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QEMU 7.0

qemu.org

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Re: QEMU 7.0

#71

Post by anderspitman »

jstarks wrote: post #68
anderspitman wrote: post #37

QEMU is absolutely incredible. I think its most undersold feature is the fact that it runs on Windows hosts[0] thanks to MinGW. This in itself isn't unique, but what is unique is that by default it runs entirely without admin privileges. I've been playing with shipping server apps as QEMU VMs and it works surprisingly well. QEMU itself is small enough (~20MB) to ship the entire thing with the app, including DLLs. Wit…

Yes, we were very excited to get WHP (Windows Hypervisor Platform) support integrated. Before that, you could only use it with the HAXM hypervisor on Windows, which conflicts with the Windows hypervisor (used by Hyper-V, WSL2, and the Windows Subsystem for Android).

It's huge honestly. Do you think there's any chance of Microsoft enabling WHP by default? I think using microVMs for sandboxing apps could be amazing for securing user applications, but currently you still have to instruct users how to turn it on and reboot.

Also, how active is the WHP work in QEMU? Is it mostly done by the QEMU folks or inside MS? Is anyone other than Android actively banging on it?

Sorry for the deluge of questions but I think there's a ton of untapped potential in this tech.

Re: QEMU 7.0

#72

Post by password4321 »

cpach wrote: post #64
greatquux wrote: post #34

Earlier quoted context omitted.

I work for an MSP that uses Datto to back up lots of servers and saved our bacon after the Kaseya hack! (Ironic how they're buying you now.) And I remember when you were using VBox, QEMU is much improved. Having QEMU boot up the backed-up VM to a screenshot that you can just email to us really helps prove to auditors that yes, our backups are tested! Now just replace all the spinning hard disks in your data centers w…

I didn’t follow… Who’s buying what?

per Google:

https://www.kaseya.com/datto-to-be-acquired-by-kaseya (Apr 2022)

https://en.wikipedia.org/wiki/Kaseya_VSA_ransomware_attack (Jul 2021)

Re: QEMU 7.0

#73

Post by Twirrim »

binwiederhier wrote: post #14

Since QEMU devs/maintainers are lurking, i just want to say thank you for a fantastic project. I work for a company (Datto) that backs up Windows/Linux machines, which can then later be run as VMs for disaster recovery. Our product heavily relies on QEMU, and would be significantly harder to implement and maintain without it (believe me, it was built around VBox in the past). Thank you!

How do you handle the missing drivers when it comes to running under the VM? Do you modify the backups, or do you opt for emulation with good old standard hardware instead?

Windows is.. Windows. Always pain with drivers there. Linux should be the easiest story, but since RHEL7 (and the derivatives from there), dracut has defaulted to "host-only" mode which leaves the initramfs so skinny and devoid of drivers not related to the host.

Re: QEMU 7.0

#74

Post by zimbatm »

anderspitman wrote: post #37

QEMU is absolutely incredible. I think its most undersold feature is the fact that it runs on Windows hosts[0] thanks to MinGW. This in itself isn't unique, but what is unique is that by default it runs entirely without admin privileges. I've been playing with shipping server apps as QEMU VMs and it works surprisingly well. QEMU itself is small enough (~20MB) to ship the entire thing with the app, including DLLs. Wit…

QEMU and FFmpeg are sort of in this category of tooling that are incredibly powerful. The amount of things you can do with it, the technical achievement, is incredible.

And the only thing holding them back is that you need 3 pages of command-line arguments to invoke them properly :-)

(EDIT: I was just reminded that both were started by the same author: Fabrice Ballad)

Re: QEMU 7.0

#75

Post by forty »

zimbatm wrote: post #74
anderspitman wrote: post #37

QEMU is absolutely incredible. I think its most undersold feature is the fact that it runs on Windows hosts[0] thanks to MinGW. This in itself isn't unique, but what is unique is that by default it runs entirely without admin privileges. I've been playing with shipping server apps as QEMU VMs and it works surprisingly well. QEMU itself is small enough (~20MB) to ship the entire thing with the app, including DLLs. Wit…

QEMU and FFmpeg are sort of in this category of tooling that are incredibly powerful. The amount of things you can do with it, the technical achievement, is incredible. And the only thing holding them back is that you need 3 pages of command-line arguments to invoke them properly :-) (EDIT: I was just reminded that both were started by the same author: Fabrice Ballad)

I'm not sure if you chose those two software randomly, so just in case you did: they both have the same creator, Fabrice Bellard

Re: QEMU 7.0

#76

Post by anderspitman »

hoistbypetard wrote: post #36
anderspitman wrote: post #32

Earlier quoted context omitted.

I agree with you, but I also think it's pretty impressive that Fabrice has started multiple projects that many other people have devoted their entire careers to expanding/maintaining. Almost seems to challenge the common assertion that execution is more important than a great idea.

These weren't un-executed ideas, though. I think it lines up very well with my general sense that the best way to get to a really good implementation of something is to publish one that's lacking in some way that annoys people. Then you have an idea plus something people can contribute work to improve.

> These weren't un-executed ideas, though

I think you're straw-manning what I said a bit.

Re: QEMU 7.0

#77

Post by egberts1 »

stsquad wrote: post #70
egberts1 wrote: post #59

My only lamentation of QEMU is their rapid development. (I did say “only”). We had an open source CPU emulator (of many CPU arch) called “Unicorn” that was a heavy test instrumentation points inserted widely throughout and into QEMU 4.0. I spent 2 solid years on these dynamic API bindings of Unicorn into QEMU. It was an awesome piece of SW that allowed us to recreate the behavior of malware. Asking the QEMU team to i…

The upstream now has TCG plugins ( https://qemu.readthedocs.io/en/latest/devel/tcg-plugins.html ) which allow for a degree of instrumentation. The implementation is architecture agnostic and also tested within the code base. There are still features missing but it does provide a base for dynamic analysis of guest code.

Right but there are many analysis code written under Unicorn-engine that are architecture-specific.

I do not think we could do that yet with the new QEMU TCG plug-in framework.

Re: QEMU 7.0

#78

Post by rubyist5eva »

cpach wrote: post #23
rubyist5eva wrote: post #21

How’s macOS virtualization performance these days? Had to pony up for a Parallels Desktop license as QEMU was 2-3x slower and just wasn’t up to snuff for daily driving on my dev machine.

From my toying around with it it seems quite good. But I haven’t done any stress-testing/benchmarking. NB: Important to use the HVF accelerator! Otherwise it will surely be slow. See https://wiki.qemu.org/Features/HVF

Any idea if this is enabled by default (or how to check/enable it manually) on UTM.app? I have the "Use Hypervisor" option enabled on the VM but it's dreadfully slow even with just a headless linux server.

Re: QEMU 7.0

#79

Post by password4321 »

anderspitman wrote: post #37

QEMU is absolutely incredible. I think its most undersold feature is the fact that it runs on Windows hosts[0] thanks to MinGW. This in itself isn't unique, but what is unique is that by default it runs entirely without admin privileges. I've been playing with shipping server apps as QEMU VMs and it works surprisingly well. QEMU itself is small enough (~20MB) to ship the entire thing with the app, including DLLs. Wit…

https://github.com/intel/haxm looks cool, thanks! Windows Home support saves a few bucks.

Re: QEMU 7.0

#80

Post by anderspitman »

password4321 wrote: post #79
anderspitman wrote: post #37

QEMU is absolutely incredible. I think its most undersold feature is the fact that it runs on Windows hosts[0] thanks to MinGW. This in itself isn't unique, but what is unique is that by default it runs entirely without admin privileges. I've been playing with shipping server apps as QEMU VMs and it works surprisingly well. QEMU itself is small enough (~20MB) to ship the entire thing with the app, including DLLs. Wit…

https://github.com/intel/haxm looks cool, thanks! Windows Home support saves a few bucks.

I wonder if there's actually any reason to use HAXM these days, since WHP ships with windows and works for both Intel and AMD CPUs?
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