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>
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index c9bc53f..a8691cb 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -682,9 +682,10 @@
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 @@
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,
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 908e65e..6441318 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1241,12 +1241,6 @@
/* Take an extra reference to offset network stack's put_page */
get_page(queue->mmap_pages[pending_idx]);
}
- /* FIXME: __skb_fill_page_desc set this to true because page->pfmemalloc
- * overlaps with "index", and "mapping" is not set. I think mapping
- * should be set. If delivered to local stack, it would drop this
- * skb in sk_filter unless the socket has the right to use it.
- */
- skb->pfmemalloc = false;
}
static int xenvif_get_extras(struct xenvif_queue *queue,