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authorJennifer Herbert <jennifer.herbert@citrix.com>2014-12-24 14:17:06 +0000
committerDavid Vrabel <david.vrabel@citrix.com>2015-01-28 14:03:12 +0000
commit8da7633f168b5428e2cfb7342408b2c44088f5df (patch)
tree33e17f065d1aa9bf8a57ac03b737154bac0d3468
parentff4b156f166b3931894d2a8b5cdba6cdf4da0618 (diff)
xen: mark grant mapped pages as foreign
Use the "foreign" page flag to mark pages that have a grant map. Use page->private to store information of the grant (the granting domain and the grant reference). 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>
-rw-r--r--arch/x86/xen/p2m.c7
-rw-r--r--drivers/xen/grant-table.c43
-rw-r--r--include/xen/grant_table.h20
3 files changed, 61 insertions, 9 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index a8691cb08420..f18fd1d411f6 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -681,12 +681,8 @@ 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);
-
if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
ret = -ENOMEM;
goto out;
@@ -716,9 +712,6 @@ int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
goto out;
}
- set_page_private(pages[i], INVALID_P2M_ENTRY);
- WARN_ON(!PagePrivate(pages[i]));
- ClearPagePrivate(pages[i]);
set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
if (kunmap_ops)
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index b4f93c490f83..89dcca448bb6 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -679,12 +679,27 @@ EXPORT_SYMBOL_GPL(gnttab_free_auto_xlat_frames);
*/
int gnttab_alloc_pages(int nr_pages, struct page **pages)
{
+ int i;
int ret;
ret = alloc_xenballooned_pages(nr_pages, pages, false);
if (ret < 0)
return ret;
+ for (i = 0; i < nr_pages; i++) {
+#if BITS_PER_LONG < 64
+ struct xen_page_foreign *foreign;
+
+ foreign = kzalloc(sizeof(*foreign), GFP_KERNEL);
+ if (!foreign) {
+ gnttab_free_pages(nr_pages, pages);
+ return -ENOMEM;
+ }
+ set_page_private(pages[i], (unsigned long)foreign);
+#endif
+ SetPagePrivate(pages[i]);
+ }
+
return 0;
}
EXPORT_SYMBOL(gnttab_alloc_pages);
@@ -696,6 +711,16 @@ EXPORT_SYMBOL(gnttab_alloc_pages);
*/
void gnttab_free_pages(int nr_pages, struct page **pages)
{
+ int i;
+
+ for (i = 0; i < nr_pages; i++) {
+ if (PagePrivate(pages[i])) {
+#if BITS_PER_LONG < 64
+ kfree((void *)page_private(pages[i]));
+#endif
+ ClearPagePrivate(pages[i]);
+ }
+ }
free_xenballooned_pages(nr_pages, pages);
}
EXPORT_SYMBOL(gnttab_free_pages);
@@ -756,12 +781,22 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
if (ret)
return ret;
- /* Retry eagain maps */
- for (i = 0; i < count; i++)
+ for (i = 0; i < count; i++) {
+ /* Retry eagain maps */
if (map_ops[i].status == GNTST_eagain)
gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i,
&map_ops[i].status, __func__);
+ if (map_ops[i].status == GNTST_okay) {
+ struct xen_page_foreign *foreign;
+
+ SetPageForeign(pages[i]);
+ foreign = xen_page_foreign(pages[i]);
+ foreign->domid = map_ops[i].dom;
+ foreign->gref = map_ops[i].ref;
+ }
+ }
+
return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count);
}
EXPORT_SYMBOL_GPL(gnttab_map_refs);
@@ -770,12 +805,16 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
struct gnttab_unmap_grant_ref *kunmap_ops,
struct page **pages, unsigned int count)
{
+ unsigned int i;
int ret;
ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count);
if (ret)
return ret;
+ for (i = 0; i < count; i++)
+ ClearPageForeign(pages[i]);
+
return clear_foreign_p2m_mapping(unmap_ops, kunmap_ops, pages, count);
}
EXPORT_SYMBOL_GPL(gnttab_unmap_refs);
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 949803e20872..d3bef563e8da 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -45,6 +45,8 @@
#include <asm/xen/hypervisor.h>
#include <xen/features.h>
+#include <linux/mm_types.h>
+#include <linux/page-flags.h>
#define GNTTAB_RESERVED_XENSTORE 1
@@ -185,4 +187,22 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
+
+struct xen_page_foreign {
+ domid_t domid;
+ grant_ref_t gref;
+};
+
+static inline struct xen_page_foreign *xen_page_foreign(struct page *page)
+{
+ if (!PageForeign(page))
+ return NULL;
+#if BITS_PER_LONG < 64
+ return (struct xen_page_foreign *)page->private;
+#else
+ BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG);
+ return (struct xen_page_foreign *)&page->private;
+#endif
+}
+
#endif /* __ASM_GNTTAB_H__ */