Re: [libvirt] [RFC PATCH auto partition NUMA guest domains v1 0/2] auto partition guests providing the host NUMA topology

On Tue, Sep 25, 2018 at 12:02:40 +0200, Wim Ten Have wrote: I'm pretty sure someone would find this useful and such configuration is perfectly valid in libvirt. But I don't think there is a compelling reason to add some magic into the domain XML which would automatically expand to such configuration. It's basically a NUMA placement policy and libvirt generally tries to avoid including any kind of policies and rather just provide all the mechanisms and knobs which can be used by applications to implement any policy they like. Anyway, this is definitely not the right place for such option. The 'check' attribute is described as "Since 3.2.0, an optional check attribute can be used to request a specific way of checking whether the virtual CPU matches the specification." and the new 'numa' value does not fit in there in any way. Moreover the code does the automatic NUMA placement at the moment libvirt parses the domain XML, which is not the right place since it would break migration, snapshots, and save/restore features. We have existing placement attributes for vcpu and numatune/memory elements which would have been much better place for implementing such feature. And event cpu/numa element could have been enhanced to support similar configuration. Jirka