KVM: x86 emulator: implement MMX MOVQ (opcodes 0f 6f, 0f 7f)

Needed by some framebuffer drivers.  See

https://bugzilla.kernel.org/show_bug.cgi?id=42779

Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 19aec76..5997513 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2929,6 +2929,12 @@
 	return X86EMUL_CONTINUE;
 }
 
+static int em_movq(struct x86_emulate_ctxt *ctxt)
+{
+	ctxt->dst.mm_val = ctxt->src.mm_val;
+	return X86EMUL_CONTINUE;
+}
+
 static int em_invlpg(struct x86_emulate_ctxt *ctxt)
 {
 	int rc;
@@ -3468,7 +3474,7 @@
 };
 
 static struct gprefix pfx_0f_6f_0f_7f = {
-	N, N, N, I(Sse, em_movdqu),
+	I(Mmx, em_movq), N, N, I(Sse, em_movdqu),
 };
 
 static struct opcode opcode_table[256] = {