x86: switch to use domheap page for page tables

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Hongyan Xia <hongyxia@amazon.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/mm.c

@@ -4901,10 +4901,10 @@ mfn_t alloc_xen_pagetable_new(void)
 {
     if ( system_state != SYS_STATE_early_boot )
     {
-        void *ptr = alloc_xenheap_page();
+        const struct page_info *pg = alloc_domheap_page(NULL, 0);
 
-        BUG_ON(!hardware_domain && !ptr);
-        return ptr ? virt_to_mfn(ptr) : INVALID_MFN;
+        BUG_ON(!hardware_domain && !pg);
+        return pg ? page_to_mfn(pg) : INVALID_MFN;
     }
 
     return alloc_boot_pages(1, 1);
@@ -4914,7 +4914,7 @@ mfn_t alloc_xen_pagetable_new(void)
 void free_xen_pagetable_new(mfn_t mfn)
 {
     if ( system_state != SYS_STATE_early_boot && !mfn_eq(mfn, INVALID_MFN) )
-        free_xenheap_page(mfn_to_virt(mfn_x(mfn)));
+        free_domheap_page(mfn_to_page(mfn));
 }
 
 void *alloc_mapped_pagetable(mfn_t *pmfn)