Re: [Xen-devel] Xen PVH support in grub2

[Juergen Gross]

On 29/09/17 17:24, Roger Pau Monné wrote:
> On Fri, Sep 29, 2017 at 02:46:53PM +0000, Juergen Gross wrote:
>> I'm thinking about to add support for Xen PVH guests to grub2.
>>
>> Basically I see two options how to do it:
>>
>> a) add PVH support to current grub.xen (both, 32- and 64-bit), in
>>    order to use the same grub binary for either pv-domains or
>>    pvh-domains
>> b) create a new variant grub.xenpvh capable only to boot pvh-domains
>>
>> Are there any preferences which way to go?
> 
> IMHO, it should be possible to create a grub binary that can be loaded
> in PVH mode but that's not tied to a specific bitness. Let's avoid
> having a grub32 and grub64, that's not needed at all for PVH.

Right. OTOH we have those two variants already for PV. So the question
is whether we want grub32 and grub64 or do we want grub32, grub64 and
grub.pvh.

> Then, I also wonder whether it would make sense for this grub to load
> the kernel using the PVH entry point or the native entry point. Would
> it be possible to boot a Linux kernel up to the point where cpuid can
> be used inside of a PVH container?

I don't think today's Linux allows that. This has been discussed
very thoroughly at the time Boris added PVH V2 support to the kernel.

So my plan was to use the PVH entry point of the kernel.


Juergen