Use a catchall case for all reasons that we do not handle, and
move the vCPU run switch into its own function.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Based on the Firecracker devices crate from commit 9cdb5b2.
It is a trimmed down version compared to the Firecracker one, to remove
a bunch of pulled dependencies (logger, metrics, rate limiter, etc...).
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
