xen/p2m: Check for auto-xlat when doing mfn_to_local_pfn.

Most of the functions in page.h are prefaced with
	if (xen_feature(XENFEAT_auto_translated_physmap))
		return mfn;

Except the mfn_to_local_pfn. At a first sight, the function
should work without this patch - as the 'mfn_to_mfn' has
a similar check. But there are no such check in the
'get_phys_to_machine' function - so we would crash in there.

This fixes it by following the convention of having the
check for auto-xlat in these static functions.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index b913915e8e631f9c9ec2996fde3862bd33e2edce..4a092ccdd1471d6ea5246e5801936468808244f8 100644 (file)
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -167,7 +167,12 @@ static inline xpaddr_t machine_to_phys(xmaddr_t machine)
  */
 static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
 {
-       unsigned long pfn = mfn_to_pfn(mfn);
+       unsigned long pfn;
+
+       if (xen_feature(XENFEAT_auto_translated_physmap))
+               return mfn;
+
+       pfn = mfn_to_pfn(mfn);
        if (get_phys_to_machine(pfn) != mfn)
                return -1; /* force !pfn_valid() */
        return pfn;