[Xen-devel] [PATCH] x86_64: widen bit width usable for struct domain allocation

["Jan Beulich" <JBeulich@xxxxxxxxxx>]

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@xxxxxxxxxx>

--- 2010-02-09.orig/xen/arch/x86/domain.c       2010-02-09 00:00:00.000000000 
+0100
+++ 2010-02-09/xen/arch/x86/domain.c    2010-02-12 08:44:01.000000000 +0100
@@ -183,11 +183,15 @@ 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;

x86-widen-domain-struct-bits.patch
Description: Text document

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