The goal for cloud-hypervisor is to keep the host safe. With this in
mind, we want to emulate as much as possible in userspace instead of
in kernel directly.
The IOAPIC is a good candidate to move from kernel to userspace, which
is why this commit introduces a userspace implementation of the IOAPIC
82093AA based on the documentation:
https://pdos.csail.mit.edu/6.828/2016/readings/ia32/ioapic.pdf
This code is inspired from the files devices/src/ioapic.rs and
devices/src/split_irqchip_common.rs from the crosvm codebase. The
reference version used being 6c1e23eee3065b3f3d6fc4fb992ac9884dbabf68.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@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>