nova/releasenotes/notes/libvirt-tb-cache-size-c0d0d672c0950393.yaml
yatinkarel 3f7cc63d94 Add config option to configure TB cache size
Qemu>=5.0.0 bumped the default tb-cache size to 1GiB(from 32MiB)
and this made it difficult to run multiple guest VMs on systems
running with lower memory. With Libvirt>=8.0.0 it's possible to
configure lower tb-cache size.

Below config option is introduced to allow configure
TB cache size as per environment needs, this only
applies to 'virt_type=qemu':-

[libvirt]tb_cache_size

Also enable this flag in nova-next job.

[1] https://github.com/qemu/qemu/commit/600e17b26
[2] https://gitlab.com/libvirt/libvirt/-/commit/58bf03f85

Closes-Bug: #1949606
Implements: blueprint libvirt-tb-cache-size
Change-Id: I49d2276ff3d3cc5d560a1bd96f13408e798b256a
2023-07-13 19:35:52 +05:30

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455 B
YAML

---
features:
- |
Qemu>=5.0.0 bumped the default tb-cache size to 1GiB(from 32MiB) and this
made it difficult to run multiple guest VMs on systems running with lower
memory. With Libvirt>=8.0.0 it's possible to configure lower tb-cache
size. A new config option is introduced:
``[libvirt]tb_cache_size``
This config option can be used to configure tb_cache size
for guest VMs, it's only applicable with ``virt_type=qemu``.