Commit 18c51e1a authored Nov 11, 2013 by Stefano Stabellini Committed by Konrad Rzeszutek Wilk Nov 11, 2013

xen/arm: pfn_to_mfn and mfn_to_pfn return the argument if nothing is in the p2m



Some common Xen drivers, like balloon.c, call pfn_to_mfn and mfn_to_pfn
even for autotranslate guests, expecting the argument back.
The following commit broke these drivers by changing the behavior of
pfn_to_mfn and mfn_to_pfn:

commit 4a19138c
Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Date:   Thu Oct 17 16:22:27 2013 +0000

    arm/xen,arm64/xen: introduce p2m

They now return INVALID_P2M_ENTRY if Linux doesn't actually know what is
the mfn backing a pfn or what is the pfn corresponding to an mfn.
Fix the regression by switching to the old behavior.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Tested-by: Ian Campbell <ian.campbell@citrix.com>

parent ffc555be

arch/arm/include/asm/xen/page.h

+2 −8

Original line number	Diff line number	Diff line
		@@ -46,10 +46,7 @@ static inline unsigned long pfn_to_mfn(unsigned long pfn)
		return mfn;
		}

		if (xen_initial_domain())
		return pfn;
		else
		return INVALID_P2M_ENTRY;
		}

		static inline unsigned long mfn_to_pfn(unsigned long mfn)
		@@ -62,10 +59,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
		return pfn;
		}

		if (xen_initial_domain())
		return mfn;
		else
		return INVALID_P2M_ENTRY;
		}

		#define mfn_to_local_pfn(mfn) mfn_to_pfn(mfn)