K 10
svn:author
V 6
royger
K 8
svn:date
V 27
2015-02-16T09:53:43.725168Z
K 7
svn:log
V 560
xen: fix xenstore dev

Xenstore user-space device has two problems currently:
 - It does not correctly handle concurrent clients, because it's storing
   each client data in dev->si_drv1.
 - It does not correctly free this data when the client closes the device.

In order to solve both of this issues store the per-client data using
cdevpriv, which also comes with a hook in order to perform the necessary
cleanup on device close.

While there also make the device eternal.

Sponsored by: Citrix Systems R&D
Reported and Tested by: thompsa
MFC after: 2 weeks

END