Re: pv_ops & gntdev?

[Gerd Hoffmann <kraxel@redhat.com>]

Jeremy Fitzhardinge wrote:
>> Ideas how to handle the grant unmap case?
>> I suspect the vm_ops->zap_pte() approach isn't going to fly for mainline
>> merge ...
> 
> Yes, my plan is:
> 
>   1. when installing a grant in a pte page, allocate a shadow page and
>      hang it off page->private; also set a page flag on the pgd page
>      flags (steal something spare)
>   2. store the grant handle in the slot corresponding to the pt
>   3. when clearing the pte, check to see if there's a grant handle and
>      zap it
>   4. when unpinning the pagetable, check to see if there's the "grant
>      mapping" flag in the pgd, and do a grant-zap pass before unpinning

Also: 2.6.18 gntdev does some funky interaction with the balloon driver.
 What is the point in doing so?

thanks,
  Gerd