VMware vSockets Release Notes

Release date: 17 APR 2018 | ESXi build 8169922
For vSphere 6.7 GA. Last document update: 17 APR 2018
Check for additions and updates to these release notes.

Contents:

 

About VMware vSockets

The vSockets programming interfaces are essentially unchanged in vSphere 6.7.

vSockets API. First introduced in VMware Workstation 6.5 and ported to ESX/ESXi 4.0, VMCI Sockets was a convenience API for the virtual machine communications interface. It provided fast communication between guest virtual machines and their host, with minimal IP-socket code modifications, In ESXi 6.0 the name was changed to vSockets, reflecting non-use of the VMCI device.

Compatibility Notice

Support continues for host to guest communications. Guest to guest communication (VM to VM) was deprecated in vSphere 5.0 and Workstation 8.0, Inter-guest communication was removed in vSphere 5.1 and later.

Changes and New Features

  • Recent Linux kernel versions include the VMCI driver.
  • In the vSphere 6.0 release, the programming guide was renamed vSockets.

  • In the vSphere 5.1 release, the VMCI layer was circumvented, and guest to guest vSockets were removed.
  • In ESX/ESXi 4.0, when vSockets was first made available for vSphere, both datagram and stream sockets were supported.
  • In Workstation 7.0, stream sockets were supported for Linux hosts, Linux guests, and Windows guests, but only datagram sockets were supported for Windows hosts.

Known Issues and Workarounds

  • The VMCI driver is not included in-box in any release of Microsoft Windows. When users power on a Windows virtual machine, the device manager shows a missing driver for the VMCI device until VMware Tools is installed. For details, see Windows device manager shows yellow bang for VMCI device.

Note About the PVRDMA Verbs API

  • VMware vSphere 6.5 and later support paravirtual remote direct memory access (PVRDMA) in specific configurations as described in the vSphere Networking guide. PVRDMA is implemented as a paravirtualized NIC that supports RDMA between virtual machines calling the OFED Verbs API. However programs cannot call the rdma_create_ep API from guest userspace. When it works, this API facilitates connection of RDMA queue pairs between peers, but userspace programs calling this API may encounter work completion failures when virtual machines communicate over the underlying physical host channel adapter. There is no known workaround, except to use a different RDMA connection management API.