Broadcom Working On VMware Zero-Copy Buffer Sharing Between VMs And Hypervisor

Interesting feature work for VMware virtualization on Linux now being pursued by Broadcom is to support zero-copy buffer sharing between the VM(s) and host hypervisor, which would equate to an efficiency and performance win.

Posted to the Linux kernel mailing list this week were patches by Broadcom engineer Rishi Chhibber for establishing the "vmw_zerocopy_driver"that will allow guest user-space applications to share pinned memory buffers with a VMware hypervisor peer using the VMCI datagram interface in a zero-copy manner. Via this driver allows avoiding an intermediate copy between the guest VM and the hypervisor.

Details on the Broadcom plans around this zero-copy buffer sharing are still light for now but it will be interesting to see how far it's taken as avoiding the intermediate copies should provide for a nice efficiency win. But as we have seen from other zero-copy sharing bits in the Linux kernel in the past, various security gotchas have also arisen. Those wanting to see this new driver in its current patch form, enabled via the "VMW_ZC" Kconfig option, can see the patches on the kernel mailing list.