Re: Out-of-Process Device Emulation session at KVM Forum 2020

[Jason Wang]

On 2020/10/30 下午7:13, Stefan Hajnoczi wrote:
> > I still don't get why it must be opaque.
> If the device state format needs to be in the VMM then each device
> needs explicit enablement in each VMM (QEMU, cloud-hypervisor, etc).
>
> Let's invert the question: why does the VMM need to understand the
> device state of a_passthrough_  device?


It's not a 100% passthrough device if you want to support live 
migration. E.g the device state save and restore is not under the 
control of drivers in the guest.

And if I understand correctly, it usually requires device emulation or 
mediation in either userspace or kernel to support e.g dirty page 
tracking and other things.

Thanks