : 0; + break; + case 4: /* cmovs */ + d |= (_eflags & EFLG_SF) ? Mov : 0; + break; + case 5: /* cmovp/cmovpe */ + d |= (_eflags & EFLG_PF) ? Mov : 0; + break; + case 7: /* cmovle/cmovng */ + d |= (_eflags & EFLG_ZF) ? Mov : 0; + /* fall through */ + case 6: /* cmovl/cmovnge */ + d |= (!(_eflags & EFLG_SF) != + !(_eflags & EFLG_OF)) ? Mov : 0; + break; + } + /* Odd cmov opcodes (lsb == 1) have inverted sense. */ + d ^= (b & 1) ? Mov : 0; + break; + case 0xb0 ... 0xb1: /* cmpxchg */ + /* + * Save real source value, then compare EAX against + * destination. + */ + src.orig_val = src.val; + src.val = _regs[VCPU_REGS_RAX]; + emulate_2op_SrcV("cmp", src, dst, _eflags); + /* Always write back. The question is: where to? */ + d |= Mov; + if (_eflags & EFLG_ZF) { + /* Success: write back to memory. */ + dst.val = src.orig_val; + } else { + /* Failure: write the value we saw to EAX. */ + dst.type = OP_REG; + dst.ptr = (unsigned long *)&_regs[VCPU_REGS_RAX]; + } + break; + case 0xa3: + bt: /* bt */ + src.val &= (dst.bytes << 3) - 1; /* only subword offset */ + emulate_2op_SrcV_nobyte("bt", src, dst, _eflags); + break; + case 0xb3: + btr: /* btr */ + src.val &= (dst.bytes << 3) - 1; /* only subword offset */ + emulate_2op_SrcV_nobyte("btr", src, dst, _eflags); + break; + case 0xab: + bts: /* bts */ + src.val &= (dst.bytes << 3) - 1; /* only subword offset */ + emulate_2op_SrcV_nobyte("bts", src, dst, _eflags); + break; + case 0xb6 ... 0xb7: /* movzx */ + dst.bytes = op_bytes; + dst.val = (d & ByteOp) ? (u8) src.val : (u16) src.val; + break; + case 0xbb: + btc: /* btc */ + src.val &= (dst.bytes << 3) - 1; /* only subword offset */ + emulate_2op_SrcV_nobyte("btc", src, dst, _eflags); + break; + case 0xba: /* Grp8 */ + switch (modrm_reg & 3) { + case 0: + goto bt; + case 1: + goto bts; + case 2: + goto btr; + case 3: + goto btc; + } + break; + case 0xbe ... 0xbf: /* movsx */ + dst.bytes = op_bytes; + dst.val = (d & ByteOp) ? (s8) src.val : (s16) src.val; + break; + } + goto writeback; + +twobyte_special_insn: + /* Disable writeback. */ + dst.orig_val = dst.val; + switch (b) { + case 0x0d: /* GrpP (prefetch) */ + case 0x18: /* Grp16 (prefetch/nop) */ + break; + case 0x06: + emulate_clts(ctxt->vcpu); + break; + case 0x20: /* mov cr, reg */ + if (modrm_mod != 3) + goto cannot_emulate; + _regs[modrm_rm] = realmode_get_cr(ctxt->vcpu, modrm_reg); + break; + case 0x22: /* mov reg, cr */ + if (modrm_mod != 3) + goto cannot_emulate; + realmode_set_cr(ctxt->vcpu, modrm_reg, modrm_val, &_eflags); + break; + case 0xc7: /* Grp9 (cmpxchg8b) */ +#if defined(__i386__) + { + unsigned long old_lo, old_hi; + if (((rc = ops->read_emulated(cr2 + 0, &old_lo, 4, + ctxt)) != 0) + || ((rc = ops->read_emulated(cr2 + 4, &old_hi, 4, + ctxt)) != 0)) + goto done; + if ((old_lo != _regs[VCPU_REGS_RAX]) + || (old_hi != _regs[VCPU_REGS_RDI])) { + _regs[VCPU_REGS_RAX] = old_lo; + _regs[VCPU_REGS_RDX] = old_hi; + _eflags &= ~EFLG_ZF; + } else if (ops->cmpxchg8b_emulated == NULL) { + rc = X86EMUL_UNHANDLEABLE; + goto done; + } else { + if ((rc = ops->cmpxchg8b_emulated(cr2, old_lo, + old_hi, + _regs[VCPU_REGS_RBX], + _regs[VCPU_REGS_RCX], + ctxt)) != 0) + goto done; + _eflags |= EFLG_ZF; + } + break; + } +#elif defined(__x86_64__) + { + unsigned long old, new; + if ((rc = ops->read_emulated(cr2, &old, 8, ctxt)) != 0) + goto done; + if (((u32) (old >> 0) != (u32) _regs[VCPU_REGS_RAX]) || + ((u32) (old >> 32) != (u32) _regs[VCPU_REGS_RDX])) { + _regs[VCPU_REGS_RAX] = (u32) (old >> 0); + _regs[VCPU_REGS_RDX] = (u32) (old >> 32); + _eflags &= ~EFLG_ZF; + } else { + new = (_regs[VCPU_REGS_RCX] << 32) | (u32) _regs[VCPU_REGS_RBX]; + if ((rc = ops->cmpxchg_emulated(cr2, old, + new, 8, ctxt)) != 0) + goto done; + _eflags |= EFLG_ZF; + } + break; + } +#endif + } + goto writeback; + +cannot_emulate: + DPRINTF("Cannot emulate %02x\n", b); + return -1; +} + +#ifdef __XEN__ + +#include <asm/mm.h> +#include <asm/uaccess.h> + +int +x86_emulate_read_std(unsigned long addr, + unsigned long *val, + unsigned int bytes, struct x86_emulate_ctxt *ctxt) +{ + unsigned int rc; + + *val = 0; + + if ((rc = copy_from_user((void *)val, (void *)addr, bytes)) != 0) { + propagate_page_fault(addr + bytes - rc, 0); /* read fault */ + return X86EMUL_PROPAGATE_FAULT; + } + + return X86EMUL_CONTINUE; +} + +int +x86_emulate_write_std(unsigned long addr, + unsigned long val, + unsigned int bytes, struct x86_emulate_ctxt *ctxt) +{ + unsigned int rc; + + if ((rc = copy_to_user((void *)addr, (void *)&val, bytes)) != 0) { + propagate_page_fault(addr + bytes - rc, PGERR_write_access); + return X86EMUL_PROPAGATE_FAULT; + } + + return X86EMUL_CONTINUE; +} + +#endif |