VMware vSockets Release Notes

Contents:

• About VMware vSockets
• Compatibility Notice
• Changes and New Features
• Known Issues and Workarounds

About VMware vSockets

The vSockets programming interfaces are essentially unchanged in vSphere 7.0.

vSockets API. First introduced in VMware Workstation 6.5 and ported to ESX/ESXi 4.0, VMCI Sockets made 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.
• VMCI in vSphere 7.0 supports up to 64-bit physical page number (PPN64). This support does not affect calls in vSockets library nor the vSockets documentation. The support simply enables PPN64 capable guest VMCI drivers to pass down 64-bit physical page numbers to the device, such as with VMs with large amounts (many TBs) of memory.
• 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.
• Paravirtual remote direct memory access (PVRDMA) is supported as of vSphere 6.5, in certain configurations described in the vSphere Networking guide. PVRDMA is implemented as a paravirtualized NIC that implements RDMA between virtual machines calling the OFED Verbs API. For information about the OFED Verbs API for PVRDMA, see KB 2147694.