xen: don't add extra_pages for RAM after mem_end
If an E820 region is entirely beyond mem_end, don't attempt to truncate
it and add the truncated pages to extra_pages, as they will be negative.
Also, make sure the extra memory region starts after all BIOS provided
E820 regions (and in the case of RAM regions, post-clipping).
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index cad2fcd..7a4ab05 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -52,20 +52,19 @@
static __init void xen_add_extra_mem(unsigned long pages)
{
u64 size = (u64)pages * PAGE_SIZE;
+ u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
if (!pages)
return;
- e820_add_region(xen_extra_mem_start + xen_extra_mem_size, size, E820_RAM);
+ e820_add_region(extra_start, size, E820_RAM);
sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
- reserve_early(xen_extra_mem_start + xen_extra_mem_size,
- xen_extra_mem_start + xen_extra_mem_size + size,
- "XEN EXTRA");
+ reserve_early(extra_start, extra_start + size, "XEN EXTRA");
xen_extra_mem_size += size;
- xen_max_p2m_pfn = PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size);
+ xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
}
static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
@@ -175,15 +174,21 @@
unsigned long long end = map[i].addr + map[i].size;
if (map[i].type == E820_RAM) {
- if (end > mem_end) {
+ if (map[i].addr < mem_end && end > mem_end) {
/* Truncate region to max_mem. */
- map[i].size -= end - mem_end;
+ u64 delta = end - mem_end;
- extra_pages += PFN_DOWN(end - mem_end);
+ map[i].size -= delta;
+ extra_pages += PFN_DOWN(delta);
+
+ end = mem_end;
}
- } else if (map[i].type != E820_RAM)
+ }
+
+ if (end > xen_extra_mem_start)
xen_extra_mem_start = end;
+ /* If region is non-RAM or below mem_end, add what remains */
if ((map[i].type != E820_RAM || map[i].addr < mem_end) &&
map[i].size > 0)
e820_add_region(map[i].addr, map[i].size, map[i].type);