QEMU GPU vfio-pci pass through

@themamboman
You could set the bochs-display to full screen either with Ctrl-Alt-F or with a QEMU command line option so the mouse capture works on the full screen. As for the slowness it was found before but I don't know the reason. You run it with bboot which means the card's BIOS wasn't run so it was only init by the AtomBIOS parsed in the AmigaOS driver. This may be enough but it's possible the card needs to be init first by its BIOS so you could try using pegasos2.rom (then you still need bboot with bboot.fth to fix IRQs and 64bit BARs). Also look in Linux logs for vgaarb logs to make sure the passed through card's VGA ports are selected and not shadowed by some other card (this is what does not work with Intel integrated GPUs) because then the card's BIOS may not correctly run.
To debug the PCIE_CONFIG_SPACE_SIZE assert issue you could run QEMU under gdb (add gdb --args before the QEMU command then start in (gdb) with 'run') then you get a gdb prompt at the assert and can do backtrace to see where this was called. There a few places vfio calls this but I don't know how to fix that, you can try reporting at the QEMU mailing list or bug tracker with the QEMU command, backtrace and the error you get describing how you got the error.

@white
You may want the opposite, not using resizeable BAR with older RX card but make sure it's not using resizable BAR when passed through. One way to make sure is to disable it in BIOS but if your other card needs it this may not work. Consider that AmigaOS is 32 bit so can't access things above 4GB so you have to make sure the passed card can be mapped within the 4GB limit. That's why above 4GB decoding and resizeable BAR options may interfere. You could search for passing through GPUs to 32 bit (older) Windows guests, the problems may be similar with those than with AmigaOS. I don't know much about this so I can't help. I think getting an older RadeonHD card should be less problematic for pass through at first than getting the newest and biggest card AmigaOS can support but you can try it.

Why did you need UAE for AmiStore? Doesn't that run on AOS4 in QEMU too?

@balaton
Thanks for the advice.
Why did you need UAE for AmiStore? Doesn't that run on AOS4 in QEMU too ?

( I couldn't understand the question, sorry )



I accidentally found an answer from Asus three weeks ago

It would be nice in an upcoming BIOS update to enable full IOMMU group separation for B550-Plus mobo.

Asus moderator response:

We apologize for the delayed response due to a public holiday in our region and any inconvenience this may have caused.
We also appreciate your valuable feedback. Currently, the TUF GAMING B550-PLUS only supports the IOMMU setting.
I will forward your feedback to the relevant teams for further evaluation and consideration in future developments.



link Asus:
https://zentalk.asus.com/t5/motherboar ... -iommu-groups/td-p/463136

@white
Quote:
Sorry that was a question for @themamboman who mentioned this in post #58.

Also GPUs usually have two subdevices, one for the HDMI sound part. If these two are in one IOMMU group then you don't need other patches just pass both of them. You only may need kernel patch if your motherboard puts more slots in one IOMMU group but even in that case you can try plugging the card to be passed through in another slot to see if that has different IOMMU group with just the card in it. (If you only have two slots where the card fits then this may not be ideal.)

@white
The tests that did show the screen open were with the XFX RX 580. I have yet to get the Sapphire R9 270X to do anything other than reboot my computer when I launch qemu. It's on the latest firmware as well.

@balaton
I realized that I needed to get Enhancer and AmiStore had it less expensive and I was on my Windows side so I just launched AmigaOS4.1 in WinUAE since I had that set up.

I then copied the files out to USB, rebooted to Linux, copied them out, and rebuilt Kickstart.zip with them in place. Just a convenience thing.

Thanks for the suggestions on using pegasos2.rom. I'll try that next. I thought I had tried it and ran into an issue. I'll update. Thanks for all the help!

@balaton

Just tried using the bboot.fth script.

I had to use rdbtool to create a new disk image and copy over the files to the new drive in order to get the pegasos2.rom bios to see them: (modified slightly from your pegasos2 subpage



when it got to the point I could manually enter commands:



(Doing this without the vfio passthrough parts, and only using -device sm501, it booted okay (just no external graphics.

Switching by removing the sm501 and inserting the vfio devices:


I never get the opportunity to enter the boot command. Here is the output:

@themamboman

I didn't bother asking this question but what is the file
( bboot.fth script ) and where can it be found ?

Thanks