back to article Xen Project officially ports its hypervisor to Raspberry Pi 4

The Xen Project has ported its hypervisor to the 64-bit Raspberry Pi 4. The idea to do an official port bubbled up from the Xen community and then reached the desk of George Dunlap, chairman of the Xen Project’s Advisory Board. Dunlap mentioned the idea to an acquaintance who works at the Raspberry Pi Foundation, and was told …

  1. Wellyboot Silver badge


    A good excuse reason for a 8Gb model-4 purchase.

    Easy micro farming on a Pi.

    1. Roland6 Silver badge

      Re: Nice

      >Easy micro farming on a Pi.

      I wonder if Xen clustering will seemlessly work out-of-the-box on a Pi cluster...

      1. Martin

        Re: Nice

        Or even seamlessly...

  2. phuzz Silver badge

    ARM or x86?

    So would you only be able to run ARM VMs, or could you run x86 ones on a Pi as well?

    Apple and Microsoft have both cracked it I suppose.

    1. diodesign (Written by Reg staff) Silver badge

      Re: ARM or x86?

      Arm VMs as it runs on Arm hardware. Xen isn't an emulator -- it's a hypervisor. It portions out the underlying hardware into partitions that each operating system runs within.


    2. Anonymous Coward
      Anonymous Coward

      Re: ARM or x86?

      Guys! Don't downvoted him/her for asking a question!

      1. Anonymous Coward
        Anonymous Coward

        Re: ARM or x86?

        I've resisted the BOFH urge to downvote here just to mess with you.

        Instead, an upvote because I actually agree.

      2. phuzz Silver badge

        Re: ARM or x86?

        Thanks for you concer, but I'm used to it. Pretty much any comment that gets more than a couple of upvotes seems to attract downvotes as well. I don't think there's anything you could say that wouldn't attract downvotes form someone.

        1. iGNgnorr

          Re: ARM or x86?

          Sometimes I wish I could downvote and upvote at the same time, just to keep things in balance.

  3. druck Silver badge
    Thumb Up

    RISC OS / Linux Chimera

    Hopefully with a hypervisor we can get RISC OS running on one core, Linux on the rest, and have the best of both worlds on one tiny British box.

  4. LeahroyNake

    Nice achievement

    I personally think the best version is the Zero W followed by the 3b+

    I have the 3b running pihole DNS, mysql and apache for home monitoring temps etc. The zero is in the garden solar powered with a 12v battery and controls the water feature (it's not a pond, I'm lot allowed one of them :) pumps and heaters to keep the fishies happy. It was fun setting it all up for under £100, kept me occupied for several days while on furlough:)

  5. milliganp

    Beautiful Madness

    When someone says "why would you do that", you have to be over 50 to explain that you once ran a mid sized businesses' core IT on a machine less powerful than a Pi 4.

    1. Tom 7

      Re: Beautiful Madness

      I helped run a couple of massive nt servers that fed 300+ PCS around the place. The pi zero is easily faster and has more ram. The SSD has a considerable advantage over the spinning rust too!

      1. Anonymous Coward
        Anonymous Coward

        Re: Beautiful Madness

        Econet. End of discussion.

    2. rag2

      Learning to code

      Or twenty years older than that to understand that a Raspberry Pi Zero(W) plus power bank is just soooo much smaller, lighter, cheaper, and more powerful than the machine that you learnt to program on. Also, there's no danger of spilt card decks!

      1. Anonymous Coward
        Anonymous Coward

        Re: Learning to code

        But I liked knitting those nets with ring ferrites..

        (are we heading towards the four Yorkshire men again ? :) )

    3. katrinab Silver badge

      Re: Beautiful Madness

      How does a pair of Pentium Pros compare with a Pi 4? That was just over 20 years ago.

      1. Wayland

        Re: Beautiful Madness

        I was provided a dual Pentium II 233MHz machine with 256MB RAM and 10GB Hard drive on Windows NT4 which at the time was the most powerful machine the corporation could provide.

        This brought the compile time for a CD ROM based manual down from 14 hours to 3 hours.

        I then found the bit of code which was making it slow which made it do the job in 10 minutes!

        A PI linked to a decent storage drive would definitely run that compile. However I don't think it would work well to an SD card.

      2. Buzzword

        Re: Beautiful Madness

        Looking at floating-point performance alone, the RPi 4 is equivalent to an Intel Core 2 Duo from circa 2007.

  6. Glen 1

    Will be interesting to see how the GPIO is handled.

    1. chuBb.

      I expect they will MUX that bit up ;-)

    2. Anonymous Coward
      Anonymous Coward

      Is GPIO when your doctor puts something inside you as well as taking something out?

      (I may be on the wrong site).

  7. Dwarf

    Cool points for the developers

    A good evolution given where the CPU market seems to be heading and "cool points" for the developers for pulling this off.

    However, with a cupboard full of different PI versions since they first came out and several stuck with Velcro to different things around the house, I can't see a need to virtualise them as its often the form factor, options for physical placement and access to the various ports that is most important.

    If the memory capacity keeps increasing, then I might change my mind, but I'd expect that most would probably want to containerise rather than virtualise and docker has been on them for a long time now. IO rates to the SD card will also be a problem, so I guess definitely a Pi4 only solution where USB3 exits

    There are a couple of areas where I expect this will be extended in the coming months.

    1. A virtualised ARM based mobile phone, one virtual one for the way through the airport and one the real one for when you get there.

    2. Some form of malware / rootkit that uses the new virtualisation as this always seems to follow such evolutions.

    1. fajensen

      Re: Cool points for the developers

      Once you have a ... murder, shoal, ... mob ...??? ... of feisty PI's around the house, then you gotta manage them. Hopefully with something like Puppet or CFEngine. That tool will need a server.

      Probably one also needs an apt-cache, like apt-cacher-ng. Which, for simplicity, is Another server.

      Those would fit neatly into a PI-4, especially when virtualised. In my experience, management tools tend to be quirky and some of them (CFEngine?) are even installed from a shell-script rather than a package, creating "a mess" from the start on a packetized system. This way we can keep the mess in a container.

      1. Dwarf

        Re: Cool points for the developers


        Nah, that's where a good Internet connection, a couple of cron scripts and a NAS comes in. Use the right tools for the job and keep it simple. Puppet and the like is not require

        Most of the builds are for specific tasks (Kodi, Asterisk, VPN, some home automation, etc) and hence already packaged up by the providers or me and there is no ongoing platform management via some form of DSC tool, they just use their own UI / cmd line once to get the base config and then never need to fiddle again. This is why I said no need for virtual Pi

        Just thinking more on this, it a Pi container called a bowl or a lunchbox ?

    2. Wayland

      Re: Cool points for the developers

      The SD card is a big problem, those things are horrible. OK as a floppy drive but terrible as a hard drive. I think Xen on ARM is the goal here for the server market but Xen on PI is very cool. If you want performance then Docker or LXC containers is the way to virtualize. It's just that it's easier for the user if they get a whole virtual PI rather than have to use a container.

  8. Anonymous Coward
    Anonymous Coward


    Doesn’t KVM already support the Pi?

  9. Doug 3

    Can you imagine a Beowulf Cluster of one of these!

  10. fredesmite2

    Why ???

    Arm KVM ... full virtualization, is already there.

    1. Richard 12 Silver badge

      Choice is good

      Maybe some people just prefer the Xen UI?

      It's objectively better if there is more than one option, it pushes both projects to improve.

      It also sounds like the Linux kernel previously didn't support some of the things needed for full virtualization (eg of DMA) on some types of hardware.

      Perhaps KVM will now also be improved because it won't have to use slower workarounds?

      1. Anonymous Coward
        Anonymous Coward

        Re: Choice is good

        Xen never got upstreamed into the Linux kernel because it’s bloated. It has it’s own memory management, scheduler, IPC model, and so forth.

        It turns out that what starts as “a minimal hypervisor” very quickly becomes an entire Kernel of its own. There are other projects that seem to suffer the same fate (Grub and BusyBox spring to mind).

        KVM solves this problem by just treating a VM as a Linux process with a funny ABI.

        Sometimes the choice is just wrong, unfortunately. Maybe there is something useful in here, but I doubt there’s anything KVM couldn’t already do...

        1. hack3rcon

          Re: Choice is good

          KVM? Is you mean VirtualBox?

          KVM is not a real Hypervisor.

          1. Anonymous Coward
            Anonymous Coward

            Re: Choice is good

            Eh? What do you think KVM is?

            From Wikipedia:

            "Kernel-based Virtual Machine (KVM) is a virtualization module in the Linux kernel that allows the kernel to function as a hypervisor. "

            1. hack3rcon

              Re: Choice is good

              Yes. I see.

              I don't know why a user should use KVM when a good tool like VirtualBox or VMware Workstation exist!!!

              If a user need a real hypervisor, then Xen and its derivatives or ESXi are good options.

              1. Anonymous Coward
                Anonymous Coward


                Annoying reuse of existing acronym? see KVM switch

                If the VMM was not in the kernal then it would not use hardware seperation so K here is redundant unless it is as I thought because KVM came with KDE and they prefix their suite's executables with a K but apprantly not

              2. Anonymous Coward
                Anonymous Coward

                Re: Choice is good

                KVM is free?

            2. AndyD 8-)₹

              Re: Choice is good

              Eh? What do you think KVM is?

              Keyboard Video Mouse?

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