2018-02-26 17:41 GMT+08:00 Borislav Petkov <bp@xxxxxxxxx>: > On Mon, Feb 26, 2018 at 03:23:58PM +0800, Wanpeng Li wrote: >> From: Wanpeng Li <wanpengli@xxxxxxxxxxx> >> >> Linux (among the others) has checks to make sure that certain features >> aren't enabled on a certain family/model/stepping if the microcode version >> isn't greater than or equal to a known good version. >> >> By exposing the real microcode version, we're preventing buggy guests that > > Where do we prevent userspace from coming up with some non-sensical > microcode revision? I think it is the host admin(e.g. cloud provider)'s responsibility to set an expected microcode revision. In addition, the non-sensical value which is written by the guest will not reflect to guest-visible microcode revision and just be ignored in this implementation. Regards, Wanpeng Li
