diff options
author | Zoltan Kiss <zoltan.kiss@citrix.com> | 2014-01-23 16:23:44 -0500 |
---|---|---|
committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2014-01-31 09:48:32 -0500 |
commit | 08ece5bb2312b4510b161a6ef6682f37f4eac8a1 (patch) | |
tree | d331f6b82ca8f0346afdf54bc793fb10c4bdaec8 /include/xen | |
parent | 47c542050d306e50f09512eb6339dbf2fc02fddd (diff) |
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 <zoltan.kiss@citrix.com>
Suggested-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'include/xen')
-rw-r--r-- | include/xen/grant_table.h | 8 |
1 files changed, 6 insertions, 2 deletions
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); | |||
191 | #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) | 191 | #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) |
192 | 192 | ||
193 | int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, | 193 | int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, |
194 | struct gnttab_map_grant_ref *kmap_ops, | ||
195 | struct page **pages, unsigned int count); | 194 | struct page **pages, unsigned int count); |
195 | int gnttab_map_refs_userspace(struct gnttab_map_grant_ref *map_ops, | ||
196 | struct gnttab_map_grant_ref *kmap_ops, | ||
197 | struct page **pages, unsigned int count); | ||
196 | int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, | 198 | int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, |
197 | struct gnttab_map_grant_ref *kunmap_ops, | ||
198 | struct page **pages, unsigned int count); | 199 | struct page **pages, unsigned int count); |
200 | int gnttab_unmap_refs_userspace(struct gnttab_unmap_grant_ref *unmap_ops, | ||
201 | struct gnttab_map_grant_ref *kunmap_ops, | ||
202 | struct page **pages, unsigned int count); | ||
199 | 203 | ||
200 | /* Perform a batch of grant map/copy operations. Retry every batch slot | 204 | /* Perform a batch of grant map/copy operations. Retry every batch slot |
201 | * for which the hypervisor returns GNTST_eagain. This is typically due | 205 | * for which the hypervisor returns GNTST_eagain. This is typically due |