x86_64: widen bit width usable for struct domain allocation

With it being a PDX (instead of a PFN) that gets stored when a 32-bit
quantity is needed, we should also account for the bits removed during
PFN-to-PDX conversion when doing the allocation.

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

1 files changed, 7 insertions, 3 deletions

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 64251eedf8..0ead1a1985 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -174,11 +174,15 @@ struct domain *alloc_domain_struct(void)
 {
     struct domain *d;
     /*
-     * We pack the MFN of the domain structure into a 32-bit field within
+     * We pack the PDX of the domain structure into a 32-bit field within
      * the page_info structure. Hence the MEMF_bits() restriction.
      */
-    d = alloc_xenheap_pages(
-        get_order_from_bytes(sizeof(*d)), MEMF_bits(32 + PAGE_SHIFT));
+    unsigned int bits = 32 + PAGE_SHIFT;
+
+#ifdef __x86_64__
+    bits += pfn_pdx_hole_shift;
+#endif
+    d = alloc_xenheap_pages(get_order_from_bytes(sizeof(*d)), MEMF_bits(bits));
     if ( d != NULL )
         memset(d, 0, sizeof(*d));
     return d;