On Thu, Jun 11, 2015 at 09:38:24 +0800, zhang bo wrote: > On 2015/6/10 17:31, Daniel P. Berrange wrote: > > > 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@xxxxxxxxxx>: > >>>>> 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. > > > > Then, here comes the question: how to deal with the guests that are already in use? > I think it's better to operate them at the host side without getting into the guest. > That's the advantage of qemu-guest-agent, why not take advantage of it? Such guests would need an update qemu-guest-agent anyway. And installing a new version of qemu-guest-agent is not any easier than installing an updated udev or a new udev rule. That is, I don't think the qemu-guest-agent way has any benefits over a udev rule. It's rather the opposite. Jirka -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list