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| author | Stephen Finucane <stephenfin@redhat.com> | 2022-02-23 16:14:03 +0000 |
|---|---|---|
| committer | ricolin <rlin@vexxhost.com> | 2022-09-01 04:50:16 +0800 |
| commit | 14e3b352c24b2a1fe54ba13a733cf6e7989215cc (patch) | |
| tree | 5dcc7b9dd9f9249b1f4d77d6c603834d851a8c8c /releasenotes/notes | |
| parent | 733a87e6126e4da8261eada74ba2cd0ec55f8a72 (diff) | |
| download | nova-14e3b352c24b2a1fe54ba13a733cf6e7989215cc.tar.gz | |
libvirt: Add vIOMMU device to guest
Implementation for BP/libvirt-viommu-device.
With provide `hw:viommu_model` property to extra_specs or
`hw_viommu_model` to image property. will enable viommu to libvirt
guest.
[1] https://www.berrange.com/posts/2017/02/16/setting-up-a-nested-kvm-guest-for-developing-testing-pci-device-assignment-with-numa/
[2] https://review.opendev.org/c/openstack/nova-specs/+/840310
Implements: blueprint libvirt-viommu-device
Change-Id: Ief9c550292788160433a28a7a1c36ba38a6bc849
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>
Diffstat (limited to 'releasenotes/notes')
| -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 |