I thought to jump in, as I've been using Debian on Hyper-V for quite a long while. I'm afraid my answer is not 100% relevant, as I run Hyper-V on Windows Server, but I thought to mention, especially as
Microsoft's official information is out of date.
I have had no problem with Debian 9 on Hyper-V on Windows Server 2016. I made a test install just now, just in case. Here's the quick summary:
- Generation 2, secure boot disabled, set a VLAN tag for my virtual interface but pretty much all defaults
- Netinst image with firmware (I always only keep the firmware versions on hand, not sure if it matters)
- Basic expert install, pretty much click through
- Post-install, install package hyperv-daemons
- Also I tend to edit /etc/default/grub to add kernel parameter video=hyperv_fb:800x600 just for personal convenience
The first reboot, after installing hyperv-daemons fails, it doesn't like shutting down in a timely fashion. After that, no problems.
I am familiar with Windows 10 being a bit different in detail, but I thought it worth mentioning that generally on a modern Hyper-V environment, Debian works quite well. Granted, the match of Debian and Windows isn't philosophically very harmonious, but that's our way of being able to use Debian even in an enterprise environment. Vmware has made sure to burn all their bridges our way and while Xen is wonderful in some cases, it's limited in some key features.