From 83165225594ddda2ed2feadeff15c8621a0610ca Mon Sep 17 00:00:00 2001 From: jaminmc <1310376+jaminmc@users.noreply.github.com> Date: Tue, 17 Jun 2025 13:25:58 -0400 Subject: [PATCH] =?UTF-8?q?Added=20=E2=80=9CDisable=20above=204G=20decodin?= =?UTF-8?q?g=E2=80=9D=20to=20troubleshooting.?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With “above 4G decoding” enabled, the GPU passthrough functionality did not work for macOS, while it did work for Windows and Fedora. However, when disabling “above 4G decoding” in the BIOS, the GPU works for all three operating systems. --- README.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/README.md b/README.md index bab0410..471f7d1 100644 --- a/README.md +++ b/README.md @@ -133,6 +133,8 @@ If you encounter this error, you need to switch from **HTTPS** to **HTTP** in th ### ❌ Problem for GPU Passthrough +If you see an Apple logo and the bar doesn’t move on your external display, you need to disable “above 4g decoding” in the motherboard’s BIOS. + In some environments it is necessary to segment the IOMMU Groups to be able to pass the GPU to the VM. 1. Add the content `pcie_acs_override=downstream,multifunction pci=nommconf` in the file `/etc/default/grub` at the end of the line `GRUB_CMDLINE_LINUX_DEFAULT`;