You can create OpenStack instances using DirectPath I/O and Single Root I/O Virtualization (SR-IOV) passthrough devices.


This feature is offered in VMware Integrated OpenStack Carrier Edition only. For more information, see VMware Integrated OpenStack Licensing.

Passthrough associates a physical device with a virtual machine, reducing the latency caused by virtualization. The following table shows how passthrough is implemented in VMware Integrated OpenStack.

Table 1. Key Passthrough Components and Roles



Nova compute

  • Collects the list of SR-IOV devices and updates the list of PCI device specifications.

  • Embeds the host object ID in device specifications.

Nova PCI manager

  • Creates and maintains a device pool with address, vendor ID, product ID, and host ID.

  • Allocates and deallocates PCI devices to instances based on PCI requests.

Nova scheduler

  • Schedules instance placement on hosts that match the PCI requests


  • Manages hosts in a dedicated compute cluster with NICs and hosts enabled for SR-IOV.


    DRS rules do not apply to devices enabled for SR-IOV. Place SR-IOV hosts in a separate compute cluster.