On Mon, Aug 21, 2017 at 1:40 AM, Denis Plotnikov <dplotnikov@xxxxxxxxxxxxx> wrote: > ping! > I still don't feel my questions have been well answered. Its really not clear to me why, in order to allow the level-2 guest to use a vdso that the answer is to export more data through the entire stack rather then to make the kvmclock to be usable from the vsyscall. So far for a problem statement, all I've got is: "However, when using nested virtualization you have L0: bare-metal hypervisor (uses TSC) L1: nested hypervisor (uses kvmclock, can use vsyscall) L2: nested guest and L2 cannot use vsyscall because it is not using the TSC." Which is a start but doesn't really make it clear why the proposed solution is best/necessary. thanks -john