[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] [XEN] Add more instructions to the emulator.
# HG changeset patch # User kfraser@xxxxxxxxxxxxxxxxxxxxx # Date 1168012446 0 # Node ID df00f7a988211d663c254645d378e916bf30a336 # Parent 568efb79a0f6c8d3a6b8c3cb632657fc77118e42 [XEN] Add more instructions to the emulator. Fix prefix handling to ignore misplaced REX bytes and to grok both kinds of REP prefix properly. These fixes are from Jan Beulich <jbeulich@xxxxxxxxxx>. Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx> --- xen/arch/x86/x86_emulate.c | 134 ++++++++++++++++++++++++++++++++------------- 1 files changed, 96 insertions(+), 38 deletions(-) diff -r 568efb79a0f6 -r df00f7a98821 xen/arch/x86/x86_emulate.c --- a/xen/arch/x86/x86_emulate.c Fri Jan 05 15:52:58 2007 +0000 +++ b/xen/arch/x86/x86_emulate.c Fri Jan 05 15:54:06 2007 +0000 @@ -55,35 +55,35 @@ static uint8_t opcode_table[256] = { /* 0x00 - 0x07 */ ByteOp|DstMem|SrcReg|ModRM, DstMem|SrcReg|ModRM, ByteOp|DstReg|SrcMem|ModRM, DstReg|SrcMem|ModRM, - 0, 0, 0, 0, + ByteOp|DstReg|SrcImm, DstReg|SrcImm, 0, 0, /* 0x08 - 0x0F */ ByteOp|DstMem|SrcReg|ModRM, DstMem|SrcReg|ModRM, ByteOp|DstReg|SrcMem|ModRM, DstReg|SrcMem|ModRM, - 0, 0, 0, 0, + ByteOp|DstReg|SrcImm, DstReg|SrcImm, 0, 0, /* 0x10 - 0x17 */ ByteOp|DstMem|SrcReg|ModRM, DstMem|SrcReg|ModRM, ByteOp|DstReg|SrcMem|ModRM, DstReg|SrcMem|ModRM, - 0, 0, 0, 0, + ByteOp|DstReg|SrcImm, DstReg|SrcImm, 0, 0, /* 0x18 - 0x1F */ ByteOp|DstMem|SrcReg|ModRM, DstMem|SrcReg|ModRM, ByteOp|DstReg|SrcMem|ModRM, DstReg|SrcMem|ModRM, - 0, 0, 0, 0, + ByteOp|DstReg|SrcImm, DstReg|SrcImm, 0, 0, /* 0x20 - 0x27 */ ByteOp|DstMem|SrcReg|ModRM, DstMem|SrcReg|ModRM, ByteOp|DstReg|SrcMem|ModRM, DstReg|SrcMem|ModRM, - 0, 0, 0, 0, + ByteOp|DstReg|SrcImm, DstReg|SrcImm, 0, 0, /* 0x28 - 0x2F */ ByteOp|DstMem|SrcReg|ModRM, DstMem|SrcReg|ModRM, ByteOp|DstReg|SrcMem|ModRM, DstReg|SrcMem|ModRM, - 0, 0, 0, 0, + ByteOp|DstReg|SrcImm, DstReg|SrcImm, 0, 0, /* 0x30 - 0x37 */ ByteOp|DstMem|SrcReg|ModRM, DstMem|SrcReg|ModRM, ByteOp|DstReg|SrcMem|ModRM, DstReg|SrcMem|ModRM, - 0, 0, 0, 0, + ByteOp|DstReg|SrcImm, DstReg|SrcImm, 0, 0, /* 0x38 - 0x3F */ ByteOp|DstMem|SrcReg|ModRM, DstMem|SrcReg|ModRM, ByteOp|DstReg|SrcMem|ModRM, DstReg|SrcMem|ModRM, - 0, 0, 0, 0, + ByteOp|DstReg|SrcImm, DstReg|SrcImm, 0, 0, /* 0x40 - 0x4F */ ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, @@ -108,8 +108,11 @@ static uint8_t opcode_table[256] = { ByteOp|DstMem|SrcReg|ModRM|Mov, DstMem|SrcReg|ModRM|Mov, ByteOp|DstReg|SrcMem|ModRM|Mov, DstReg|SrcMem|ModRM|Mov, 0, DstReg|SrcNone|ModRM, 0, DstMem|SrcNone|ModRM|Mov, - /* 0x90 - 0x9F */ - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + /* 0x90 - 0x97 */ + ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + /* 0x98 - 0x9F */ + 0, 0, 0, 0, 0, 0, 0, 0, /* 0xA0 - 0xA7 */ ByteOp|ImplicitOps|Mov, ImplicitOps|Mov, ByteOp|ImplicitOps|Mov, ImplicitOps|Mov, @@ -134,10 +137,10 @@ static uint8_t opcode_table[256] = { 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, + 0, ImplicitOps, ByteOp|DstMem|SrcNone|ModRM, DstMem|SrcNone|ModRM, /* 0xF8 - 0xFF */ - 0, 0, 0, 0, - 0, 0, ByteOp|DstMem|SrcNone|ModRM, DstMem|SrcNone|ModRM + ImplicitOps, ImplicitOps, 0, 0, + ImplicitOps, ImplicitOps, ByteOp|DstMem|SrcNone|ModRM, DstMem|SrcNone|ModRM }; static uint8_t twobyte_table[256] = { @@ -488,7 +491,7 @@ x86_emulate( return -1; } - /* Legacy prefixes. */ + /* Prefix bytes. */ for ( i = 0; i < 8; i++ ) { switch ( b = insn_fetch_type(uint8_t) ) @@ -523,25 +526,26 @@ x86_emulate( case 0xf0: /* LOCK */ lock_prefix = 1; break; + case 0xf2: /* REPNE/REPNZ */ case 0xf3: /* REP/REPE/REPZ */ rep_prefix = 1; break; - case 0xf2: /* REPNE/REPNZ */ - break; + case 0x40 ... 0x4f: /* REX */ + if ( mode != X86EMUL_MODE_PROT64 ) + goto done_prefixes; + rex_prefix = b; + continue; default: goto done_prefixes; } + + /* Any legacy prefix after a REX prefix nullifies its effect. */ + rex_prefix = 0; } done_prefixes: - /* REX prefix. */ - if ( (mode == X86EMUL_MODE_PROT64) && ((b & 0xf0) == 0x40) ) - { - rex_prefix = b; - if ( b & 8 ) /* REX.W */ - op_bytes = 8; - b = insn_fetch_type(uint8_t); - } + if ( rex_prefix & 8 ) /* REX.W */ + op_bytes = 8; /* Opcode byte(s). */ d = opcode_table[b]; @@ -570,6 +574,7 @@ x86_emulate( if ( modrm_mod == 3 ) { + modrm_rm |= (rex_prefix & 1) << 3; ea.type = OP_REG; ea.reg = decode_register( modrm_rm, &_regs, (d & ByteOp) && (rex_prefix == 0)); @@ -812,28 +817,52 @@ x86_emulate( switch ( b ) { - case 0x00 ... 0x05: add: /* add */ + case 0x04 ... 0x05: /* add imm,%%eax */ + dst.reg = (unsigned long *)&_regs.eax; + dst.val = dst.orig_val = _regs.eax; + case 0x00 ... 0x03: add: /* add */ emulate_2op_SrcV("add", src, dst, _regs.eflags); break; - case 0x08 ... 0x0d: or: /* or */ + case 0x0c ... 0x0d: /* or imm,%%eax */ + dst.reg = (unsigned long *)&_regs.eax; + dst.val = dst.orig_val = _regs.eax; + case 0x08 ... 0x0b: or: /* or */ emulate_2op_SrcV("or", src, dst, _regs.eflags); break; - case 0x10 ... 0x15: adc: /* adc */ + case 0x14 ... 0x15: /* adc imm,%%eax */ + dst.reg = (unsigned long *)&_regs.eax; + dst.val = dst.orig_val = _regs.eax; + case 0x10 ... 0x13: adc: /* adc */ emulate_2op_SrcV("adc", src, dst, _regs.eflags); break; - case 0x18 ... 0x1d: sbb: /* sbb */ + case 0x1c ... 0x1d: /* sbb imm,%%eax */ + dst.reg = (unsigned long *)&_regs.eax; + dst.val = dst.orig_val = _regs.eax; + case 0x18 ... 0x1b: sbb: /* sbb */ emulate_2op_SrcV("sbb", src, dst, _regs.eflags); break; - case 0x20 ... 0x25: and: /* and */ + case 0x24 ... 0x25: /* and imm,%%eax */ + dst.reg = (unsigned long *)&_regs.eax; + dst.val = dst.orig_val = _regs.eax; + case 0x20 ... 0x23: and: /* and */ emulate_2op_SrcV("and", src, dst, _regs.eflags); break; - case 0x28 ... 0x2d: sub: /* sub */ + case 0x2c ... 0x2d: /* sub imm,%%eax */ + dst.reg = (unsigned long *)&_regs.eax; + dst.val = dst.orig_val = _regs.eax; + case 0x28 ... 0x2b: sub: /* sub */ emulate_2op_SrcV("sub", src, dst, _regs.eflags); break; - case 0x30 ... 0x35: xor: /* xor */ + case 0x34 ... 0x35: /* xor imm,%%eax */ + dst.reg = (unsigned long *)&_regs.eax; + dst.val = dst.orig_val = _regs.eax; + case 0x30 ... 0x33: xor: /* xor */ emulate_2op_SrcV("xor", src, dst, _regs.eflags); break; - case 0x38 ... 0x3d: cmp: /* cmp */ + case 0x3c ... 0x3d: /* cmp imm,%%eax */ + dst.reg = (unsigned long *)&_regs.eax; + dst.val = dst.orig_val = _regs.eax; + case 0x38 ... 0x3b: cmp: /* cmp */ emulate_2op_SrcV("cmp", src, dst, _regs.eflags); break; case 0x63: /* movsxd */ @@ -857,7 +886,7 @@ x86_emulate( case 0x84 ... 0x85: test: /* test */ emulate_2op_SrcV("test", src, dst, _regs.eflags); break; - case 0x86 ... 0x87: /* xchg */ + case 0x86 ... 0x87: xchg: /* xchg */ /* Write back the register source. */ switch ( dst.bytes ) { @@ -1011,6 +1040,8 @@ x86_emulate( return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; special_insn: + /* Default action: disable writeback. There may be no dest operand. */ + dst.orig_val = dst.val; if ( twobyte ) goto twobyte_special_insn; if ( rep_prefix ) @@ -1027,7 +1058,7 @@ x86_emulate( { case 0x40 ... 0x4f: /* inc/dec reg */ dst.type = OP_REG; - dst.reg = decode_register(b&7, &_regs, 0); + dst.reg = decode_register(b & 7, &_regs, 0); dst.bytes = op_bytes; dst.orig_val = dst.val = *dst.reg; if ( b & 8 ) @@ -1040,14 +1071,16 @@ x86_emulate( dst.bytes = op_bytes; if ( (mode == X86EMUL_MODE_PROT64) && (dst.bytes == 4) ) dst.bytes = 8; - dst.val = *(unsigned long *)decode_register(b&7, &_regs, 0); + dst.val = *(unsigned long *)decode_register( + (b & 7) | ((rex_prefix & 1) << 3), &_regs, 0); register_address_increment(_regs.esp, -dst.bytes); dst.mem.seg = x86_seg_ss; dst.mem.off = truncate_ea(_regs.esp); break; case 0x58 ... 0x5f: /* pop reg */ dst.type = OP_REG; - dst.reg = decode_register(b&7, &_regs, 0); + dst.reg = decode_register( + (b & 7) | ((rex_prefix & 1) << 3), &_regs, 0); dst.bytes = op_bytes; if ( (mode == X86EMUL_MODE_PROT64) && (dst.bytes == 4) ) dst.bytes = 8; @@ -1056,6 +1089,18 @@ x86_emulate( goto done; register_address_increment(_regs.esp, dst.bytes); break; + case 0x90: /* nop / xchg %%r8,%%rax */ + if ( !(rex_prefix & 1) ) + break; /* nop */ + case 0x91 ... 0x97: /* xchg reg,%%rax */ + src.type = OP_REG; + src.reg = (unsigned long *)&_regs.eax; + src.val = *src.reg; + dst.type = OP_REG; + dst.reg = decode_register( + (b & 7) | ((rex_prefix & 1) << 3), &_regs, 0); + dst.val = dst.orig_val = *dst.reg; + goto xchg; case 0xa0 ... 0xa1: /* mov mem.offs,{%al,%ax,%eax,%rax} */ /* Source EA is not encoded via ModRM. */ dst.type = OP_REG; @@ -1105,6 +1150,21 @@ x86_emulate( register_address_increment( _regs.esi, (_regs.eflags & EFLG_DF) ? -dst.bytes : dst.bytes); break; + case 0xf5: /* cmc */ + _regs.eflags ^= EFLG_CF; + break; + case 0xf8: /* clc */ + _regs.eflags &= ~EFLG_CF; + break; + case 0xf9: /* stc */ + _regs.eflags |= EFLG_CF; + break; + case 0xfc: /* cld */ + _regs.eflags &= ~EFLG_DF; + break; + case 0xfd: /* std */ + _regs.eflags |= EFLG_DF; + break; } goto writeback; @@ -1218,8 +1278,6 @@ x86_emulate( goto writeback; twobyte_special_insn: - /* Disable writeback. */ - dst.orig_val = dst.val; switch ( b ) { case 0x0d: /* GrpP (prefetch) */ _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-changelog
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