6 ms·

Enabling KVM Virtualization for Raspberry Pi 2

59 points by sergiolp 12y ago

dijit 12y ago
it's dead jim.
kogepathic 12y ago
Does anyone have a mirror? I think we DDoS'd OP's site.
- sergiolp 12y ago
  Sorry, we've underestimated the attention this post was going to get. We've just assigned more resources to that machine. Let's hope that'll be enough to bear with the warm, warm hug of Hacker News ;-)
graystevens 12y ago
Google cached copy http://webcache.googleusercontent.com/search?q=cache:ZE1-Hy148zEJ:blog.flexvm.es/%3Fp%3D167+&cd=4&hl=en&ct=clnk&gl=uk http://webcache.googleusercontent.com/search?q=cache:ZE1-Hy1...
- nodata 12y ago
  text version: http://webcache.googleusercontent.com/search?q=cache:ZE1-Hy148zEJ:blog.flexvm.es/%3Fp%3D167&hl=en&gl=uk&strip=1 http://webcache.googleusercontent.com/search?q=cache:ZE1-Hy1...
voltagex_ 12y ago
Code is at https://github.com/slp/rpi2-hyp-boot https://github.com/slp/rpi2-hyp-boot
ipedrazas 12y ago
Is this blog running on a Raspberry???
mkoryak 12y ago
Last line of the article is "And that’s it, now you can extract the full potential of your Raspberry Pi 2!" Can someone explain this to me? I know almost nothing about virtualization, but isn't it be definition slower than straight up OS install?
- detaro 12y ago
  It's probably not meant about performance, but more along the lines of "now you can use every feature it has".
- vidarh 12y ago
  The overhead can be very small, but the overhead is besides the point. The point is that it for example allows you to run things in parallel that you otherwise would need to reboot to run. E.g. testing a different OS or distribution.
- sergiolp 12y ago
  Of course, a virtualized Guest will have a performance penalty. With that phrase I meant that, following this guide, you can make use of the Virtualization Extensions from the Cortex-A7 which powers the Raspberry Pi 2. This is pretty useful for running multiple isolated services (such as a media server and an ownCloud instance), doing some kernel hacking, or testing a variety of ARMv7 distributions.
teekert 12y ago
Noob questions: Can I run Windows like this? Does it enable Qemu support? Can a non ARM OS be emulated in ARM hardware? (Probably not by hardware extensions, right?)
- omh 12y ago
  This virtualisation is just for running ARM guests, so you can't run Windows. There will apparently be an ARM version of Windows 10 for the pi, but that's a cut down version for internet of things type apps. You can emulate x86 on ARM with something like QEMU. But the performance wouldn't be good enough for any modern OS.
fulafel 12y ago
So is the interrupt thing a real HW bug in the RPi CPU or might this be solvable with some setup magic on the VC black box side? And why does isolating one core on the host side suffice, without restricting which cores the guest can run on? He's running the guest SMP enabled in the example posted.
- agwa 12y ago
  The author does restrict which core the guest can run on, with a patch to qemu. And the guest is limited to a single CPU/core (-smp 1).
- AlyssaRowan 12y ago
  Hmm. Could be the mailbox communication for VPU<->CPU communication timing out? BCM should be able to repro and fix that. They could also be able to make enabling HYP mode less of a hack. As for the lack of an accessible GIC, the VPU runs ThreadX, which has a software timer infrastructure: no reason I can see they couldn't expose those if they wanted.
sciurus 12y ago
Great hack, but I'm disappointed that it's this complicated.
wukoje 12y ago
Why not just use containerization instead? it is the best fit for a RB pi in any aspect. Almost no performance penalty and incredible use cases. Imagine having a fast bare OS on it and deploying remotely containers trough tutum web interface. IoT start to make sense now? :)
- simcop2387 12y ago
  This ends up really useful if you want to run a different operating system at the same time. It might make it possible to run Windows RT and Linux at the same time on the RPi2 (or as the author is wanting, NetBSD and Linux). This is something that cannot be done by a container system. For practical setups though, you are correct you'll get a better experience with the lower overhead of a container system and likely better support. Being able to work around the hardware issue on the RPi2 though to enable this is something I didn't think was really doable. Congrats to the author, this is a really great development.
  - tmzt 12y ago
    Would be pretty cool to have colinux on WinRT if you wanted to go the other way. There were also some demos of Android and Windows CE running on the same hardware before ARM had intentional hardware virtualization support.

59 points by sergiolp 12y ago

dijit 12y ago

it's dead jim.

kogepathic 12y ago

Does anyone have a mirror? I think we DDoS'd OP's site.

sergiolp 12y ago
Sorry, we've underestimated the attention this post was going to get. We've just assigned more resources to that machine. Let's hope that'll be enough to bear with the warm, warm hug of Hacker News ;-)

graystevens 12y ago

Google cached copy http://webcache.googleusercontent.com/search?q=cache:ZE1-Hy148zEJ:blog.flexvm.es/%3Fp%3D167+&cd=4&hl=en&ct=clnk&gl=uk http://webcache.googleusercontent.com/search?q=cache:ZE1-Hy1...

nodata 12y ago
text version: http://webcache.googleusercontent.com/search?q=cache:ZE1-Hy148zEJ:blog.flexvm.es/%3Fp%3D167&hl=en&gl=uk&strip=1 http://webcache.googleusercontent.com/search?q=cache:ZE1-Hy1...

voltagex_ 12y ago

Code is at https://github.com/slp/rpi2-hyp-boot https://github.com/slp/rpi2-hyp-boot

ipedrazas 12y ago

Is this blog running on a Raspberry???

mkoryak 12y ago

Last line of the article is "And that’s it, now you can extract the full potential of your Raspberry Pi 2!" Can someone explain this to me? I know almost nothing about virtualization, but isn't it be definition slower than straight up OS install?

detaro 12y ago
It's probably not meant about performance, but more along the lines of "now you can use every feature it has".
vidarh 12y ago
The overhead can be very small, but the overhead is besides the point. The point is that it for example allows you to run things in parallel that you otherwise would need to reboot to run. E.g. testing a different OS or distribution.
sergiolp 12y ago
Of course, a virtualized Guest will have a performance penalty. With that phrase I meant that, following this guide, you can make use of the Virtualization Extensions from the Cortex-A7 which powers the Raspberry Pi 2. This is pretty useful for running multiple isolated services (such as a media server and an ownCloud instance), doing some kernel hacking, or testing a variety of ARMv7 distributions.

teekert 12y ago

Noob questions: Can I run Windows like this? Does it enable Qemu support? Can a non ARM OS be emulated in ARM hardware? (Probably not by hardware extensions, right?)

omh 12y ago
This virtualisation is just for running ARM guests, so you can't run Windows. There will apparently be an ARM version of Windows 10 for the pi, but that's a cut down version for internet of things type apps. You can emulate x86 on ARM with something like QEMU. But the performance wouldn't be good enough for any modern OS.

fulafel 12y ago

So is the interrupt thing a real HW bug in the RPi CPU or might this be solvable with some setup magic on the VC black box side? And why does isolating one core on the host side suffice, without restricting which cores the guest can run on? He's running the guest SMP enabled in the example posted.

agwa 12y ago
The author does restrict which core the guest can run on, with a patch to qemu. And the guest is limited to a single CPU/core (-smp 1).
AlyssaRowan 12y ago
Hmm. Could be the mailbox communication for VPU<->CPU communication timing out? BCM should be able to repro and fix that. They could also be able to make enabling HYP mode less of a hack. As for the lack of an accessible GIC, the VPU runs ThreadX, which has a software timer infrastructure: no reason I can see they couldn't expose those if they wanted.

sciurus 12y ago

Great hack, but I'm disappointed that it's this complicated.

wukoje 12y ago

Why not just use containerization instead? it is the best fit for a RB pi in any aspect. Almost no performance penalty and incredible use cases. Imagine having a fast bare OS on it and deploying remotely containers trough tutum web interface. IoT start to make sense now? :)

simcop2387 12y ago
This ends up really useful if you want to run a different operating system at the same time. It might make it possible to run Windows RT and Linux at the same time on the RPi2 (or as the author is wanting, NetBSD and Linux). This is something that cannot be done by a container system. For practical setups though, you are correct you'll get a better experience with the lower overhead of a container system and likely better support. Being able to work around the hardware issue on the RPi2 though to enable this is something I didn't think was really doable. Congrats to the author, this is a really great development.
- tmzt 12y ago
  Would be pretty cool to have colinux on WinRT if you wanted to go the other way. There were also some demos of Android and Windows CE running on the same hardware before ARM had intentional hardware virtualization support.