[jparyani]

Does anyone know if Amazon ec2 instances would actually be vulnerable to this attack? For instances with dedicated cpu being promised (i.e. everything except micro), it seems reasonable that they'd be running Xen with processor affinity turned on, thereby preventing any attack exploiting L1 cache.

[ComputerGuru]

I guess the same attack could theoretically work for an L2 cache, though you'd need an exponentially larger amount of data collection to pull it off, with an even bigger margin of error?