Bound checks for virtio-mem and ACPI memory hotplug are off by
one and two, respectively. This prevents users to fully use the reserved
memory hotplug size.
For ACPI, if we specific `--memory size=2G,hotplug_size=4G` and run
`ch-remote resize --memory 6G`, cloud-hypervisor will report the
following error because of the incorrect bound check:
`<vmm> ERROR:vmm/src/lib.rs:1631 -- Error when resizing VM:
MemoryManager(InsufficientHotplugRam)`
Similarly, for virtio-mem, cloud-hypervisor will fail the incorrect
bound check and abort the resize. The VM will see the following error
in dmesg:
`virtio_mem virtio3: unknown error, marking device broken: -22`
This patch has fixed both bound checks and ensure that users can
hot add memory up to the reserved hotplug size.
Signed-off-by: Yuhong Zhong <yz@cs.columbia.edu>
2ad8fac624