Re: [PATCH][RFC]: pte notifiers -- support for external page tables

[Avi Kivity <avi@qumranet.com>]

[resend due to broken cc list in my original post]

Jack Steiner wrote:
> On Wed, Sep 05, 2007 at 07:38:48PM +0300, Avi Kivity wrote:
>   
> > Some hardware and software systems maintain page tables outside the normal
> > Linux page tables, which reference userspace memory.  This includes
> > Infiniband, other RDMA-capable devices, and kvm (with a pending patch).
> >
> >     
> I like it. 
>
> We have 2 special devices with external TLBs that can
> take advantage of this.
>
> One suggestion - at least for what we need. Can the notifier be
> registered against the mm_struct instead of (or in addition to) the
> vma?
>   
Yes.  It's a lot simpler since this way we don't have to support vma
creation/splitting/merging/destruction.  There's a tiny performance hit
for kvm, but it isn't worth the bother.

Will implement for v2 of this patch.

--
Any sufficiently difficult bug is indistinguishable from a feature.

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