22 lines
1.1 KiB
YAML
22 lines
1.1 KiB
YAML
---
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features:
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- |
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The Libvirt driver can now add a virtual IOMMU device
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to all created guests, when running on an x86 host and using the Q35
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machine type or on AArch64.
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To enable this, provide `hw:viommu_model` in flavor extra
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spec or equivalent image metadata property `hw_viommu_model` and with the
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guest CPU architecture and OS allows, we will enable viommu in Libvirt
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driver. Support values intel|smmuv3|virtio|auto. Default to ``auto``.
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Which ``auto`` will automatically select ``virtio`` if Libvirt supports it,
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else ``intel`` on X86 (Q35) and ``smmuv3`` on AArch64.
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vIOMMU config will raise invalid exception if the guest architecture is
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neither X86 (Q35) or AArch64.
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Note that, enable vIOMMU might introduce significant performance overhead.
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You can see performance comparision table from
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`AMD vIOMMU session on KVM Forum 2021`_.
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For above reason, vIOMMU should only be enable for workflow that require it.
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.. _`AMD vIOMMU session on KVM Forum 2021`: https://static.sched.com/hosted_files/kvmforum2021/da/vIOMMU%20KVM%20Forum%202021%20-%20v4.pdf
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