net/e1000: update network information when macaddr is changed in guest

If we change macaddr in guest by 'ifconfig eth0 hw ether 12:12:12:34:35:36',
the mac register of e1000 is already updated, but we don't update
network information in qemu. Therefor, the information in monitor
is wrong.

This patch updates nic info when the second part of macaddr is written.
Signed-off-by: NAmos Kong <akong@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

hw/net/e1000.c

@@ -1106,7 +1106,15 @@ mac_read_clr8(E1000State *s, int index)
 static void
 mac_writereg(E1000State *s, int index, uint32_t val)
 {
+    uint32_t macaddr[2];
+
     s->mac_reg[index] = val;
+
+    if (index == RA + 1) {
+        macaddr[0] = cpu_to_le32(s->mac_reg[RA]);
+        macaddr[1] = cpu_to_le32(s->mac_reg[RA + 1]);
+        qemu_format_nic_info_str(qemu_get_queue(s->nic), (uint8_t *)macaddr);
+    }
 }
 
 static void