x86/setup: remove bootstrap_map_addr() usage of destroy_xen_mappings()

bootstrap_map_addr() needs to be careful to not remove existing page-table
structures when tearing down mappings, as such pagetable structures might be
needed to fulfill subsequent mappings requests.  The comment ahead of the
function already notes that pagetable memory shouldn't be allocated.

Fix this by using map_pages_to_xen(), which does zap the page-table entries,
but does not free page-table structures even when empty.

Fixes: 4376c05c31 ('x86-64: use 1GB pages in 1:1 mapping if available')
Signed-off-by: Roger Pau Monné <roger.pau@ctrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 73194b5701
master date: 2024-11-14 16:12:51 +0100

xen/arch/x86/setup.c

@@ -402,7 +402,9 @@ void *__init bootstrap_map(const module_t *mod)
 
     if ( !mod )
     {
-        destroy_xen_mappings(BOOTSTRAP_MAP_BASE, BOOTSTRAP_MAP_LIMIT);
+        map_pages_to_xen(BOOTSTRAP_MAP_BASE, INVALID_MFN,
+                         PFN_DOWN(map_cur - BOOTSTRAP_MAP_BASE),
+                         _PAGE_NONE);
         map_cur = BOOTSTRAP_MAP_BASE;
         return NULL;
     }