Introduce new flavour of map_domain_page()

Introduce a variant of map_domain_page() directly getting passed a
struct page_info * argument, based on the observation that in many
places the argument to this function so far simply was the result of
page_to_mfn(). This is meaningful for the x86-64 case where
map_domain_page() really just is an invocation of mfn_to_virt(), and
hence the combined mfn_to_virt(page_to_mfn()) now represents a
needless round trip conversion compressed -> uncompressed ->
compressed of the MFN representation.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/xen/arch/x86/tboot.c b/xen/arch/x86/tboot.c
index 49254273ec..e40605d118 100644
--- a/xen/arch/x86/tboot.c
+++ b/xen/arch/x86/tboot.c
@@ -205,8 +205,7 @@ static void tboot_gen_domain_integrity(const uint8_t key[TB_KEY_SIZE],
 
         page_list_for_each(page, &d->page_list)
         {
-            void *pg;
-            pg = map_domain_page(page_to_mfn(page));
+            void *pg = __map_domain_page(page);
             vmac_update(pg, PAGE_SIZE, &ctx);
             unmap_domain_page(pg);
         }