Re: [Qemu-devel] [RFC PATCH 18/34] hyperv: add support for KVM_HYPERV_EVENTFD

[Roman Kagan]

On Wed, Feb 07, 2018 at 12:01:41PM +0100, Paolo Bonzini wrote:
> On 06/02/2018 21:30, Roman Kagan wrote:
> > When setting up a notifier for Hyper-V event connection, attempt to use
> > the KVM-assisted one first, and fall back to userspace handling of the
> > hypercall if the kernel doesn't provide the requested feature.
> > 
> > Signed-off-by: Roman Kagan <address@hidden>
> 
> As before, I wouldn't mind dropping userspace SIGNAL_EVENT altogether.

That would mean not allowing vmbus stuff on a range of otherwise usable
kernels, including 4.14 which AFAIK has been declared LTS.
Note that HYPERV_EVENTFD hasn't even landed in the mainline kernel yet
(with any luck it'll make 4.16).

> It would probably end up in bitrot.

Like every compatibilty code...

Thanks,
Roman.