Not able to passthrough RX480/580 anymore to Windows VM once passed thru to macOS


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Hello,

 

I am on unRAID 6.5.0 and use it for sometime without any big issue. Last week I followed @gridrunner's spaceinvader guide and set up the macOS high sierra virtual machines which work perfectly with my RX480/580 passthrough as well . After a couple of days I found out one problem, which is a bit annoying:

 

I am using the single GPU (Sapphire RX480/580 4GB) to passthru to all my VMs since I am not using them together. The cards works well both on Windows 10 VMs and macOS VMs.

However I do notice that as soon as the card has been passed thru to the macOS virtual machines once, I am not able to boot Windows virtual machines with the same card anymore (after shutting down macOS VM). The Windows VM just couldn't boot, and one CPU is looping with 100% usage all the time. Instead, it is not a problem to boot another macOS VM (after shutting down macOS VM) with the same graphic card. It seems like the macOS VM did something to the graphic card and it doesn't like Windows anymore...

 

The workaround is simple, I just need to reboot the unRAID. As I am the only user for the server so it is not a problem for me at this moment, just annoying.

 

Does anybody has the similar issue? I am thinking to get another  dedicate graphic card to macOS to resolve the issue if your guys have the same problem as well...

 

supplement:

macOS version: 10.13.3

 

Best Regards,

Alex

 

Edited by rowid_alex
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Hello I see others have issue in old release (6.2.4) that macOS is only able to boot once:

But this is not my case. I can boot other macOS VMs after shutting down macOS VM. The only issue is that I cannot boot any Windows VM anymore (with the same graphic card), unless I reboot the unRAID server... This should be related to the graphic cards, because it is totally not a problem if I don't passthru the GPU but use VNC to access macOS.

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Yesterday I made little progress with it. I added AppleALC and Lilu kext files into clover EFI partition, which fixed my RX480/580 recognition problem (previously R9 xxx, now RX580 4GB) and also the performance benchmark is back to normal. Now if I shut down the macOS and start up a Windows VM, there is no more one CPU looping 100% but looks more normal start up behavior, however, GPU still doesn't send the display any output yet.

I am feeling this is a kind of hackintosh problem instead of KVM itself...

Edited by rowid_alex
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3 hours ago, gridrunner said:

Make a Linux VM and try shutting that down then starting a window VM. Also, try passing through the vbios file see if that helps. Easy to do in 6.5 now. 

tried vbios file, which helps me to get the boot order screen before booting macOS, quite nice, but it doesn't resolve the problem for switching back to Windows.

uses the vbios file for Windows VM as well. Once used macOS then switch back to Windows VM. I can see the UEFI bios logo, then the screen output become a mess afterwards.

still have to reboot the machine to let the graphic card works again.

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1 hour ago, rowid_alex said:

tried vbios file, which helps me to get the boot order screen before booting macOS, quite nice, but it doesn't resolve the problem for switching back to Windows.

uses the vbios file for Windows VM as well. Once used macOS then switch back to Windows VM. I can see the UEFI bios logo, then the screen output become a mess afterwards.

still have to reboot the machine to let the graphic card works again.

6

There can be a problems with AMD GPU reinitialization sometimes, seems like the card isn't resetting correctly leaving the GPU in an initialized state when shutting down osx. Does the same happen if you shut down the windows VM then try and start the OSX VM? Or is it only when going from osx to windows?

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6 hours ago, gridrunner said:

There can be a problems with AMD GPU reinitialization sometimes, seems like the card isn't resetting correctly leaving the GPU in an initialized state when shutting down osx. Does the same happen if you shut down the windows VM then try and start the OSX VM? Or is it only when going from osx to windows?

When I switch from Windows VM to another Windows VM, it could happen, let's say once in ten times or 15 times.

 

When the issue happening, usually you just cannot boot the VM and of course you didn't see any output in the monitor as well. (if I use the vbios I might be able to see the UEFI BIOS logo, haven't tried it yet). The worst case, is that the fan of the graphic card is running to its max speed all the time, even after restart the unraid machine. I couldn't boot any VM as the card is not in the system device even. The only way to recover is to shutdown the tower and boot it up again. This occurs, not seldom, but also not often as well.

 

When I switch from Windows VM to macOS, just like switch from Windows to Windows above, usually it is fine. But there is no way to switch back to Windows VM anymore. With vbios I could see the UEFI BIOS logo then, the monitor starts to display some color blocks, very similar like if you overclocked too much for the GPU memory. Then the boot is stuck. However, it is totally not a problem, if I switch from macOS VM to another macOS VM or I start up the same macOS VM again.

 

 

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  • 1 month later...

So I upgraded from a GTX950 to an RX480 last week and saw this issue myself but not all the time. Just once, then I had to reboot and all was fine. Also seeing that after running the OSX VM for a few hours I sometimes get kernel grpahics errors and the entire VM will freeze for 5 seconds, be okay for 2 seconds, freeze for 5 seconds and so on. It's okay if I reboot the VM.

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