From 6666754b11297526c699f8df63c52d50c24fe946 Mon Sep 17 00:00:00 2001 From: Annie Li Date: Mon, 12 Dec 2011 18:14:42 +0800 Subject: xen/granttable: Support sub-page grants - They can't be used to map the page (so can only be used in a GNTTABOP_copy hypercall). - It's possible to grant access with a finer granularity than whole pages. - Xen guarantees that they can be revoked quickly (a normal map grant can only be revoked with the cooperation of the domain which has been granted access). Signed-off-by: Annie Li Signed-off-by: Konrad Rzeszutek Wilk --- include/xen/grant_table.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/xen/grant_table.h') diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index fea4954174f0..2b492b9637b3 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -62,6 +62,15 @@ int gnttab_resume(void); int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, int readonly); +int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame, + int flags, unsigned page_off, + unsigned length); + +/* + * Are sub-page grants available on this version of Xen? Returns true if they + * are, and false if they're not. + */ +bool gnttab_subpage_grants_available(void); /* * End access through the given grant reference, iff the grant entry is no @@ -108,6 +117,10 @@ void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, unsigned long frame, int readonly); +int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid, + unsigned long frame, int flags, + unsigned page_off, + unsigned length); void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, unsigned long pfn); -- cgit v1.2.3