Re: [v4][PATCH 11/19] tools: introduce some new parameters to set rdm policy

[Ian Campbell <ian.campbell@citrix.com>]

On Fri, 2015-06-26 at 16:38 +0800, Chen, Tiejun wrote:
> Thanks for your all corrections.
> 
> 
> >> +=item B<type="STRING">
> >> +
> >> +Currently we just have two types:
> >
> > "Currently there are only two types". Although I would probably just say
> > "Valid types are"
> 
> So let say "Currently there are only two valid types".
> 
> >
> >> +"host" means all reserved device memory on this platform should be reserved
> 
> [snip]
> 
> >>   In the future this parameter may be further extended to allow
> >> +specifying random regions, e.g. even those belonging to another platform as
> >> +a preparation for live migration with passthrough devices.
> >
> > Lets document future stuff as it is implemented rather than leaving what
> > is effectively a TODO in the face of the user.
> 
> Okay but I'm not very sure what's that format to introduce a TODO here. 
> Maybe its just like this,
> 
> ...
> regions reported on this platform, which is useful when doing hotplugging.
> 
> TODO: in the future this parameter may be further extended to allow 
> specifying arbitrary regions, e.g. even those belonging to another 
> platform as a preparation for live migration with passthrough devices.

I don't think this needs to be explained in this document at all.
Whenever someone does that work they can update the docs to describe the
new functionality.

> 
> ...
> 
> >
> >> +
> >> +"none" means we have nothing to do all reserved regions and ignore all policies,
> >> +so guest work as before.
> >
> > This doesn't read right, but I'm not sure what you are trying to say so
> > I can't suggest an alternative.
> >
> > How is type=none different from just not specifying rdm at all?
> 
> They're same behavior since "none" is our default option.
> 
> Just let me rephrase this,
> 
> "none" means we don't check any reserved regions and then all rdm 
> policies would be ignored, so guest just work as before.

When or why would I write:
        rdm = "none"
in my configuration file instead of just not saying anything?


> > Having read all these docs I now know what all the options are, but I
> > still don't really know what I should write. I think an example or two
> > of real world usage would be helpful.
> 
> Here I picked some code fragments to help you understand this,

I meant an example or two in the documentation.

The code fragment didn't answer my question either, but that's not
really the point.

> >
> >> +Note this may be overridden by rdm_reserve option in PCI device configuration.
> >> +
> >>   =item B<pci=[ "PCI_SPEC_STRING", "PCI_SPEC_STRING", ... ]>
> >>
> >>   Specifies the host PCI devices to passthrough to this guest. Each B<PCI_SPEC_STRING>
> >> @@ -717,6 +760,13 @@ dom0 without confirmation.  Please use with care.
> >>   D0-D3hot power management states for the PCI device. False (0) by
> >>   default.
> >>
> >> +=item B<rdm_reserv="STRING">
> >> +
> >> +(HVM/x86 only) This is same as reserve option above but just specific
> >> +to a given device, and "strict" is default here.
> >
> > Rather than "above" (which is quite a large block of text) you should
> > specifically mention the rdm option.
> >
> 
> What about this?
> 
> (HVM/x86 only) This is same as reserve option inside the rdm option
> but just specific to a given device, and "strict" is default here.

Is strict the default everywhere or does it differ depending on the
context?