From 0ae65f49af64d68f0daca37b83383115cae5e690 Mon Sep 17 00:00:00 2001 From: Jennifer Herbert Date: Wed, 24 Dec 2014 14:03:16 +0000 Subject: 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 Reviewed-by: Stefano Stabellini Signed-off-by: David Vrabel --- arch/x86/xen/p2m.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/x86/xen/p2m.c') 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, -- cgit v1.2.3