tree c336f20e2618949cd250aae388060baaef4182df
parent 669b0ae961e87c824233475e987b2d39996d4849
author Andres Lagar-Cavilla <andres@lagarcavilla.org> 1377277806 +0100
committer Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 1377866693 -0400

Xen: Fix retry calls into PRIVCMD_MMAPBATCH*.

When a foreign mapper attempts to map guest frames that are paged out,
the mapper receives an ENOENT response and will have to try again
while a helper process pages the target frame back in.

Gating checks on PRIVCMD_MMAPBATCH* ioctl args were preventing retries
of mapping calls.

Permit subsequent calls to update a sub-range of the VMA, iff nothing
is yet mapped in that range.

Since it is now valid to call PRIVCMD_MMAPBATCH* multiple times, only
set vma->vm_private_data if the parameters are valid and (if
necessary) the pages for the auto_translated_physmap case have been
allocated.  This prevents subsequent calls from incorrectly entering
the 'retry' path when there are no pages allocated etc.

Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>