Improved "PGDs must be under 4GB" handling for PAE.

Signed-off-by: ian@xensource.com

tools/python/xen/lowlevel/xc/xc.c

@@ -842,6 +842,7 @@ static PyObject *pyxc_domain_memory_increase_reservation(PyObject *self,
     u32 dom;
     unsigned long mem_kb;
     unsigned int extent_order = 0 , address_bits = 0;
+    unsigned long nr_extents;
 
     static char *kwd_list[] = { "dom", "mem_kb", "extent_order", "address_bits", NULL };
 
@@ -849,8 +850,12 @@ static PyObject *pyxc_domain_memory_increase_reservation(PyObject *self,
                                       &dom, &mem_kb, &extent_order, &address_bits) )
         return NULL;
 
+    /* round down to nearest power of 2. Assume callers using extent_order>0
+       know what they are doing */
+    nr_extents = (mem_kb / (XC_PAGE_SIZE/1024)) >> extent_order;
     if ( xc_domain_memory_increase_reservation(xc->xc_handle, dom, 
-                                     mem_kb, extent_order, address_bits) )
+					       nr_extents, extent_order, 
+					       address_bits, NULL) )
         return PyErr_SetFromErrno(xc_error);
     
     Py_INCREF(zero);

tools/python/xen/xend/image.py

@@ -160,8 +160,9 @@ class ImageHandler:
 
         try:
             # Give the domain some memory below 4GB
-            lmem_kb = 4096
-            xc.domain_memory_increase_reservation(dom, min(lmem_kb,mem_kb), 0, 32)
+            lmem_kb = 0
+            if lmem_kb > 0:
+                xc.domain_memory_increase_reservation(dom, min(lmem_kb,mem_kb), 0, 32)
             if mem_kb > lmem_kb:
                 xc.domain_memory_increase_reservation(dom, mem_kb-lmem_kb, 0, 0)
         except: