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

[Daniel P. Berrange]

On Wed, Jun 10, 2015 at 10:28:08AM +0100, Daniel P. Berrange wrote:
> On Wed, Jun 10, 2015 at 05:24:50PM +0800, zhang bo wrote:
> > On 2015/6/10 16:39, Vasiliy Tolstov wrote:
> > 
> > > 2015-06-10 11:37 GMT+03:00 Daniel P. Berrange <berrange at redhat.com>:
> > >> The udev rules are really something the OS vendor should setup, so
> > >> that it "just works"
> > > 
> > > 
> > > I think so, also for vcpu hotplug this also covered by udev. May be we
> > > need something to hot remove memory and cpu, because in guest we need
> > > offline firstly.
> > > 
> > 
> > 
> > In fact ,we also have --guest option for 'virsh sevvcpus' command, which also
> > uses qga commands to do the logical hotplug/unplug jobs, although udev rules seems
> > to cover the vcpu logical hotplug issue.
> > 
> > virsh # help setvcpus
> > .........................
> >     --guest          modify cpu state in the guest
> > 
> > 
> > BTW: we didn't see OSes with udev rules for memory-hotplug-event setted by vendors, 
> > and adding such rules means that we have to *interfere within the guest*, It seems 
> > not a good option.
> 
> I was suggesting that an RFE be filed with any vendor who doesn't do it
> to add this capability, not that we add udev rules ourselves.

Or actually, it probably is sufficient to just send a patch to the upstream
systemd project to add the desired rule to udev. That way all Linux distros
will inherit the feature when they update to new udev.

Regards,
Daniel
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