Even the cheapest baseband chip will add a significant cost to a phone. If they can get rid of the physical baseband processor they get a major cost savings.
As for why user a hypervisor vs a user mode or kernel driver: Modularity.
Some company can specialize in producing soft-basebands (software eats the world!) and ship a simple image blob that you can drop into your virtualization host, set it to use 5% of CPU time and you're away to the races.
Might be able to bring up a baseband on a new platform inside a day.
Even the cheapest baseband chip will add a significant cost to a phone. If they can get rid of the physical baseband processor they get a major cost savings.
As for why user a hypervisor vs a user mode or kernel driver: Modularity.
Some company can specialize in producing soft-basebands (software eats the world!) and ship a simple image blob that you can drop into your virtualization host, set it to use 5% of CPU time and you're away to the races.
Might be able to bring up a baseband on a new platform inside a day.