VirGL is definitely an interesting project, but all one has to do to get GPU passthrough working (from a Linux QEMU host to any guest OS) is: 1.) research a cheap, secondary GPU that is natively supported by the guest OS, 2.) plug such a secondary GPU into a PCIe slot on the host and hook it up to the primary monitor with a secondary cable (D-Sub vs. DVI, etc.), 3.) setup Linux to ignore the secondary GPU at boot and configure a QEMU VM for the GPU passthrough. The whole process takes perhaps [edit: "a few"] hours and as works flawlessly, with no stability issues [edit: "at least with Asus motherboards"]. (Switching across the two GPU cables can be accomplished in software by using Display Data Channel /DDC/ utilities and switching keyboard/mouse can be accomplished by using evdev /event device/ passthrough.) More information: https://github.com/kholia/OSX-KVM/blob/master/notes.md#gpu-p...
VirGL – A virtual 3D GPU for use inside QEMU virtual machines
21–30 of 84 posts
Re: VirGL – A virtual 3D GPU for use inside QEMU virtual machines
#22VirGL is definitely an interesting project, but all one has to do to get GPU passthrough working (from a Linux QEMU host to any guest OS) is: 1.) research a cheap, secondary GPU that is natively supported by the guest OS, 2.) plug such a secondary GPU into a PCIe slot on the host and hook it up to the primary monitor with a secondary cable (D-Sub vs. DVI, etc.), 3.) setup Linux to ignore the secondary GPU at boot and…
Except that requires IOMMU which is not always available nor is it always reliable on consumer motherboards.
Re: VirGL – A virtual 3D GPU for use inside QEMU virtual machines
#23VirGL is definitely an interesting project, but all one has to do to get GPU passthrough working (from a Linux QEMU host to any guest OS) is: 1.) research a cheap, secondary GPU that is natively supported by the guest OS, 2.) plug such a secondary GPU into a PCIe slot on the host and hook it up to the primary monitor with a secondary cable (D-Sub vs. DVI, etc.), 3.) setup Linux to ignore the secondary GPU at boot and…
See https://looking-glass.io/ to get around directly connecting monitors
But forwarding real GPUs limits the number of VMs and can cause stability issues if unlucky - PCIe device bugs, especially reset bugs, are not unusual. Had problems with e.g. a forwarded rx580 that would require a hard reboot of the host to fix...
Things like Intel GVT-g and VirGL are better solutions, when they can be used.
Re: VirGL – A virtual 3D GPU for use inside QEMU virtual machines
#24VirGL is definitely an interesting project, but all one has to do to get GPU passthrough working (from a Linux QEMU host to any guest OS) is: 1.) research a cheap, secondary GPU that is natively supported by the guest OS, 2.) plug such a secondary GPU into a PCIe slot on the host and hook it up to the primary monitor with a secondary cable (D-Sub vs. DVI, etc.), 3.) setup Linux to ignore the secondary GPU at boot and…
Except that requires IOMMU which is not always available nor is it always reliable on consumer motherboards.
Good point, but I believe that was a serious problem 10 years ago, while these days virtually any decent motherboard properly supports IOMMU, consumer-grade boards included - e.g. any Asus motherboard should work perfectly.
Re: VirGL – A virtual 3D GPU for use inside QEMU virtual machines
#25Its virtual... but passthrough, I would like to see something thats virtual but runs on pure cpu x86 or arm, do not care how slow.
See LLVMpipe a little ways up the list in the left hand pane. It should do exactly what you're looking for. It's worth noting the terminology "passthrough" means something else in this particular context and VirGL is not considered a passthrough solution (as noted in the "out of scope" section). VirGL is a form of paravirtualization often called "API remoting".
Yes, llvmpipe or lavapipe is awesome. It is fully Vulkan 1.3 compliant and the performance is more than adequate for GUI apps, simple 3d apps or running your gfx tests in a CI environment without a GPU.
Re: VirGL – A virtual 3D GPU for use inside QEMU virtual machines
#26I tried to use it 1.5years ago when playing CSGO inside a VM. It worked, but the delay (between mouse movements and changes on the screen) was quickly raising to something like 0.5-1s.
It required some host daemon to be cooperating with qemu back then (virgldeamonsthsth).
Re: VirGL – A virtual 3D GPU for use inside QEMU virtual machines
#27VirGL is definitely an interesting project, but all one has to do to get GPU passthrough working (from a Linux QEMU host to any guest OS) is: 1.) research a cheap, secondary GPU that is natively supported by the guest OS, 2.) plug such a secondary GPU into a PCIe slot on the host and hook it up to the primary monitor with a secondary cable (D-Sub vs. DVI, etc.), 3.) setup Linux to ignore the secondary GPU at boot and…
Except that requires IOMMU which is not always available nor is it always reliable on consumer motherboards.
IOMMU is a integrated CPU feature, so consumer motherboards do not affect reliability - they just make the setting available.
IOMMU is also required for various modern security features, and M$ requires it for certification nowadays to protect against DMA vulnerabilities (heard of thunderbolt?).
Re: VirGL – A virtual 3D GPU for use inside QEMU virtual machines
#28VirGL is definitely an interesting project, but all one has to do to get GPU passthrough working (from a Linux QEMU host to any guest OS) is: 1.) research a cheap, secondary GPU that is natively supported by the guest OS, 2.) plug such a secondary GPU into a PCIe slot on the host and hook it up to the primary monitor with a secondary cable (D-Sub vs. DVI, etc.), 3.) setup Linux to ignore the secondary GPU at boot and…
See https://looking-glass.io/ to get around directly connecting monitors But forwarding real GPUs limits the number of VMs and can cause stability issues if unlucky - PCIe device bugs, especially reset bugs, are not unusual. Had problems with e.g. a forwarded rx580 that would require a hard reboot of the host to fix... Things like Intel GVT-g and VirGL are better solutions, when they can be used.
> See https://looking-glass.io/ to get around directly connecting monitors
Interesting, thanks for the link!
> Had problems with e.g. a forwarded rx580
I've been forwarding Sapphire Radeon RX 580 Pulse to both Windows and macOS for literally years and, except for the specific problem of host sleep/wake, had no problems whatsoever. Perhaps try an Asus motherboard?
> Things like Intel GVT-g and VirGL are better solutions, when they can be used.
Sure, when software solutions are available and stable (and there's no need for near-native GPU performance), they are definitely easier to work with. However, as of today, GPU passthrough is probably the only solution available for a daily driver.
Re: VirGL – A virtual 3D GPU for use inside QEMU virtual machines
#29Earlier quoted context omitted.
See LLVMpipe a little ways up the list in the left hand pane. It should do exactly what you're looking for. It's worth noting the terminology "passthrough" means something else in this particular context and VirGL is not considered a passthrough solution (as noted in the "out of scope" section). VirGL is a form of paravirtualization often called "API remoting".
Yes, llvmpipe or lavapipe is awesome. It is fully Vulkan 1.3 compliant and the performance is more than adequate for GUI apps, simple 3d apps or running your gfx tests in a CI environment without a GPU.
wow llvmpipe looks like what i need. I still need to figure a way to lie to some other bits that probe the hardware but this is going to be helpful
But thanks exDM69, zamadatix, fayalalebrun
Re: VirGL – A virtual 3D GPU for use inside QEMU virtual machines
#30VirGL is definitely an interesting project, but all one has to do to get GPU passthrough working (from a Linux QEMU host to any guest OS) is: 1.) research a cheap, secondary GPU that is natively supported by the guest OS, 2.) plug such a secondary GPU into a PCIe slot on the host and hook it up to the primary monitor with a secondary cable (D-Sub vs. DVI, etc.), 3.) setup Linux to ignore the secondary GPU at boot and…
> The whole process takes perhaps one or two hours and as works flawlessly, with no stability issues.
Good joke, that really made me laugh :)
I tried this on my ASRock X370 Taichi a while back. Turns out that there is a bug in older bios versions and the whole thing just freezes when starting the QEMU VM. Then there is an intermediate bios version with which I actually managed to get it working. Unforunately I later upgraded my CPU and had to install a new bios and this again completely breaks the IOMMU groups. Probably spend a few days to get everything running, including downgrading from a non-downgradeable bios version.
And even when it was working it was a pain to use. Want to use the passthrough GPU in Linux? Now I have to dual-boot QEMU VMs or disable the passthrough, reboot, then enable it again, reboot one more...
I really want proper GPU virtualisation...