x3sphere

Since the Big Sur update I'm no longer able to pass through a proper topology. Has anyone else encountered this? Setting cores / threads to 1 and changing sockets instead to 4 works, but this doesn't perform as well. If I set cores = 4 or threads to 1 or 2, for example, it just kernel panics on boot. Worked fine under Catalina and earlier though.

Nope, without a dedicated GPU attached to the VM I don't believe it is possible to get good performance out of macOS.

Here's my config: https://pastebin.com/ptt15R7K

Nested virtualization works here. Adding +hypervisor and +vmx flags got it working on an Intel CPU for me. Also using host-passthrough for CPU model, which I guess won't work with AMD CPU unless you apply patches. Without host-passthrough, the Android emulator was very slow. Even with this configuration it still is slow compared to native, but is usable.

Here is my XML config: https://pastebin.com/8F9atB2N I basically copied the OpenCore config verbatim from that git repo (https://github.com/Leoyzen/KVM-Opencore). Only change I made was to the serial numbers in the config.plist. Not loading any additional kext that aren't in that repo either. No, not my host. I was creating a copy of the VM without a GPU attached for testing purposes and it failed to boot. It seems like libvirt changes the buses around when you remove/add devices. For example, in the original config linked, the GPU I'm passing through is on bus 0x04. When I created a copy of the config and added a virtual VGA device, libvirt put it on bus 0x02 instead. For some reason that prevented macOS from booting properly. So I updated it to 0x04 to match my original config, and did the same for the NVMe drive. Then it booted fine. BTW, my 970 Evo isn't the Plus version, there seems to be a difference. Do you have the latest firmware? Seems even those with actual Mac hardware were getting kernel panics with this drive, see here: https://bartechtv.com/samsung-releases-new-firmware-for-970-evo-plus-that-resolves-macos-compatibility-issues/

No, never used that kext. What NVMe drive are you passing through? Mine is a Samsung 970 Evo. I can't say I've ever had any stability issues with the drive passed through. Usually I leave my VM running 24/7 and it's never crashed.

Strange. One difference is that I'm also passing through an NVMe drive (as the boot drive for the VM). Dunno if that would matter though. Good to know it works though. I was just comparing the libvirt XML config of the copied VM and it seems the "bus" value of the NVMe drive got changed when I removed the GPU. So maybe that is the problem... will try changing it back to the value in the other VM and see. Edit: It works now! I manually edited the config of the copied VM and updated the bus/slot variables for both the NVMe drive and virtual VGA device to match that of the original (which libvirt automatically changed when I was removing/adding the device). Now it boots fine.

I noticed, after passing through a GPU to macOS, I can no longer boot up the VM without an actual GPU attached. I created a copy of the VM, removed the GPU, and added the Spice display through virt-manager. On bootup it now hangs on "PCI configuration begin". If I add the GPU back, it boots fine then. Anyone else encounter this? I would like to have a copy of my VM that I can boot quickly without passing through a GPU, just for testing purposes. Using OpenCore with the config provided here https://github.com/Leoyzen/KVM-Opencore

Oh mine has that too - it's plugged into one of the USB headers on the mobo. I'm also passing through an entire USB controller from my mobo to the VM. I did try not passing through the USB controller and that didn't help though. Also passing through the USB controller without the card works fine. So it's just passing through the card itself that is causing issues for some reason...

The only kext I have installed is one for my Ethernet which I am also passing through. IntelMausiEthernet.kext. Removing that doesn't fix the issue though, it's isolated to the WiFi card. If I don't pass through the WiFi card, the system goes back to shutting down normally. I tried booting macOS in verbose mode to catch any errors on the shutdown process, or to see if it was hanging there, but doesn't seem to be - it goes to a full black screen and the monitor signal goes to off. I don't know if there's anything different I can try with how I'm attaching the PCI device to the VM that could fix it possibly.

No additional kext, this card just works out of the box in macOS.

Is anyone using a WiFi card with their macOS VM? I have this passed through: https://www.amazon.com/gp/product/B07VCCZS54/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 It's a BCM94360CD, so works OOB in macOS. Handoff and continuity features are working with it installed. My only issue is, the card prevents a clean shutdown of the VM. macOS appears to shut down fine but the VM hangs on "Shutting down" and there are no error messages in dmesg. Just wondering if anyone experienced the same and knew of a way of fix it. Not a huge deal, I can live with having to hard shut down the VM every so often but obviously this risks some corruption of the disk. Reboots work fine however.