I just a download Ubuntu 18.04.1 disk image to run off of Virtual Box, and whenever I start the VM it gives me the message "spectre v2 mitigation: lfence not serializing. switching to generic retpoline". After this it runs a trace and then stops. I'm not sure what to do about this. The other blog posts I saw where people had this issue were due to older GPU hardware (I'm running an Nvidia GTX 1060, so I wouldn't consider that too old) or because they were using an older version of Ubuntu. As far as I know, 18.04.1 is the latest version. Anyone know why this is happening?