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author | Zuul <zuul@review.opendev.org> | 2022-09-01 19:56:09 +0000 |
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committer | Gerrit Code Review <review@openstack.org> | 2022-09-01 19:56:09 +0000 |
commit | 457806e2064dbf0d8d2c75f8ed2a9deb0176b6b2 (patch) | |
tree | 43012c120e490bf455b52dafbd5b32fdb6329ca7 /releasenotes | |
parent | 8b55b44cc605533f2a12189a2b5899c0f58c91a7 (diff) | |
parent | 14e3b352c24b2a1fe54ba13a733cf6e7989215cc (diff) | |
download | nova-457806e2064dbf0d8d2c75f8ed2a9deb0176b6b2.tar.gz |
Merge "libvirt: Add vIOMMU device to guest"
Diffstat (limited to 'releasenotes')
-rw-r--r-- | releasenotes/notes/guest-iommu-device-4795c3a060aca424.yaml | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/releasenotes/notes/guest-iommu-device-4795c3a060aca424.yaml b/releasenotes/notes/guest-iommu-device-4795c3a060aca424.yaml new file mode 100644 index 0000000000..314c2c0ffe --- /dev/null +++ b/releasenotes/notes/guest-iommu-device-4795c3a060aca424.yaml @@ -0,0 +1,21 @@ +--- +features: + - | + The Libvirt driver can now add a virtual IOMMU device + to all created guests, when running on an x86 host and using the Q35 + machine type or on AArch64. + + To enable this, provide `hw:viommu_model` in flavor extra + spec or equivalent image metadata property `hw_viommu_model` and with the + guest CPU architecture and OS allows, we will enable viommu in Libvirt + driver. Support values intel|smmuv3|virtio|auto. Default to ``auto``. + Which ``auto`` will automatically select ``virtio`` if Libvirt supports it, + else ``intel`` on X86 (Q35) and ``smmuv3`` on AArch64. + vIOMMU config will raise invalid exception if the guest architecture is + neither X86 (Q35) or AArch64. + + Note that, enable vIOMMU might introduce significant performance overhead. + You can see performance comparision table from + `AMD vIOMMU session on KVM Forum 2021`_. + For above reason, vIOMMU should only be enable for workflow that require it. + .. _`AMD vIOMMU session on KVM Forum 2021`: https://static.sched.com/hosted_files/kvmforum2021/da/vIOMMU%20KVM%20Forum%202021%20-%20v4.pdf |