Otherwise a logdirty client can race with observing the page becoming dirty,
and copy the frame before the write is complete and end up with a stale
version.
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
---
CC: Jan Beulich <jbeul...@suse.com>
CC: Julien Grall <julien.gr...@arm.com>
---
xen/arch/x86/mm.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 77b0af1..97c3cb8 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -3556,11 +3556,10 @@ long do_mmuext_op(
break;
}
- /* A page is dirtied when it's being cleared. */
- paging_mark_dirty(pg_owner, _mfn(page_to_mfn(page)));
-
clear_domain_page(_mfn(page_to_mfn(page)));
+ paging_mark_dirty(pg_owner, _mfn(page_to_mfn(page)));
+
put_page_and_type(page);
break;
}
@@ -3594,12 +3593,11 @@ long do_mmuext_op(
break;
}
- /* A page is dirtied when it's being copied to. */
- paging_mark_dirty(pg_owner, _mfn(page_to_mfn(dst_page)));
-
copy_domain_page(_mfn(page_to_mfn(dst_page)),
_mfn(page_to_mfn(src_page)));
+ paging_mark_dirty(pg_owner, _mfn(page_to_mfn(dst_page)));
+
put_page_and_type(dst_page);
put_page(src_page);
break;
--
2.1.4
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
