Re: [PATCH v5] docs/designs: re-work the xenstore migration document...

[Jürgen Groß <jgross@xxxxxxxx>]

On 05.05.20 17:15, Edwin Torok wrote:
> On Tue, 2020-05-05 at 14:13 +0100, Jürgen Groß wrote:
> > On 05.05.20 15:01, Julien Grall wrote:
> > > Hi Paul,
> > >
> > > On 28/04/2020 16:06, Paul Durrant wrote:
> > > > From: Paul Durrant <pdurrant@xxxxxxxxxx>
> > > >
> > > > ... to specify a separate migration stream that will also be
> > > > suitable for
> > > > live update.
> > > >
> > > > The original scope of the document was to support non-
> > > > cooperative
> > > > migration
> > > > of guests [1] but, since then, live update of xenstored has been
> > > > brought into
> > > > scope. Thus it makes more sense to define a separate image format
> > > > for
> > > > serializing xenstore state that is suitable for both purposes.
> > > >
> > > > The document has been limited to specifying a new image format.
> > > > The
> > > > mechanism
> > > > for acquiring the image for live update or migration is not
> > > > covered as
> > > > that
> > > > is more appropriately dealt with by a patch to
> > > > docs/misc/xenstore.txt.
> > > > It is
> > > > also expected that, when the first implementation of live update
> > > > or
> > > > migration
> > > > making use of this specification is committed, that the document
> > > > is
> > > > moved from
> > > > docs/designs into docs/specs.
> > > >
> > > > NOTE: It will only be necessary to save and restore state for
> > > > active
> > > > xenstore
> > > >         connections, but the documentation for 'RESUME' in
> > > > xenstore.txt
> > > > implies
> > > >         otherwise. That command is unused so this patch deletes it
> > > > from
> > > > the
> > > >         specification.
> > Could someone from Citrix please verify that XAPI isn't using
> > XS_RESUME?
> The implementation of XS_RESUME in oxenstored doesn't do much: it seems
> to be just a way for Dom0 to check whether a domain exists or not, and
> for a domain to check whether they are Dom0 or not.
> If the domain exists, then the resume implementation just returns `()`,
> i.e. does nothing.
>
> I can't find any references to Xs.resume in xenopsd (or the other XAPI
> repos that I got checked out), so I think it can be safely removed from
> the spec and client libraries (I'd keep it in the actual oxenstored
> implementation just in case some guest does call it).
Thanks for the confirmation.


Juergen