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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:


== Select VGPU devices ==
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
virtualisation.kvmgt.enable = true;
</nowiki>}}
... then rebuild and reboot.


Enable iGVT-g with {{file|/etc/nixos/configuration.nix|nix|<nowiki>
  boot.kernelPackages = pkgs.linuxPackages_4_16;
  virtualisation.kvmgt.enable = true;
</nowiki>}}
then rebuild and reboot. Choose virtual GPU


<pre>
After rebooting, check if the driver was successfully loaded:
$ ls /sys/bus/pci/devices/0000:00:02.0/mdev_supported_types/
i915-GVTg_V5_4/  i915-GVTg_V5_8/
</pre>


<pre>
  $ ls /sys/bus/pci/devices/0000:00:02.0/mdev_supported_types/
$ 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
... 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:


<pre>
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
$ nix run nixpkgs.libossp_uuid -c uuid
boot.extraModprobeConfig = "options i915 enable_guc=2";
a297db4a-f4c2-11e6-90f6-d3b88d6c9525
</nowiki>}}
</pre>
... 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).
 
 
Now, using <code>ls</code> you can list which variants your Intel GPU is able to virtualise:
 
  $ ls /sys/bus/pci/devices/0000:00:02.0/mdev_supported_types/
  i915-GVTg_V5_4/  i915-GVTg_V5_8/
 
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
 
Find some variant that matches your expectations (resolution, memory size etc.), note down its name, generate a random UUID:
 
  # If you're using Nix Flakes:
  $ 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 99: 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


use BIOS (SeaBIOS) machine, UEFI (OVMF) is not supported https://bugzilla.tianocore.org/show_bug.cgi?id=935
** ensure that the recent Intel graphics driver is installed in the guest
 
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 whether available instances are left
** check whether available instances are left
<pre>
  $ cat /sys/bus/pci/devices/0000\:00\:02.0/mdev_supported_types/i915-GVTg_V5_4/available_instances  
$ cat /sys/bus/pci/devices/0000\:00\:02.0/mdev_supported_types/i915-GVTg_V5_4/available_instances  
  1
1
</pre>
also check dmesg output for gvt related error, most likely there is not enough VRAM
also check dmesg output for gvt related error, most likely there is not enough VRAM


* There is no VGPU device that has resolution of my screen
* (libvirtd) VM stops immediately with no error other than "internal error: process exited while connecting to monitor"


Choose device that has higher resolution than yours than use this program in guest https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU to set resolution you need
** qemu might be exiting due to SIGSYS, which may be related to this bug: https://github.com/intel/gvt-linux/issues/47
 
Try disabling seccomp sandboxing in qemu like so:
== Used sources ==
<syntaxHighlight lang="nix">
 
  virtualisation.libvirtd = {
* [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
    qemuVerbatimConfig = ''
* https://github.com/intel/gvt-linux/wiki/GVTg_Setup_Guide - obsoleted guide, but some parts are useful
      seccomp_sandbox = 0
* https://github.com/intel/gvt-linux/wiki/Dma_Buf_User_Guide - obsoleted guide, but some parts are useful
    '';
  };
</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"