Re: xen kernel: build failure

[Keir Fraser <keir.xen@gmail.com>]

On 23/11/2011 16:31, "Jean Guyader" <jean.guyader@gmail.com> wrote:

>>> Removing the line
>>> 
>>> BUILD_BUG_ON(sizeof(*d) > PAGE_SIZE);
>>> 
>>> makes xen kernel compile again.
>> 
>> But not actually work properly. We only allocate a single page for the
>> domain struct. If the struct is bigger than a page, you'll get memory
>> corruption at run time.
>> 
> 
> Is there a reason for that? What would be the recommended to add something
> into the struct domain now if we can't make it bigger than a page.

If the thing being added is sufficiently large and self-contained, it could
be allocated separately and a pointer added to the domain struct. Else a
large logical piece of the domain struct needs to be split off. Would have
to check what would be a nice large piece -- arch.{hvm,pv} for example. Jan
might also have an opinion, as he already did some work on shrinking the
domain struct.

 -- Keir