Xen 3.4 News

[Christoph Egger <Christoph_Egger%gmx.de@localhost>]

Hi,

XenSource announced the feature freeze for Xen 3.4
to happen by the end of this month. The actual
Xen 3.4 release will happen in April.


Xen 3.4 contains compared to prior major releases
just a few new features and consists mostly of
bugfixes and performance improvements.


Populate-on-Demand is a new feature which allocates
physical memory for the guest on demand. It works
like lazy memory allocation. It also allows memory
over-committing for the guest. Interesting question
is what happens with the guest in OOM case.
This feature is transparent to Dom0/DomU. No adaptions
necessary to use it.

Improved Microcode-Patch support: The hypercall
has been introduced in Xen 3.1 with support for
Intel-CPUs only. In Xen 3.4, this has been improved
to support a) newer Intel-CPUs and b) AMD-CPUs
having cpuid family >= 0x10.
The hypercall didn't change and has the same
semantic as for Xen 3.1.
To use this feature, Dom0 support is required.
Note, the improvements have been backported
to Xen 3.3 and will also be part of Xen 3.3.2.

IOMMU support got stability and performance
improvements.
This feature is transparent and no adaption
is necessary. However, the Dom0/DomU can use
'domain isolation' on PCI hardware by
(un)registering it via the
'PHYSDEVOP_manage_pci_add'/'PHYSDEVOP_manage_pci_remove'
hypercalls.

ACPI S3 host support: Several bugfixes, most
of them have been backported and will be part
of Xen 3.3.2.

CPU offline/hotplug: Xen 3.4 can offline
physical CPUs on CPU-core granularity.
CPU hotplugging works on CPU granularity.
It's meant as an recover-action for the case
of machine-check errors. This feature
requires Dom0 support to utilize it.
This feature has been almost tested
on Intel-CPUs only.

Christoph