Features/XenPvopsDom0

Feature Name

Summary

Dom0 support for pvops-based kernel to support hosting of Xen guests which has been lacking since Fedora 8.

Currently Fedora releases (9, 10, 11, 12, 13) contain Xen hypervisor and tools, but Xen dom0 (host) capable kernel is missing.

Owner

• Name: None

Previously involved: EduardoHabkost, MarkMcLoughlin, Stephen Tweedie, Chris Wright, Juan Quintela, Markus Armbruster, Glauber Costa, DanielBerrange, ...

Current status

• Last updated: 2010-08-16
• Percentage of completion: 0%
• Targeted release: F14
• Dom0 status: awaiting upstream kernel support
• Background:

Upstream status and build instructions, XenParavirtOps on xenwiki,

Upstream patches (git branches):

• xen/stable-2.6.32.x - Upstream long-term maintained stable branch with dom0 support.

• News: FWN #169, FWN #152, FWN #137
• Status updates: See upstream XenParavirtOps wiki page for status updates and progress of Xen pv_ops dom0 kernel.
• Xen pv_ops dom0 kernel is the default kernel in Xen hypervisor 4.0 release.
• M A Young has built unofficial pv_ops dom0 kernel RPMs for testing, available from his directory, or from new directory. For feedback or questions about these kernels you should email to fedora-virt or fedora-xen mailinglists.
• Note that the latest pvops dom0 kernels require Xen hypervisor 4.0.1!! src.rpm for fedora available from: http://pasik.reaktio.net/fedora/xen-4.0.1-0.2.fc13.src.rpm or from: http://koji.fedoraproject.org/koji/taskinfo?taskID=2426589 .
• If you want to build your own custom dom0 kernel, see the upstream XenDom0Kernels wiki page

Detailed Description

See Features/XenPvops for a rationale. This feature just continues the paravirt_ops Xen effort to bring it back to feature parity with Fedora 8 Xen.

Scope

Work items:

• Implement Dom0 support in upstream kernel (JeremyFitzhardinge)
• Allow the hypervisor to boot bzImage kernels (see this patch included since xen-3.3.1-3.fc11)
• Make 'new-kernel-pkg' aware of HYPERVISOR setting in /etc/sysconfig/xen
• Wait for that upstream kernel version to be pulled into Fedora

How To Test

• Install a Fedora host/Dom0 system
• Turn on Xen Hypervisor by setting 'HYPERVISOR=/boot/xen-4.0.gz' in /etc/sysconfig/kernel and running some tool (TBD)
• Turn on Xen Userspace by running 'chkconfig xend on'
• Reboot
• Observe presence of Xen via /sys/hypervisor/
• Run 'xm list' and observe Domain-0
• Use virt-install to deploy a Fedora 11/12/13 paravirt guest
• Use virt-install to deploy a Fedora 11/12/13 fullyvirt guest
• Use 'virsh' to save & restore a PV guest and HVM guest
• Balloon down memory of a guest with virsh.

User Experience

• Stock Fedora kernel supports Xen dom0
• The Xen kernel does not lag behind the Fedora kernel
• All features and hardware supported on baremetal also works on Xen Dom0
• Can enable/disable use of HV via a /etc/sysconfig setting

Dependencies

• Update to 'new-kernel-pkg' to know how to install HV

Contingency Plan

If Dom0 support is not ready, continue the status quo of only shipping with DomU support.

Comments and Discussion

• See Talk:Features/XenPvopsDom0