VirtualBox KVM Backend Adds Support For SR-IOV Graphics

[Quackdoc]

A KVM back-end for VirtualBox actually sounds quite interesting. I haven't used VirtualBox in years and these days I mostly use KVM, which is fine for servers. But the Virtual Machine Manager doesn't give anywhere near desktop-like performance for GUI applications.

thats just because virtual machine manager is bad. spice isn't great in the first place (it's being somewhat replaced by a dbus based protocol) and setting up proper hwaccel is kinda a pain, Gnome Boxes is marginally better in this regard but iirc it uses spice too so perf still isn't superb, qemu + gtk/sdl is still the best since we have no real dbus guis yet (there is a prototype GTK4 based gui) (You can follow this ticket to see if they ever implement it https://gitlab.gnome.org/GNOME/gnome...issues/966)

Intel! Since Alder Lake!!

sadly it doesnt seem to be availible on DG2, at least not wired up in any way

[caligula]

I can't help but wonder why? I mean im always for virtualization news, but virtualbox has been essentially dead and offers very little over qemu besides a gui and 3d acceleration, the latter which is currently a WIP with virgl to support opengl and d3d10, Vulkan is planned eventually which would pave the way for zink + d3d10 (potentially able to be expanded to d3d11 since 11 was more incremental improvements so it can be built on top of the d3d10 work) support which should beat out pretty much any VMM in terms of perf.

So I really have to question why not just try and help the virgl work, and make a gui for qemu?

Virtualbox also works on Mac and windows. E.g. if you have a VM for students, they can install the same VM on all OSes. With qemu it's much harder.

[Quackdoc]

Virtualbox also works on Mac and windows. E.g. if you have a VM for students, they can install the same VM on all OSes. With qemu it's much harder.

qemu works perfectly fine on windows and mac...

[darkbasic]

Intel! Since Alder Lake!!

Before getting too excited:
1) It's for APUs only.
2) It's not mainline yet.

[mppix]

I can't help but wonder why? I mean im always for virtualization news, but virtualbox has been essentially dead and offers very little over qemu besides a gui and 3d acceleration, the latter which is currently a WIP with virgl to support opengl and d3d10, Vulkan is planned eventually which would pave the way for zink + d3d10 (potentially able to be expanded to d3d11 since 11 was more incremental improvements so it can be built on top of the d3d10 work) support which should beat out pretty much any VMM in terms of perf.

So I really have to question why not just try and help the virgl work, and make a gui for qemu?

SR-IOV is better. It exposes the GPU to guests similar to a CPU. Main limitation is that dGPU vendors limit the functionality to their business products.

However, GPU acceleration in the guest (in whatever form) does not solve the response time problem. A guest could run huge framerates just for the display protocol to become the bottleneck.
For gaming, a solution like 'lookingglass' (zero copy frames from host to guest) is needed.

[mppix]

thats just because virtual machine manager is bad. spice isn't great in the first place (it's being somewhat replaced by a dbus based protocol) and setting up proper hwaccel is kinda a pain, Gnome Boxes is marginally better in this regard but iirc it uses spice too so perf still isn't superb, qemu + gtk/sdl is still the best since we have no real dbus guis yet (there is a prototype GTK4 based gui) (You can follow this ticket to see if they ever implement it https://gitlab.gnome.org/GNOME/gnome...issues/966)

What is wrong with spice? Its massively better than VNC.

[Quackdoc]

SR-IOV is better. It exposes the GPU to guests similar to a CPU. Main limitation is that dGPU vendors limit the functionality to their business products.

However, GPU acceleration in the guest (in whatever form) does not solve the response time problem. A guest could run huge framerates just for the display protocol to become the bottleneck.
For gaming, a solution like 'lookingglass' (zero copy frames from host to guest) is needed.

I am very intimate with the benefits of SR-IOV I don't understand the point of adding it to vbox

What is wrong with spice? Its massively better than VNC.

Spice is still a slow protocol with a bunch of legacy crap around it, Yes, it's better then VNC, but it pales in comparison to something gtk or dbus output. Spice should be abandoned post haste in exchange for some other kind of VDI appropriate protocol. In the past when the patches were first merged I experimented briefly wiring up dbus to gstreamer with great results (keyboard and mouse were not wired up at this time) having a proper utility to wire it up to (for instance sunshine/moonlight) would be a far better solution then Spice is.

[Luis Alvarado]

Would this be related by chance to use, for example, an Nvidia card at the same time on both, a VM and the HOST?

Like an IOMMU but without the host loosing access to it, but instead sharing it with the VM?

[dragorth]

Would this be related by chance to use, for example, an Nvidia card at the same time on both, a VM and the HOST?

Like an IOMMU but without the host loosing access to it, but instead sharing it with the VM?

Yes, if the Nvidia card supports SR-IOV. Their Enterprise cards do support this, so maybe that would work. But their consumer cards are blocked from doing this.

[Luis Alvarado]

Thank you. I have a 4090 but did not know that the hardware needed to support that.