[libvirt] [PATCH 0/8] logically memory hotplug via guest agent

[Daniel P. Berrange]

On Tue, Jun 09, 2015 at 02:12:39PM +0200, Peter Krempa wrote:
> On Tue, Jun 09, 2015 at 13:05:35 +0100, Daniel Berrange wrote:
> > On Tue, Jun 09, 2015 at 02:03:13PM +0200, Peter Krempa wrote:
> > > On Tue, Jun 09, 2015 at 12:46:27 +0100, Daniel Berrange wrote:
> > > > On Tue, Jun 09, 2015 at 01:22:49PM +0200, Peter Krempa wrote:
> > > > > On Tue, Jun 09, 2015 at 11:05:16 +0100, Daniel Berrange wrote:
> > > > > > On Tue, Jun 09, 2015 at 05:33:24PM +0800, Zhang Bo wrote:
> > > > > 
> 
> ...
> 
> > > > > 2) The guest OS sometimes needs to enable the memory region after ACPI
> > > > > memory hotplug. The GA would be able to online such memory. For this
> > > > > option we don't need to go through a different API though since it can
> > > > > be compounded using a flag.
> > > > 
> > > > So, are you saying that we should not be adding this to the
> > > > virDomainSetMemory API as done in this series, and we should
> > > > instead be able to request automatic enabling/disabling of the
> > > > regions when we do the original DIMM hotplug ?
> > > 
> > > Well, that's the only place where using the memory region GA apis would
> > > make sense for libvirt.
> > > 
> > > Whether we should do it is not that clear. Windows does online the
> > > regions automatically and I was told that some linux distros do it via
> > > udev rules.
> > 
> > What do we do in the case of hotunplug currently ? Are we expectig the
> > guest admin to have manually offlined the regions before doing hotunplug
> > on the host ?
> 
> You don't need to offline them prior to unplug. The guest OS handles
> that automatically when it receives the request.

Hmm, so if the guest can offline and online DIMMS automatically on
hotplug/unplug, then I'm puzzelled what value this patch series
really adds.


Regards,
Daniel
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