[[qm_pci_passthrough]]
PCI(e) Passthrough
------------------
+ifdef::wiki[]
+:pve-toplevel:
+endif::wiki[]
PCI(e) passthrough is a mechanism to give a virtual machine control over
a PCI device from the host. This can have some advantages over using
hardware, but even then, many modern system can support this.
Please refer to your hardware vendor to check if they support this feature
-under Linux for your specific setup
+under Linux for your specific setup.
Configuration
.IOMMU
-The IOMMU has to be activated on the kernel commandline. The easiest way is to
-enable trough grub. Edit `'/etc/default/grub'' and add the following to the
-'GRUB_CMDLINE_LINUX_DEFAULT' variable:
+The IOMMU has to be activated on the
+xref:sysboot_edit_kernel_cmdline[kernel commandline].
+
+The command line parameters are:
* for Intel CPUs:
+
amd_iommu=on
----
-[[qm_pci_passthrough_update_grub]]
-To bring this change in effect, make sure you run:
-
-----
-# update-grub
-----
.Kernel Modules
enabled.
----
-# dmesg -e DMAR -e IOMMU -e AMD-Vi
+# dmesg | grep -e DMAR -e IOMMU -e AMD-Vi
----
should display that `IOMMU`, `Directed I/O` or `Interrupt Remapping` is
Please be aware that this option can make your system unstable.
====
-Notes for GPU passthrough
-^^^^^^^^^^^^^^^^^^^^^^^^^
+GPU Passthrough Notes
+^^^^^^^^^^^^^^^^^^^^^
-When passing through a GPU (be it a full device, or a vGPU), if you want to use
-it for displaying, you have to either physically connect a monitor to the
-card (if possible), or configure a remote desktop software (e.g., VNC, RDP)
-inside the guest and use that.
+It is not possible to display the frame buffer of the GPU via NoVNC or SPICE on
+the {pve} web interface.
-It is not possible to display the content of the GPU via NoVNC/SPICE on the
-{pve} web interface.
+When passing through a whole GPU or a vGPU and graphic output is wanted, one
+has to either physically connect a monitor to the card, or configure a remote
+desktop software (for example, VNC or RDP) inside the guest.
-If you want to use the GPU for things like OpenCL or CUDA, this is not an issue,
-since the application should be able to choose the hardware without using
-it as a display.
+If you want to use the GPU as a hardware accelerator, for example, for
+programs using OpenCL or CUDA, this is not required.
Host Device Passthrough
~~~~~~~~~~~~~~~~~~~~~~~
# qm set VMID -hostpci0 00:02.0
----
-If your device has multiple functions (e.g., ``00:02.0`' and ``00:02.1`'),
+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`'
There are some options to which may be necessary, depending on the device
Mediated Devices (vGPU, GVT-g)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Mediated devices are another method to use reuse features and performance from
+Mediated devices are another method to reuse features and performance from
physical hardware for virtualized hardware. These are found most common in
virtualized GPU setups such as Intels GVT-g and Nvidias vGPUs used in their
GRID technology.
^^^^^^^^^^^^^^^^^^
In general your card's driver must support that feature, otherwise it will
-not work. So please refer to your vendor for compatbile drivers and how to
+not work. So please refer to your vendor for compatible drivers and how to
configure them.
-Intels drivers for GVT-g are integraded in the Kernel and should work
-with the 5th, 6th and 7th generation Intel Core Processors, further E3 v4, E3
-v5 and E3 v6 Xeon Processors are supported.
+Intels drivers for GVT-g are integrated in the Kernel and should work
+with 5th, 6th and 7th generation Intel Core Processors, as well as E3 v4, E3
+v5 and E3 v6 Xeon Processors.
-To enable it for Intel Graphcs, you have to make sure to load the module
-'kvmgt' (for example via `/etc/modules`) and to enable it on the Kernel
-commandline. For this you can edit `'/etc/default/grub'' and add the following
-to the 'GRUB_CMDLINE_LINUX_DEFAULT' variable:
+To enable it for Intel Graphics, you have to make sure to load the module
+'kvmgt' (for example via `/etc/modules`) and to enable it on the
+xref:sysboot_edit_kernel_cmdline[Kernel commandline] and add the following parameter:
----
i915.enable_gvt=1
After that remember to
xref:qm_pci_passthrough_update_initramfs[update the `initramfs`],
-xref:qm_pci_passthrough_update_grub[update grub] and
-reboot your host.
+and reboot your host.
VM Configuration
^^^^^^^^^^^^^^^^
With this set, {pve} automatically creates such a device on VM start, and
cleans it up again when the VM stops.
+
+ifdef::wiki[]
+
+See Also
+~~~~~~~~
+
+* link:/wiki/Pci_passthrough[PCI Passthrough Examples]
+
+endif::wiki[]