Re: [PATCH RFC v3 09/16] qemu: hotplug: Support hot attach and detach block disk along with throttle filters

On 2024/8/16 23:14, Peter Krempa wrote: > On Thu, Aug 15, 2024 at 13:04:47 +0800, Chun Feng Wu wrote: > > (I'd suggest you trim irrelevant stuff when responding. It's hard to > find what you've responded to in this massive message . > > > On 2024/8/9 22:04, Peter Krempa wrote: > > > On Wed, Jun 12, 2024 at 03:02:17 -0700,wucf(a)linux.ibm.com wrote: > > > > From: Chun Feng Wu<wucf(a)linux.ibm.com>

> > it apply groups on top source(vm1_disk_2.qcow2) only? is there scenario to > > apply throttle-groups on backing store source? > > > >   <disk type='file' device='disk'> > >       <driver name='qemu' type='qcow2'/> > >       <source file='/virt/disks/vm1_disk_2.qcow2' index='1'> > >           <throttlefilters> > >             <throttlefilter group='limit0'/> > >           </throttlefilters> > >       </source> > >       <backingStore type='file' index='4'> > >         <format type='qcow2'/> > >         <source file='/virt/disks/backing.qcow2'> > >           <throttlefilters> > >             <throttlefilter group='limit1'/> > >           </throttlefilters> > >         </source> > >         <backingStore/> > >       </backingStore> > >       <target dev='vdc' bus='virtio'/> > >       <alias name='virtio-disk2'/> > >       <address type='pci' domain='0x0000' bus='0x00' slot='0x06' > > function='0x0'/> > >    </disk> > > Yeah, something like this. That allows adding filters on other layers > too. > > As I said it depends on how you expect to use this feature, because both > make sense. > > I do reckon that in most cases this is an overkill though. > > If you decide that this is too complicated, you can use the approach you > did, but then need to store the nodename of the throttle layer on the > disk level in the status XML. sure, then let's stick to current implementation about filter chain(per-disk), about status XML, do you mean <privateData> to store nodename? if so, does the following xml look good to you?   <throttlefilters>     <throttlefilter  group='limit2'>       <privateData>         <nodename type='throttle-filter' name='0123456789ABCDEF0123456789ABCDE'/>       </privateData>     </throttlefilter>   </throttlefilters>