[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] Re: Next steps with pv_ops for Xen



Keir Fraser wrote:
You'd need to track pte->grant_handle mappings somewhere, but it could
certainly be done this way, yes.

At the moment, blktap and gntdev provide struct pages to get_user_pages by smuggling them in the vm_private_data field of the relevant vm_area_struct. Could we use this field to get the handles to ptep_get_and_clear_full as well?

Only downside that I can see is that we would need to find the vma for each PTE that needs to be cleared this way (since we don't get this passed to ptep_get_and_clear_full), but this is mitigated by (i) it only happening in the erroneous, unclean-shutdown case, and (ii) getting a hit in the mm->mmap_cache for consecutive runs of mapped grants.

Regards,

Derek.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.