Signed-off-by: Markus Frank <[email protected]> --- qm-pci-passthrough.adoc | 31 +++++++++++++++++++++++++++++++ qm.adoc | 1 + 2 files changed, 32 insertions(+)
diff --git a/qm-pci-passthrough.adoc b/qm-pci-passthrough.adoc index b90a0b9..9737165 100644 --- a/qm-pci-passthrough.adoc +++ b/qm-pci-passthrough.adoc @@ -408,6 +408,37 @@ properly used with HA and hardware changes are detected and non root users can configure them. See xref:resource_mapping[Resource Mapping] for details on that. +[[qm_pci_viommu]] +vIOMMU +~~~~~~ + +Using the vIOMMU option allows you to to passthrough PCI devices to level-2 +VMs in level-1 VMs via nested virtualisation. + +Host requirement: + +* Add `intel_iommu=on` or `amd_iommu=on` depending on your CPU to your kernel +command line. + +VM requirements: + +* Whether you are using an Intel or AMD CPU on your host, it is important to set +`intel_iommu=on` in the VMs kernel parameters. +This is necessary because the Intel variant in QEMU is better documentated +and has more features. + +* To use vIOMMU you need to set *q35* as the machine type and *kvm* needs +to be enabled. + +If all requirements are met, you can add `viommu=1` to the machine parameter +in the configuration of the VM that should be able to passthrough PCI devices. + +---- +# qm set VMID -machine q35,viommu=1 +---- + +https://wiki.qemu.org/Features/VT-d + ifdef::wiki[] See Also diff --git a/qm.adoc b/qm.adoc index b3c3034..33f02f2 100644 --- a/qm.adoc +++ b/qm.adoc @@ -145,6 +145,7 @@ default https://en.wikipedia.org/wiki/Intel_440FX[Intel 440FX] or the https://ark.intel.com/content/www/us/en/ark/products/31918/intel-82q35-graphics-and-memory-controller.html[Q35] chipset, which also provides a virtual PCIe bus, and thus may be desired if one wants to pass through PCIe hardware. +Additionally you can use xref:qm_pci_viommu[vIOMMU] with Q35. [[qm_hard_disk]] Hard Disk -- 2.39.2 _______________________________________________ pve-devel mailing list [email protected] https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
