Re: [PATCH 2/8] x86/head: Refactor 32-bit pgtable setup

From: Boris Ostrovsky
Date: Fri Dec 02 2016 - 09:03:36 EST


On 12/02/2016 04:45 AM, Ingo Molnar wrote:
> * Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> wrote:
>
>> On 10/31/2016 08:33 AM, Boris Ostrovsky wrote:
>>>
>>> On 10/14/2016 02:05 PM, Boris Ostrovsky wrote:
>>>> From: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
>>>>
>>>> The new Xen PVH entry point requires page tables to be setup by the
>>>> kernel since it is entered with paging disabled.
>>>>
>>>> Pull the common code out of head_32.S and into pgtable_32.S so that
>>>> setup_pgtable_32 can be invoked from both the new Xen entry point and
>>>> the existing startup_32 code.
>>>
>>> Ping to x86 maintainers.
>> Pinging again.
>>
>> I will be re-sending this series at some point (it has been delayed by
>> some hypervisor changes that will be needed) but I'd like to hear from
>> x86 maintainers whether this will be acceptable before I post this again.
> Could this be done in C?

I suppose it could be, I haven't thought about it.

The goal here was to simply make existing startup code available to
others (Xen guest) without changes. Are you suggesting to build page
tables in C for the Xen guest only or to make startup_32 call new C code
as well?

-boris