Re: unbind xen3 frontend drivers

[Christoph Egger <Christoph_Egger%gmx.de@localhost>]

Jean-Yves Migeon wrote:
> Christoph Egger wrote:
>> Xen supports ia64 aside of x86. It allows to run
>> both HVM and PV guests.
>> HVM guests may also use PV drivers.
>>
>> In order to make PV drivers available for NetBSD
>> as HVM guest, I have to unbind the xen3 frontend
>> drivers from the PV guest only context.
>>
>> This means, I need to move the following files
>> into a seperate directory:
>>
>> if_xennet_xenbus.c
>> xbd_xenbus.c
>> xennet_checksum.c
>>
>> In my working tree, I moved them to
>> sys/arch/xen/dev
>>
>> Is this directory ok or
>> should I move them
>> to sys/dev/xen/xen and xenbus to sys/dev/xen/xenbus ?
> 
> While I am not the one who can make this decision, I prefer to have MI
> code under sys/dev/xen.
> 
> Thing is, take if_xennet_xenbus.c for example, it relies on MD
> functions, like x86 barriers and P2M translations. As a consequence, I
> am not sure that sys/dev/xen is a good candidate; it stays pretty close
> to x86, and not suitable for sys/dev/xen yet.

For there barriers, there's the MI membar_*() API.
The P2M translations would need an MI API with MD specific implementations.

Without having the P2M translations abstracted in a MI fashion,
I think, sys/arch/xen/dev is the proper place.

Christoph