Keir Fraser wrote:
> Yes, this would work okay I suspect. Good enough as a stop-gap measure? Are
> there any other responsibilities that you acquire if you make use of
> VM_FOREIGN (in particular, how would this affect get_user_pages)?

VM_FOREIGN is already set for the gntdev VMA (mostly because it's 
directly based on the blktap code). That means that it has the array of 
page_structs in its vm_private_data, which can be used to fulfill a 
get_user_pages call. I've attached a patch based on this fix.

Regards,

Derek.