4.3 also have this problem, but patch that is fixing this problem
probably will be soon merged into 4.2 and 4.3 -
> Another question: is kernel 4.2 broken with
OVMF? I thought about upgrading to 15.10 to see if the issue is
Mostly yes. It freezes on the first stages of booting with 100%
one core cpu load.
I don't remember if there are any fixes available except using
"lts" 4.1.13 or 4.3.x kernels.