Re: [PATCH] Add an ioctl interface for simple xenstore access

[Anthony Liguori <aliguori@us.ibm.com>]

Muli Ben-Yehuda wrote:
> On Fri, Mar 17, 2006 at 02:33:36PM -0800, Dan Smith wrote:
>
>   
>> This patch adds an ioctl interface to /proc/xen/xenbus to allow simple
>> access to xenstore from domU.  This patch introduces only
>> xenbus_read() support, but write, remove, etc could be easily added.
>> Also, this interface can be easily moved to /dev/xen/xenbus (or
>> something similar) later.
>>     
>
> Hmm, wouldn't a virtual file system be a much better fit for xenstore
> access? the kernel community considers ioctls Evil with a capital E.
>   
I'm not sure how one would express the transaction semantics of xenstore 
via a virtual filesystem.  There is also an awkward mapping between some 
of the attributes of xenstore (for instance, there's no way to determine 
if an attribute returned by a list is a directory or not) that makes a 
filesystem non-trivial.

If you remember, I had written a fuse filesystem front-end for xenstore 
at one point.  It's definitely neat, but I think we would have to make 
some changes to Xenstore for it to really work out well.

Regards,

Anthony Liguori

> Cheers,
> Muli
>