KVM: x86 emulator: Add std and cld instructions (opcodes 0xfc-0xfd)
This adds the std and cld instructions to the emulator.
Encountered while running the BIOS with invalid guest
state emulation enabled.
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index 66e0bd6..944f1f4 100644
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -187,7 +187,7 @@
ImplicitOps, ImplicitOps, Group | Group3_Byte, Group | Group3,
/* 0xF8 - 0xFF */
ImplicitOps, 0, ImplicitOps, ImplicitOps,
- 0, 0, Group | Group4, Group | Group5,
+ ImplicitOps, ImplicitOps, Group | Group4, Group | Group5,
};
static u16 twobyte_table[256] = {
@@ -1762,6 +1762,14 @@
ctxt->eflags |= X86_EFLAGS_IF;
c->dst.type = OP_NONE; /* Disable writeback. */
break;
+ case 0xfc: /* cld */
+ ctxt->eflags &= ~EFLG_DF;
+ c->dst.type = OP_NONE; /* Disable writeback. */
+ break;
+ case 0xfd: /* std */
+ ctxt->eflags |= EFLG_DF;
+ c->dst.type = OP_NONE; /* Disable writeback. */
+ break;
case 0xfe ... 0xff: /* Grp4/Grp5 */
rc = emulate_grp45(ctxt, ops);
if (rc != 0)