[PATCH 4.9 02/72] xen/setup: Dont relocate p2m over existing one

Greg Kroah-Hartman
2017-04-06T08:41:14Z

From: Ross Lagerwall <ross.lagerwall@citrix.com>

commit 7ecec8503af37de6be4f96b53828d640a968705f upstream.

When relocating the p2m, take special care not to relocate it so
that is overlaps with the current location of the p2m/initrd. This is
needed since the full extent of the current location is not marked as a
reserved region in the e820.

This was seen to happen to a dom0 with a large initial p2m and a small
reserved region in the middle of the initial p2m.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/xen/setup.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -713,10 +713,9 @@ static void __init xen_reserve_xen_mfnli
size = PFN_PHYS(xen_start_info->nr_p2m_frames);
}

- if (!xen_is_e820_reserved(start, size)) {
- memblock_reserve(start, size);
+ memblock_reserve(start, size);
+ if (!xen_is_e820_reserved(start, size))
return;
- }

#ifdef CONFIG_X86_32
/*
@@ -727,6 +726,7 @@ static void __init xen_reserve_xen_mfnli
BUG();
#else
xen_relocate_p2m();
+ memblock_free(start, size);
#endif
}