| |
|
 |
|
 |
|
|
|
| |
|
|
xen-devel
Re: [Xen-devel] [PATCH][ACM] kernel enforcement of vbd policies via blkb
On 25 Jul 2006, at 01:21, Reiner Sailer wrote:
Bryan's differentiation makes sense to me. The hooks serve different
purposes:
The xm tools hook is the "usability hook" that ensures users that
domains that get started actually can access their resources.
The block-backend hook is the "enforcement hook" that independently
enforces access control at the time when a resource is mounted.
Right now, both hooks are in the 'large' Domain0. I can imagine that
the xm create resource validation hook eventually moves into a Xen
management GUI that verifies at management time if a domain
configuration is "policy-conform". The block-backend hook could
eventually move together with the block-backend device into a block
device domain for run-time policy enforcement.
The tools hook is not just a usability/conformity check. The check
ensures that the tools will not set up entries in xenstore that would
allow blkback to create a non-conformant vbd. So there is no way for a
guest to trick blkback into creating a non-conformant vbd: it can only
connect to vbds specified in its config file or added later via the
vbd-add xm hotplug command. The tools stack should perform its
compiance checks on both 'xm create' and 'xm vbd-add', and that should
be sufficient.
You have a point about it being nice to check things at the lowest
possible level, but I'm not inclined to add extra crud into the device
drivers for this unless more people scream for it. :-)
-- Keir
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
| |
|
Home