[PATCH v2 15/26] KVM: x86 emulator: emulate LAHF

Avi Kivity
2012-06-27T15:20:03Z

Opcode 9F.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/emulate.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 5053e9e..90b549e 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3227,6 +3227,13 @@ static int em_cpuid(struct x86_emulate_ctxt *ctxt)
return X86EMUL_CONTINUE;
}

+static int em_lahf(struct x86_emulate_ctxt *ctxt)
+{
+ ctxt->regs[VCPU_REGS_RAX] &= ~0xff00UL;
+ ctxt->regs[VCPU_REGS_RAX] |= (ctxt->eflags & 0xff) << 8;
+ return X86EMUL_CONTINUE;
+}
+
static bool valid_cr(int nr)
{
switch (nr) {
@@ -3622,7 +3629,7 @@ static int check_perm_out(struct x86_emulate_ctxt *ctxt)
D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd),
I(SrcImmFAddr | No64, em_call_far), N,
II(ImplicitOps | Stack, em_pushf, pushf),
- II(ImplicitOps | Stack, em_popf, popf), N, N,
+ II(ImplicitOps | Stack, em_popf, popf), N, I(ImplicitOps, em_lahf),
/* 0xA0 - 0xA7 */
I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov),
I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov),
--
1.7.11