Re: [Qemu-discuss] User Behavior Tracking defenses in VMs

[bancfc]

Interesting ideas Jakob. Where can I post this as a feature request so 
it gets more attention?

N.B. My second solution suggestion is not the way to go. High precision 
timers in virtualizers have bad security implications but there is no 
way around them. They enable side-channel attacks on crypto operations 
running on other VMs as well as aid in biometric fingerprinting. A multi 
hypervisor study on timer accuracy shows most have high accuracy by 
necessity. Increasing coarseness in the hypervisor's code can lead to 
guest slow downs or instability.[1] The amount of coarseness they can 
take varies by hypervisor. CPU load does NOT affect timer accuracy [in 
KVM] however IO does.

Paper: Achieving High Resolution Timer Events in Virtualized Environment

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4503740/