vSphere DirectPath I/O allows a guest operating system on a virtual machine to directly access physical PCI and PCIe devices connected to a host. This action gives you direct access to devices such as high-performance graphics or sound cards. You can connect each virtual machine to up to six PCI devices.
You configure PCI devices on the host to make them available for passthrough to a virtual machine. See the vSphere Networking documentation. However, PCI passthroughs should not be enabled for ESXi hosts that are configured to boot from USB devices.
When PCI vSphere DirectPath I/O devices are available to a virtual machine, you cannot suspend, migrate with vMotion, or take or restore Snapshots of such virtual machines.
To use DirectPath, verify that the host has Intel Virtualization Technology for Directed I/O (VT-d) or AMD I/O Virtualization Technology (IOMMU) enabled in the BIOS.
Verify that the PCI devices are connected to the host and marked as available for passthrough. However, if your ESXi host is configured to boot from a USB device, you should disable the USB controller for passthrough. VMware does not support USB controller passthrough for ESXi hosts that boot from USB devices or SD cards connected through USB channels. For more information, see http://kb.vmware.com/kb/2068645.
Verify that the virtual machine is compatible with ESXi 4.x and later.
- Right-click a virtual machine in the inventory and select Edit Settings.
- On the Virtual Hardware tab, select PCI Device from the New Device drop-down menu, and click Add.
- Expand New PCI device and select the passthrough device to connect to the virtual machine from the drop-down list and click Next.
- Click OK.