[pve-devel] applied: [PATCH docs 2/2] add documentation for mediated devices

[Thomas Lamprecht]

On 11/13/18 3:18 PM, Dominik Csapak wrote:
> Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
> ---
>  qm-pci-passthrough.adoc | 68 +++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
> 
> diff --git a/qm-pci-passthrough.adoc b/qm-pci-passthrough.adoc
> index 6a70469..517d979 100644
> --- a/qm-pci-passthrough.adoc
> +++ b/qm-pci-passthrough.adoc
> @@ -275,3 +275,71 @@ For this feature, platform support is especially important. It may be necessary
>  to enable this feature in the BIOS/EFI first, or to use a specific PCI(e) port
>  for it to work. In doubt, consult the manual of the platform or contact its
>  vendor.
> +
> +Mediated Devices, vGPU/GVT-g
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +Mediated devices are another method to use virtualized hardware.
> +These are found most common in virtualized GPU setups such as
> +Intels GVT-g and Nvidias vGPUs used in their GRID technology.
> +
> +With this, a physical Card is able to create virtual cards, similar to
> +SR-IOV, the difference is that mediated devices do not appear as PCI(e) devices
> +in the host, and are such only suited for using in virtual machines.
> +
> +Host Configuration
> +^^^^^^^^^^^^^^^^^^
> +
> +In general your driver of the card must support that feature, otherwise it will
> +not work. So please refer to your vendor for compatbile drivers and how to
> +configure them.
> +
> +Intels drivers for GVT-g are integraded in the Kernel and should work
> +with 5th, 6th and 7th generation Intel Core Processors and 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:
> +
> +----
> + 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.
> +
> +VM Configuration
> +^^^^^^^^^^^^^^^^
> +
> +To use a mediated device, simply specify the `mdev` on a `hostpciX`
> +configuration of a VM. This needs to be a type of mediated device supported
> +by the specified PCI(e) card.
> +
> +You can get the supported devices via the 'sysfs'. For example, listing
> +the supported types for the device '0000:00:02.0' you can simply list them
> +with:
> +
> +----
> +# ls /sys/bus/pci/devices/0000:00:02.0/mdev_supported_types
> +----
> +
> +Each entry is a directory which contains the following important files:
> +
> +* 'available_instances' contains the amount of still available instances of this
> +type
> +* 'description' contains a short description about the capabilities of the type
> +* 'create' is the endpoint to create such a device, in {pve} this happens
> +automatically if you specify a type with a 'hostpciX' line.
> +
> +Example configuration of a Intel GVT-g vGPU on an Intel Skylake 6700k Processor:
> +
> +----
> +# qm set VMID -hostpci0 00:02.0,mdev=i915-GVTg_V5_4
> +----
> +
> +With this set, {pve} automatically creates such a device on VM start, and
> +cleans it up again when the VM stops.
> 

applied, awaiting qemu-server v2, to make the docs tell the truth ;-)