rcutorture: Add KVM-based test framework

This commit adds the test framework that I used to test RCU under KVM.
This consists of a group of scripts and Kconfig fragments.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
41 files changed