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+++ This bug was initially created as a clone of Bug #1382425 +++ Description of problem: Current -numa CLI interface is quite limited in terms that allow map CPUs to NUMA nodes as it requires to provide cpu_index values which are non obvious and depend on machine/arch. As result libvirt has to assume/re-implement cpu_index allocation logic to provide valid values for -numa cpus=... QEMU CLI option. Now QEMU has in place generic CPU hotplug interface and ability to query possible CPUs layout (with QMP command query-hotpluggable-cpus), however it requires to run QEMU once per each machine type and topology configuration (-M & -smp combination) which would be too taxing for mgmt layer to do. Currently proposed idea to solve the issue is to do NUMA mapping at runtime: 1. start QEMU in stopped mode with needed -M & -smp configuration but leave out "-numa cpus" options 2. query possible cpus layout (query-hotpluggable-cpus) 3. use new QMP command to map CPUs to NUMA node in terms of generic CPU hotplug interface (socket/core/thread) 3.1 potentially translate mapping as new CLI options so the same configuration could be started without runtime configuration step 4. continue VM exection
CLI part of interface is merged in qemu-2.10, it added new CLI option -numa cpu=[socket-id/core-id/thread-id] see commit 419fcdec3 "numa: add '-numa cpu,...' option for property based node mapping" for more details.
We probably should keep it open (CCing Michal) PS: One way to raise interest in implementing it, could be deprecating legacy -numa node,cpu='' on QEMU side, to 'help' users adopt 'new' interface.
Yeah, for that we firstly need to address bug 1678085 and then we can look into this.
Moving to advanced virt where this will be addressed first. Also resetting the stale date as this is still desired to be supported.
After evaluating this issue, there are no plans to address it further or fix it in an upcoming release. Therefore, it is being closed. If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened.
Bulk update: Move RHEL-AV bugs to RHEL9. If necessary to resolve in RHEL8, then clone to the current RHEL8 release.
*** This bug has been marked as a duplicate of bug 1678085 ***