KVM: x86 emulator: emulate RETF imm

Opcode CA

This gets used by a DOS based NetWare guest.

Signed-off-by: Bruce Rogers <brogers@suse.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 2bc1e81045b0..ddc3f3d2afdb 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2025,6 +2025,17 @@ static int em_ret_far(struct x86_emulate_ctxt *ctxt)
         return rc;
 }
 
+static int em_ret_far_imm(struct x86_emulate_ctxt *ctxt)
+{
+        int rc;
+
+        rc = em_ret_far(ctxt);
+        if (rc != X86EMUL_CONTINUE)
+                return rc;
+        rsp_increment(ctxt, ctxt->src.val);
+        return X86EMUL_CONTINUE;
+}
+
 static int em_cmpxchg(struct x86_emulate_ctxt *ctxt)
 {
         /* Save real source value, then compare EAX against destination. */
@@ -3763,7 +3774,8 @@ static const struct opcode opcode_table[256] = {
         G(ByteOp, group11), G(0, group11),
         /* 0xC8 - 0xCF */
         I(Stack | SrcImmU16 | Src2ImmByte, em_enter), I(Stack, em_leave),
-        N, I(ImplicitOps | Stack, em_ret_far),
+        I(ImplicitOps | Stack | SrcImmU16, em_ret_far_imm),
+        I(ImplicitOps | Stack, em_ret_far),
         D(ImplicitOps), DI(SrcImmByte, intn),
         D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret),
         /* 0xD0 - 0xD7 */