Kernel linux-image-4.4.0-112-generic prevent the boot on Microsoft Hyper-v 2016 Gen2 VM

[giacomo]

After updating the kernel inside the virtual machine to the version 4.4.0-112-generic, at the next boot the vm will stucks during the boot at every try before bring up the network interface. An hard reset is required.
The only workaround is to set the default in grub to the previous version.
The virtual machine hardware is a Gen2.
We are experiencing this issue on all our vps with the same kernel (around 300-400 vms).
Last working version 4.4.0-109

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Joel Low (lowjoel)]

I see the same behaviour, but I'm not sure if the cause is the same, on 4.4.0-112-generic and 4.4.0-116-generic. In my case, the VM remains responsive for a variable amount of time. Sometimes it works long enough to login via SSH, at other times it does not get to the login screen. In almost all circumstances I cannot see what is wrong with the system (nothing gets printed to screen), and I see the VM use up all available CPUs. Likewise, the only way to get out of that is to do a hard reset.

Booting with 4.4.0-109 never gives this problem.

[Joel Low (lowjoel)]

I'm not sure if this is the cause or a red herring, but I found this on one of the machines which got stuck on boot. Other instances usually don't print anything.

[Joel Low (lowjoel)]

This seems to be a duplicate of https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1745349