x86: reserve end-of-conventional-memory to 1MB, 32-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: NAlexander van Heukelum <heukelum@fastmail.fm>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/setup_32.c

@@ -64,6 +64,7 @@
 #include <setup_arch.h>
 #include <bios_ebda.h>
 #include <asm/cacheflush.h>
+#include <asm/processor.h>
 
 /* This value is set up by the early boot code to point to the value
    immediately after the boot time page tables.  It contains a *physical*
@@ -408,12 +409,8 @@ 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);