Linux 5.8 To Allow For Faster Xen 9pfs Performance

The Linux kernel's 9P protocol support with the in-development Linux 5.8 kernel will see the potential for faster performance with its Xen transport code.

The Xen transport for 9pfs provides simple network file-system/transfer support between Xen domains. The sole change for the kernel's 9P code in Linux 5.8 is one for the Xen transport code to increase the size of the XEN_9PFS_RING_ORDER.

The change of the ring order size for Xen 9pfs was made by a Xilinx engineer to the maximum value of 9 for performance reasons. Though with not all back-ends supporting order 9, special handling was done for supporting the maximum ring order possible. No performance numbers were shared as part of the commit besides acknowledging it should help with the Xen 9pfs transport performance.