Add kernel patch to resolve issue with GVT

[kcrawford]

Hi, I am facing an issue with PCI passthrough to a Windows VM that is resolved by building a custom kernel using the patch specified here: https://github.com/intel/gvt-linux/issues/153#issuecomment-1047603809

Rather than re-compile the kernel each time an update is made upstream, can this patch be added to the Proxmox kernel?

cc: @t.lamprecht

 

[t.lamprecht]

We normally do not take in random patches that suppress writes, it might be OK here, but such things can have serious side effects, possible limited to some other use cases or hardware.

Maybe ask the original author in a friendly way if they could please send their patch upstream to the Linux kernel, or if there's any reason why they didn't do so – as I did not find any existing submission for it.
Then we might get at least some feedback about potential impact and depending on that ship it in the Proxmox Kernel already earlier.

 

[kcrawford]

Thanks for the reply, the author of the patch stated that they are working with Intel to fix this on the driver side here: https://github.com/intel/gvt-linux/issues/153#issuecomment-1309030391 but efforts have been slow.

 

[t.lamprecht]

Ok, thanks for the pointer and good to hear about the author's effort.

For now, we still won't include this patch, carrying such patches is adding maintenance burden, especially if we do not review in-depth what the issue is and how this fix works – I'm afraid.