Re: [libvirt] RFC: New CPU hot(un)plug API and XML

On Wed, Jun 15, 2016 at 18:10:01 +0100, Daniel Berrange wrote: > On Mon, Jun 13, 2016 at 02:48:51PM +0200, Peter Krempa wrote: TL;DR: I mostly agree with your suggestions altough there's a slight problem with the suggested XML format. See [1] at the bottom > > <domain> > > [...] > > <vcpu current='1'>3</vcpu> > > <vcpus> > > <vcpu id='0' state='enabled'/> <-- option 1, no extra data > > <vcpu id='1' state='disabled' cell='1'/> <--- option 2, just numa node, > > since it's non-obvious > > <vcpu id='2' state='disabled' cell='1' pin='1-2' scheduler='...'/> > > <!-- option 3 all the data duplicated --> > > </vcpus> > > [...] > > <cputune> > > <cpupin ... /> > > </cputune> > > [...] > > <cpu> > > <numa> > > <cell id='0' cpus='0' memory='102400' unit='KiB/> > > <cell id='1' cpus='1-2' memory='102400' unit='KiB/> > > </numa> > > In the 'virsh capabilities' XML, the CPUs are listed underneath the > <cell>. So rather than adding <vcpu> as children of <vcpus>, I think > perhaps we should just put then under the <cell> here too. That would > avoid the need to add a cell=NN attribute.eg > > <cpu> > <numa> > <cell id='0' cpus='0' memory='102400' unit='KiB> > <cpus> > <cpu id="0" state="enabled"/> > </cpus> > </cell> > <cell id='1' cpus='1-2' memory='102400' unit='KiB> > <cpus> > <cpu id="1" state="disabled"/> > <cpu id="2" state="enabled"/> > </cpus> > </cell> > </numa> [1] I was thinking doing the same at first but there's one caveat. For non-numa guests you don't get the <numa> element at all. In such case the online/offline state would need to be kept somewhere else and I wanted to avoid having two places where to put the data. I've opted for adding a new element which would satisfy even non-numa guests at the expense that you'd need to collate from two places in case of numa guests.