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IGVT-g: Difference between revisions

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Add note about GVT-g removal and SR-IOV future
 
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Intel GVT-g is a full GPU virtualization solution with mediated pass-through which allows host and multiple guests to share same Intel integrated videocard. Guest gets a near-native graphics peformance.
Intel GVT-g is a technology that allows to "slice" an Intel GPU into virtualized GPUs that can be then passed into virtual machines.


Win7-32 / Win7-64 / Win8.1-64 /Win10-RS1-64 are validated.
Note that Intel GVT-g only supports Intel Broadwell (5th gen) to Comet Lake (10th gen), where in 10th gen support for IVGT-g was removed. For 11th gen, and 12th gen, there is SR-IOV coming up for virtualized GPUs, but that did not yet arrive in Linux mainline.


== Hardware Requirements ==
== Configuring GPU ==


For client platforms, 5th, 6th or 7th Generation Intel® Core Processor Graphics is required. For server platforms, E3_v4, E3_v5 or E3_v6 Xeon Processor Graphics is required.
First, enable iGVT-g with:
 
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
virtualisation.kvmgt.enable = true;
</nowiki>}}
... then rebuild and reboot.
 
 
After rebooting, check if the driver was successfully loaded:
 
  $ ls /sys/bus/pci/devices/0000:00:02.0/mdev_supported_types/
 
... if you get <code>No such file or directory</code>, it means you might be using an older CPU that needs an extra configuration option:
 
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
boot.extraModprobeConfig = "options i915 enable_guc=2";
</nowiki>}}
... then rebuild and reboot once again (unless that previous <code>ls</code> succeeded, in which case you don't have to modify that <code>extraModprobeConfig</code> at all).


== Create or destroy VGPU ==


Choose virtual GPU
Now, using <code>ls</code> you can list which variants your Intel GPU is able to virtualise:


<pre>
  $ ls /sys/bus/pci/devices/0000:00:02.0/mdev_supported_types/
$ ls /sys/bus/pci/devices/0000:00:02.0/mdev_supported_types/
  i915-GVTg_V5_4/  i915-GVTg_V5_8/
i915-GVTg_V5_4/  i915-GVTg_V5_8/
</pre>


<pre>
E.g.:
$ cat /sys/bus/pci/devices/0000:00:02.0/mdev_supported_types/i915-GVTg_V5_8/description
low_gm_size: 64MB
high_gm_size: 384MB
fence: 4
resolution: 1024x768
weight: 2
</pre>


Generate UUID
  $ cat /sys/bus/pci/devices/0000:00:02.0/mdev_supported_types/i915-GVTg_V5_8/description
  low_gm_size: 64MB
  high_gm_size: 384MB
  fence: 4
  resolution: 1024x768
  weight: 2


<pre>
Find some variant that matches your expectations (resolution, memory size etc.), note down its name, generate a random UUID:
$ nix run nixpkgs.libossp_uuid -c uuid
 
a297db4a-f4c2-11e6-90f6-d3b88d6c9525
  # If you're using Nix Flakes:
</pre>
  $ nix shell nixpkgs#libossp_uuid -c uuid
  a297db4a-f4c2-11e6-90f6-d3b88d6c9525
 
  # If you're not using Nix Flakes:
  $ nix run nixpkgs.libossp_uuid -c uuid
  a297db4a-f4c2-11e6-90f6-d3b88d6c9525
 
... and add that variant's name into your configuration:


== NixOS configuration ==
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
  boot.kernelPackages = pkgs.linuxPackages_4_16;
virtualisation.kvmgt.enable = true;  
  virtualisation.kvmgt.enable = true;  
virtualisation.kvmgt.vgpus = {
  virtualisation.kvmgt.vgpus = {
  "i915-GVTg_V5_8" = {
    "i915-GVTg_V5_8" = {
    uuid = [ "a297db4a-f4c2-11e6-90f6-d3b88d6c9525" ];
      uuid = "a297db4a-f4c2-11e6-90f6-d3b88d6c9525";
    };
   };
   };
  environment.systemPackages = with pkgs; [
};
 
environment.systemPackages = with pkgs; [
   virtmanager
   virtmanager
  virt-viewer
];
  ];
 
  virtualisation.libvirtd.enable = true;
virtualisation.libvirtd.enable = true;
  users.extraUsers.user.extraGroups = [ "libvirtd" ];
users.extraUsers.user.extraGroups = [ "libvirtd" ];
</nowiki>}}
</nowiki>}}


== Configure KVM ==
Rebuild & voilá - your virtualized GPU is ready; now you just have to attach it to some virtual machine.


Support for local display is present in Qemu 2.12.
== Attaching GPU ==


=== Bare Qemu ===
=== Bare Qemu ===
<syntaxHighlight lang="sh">
 
   qemu-system-x86_64 \
   qemu-system-x86_64 \
     -enable-kvm \
     -enable-kvm \
     -m 1G \
     -m 1G \
     -nodefaults \
     -nodefaults \
    -M graphics=off \
    -serial stdio \
     -display gtk,gl=on \
     -display gtk,gl=on \
     -device vfio-pci,sysfsdev=/sys/bus/mdev/devices/a297db4a-f4c2-11e6-90f6-d3b88d6c9525,x-igd-opregion=on
     -device vfio-pci,sysfsdev=/sys/bus/mdev/devices/'''a297db4a-f4c2-11e6-90f6-d3b88d6c9525''',display=on,x-igd-opregion=on,driver=vfio-pci-nohotplug,ramfb=on,xres=1920,yres=1080
</syntaxHighlight>
 
=== libvirt ===


=== libvirtd ===
If using virt-manager, create new or open existing VM. Change existing <code><graphics></code> and <code><video></code> sections.
If using virt-manager, create new or open existing VM.


sudo -E virsh edit win10
sudo -E virsh edit win10
<pre>
<syntaxHighlight lang="xml" highlight="1,12">
<domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
<domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
<devices>
  <devices>
<graphics type='spice'>
    <graphics type='spice'>
  <listen type='none'/>
      <listen type='none'/>
  <gl enable='yes'/>
      <gl enable='yes'/>
</graphics>
    </graphics>
<hostdev mode='subsystem' type='mdev' managed='no' model='vfio-pci'>
    <video>
  <source>
      <model type='none'/>
    <address uuid='a297db4a-f4c2-11e6-90f6-d3b88d6c9525'/>
    </video>
  </source>
    <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-pci' display='on'>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>
      <source>
</hostdev>
        <address uuid='a297db4a-f4c2-11e6-90f6-d3b88d6c9525'/>
</devices>
      </source>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>
    </hostdev>
  </devices>
   <qemu:commandline>
   <qemu:commandline>
  <qemu:arg value='-set'/>
    <qemu:arg value='-set'/>
  <qemu:arg value='device.hostdev0.x-igd-opregion=on'/>
    <qemu:arg value='device.hostdev0.x-igd-opregion=on'/>
    <qemu:arg value='-set'/>
    <qemu:arg value='device.hostdev0.ramfb=on'/>
    <qemu:arg value='-set'/>
    <qemu:arg value='device.hostdev0.driver=vfio-pci-nohotplug'/>
    <qemu:arg value='-set'/>
    <qemu:arg value='device.hostdev0.xres=1920'/>
    <qemu:arg value='-set'/>
    <qemu:arg value='device.hostdev0.yres=1080'/>
    <qemu:env name="MESA_LOADER_DRIVER_OVERRIDE" value="i965"/>
   </qemu:commandline>
   </qemu:commandline>
</domain>
</domain>
</pre>
</syntaxHighlight>
Finally use sudo virt-viewer --attach win10


== FAQ ==
== FAQ ==
Line 95: Line 122:
* No video output
* No video output


Possible solutions
** use BIOS (SeaBIOS) machine, EFI (OVMF) is not supported. You may use the following workarounds https://wiki.archlinux.org/index.php/Intel_GVT-g#Using_DMA-BUF_with_UEFI/OVMF


(libvirtd) Change main adapter type from QXL to say Cirrus
** ensure that the recent Intel graphics driver is installed in the guest
 
use BIOS (SeaBIOS) machine, UEFI (OVMF) is not supported
 
ensure that the recent Intel graphics driver is installed in the guest


* (libvirtd) "Element domain has extra content: qemu:commandline" error after editing via virsh
* (libvirtd) "Element domain has extra content: qemu:commandline" error after editing via virsh


you forgot to add <nowiki>xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'</nowiki>
** you forgot to add <nowiki>xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'</nowiki>


* (libvirtd) "no drm render node available" error in virt-manager
* (libvirtd) "no drm render node available" error in virt-manager


in virt-manager change SPICE display render node from auto to available one
** in virt-manager change SPICE display render node from auto to available one


* "write_loop: No space left on device" error when creating mdev device
* "write_loop: No space left on device" error when creating mdev device


check dmesg output for gvt related error, most likely there is not enough VRAM
** check whether available instances are left
  $ cat /sys/bus/pci/devices/0000\:00\:02.0/mdev_supported_types/i915-GVTg_V5_4/available_instances
  1
also check dmesg output for gvt related error, most likely there is not enough VRAM


== Used sources ==
* (libvirtd) VM stops immediately with no error other than "internal error: process exited while connecting to monitor"


* [https://www.kraxel.org/blog/2018/04/vgpu-display-support-finally-merged-upstream/ <em>vgpu display support</em> on a contributor (kraxel)'s blog] - this guide misses info that Windows guest requires x-igd-opregion=on parameter and also that QXL may go into conflict
** qemu might be exiting due to SIGSYS, which may be related to this bug: https://github.com/intel/gvt-linux/issues/47
* https://github.com/intel/gvt-linux/wiki/GVTg_Setup_Guide - obsoleted guide, but some parts are useful
Try disabling seccomp sandboxing in qemu like so:
* https://github.com/intel/gvt-linux/wiki/Dma_Buf_User_Guide - obsoleted guide, but some parts are useful
<syntaxHighlight lang="nix">
  virtualisation.libvirtd = {
    qemuVerbatimConfig = ''
      seccomp_sandbox = 0
    '';
  };
</syntaxHighlight>
== Useful sources ==


* https://www.kraxel.org/blog/2019/02/ramfb-display-in-qemu/ - Info about ramfb parameter
* https://lists.01.org/hyperkitty/list/igvt-g@lists.01.org/thread/LAB74CANVVRKGPBJMHULMMUFX43LRH55/ - Info about x-igd-opregion parameter
* https://www.kraxel.org/blog/2019/03/edid-support-for-qemu/ - Info about xres and yres parameters
[[Category:Video]]
[[Category:Video]]
[[Category:Virtualization]]
[[Category:Virtualization]]
Retrieved from "https://wiki.nixos.org/wiki/IGVT-g"