Re: PVHVM drivers in upstream linux kernel

[Juergen Gross <jgross@suse.com>]

On 12/02/2014 03:09 PM, David Vrabel wrote:
> On 02/12/14 13:00, Juergen Gross wrote:
>>
>> I'd see:
>> - XEN_PV (selects PARAVIRT, XEN_FRONTEND): be able to run as pv-domain
>>    (x86 only)
>
> Depends on PARAVIRT perhaps?

Chicken and egg problem? :-)

I'd say select, as PARAVIRT isn't a primary function the user wants to
enable, it is a prerequisite for e.g. XEN_PV.

>
>> - XEN_PVHVM (selects XEN_FRONTEND): be able to run as hvm-domain with
>>    pv-drivers
>> - XEN_BACKEND (selects PARAVIRT if x86): be able to run as driver domain
>>    (dom0 or other)
>
> Does not need to select PARAVIRT -- HVM domains can run backends.

Okay.

>
>> - XEN_DOM0 (selects PARAVIRT if x86, XEN_BACKEND): be able to run as
>>    dom0
>
> XEN_DOM0 depends on XEN_PV or XEN_PVH (if x86) and whatever ARM needs.

I've removed XEN_PV as XEN_DOM0 shouldn't require XEN_FRONTEND.
We can add XEN_PARAVIRT instead which will be needed by XEN_DOM0 and
XEN_PV and will select PARAVIRT.

>
>> - XEN_FRONTEND: be able to run as domU with pv-drivers
>
> It may also be interesting to consider splitting the PV MMU stuff under
> a PARAVIRT_MMU option.  This might address a reason why people want to
> disable PARAVIRT completely.

Okay, seems sensible. Especially regarding XEN_PVH which I've omitted
here.

I'll try to assemble a complete config tree for review before starting
with patches. :-)


Juergen