Re: [PATCH v3] docs: add PVH specification

["Roger Pau Monné" <roger.pau@citrix.com>]

El 26/09/14 a les 2.00, Mukesh Rathor ha escrit:
> On Tue, 23 Sep 2014 14:16:46 +0100
> "Jan Beulich" <JBeulich@suse.com> wrote:
> 
>>>>> On 23.09.14 at 02:38, <mukesh.rathor@oracle.com> wrote:
>>> On Thu, 18 Sep 2014 19:19:24 +0200
>>> Roger Pau Monne <roger.pau@citrix.com> wrote:
>>>
>>>> Introduce a document that describes the interfaces used on PVH.
>>>> This document has been designed from a guest OS point of view
>>>> (i.e.: what a guest needs to do in order to support PVH).
>>> ..... 
>>>> +
>>>> +*TODO*: we need to figure out what to do with MMIO regions, right
>>>> now Xen +sets all the holes in the native e820 to MMIO regions for
>>>> Dom0 up to 4GB. We +need to decide what to do with MMIO regions
>>>> above 4GB on Dom0, and what to do +for PVH DomUs with
>>>> pci-passthrough.
>>>
>>> My previous comment in earlier version on this:
>>>
>>> "We map all non-ram regions for dom0 1:1 till the highest non-ram
>>> e820 entry. If there is anything that is beyond the last e820 entry,
>>> it will remain unmapped."
>>
>> But that's something that needs fixing rather than spelling out in
>> the documentation. I.e. Roger having this as a TODO seems quite
>> right to me.
> 
> Yes, but what Roger is saying implies we don't map above 4GB which
> is incorrect. Perhaps:
> 
> We map all non-ram regions for dom0 1:1 till the last e820 entry. If the 
> last entry ends below 4GB, then the remaining space is mapped 1:1 upto 4GB.
> This implies that if there is any region beyond the last e820 entry above
> 4GB, it is not mapped.  
> TODO: Map region beyond last e820 if it's above 4GB. Add support for domUs
> with pci passthru.

The document has already been committed, could you please send a patch
against it to clarify this section?

Roger.