x86-64: reduce range spanned by 1:1 mapping and frame table indexes

Introduces a virtual space conserving transformation on the MFN thus
far used to index 1:1 mapping and frame table, removing the largest
range of contiguous bits (below the most significant one) which are
zero for all valid MFNs from the MFN representation, to be used to
index into those arrays, thereby cutting the virtual range these
tables must cover approximately by half with each bit removed.

Since this should account for hotpluggable memory (in order to not
requiring a re-write when that gets supported), the determination of
which bits are candidates for removal must not be based on the E820
information, but instead has to use the SRAT. That in turn requires a
change to the ordering of steps done during early boot.

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

1 files changed, 23 insertions, 13 deletions

diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index 36f9ccf323..609994ad37 100644
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -103,6 +103,16 @@ struct page_list_head
 
 #define PAGE_LIST_NULL (~0)
 
+# if !defined(pdx_to_page) && !defined(page_to_pdx)
+#  if defined(__page_to_mfn) || defined(__mfn_to_page)
+#   define page_to_pdx __page_to_mfn
+#   define pdx_to_page __mfn_to_page
+#  else
+#   define page_to_pdx page_to_mfn
+#   define pdx_to_page mfn_to_page
+#  endif
+# endif
+
 # define PAGE_LIST_HEAD_INIT(name) { NULL, NULL }
 # define PAGE_LIST_HEAD(name) \
     struct page_list_head name = PAGE_LIST_HEAD_INIT(name)
@@ -123,21 +133,21 @@ static inline struct page_info *
 page_list_next(const struct page_info *page,
                const struct page_list_head *head)
 {
-    return page != head->tail ? mfn_to_page(page->list.next) : NULL;
+    return page != head->tail ? pdx_to_page(page->list.next) : NULL;
 }
 static inline struct page_info *
 page_list_prev(const struct page_info *page,
                const struct page_list_head *head)
 {
-    return page != head->next ? mfn_to_page(page->list.prev) : NULL;
+    return page != head->next ? pdx_to_page(page->list.prev) : NULL;
 }
 static inline void
 page_list_add(struct page_info *page, struct page_list_head *head)
 {
     if ( head->next )
     {
-        page->list.next = page_to_mfn(head->next);
-        head->next->list.prev = page_to_mfn(page);
+        page->list.next = page_to_pdx(head->next);
+        head->next->list.prev = page_to_pdx(page);
     }
     else
     {
@@ -153,8 +163,8 @@ page_list_add_tail(struct page_info *page, struct page_list_head *head)
     page->list.next = PAGE_LIST_NULL;
     if ( head->next )
     {
-        page->list.prev = page_to_mfn(head->tail);
-        head->tail->list.next = page_to_mfn(page);
+        page->list.prev = page_to_pdx(head->tail);
+        head->tail->list.next = page_to_pdx(page);
     }
     else
     {
@@ -191,8 +201,8 @@ __page_list_del_head(struct page_info *page, struct page_list_head *head,
 static inline void
 page_list_del(struct page_info *page, struct page_list_head *head)
 {
-    struct page_info *next = mfn_to_page(page->list.next);
-    struct page_info *prev = mfn_to_page(page->list.prev);
+    struct page_info *next = pdx_to_page(page->list.next);
+    struct page_info *prev = pdx_to_page(page->list.prev);
 
     if ( !__page_list_del_head(page, head, next, prev) )
     {
@@ -204,8 +214,8 @@ static inline void
 page_list_del2(struct page_info *page, struct page_list_head *head1,
                struct page_list_head *head2)
 {
-    struct page_info *next = mfn_to_page(page->list.next);
-    struct page_info *prev = mfn_to_page(page->list.prev);
+    struct page_info *next = pdx_to_page(page->list.next);
+    struct page_info *prev = pdx_to_page(page->list.prev);
 
     if ( !__page_list_del_head(page, head1, next, prev) &&
          !__page_list_del_head(page, head2, next, prev) )
@@ -252,11 +262,11 @@ page_list_splice(struct page_list_head *list, struct page_list_head *head)
     last = list->tail;
     at = head->next;
 
-    first->list.prev = page_to_mfn(head->next);
+    first->list.prev = page_to_pdx(head->next);
     head->next = first;
 
-    last->list.next = page_to_mfn(at);
-    at->list.prev = page_to_mfn(last);
+    last->list.next = page_to_pdx(at);
+    at->list.prev = page_to_pdx(last);
 }
 
 #define page_list_for_each(pos, head) \