From 6e3d5dfbad4d8c29bdf8ed160f91f955f0efc12b Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Thu, 6 Dec 2007 18:14:14 +0200 Subject: [PATCH] KVM: x86 emulator: Fix stack instructions on 64-bit mode Stack instructions are always 64-bit on 64-bit mode; many of the emulated stack instructions did not take that into account. Fix by adding a 'Stack' bitflag and setting the operand size appropriately during the decode stage (except for 'push r/m', which is in a group with a few other instructions, so it gets its own treatment). This fixes random crashes on Vista x64. Signed-off-by: Avi Kivity --- drivers/kvm/x86_emulate.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c index f423b0e327f4..0a6ab06fde01 100644 --- a/drivers/kvm/x86_emulate.c +++ b/drivers/kvm/x86_emulate.c @@ -65,6 +65,7 @@ #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 */ @@ -104,14 +105,16 @@ static u16 opcode_table[256] = { /* 0x48 - 0x4F */ DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, /* 0x50 - 0x57 */ - SrcReg, SrcReg, SrcReg, SrcReg, SrcReg, SrcReg, SrcReg, SrcReg, + SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, + SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, /* 0x58 - 0x5F */ - DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, + 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, 0, + 0, 0, ImplicitOps | Mov | Stack, 0, SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps, /* insb, insw/insd */ SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps, /* outsb, outsw/outsd */ /* 0x70 - 0x77 */ @@ -128,9 +131,10 @@ static u16 opcode_table[256] = { /* 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, + 0, ModRM | DstReg, 0, DstMem | SrcNone | ModRM | Mov | Stack, /* 0x90 - 0x9F */ - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ImplicitOps, ImplicitOps, 0, 0, + 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, @@ -144,7 +148,7 @@ static u16 opcode_table[256] = { 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, 0, 0, + 0, ImplicitOps | Stack, 0, 0, ByteOp | DstMem | SrcImm | ModRM | Mov, DstMem | SrcImm | ModRM | Mov, /* 0xC8 - 0xCF */ 0, 0, 0, 0, 0, 0, 0, 0, @@ -157,7 +161,8 @@ static u16 opcode_table[256] = { /* 0xE0 - 0xE7 */ 0, 0, 0, 0, 0, 0, 0, 0, /* 0xE8 - 0xEF */ - ImplicitOps, SrcImm|ImplicitOps, 0, SrcImmByte|ImplicitOps, 0, 0, 0, 0, + ImplicitOps | Stack, SrcImm|ImplicitOps, 0, SrcImmByte|ImplicitOps, + 0, 0, 0, 0, /* 0xF0 - 0xF7 */ 0, 0, 0, 0, ImplicitOps, ImplicitOps, @@ -868,6 +873,9 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) } } + 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); @@ -988,11 +996,6 @@ static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt, struct decode_cache *c = &ctxt->decode; int rc; - /* 64-bit mode: POP always pops a 64-bit operand. */ - - if (ctxt->mode == X86EMUL_MODE_PROT64) - c->dst.bytes = 8; - rc = ops->read_std(register_address(ctxt->ss_base, c->regs[VCPU_REGS_RSP]), &c->dst.val, c->dst.bytes, ctxt->vcpu);