• Contact: port-xen

Abstract: The blktap2 method provides a userland daemon to provide access to on disk files, arbitrated by the kernel. The NetBSD kernel lacks this support and currently disables blktap in xentools.

Deliverables:

• blktap2 driver for /dev/blktapX
• Tool support to be enabled in xentools
• Enable access to various file formats (Qcow, VHD etc) , via the [ tap: ] disk specification.

Implementation:

The driver interacts with some areas of the kernel that are different from linux - eg: inter-domain page mapping, interdomain signalling. This may make it more challenging than a simple driver, especially with test/debug/performance risk.

Note: There's opportunity to compare notes with the FUSE/rump implementations.

See http://wiki.xenproject.org/wiki/Blktap and http://xenbits.xensource.com/hg/xen-unstable.hg/file/tip/tools/blktap2/README