What is VMDirectPath IO and GPU passthru

One of the more interesting announcements that I believe flew under the radar was the joint VMware-NVIDIA initiative to bring virtual graphics processing unit technology (vGPU) to VMware’s vSphere and the VMware cloud on AWS so it’s really a good time to understand GPU passthrough concept.

Before we start, let’s get to know CPU vs GPU:

CPU is good at handling multiple tasks but a GPU can handle a few specific tasks very fast.

CPU is good for serial processing and has low latency while GPU is good at parallel processing and hence high throughput. In marvel comic terms, CPU is like Antman, GPU is a hulk – incredible hulk!  

okay, what is this thing "GPU passthrough" :

It is a technology that allows you to directly present an internal PCI GPU to a virtual machine. The device acts as if it were directly driven by the VM, and the VM detects the PCI device as if it were physically connected. VMware calls this operation as VMDirectPath I/O.

So why do we need such stuff:

To execute workloads with more computer power, simply for faster time to results.

Who uses all these crazy things:

Gamers - for smooth graphics,

Data scientists, Artificial Intelligence, Machine / Deep learning engineers to compute more data in a faster manner.

Interesting isn't it? and let’s see how do we enable it:

To Enable the Host for GPU Passthrough:

1. Select the Configuration tab on the host, and click Advanced Setting. (If the host has devices enabled for passthrough, these devices will be listed here.)

2. To configure passthrough for the GPU, click Configure Passthrough.

3. In the Mark Devices for Passthrough window, check the box that corresponds to the GPU adapter installed in the host.

4. Click OK. The GPU should now be listed now in the Window on the Advanced settings page.

Note: If the device has an orange arrow displayed on the icon, the host needs to be rebooted before passthrough will function. If the device icon is green, passthrough is enabled.

To Enable the Virtual Machine for GPU Passthrough:

1.Right-click the virtual machine and select Edit Settings

2. Add a new device by selecting PCI Device from the list, and click Next.

3. Select the GPU as the passthrough device to connect to the virtual machine from the drop-down list, and click Next.

4. Click Finish

5. Download and install the drivers according to the Virtual Machine's OS.

6. Reboot the virtual machine.

Quick links:

Blog link to explore more about the topic - https://blogs.vmware.com/vsphere/2019/03/exploring-the-gpu-architecture-and-why-we-need-it.html