From 08ece5bb2312b4510b161a6ef6682f37f4eac8a1 Mon Sep 17 00:00:00 2001 From: Zoltan Kiss Date: Thu, 23 Jan 2014 21:23:44 +0000 Subject: xen/grant-table: Avoid m2p_override during mapping The grant mapping API does m2p_override unnecessarily: only gntdev needs it, for blkback and future netback patches it just cause a lock contention, as those pages never go to userspace. Therefore this series does the following: - the original functions were renamed to __gnttab_[un]map_refs, with a new parameter m2p_override - based on m2p_override either they follow the original behaviour, or just set the private flag and call set_phys_to_machine - gnttab_[un]map_refs are now a wrapper to call __gnttab_[un]map_refs with m2p_override false - a new function gnttab_[un]map_refs_userspace provides the old behaviour It also removes a stray space from page.h and change ret to 0 if XENFEAT_auto_translated_physmap, as that is the only possible return value there. v2: - move the storing of the old mfn in page->index to gnttab_map_refs - move the function header update to a separate patch v3: - a new approach to retain old behaviour where it needed - squash the patches into one v4: - move out the common bits from m2p* functions, and pass pfn/mfn as parameter - clear page->private before doing anything with the page, so m2p_find_override won't race with this v5: - change return value handling in __gnttab_[un]map_refs - remove a stray space in page.h - add detail why ret = 0 now at some places v6: - don't pass pfn to m2p* functions, just get it locally Signed-off-by: Zoltan Kiss Suggested-by: David Vrabel Acked-by: David Vrabel Acked-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk --- include/xen/grant_table.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'include/xen/grant_table.h') diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index a5af2a26d94f..7ad033dbc845 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -191,11 +191,15 @@ void gnttab_free_auto_xlat_frames(void); #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, - struct gnttab_map_grant_ref *kmap_ops, struct page **pages, unsigned int count); +int gnttab_map_refs_userspace(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count); int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, - struct gnttab_map_grant_ref *kunmap_ops, struct page **pages, unsigned int count); +int gnttab_unmap_refs_userspace(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_map_grant_ref *kunmap_ops, + struct page **pages, unsigned int count); /* Perform a batch of grant map/copy operations. Retry every batch slot * for which the hypervisor returns GNTST_eagain. This is typically due -- cgit v1.2.3