Run Windows antrea-agent without Hyper-V

[perithompson]

Describe the problem/challenge you have
HyperV cannot run on VMs where Nested Virtualisation is disabled and Public cloud providers only offer limited support for this scenario. Having the ability to run Antrea on any windows node, regardless of the Platform is essential for wide adoption and in order for that to be true Antrea needs to be able to run without the Hyper-V dependency.

Describe the solution you'd like
The ideal solution is to change Antrea and OVS so that it uses pure HNS Networking on windows and no longer requires a VMSwitch.

Anything else you would like to add?
When running windows containers in process isolation mode HyperV is no longer required, however, Antrea requires HyperV to be installed to support Hyper-V Virtual switches. I have been able to make this work without the Hyper V hypervisor being enabled by running bcdedit /set hypervisorlaunchtype off This works for getting around running in locations where nested Hypervisors are not possible but you are not able to install Hyper-V if nested virtualisation is disabled so the image would need to be built elsewhere and added to the runtime environment.

[jayunit100]

xref, part of #331 @yasensim @ruicao93 @wenyingd

[yasensim]

Thanks for reporting this @perithompson and @jayunit100 . We plan to remove the dependency on Hyper-V. I will come back here when we have more clarity on timeline.

[ruicao93]

Thanks @perithompson and @jayunit100 , workaround works to install Hyper-V without CPU checking in doc:
#1744

Close the issue.