x86: reserve end-of-conventional-memory to 1MB, 64-bit, use paravirt_enabled

Jeremy Fitzhardinge pointed out that looking at the boot_params
struct to determine if the system is running in a paravirtual
environment is not reliable for the Xen case, currently. He also
points out that there already exists a function to determine if
the system is running in a paravirtual environment. So let's use
that instead. This gets rid of the preprocessor test too.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 269a6b4..48be76c 100644 (file)
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -72,12 +72,8 @@ static void __init reserve_ebda_region(void)
        /* that area is absent. We'll just have to assume */
        /* that the paravirt case can handle memory setup */
        /* correctly, without our help. */
-#ifdef CONFIG_PARAVIRT
-       if ((boot_params.hdr.version >= 0x207) &&
-                       (boot_params.hdr.hardware_subarch != 0)) {
+       if (paravirt_enabled())
                return;
-       }
-#endif
 
        /* end of low (conventional) memory */
        lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);