[PATCH 02/20] KVM: Implement emulation of instruction "ret" (opcode 0xc3)

Avi Kivity
2007-07-08T11:54:31Z

From: Nitin A Kamble <nitin.a.kamble-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

Signed-off-by: Nitin A Kamble <nitin.a.kamble-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/x86_emulate.c | 12 ++++++++----
1 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 46c3806..92620e4 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -131,9 +131,9 @@ static u8 opcode_table[256] = {
/* 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,
+ ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImmByte | ModRM,
+ 0, ImplicitOps, 0, 0,
+ ByteOp | DstMem | SrcImm | ModRM | Mov, DstMem | SrcImm | ModRM | Mov,
/* 0xC8 - 0xCF */
0, 0, 0, 0, 0, 0, 0, 0,
/* 0xD0 - 0xD7 */
@@ -1156,14 +1156,18 @@ special_insn:
case 0xf4: /* hlt */
ctxt->vcpu->halt_request = 1;
goto done;
+ case 0xc3: /* ret */
+ dst.ptr = &_eip;
+ goto pop_instruction;
case 0x58 ... 0x5f: /* pop reg */
dst.ptr = (unsigned long *)&_regs[b & 0x7];

+pop_instruction:
if ((rc = ops->read_std(register_address(ctxt->ss_base,
_regs[VCPU_REGS_RSP]), dst.ptr, op_bytes, ctxt)) != 0)
goto done;

- register_address_increment(_regs[VCPU_REGS_RSP], dst.bytes);
+ register_address_increment(_regs[VCPU_REGS_RSP], op_bytes);
dst.orig_val = dst.val; /* Disable writeback. */
break;
}