FYI, NVMeFix seems to have fixed the 'Loss of MMIO space' kernel panic for me. My SSD was working fine for a couple of years, but after upgrading to Monterey, I was getting almost daily crashes, especially when my Macbook Pro was sleeping overnight. Since installing NVMeFix, it's been up for 2 weeks now, knock on wood. My setup, for reference:
MacBookPro11,4 (Retina, 15-inch, Mid 2015)
Sabrent 2TB Rocket NVMe PCIe M.2 2280 Internal SSD
Sintech NGFF M.2 nVME SSD Adapter Card (Long)
The main difficulty I had was that it's not obvious how to install NVMeFix. Searching this forum had vague references to use Hackintool, so I downloaded it, but for the life of me, I couldn't figure out how to use it install NVMeFix. All I managed to do clicking around the various menu options was to get a NVMeFix.kext built in Hackintool_Kexts directory.
The Hackintool docs say 'Knowledge is required on how to patch before using it'.
The NVMeFix docs say 'NVMeFix requires at least Lilu 1.4.1'
The Lilu docs has prebuilt binaries, but no instruction on how to install it.
So here's how I got it to work, in case it'll help someone out.
1. Hackintool is for building and upgrading patches, after you patched it. So you need to patch the system first using Clover or OCLP.
2. For Monterey (basically Majave and later), you can't use Clover (default for Hackintool). You have to use OCLP.
3. Download OCLP from
https://github.com/dortania/OpenCore-Legacy-Patcher/releases
I use the TUI instead of GUI app, because I'd rather use the terminal than the GUI.
4. Make sure you back up your computer first. That said, I had no issues with my drive getting corrupted with OCLP.
5. When you run it, if you have a late model Mac like me, you would get an erro 'Your model is not supported by this patcher for running unsupported OSes!
Pick '5. Patcher Settings'
Pick '7. Allow OpenCore on native Models: Currently False'
Pick 'Allow OpenCore on all Models(y/n/q): ' y
Pick 'Q. Quit'
Pick '1. Build OpenCore'
You should see:
- Adding Lilu.kext 1.6.0
- Adding NVMeFix.kext 1.0.9
Pick '2. Install OpenCore to USB/internal drive'
Note: your disk number may be different, but it should be the only choice availble if you have no other drives (like USB) attached.
Pick '0. disk0: Sabrent (2.0 TB)'
Pick '1. disk0s1: EFI (209.7 MB) *'
Pick 'Q. Quit'
Reboot
6. Optional. If you want to disable the OCLP boot picker that shows you multiple drives to boot from on startup, so it automatically boots up to the apple logo like normal.
Pick '5. Patcher Settings'
Pick '5. Miscellaneous Settings'
Pick '1. Set ShowPicker Mode: Currently True'
Pick 'Show OpenCore Picker by default(y/n/q): ' n
and rebuild and install
That's it!