How to Enable Apple VTD on macOS

[kaoskinkae]

How to Enable Apple VTD on macOS

 

This guide covers the implementation of the Apple VTD function on macOS for Desktops and Laptops. By following this guide, you'll be able to enable VT-d on macOS using OpenCore Bootloader.

 

STEP 1: Enable VT-d in BIOS/UEFI

 

STEP 2: Configure Quirks

Disable “DisableMapper” Quirk kernel in the Quirks section.

 

STEP 3: SSDT-DMAR.aml

On a few systems (typically Desktops with less than 64GB and Laptops with less than 16GB of memory), when you enable VT-d which is required for some major functioning of a few particular devices such as Antelope Audio Interface and other Thunderbolt capable Devices, and a few Ethernet Cards, the system starts acting weird and all of a sudden, the network devices no longer work including Ethernet and WiFi. When checking the Devices in System Preferences>Network, the network adapters are in a loop, infinite link-up and link-down but never connect. In addition, the WiFi can be disrupted if you enable additional devices in BIOS (such as IGPU).

 

From OpenCore Documentation (“DisableMapper” section)

 

"Misconfigured IOMMU in the firmware may result in broken devices such as ethernet or Wi-Fi adapters. For instance, an ethernet adapter may cycle in link-up link-down state infinitely and a Wi-Fi adapter may fail to discover networks. Gigabyte is one of the most common OEMs with these issues."

 

Such issues were seen on systems running Big Sur and later. To overcome this issue, a user @yosoyoco came up with a fix and the idea was to fix the DMAR Table by removing the reserved memory regions from the native OEM DMAR Table, and then further dropping the OEM DMAR Table, and using the fixed DMAR Table, with the removed reserved regions. Although, this fix is required for the systems (mostly consumer Desktops and a fewer Laptops) running Big Sur and Later, a few users have reported such issues on Catalina and prior too.

 

SSDT-DMAR.aml, VT-d BIOS, Kernel Quiks Disable “DisableMapper· AppleVTD view en ioreg 

 

AppleVTD 

I225-V Ethernet ports on my mobo, and to get them working under Ventura 13.1 I had to enable Apple VTd

 

I recently saw that the creator of the network kext “RealtekRTL8111.kext” going to include in the new version available now in beta phase the AppleVTD which I really don't understand why, I think it will be an external or complementary card to an Intel one.

 

The question of this post is whether it would be interesting to have it active since in all the Intel systems tested the "DisableMapper" appears as active.

 

The information collected here is a copy and paste since I do not have a good command of English to create a post properly

 

Edited February 6 by kaoskinkae

[miliuco]

@kaoskinkae

It's DisableIoMapper. 
Note that there are systems that also need DisableIoMapperMapping, you can read about it here (credits to CaseySJ).

[kaoskinkae]

10 hours ago, miliuco said:

@kaoskinkae

Se trata de DisableIoMapper. 
Ten en cuenta que hay sistemas que también necesitan DisableIoMapperMapping. Puedes leer más sobre ello aquí  (créditos a CaseySJ).

Thanks for answering. I had already looked at this guide and some others but I had a question about this section.

Let's see if I can understand the whole topic and prepare a video on my channel in Spanish about the topic.

Edited February 7 by kaoskinkae