3 files changed, 46 insertions, 28 deletions

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index c983717c018c..0c8e974c738a 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -37,7 +37,7 @@ extern void xen_syscall_target(void);
 extern void xen_syscall32_target(void);
 
 /* Amount of extra memory space we add to the e820 ranges */
-phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
+struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
 
 /* Number of pages released from the initial allocation. */
 unsigned long xen_released_pages;
@@ -59,7 +59,7 @@ static void __init xen_add_extra_mem(unsigned long pages)
         unsigned long pfn;
 
         u64 size = (u64)pages * PAGE_SIZE;
-        u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
+        u64 extra_start = xen_extra_mem[0].start + xen_extra_mem[0].size;
 
         if (!pages)
                 return;
@@ -69,7 +69,7 @@ static void __init xen_add_extra_mem(unsigned long pages)
 
         memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA");
 
-        xen_extra_mem_size += size;
+        xen_extra_mem[0].size += size;
 
         xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
 
@@ -242,7 +242,7 @@ char * __init xen_memory_setup(void)
 
         memcpy(map_raw, map, sizeof(map));
         e820.nr_map = 0;
-        xen_extra_mem_start = mem_end;
+        xen_extra_mem[0].start = mem_end;
         for (i = 0; i < memmap.nr_entries; i++) {
                 unsigned long long end;
 
@@ -270,8 +270,8 @@ char * __init xen_memory_setup(void)
                                 e820_add_region(end, delta, E820_UNUSABLE);
                 }
 
-                if (map[i].size > 0 && end > xen_extra_mem_start)
-                        xen_extra_mem_start = end;
+                if (map[i].size > 0 && end > xen_extra_mem[0].start)
+                        xen_extra_mem[0].start = end;
 
                 /* Add region if any remains */
                 if (map[i].size > 0)
@@ -279,10 +279,10 @@ char * __init xen_memory_setup(void)
         }
         /* Align the balloon area so that max_low_pfn does not get set
          * to be at the _end_ of the PCI gap at the far end (fee01000).
-         * Note that xen_extra_mem_start gets set in the loop above to be
-         * past the last E820 region. */
-        if (xen_initial_domain() && (xen_extra_mem_start < (1ULL<<32)))
-                xen_extra_mem_start = (1ULL<<32);
+         * Note that the start of balloon area gets set in the loop above
+         * to be past the last E820 region. */
+        if (xen_initial_domain() && (xen_extra_mem[0].start < (1ULL<<32)))
+                xen_extra_mem[0].start = (1ULL<<32);
 
         /*
          * In domU, the ISA region is normal, usable memory, but we
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 9efb993090aa..fc43b53651d7 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -555,11 +555,32 @@ void free_xenballooned_pages(int nr_pages, struct page** pages)
 }
 EXPORT_SYMBOL(free_xenballooned_pages);
 
-static int __init balloon_init(void)
+static void __init balloon_add_region(unsigned long start_pfn,
+                                      unsigned long pages)
 {
         unsigned long pfn, extra_pfn_end;
         struct page *page;
 
+        /*
+         * If the amount of usable memory has been limited (e.g., with
+         * the 'mem' command line parameter), don't add pages beyond
+         * this limit.
+         */
+        extra_pfn_end = min(max_pfn, start_pfn + pages);
+
+        for (pfn = start_pfn; pfn < extra_pfn_end; pfn++) {
+                page = pfn_to_page(pfn);
+                /* totalram_pages and totalhigh_pages do not
+                   include the boot-time balloon extension, so
+                   don't subtract from it. */
+                __balloon_append(page);
+        }
+}
+
+static int __init balloon_init(void)
+{
+        int i;
+
         if (!xen_domain())
                 return -ENODEV;
 
@@ -587,23 +608,12 @@ static int __init balloon_init(void)
 
         /*
          * Initialize the balloon with pages from the extra memory
-         * region (see arch/x86/xen/setup.c).
-         *
-         * If the amount of usable memory has been limited (e.g., with
-         * the 'mem' command line parameter), don't add pages beyond
-         * this limit.
+         * regions (see arch/x86/xen/setup.c).
          */
-        extra_pfn_end = min(max_pfn,
-                            (unsigned long)PFN_DOWN(xen_extra_mem_start
-                                                    + xen_extra_mem_size));
-        for (pfn = PFN_UP(xen_extra_mem_start);
-             pfn < extra_pfn_end;
-             pfn++) {
-                page = pfn_to_page(pfn);
-                /* totalram_pages and totalhigh_pages do not include the boot-time
-                   balloon extension, so don't subtract from it. */
-                __balloon_append(page);
-        }
+        for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++)
+                if (xen_extra_mem[i].size)
+                        balloon_add_region(PFN_UP(xen_extra_mem[i].start),
+                                           PFN_DOWN(xen_extra_mem[i].size));
 
         return 0;
 }
diff --git a/include/xen/page.h b/include/xen/page.h
index 92b61f8c772c..12765b6f9517 100644
--- a/include/xen/page.h
+++ b/include/xen/page.h
@@ -3,7 +3,15 @@
 
 #include <asm/xen/page.h>
 
-extern phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
+struct xen_memory_region {
+        phys_addr_t start;
+        phys_addr_t size;
+};
+
+#define XEN_EXTRA_MEM_MAX_REGIONS 128 /* == E820MAX */
+
+extern __initdata
+struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS];
 
 extern unsigned long xen_released_pages;