Re: xl list -l doesn't work for incoming domain

[Wei Liu <wei.liu2@citrix.com>]

On Tue, Nov 11, 2014 at 09:41:32AM -0500, Zhigang Wang wrote:
> On 11/11/2014 06:01 AM, Wei Liu wrote:
> > On Mon, Nov 10, 2014 at 12:54:18PM -0500, Zhigang Wang wrote:
> > [...]
> >> Could you please explain what does "no configuration" means?
> >>
> >> Do you mean no info for the domain at all? If this is the case, it seems not consistent with xl list without -l.
> >>
> > 
> > That means no configuration at all. I think a skeleton can be provided
> > at best (in xl level) to be consistent with "xl list", which should
> > include domid and domain name etc. Since nothing else exists in
> > xenstore yet, there's no point poking there.
> 
> This approach should works for me.
> 
> > [...]
> >> Currently we want our APIs to get domain info by invoking xl list -l, but we can change them to get necessary info from other places.
> >>
> > 
> > Hmm... I don't think poking around in different places is a good idea.
> > This is prone to breakage in the future.
> 
> I agree.
>  
> > Since xenstore is not filled in when your tool looks at it, what makes
> > it different to wait a bit until migration finishes?
> 
> The logic is: when migration started, high level management console will check
> destination side to make sure the VM is running there 
> (currently call xl list -l <domain>).
> 
> If I can get enough runtime info (even some are missing), I think it should be OK.
> 

What runtime info do you need?

As I understand it's something in the long output -- otherwise you would
have used the short output already if you only need to check the
existence and / or state of a domain.

> > And, from your earlier reply, you're implying Xend fires
> > @introduceDomain at the same point as xl, but your tool can work with
> > it?
> 
> For xm/xend, VM xenstore entries already populated before @introduceDomain.
> "xm list -l" will show the right information.
> 
> Anyone knows what prevents us from populating VM xenstore entries during migration in libxl?
> 

FWIW in libxl @introduceDomain is fired after domain is built, before
adding devices. If you're after device information, it's a bit late.

Xend might have done it in different order. I don't know.

Whether we can change libxl to do so, I'm not sure. But it's definitely
not 4.5 material.

Wei.

> Thanks,
> 
> Zhigang