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authorJennifer Herbert <jennifer.herbert@citrix.com>2014-12-24 14:03:16 +0000
committerDavid Vrabel <david.vrabel@citrix.com>2015-01-28 14:03:11 +0000
commit0ae65f49af64d68f0daca37b83383115cae5e690 (patch)
tree9c55a3b138a4f3fcccf1b6b6c7ab82c16ca699e4 /arch/x86/xen
parent0bb599fd30108883b00c7d4a226eeb49111e6932 (diff)
x86/xen: require ballooned pages for grant maps
Ballooned pages are always used for grant maps which means the original frame does not need to be saved in page->index nor restored after the grant unmap. This allows the workaround in netback for the conflicting use of the (unionized) page->index and page->pfmemalloc to be removed. Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'arch/x86/xen')
-rw-r--r--arch/x86/xen/p2m.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index c9bc53f64359..a8691cb08420 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -682,9 +682,10 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
pfn = page_to_pfn(pages[i]);
WARN_ON(PagePrivate(pages[i]));
+ WARN(pfn_to_mfn(pfn) != INVALID_P2M_ENTRY, "page must be ballooned");
+
SetPagePrivate(pages[i]);
set_page_private(pages[i], mfn);
- pages[i]->index = pfn_to_mfn(pfn);
if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
ret = -ENOMEM;
@@ -718,7 +719,7 @@ int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
set_page_private(pages[i], INVALID_P2M_ENTRY);
WARN_ON(!PagePrivate(pages[i]));
ClearPagePrivate(pages[i]);
- set_phys_to_machine(pfn, pages[i]->index);
+ set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
if (kunmap_ops)
ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,