• Contact: port-xen
• Duration estimate: 48 hours

Abstract: This is the first step towards PVH mode. This is relevant only for DomU. Speeds up amd64 - PV on amd64 has sub-optimal TLB and syscall overhead due to privilege level sharing between kernel and userland.

Deliverables:

• operational PV drivers (netif.h, blkif.h) on HVM mode.

Implementation:

• Xen needs to be detected at boottime.
• The shared page and hypercall interface need to be setup.
• xenbus(4) attachment during bootime configuration.

Scope (Timelines):

This project involves intrusive kernel configuration changes, since NetBSD currently has separate native (GENERIC) and xen (XEN3_DOMU) kernels. A "hybrid" build is required to bring in the PV drivers and xen infrastructure support such as xenbus(4).

Once the hypercall page is up however, progress should be faster.

See:

http://wiki.xenproject.org/wiki/XenParavirtOps and http://wiki.xenproject.org/wiki/PV_on_HVM