Would you pre-order Enhancer Software 2.3 to get Virtio-GPU ?

@n3m3
As I said I never tried 3D so don't know much about it but if I remember correctly there was a picture about AmigaOS 3D stuff somewhere (in one of sailor's articles on intuitionbase) that listed what libraries are related to what. I'd suggest to find that guide and picture about 3D on AmigaOS to try to make sense of the mess of libraries and drivers. I think there are multiple 3D APIs and different apps need different ones so may need to enable software rendering differently for those to use without a GPU. In any case you won't get hardware accelerated 3D on QEMU unless you use a passed through GPU or with virtio-gpu in the future if there will be a driver for that. You can run 3D apps but need software rendering enabled version. For Warp3D apps Wazp3D can do that, I have no idea on 3DNova or GLES or whatever else is there.

@n3m3

Sailor's excellent article about 3d. There is good pic how sw-parts are together. Real system with all ells and whistles. Somehow valid without gfx card, some parts drops away.

https://intuitionbase.com/articles/ami ... p-and-pcie-graphics-cards

@balaton


Thanks.

I expected that driver is general. Still qemu is pretty complicated software and it is sometimes difficult to understand, before see and use.

I even read some article about qemu and Virtio-GPU couple of days ago. Didnt get clear pic, if driver is on emulated machine or plugged to qemu on x64 side. So now I can make safe assumption, that it is Amiga driver, ppc.

No one probably cant say now, what will be emu penalty with single core cpu.

This is good thing indeed.

@Mlehto
Quote:
Have you read my summary on this link (also linked from https://qmiga.codeberg.page/#faq the last one about gfx emulation)? The virtio-gpu does not emulate any real GPU but is designed to efficiently communicate between guest and host to pass 3D operations from the guest (which needs a guest driver to talk to this device). Then on the host side these commands are passed on to a 3D renderer that uses the hosts's 3D API. As QEMU runs on the host as an application, it uses the host's drivers like any other app but the guest sees a virtio-gpu-pci card which it has to drive with its own driver but it does not need to know about the real GPU on the host.

Quote:
As the guest driver only passes the commands to the host and does not do any rendering it should be comparable to a passed through GPU or even faster if it avoids the limitations that we currently have with passed through GPUs. The amount of work to talk to a virtio-gpu is about the same as to drive a real GPU as it works quite similarly. The difference is that the commands are not executed by a dedicated real GPU but sent to the host so it can share the host's GPU with other apps and does not need a dedicated GPU or drivers for that GPU in the guest.

@n3m3

I digged some information to clear my head and made list for myself. It can have some errors but still some clarity what is what.

SM502
Datapath

Application -> AmigaOS -> SM502 driver -> QEMU device GTK/GL blit -> host GPU


Highest emulation overhead
Good compatibility, works everywhere



PCIe passtrough, IOMMU, Amiga native driver (Radeon HD/RX)

Datapath

Application -> AmigaOS -> HD/RX driver -> IOMMU -> host GPU

- Least emulation
-Good performance, near real thing probably, what other parts emulation cut down then.
-Cant do anything with graphics.library on-demand behaviour, short memory blocks from cpu -> gpu. Same as on real machine, though.


virtio-gpu

2D
Application -> AmigaOS -> virtio-gpu driver -> virtqueues -> QEMU virtio-gpu -> host GPU -> compositor

3D
Application -> AmigaOS -> virtio-gpu + virgl -> GL/VirGL commands via virtqueues -> virglrenderer -> host GL driver -> host GPU


-batched commands over virtqueue. At least possible that graphics.library chit-chatting with GPU is sended on larger chunks over DMA. Good.
-Emulation overhead higher than PCIe passtrought

Qemu supports OpenGL 4.6 / Linux Vulcan , any mesa on linux is valid for Amiga.

Cant comment Win/OSX as dont know them on that context.

@n3m3

Dbl post again…

@Mlehto
That's about right. For virtio the virtqueues are better than emulated cards because the emulated vCPU can write them without exiting emulation so it saves that overhead. The IOMMU with vfio-pci should allow the same but currently we have some overhead in that which makes accessing VRAM slower than it should be. I did not have time to try to find a solution and vfio was under development so it was changing so this won't be fixed in next QEMU release. Having to use 16bit with sm501 also causes a conversion to 32bit which makes that slower than it could be if the guest driver supported 32 or 24 bit. Therefore just getting a simple AmigaOS framebuffer driver that can use 24/32 bit could help a bit.