Re: [PATCH 4/4 v3] KVM: Introduce kvm_memory_slot::arch and move lpage_info into it

[Avi Kivity <avi@redhat.com>]

On 03/07/2012 04:57 PM, Alexander Graf wrote:
> On 03/07/2012 03:04 PM, Avi Kivity wrote:
>> On 03/07/2012 03:27 PM, Alexander Graf wrote:
>>>> At the time I made this patch, it seemed that only kvm-x86 supported
>>>> huge pages, on ppc the array should be empty:
>>>
>>> Hrm. I suppose this refers to transparent huge pages?
>> Just huge pages.  Whether they are static or dynamic is immaterial in
>> this context.
>
> Well, book3s_hv and e500 support hugetlbfs. I've never had to touch
> that patches code though - so I guess I'm still not really
> understanding what it's there for O_o.
>

The kvm hugepage code uses large sptes to map large pages, when
available (either via hugetlbfs or transparent hugepages).  Since x86
supports swapping, and needs to write-protect pages for dirty logging
and for shadowing guest pagetables, it needs a reverse map from pages to
sptes.  The data structure we're discussing is part of the reverse map
for large pages.

-- 
error compiling committee.c: too many arguments to function