Re: [PATCH] tools: set migration constraints from cmdline

[Olaf Hering <olaf@aepfle.de>]

On Mon, Feb 04, Ian Campbell wrote:

> On Mon, 2013-02-04 at 09:57 +0000, Olaf Hering wrote:
> > On Wed, Jan 30, Ian Campbell wrote:
> > 
> > > On Mon, 2013-01-28 at 17:32 +0000, Olaf Hering wrote:
> > > > A variant of this change has been tested with xend, the patch below is
> > > > only compile tested. The changes to libxl change the API, is that
> > > > approach acceptable?
> > > 
> > > I'm afraid not, the compatibility requirements are covered in the
> > > comment near the top of libxl.h.
> > > 
> > > So you either need a new function or to leverage the LIBXL_API_VERSION
> > > define (which the user must supply) such that people providing 0x040200
> > > see the current interface and people providing 0x040300 (or nothing) see
> > > the new one.
> > 
> > And to avoid the API change at all, should max_iters and max_factor be
> > passed via xenstore to xc_domain_save()? So that either the caller of
> > xc_domain_save reads the values from xenstore, or the function itself
> > reads it from there. What do you think?
> 
> Unfortunately libxc cannot access xenstore.

In case of xm, it would be the xc_save binary, which can receive both
values from argv[].
In case of xl, it would be a xenstore write in main_migrate and a read
in libxl_domain_suspend. Which would cover also other callers of
libxl_domain_suspend.

Olaf