What should you install if you want a graphics card with the fastest available bus interface?

Documentation for administrators that explains how to install and configure NVIDIA Virtual GPU manager, configure virtual GPU software in pass-through mode, and install drivers on guest operating systems.

1. Introduction to NVIDIA vGPU Software

NVIDIA vGPU software is a graphics virtualization platform that provides virtual machines (VMs) access to NVIDIA GPU technology.

1.1. How NVIDIA vGPU Software Is Used

NVIDIA vGPU software can be used in several ways.

1.1.1. NVIDIA vGPU

NVIDIA Virtual GPU (vGPU™) enables multiple virtual machines (VMs) to have simultaneous, direct access to a single physical GPU, using the same NVIDIA graphics drivers that are deployed on non-virtualized operating systems. By doing this, NVIDIA vGPU provides VMs with unparalleled graphics performance and application compatibility, together with the cost-effectiveness and scalability brought about by sharing a GPU among multiple workloads.

For more information, see Installing and Configuring NVIDIA Virtual GPU Manager.

1.1.2. GPU Pass-Through

In GPU pass-through mode, an entire physical GPU is directly assigned to one VM, bypassing the NVIDA Virtual GPU Manager. In this mode of operation, the GPU is accessed exclusively by the NVIDIA driver running in the VM to which it is assigned. The GPU is not shared among VMs.

For more information, see Using GPU Pass-Through.

1.2. How this Guide Is Organized

Virtual GPU Software User Guide is organized as follows:

• This chapter introduces the architecture and features of NVIDIA vGPU software.
• Installing and Configuring NVIDIA Virtual GPU Manager provides a step-by-step guide to installing and configuring vGPU on supported hypervisors.
• Using GPU Pass-Through explains how to configure a GPU for pass-through on supported hypervisors.
• Installing the NVIDIA vGPU Software Graphics Driver explains how to install NVIDIA vGPU software graphics driver on Windows and Linux operating systems.
• Licensing an NVIDIA vGPU explains how to license NVIDIA vGPU licensed products on Windows and Linux operating systems.
• Modifying a VM's NVIDIA vGPU Configuration explains how to remove a VM’s vGPU configuration and modify GPU assignments for vGPU-enabled vMware vSphere VMs.
• Monitoring GPU Performance covers vGPU performance monitoring on XenServer.
• XenServer vGPU Management covers vGPU management on XenServer.
• XenServer Performance Tuning covers vGPU performance optimization on XenServer.
• Troubleshooting provides guidance on troubleshooting.

1.3. NVIDIA vGPU Architecture

The high-level architecture of NVIDIA vGPU is illustrated in Figure 1. Under the control of the NVIDIA Virtual GPU Manager running under the hypervisor, NVIDIA physical GPUs are capable of supporting multiple virtual GPU devices (vGPUs) that can be assigned directly to guest VMs.

Guest VMs use NVIDIA vGPUs in the same manner as a physical GPU that has been passed through by the hypervisor: an NVIDIA driver loaded in the guest VM provides direct access to the GPU for performance-critical fast paths, and a paravirtualized interface to the NVIDIA Virtual GPU Manager is used for non-performant management operations.

Figure 1. NVIDIA vGPU System Architecture

Each NVIDIA vGPU is analogous to a conventional GPU, having a fixed amount of GPU framebuffer, and one or more virtual display outputs or “heads”. The vGPU’s framebuffer is allocated out of the physical GPU’s framebuffer at the time the vGPU is created, and the vGPU retains exclusive use of that framebuffer until it is destroyed.

All vGPUs resident on a physical GPU share access to the GPU’s engines including the graphics (3D), video decode, and video encode engines.

Figure 2. NVIDIA vGPU Internal Architecture

1.4. Supported GPUs

NVIDIA vGPU is available as a licensed product on supported Tesla GPUs. For a list of recommended server platforms and supported GPUs, consult the release notes for supported hypervisors at NVIDIA Virtual GPU Software Documentation.

1.4.1. Virtual GPU Types

The number of physical GPUs that a board has depends on the board. Each physical GPU can support several different types of virtual GPU. Virtual GPU types have a fixed amount of frame buffer, number of supported display heads, and maximum resolutions. They are grouped into different series according to the different classes of workload at which they are targeted. Each series is identified by the last letter of the vGPU type name.

• Q-series virtual GPU types are targeted at designers and power users.

• B-series virtual GPU types are targeted at power users.

• A-series virtual GPU types are targeted at virtual applications users.1

The number after the board type in the vGPU type name denotes the amount of frame buffer that is allocated to a vGPU of that type. For example, a vGPU of type M60-2Q is allocated 2048 Mbytes of frame buffer on a Tesla M60 board.

Due to their differing resource requirements, the maximum number of vGPUs that can be created simultaneously on a physical GPU varies according to the vGPU type. For example, a Tesla M60 board can support up to 4 M60-2Q vGPUs on each of its two physical GPUs, for a total of 8 vGPUs, but only 2 M60-4Q vGPUs, for a total of 4 vGPUs.

Note:

NVIDIA vGPU is a licensed product on all supported GPU boards. A software license is required to enable all vGPU features within the guest VM. The type of license required depends on the vGPU type.

• Q-series virtual GPU types require a Quadro vDWS license.
• B-series virtual GPU types require a GRID Virtual PC license but can also be used with a Quadro vDWS license.
• A-series vGPU types require a GRID Virtual Applications license.

NVIDIA vGPUs with less than 1 Gbyte of frame buffer support only 1 virtual display head on a Windows 10 guest OS.

1.4.1.1. Tesla M60 Virtual GPU Types

Physical GPUs per board: 2

1.4.1.2. Tesla M10 Virtual GPU Types

Physical GPUs per board: 4

1.4.1.3. Tesla M6 Virtual GPU Types

Physical GPUs per board: 1

1.4.1.4. Since 5.1: Tesla P100 12GB Virtual GPU Types

Physical GPUs per board: 1

1.4.1.5. Tesla P100 Virtual GPU Types

Physical GPUs per board: 1

1.4.1.6. Tesla P40 Virtual GPU Types

Physical GPUs per board: 1

1.4.1.7. Tesla P6 Virtual GPU Types

Physical GPUs per board: 1

1.4.1.8. Tesla P4 Virtual GPU Types

Physical GPUs per board: 1

1.4.2. Homogeneous Virtual GPUs

This release of NVIDIA vGPU supports only homogeneous virtual GPUs. At any given time, the virtual GPUs resident on a single physical GPU must be all of the same type. However, this restriction doesn’t extend across physical GPUs on the same card. Different physical GPUs on the same card may host different types of virtual GPU at the same time, provided that the vGPU types on any one physical GPU are the same.

For example, a Tesla M60 card has two physical GPUs, and can support several types of virtual GPU. Figure 3 shows the following examples of valid and invalid virtual GPU configurations on Tesla M60:

• A valid configuration with M60-2Q vGPUs on GPU 0 and M60-4Q vGPUs on GPU 1
• A valid configuration with M60-1B vGPUs on GPU 0 and M60-2Q vGPUs on GPU 1
• An invalid configuration with mixed vGPU types on GPU 0

Figure 3. Example vGPU Configurations on Tesla M60

1.5. Guest VM Support

NVIDIA vGPU supports Windows and Linux guest VM operating systems. The supported vGPU types depend on the guest VM OS.

For details of the supported releases of Windows and Linux, and for further information on supported configurations, see the driver release notes for your hypervisor at NVIDIA Virtual GPU Software Documentation.

1.6. NVIDIA vGPU Software Features

NVIDIA vGPU software includes Quadro vDWS, GRID Virtual PC, and GRID Virtual Applications.

1.6.1. API Support on NVIDIA vGPU

NVIDIA vGPU includes support for the following APIs:

• DirectX 12, Direct2D, and DirectX Video Acceleration (DXVA)
• OpenGL 4.5
• NVIDIA vGPU software SDK (remote graphics acceleration)
• Vulkan 1.0

1.6.2. NVIDIA CUDA Toolkit and OpenCL Support on NVIDIA vGPU Software

OpenCL and CUDA applications are supported on the following NVIDIA vGPU types:

• The 8Q vGPU type on Tesla M6, Tesla M10, and Tesla M60 GPUs
• All Q-series vGPU types on the following GPUs:
  • Tesla P4
  • Tesla P6
  • Tesla P40
  • Tesla P100 SXM2
  • Tesla P100 PCIe 16 GB
  • Tesla P100 PCIe 12 GB

NVIDIA vGPU does not support the following NVIDIA CUDA Toolkit features:

• Unified Memory
• Dynamic page retirement
• Error-correcting code (ECC)
• Peer-to-peer
• GPUDirect remote direct memory access (RDMA)
• Development tools such as IDEs, debuggers, profilers, and utilities as listed under CUDA Toolkit Major Components in CUDA Toolkit 9.0 Release Notes for Windows, Linux, and Mac OS

Note: These features are supported in GPU pass-through mode and in bare-metal deployments.

For more information about NVIDIA CUDA Toolkit, see CUDA Toolkit 9.0 Documentation.

Installing and Configuring NVIDIA Virtual GPU Manager

The process for installing and configuring NVIDIA Virtual GPU Manager depends on the hypervisor that you are using. After you complete this process, you can install the display drivers for your guest OS and license any NVIDIA vGPU software licensed products that you are using.

2.1. Prerequisites for Using NVIDIA vGPU

Before proceeding, ensure that these prerequisites are met:

• You have a server platform that is capable of hosting your chosen hypervisor and NVIDIA GPUs that support NVIDIA vGPU software.
• One or more NVIDIA GPUs that support NVIDIA vGPU software is installed in your server platform.
• You have downloaded the NVIDIA vGPU software package for your chosen hypervisor, which consists of the following software:
  • NVIDIA Virtual GPU Manager for your hypervisor
  • NVIDIA vGPU software graphics drivers for supported guest operating systems
• The following software is installed according to the instructions in the software vendor's documentation:
  • Your chosen hypervisor, for example, Citrix XenServer or VMware vSphere Hypervisor (ESXi)
  • The software for managing your chosen hypervisor, for example, Citrix XenCenter management GUI, or VMware vCenter Server
  • The virtual desktop software that you will use with virtual machines (VMs) running NVIDIA Virtual GPU, for example, Citrix XenDesktop, or VMware Horizon

  Note: If you are using VMware vSphere Hypervisor (ESXi), ensure that the ESXi host on which you will configure a VM with NVIDIA vGPU is not a member of a VMware Distributed Resource Scheduler (DRS) cluster.

• A VM to be enabled with vGPU is created.

  Note: Multiple vGPUs in a VM are not supported.

• Your chosen guest OS is installed in the VM.

For information about supported hardware and software, and any known issues for this release of NVIDIA vGPU software, refer to the Release Notes for your chosen hypervisor:

• Virtual GPU Software for Citrix XenServer Release Notes
• Virtual GPU Software for VMware vSphere Release Notes

2.2. Switching the Mode of a Tesla M60 or M6 GPU

Tesla M60 and M6 GPUs support compute mode and graphics mode. NVIDIA vGPU requires GPUs that support both modes to operate in graphics mode.

Note: Only Tesla M60 and M6 GPUs require and support mode switching. Other GPUs that support NVIDIA vGPU do not require or support mode switching.

Recent Tesla M60 GPUs and M6 GPUs are supplied in graphics mode. However, your GPU might be in compute mode if it is an older Tesla M60 GPU or M6 GPU, or if its mode has previously been changed.

If your GPU supports both modes but is in compute mode, you must use the gpumodeswitch tool to change the mode of the GPU to graphics mode. If you are unsure which mode your GPU is in, use the gpumodeswitch tool to find out the mode.

For more information, see gpumodeswitch User Guide.

2.3. Installing and Configuring the NVIDIA Virtual GPU Manager for Citrix XenServer

The following topics step you through the process of setting up a single Citrix XenServer VM to use NVIDIA vGPU. After the process is complete, you can install the graphics driver for your guest OS and license any NVIDIA vGPU software licensed products that you are using.

These setup steps assume familiarity with the XenServer skills covered in XenServer Basics.

2.3.1. Installing and Updating the NVIDIA Virtual GPU Manager for XenServer

The NVIDIA Virtual GPU Manager runs in XenServer’s dom0. The NVIDIA Virtual GPU Manager for Citrix XenServer is supplied as an RPM file and as a Supplemental Pack.

CAUTION:

NVIDIA Virtual GPU Manager and Guest VM drivers must be matched from the same main driver branch. If you update vGPU Manager to a release from another driver branch, guest VMs will boot with vGPU disabled until their guest vGPU driver is updated to match the vGPU Manager version. Consult Virtual GPU Software for Citrix XenServer Release Notes for further details.

2.3.1.1. Installing the RPM package for XenServer

The RPM file must be copied to XenServer’s dom0 prior to installation (see Copying files to dom0).

1. Use the rpm command to install the package:[root@xenserver ~]# rpm -iv NVIDIA-vGPU-xenserver-7.0-384.155.x86_64.rpm Preparing packages for installation... NVIDIA-vGPU-xenserver-7.0-384.155 [root@xenserver ~]#
2. Reboot the XenServer platform:[root@xenserver ~]# shutdown –r now Broadcast message from root (pts/1) (Fri Aug 11 14:24:11 2020): The system is going down for reboot NOW! [root@xenserver ~]#

2.3.1.2. Updating the RPM Package for XenServer

If an existing NVIDIA Virtual GPU Manager is already installed on the system and you want to upgrade, follow these steps:

1. Shut down any VMs that are using NVIDIA vGPU.
2. Install the new package using the –U option to the rpm command, to upgrade from the previously installed package:[root@xenserver ~]# rpm -Uv NVIDIA-vGPU-xenserver-7.0-384.155.x86_64.rpm Preparing packages for installation... NVIDIA-vGPU-xenserver-7.0-384.155 [root@xenserver ~]#

   Note:

   You can query the version of the current NVIDIA Virtual GPU Manager package using the rpm –q command:

   [root@xenserver ~]# rpm –q NVIDIA-vGPU-xenserver-7.0-384.155 [root@xenserver ~]# If an existing NVIDIA GRID package is already installed and you don’t select the upgrade (-U) option when installing a newer GRID package, the rpm command will return many conflict errors. Preparing packages for installation... file /usr/bin/nvidia-smi from install of NVIDIA-vGPU-xenserver-7.0-384.155.x86_64 conflicts with file from package NVIDIA-vGPU-xenserver-7.0-367.137.x86_64 file /usr/lib/libnvidia-ml.so from install of NVIDIA-vGPU-xenserver-7.0-384.155.x86_64 conflicts with file from package NVIDIA-vGPU-xenserver-7.0-367.137.x86_64 ...

3. Reboot the XenServer platform:[root@xenserver ~]# shutdown –r now Broadcast message from root (pts/1) (Fri Aug 11 14:24:11 2020): The system is going down for reboot NOW! [root@xenserver ~]#

2.3.1.4. Verifying the Installation of the NVIDIA vGPU Software for XenServer Package

After the XenServer platform has rebooted, verify the installation of the NVIDIA vGPU software package for XenServer.

1. Verify that the NVIDIA vGPU software package is installed and loaded correctly by checking for the NVIDIA kernel driver in the list of kernel loaded modules.[root@xenserver ~]# lsmod | grep nvidia nvidia 9522927 0 i2c_core 20294 2 nvidia,i2c_i801 [root@xenserver ~]#
2. Verify that the NVIDIA kernel driver can successfully communicate with the NVIDIA physical GPUs in your system by running the nvidia-smi command. The nvidia-smi command is described in more detail in NVIDIA System Management Interface nvidia-smi.

Running the nvidia-smi command should produce a listing of the GPUs in your platform.

If nvidia-smi fails to run or doesn’t produce the expected output for all the NVIDIA GPUs in your system, see Troubleshooting for troubleshooting steps.

2.3.2. Configuring a Citrix XenServer VM with Virtual GPU

XenServer supports configuration and management of virtual GPUs using XenCenter, or the xe command line tool that is run in a XenServer dom0 shell. Basic configuration using XenCenter is described in the following sections. Command line management using xe is described in XenServer vGPU Management.

1. Ensure the VM is powered off.
2. Right-click the VM in XenCenter, select Properties to open the VM’s properties, and select the GPU property. The available GPU types are listed in the GPU type drop-down list:

   Figure 6. Using Citrix XenCenter to configure a VM with a vGPU

After you have configured a XenServer VM with a vGPU, start the VM, either from XenCenter or by using xe vm-start in a dom0 shell. You can view the VM’s console in XenCenter.

After the VM has booted, install the NVIDIA vGPU software graphics driver as explained in Installing the NVIDIA vGPU Software Graphics Driver.

2.4. Installing and Configuring the NVIDIA Virtual GPU Manager for VMware vSphere

You can use the NVIDIA Virtual GPU Manager for VMware vSphere to set up a VMware vSphere VM to use NVIDIA vGPU or VMware vSGA. The vGPU Manager vSphere Installation Bundles (VIBs) for VMware vSphere 6.5 and later provide vSGA and vGPU functionality in a single VIB. For VMware vSphere 6.0, vSGA and vGPU functionality are provided in separate vGPU Manager VIBs.

For NVIDIA vGPU, follow this sequence of instructions:

1. Installing and Updating the NVIDIA Virtual GPU Manager for vSphere
2. Changing the Default Graphics Type in VMware vSphere 6.5 and Later
3. Configuring a vSphere VM with NVIDIA vGPU

After configuring a vSphere VM to use NVIDIA vGPU, you can install the NVIDIA vGPU software graphics driver for your guest OS and license any NVIDIA vGPU software licensed products that you are using.

For VMware vSGA, follow this sequence of instructions:

1. Installing and Updating the NVIDIA Virtual GPU Manager for vSphere
2. Configuring a vSphere VM with VMware vSGA

Installation of the NVIDIA vGPU software graphics driver for the guest OS is not required for vSGA.

2.4.1. Installing and Updating the NVIDIA Virtual GPU Manager for vSphere

The NVIDIA Virtual GPU Manager runs on ESXi host. It is provided in the following formats:

• As a VIB file, which must be copied to the ESXi host and then installed
• As an offline bundle that you can import manually as explained in Import Patches Manually in the VMware vSphere documentation

CAUTION:

NVIDIA Virtual GPU Manager and Guest VM drivers must be matched from the same main driver branch. If you update vGPU Manager to a release from another driver branch, guest VMs will boot with vGPU disabled until their guest vGPU driver is updated to match the vGPU Manager version. Consult Virtual GPU Software for VMware vSphere Release Notes for further details.

2.4.1.1. Installing the NVIDIA Virtual GPU Manager Package for vSphere

To install the vGPU Manager VIB you need to access the ESXi host via the ESXi Shell or SSH. Refer to VMware’s documentation on how to enable ESXi Shell or SSH for an ESXi host.

Note: Before proceeding with the vGPU Manager installation make sure that all VMs are powered off and the ESXi host is placed in maintenance mode. Refer to VMware’s documentation on how to place an ESXi host in maintenance mode.

1. Use the esxcli command to install the vGPU Manager package:[root@esxi:~] esxcli software vib install -v directory/NVIDIA-vGPU-VMware_ESXi_6.0_Host_Driver_384.155-1OEM.600.0.0.2159203.vib Installation Result Message: Operation finished successfully. Reboot Required: false VIBs Installed: NVIDIA-vGPU-VMware_ESXi_6.0_Host_Driver_384.155-1OEM.600.0.0.2159203 VIBs Removed: VIBs Skipped:

   directory is the absolute path to the directory that contains the VIB file. You must specify the absolute path even if the VIB file is in the current working directory.

2. Reboot the ESXi host and remove it from maintenance mode.

2.4.1.2. Updating the NVIDIA Virtual GPU Manager Package for vSphere

Update the vGPU Manager VIB package if you want to install a new version of NVIDIA Virtual GPU Manager on a system where an existing version is already installed.

To update the vGPU Manager VIB you need to access the ESXi host via the ESXi Shell or SSH. Refer to VMware’s documentation on how to enable ESXi Shell or SSH for an ESXi host.

Note: Before proceeding with the vGPU Manager update, make sure that all VMs are powered off and the ESXi host is placed in maintenance mode. Refer to VMware’s documentation on how to place an ESXi host in maintenance mode

1. Use the esxcli command to update the vGPU Manager package:[root@esxi:~] esxcli software vib update -v directory/NVIDIA-vGPU-VMware_ESXi_6.0_Host_Driver_384.155-1OEM.600.0.0.2159203.vib Installation Result    Message: Operation finished successfully.    Reboot Required: false    VIBs Installed: NVIDIA-vGPU-VMware_ESXi_6.0_Host_Driver_384.155-1OEM.600.0.0.2159203    VIBs Removed: NVIDIA-vGPU-VMware_ESXi_6.0_Host_Driver_367.137-1OEM.600.0.0.2159203    VIBs Skipped:

   directory is the path to the directory that contains the VIB file.

2. Reboot the ESXi host and remove it from maintenance mode.

2.4.1.3. Verifying the Installation of the NVIDIA vGPU Software Package for vSphere

After the ESXi host has rebooted, verify the installation of the NVIDIA vGPU software package for vSphere.

1. Verify that the NVIDIA vGPU software package installed and loaded correctly by checking for the NVIDIA kernel driver in the list of kernel loaded modules.[root@esxi:~] vmkload_mod -l | grep nvidia nvidia 5 8420
2. If the NVIDIA driver is not listed in the output, check dmesg for any load-time errors reported by the driver.
3. Verify that the NVIDIA kernel driver can successfully communicate with the NVIDIA physical GPUs in your system by running the nvidia-smi command. The nvidia-smi command is described in more detail in NVIDIA System Management Interface nvidia-smi.

Running the nvidia-smi command should produce a listing of the GPUs in your platform.

If nvidia-smi fails to report the expected output for all the NVIDIA GPUs in your system, see Troubleshooting for troubleshooting steps.

2.4.2. Changing the Default Graphics Type in VMware vSphere 6.5 and Later

The vGPU Manager VIBs for VMware vSphere 6.5 and later provide vSGA and vGPU functionality in a single VIB. After this VIB is installed, the default graphics type is Shared, which provides vSGA functionality. To enable vGPU support for VMs in VMware vSphere 6.5, you must change the default graphics type to Shared Direct. If you do not change the default graphics type, VMs to which a vGPU is assigned fail to start and the following error message is displayed:

Note:

If you are using a supported version of VMware vSphere earlier than 6.5, or are configuring a VM to use vSGA, omit this task.

Change the default graphics type before configuring vGPU. Output from the VM console in the VMware vSphere Web Client is not available for VMs that are running vGPU.

Before changing the default graphics type, ensure that the ESXi host is running and that all VMs on the host are powered off.

1. Log in to vCenter Server by using the vSphere Web Client.
2. In the navigation tree, select your ESXi host and click the Configure tab.
3. From the menu, choose Graphics and then click the Host Graphics tab.
4. On the Host Graphics tab, click Edit.

   Figure 7. Shared default graphics type

5. In the Edit Host Graphics Settings dialog box that opens, select Shared Direct and click OK.

   Figure 8. Host graphics settings for vGPU

   After you click OK, the default graphics type changes to Shared Direct.

6. Click the Graphics Devices tab to verify the configured type of each physical GPU on which you want to configure vGPU. The configured type of each physical GPU must be Shared Direct. For any physical GPU for which the configured type is Shared, change the configured type as follows:
   1. On the Graphics Devices tab, select the physical GPU and click the Edit icon.

      Figure 9. Shared graphics type

   2. In the Edit Graphics Device Settings dialog box that opens, select Shared Direct and click OK.

   Figure 10. Graphics device settings for a physical GPU

7. Restart the ESXi host or stop and restart the Xorg service and nv-hostengine on the ESXi host.

   To stop and restart the Xorg service and nv-hostengine, perform these steps:

   1. Stop the Xorg service.[root@esxi:~] /etc/init.d/xorg stop
   2. Stop nv-hostengine.[root@esxi:~] nv-hostengine -t
   3. Wait for 1 second to allow nv-hostengine to stop.
   4. Start nv-hostengine.[root@esxi:~] nv-hostengine -d
   5. Start the Xorg service.[root@esxi:~] /etc/init.d/xorg start
8. In the Graphics Devices tab of the VMware vCenter Web UI, confirm that the active type and the configured type of each physical GPU are Shared Direct.

   Figure 11. Shared direct graphics type

After changing the default graphics type, configure vGPU as explained in Configuring a vSphere VM with NVIDIA vGPU.

See also the following topics in the VMware vSphere documentation:

• Log in to vCenter Server by Using the vSphere Web Client
• Configuring Host Graphics

2.4.3. Configuring a vSphere VM with NVIDIA vGPU

CAUTION:

Output from the VM console in the VMware vSphere Web Client is not available for VMs that are running vGPU. Make sure that you have installed an alternate means of accessing the VM (such as VMware Horizon or a VNC server) before you configure vGPU.

VM console in vSphere Web Client will become active again once the vGPU parameters are removed from the VM’s configuration.

Note: If you are configuring a VM to use VMware vSGA, omit this task.

1. Open the vCenter Web UI.
2. In the vCenter Web UI, right-click the VM and choose Edit Settings.
3. Click the Virtual Hardware tab.
4. In the New device list, select Shared PCI Device and click Add. The PCI device field should be auto-populated with NVIDIA GRID vGPU.

   Figure 12. VM settings for vGPU

5. From the GPU Profile drop-down menu, choose the type of vGPU you want to configure and click OK.
6. Ensure that VMs running vGPU have all their memory reserved:
   1. Select Edit virtual machine settings from the vCenter Web UI.
   2. Expand the Memory section and click Reserve all guest memory (All locked).

After you have configured a vSphere VM with a vGPU, start the VM. VM console in vSphere Web Client is not supported in this vGPU release. Therefore, use VMware Horizon or VNC to access the VM’s desktop.

After the VM has booted, install the NVIDIA vGPU software graphics driver as explained in Installing the NVIDIA vGPU Software Graphics Driver.

2.4.4. Configuring a vSphere VM with VMware vSGA

Virtual Shared Graphics Acceleration (vSGA) is a feature of VMware vSphere that enables multiple virtual machines to share the physical GPUs on ESXi hosts.

Note: If you are configuring a VM to use NVIDIA vGPU, omit this task.

Before configuring a vSphere VM with vSGA, ensure that these prerequisites are met:

• VMware tools are installed on the VM.
• The VM is powered off.
• The NVIDIA Virtual GPU Manager package for vSphere is installed.

1. Open the vCenter Web UI.
2. In the vCenter Web UI, right-click the VM and choose Edit Settings.
3. Click the Virtual Hardware tab.
4. In the device list, expand the Video card node and set the following options:
   1. Select the Enable 3D support option.
   2. Set the 3D Renderer to Hardware.
   For more information, see Configure 3D Graphics and Video Cards in the VMware Horizon documentation.
5. Start the VM.
6. After the VM has booted, verify that the VM has been configured correctly with vSGA.
   1. Under the Display Adapter section of Device Manager, confirm that VMware SVGA 3D is listed.
   2. Verify that the virtual machine is using the GPU card.# gpuvm

      The output from the command is similar to the following example for a VM named samplevm1:

      Xserver unix:0, GPU maximum memory 4173824KB pid 21859, VM samplevm1, reserved 131072KB of GPU memory. GPU memory left 4042752KB.

      The memory reserved for the VM and the GPU maximum memory depend on the GPU installed in the host and the 3D memory allocated to the virtual machine.

Installation of the NVIDIA vGPU software graphics driver for the guest OS is not required for vSGA.

2.5. Disabling ECC Memory

Tesla M60, Tesla M6, and GPUs based on the Pascal GPU architecture, for example Tesla P100 or Tesla P4, support error correcting code (ECC) memory for improved data integrity. Tesla M60 and M6 GPUs in graphics mode are supplied with ECC memory disabled by default, but it may subsequently be enabled using nvidia-smi. GPUs based on the Pascal GPU architecture are supplied with ECC memory enabled.

However, NVIDIA vGPU does not support ECC memory. If ECC memory is enabled, NVIDIA vGPU fails to start. Therefore, you must ensure that ECC memory is disabled on all GPUs if you are using NVIDIA vGPU.

Before you begin, ensure that NVIDIA Virtual GPU Manager is installed on your hypervisor.

1. Use nvidia-smi to list the status of all GPUs, and check for ECC noted as enabled on GPUs.# nvidia-smi -q ==============NVSMI LOG============== Timestamp : Tue Dec 19 18:36:45 2017 Driver Version : 384.99 Attached GPUs : 1 GPU 0000:02:00.0 [...] Ecc Mode Current : Enabled Pending : Enabled [...]
2. Change the ECC status to off on each GPU for which ECC is enabled.
   • If you want to change the ECC status to off for all GPUs on your host machine, run this command:# nvidia-smi -e 0
   • If you want to change the ECC status to off for a specific GPU, run this command:# nvidia-smi -i id -e 0

     id is the index of the GPU as reported by nvidia-smi.

     This example disables ECC for the GPU with index 0000:02:00.0.

     # nvidia-smi -i 0000:02:00.0 -e 0
3. Reboot the host.
4. Confirm that ECC is now disabled for the GPU.# nvidia—smi —q ==============NVSMI LOG============== Timestamp : Tue Dec 19 18:37:53 2017 Driver Version : 384.99 Attached GPUs : 1 GPU 0000:02:00.0 [...] Ecc Mode Current : Disabled Pending : Disabled [...]

If you later need to enable ECC on your GPUs, run one of the following commands:

• If you want to change the ECC status to on for all GPUs on your host machine, run this command:# nvidia-smi -e 1
• If you want to change the ECC status to on for a specific GPU, run this command:# nvidia-smi -i id -e 1

  id is the index of the GPU as reported by nvidia-smi.

  This example enables ECC for the GPU with index 0000:02:00.0.

  # nvidia-smi -i 0000:02:00.0 -e 1

After changing the ECC status to on, reboot the host.

3. Using GPU Pass-Through

GPU pass-through is used to directly assign an entire physical GPU to one VM, bypassing the NVIDIA Virtual GPU Manager. In this mode of operation, the GPU is accessed exclusively by the NVIDIA driver running in the VM to which it is assigned; the GPU is not shared among VMs.

In pass-through mode, GPUs based on NVIDIA GPU architectures after the Maxwell architecture support error-correcting code (ECC).

GPU pass-through can be used in a server platform alongside NVIDIA vGPU, with some restrictions:

• A physical GPU can host NVIDIA vGPUs, or can be used for pass-through, but cannot do both at the same time. Some hypervisors, for example VMware vSphere ESXi, require a host reboot to change a GPU from pass-through mode to vGPU mode.
• The performance of a physical GPU passed through to a VM can be monitored only from within the VM itself. Such a GPU cannot be monitored by tools that operate through the hypervisor, such as XenCenter or nvidia-smi (see Monitoring GPU Performance).

• The following BIOS settings must be enabled on your server platform:

  • VT-D/IOMMU
  • SR-IOV in Advanced Options

3.1. Using GPU Pass-Through on Citrix XenServer

You can configure a GPU for pass-through on Citrix XenServer by using XenCenter or by using the xe command.

The following additional restrictions apply when GPU pass-through is used in a server platform alongside NVIDIA vGPU:

• The performance of a physical GPU passed through to a VM cannot be monitored through XenCenter.
• nvidia-smi in dom0 no longer has access to the GPU.
• Pass-through GPUs do not provide console output through XenCenter’s VM Console tab. Use a remote graphics connection directly into the VM to access the VM’s OS.

3.1.2. Configuring a VM for GPU Pass Through by Using xe

Create a vgpu object with the passthrough vGPU type:

CAUTION:

Do not assign pass-through GPUs using the legacy other-config:pci parameter setting. This mechanism is not supported alongside the XenCenter UI and xe vgpu mechanisms, and attempts to use it may lead to undefined results.

After configuring a Citrix XenServer VM for GPU pass through, install the NVIDIA graphics driver in the guest OS on the VM as explained in Installing the NVIDIA vGPU Software Graphics Driver.

3.2. Using GPU Pass-Through on Red Hat Enterprise Linux KVM

You can configure a GPU for pass-through on Red Hat Enterprise Linux Kernel-based Virtual Machine (KVM) by using any of the following tools:

• The Virtual Machine Manager (virt-manager) graphical tool
• The virsh command
• The QEMU command line

Before configuring a GPU for pass-through on Red Hat Enterprise Linux KVM, ensure that the following prerequisites are met:

• Red Hat Enterprise Linux KVM is installed.
• A virtual disk has been created.

  Note: Do not create any virtual machines in /root.

• A virtual machine has been created.

3.2.1. Configuring a VM for GPU Pass-Through by Using Virtual Machine Manager (virt-manager)

For more information about using Virtual Machine Manager, see the following topics in the documentation for Red Hat Enterprise Linux 7:

• Managing Guests with the Virtual Machine Manager (virt-manager)
• Starting virt-manager
• Assigning a PCI Device with virt-manager

1. Start virt-manager.
2. In the virt-manager main window, select the VM that you want to configure for pass-through.
3. From the Edit menu, choose Virtual Machine Details.
4. In the virtual machine hardware information window that opens, click Add Hardware.
5. In the Add New Virtual Hardware dialog box that opens, in the hardware list on the left, select PCI Host Device.
6. From the Host Device list that appears, select the GPU that you want to assign to the VM and click Finish.

If you want to remove a GPU from the VM to which it is assigned, in the virtual machine hardware information window, select the GPU and click Remove.

After configuring a for GPU pass through, install the NVIDIA graphics driver in the guest OS on the VM as explained in Installing the NVIDIA vGPU Software Graphics Driver.

3.2.2. Configuring a VM for GPU Pass-Through by Using virsh

For more information about using virsh, see the following topics in the documentation for Red Hat Enterprise Linux 7:

• Managing Guest Virtual Machines with virsh
• Assigning a PCI Device with virsh

1. Verify that the vfio-pci module is loaded.# lsmod | grep vfio-pci
2. Obtain the PCI device bus/device/function (BDF) of the GPU that you want to assign in pass-through mode to a VM.# lspci | grep NVIDIA

   The NVIDIA GPUs listed in this example have the PCI device BDFs 85:00.0 and 86:00.0.

   # lspci | grep NVIDIA 85:00.0 VGA compatible controller: NVIDIA Corporation GM204GL [Tesla M60] (rev a1) 86:00.0 VGA compatible controller: NVIDIA Corporation GM204GL [Tesla M60] (rev a1)
3. Obtain the full identifier of the GPU from its PCI device BDF.# virsh nodedev-list --cap pci| grep transformed-bdftransformed-bdfThe PCI device BDF of the GPU with the colon and the period replaced with underscores, for example, 85_00_0.

   This example obtains the full identifier of the GPU with the PCI device BDF 85:00.0.

   # virsh nodedev-list --cap pci| grep 85_00_0 pci_0000_85_00_0
4. Obtain the domain, bus, slot, and function of the GPU.virsh nodedev-dumpxml full-identifier| egrep 'domain|bus|slot|function'full-identifierThe full identifier of the GPU that you obtained in the previous step, for example, pci_0000_85_00_0.

   This example obtains the domain, bus, slot, and function of the GPU with the PCI device BDF 85:00.0.

   # virsh nodedev-dumpxml pci_0000_85_00_0| egrep 'domain|bus|slot|function' <domain>0x0000</domain> <bus>0x85</bus> <slot>0x00</slot> <function>0x0</function> <address domain='0x0000' bus='0x85' slot='0x00' function='0x0'/>
5. In virsh, open for editing the XML file of the VM that you want to assign the GPU to.# virsh edit vm-namevm-nameThe name of the VM to that you want to assign the GPU to.
6. Add a device entry in the form of an address element inside the source element to assign the GPU to the guest VM. You can optionally add a second address element after the source element to set a fixed PCI device BDF for the GPU in the guest operating system. <hostdev mode='subsystem' type='pci' managed='yes'> <source> <address domain='domain' bus='bus' slot='slot' function='function'/> </source> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </hostdev>domain busslotfunctionThe domain, bus, slot, and function of the GPU, which you obtained in the previous step.

   This example adds a device entry for the GPU with the PCI device BDF 85:00.0 and fixes the BDF for the GPU in the guest operating system.

   <hostdev mode='subsystem' type='pci' managed='yes'> <source> <address domain='0x0000' bus='0x85' slot='0x00' function='0x0'/> </source> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </hostdev>
7. Start the VM that you assigned the GPU to.# virsh start vm-namevm-nameThe name of the VM that you assigned the GPU to.

After configuring a for GPU pass through, install the NVIDIA graphics driver in the guest OS on the VM as explained in Installing the NVIDIA vGPU Software Graphics Driver.

3.2.3. Configuring a VM for GPU Pass-Through by Using the QEMU Command Line

1. Obtain the PCI device bus/device/function (BDF) of the GPU that you want to assign in pass-through mode to a VM.# lspci | grep NVIDIA

   The NVIDIA GPUs listed in this example have the PCI device BDFs 85:00.0 and 86:00.0.

   # lspci | grep NVIDIA 85:00.0 VGA compatible controller: NVIDIA Corporation GM204GL [Tesla M60] (rev a1) 86:00.0 VGA compatible controller: NVIDIA Corporation GM204GL [Tesla M60] (rev a1)
2. Add the following option to the QEMU command line:-device vfio-pci,host=bdfbdfThe PCI device BDF of the GPU that you want to assign in pass-through mode to a VM, for example, 85:00.0.

   This example assigns the GPU with the PCI device BDF 85:00.0 in pass-through mode to a VM.

   -device vfio-pci,host=85:00.0

After configuring a for GPU pass through, install the NVIDIA graphics driver in the guest OS on the VM as explained in Installing the NVIDIA vGPU Software Graphics Driver.

3.3. Using GPU Pass-Through on Microsoft Windows Server

On supported versons of Microsoft Windows Server with Hyper-V role, you can use Discrete Device Assignment (DDA) to enable a VM to access a GPU directly.

3.3.1. Assigning a GPU to a VM on Microsoft Windows Server with Hyper-V

Perform this task in Windows PowerShell. If you do not know the location path of the GPU that you want to assign to a VM, use Device Manager to obtain it.

Ensure that the following prerequisites are met:

• Windows Server with Desktop Experience and the Hyper-V role are installed and configured on your server platform, and a VM is created.

  For instructions, refer to the following articles on the Microsoft technical documentation site:

  • Install Server with Desktop Experience
  • Install the Hyper-V role on Windows Server
  • Create a virtual switch for Hyper-V virtual machines
  • Create a virtual machine in Hyper-V
• The guest OS is installed in the VM.
• The VM is powered off.

1. Obtain the location path of the GPU that you want to assign to a VM.
   1. In the device manager, context-click the GPU and from the menu that pops up, choose Properties.
   2. In the Properties window that opens, click the Details tab and in the Properties drop-down list, select Location paths.

   An example location path is as follows:

   PCIROOT(80)#PCI(0200)#PCI(0000)#PCI(1000)#PCI(0000)
2. Dismount the GPU from host to make it unavailable to the host so that it can be used solely by the VM.Dismount-VMHostAssignableDevice -LocationPath gpu-device-location -forcegpu-device-locationThe location path of the GPU that you obtained in the previous step.

   This example dismounts the GPU at the location path PCIROOT(80)#PCI(0200)#PCI(0000)#PCI(1000)#PCI(0000).

   Dismount-VMHostAssignableDevice -LocationPath "PCIROOT(80)#PCI(0200)#PCI(0000)#PCI(1000)#PCI(0000)" -force
3. Assign the GPU that you dismounted in the previous step to the VM.Add-VMAssignableDevice -LocationPath gpu-device-location -VMName vm-namegpu-device-locationThe location path of the GPU that you dismounted in the previous step. vm-nameThe name of the VM to which you are attaching the GPU.

   Note: You can assign a pass-through GPU to only one virtual machine at a time.

   This example assigns the GPU at the location path PCIROOT(80)#PCI(0200)#PCI(0000)#PCI(1000)#PCI(0000) to the VM VM1.

   Add-VMAssignableDevice -LocationPath "PCIROOT(80)#PCI(0200)#PCI(0000)#PCI(1000)#PCI(0000)" -VMName VM1
4. Power on the VM. The guest OS should now be able to use the GPU.

After assigning a GPU to a VM, install the NVIDIA graphics driver in the guest OS on the VM as explained in Installing the NVIDIA vGPU Software Graphics Driver.

3.3.2. Returning a GPU to the Host OS from a VM on Windows Server with Hyper-V

Perform this task in the Windows PowerShell.

1. List the GPUs that are currently assigned to the virtual machine (VM).Get-VMAssignableDevice -VMName vm-namevm-nameThe name of the VM whose assigned GPUs you want to list.
2. Shut down the VM to which the GPU is assigned.
3. Remove the GPU from VM to which it is assigned.Remove-VMAssignableDevice –LocationPath gpu-device-location -VMName vm-namegpu-device-location The location path of the GPU that you are removing, which you obtained in the previous step. vm-nameThe name of the VM from which you are removing the GPU.

   This example removes the GPU at the location path PCIROOT(80)#PCI(0200)#PCI(0000)#PCI(1000)#PCI(0000) from the VM VM1.

   Remove-VMAssignableDevice –LocationPath "PCIROOT(80)#PCI(0200)#PCI(0000)#PCI(1000)#PCI(0000)" -VMName VM1 After the GPU is removed from the VM, it is unavailable to the host operating system (OS) until you remount it on the host OS.
4. Remount the GPU on the host OS.Mount-VMHostAssignableDevice –LocationPath gpu-device-locationgpu-device-locationThe location path of the GPU that you are remounting, which you specified in the previous step to remove the GPU from the VM.

   This example remounts the GPU at the location path PCIROOT(80)#PCI(0200)#PCI(0000)#PCI(1000)#PCI(0000) on the host OS.

   Mount-VMHostAssignableDevice -LocationPath "PCIROOT(80)#PCI(0200)#PCI(0000)#PCI(1000)#PCI(0000)" The host OS should now be able to use the GPU.

3.4. Using GPU Pass-Through on VMware vSphere

On VMware vSphere, you can use Virtual Dedicated Graphics Acceleration (vDGA) to enable a VM to access a GPU directly. vDGA is a feature of VMware vSphere that dedicates a single physical GPU on an ESXi host to a single virtual machine.

Before configuring a vSphere VM with vDGA, ensure that these prerequisites are met

• The VM and the ESXi host are configured as explained in Preparing for vDGA Capabilities in the VMware Horizon documentation.
• The VM is powered off.

1. Open the vCenter Web UI.
2. In the vCenter Web UI, right-click the ESXi host and choose Settings.
3. From the Hardware menu, choose PCI Devices and click the Edit icon.
4. Select all NVIDIA GPUs and click OK.
5. Reboot the ESXi host.
6. After the ESXi host has booted, right-click the VM and choose Edit Settings.
7. From the New Device menu, choose PCI Device and click Add.
8. On the page that opens, from the New Device drop-down list, select the GPU.
9. Click Reserve all memory and click OK.
10. Start the VM.

For more information about vDGA, see the following topics in the VMware Horizon documentation:

• Configuring 3D Rendering for Desktops
• Configure RHEL 6 for vDGA

After configuring a vSphere VM with vDGA, install the NVIDIA graphics driver in the guest OS on the VM as explained in Installing the NVIDIA vGPU Software Graphics Driver.

4. Installing the NVIDIA vGPU Software Graphics Driver

The process for installing the NVIDIA vGPU software graphics driver depends on the OS that you are using. However, for any OS, the process for installing the driver is the same in a VM configured with vGPU, in a VM that is running pass-through GPU, or on a physical host in a bare-metal deployment.

After you install the NVIDIA vGPU software graphics driver, you can license any NVIDIA vGPU software licensed products that you are using.

4.1. Installing the NVIDIA vGPU Software Graphics Driver on Windows

Installation in a VM: After you create a Windows VM on the hypervisor and boot the VM, the VM should boot to a standard Windows desktop in VGA mode at 800×600 resolution. You can use the Windows screen resolution control panel to increase the resolution to other standard resolutions, but to fully enable GPU operation, the NVIDIA vGPU software graphics driver must be installed. Windows guest VMs are supported on all NVIDIA vGPU types.

Installation on bare metal: When the physical host is booted before the NVIDIA vGPU software graphics driver is installed, boot and the primary display are handled by an on-board graphics adapter. To install the NVIDIA vGPU software graphics driver, access the Windows desktop on the host by using a display connected through the on-board graphics adapter.

The procedure for installing the driver is the same in a VM and on bare metal.

1. Copy the 32-bit or 64-bit NVIDIA Windows driver package to the guest VM or physical host where you are installing the driver.
2. Execute the package to unpack and run the driver installer.

   Figure 14. NVIDIA driver installation

3. Click through the license agreement.
4. Select Express Installation and click NEXT. After the driver installation is complete, the installer may prompt you to restart the platform.
5. If prompted to restart the platform, do one of the following:
   • Select Restart Now to reboot the VM or physical host.
   • Exit the installer and reboot the VM or physical host when you are ready.
   After the VM or physical host restarts, it boots to a Windows desktop.
6. Verify that the NVIDIA driver is running.
   1. Right-click on the desktop.
   2. From the menu that opens, choose NVIDIA Control Panel.
   3. In the NVIDIA Control Panel, from the Help menu, choose System Information.

      NVIDIA Control Panel reports the vGPU or physical GPU that is being used, its capabilities, and the NVIDIA driver version that is loaded.

      Figure 15. Verifying NVIDIA driver operation using NVIDIA Control Panel

Installation in a VM: After you install the NVIDIA vGPU software graphics driver, you can license any NVIDIA vGPU software licensed products that you are using. For instructions, refer to Virtual GPU Client Licensing User Guide.

Installation on bare metal: After you install the NVIDIA vGPU software graphics driver, complete the bare-metal deployment as explained in Bare-Metal Deployment.

4.2. Installing the NVIDIA vGPU Software Graphics Driver on Linux

Installation in a VM: After you create a Linux VM on the hypervisor and boot the VM, install the NVIDIA vGPU software graphics driver in the VM to fully enable GPU operation. 64-bit Linux guest VMs are supported only on Q-series NVIDIA vGPUs.

Installation on bare metal: When the physical host is booted before the NVIDIA vGPU software graphics driver is installed, the vesa Xorg driver starts the X server. If a primary display device is connected to the host, use the device to access the desktop. Otherwise, use secure shell (SSH) to log in to the host from a remote host. If the Nouveau driver for NVIDIA graphics cards is present, disable it before installing the NVIDIA vGPU software graphics driver.

The procedure for installing the driver is the same in a VM and on bare metal.

Installation of the NVIDIA vGPU software graphics driver for Linux requires:

• Compiler toolchain
• Kernel headers

1. Copy the NVIDIA vGPU software Linux driver package, for example NVIDIA-Linux_x86_64-384.155-grid.run, to the guest VM or physical host where you are installing the driver.
2. Before attempting to run the driver installer, exit the X server and terminate all OpenGL applications.
   • On Red Hat Enterprise Linux and CentOS systems, exit the X server by transitioning to runlevel 3:[nvidia@localhost ~]$ sudo init 3
   • On Ubuntu platforms, do the following:
     1. Use CTRL-ALT-F1 to switch to a console login prompt.
     2. Log in and shut down the display manager:[nvidia@localhost ~]$ sudo service lightdm stop
3. From a console shell, run the driver installer as the root user.sudo sh ./ NVIDIA-Linux_x86_64-352.47-grid.run The installer should launch and display the driver license agreement as shown in Figure 16:

   Figure 16. NVIDIA Linux driver installer

4. Accept the license agreement to continue with the driver installation. In some instances the installer may fail to detect the installed kernel headers and sources. In this situation, re-run the installer, specifying the kernel source path with the --kernel-source-path option: sudo sh ./ NVIDIA-Linux_x86_64-352.47-grid.run \ –kernel-source-path=/usr/src/kernels/3.10.0-229.11.1.el7.x86_64
5. When prompted, accept the option to update the X configuration file (xorg.conf) settings as shown in Figure 17:

   Figure 17. Update xorg.conf settings

6. Once installation has completed, select OK to exit the installer.
7. Verify that the NVIDIA driver is operational.
   1. Reboot the system and log in.
   2. Run nvidia-settings.[nvidia@localhost ~]$ nvidia-settings The NVIDIA X Server Settings dialog box opens to show that the NVIDIA driver is operational as shown in Figure 18.

      Figure 18. Verifying operation with nvidia-settings

Installation in a VM: After you install the NVIDIA vGPU software graphics driver, you can license any NVIDIA vGPU software licensed products that you are using. For instructions, refer to Virtual GPU Client Licensing User Guide.

Installation on bare metal: After you install the NVIDIA vGPU software graphics driver, complete the bare-metal deployment as explained in Bare-Metal Deployment.

5. Licensing an NVIDIA vGPU

NVIDIA vGPU is a licensed product. When booted on a supported GPU, a vGPU runs at reduced capability until a license is acquired.

The performance of an unlicensed vGPU is restricted as follows:

• Screen resolution is limited to no higher than 1280×1024.
• Frame rate is capped at 3 frames per second.
• GPU resource allocations are limited, which will prevent some applications from running correctly.
• On vGPUs that support CUDA, CUDA is disabled.

These restrictions are removed when a license is acquired.

After you license NVIDIA vGPU, the VM that is set up to use NVIDIA vGPU is capable of running the full range of DirectX and OpenGL graphics applications.

If licensing is configured, the virtual machine (VM) obtains a license from the license server when a vGPU is booted on these GPUs. The VM retains the license until it is shut down. It then releases the license back to the license server. Licensing settings persist across reboots and need only be modified if the license server address changes, or the VM is switched to running GPU pass through.

Note: For complete information about configuring and using NVIDIA vGPU software licensed features, including vGPU, refer to Virtual GPU Client Licensing User Guide.

5.1. Licensing an NVIDIA vGPU on Windows

Perform this task from the guest VM to which the vGPU is assigned.

The NVIDIA Control Panel tool that you use to perform this task detects that a vGPU is assigned to the VM and, therefore, provides no options for selecting the license type. After you license the vGPU, NVIDIA vGPU software automatically selects the correct type of license based on the vGPU type.

1. Open NVIDIA Control Panel:
   • Right-click on the Windows desktop and select NVIDIA Control Panel from the menu.
   • Open Windows Control Panel and double-click the NVIDIA Control Panel icon.
2. In NVIDIA Control Panel, select the Manage License task in the Licensing section of the navigation pane.

   Note: If the Licensing section and Manage License task are not displayed in NVIDIA Control Panel, the system has been configured to hide licensing controls in NVIDIA Control Panel. For information about registry settings, see Virtual GPU Client Licensing User Guide.

   The Manage License task pane shows that NVIDIA vGPU is currently unlicensed.

   Figure 19. Managing vGPU licensing in NVIDIA Control Panel

3. In the Primary License Server field, enter the address of your primaryNVIDIA vGPU software License Server. The address can be a fully-qualified domain name such as gridlicense1.example.com, or an IP address such as 10.31.20.45. If you have only one license server configured, enter its address in this field.
4. Leave the Port Number field under the Primary License Server field unset. The port defaults to 7070, which is the default port number used by NVIDIA vGPU software License Server.
5. In the Secondary License Server field, enter the address of your secondary NVIDIA vGPU software License Server. If you have only one license server configured, leave this field unset. The address can be a fully-qualified domain name such as gridlicense2.example.com, or an IP address such as 10.31.20.46.
6. Leave the Port Number field under the Secondary License Server field unset. The port defaults to 7070, which is the default port number used by NVIDIA vGPU software License Server.
7. Click Apply to assign the settings. The system requests the appropriate license for the current vGPU from the configured license server.

The vGPU within the VM should now exhibit full frame rate, resolution, and display output capabilities. The VM is now capable of running the full range of DirectX and OpenGL graphics applications.

If the system fails to obtain a license, see Virtual GPU Client Licensing User Guide for guidance on troubleshooting.

5.2. Licensing an NVIDIA vGPU on Linux

Perform this task from the guest VM to which the vGPU is assigned.

The NVIDIA X Server Settings tool that you use to perform this task detects that a vGPU is assigned to the VM and, therefore, provides no options for selecting the license type. After you license the vGPU, NVIDIA vGPU software automatically selects the correct type of license based on the vGPU type.

1. Start NVIDIA X Server Settings by using the method for launching applications provided by your Linux distribution. For example, on Ubuntu Desktop, open the Dash, search for NVIDIA X Server Settings, and click the NVIDIA X Server Settings icon.
2. In the NVIDIA X Server Settings window that opens, click Manage GRID License. The License Edition section of the NVIDIA X Server Settings window shows that NVIDIA vGPU is currently unlicensed.
3. In the Primary Server field, enter the address of your primary NVIDIA vGPU software License Server. The address can be a fully-qualified domain name such as gridlicense1.example.com, or an IP address such as 10.31.20.45. If you have only one license server configured, enter its address in this field.
4. Leave the Port Number field under the Primary Server field unset. The port defaults to 7070, which is the default port number used by NVIDIA vGPU software License Server.
5. In the Secondary Server field, enter the address of your secondary NVIDIA vGPU software License Server. If you have only one license server configured, leave this field unset. The address can be a fully-qualified domain name such as gridlicense2.example.com, or an IP address such as 10.31.20.46.
6. Leave the Port Number field under the Secondary Server field unset. The port defaults to 7070, which is the default port number used by NVIDIA vGPU software License Server.
7. Click Apply to assign the settings. The system requests the appropriate license for the current vGPU from the configured license server.

The vGPU within the VM should now exhibit full frame rate, resolution, and display output capabilities. The VM is now capable of running the full range of DirectX and OpenGL graphics applications.

If the system fails to obtain a license, see Virtual GPU Client Licensing User Guide for guidance on troubleshooting.

6. Modifying a VM's NVIDIA vGPU Configuration

You can modify a VM's NVIDIA vGPU configuration by removing the NVIDIA vGPU configuration from a VM or by modifying GPU allocation policy.

6.1. Removing a VM’s NVIDIA vGPU Configuration

Remove a VM’s NVIDIA vGPU configuration when you no longer require the VM to use a virtual GPU.

6.1.1. Removing a XenServer VM’s vGPU configuration

You can remove a virtual GPU assignment from a VM, such that it no longer uses a virtual GPU, by using either XenCenter or the xe command.

Note: The VM must be in the powered-off state in order for its vGPU configuration to be modified or removed.

6.1.1.2. Removing a VM’s vGPU configuration by using xe

1. Use vgpu-list to discover the vGPU object UUID associated with a given VM:[root@xenserver ~]# xe vgpu-list vm-uuid=e71afda4-53f4-3a1b-6c92-a364a7f619c2 uuid ( RO) : c1c7c43d-4c99-af76-5051-119f1c2b4188 vm-uuid ( RO): e71afda4-53f4-3a1b-6c92-a364a7f619c2 gpu-group-uuid ( RO): d53526a9-3656-5c88-890b-5b24144c3d96
2. Use vgpu-destroy to delete the virtual GPU object associated with the VM:[root@xenserver ~]# xe vgpu-destroy uuid=c1c7c43d-4c99-af76-5051-119f1c2b4188 [root@xenserver ~]#

6.1.2. Removing a vSphere VM’s vGPU Configuration

To remove a vSphere vGPU configuration from a VM:

1. Select Edit settings after right-clicking on the VM in the vCenter Web UI.
2. Select the Virtual Hardware tab.
3. Mouse over the PCI Device entry showing NVIDIA GRID vGPU and click on the (X) icon to mark the device for removal.
4. Click OK to remove the device and update the VM settings.

6.2. Modifying GPU Allocation Policy

Citrix XenServer and VMware vSphere both support the breadth first and depth-first GPU allocation policies for vGPU-enabled VMs.

Each hypervisor uses a different GPU allocation policy by default.

• Citrix XenServer uses the depth-first allocation policy
• VMware vSphere ESXi uses the breadth-first allocation policy

If the default GPU allocation policy does not meet your requirements for performance or density of vGPUs, you can change it.

6.2.1. Modifying GPU Allocation Policy on Citrix XenServer

You can modify GPU allocation policy on Citrix XenServer by using XenCenter or the xe command.

6.2.1.1. Modifying GPU Allocation Policy by Using xe

The allocation policy of a GPU group is stored in the allocation-algorithm parameter of the gpu-group object.

To change the allocation policy of a GPU group, use gpu-group-param-set:

6.2.2. Modifying GPU Allocation Policy on VMware vSphere

How to switch to a depth-first allocation scheme depends on the version of VMware vSphere that you are using.

• Supported versions earlier than 6.5: Add the following parameter to /etc/vmware/config:

  vGPU.consolidation = true
• Version 6.5: Use the vSphere Web Client.

Before using the vSphere Web Client to change the allocation scheme, ensure that the ESXi host is running and that all VMs on the host are powered off.

1. Log in to vCenter Server by using the vSphere Web Client.
2. In the navigation tree, select your ESXi host and click the Configure tab.
3. From the menu, choose Graphics and then click the Host Graphics tab.
4. On the Host Graphics tab, click Edit.

   Figure 22. Breadth-first allocation scheme setting for vGPU-enabled VMs

5. In the Edit Host Graphics Settings dialog box that opens, select these options and click OK.
   1. If not already selected, select Shared Direct.
   2. Select Group VMs on GPU until full.

   Figure 23. Host graphics settings for vGPU

   After you click OK, the default graphics type changes to Shared Direct and the allocation scheme for vGPU-enabled VMs is breadth-first.

   Figure 24. Depth-first allocation scheme setting for vGPU-enabled VMs

6. Restart the ESXi host or the Xorg service on the host.

7. Monitoring GPU Performance

NVIDIA vGPU software enables you to monitor the performance of physical GPUs and virtual GPUs from the hypervisor and from within individual guest VMs.

You can use several tools for monitoring GPU performance:

• From any supported hypervisor, and from a guest VM that is running a 64-bit edition of Windows or Linux, you can use NVIDIA System Management Interface, nvidia-smi.
• From the Citrix XenServer hypervisor, you can use Citrix XenCenter.
• From a Windows guest VM, you can use these tools:
  • Windows Performance Monitor
  • Windows Management Instrumentation (WMI)

7.1. NVIDIA System Management Interface nvidia-smi

NVIDIA System Management Interface, nvidia-smi, is a command-line tool that reports management information for NVIDIA GPUs.

The nvidia-smi tool is included in the following packages:

• NVIDIA Virtual GPU Manager package for each supported hypervisor
• NVIDIA driver package for each supported guest OS

The scope of the reported management information depends on where you run nvidia-smi from:

• From a hypervisor command shell, such as the XenServer dom0 shell or VMware ESXi host shell, nvidia-smi reports management information for NVIDIA physical GPUs and virtual GPUs present in the system.

  Note: When run from a hypervisor command shell, nvidia-smi will not list any GPU that is currently allocated for GPU pass-through.

• From a guest VM that is running Windows or Linux, nvidia-smi retrieves usage statistics for vGPUs or pass-through GPUs that are assigned to the VM.

  From a Windows guest VM, you can run nvidia-smi from a command prompt by changing to the C:\Program Files\NVIDIA Corporation\NVSMI folder and running the nvidia-smi.exe command.

7.2. Monitoring GPU Performance from a Hypervisor

You can monitor GPU performance from any supported hypervisor by using the NVIDIA System Management Interface nvidia-smi command-line utility. On Citrix XenServer platforms, you can also use Citrix XenCenter to monitor GPU performance.

Note: You cannot monitor from the hypervisor the performance of GPUs that are being used for GPU pass-through. You can monitor the performance of pass-through GPUs only from within the guest VM that is using them.

7.2.1. Using nvidia-smi to Monitor GPU Performance from a Hypervisor

You can get management information for the NVIDIA physical GPUs and virtual GPUs present in the system by running nvidia-smi from a hypervisor command shell such as the Citrix XenServer dom0 shell or the VMware ESXi host shell.

Without a subcommand, nvidia-smi provides management information for physical GPUs. To examine virtual GPUs in more detail, use nvidia-smi with the vgpu subcommand.

From the command line, you can get help information about the nvidia-smi tool and the vgpu subcommand.

7.2.1.1. Getting a Summary of all Physical GPUs in the System

To get a summary of all physical GPUs in the system, along with PCI bus IDs, power state, temperature, current memory usage, and so on, run nvidia-smi without additional arguments.

Each vGPU instance is reported in the Compute processes section, together with its physical GPU index and the amount of frame-buffer memory assigned to it.

In the example that follows, three vGPUs are running in the system: One vGPU is running on each of the physical GPUs 0, 1, and 2.

7.2.1.2. Getting a Summary of all vGPUs in the System

To get a summary of the vGPUs currently that are currently running on each physical GPU in the system, run nvidia-smi vgpu without additional arguments.

7.2.1.3. Getting vGPU Details

To get detailed information about all the vGPUs on the platform, run nvidia-smi vgpu with the –q or --query option.

To limit the information retrieved to a subset of the GPUs on the platform, use the –i or --id option to select one or more vGPUs.

7.2.1.4. Monitoring vGPU engine usage

To monitor vGPU engine usage across multiple vGPUs, run nvidia-smi vgpu with the –u or --utilization option.

For each vGPU, the usage statistics in the following table are reported once every second. The table also shows the name of the column in the command output under which each statistic is reported.

Each reported percentage is the percentage of the physical GPU’s capacity that a vGPU is using. For example, a vGPU that uses 20% of the GPU’s graphics engine’s capacity will report 20%.

To modify the reporting frequency, use the –l or --loop option.

To limit monitoring to a subset of the GPUs on the platform, use the –i or --id option to select one or more vGPUs.

7.2.1.5. Monitoring vGPU engine usage by applications

To monitor vGPU engine usage by applications across multiple vGPUs, run nvidia-smi vgpu with the –p option.

For each application on each vGPU, the usage statistics in the following table are reported once every second. Each application is identified by its process ID and process name. The table also shows the name of the column in the command output under which each statistic is reported.

Each reported percentage is the percentage of the physical GPU’s capacity used by an application running on a vGPU that resides on the physical GPU. For example, an application that uses 20% of the GPU’s graphics engine’s capacity will report 20%.

To modify the reporting frequency, use the –l or --loop option.

To limit monitoring to a subset of the GPUs on the platform, use the –i or --id option to select one or more vGPUs.

7.2.1.6. Monitoring Encoder Sessions

To monitor the encoder sessions for processes running on multiple vGPUs, run nvidia-smi vgpu with the –es or --encodersessions option.

For each encoder session, the following statistics are reported once every second:

• GPU ID
• vGPU ID
• Encoder session ID
• PID of the process in the VM that created the encoder session
• Codec type, for example, H.264 or H.265
• Encode horizontal resolution
• Encode vertical resolution
• One-second trailing average encoded FPS
• One-second trailing average encode latency in microseconds

To modify the reporting frequency, use the –l or --loop option.

To limit monitoring to a subset of the GPUs on the platform, use the –i or --id option to select one or more vGPUs.

7.2.1.7. Listing Supported vGPU Types

To list the virtual GPU types that the GPUs in the system support, run nvidia-smi vgpu with the –s or --supported option.

To limit the retrieved information to a subset of the GPUs on the platform, use the –i or --id option to select one or more vGPUs.

To view detailed information about the supported vGPU types, add the –v or --verbose option:

7.2.1.8. Listing the vGPU Types that Can Currently Be Created

To list the virtual GPU types that can currently be created on GPUs in the system, run nvidia-smi vgpu with the –c or --creatable option.

This property is a dynamic property that varies according to the vGPUs that are already running on each GPU.

To limit the retrieved information to a subset of the GPUs on the platform, use the –i or --id option to select one or more vGPUs.

To view detailed information about the vGPU types that can currently be created, add the –v or --verbose option.

7.2.2. Using Citrix XenCenter to monitor GPU performance

If you are using Citrix XenServer as your hypervisor, you can monitor GPU performance in XenCenter.

1. Click on a server’s Performance tab.
2. Right-click on the graph window, then select Actions and New Graph.
3. Provide a name for the graph.
4. In the list of available counter resources, select one or more GPU counters.

Counters are listed for each physical GPU not currently being used for GPU pass-through.

Figure 25. Using Citrix XenCenter to monitor GPU performance

7.3. Monitoring GPU Performance from a Guest VM

You can use monitoring tools within an individual guest VM to monitor the performance of vGPUs or pass-through GPUs that are assigned to the VM. The scope of these tools is limited to the guest VM within which you use them. You cannot use monitoring tools within an individual guest VM to monitor any other GPUs in the platform.

For a vGPU, only these metrics are reported in a guest VM:

• 3D/Compute
• Memory controller
• Video encoder
• Video decoder
• Frame buffer usage

Other metrics normally present in a GPU are not applicable to a vGPU and are reported as zero or N/A, depending on the tool that you are using.

7.3.1. Using nvidia-smi to Monitor GPU Performance from a Guest VM

In VMs that are running Windows and 64-bit editions of Linux, you can use the nvidia-smi command to retrieve statistics for the total usage by all applications running in the VM and usage by individual applications of the following resources:

• GPU
• Video encoder
• Video decoder
• Frame buffer

To use nvidia-smi to retrieve statistics for the total resource usage by all applications running in the VM, run the following command:

The following example shows the result of running nvidia-smi dmon from within a Windows guest VM.

Figure 26. Using nvidia-smi from a Windows guest VM to get total resource usage by all applications

To use nvidia-smi to retrieve statistics for resource usage by individual applications running in the VM, run the following command:

Figure 27. Using nvidia-smi from a Windows guest VM to get resource usage by individual applications

7.3.2. Using Windows Performance Counters to monitor GPU performance

In Windows VMs, GPU metrics are available as Windows Performance Counters through the NVIDIA GPU object.

Any application that is enabled to read performance counters can access these metrics. You can access these metrics directly through the Windows Performance Monitor application that is included with the Windows OS.

The following example shows GPU metrics in the Performance Monitor application.

Figure 28. Using Windows Performance Monitor to monitor GPU performance

On vGPUs, the following GPU performance counters read as 0 because they are not applicable to vGPUs:

• % Bus Usage
• % Cooler rate
• Core Clock MHz
• Fan Speed
• Memory Clock MHz
• PCI-E current speed to GPU Mbps
• PCI-E current width to GPU
• PCI-E downstream width to GPU
• Power Consumption mW
• Temperature C

7.3.3. Using NVWMI to monitor GPU performance

In Windows VMs, Windows Management Instrumentation (WMI) exposes GPU metrics in the ROOT\CIMV2\NV namespace through NVWMI. NVWMI is included with the NVIDIA driver package. After the driver is installed, NVWMI help information in Windows Help format is available as follows:

Any WMI-enabled application can access these metrics. The following example shows GPU metrics in the third-party application WMI Explorer, which is available for download from the from the CodePlex WMI Explorer page.

Figure 29. Using WMI Explorer to monitor GPU performance

On vGPUs, some instance properties of the following classes do not apply to vGPUs:

• Ecc
• Gpu
• PcieLink

Ecc instance properties that do not apply to vGPUs

Gpu instance properties that do not apply to vGPUs

PcieLink instance properties that do not apply to vGPUs

No instances of PcieLink are reported for vGPU.

8. XenServer vGPU Management

This chapter describes Citrix XenServer advanced vGPU management techniques using XenCenter and xe command line operations.

8.1. Management objects for GPUs

XenServer uses four underlying management objects for GPUs: physical GPUs, vGPU types, GPU groups, and vGPUs. These objects are used directly when managing vGPU by using xe, and indirectly when managing vGPU by using XenCenter.

8.1.1. pgpu - Physical GPU

A pgpu object represents a physical GPU, such as one of the multiple GPUs present on a Tesla M60 or M10 card. XenServer automatically creates pgpu objects at startup to represent each physical GPU present on the platform.

8.1.1.1. Listing the pgpu Objects Present on a Platform

To list the physical GPU objects present on a platform, use xe pgpu-list.

For example, this platform contains a Tesla P40 card with a single physical GPU and a Tesla M60 card with two physical GPUs:

8.1.1.2. Viewing Detailed Information About a pgpu Object

To view detailed information about a pgpu, use xe pgpu-param-list:

8.1.2. vgpu-type - Virtual GPU Type

A vgpu-type represents a type of virtual GPU, such as M60-0B, P40-8A, and P100-16Q. An additional, pass-through vGPU type is defined to represent a physical GPU that is directly assignable to a single guest VM.

XenServer automatically creates vgpu-type objects at startup to represent each virtual type supported by the physical GPUs present on the platform.

8.1.2.1. Listing the vgpu-type Objects Present on a Platform

To list the vgpu-type objects present on a platform, use xe vgpu-type-list.

For example, as this platform contains Tesla P100, Tesla P40, and Tesla M60 cards, the vGPU types reported are the types supported by these cards:

8.1.2.2. Viewing Detailed Information About a vgpu-type Object

To see detailed information about a vgpu-type, use xe vgpu-type-param-list:

8.1.3. gpu-group - collection of physical GPUs

A gpu-group is a collection of physical GPUs, all of the same type. XenServer automatically creates gpu-group objects at startup to represent the distinct types of physical GPU present on the platform.

8.1.3.1. Listing the gpu-group Objects Present on a Platform

To list the gpu-group objects present on a platform, use xe gpu-group-list.

For example, a system with a single Tesla P100 card, a single Tesla P40 card, and two Tesla M60 cards contains a single GPU group of type Tesla P100, a single GPU group of type Tesla P40, and two GPU groups of type Tesla M60:

8.1.3.2. Viewing Detailed Information About a gpu-group Object

To view detailed information about a gpu-group, use xe gpu-group-param-list:

8.1.4. vgpu - Virtual GPU

A vgpu object represents a virtual GPU. Unlike the other GPU management objects, vgpu objects are not created automatically by XenServer. Instead, they are created as follows:

• When a VM is configured through XenCenter or through xe to use a vGPU
• By cloning a VM that is configured to use vGPU, as explained in Cloning vGPU-Enabled VMs

8.2. Creating a vGPU using xe

Use xe vgpu-create to create a vgpu object, specifying the type of vGPU required, the GPU group it will be allocated from, and the VM it is associated with:

Creating the vgpu object for a VM does not immediately cause a virtual GPU to be created on a physical GPU. Instead, the vgpu object is created whenever its associated VM is started. For more details on how vGPUs are created at VM startup, see Controlling vGPU allocation.

Note:

The owning VM must be in the powered-off state in order for the vgpu-create command to succeed.

A vgpu object’s owning VM, associated GPU group, and vGPU type are fixed at creation and cannot be subsequently changed. To change the type of vGPU allocated to a VM, delete the existing vgpu object and create another one.

8.3. Controlling vGPU allocation

Configuring a VM to use a vGPU in XenCenter, or creating a vgpu object for a VM using xe, does not immediately cause a virtual GPU to be created; rather, the virtual GPU is created at the time the VM is next booted, using the following steps:

• The GPU group that the vgpu object is associated with is checked for a physical GPU that can host a vGPU of the required type (i.e. the vgpu object’s associated vgpu-type). Because vGPU types cannot be mixed on a single physical GPU, the new vGPU can only be created on a physical GPU that has no vGPUs resident on it, or only vGPUs of the same type, and less than the limit of vGPUs of that type that the physical GPU can support.
• If no such physical GPUs exist in the group, the vgpu creation fails and the VM startup is aborted.
• Otherwise, if more than one such physical GPU exists in the group, a physical GPU is selected according to the GPU group’s allocation policy, as described in Modifying GPU Allocation Policy.

8.3.1. Determining the Physical GPU on Which a Virtual GPU is Resident

The vgpu object’s resident-on parameter returns the UUID of the pgpu object for the physical GPU the vGPU is resident on.

To determine the physical GPU that a virtual GPU is resident on, use vgpu-param-get:

Note: If the vGPU is not currently running, the resident-on parameter is not instantiated for the vGPU, and the vgpu-param-get operation returns:

8.3.2. Controlling the vGPU types enabled on specific physical GPUs

Physical GPUs support several vGPU types, as defined in Supported GPUs and the “pass-through” type that is used to assign an entire physical GPU to a VM (see Using GPU Pass-Through on Citrix XenServer).

8.3.2.2. Controlling vGPU Types Enabled on Specific Physical GPUs by Using xe

The physical GPU’s pgpu object’s enabled-vGPU-types parameter controls the vGPU types enabled on specific physical GPUs.

To modify the pgpu object’s enabled-vGPU-types parameter , use xe pgpu-param-set:

8.3.3. Creating vGPUs on Specific Physical GPUs

To precisely control allocation of vGPUs on specific physical GPUs, create separate GPU groups for the physical GPUs you wish to allocate vGPUs on. When creating a virtual GPU, create it on the GPU group containing the physical GPU you want it to be allocated on.

For example, to create a new GPU group for the physical GPU at PCI bus ID 0000:87:00.0, follow these steps:

1. Create the new GPU group with an appropriate name: [root@xenserver ~]# xe gpu-group-create name-label="GRID P40 87:0.0" 3f870244-41da-469f-71f3-22bc6d700e71 [root@xenserver ~]#
2. Find the UUID of the physical GPU at 0000:87:0.0 that you want to assign to the new GPU group:[root@xenserver ~]# xe pgpu-list pci-id=0000:87:00.0 uuid ( RO) : f76d1c90-e443-4bfc-8f26-7959a7c85c68 vendor-name ( RO): NVIDIA Corporation device-name ( RO): GP102GL [Tesla P40] gpu-group-uuid ( RW): 134a7b71-5ceb-8066-ef1b-3b319fb2bef3 [root@xenserver ~]

   Note: The pci-id parameter passed to the pgpu-list command must be in the exact format shown, with the PCI domain fully specified (for example, 0000) and the PCI bus and devices numbers each being two digits (for example, 87:00.0).

3. Ensure that no vGPUs are currently operating on the physical GPU by checking the resident-VGPUs parameter:[root@xenserver ~]# xe pgpu-param-get uuid=f76d1c90-e443-4bfc-8f26-7959a7c85c68 param-name=resident-VGPUs [root@xenserver ~]#
4. If any vGPUs are listed, shut down the VMs associated with them.
5. Change the gpu-group-uuid parameter of the physical GPU to the UUID of the newly-created GPU group:[root@xenserver ~]# xe pgpu-param-set uuid=7c1e3cff-1429-0544-df3d-bf8a086fb70a gpu-group-uuid=585877ef-5a6c-66af-fc56-7bd525bdc2f6 [root@xenserver ~]#

Any vgpu object now created that specifies this GPU group UUID will always have its vGPUs created on the GPU at PCI bus ID 0000:05:0.0.

Note: You can add more than one physical GPU to a manually-created GPU group – for example, to represent all the GPUs attached to the same CPU socket in a multi-socket server platform - but as for automatically-created GPU groups, all the physical GPUs in the group must be of the same type.

In XenCenter, manually-created GPU groups appear in the GPU type listing in a VM’s GPU Properties. Select a GPU type within the group from which you wish the vGPU to be allocated:

Figure 32. Using a custom GPU group within XenCenter

8.4. Cloning vGPU-Enabled VMs

XenServer’s fast-clone or copying feature can be used to rapidly create new VMs from a “golden” base VM image that has been configured with NVIDIA vGPU, the NVIDIA driver, applications, and remote graphics software.

When a VM is cloned, any vGPU configuration associated with the base VM is copied to the cloned VM. Starting the cloned VM will create a vGPU instance of the same type as the original VM, from the same GPU group as the original vGPU.

8.4.1. Cloning a vGPU-enabled VM by using xe

To clone a vGPU-enabled VM from the dom0 shell, use vm-clone:

9. XenServer Performance Tuning

This chapter provides recommendations on optimizing performance for VMs running with NVIDIA vGPU on Citrix XenServer.

9.2. Using Remote Graphics

NVIDIA vGPU implements a console VGA interface that permits the VM’s graphics output to be viewed through XenCenter’s console tab. This feature allows the desktop of a vGPU-enabled VM to be visible in XenCenter before any NVIDIA graphics driver is loaded in the virtual machine, but it is intended solely as a management convenience; it only supports output of vGPU’s primary display and isn’t designed or optimized to deliver high frame rates.

To deliver high frames from multiple heads on vGPU, NVIDIA recommends that you install a high-performance remote graphics stack such as Citrix XenDesktop® with HDX 3D Pro remote graphics and, after the stack is installed, disable vGPU’s console VGA.

CAUTION:

Using Windows Remote Desktop (RDP) to access Windows 7 or Windows Server 2008 VMs running NVIDIA vGPU will cause the NVIDIA driver in the VM to be unloaded. GPU-accelerated DirectX, OpenGL, and the NVIDIA control panel will be unavailable whenever RDP is active. Installing a VNC server in the VM will allow for basic, low-performance remote access while leaving the NVIDIA driver loaded and vGPU active, but for high performance remote accesses, use an accelerated stack such as XenDesktop.

9.2.1. Disabling console VGA

The console VGA interface in vGPU is optimized to consume minimal resources, but when a system is loaded with a high number of VMs, disabling the console VGA interface entirely may yield some performance benefit.

Once you have installed an alternate means of accessing a VM (such as XenDesktop or a VNC server), its vGPU console VGA interface can be disabled by specifying disable_vnc=1 in the VM’s platform:vgpu_extra_args parameter:

The new console VGA setting takes effect the next time the VM is started or rebooted. With console VGA disabled, the XenCenter console will display the Windows boot splash screen for the VM, but nothing beyond that.

CAUTION:

If you disable console VGA before you have installed or enabled an alternate mechanism to access the VM (such as XenDesktop), you will not be able to interact with the VM once it has booted.

You can recover console VGA access by making one of the following changes:

• Removing the vgpu_extra_args key from the platform parameter
• Removing disable_vnc=1 from the vgpu_extra_args key
• Setting disable_vnc=0, for example:[root@xenserver ~]# xe vm-param-set uuid=e71afda4-53f4-3a1b-6c92-a364a7f619c2 platform:vgpu_extra_args="disable_vnc=0"

9.3. Allocation Strategies

Strategies for pinning VM CPU cores to physical cores on Non-Uniform Memory Access (NUMA) platforms and for allocating VMs to CPUs and vGPUs to physical GPUs can improve performance for VMs running with NVIDIA vGPU.

9.3.1. NUMA considerations

Server platforms typically implement multiple CPU sockets, with system memory and PCI Express expansion slots local to each CPU socket, as illustrated in Figure 34:

Figure 34. A NUMA server platform

These platforms are typically configured to operate in Non-Uniform Memory Access (NUMA) mode; physical memory is arranged sequentially in the address space, with all the memory attached to each socket appearing in a single contiguous block of addresses. The cost of accessing a range of memory from a CPU or GPU varies; memory attached to the same socket as the CPU or GPU is accessible at lower latency than memory on another CPU socket, because accesses to remote memory must additionally traverse the interconnect between CPU sockets.

To obtain best performance on a NUMA platform, NVIDIA recommends pinning VM vCPU cores to physical cores on the same CPU socket to which the physical GPU hosting the VM’s vGPU is attached. For example, using as a reference, a VM with a vGPU allocated on physical GPU 0 or 1 should have its vCPUs pinned to CPU cores on CPU socket 0. Similarly, a VM with a vGPU allocated on physical GPU 2 or 3 should have its vCPUs pinned to CPU cores on socket 1.

See Pinning VMs to a specific CPU socket and cores for guidance on pinning vCPUs, and How GPU locality is determined for guidance on determining which CPU socket a GPU is connected to. Controlling the vGPU types enabled on specific physical GPUs describes how to precisely control which physical GPU is used to host a vGPU, by creating GPU groups for specific physical GPUs.

9.3.2. Maximizing performance

To maximize performance as the number of vGPU-enabled VMs on the platform increases, NVIDIA recommends adopting a breadth-first allocation: allocate new VMs on the least-loaded CPU socket, and allocate the VM’s vGPU on an available, least-loaded, physical GPU connected via that socket.

XenServer creates GPU groups with a default allocation policy of depth-first. See Modifying GPU Allocation Policy on Citrix XenServer for details on switching the allocation policy to breadth-first.

Note: Due to vGPU’s requirement that only one type of vGPU can run on a physical GPU at any given time, not all physical GPUs may be available to host the vGPU type required by the new VM.

10. Troubleshooting

This chapter describes basic troubleshooting steps for NVIDIA vGPU on Citrix XenServer and VMware vSphere, and how to collect debug information when filing a bug report.

10.1. Known issues

Before troubleshooting or filing a bug report, review the release notes that accompany each driver release, for information about known issues with the current release, and potential workarounds.

10.2. Troubleshooting steps

If a vGPU-enabled VM fails to start, or doesn’t display any output when it does start, follow these steps to narrow down the probable cause.

10.2.1. Verifying the NVIDIA Kernel Driver Is Loaded

1. Use the command that your hypervisor provides to verify that the kernel driver is loaded:
   • On Citrix XenServer, use lsmod: [root@xenserver ~]# lsmod|grep nvidia nvidia 9604895 84 i2c_core 20294 2 nvidia,i2c_i801 [root@xenserver ~]#
   • On VMware vSphere, use vmkload_mod:[root@esxi:~] vmkload_mod -l | grep nvidia nvidia 5 8420
2. If the nvidia driver is not listed in the output, check dmesg for any load-time errors reported by the driver (see Examining NVIDIA kernel driver output).
3. On Citrix XenServer, also use the rpm -q command to verify that the NVIDIA GPU Manager package is correctly installed.rpm -q vgpu-manager-rpm-package-namevgpu-manager-rpm-package-nameThe RPM package name of the NVIDIA GPU Manager package, for example NVIDIA-vGPU-xenserver-7.0-384.155 for Citrix XenServer.

   This example verifies that the NVIDIA GPU Manager package for Citrix XenServer is correctly installed.

   [root@xenserver ~]# rpm –q NVIDIA-vGPU-xenserver-7.0-384.155 [root@xenserver ~]# If an existing NVIDIA GRID package is already installed and you don’t select the upgrade (-U) option when installing a newer GRID package, the rpm command will return many conflict errors. Preparing packages for installation... file /usr/bin/nvidia-smi from install of NVIDIA-vGPU-xenserver-7.0-384.155.x86_64 conflicts with file from package NVIDIA-vGPU-xenserver-7.0-367.137.x86_64 file /usr/lib/libnvidia-ml.so from install of NVIDIA-vGPU-xenserver-7.0-384.155.x86_64 conflicts with file from package NVIDIA-vGPU-xenserver-7.0-367.137.x86_64 ...

10.2.3. Examining NVIDIA kernel driver output

Information and debug messages from the NVIDIA kernel driver are logged in kernel logs, prefixed with NVRM or nvidia.

Run dmesg on Citrix XenServer and VMware vSphere, and check for the NVRM and nvidia prefixes:

10.2.4. Examining NVIDIA Virtual GPU Manager Messages

Information and debug messages from the NVIDIA Virtual GPU Manager are logged to the hypervisor’s log files, prefixed with vmiop.

10.2.4.1. Examining Citrix XenServer vGPU Manager Messages

For Citrix XenServer, NVIDIA Virtual GPU Manager messages are written to /var/log/messages.

Look in the /var/log/messages file for the vmiop prefix:

10.2.4.2. Examining VMware vSphere vGPU Manager Messages

For VMware vSphere, NVIDIA Virtual GPU Manager messages are written to the vmware.log file in the guest VM’s storage directory.

Look in the vmware.log file for the vmiop prefix:

10.3. Capturing configuration data for filing a bug report

When filing a bug report with NVIDIA, capture relevant configuration data from the platform exhibiting the bug in one of the following ways:

• On any supported hypervisor, run nvidia-bug-report.sh.
• On Citrix XenServer, create a XenServer server status report.

10.3.1. Capturing configuration data by running nvidia-bug-report.sh

The nvidia-bug-report.sh script captures debug information into a gzip-compressed log file on the server.

Run nvidia-bug-report.sh from the Citrix XenServer dom0 shell or the VMware ESXi host shell.

This example runs nvidia-bug-report.sh on Citrix XenServer, but the procedure is the same on VMware vSphere ESXi.

10.3.2. Capturing Configuration Data by Creating a XenServer Status Report

1. In XenCenter, from the Tools menu, choose Server Status Report.
2. Select the XenServer instance from which you want to collect a status report.
3. Select the data to include in the report.
4. To include NVIDIA vGPU debug information, select NVIDIA-logs in the Report Content Item list.
5. Generate the report.

   Figure 35. Including NVIDIA logs in a XenServer status report

A. Changing vGPU Scheduling Policy

GPUs based on the NVIDIA Maxwell™ graphic architecture implement a best effort vGPU scheduler that aims to balance performance across vGPUs. The best effort scheduler allows a vGPU to use GPU processing cycles that are not being used by other vGPUs. Under some circumstances, a VM running a graphics-intensive application may adversely affect the performance of graphics-light applications running in other VMs.

GPUs based on the NVIDIA Pascal™ architecture additionally support equal share and fixed share vGPU schedulers. These schedulers impose a limit on GPU processing cycles used by a vGPU, which prevents graphics-intensive applications running in one VM from affecting the performance of graphics-light applications running in other VMs. On GPUs based on the Pascal architecture, you can select the vGPU scheduler to use.

Note: If you use the equal share or fixed share vGPU scheduler, the frame-rate limiter (FRL) is disabled.

The GPUs that are based on the Pascal architecture are the Tesla P4, Tesla P6, Tesla P40, and Tesla P100.

A.1. vGPU Scheduling Policies

GPUs based on the Pascal architecture support equal share (default) and fixed share vGPU schedulers.

A.2. RmPVMRL Registry Key

The RmPVMRL registry key sets the scheduling policy for NVIDIA vGPUs.

Note: You can change the vGPU scheduling policy only on GPUs based on the Pascal architecture.

Contents

Examples

This example sets the vGPU scheduler to Fixed Share Scheduler.

This example sets the vGPU scheduler to Equal Share Scheduler.

A.3. Changing the vGPU Scheduling Policy for All GPUs

Note: You can change the vGPU scheduling policy only on GPUs based on the Pascal architecture.

Perform this task in your hypervisor command shell.

1. Open a command shell as the root user on your hypervisor host machine. On all supported hypervisors, you can use secure shell (SSH) for this purpose. Individual hypervisors may provide additional means for logging in. For details, refer to the documentation for your hypervisor.
2. Set the RmPVMRL registry key to the value that sets the GPU scheduling policy that you want.

   • On Citrix XenServer, add the following entry to the /etc/modprobe.d/nvidia.conf file.

     options nvidia NVreg_RegistryDwords="RmPVMRL=value"

     If the /etc/modprobe.d/nvidia.conf file does not already exist, create it.

   • On VMware vSphere, use the esxcli set command.

     # esxcli system module parameters set -m nvidia -p "NVreg_RegistryDwords=RmPVMRL=value"
   value

   The value that sets the vGPU scheduling policy that you want, for example:

   0x01Sets the vGPU scheduling policy to Equal Share Scheduler. 0x11Sets the vGPU scheduling policy to Fixed Share Scheduler.

   For all supported values, see RmPVMRL Registry Key.

3. Reboot your hypervisor host machine.

A.4. Changing the vGPU Scheduling Policy for Select GPUs

Note: You can change the vGPU scheduling policy only on GPUs based on the Pascal architecture.

Perform this task in your hypervisor command shell.

1. Open a command shell as the root user on your hypervisor host machine. On all supported hypervisors, you can use secure shell (SSH) for this purpose. Individual hypervisors may provide additional means for logging in. For details, refer to the documentation for your hypervisor.
2. Use the lspci command to obtain the PCI domain and bus/device/function (BDF) of each GPU for which you want to change the scheduling behavior.
   • On Citrix XenServer, add the -D option to display the PCI domain and the -d 10de: option to display information only for NVIDIA GPUs.# lspci -D -d 10de:
   • On VMware vSphere, pipe the output of lspci to the grep command to display information only for NVIDIA GPUs.# lspci | grep NVIDIA

   The NVIDIA GPU listed in this example has the PCI domain 0000 and BDF 86:00.0.

   0000:86:00.0 3D controller: NVIDIA Corporation GP104GL [Tesla P4] (rev a1)
3. Use the module parameter NVreg_RegistryDwordsPerDevice to set the pci and RmPVMRL registry keys for each GPU.

   • On Citrix XenServer, add the following entry to the /etc/modprobe.d/nvidia.conf file.

     options nvidia NVreg_RegistryDwordsPerDevice="pci=pci-domain:pci-bdf;RmPVMRL=value [;pci=pci-domain:pci-bdf;RmPVMRL=value...]"

     If the /etc/modprobe.d/nvidia.conf file does not already exist, create it.

   • On VMware vSphere, use the esxcli set command.

     # esxcli system module parameters set -m nvidia \ -p "NVreg_RegistryDwordsPerDevice=pci=pci-domain:pci-bdf;RmPVMRL=value\ [;pci=pci-domain:pci-bdf;RmPVMRL=value...]"

   For each GPU, provide the following information:

   pci-domainThe PCI domain of the GPU.pci-bdfThe PCI device BDF of the GPU.value

   The value that sets the vGPU scheduling policy that you want, for example:

   0x01Sets the GPU scheduling policy to Equal Share Scheduler. 0x11Sets the GPU scheduling policy to Fixed Share Scheduler.

   For all supported values, see RmPVMRL Registry Key.

   This example adds an entry to the /etc/modprobe.d/nvidia.conf file to change the scheduling behavior of a single GPU. The entry sets the vGPU scheduling policy of the GPU at PCI domain 0000 and BDF 86:00.0 to Fixed Share Scheduler.

   options nvidia NVreg_RegistryDwordsPerDevice= "pci=0000:86:00.0;RmPVMRL=0x11"
4. Reboot your hypervisor host machine.

A.5. Restoring Default vGPU Scheduler Settings

Perform this task in your hypervisor command shell.

1. Open a command shell as the root user on your hypervisor host machine. On all supported hypervisors, you can use secure shell (SSH) for this purpose. Individual hypervisors may provide additional means for logging in. For details, refer to the documentation for your hypervisor.
2. Unset the RmPVMRL registry key.

   • On Citrix XenServer, comment out the entries in the /etc/modprobe.d/nvidia.conf file that set RmPVMRL by prefixing each entry with the # character.

   • On VMware vSphere, set the module parameter to an empty string.

     # esxcli system module parameters set -m nvidia -p "module-parameter="module-parameterThe module parameter to set, which depends on whether the scheduling behavior was changed for all GPUs or select GPUs:
     • For all GPUs, set the NVreg_RegistryDwords module parameter.
     • For select GPUs, set the NVreg_RegistryDwordsPerDevice module parameter.

     For example, to restore default vGPU scheduler settings after they were changed for all GPUs, enter this command:

     # esxcli system module parameters set -m nvidia -p "NVreg_RegistryDwords="
3. Reboot your hypervisor host machine.

B. XenServer Basics

To install and configure NVIDIA vGPU software and optimize XenServer operation with vGPU, some basic operations on XenServer that are needed.

B.1. Opening a dom0 shell

Most configuration commands must be run in a command shell on XenServer’s dom0. You can open a shell on XenServer’s dom0 in any of the following ways:

• Using the console window in XenCenter
• Using a standalone secure shell (SSH) client

B.1.1. Accessing the dom0 shell through XenCenter

1. In the left pane of the XenCenter window, select the XenServer host that you want to connect to.
2. Click on the Console tab to open the XenServer’s console.
3. Press Enter to start a shell prompt.

Figure 36. Connecting to the dom0 shell by using XenCenter

B.2. Copying files to dom0

You can easily copy files to and from XenServer dom0 in any of the following ways:

• Using a Secure Copy Protocol (SCP) client
• Using a network-mounted file system

B.2.1. Copying files by using an SCP client

The SCP client to use for copying files to dom0 depends on where you are running the client from.

• If you are running the client from dom0, use the secure copy command scp.

  The scp command is part of the SSH suite of applications. It is implemented in dom0 and can be used to copy from a remote SSH-enabled server:

  [root@xenserver ~]# scp :/tmp/somefile . The authenticity of host '10.31.213.96 (10.31.213.96)' can't be established. RSA key fingerprint is 26:2d:9b:b9:bf:6c:81:70:36:76:13:02:c1:82:3d:3c. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '10.31.213.96' (RSA) to the list of known hosts. 's password: somefile 100% 532 0.5KB/s 00:00 [root@xenserver ~]#

• If you are running the client from Windows, use the pscp program.

  The pscp program is part of the PuTTY suite and can be used to copy files from a remote Windows system to XenServer:

  C:\Users\nvidia>pscp somefile :/tmp 's password: somefile | 80 kB | 80.1 kB/s | ETA: 00:00:00 | 100% C:\Users\nvidia>

B.2.2. Copying files by using a CIFS-mounted file system

You can copy files to and from a CIFS/SMB file share by mounting the share from dom0.

The following example shows how to mount a network share \\myserver.example.com\myshare at /mnt/myshare on dom0 and how to copy files to and from the share. The example assumes that the file share is part of an Active Directory domain called example.com and that user myuser has permissions to access the share.

1. Create the directory /mnt/myshare on dom0.[root@xenserver ~]# mkdir /mnt/myshare
2. Mount the network share \\myserver.example.com\myshare at /mnt/myshare on dom0.[root@xenserver ~]# mount -t cifs -o username=myuser,workgroup=example.com //myserver.example.com/myshare /mnt/myshare Password: [root@xenserver ~]#
3. When prompted for a password, enter the password for myuser in the example.com domain.
4. After the share has been mounted, copy files to and from the file share by using the cp command to copy them to and from /mnt/myshare:[root@xenserver ~]# cp /mnt/myshare/NVIDIA-vGPU-xenserver-7.0-384.155.x86_64.rpm . [root@xenserver ~]#

B.3. Determining a VM’s UUID

You can determine a virtual machine’s UUID in any of the following ways:

• Using the xe vm-list command in a dom0 shell
• Using XenCenter

B.3.1. Determining a VM’s UUID by using xe vm-list

Use the xe vm-list command to list all VMs and their associated UUIDs or to find the UUID of a specific named VM.

• To list all VMs and their associated UUIDs, use xe vm-list without any parameters:

  [root@xenserver ~]# xe vm-list uuid ( RO) : 6b5585f6-bd74-2e3e-0e11-03b9281c3ade name-label ( RW): vgx-base-image-win7-64 power-state ( RO): halted uuid ( RO) : fa3d15c7-7e88-4886-c36a-cdb23ed8e275 name-label ( RW): test-image-win7-32 power-state ( RO): halted uuid ( RO) : 501bb598-a9b3-4afc-9143-ff85635d5dc3 name-label ( RW): Control domain on host: xenserver power-state ( RO): running uuid ( RO) : 8495adf7-be9d-eee1-327f-02e4f40714fc name-label ( RW): vgx-base-image-win7-32 power-state ( RO): halted

• To find the UUID of a specific named VM, use the name-label parameter to xe vm-list:

  [root@xenserver ~]# xe vm-list name-label=test-image-win7-32 uuid ( RO) : fa3d15c7-7e88-4886-c36a-cdb23ed8e275 name-label ( RW): test-image-win7-32 power-state ( RO): halted

B.3.2. Determining a VM’s UUID by using XenCenter

1. In the left pane of the XenCenter window, select the VM whose UUID you want to determine.
2. In the right pane of the XenCenter window, click the General tab.

The UUID is listed in the VM’s General Properties.

Figure 37. Using XenCenter to determine a VM's UUID

B.4. Using more than two vCPUs with Windows client VMs

Windows client operating systems support a maximum of two CPU sockets. When allocating vCPUs to virtual sockets within a guest VM, XenServer defaults to allocating one vCPU per socket. Any more than two vCPUs allocated to the VM won’t be recognized by the Windows client OS.

To ensure that all allocated vCPUs are recognized, set platform:cores-per-socket to the number of vCPUs that are allocated to the VM:

vm-uuid is the VM’s UUID, which you can obtain as explained in Determining a VM’s UUID.

B.5. Pinning VMs to a specific CPU socket and cores

1. Use xe host-cpu-info to determine the number of CPU sockets and logical CPU cores in the server platform. In this example the server implements 32 logical CPU cores across two sockets: [root@xenserver ~]# xe host-cpu-info cpu_count : 32 socket_count: 2 vendor: GenuineIntel speed: 2600.064 modelname: Intel(R) Xeon(R) CPU E5-2670 0 @ 2.60GHz family: 6 model: 45 stepping: 7 flags: fpu de tsc msr pae mce cx8 apic sep mtrr mca cmov pat clflush acpi mmx fxsr sse sse2 ss ht nx constant_tsc nonstop_tsc aperfmperf pni pclmulqdq vmx est ssse3 sse4_1 sse4_2 x2apic popcnt aes hypervisor ida arat tpr_shadow vnmi flexpriority ept vpid features: 17bee3ff-bfebfbff-00000001-2c100800 features_after_reboot: 17bee3ff-bfebfbff-00000001-2c100800 physical_features: 17bee3ff-bfebfbff-00000001-2c100800 maskable: full
2. Set VCPUs-params:mask to pin a VM’s vCPUs to a specific socket or to specific cores within a socket. This setting persists over VM reboots and shutdowns. In a dual socket platform with 32 total cores, cores 0-15 are on socket 0, and cores 16-31 are on socket 1. In the examples that follow, vm-uuid is the VM’s UUID, which you can obtain as explained in Determining a VM’s UUID.
   • To restrict a VM to only run on socket 0, set the mask to specify cores 0-15:[root@xenserver ~]# xe vm-param-set uuid=vm-uuid VCPUs-params:mask=0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
   • To restrict a VM to only run on socket 1, set the mask to specify cores 16-31:[root@xenserver ~]# xe vm-param-set uuid=vm-uuid VCPUs-params:mask=16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
   • To pin vCPUs to specific cores within a socket, set the mask to specify the cores directly:[root@xenserver ~]# xe vm-param-set uuid=vm-uuid VCPUs-params:mask=16,17,18,19
3. Use xl vcpu-list to list the current assignment of vCPUs to physical CPUs:[root@xenserver ~]# xl vcpu-list Name ID VCPU CPU State Time(s) CPU Affinity Domain-0 0 0 25 -b- 9188.4 any cpu Domain-0 0 1 19 r-- 8908.4 any cpu Domain-0 0 2 30 -b- 6815.1 any cpu Domain-0 0 3 17 -b- 4881.4 any cpu Domain-0 0 4 22 -b- 4956.9 any cpu Domain-0 0 5 20 -b- 4319.2 any cpu Domain-0 0 6 28 -b- 5720.0 any cpu Domain-0 0 7 26 -b- 5736.0 any cpu test-image-win7-32 34 0 9 -b- 17.0 4-15 test-image-win7-32 34 1 4 -b- 13.7 4-15

B.6. Changing dom0 vCPU Default configuration

By default, dom0 vCPUs are configured as follows:

• The number of vCPUs assigned to dom0 is 8.
• The dom0 shell’s vCPUs are unpinned and able to run on any physical CPU in the system.

B.6.1. Changing the number of dom0 vCPUs

The default number of vCPUs assigned to dom0 is 8.

1. Modify the dom0_max_vcpus parameter in the Xen boot line.

   For example:

   [root@xenserver ~]# /opt/xensource/libexec/xen-cmdline --set-xen dom0_max_vcpus=4
2. After applying this setting, reboot the system for the setting to take effect by doing one of the following:
   • Run the following command:shutdown –r
   • Reboot the system from XenCenter.

B.6.2. Pinning dom0 vCPUs

By default, dom0’s vCPUs are unpinned, and able to run on any physical CPU in the system.

1. To pin dom0 vCPUs to specific physical CPUs, use xl vcpu-pin.

   For example, to pin dom0’s vCPU 0 to physical CPU 18, use the following command:

   [root@xenserver ~]# xl vcpu-pin Domain-0 0 18 CPU pinnings applied this way take effect immediately but do not persist over reboots.
2. To make settings persistent, add xl vcpu-pin commands into /etc/rc.local.

   For example:

   xl vcpu-pin 0 0 0-15 xl vcpu-pin 0 1 0-15 xl vcpu-pin 0 2 0-15 xl vcpu-pin 0 3 0-15 xl vcpu-pin 0 4 16-31 xl vcpu-pin 0 5 16-31 xl vcpu-pin 0 6 16-31 xl vcpu-pin 0 7 16-31

B.7. How GPU locality is determined

As noted in NUMA considerations, current multi-socket servers typically implement PCIe expansion slots local to each CPU socket and it is advantageous to pin VMs to the same socket that their associated physical GPU is connected to.

For current Intel platforms, CPU socket 0 typically has its PCIe root ports located on bus 0, so any GPU below a root port located on bus 0 is connected to socket 0. CPU socket 1 has its root ports on a higher bus number, typically bus 0x20 or bus 0x80 depending on the specific server platform.

1 A-series NVIDIA vGPUs support a single display at low resolution to be used as the console display in remote application environments such as RDSH and XenApp. The maximum resolution for the A-series NVIDIA vGPUs applies only to the console display. The maximum resolution of each RDSH or XenApp session is not restricted by the maximum resolution of the vGPU.