.IOMMU
-The IOMMU has to be activated on the
+First, the IOMMU support has to be enabled in your BIOS/UEFI. Most often, that
+options is named `IOMMU` or `VT-d`, but check the manual for your motherboard
+for the exact option you need to enable.
+
+Then, the IOMMU has to be activated on the
xref:sysboot_edit_kernel_cmdline[kernel commandline].
The command line parameters are:
----
intel_iommu=on
----
-* for AMD CPUs:
-+
-----
- amd_iommu=on
-----
-
+* for AMD CPUs it should be enabled automatically.
.Kernel Modules
----
If your device has multiple functions (e.g., ``00:02.0`' and ``00:02.1`' ),
-you can pass them through all together with the shortened syntax ``00:02`'
+you can pass them through all together with the shortened syntax ``00:02`'.
+This is equivalent with checking the ``All Functions`' checkbox in the
+web-interface.
There are some options to which may be necessary, depending on the device
and guest OS:
# qm set VMID -hostpci0 02:00,pcie=on,x-vga=on
----
+.PCI ID overrides
+
+You can override the PCI vendor ID, device ID, and subsystem IDs that will be
+seen by the guest. This is useful if your device is a variant with an ID that
+your guest's drivers don't recognize, but you want to force those drivers to be
+loaded anyway (e.g. if you know your device shares the same chipset as a
+supported variant).
+
+The available options are `vendor-id`, `device-id`, `sub-vendor-id`, and
+`sub-device-id`. You can set any or all of these to override your device's
+default IDs.
+
+For example:
+
+----
+# qm set VMID -hostpci0 02:00,device-id=0x10f6,sub-vendor-id=0x0000
+----
+
Other considerations
^^^^^^^^^^^^^^^^^^^^