[PATCH] x86: add a bootparameter to reserve high linear address space

[net-next-2.6.git] / arch / i386 / kernel / setup.c

diff --git a/arch/i386/kernel/setup.c b/arch/i386/kernel/setup.c
index 060c68004bec876c4f249292b93ebcc21f1caaf0..16d99444cf66653c446e59534cc9f8e9f704643a 100644 (file)
--- a/arch/i386/kernel/setup.c
+++ b/arch/i386/kernel/setup.c
@@ -934,6 +934,24 @@ static void __init parse_cmdline_early (char ** cmdline_p)
        }
 }
 
+/*
+ * reservetop=size reserves a hole at the top of the kernel address space which
+ * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
+ * so relocating the fixmap can be done before paging initialization.
+ */
+static int __init parse_reservetop(char *arg)
+{
+       unsigned long address;
+
+       if (!arg)
+               return -EINVAL;
+
+       address = memparse(arg, &arg);
+       reserve_top_address(address);
+       return 0;
+}
+early_param("reservetop", parse_reservetop);
+
 /*
  * Callback for efi_memory_walk.
  */