Re: xenstore domain

[Juergen Gross <jgross@suse.com>]

On 08/12/15 16:04, Andrew Cooper wrote:
> On 08/12/15 14:44, Juergen Gross wrote:
>> I'm just playing a little bit with xenstore in an own domain.
>>
>> I've come across some questions I'd like to have some answers to before
>> presenting official patches to make this an easy configurable option:
>>
>> a) As this would need a boot time configuration item I'd like to add
>>    e.g. /etc/xen/server.conf where such global configuration options
>>    could be set via directives. Is this generally okay? If yes, which
>>    format? Easiest way would be entries like
>>    VAR=value
>>    which can be either sourced in from shell scripts or can easily be
>>    parsed in all programming languages. What are the preferences here?
> 
> Any configuration like this going to be toolstack-specific.  I would
> recommend against using a name as generic as that.
> 
> /etc/xl.conf already exists, which IMO would be the natural place for
> this to live, but it isn't parseable by shell, because of vif notation.

OTOH that file wouldn't be just for xl. It would be consumed by e.g.
xencommons. Other configuration options I'd plan to add would be
driver domains dedicated to specific interface cards.

> One option might be to alter xl.conf to be compatible with shell
> parsing.  It wouldn't be complicated (even in upgrade situations), and
> would offer rather more flexibility.

Shell parsing could be even handled via a rather simple filter, I guess.

>> b) Today init-xenstore-domain will require flask to be enabled. An
>>    alternative would be to add a new domain creation flag to allow the
>>    domains with that flag set calling xc_domain_getinfo(). Thoughts?
> 
> Which flag?

A new domcr_flag.

>> c) In order to be as flexible as possible I think the xenstore domain
>>    should be allowed to auto-balloon according to it's needs. Is anyone
>>    already working on ballooning support for mini-os?
> 
> This is the C xenstore?  Have you investigated whether Mirage-based
> stubdomains can balloon?

Aren't they based on mini-os, too?


Juergen