Xen 4.7 RC test instructions: Difference between revisions

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For the expressions/examples below, set the following bash/sh/... variable to the release candidate number (e.g. one of <code>rc1</code>, <code>rc2</code>, ... )
For the expressions/examples below, set the following bash/sh/... variable to the release candidate number (e.g. one of <code>rc1</code>, <code>rc2</code>, ... )
RC="<release candidate number>"
RC="<release candidate number>" # rc1, rc2 ...


=== From xen.git ===
=== From xen.git ===
Line 40: Line 40:


== RC1 ==
== RC1 ==
* [http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg00346.html XSM denials with 4.7.0 RC1]
* [http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg00346.html XSM denials with 4.7.0 RC1] - fixed in RC2
* [http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg00225.html Regression in Xen 4.7-rc1 - can't boot HVM guests with more than 64 vCPUS] (this is caused by a [http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg00379.html bug in the Linux kernel], not a bug in Xen)
* [http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg00225.html Regression in Xen 4.7-rc1 - can't boot HVM guests with more than 64 vCPUS] (this is caused by a [http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg00379.html bug in the Linux kernel], not a bug in Xen)


Line 47: Line 47:
== General ==
== General ==
* Remove any old versions of Xen toolstack and userspace binaries (including <code>qemu</code>).
* Remove any old versions of Xen toolstack and userspace binaries (including <code>qemu</code>).
* Remove any udev files under /etc because Xen 4.7 doesn't use those anymore.
* Remove any Xen-related udev files under /etc because Xen 4.7 doesn't use those anymore.
* Download and install the most recent Xen 4.7 RC, as described above. Make sure to check the <code>README</code> and <code>INSTALL</code> for changes in required development libraries and procedures. Some particular things to note:
* Download and install the most recent Xen 4.7 RC, as described above. Make sure to check the <code>README</code> and <code>INSTALL</code> for changes in required development libraries and procedures. Some particular things to note:


Line 53: Line 53:


=== USB Support for xl ===
=== USB Support for xl ===
xl introduces PVUSB support as well as the following commands:
{{TODOLeft|
* This section was not written by the author of the relevant features. Thus there may be inaccuracies
* Someone needs to go through [[Xen_USB_Passthrough#PVUSB|PVUSB]] and [[Xen_USB_Passthrough#PVUSB_in_xl.2Flibxl|PVUSB in xl]] and update it.
* Any limitations need to be documented (e.g. are there any bits and pieces pending in QEMU - is "qusb" expected to work or not yet)?
}}

[[xl]] introduces PVUSB support as well as the following [http://xenbits.xen.org/docs/4.6-testing/man/xl.1.html#PCI-PASS-THROUGH commands]:
<code>
<code>
usbctrl-attach
usbctrl-attach
Line 72: Line 66:
usbdev=[ "USB_SPEC_STRING", "USB_SPEC_STRING", ... ]
usbdev=[ "USB_SPEC_STRING", "USB_SPEC_STRING", ... ]
</code>
</code>
as outlined in the [http://xenbits.xen.org/docs/unstable/man/xl.cfg.5.html xl.cfg(5)] man page.
as outlined in the [http://xenbits.xen.org/docs/unstable/man/xl.cfg.5.html xl.cfg(5)] man page. For an overview, see [[Xen USB Passthrough]].


=== RTDS scheduler improvements ===
=== RTDS scheduler improvements ===
Line 78: Line 72:
The RTDS scheduler was improved in the following way
The RTDS scheduler was improved in the following way
* The RTDS scheduler has been changed from a quantum-driven model to an event-driven model, which will not invoke the scheduler unnecessarily: if you use this scheduler, you may want to test your workload using the RC and check whether there are any unexpected side effects
* The RTDS scheduler has been changed from a quantum-driven model to an event-driven model, which will not invoke the scheduler unnecessarily: if you use this scheduler, you may want to test your workload using the RC and check whether there are any unexpected side effects
* Support to get/set per-VCPU parameters have been added to the RTDS toolstack: see [http://xenbits.xen.org/docs/unstable/man/xl.1.html#DOMAIN-SUBCOMMANDS search for sched-rtds]
* Support to get/set RTDS scheduling parameters on a per-VCPU basis has been added to libxl and xl
** The <code>-v VCPUID/all, --vcpuid=VCPUID/all</code> options have been added


So, for instance:
=== <code>-f</code> option for <code>xl vcpu-pin</code> ===
* to see the scheduling parameters of all VCPUs of a VM use <code>-v all</code>
In order to be able to undo a vcpu pin override in case of a kernel driver error add a flag "-f" to the "xl vcpu-pin" command forcing the hypervisor to undo the override.


xl sched-rtds -d vm1 -v all
Also see [http://xenbits.xen.org/docs/unstable/man/xl.1.html#DOMAIN-SUBCOMMANDS xl(1) search for vcpu-pin]
Name ID VCPU Period Budget
vm1 1 0 300 150
vm1 1 1 400 200
vm1 1 2 10000 4000
vm1 1 3 1000 500

* to change (or check) the scheduling parameters of VCPUs 0 and 3 '''only''', use <code>-v</code>

# xl sched-rtds -d vm1 -v 0 -p 100 -b 50 -v 3 -p 300 -b 150
# xl sched-rtds -d vm1 -v 0 -v 3
Name ID VCPU Period Budget
vm1 1 0 300 150
vm1 1 3 1000 500

For more information and examples, see [http://xenbits.xen.org/docs/unstable/man/xl.1.html#DOMAIN-SUBCOMMANDS the xl manual page] (search for sched-rtds).

=== Credit2 runqueue arrangement and hard-affinity support ===

==== Runqueue arrangement ====

Xen 4.7 allows one to specify how host CPUs are arranged in runqueues, within the Credit2 scheduler. Valid alternatives are <code>core</code>, <code>socket</code>, <code>node</code> and <code>all</code>.
More fine grained runqueue arrangement (as in with <code>core</code>) means more accurate load balancing (e.g., it will deal better with hyperthreading), but also more overhead.

To make this effective (e.g., to use Credit2 per-socket runqueues) add the following to the hypervisor boot command line:

sched=credit2 credit2_runqueue=socket

More information [http://xenbits.xen.org/docs/unstable/misc/xen-command-line.html here] (search for ''credit2_runqueue'')

==== Hard-affinity support ====

In Xen 4.7, Credit2 supports hard-affinity. It can be set by means of the <code>xl vcpu-pin</code> [http://xenbits.xen.org/docs/unstable/man/xl.1.html#DOMAIN-SUBCOMMANDS xl subcommand]. If set for a VCPU, hard-affinity restricts the set of PCPUs where such VCPU can run.

To check that it works, give to the VCPUs of a VM an hard-affinity, by doing as follows:

# xl vcpu-pin 1 all 16-18

And then check where they actually execute, by looking at:

# xl vcpu-list 1
Name ID VCPU CPU State Time(s) Affinity (Hard / Soft)
debian.guest.osstest 1 0 17 r-- 5.3 16-18 / all
debian.guest.osstest 1 1 18 r-- 3.3 16-18 / all

What we want is that the values in the <code>CPU</code> column to be (for VCPUs that are running) '''always''' within the set of PCPUs we specified.


=== Hotplug disk backends (drbd, iscsi, etc.) for HVM guests ===
=== Hotplug disk backends (drbd, iscsi, etc.) for HVM guests ===
If you use drbd, iscsi or other non-default disk backends, try them with HVM guests.
If you use drbd, iscsi, nbd, or other hotplug-script-based disk backends, try them with HVM guests.


Also see
Also see
* [[Storage options]]
* [[Storage options]]
* [http://xenbits.xen.org/docs/unstable/misc/xl-disk-configuration.txt XL DISK CONFIGURATION]
* [http://xenbits.xen.org/docs/unstable/misc/xl-disk-configuration.txt XL DISK CONFIGURATION]

=== KCONFIG support ===
Xen 4.7 introduces the removal of core Xen Hypervisor features at compile time via [https://www.kernel.org/doc/Documentation/kbuild/kconfig-language.txt KCONFIG]. We expect that this functionality is initially only going to be used for security and embedded applications, primarily targeting integration via the [https://www.yoctoproject.org Yocto project]. Yocto integrates with Xen via its [http://git.yoctoproject.org/cgit/cgit.cgi/meta-virtualization/about/ meta-virtualization layer] and the [http://www.yoctoproject.org/docs/current/yocto-project-qs/yocto-project-qs.html xen-image-minimal build support]. The Yocto project currently integrates with Xen 4.6.1 (Yocto kergoth release). We expect that Xen with KCONFIG will be integrated with upstream Yocto, once Xen 4.7.0 has been released.

If you do want to test specific aspects of this new feature before Yocto integration has completed, please send a mail to xen-devel@ and CC the maintainer (cardoe AT cardoe DOT com) for further instructions.


== Specific ARM Test Instructions ==
== Specific ARM Test Instructions ==
Line 99: Line 142:


=== Boards and hardware we do not test in our CI Loop ===
=== Boards and hardware we do not test in our CI Loop ===
{{TODOLeft|
* Check which Allwinner variants are in our Test COLO
}}

Although we do have automated Test Infrastructure for the project, we only include '''rackable''' hardware into our CI Loop. We do have a mixture of Allwinner and Exynos processors in a custom chassis. If you have one of the following boards and want to ensure it runs on Xen 4.7, please make sure you run the [[Xen ARM Manual Smoke Test]] on an RC.
Although we do have automated Test Infrastructure for the project, we only include '''rackable''' hardware into our CI Loop. We do have a mixture of Allwinner and Exynos processors in a custom chassis. If you have one of the following boards and want to ensure it runs on Xen 4.7, please make sure you run the [[Xen ARM Manual Smoke Test]] on an RC.


'''Boards not tested by our CI Loop:''' Allwinner boards with the exception of (TODO: add), DRA7[J6] EVM, Exynos5410, HiKey board from 96boards.org, Mustang (XC-1), OMAP5432, Renesas R-Car H2, Versatile Express and Xilinx Zynq Ultrascale MPSoC
'''Boards not tested by our CI Loop:''' Allwinner sun6i/A31, DRA7[J6] EVM, Exynos5410, HiKey board from 96boards.org, Mustang (XC-1), OMAP5432, Renesas R-Car H2, Versatile Express and Xilinx Zynq Ultrascale MPSoC


We are also not able to include non-production servers that require a legal agreement such as an NDA into our Test Infrastructure.
We are also not able to include non-production servers that require a legal agreement such as an NDA into our Test Infrastructure.


=== TODO: Add headline for specific thing to test ===
=== ACPI support on ARM ===


ACPI support requires a platform with support for ACPI 6.0 (or later). Currently there is no publicly available hardware where this can be tested, with the exception of the [http://www.arm.com/products/tools/models/fast-models/foundation-model.php AEMv8A Foundation Model]. For more information, see
Xen 4.7 supports ... <new feature>
* [[Xen_ARM_with_Virtualization_Extensions/FastModels|Fast Models]]
* [https://wiki.linaro.org/LEG/Engineering/Xen_boot_on_FVP_ACPI_UEFI Xen boot on FVP ACPI UEFI]


=== Wallclock support ===
<Add some instructions on how to test the new feature>
Xen now exposes the wallclock time to guests. Checking the date and time in an ARM guest is all that is needed to verify this, as long as the guest doesn't run ntpdate or doesn't have access to network.


== Specific x86 Test Instructions ==
== Specific x86 Test Instructions ==

=== Huge PV Domains ===
The Xen Project Hypervisor supports starting a Dom0 with very large memory. PV guest limit restrictions of 512GB have been removed to allow the creation of huge PV domains in the TB range via the XL command line interface.

To test, create a PV domain with >512 GB of RAM.


=== Intel Code and Data Prioritization (CDP) ===
=== Intel Code and Data Prioritization (CDP) ===


{{TODOLeft|
{{TODOLeft|
* This section was not written by the author of the relevant features. Thus there may be inaccuracies
* This section was not written by the author of this feature. Thus there may be inaccuracies
* Maybe some instructions on what to test and what one expects to see
* Maybe some instructions on what to test and what one expects to see
}}
}}
Line 132: Line 179:


=== COLO - Coarse Grain Lock Stepping ===
=== COLO - Coarse Grain Lock Stepping ===
COLO or Coarse Grain Lock Stepping is an High Availability solution that builds on top of Remus.
{{TODOLeft|

* This section was not written by the author of the relevant features. Thus there may be inaccuracies
COLO is different from traditional High Availability solutions, which are either based on instruction level lock stepping (excessive overheads) and periodic checkpointing such as [[Remus]] (high network latency, large VM checkpointing overhead). On Xen, COLO builds on top of [[Remus]] and uses a “relaxed approach to checkpointing: in other words, COLO only checkpoints if absolutely necessary, which for many use-cases provides near native performance.
* Are there any restrictions / portions which have not yet been upstreamed?

* Maybe some instructions on what to test and what one expects to see
The COLO Manager component is now part of Xen 4.7, while other components will eventually be part of QEMU (they can be downloaded from a specific git repository).
* Relevant man pages

** [http://xenbits.xen.org/docs/unstable/man/xl.1.html#DOMAIN-SUBCOMMANDS xl(1) search for Remus]
'''Test Instructions''': See [[COLO_-_Coarse_Grain_Lock_Stepping|COLO Docs]] and [[COLO_-_Coarse_Grain_Lock_Stepping#Test_environment_prepare|Test Environment]].
** [http://xenbits.xen.org/docs/unstable/man/xl.conf.5.html xl.conf(5) search for colo.default.proxyscript]
** [http://xenbits.xen.org/docs/unstable/misc/xl-disk-configuration.txt XL DISK CONFIGURATION search for COLO PARAMETERS]
* Relevant Other pages
** [[COLO - Coarse Grain Lock Stepping]]
}}


=== xSplice - binary patching of the hypervisor ===
=== xSplice - binary patching of the hypervisor ===
xSplice is a Xen technology that enables to binary patch the running hypervisor with a '''payload file''' that is intended to primarily contain security updates (but not necessarily only so). v1 of xSplice is in technology preview mode and compile-disabled by default. It also has [[XSplice#TODOs|some restrictions]] on what payloads can be encoded in the '''payload file''', most notably support to generate payloads against .data sections and payloads that NOP (remove) existing functions. Xen 4.7 comes with built in Hypervisor support and the <code>xen-xsplice upload|apply|replace|revert</code> tool to manage payloads (the code is in [http://xenbits.xen.org/gitweb/?p=xen.git;a=tree;f=tools/misc tools/misc]). Additional tools such as <code>xsplice-build</code> to create a payload are at this stage not shipped with Xen, but are available out-of-tree.
* Build Xen with xSplice enabled, see [http://wiki.xen.org/wiki/XSplice#How_to_enable_it Enabling xSplice in hypervisor]
* Patch hypervisor as it is running. There are three simple built-in simple examples, see [http://wiki.xen.org/wiki/XSplice#How_to_build_built-in_examples How to build built-in examples] on how to build, install and test it.
* Alternatively, use the xsplice-tools.git, see [http://wiki.xen.org/wiki/XSplice#Step-by-step Step-by-step] on how to build, install, and test it.
=== TODO: Add headline for specific thing to test ===

Xen 4.7 supports ... <new feature>


To test xSplice, check out:
<Add some instructions on how to test the new feature>
* Build Xen with xSplice enabled, see [[XSplice#How_to_enable_it|Enabling xSplice in hypervisor]]
* Patch hypervisor as it is running. There are three simple built-in simple examples, see [[XSplice#How_to_build_built-in_examples|How to build built-in examples]] on how to build, install and test it.
* Alternatively, see [[XSplice#xsplice-build-tools|xsplice-build-tools]] on how to build, install, and test it.


Major restrictions:
* Works for Linux and FreeBSD dom0's only
* Does not yet work on the ARM architecture
* Cannot generate payloads for patches with .data sections in the ELF file (in other words, patches that introduce global or static variables cannot be encoded)
* Cannot generate payloads that remove (NOP) functions from the hypervisor


{{Anchor|RC}}
{{Anchor|RC}}
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[[Category:Xen_4.7]]
[[Category:Xen_4.7]]
[[Category:Xen]]
[[Category:Xen]]
[[Category:Yocto]]
[[Category:Community]]
[[Category:Community]]
[[Category:Events]]
[[Category:Events]]

Latest revision as of 07:36, 24 April 2017

Icon Info.png If you come to this page before or after the Test Day is completed, your testing is still valuable, and you can use the information on this page to test, post any bugs and test reports to xen-devel@. If this page is more than two weeks old when you arrive here, please check the current schedule and see if a similar but more recent Test Day is planned or has already happened.


What needs to be tested

General things:

  • Making sure that Xen 4.7 compiles and installs properly on different software configurations; particularly on distros
  • Making sure that Xen 4.7, along with appropriately up-to-date kernels, work on different hardware.

For more ideas about what to test, please see Testing Xen.

ARM Smoke Testing

If you use ARM Hardware, which is not widely available or not rackable (and thus not part of our automated test suite), please check out Xen ARM Manual Smoke Test. Helping out to manually test ARM boards (which will only take a few minutes) will guarantee that Xen 4.7 will work on the board that you use. If you want to see which boards need testing, check Xen ARM Manual Smoke Test/Results.

Installing

Getting a RC

For the expressions/examples below, set the following bash/sh/... variable to the release candidate number (e.g. one of rc1, rc2, ... )

RC="<release candidate number>" # rc1, rc2 ...

From xen.git

With a recent enough git (>= 1.7.8.2), just pull from the proper tag (4.7.0-$RC) from the main repo directly:

git clone -b 4.7.0-$RC git://xenbits.xen.org/xen.git

With an older git version (and/or if that does not work, e.g., complaining with a message like this: Remote branch 4.7.0-$RC not found in upstream origin, using HEAD instead), do the following:

git clone git://xenbits.xen.org/xen.git ; cd xen ; git checkout 4.7.0-$RC

From tarball

Download:

 http://bits.xensource.com/oss-xen/release/4.7.0-$RC/xen-4.7.0-$RC.tar.gz 
 http://bits.xensource.com/oss-xen/release/4.7.0-$RC/xen-4.7.0-$RC.tar.gz.sig

Building

Instructions are available for building Xen on Linux, NetBSD, and FreeBSD

Known issues

RC1

Test instructions

General

  • Remove any old versions of Xen toolstack and userspace binaries (including qemu).
  • Remove any Xen-related udev files under /etc because Xen 4.7 doesn't use those anymore.
  • Download and install the most recent Xen 4.7 RC, as described above. Make sure to check the README and INSTALL for changes in required development libraries and procedures. Some particular things to note:

Once you have Xen 4.7 RC installed check that you can install a guest etc and use it in the ways which you normally would, i.e. that your existing guest configurations, scripts etc still work.

USB Support for xl

xl introduces PVUSB support as well as the following commands:

 usbctrl-attach
 usbctrl-detach 
 usbdev-attach
 usbdev-detach 
 usb-list

which corresponds to

 usbctrl=[ "USBCTRL_SPEC_STRING", "USBCTRL_SPEC_STRING", ... ]
 usbdev=[ "USB_SPEC_STRING", "USB_SPEC_STRING", ... ]

as outlined in the xl.cfg(5) man page. For an overview, see Xen USB Passthrough.

RTDS scheduler improvements

The RTDS scheduler was improved in the following way

  • The RTDS scheduler has been changed from a quantum-driven model to an event-driven model, which will not invoke the scheduler unnecessarily: if you use this scheduler, you may want to test your workload using the RC and check whether there are any unexpected side effects
  • Support to get/set RTDS scheduling parameters on a per-VCPU basis has been added to libxl and xl

So, for instance:

  • to see the scheduling parameters of all VCPUs of a VM use -v all
   xl sched-rtds -d vm1 -v all
   Name                        ID VCPU    Period    Budget
   vm1                          1    0       300       150
   vm1                          1    1       400       200
   vm1                          1    2     10000      4000
   vm1                          1    3      1000       500
  • to change (or check) the scheduling parameters of VCPUs 0 and 3 only, use -v
   # xl sched-rtds -d vm1 -v 0 -p 100 -b 50 -v 3 -p 300 -b 150
   # xl sched-rtds -d vm1 -v 0 -v 3
   Name                        ID VCPU    Period    Budget
   vm1                          1    0       300       150
   vm1                          1    3      1000       500

For more information and examples, see the xl manual page (search for sched-rtds).

Credit2 runqueue arrangement and hard-affinity support

Runqueue arrangement

Xen 4.7 allows one to specify how host CPUs are arranged in runqueues, within the Credit2 scheduler. Valid alternatives are core, socket, node and all. More fine grained runqueue arrangement (as in with core) means more accurate load balancing (e.g., it will deal better with hyperthreading), but also more overhead.

To make this effective (e.g., to use Credit2 per-socket runqueues) add the following to the hypervisor boot command line:

   sched=credit2 credit2_runqueue=socket

More information here (search for credit2_runqueue)

Hard-affinity support

In Xen 4.7, Credit2 supports hard-affinity. It can be set by means of the xl vcpu-pin xl subcommand. If set for a VCPU, hard-affinity restricts the set of PCPUs where such VCPU can run.

To check that it works, give to the VCPUs of a VM an hard-affinity, by doing as follows:

   # xl vcpu-pin 1 all 16-18

And then check where they actually execute, by looking at:

   # xl vcpu-list 1
   Name                                ID  VCPU   CPU State   Time(s) Affinity (Hard / Soft)
   debian.guest.osstest                 1     0   17   r--       5.3  16-18 / all
   debian.guest.osstest                 1     1   18   r--       3.3  16-18 / all

What we want is that the values in the CPU column to be (for VCPUs that are running) always within the set of PCPUs we specified.

Hotplug disk backends (drbd, iscsi, etc.) for HVM guests

If you use drbd, iscsi, nbd, or other hotplug-script-based disk backends, try them with HVM guests.

Also see

KCONFIG support

Xen 4.7 introduces the removal of core Xen Hypervisor features at compile time via KCONFIG. We expect that this functionality is initially only going to be used for security and embedded applications, primarily targeting integration via the Yocto project. Yocto integrates with Xen via its meta-virtualization layer and the xen-image-minimal build support. The Yocto project currently integrates with Xen 4.6.1 (Yocto kergoth release). We expect that Xen with KCONFIG will be integrated with upstream Yocto, once Xen 4.7.0 has been released.

If you do want to test specific aspects of this new feature before Yocto integration has completed, please send a mail to xen-devel@ and CC the maintainer (cardoe AT cardoe DOT com) for further instructions.

Specific ARM Test Instructions

Follow Xen_ARM_with_Virtualization_Extensions and Xen_ARM_with_Virtualization_Extensions#Testing

Boards and hardware we do not test in our CI Loop

Although we do have automated Test Infrastructure for the project, we only include rackable hardware into our CI Loop. We do have a mixture of Allwinner and Exynos processors in a custom chassis. If you have one of the following boards and want to ensure it runs on Xen 4.7, please make sure you run the Xen ARM Manual Smoke Test on an RC.

Boards not tested by our CI Loop: Allwinner sun6i/A31, DRA7[J6] EVM, Exynos5410, HiKey board from 96boards.org, Mustang (XC-1), OMAP5432, Renesas R-Car H2, Versatile Express and Xilinx Zynq Ultrascale MPSoC

We are also not able to include non-production servers that require a legal agreement such as an NDA into our Test Infrastructure.

ACPI support on ARM

ACPI support requires a platform with support for ACPI 6.0 (or later). Currently there is no publicly available hardware where this can be tested, with the exception of the AEMv8A Foundation Model. For more information, see

Wallclock support

Xen now exposes the wallclock time to guests. Checking the date and time in an ARM guest is all that is needed to verify this, as long as the guest doesn't run ntpdate or doesn't have access to network.

Specific x86 Test Instructions

Huge PV Domains

The Xen Project Hypervisor supports starting a Dom0 with very large memory. PV guest limit restrictions of 512GB have been removed to allow the creation of huge PV domains in the TB range via the XL command line interface.

To test, create a PV domain with >512 GB of RAM.

Intel Code and Data Prioritization (CDP)

Icon todo.png To Do:
  • This section was not written by the author of this feature. Thus there may be inaccuracies
  • Maybe some instructions on what to test and what one expects to see


Code and Data Prioritization (CDP) Technology is an extension of CAT, which is available on Intel Broadwell and later server platforms. CDP enables isolation and separate prioritization of code and data fetches to the L3 cache in a software configurable manner, which can enable workload prioritization and tuning of cache capacity to the characteristics of the workload. CDP extends Cache Allocation Technology (CAT) by providing separate code and data masks per Class of Service (COS).

For more information see:

COLO - Coarse Grain Lock Stepping

COLO or Coarse Grain Lock Stepping is an High Availability solution that builds on top of Remus.

COLO is different from traditional High Availability solutions, which are either based on instruction level lock stepping (excessive overheads) and periodic checkpointing such as Remus (high network latency, large VM checkpointing overhead). On Xen, COLO builds on top of Remus and uses a “relaxed approach to checkpointing: in other words, COLO only checkpoints if absolutely necessary, which for many use-cases provides near native performance.

The COLO Manager component is now part of Xen 4.7, while other components will eventually be part of QEMU (they can be downloaded from a specific git repository).

Test Instructions: See COLO Docs and Test Environment.

xSplice - binary patching of the hypervisor

xSplice is a Xen technology that enables to binary patch the running hypervisor with a payload file that is intended to primarily contain security updates (but not necessarily only so). v1 of xSplice is in technology preview mode and compile-disabled by default. It also has some restrictions on what payloads can be encoded in the payload file, most notably support to generate payloads against .data sections and payloads that NOP (remove) existing functions. Xen 4.7 comes with built in Hypervisor support and the xen-xsplice upload|apply|replace|revert tool to manage payloads (the code is in tools/misc). Additional tools such as xsplice-build to create a payload are at this stage not shipped with Xen, but are available out-of-tree.

To test xSplice, check out:

Major restrictions:

  • Works for Linux and FreeBSD dom0's only
  • Does not yet work on the ARM architecture
  • Cannot generate payloads for patches with .data sections in the ELF file (in other words, patches that introduce global or static variables cannot be encoded)
  • Cannot generate payloads that remove (NOP) functions from the hypervisor

RC specific things to test

RC2

  • XSM and driver domain: start xl devd in driver domain, and see if there is XSM denial message shown in xl dmesg.

Reporting Bugs (& Issues)

  • Use Freenode IRC channel #xentest to discuss questions interactively
  • Report any bugs / missing functionality / unexpected results.
  • Please put [TestDay] into the subject line
  • Also make sure you specify the RC number you are using
  • Make sure to follow the guidelines on Reporting Bugs against Xen (please CC the relevant maintainers and the Release Manager - wei dot liu2 at citrix dot com).

Reporting success

We would love it if you could report successes by e-mailing xen-devel@lists.xen.org, preferably including:

  • Hardware: Please at least include the processor manufacturer (Intel/AMD). Other helpful information might include specific processor models, amount of memory, number of cores, and so on
  • Software: If you're using a distro, the distro name and version would be the most helpful. Other helpful information might include the kernel that you're running, or other virtualization-related software you're using (e.g., libvirt, xen-tools, drbd, &c).
  • Guest operating systems: If running a Linux version, please specify whether you ran it in PV or HVM mode.
  • Functionality tested: High-level would include toolstacks, and major functionality (e.g., suspend/resume, migration, pass-through, stubdomains, &c)

The following template might be helpful: should you use Xen 4.7.0-<Some RC> for testing, please make sure you state that information!

Subject: [TESTDAY] Test report
 
* Hardware:
 
* Software:

* Guest operating systems:

* Functionality tested:

* Comments:

For example:

Subject: [TESTDAY] Test report
 
* Hardware: 
Dell 390's (Intel, dual-core) x15
HP (AMD, quad-core) x5
 
* Software: 
Ubuntu 10.10,11.10
Fedora 17

* Guest operating systems:
Windows 8
Ubuntu 12.10,11.10 (HVM)
Fedora 17 (PV)

* Functionality tested:
xl
suspend/resume
pygrub

* Comments:
Window 8 booting seemed a little slower than normal.

Other than that, great work!