Archived/Xen Project Release Features 4.0 to 4.3

From Xen

Legend:

  • : Feature
  • : Partial
  • : Removed
  • For definitions of experimental, preview, supported and deprecated see here

Overview

Xen 4.0 Xen 4.1 Xen 4.2 Xen 4.3
Initial Release 7 April 2010 25 March 2011 17 Sept 2012 9 July 2013
Supported until ???[ 21 ] ???[ 21 ] ???[ 21 ] Jan 2015
Security support until ???[ 21 ] ???[ 21 ] Sept 2015 July 2016
Feature List FL 4.2 FL 4.3
Release Notes RN 4.0 RN 4.1 RN 4.2 RN 4.3
Supported Mainline Architectures for the hypervisor (Host)
IA-A32 removed
X86-64
Itanium (ia64) deprecated in this release deprecated removed
ARM v7 + Virtualization Extensions preview [ 6 ]
ARM v8 preview [ 6 ]
Guest Types
For X86 Architectures
Paravirtualised
Traditional Xen Project PV guest
HVM Guest [ 1 ]
Fully virtualised guest using hardware virtualisation extensions
PV-on-HVM Guest [ 1 ]
Fully virtualised guest using PV extensions/drivers for improved performance
For ARM Architectures
ARM Guest
Optimal combination of full virtualization and PV extensions
preview [ 6 ]


Limits

Xen 4.0 Xen 4.1 Xen 4.2 Xen 4.3
Host Limits
For X86 Architectures
Physical CPUs 128 [ 0 ] >255 4095 4095
Physical RAM 1TB 5TB 5TB 16TB
For ARM Architectures
Physical CPUs 8
Physical RAM 16GB
Guest Limits
X86 PV Guest Limits
Virtual CPUs 128 >255 512 512
Virtual RAM 512GB 512GB 512GB 512GB
X86 HVM Guest Limits
Virtual CPUs 128 128 128 128
Virtual RAM 1TB 1TB 1TB 1TB
ARM Guest Limits
Virtual CPUs 8
Virtual RAM 16GB
Number of event channels
Event Channels 1024/4096 1024/4096 1024/4096 1024/4096



Toolstack and Tools

Xen 4.0 Xen 4.1 Xen 4.2 Xen 4.3
Toolstack
Built-in
xend / xm deprecated in this release deprecated
XL initial implementation preview release
Qemu based disk backend (qdisk) for XL
[ 5 ] [ 5 ] [ 5 ]
XL Open vSwitch integration preview
3rd Party
libvirt driver for XL
Tooling
gdbsx
debugger to debug ELF guests
vPMU
Virtual Performance Management Unit for HVM guests
[ 4 ] [ 4 ] [ 4 ] [ 4 ]
Serial console Add EHCI debug support
xentrace
performance analysis


Features

Xen 4.0 Xen 4.1 Xen 4.2 Xen 4.3
Advanced Memory Management
Memory Ballooning
Memory Sharing
allow sharing of identical pages between HVM guests
preview preview preview [ 3 ] preview [ 3 ]
Memory Paging
allow pages belonging to HVM guests to be paged to disk
preview preview preview [ 3 ] preview [ 3 ]
TMEM - Transcendent Memory experimental [ 2 ] experimental [ 2 ] experimental [ 2 ] experimental [ 2 ]
Resource Management
Cpupool
advanced partitioning
Credit 2 Scheduler
designed for latency-sensitive workloads and very large systems.
prototype prototype experimental
NUMA scheduler affinity
Scalability
1GB/2MB super page support
Deliver events to PVHVM guests using Xen event channels
Fair locks (ticket-locks)
High Availability and Fault Tolerance
Live Migration, Save & Restore
Remus Fault Tolerance
X86 vMCE
Forward Machine Check Exceptions to Appropriate guests
Network and Storage
Blktap2
Online resize of virtual disks
Security (also see this presentation or this document)
Driver Domains
Device Model Stub Domains
Virtual Machine Introspection (Memaccess and VM Event APIs)
enabling integration of 3rd party security solutions into Xen virtualized environments
XSM & FLASK
mandatory access control policy providing fine-grained controls over Xen domains, similar to SELinux
XSM & FLASK support for IS_PRIV
vTPM Support

updates and new functionality


Interoperability / Hardware Support

Xen 4.0 Xen 4.1 Xen 4.2 Xen 4.3
X86
X86 Nested Virtualisation
Running a hypervisor inside an HVM guest
experimental experimental
HVM PXE Stack (x86) gPXE iPXE iPXE iPXE
Physical CPU Hotplug
Physical Memory Hotplug
Support for PV kernels in bzImage format
PCI Passthrough [ 12 ]
X86 Advanced Vector eXtension (AVX) [ 4 ]


Device Models and Virtual Firmware

Xen 4.0 Xen 4.1 Xen 4.2 Xen 4.3
Device Models and Virtual Firmware for HVM guests
For X86 Architectures
Traditional Device Model
Device emulator based on Xen fork of Qemu
Qemu Upstream Device Model
Device emulator based on upstream Qemu
preview default, unless stubdomains are used
ROMBIOS
BIOS used with traditional device model only
SeaBIOS
BIOS used with upstream qemu device model and XL only
OVMF/Tianocore
UEFI Firmware used with upstream qemu device model and XL only
experimental [ 4 ] experimental [ 4 ]
PV Bootloader support
For X86 Architectures
PyGrub support for GRUB 2
PyGrub support for /boot on ext4
pvnetboot support
Bootloader supporting network boot of PV guests


Notes

[ 0 ] Compile time limit, can be increased
[ 1 ] Requires hardware virtualisation support
[ 2 ] Disabled by default (enable with hypervisor command line option). Not supported in production and doesn't have full security support
[ 3 ] Preview, due to limited tools support. Hypervisor side in good shape
[ 4 ] Disabled by default (enable with hypervisor command line option)
[ 5 ] Used as a fallback if blkback and/or blktap2 are not available
[ 6 ] See Xen ARM with Virtualization Extensions; basic functionality implemented; lack of real hardware to validate against
[ 12 ] Not yet supported on ARM; for a more detailed update on what is supported on ARM see here
[ 21 ] Dates for historical releases have not be researched.