Xen paravirtual block device backend (xen-blkback)
The host-side counterpart to Xen's virtual disk driver: it runs inside a Xen dom0 or storage driver domain and serves block I/O to paravirtualised guest VMs, letting them see host disks, LVM volumes, or image files as their own block devices. It is the standard backend behind Xen disk configurations on Linux hypervisor hosts.
recommendation
Worth keeping but documenting its niche because it is the in-kernel server side of Xen's paravirtualised disk protocol, used by dom0 and driver domains to expose host storage to Xen guests. Upstream maintenance is still happening (a 2024 patch landed) and the option remains shipped in current kernels, but its audience is narrow — Xen hosts rather than general Linux servers — and there is no drop-in in-kernel replacement, so it should stay with a note about its specifically-Xen role.
repository signals
sources
- lore.kernel.org
Recent upstream maintenance exists for xen-blkback; lore history shows a 2024 xen/blkback patch rather than abandonment.
- xenbits.xenproject.org
Current Xen documentation still describes backend domains and Xen disk backend implementations, indicating ongoing real-world Xen block-backend deployments.
- cateee.net
CONFIG_XEN_BLKDEV_BACKEND remains present through current kernel series/HEAD, so the driver is still shipped and configurable upstream.
codex reasoning notes (technical)
Virtual backend, not physical hardware, so 'sold new' is not applicable and is marked false. Recommendation is keep-annotate: active lore evidence shows recent maintenance, while deployment is a niche Xen dom0/driver-domain role rather than broad new hardware deployment. No clear same-role upstream replacement driver surfaced; Xen can also use other backend implementations/toolstack options, but not as a direct in-kernel replacement for xen-blkback. URLs obtained via lore_file_timeline (lore URL) and web search plus open on Xen Project docs and LKDDb.