Things are going pretty good after working through some of the issues others have learned from in this thread. I chose High Sierra because I'm a huge stoner I'm using an NVIDIA 1080ti for passthrough and it's compatible. The issues I'm having are:
I have two monitors, a Dell 144hz, 1440p w/ GSYNC over DP and a regular 1080p over HDMI. If I start the system with the Dell plugged in and turned on I get an offset apple logo and a tiny version of the display copied across the top of the monitor. However, it starts fine with only the 1080p monitor and will recognize the Dell once I'm booted into macOS (with GSYNC even! via the NVIDIA web driver)
Audio. I've passed through the NVIDIA 1080ti audio controller and the motherboard Intel C610/X99 series chipset HD audio controller but it's not working. the only thing I've done is download VooDooHDA.kext and put it in /System/Library/Extensions/ but I'm 99% sure that did nothing.
The version of High Sierra I'm on 10.13.6 (17G2208) doesn't want to automatically update to the last version of High Sierra, or manually update to the second to last version of High Sierra.
Also, what would happen to me GPU-wise if I tried to update to Mojave/Catalina through the App Store? would I retain any kind of NVIDIA support?
Anyway, here's my XML
<?xml version='1.0' encoding='UTF-8'?>
<domain type='kvm' id='16' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
<name>MacinaboxHighSierra</name>
<uuid>d98f9abf-cf2c-4d08-8699-475439c02ddd</uuid>
<description>MacOS High Sierra</description>
<metadata>
<vmtemplate xmlns="unraid" name="Windows 10" icon="default.png" os="HighSierra"/>
</metadata>
<memory unit='KiB'>16777216</memory>
<currentMemory unit='KiB'>16777216</currentMemory>
<memoryBacking>
<nosharepages/>
</memoryBacking>
<vcpu placement='static'>8</vcpu>
<cputune>
<vcpupin vcpu='0' cpuset='2'/>
<vcpupin vcpu='1' cpuset='8'/>
<vcpupin vcpu='2' cpuset='3'/>
<vcpupin vcpu='3' cpuset='9'/>
<vcpupin vcpu='4' cpuset='4'/>
<vcpupin vcpu='5' cpuset='10'/>
<vcpupin vcpu='6' cpuset='5'/>
<vcpupin vcpu='7' cpuset='11'/>
</cputune>
<resource>
<partition>/machine</partition>
</resource>
<os>
<type arch='x86_64' machine='pc-q35-3.1'>hvm</type>
<loader readonly='yes' type='pflash'>/mnt/user/domains/MacinaboxHighSierra/ovmf/OVMF_CODE.fd</loader>
<nvram>/mnt/user/domains/MacinaboxHighSierra/ovmf/OVMF_VARS.fd</nvram>
</os>
<features>
<acpi/>
<apic/>
</features>
<cpu mode='host-passthrough' check='none'>
<topology sockets='1' cores='4' threads='2'/>
</cpu>
<clock offset='utc'>
<timer name='rtc' tickpolicy='catchup'/>
<timer name='pit' tickpolicy='delay'/>
<timer name='hpet' present='no'/>
</clock>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<devices>
<emulator>/usr/local/sbin/qemu</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2' cache='writeback'/>
<source file='/mnt/user/domains/MacinaboxHighSierra/Clover.qcow2'/>
<backingStore/>
<target dev='hdc' bus='sata'/>
<boot order='1'/>
<alias name='sata0-0-2'/>
<address type='drive' controller='0' bus='0' target='0' unit='2'/>
</disk>
<disk type='file' device='disk'>
<driver name='qemu' type='raw' cache='writeback'/>
<source file='/mnt/user/domains/MacinaboxHighSierra/HighSierra-install.img'/>
<backingStore/>
<target dev='hdd' bus='sata'/>
<alias name='sata0-0-3'/>
<address type='drive' controller='0' bus='0' target='0' unit='3'/>
</disk>
<disk type='file' device='disk'>
<driver name='qemu' type='raw' cache='writeback'/>
<source file='/mnt/user/domains/MacinaboxHighSierra/macos_disk.img'/>
<backingStore/>
<target dev='hde' bus='sata'/>
<alias name='sata0-0-4'/>
<address type='drive' controller='0' bus='0' target='0' unit='4'/>
</disk>
<controller type='usb' index='0' model='ich9-ehci1'>
<alias name='usb'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x7'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci1'>
<alias name='usb'/>
<master startport='0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0' multifunction='on'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci2'>
<alias name='usb'/>
<master startport='2'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x1'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci3'>
<alias name='usb'/>
<master startport='4'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x2'/>
</controller>
<controller type='pci' index='0' model='pcie-root'>
<alias name='pcie.0'/>
</controller>
<controller type='pci' index='1' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='1' port='0x8'/>
<alias name='pci.1'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0' multifunction='on'/>
</controller>
<controller type='pci' index='2' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='2' port='0x9'/>
<alias name='pci.2'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
</controller>
<controller type='pci' index='3' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='3' port='0xa'/>
<alias name='pci.3'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
</controller>
<controller type='pci' index='4' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='4' port='0x13'/>
<alias name='pci.4'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x3'/>
</controller>
<controller type='pci' index='5' model='pcie-root-port'>
<model name='pcie-root-port'/>
<target chassis='5' port='0x14'/>
<alias name='pci.5'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x4'/>
</controller>
<controller type='virtio-serial' index='0'>
<alias name='virtio-serial0'/>
<address type='pci' domain='0x0000' bus='0x02' slot='0x00' function='0x0'/>
</controller>
<controller type='sata' index='0'>
<alias name='ide'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
</controller>
<interface type='bridge'>
<mac address='52:54:00:37:c4:2b'/>
<source bridge='br0'/>
<target dev='vnet0'/>
<model type='vmxnet3'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
</interface>
<serial type='pty'>
<source path='/dev/pts/0'/>
<target type='isa-serial' port='0'>
<model name='isa-serial'/>
</target>
<alias name='serial0'/>
</serial>
<console type='pty' tty='/dev/pts/0'>
<source path='/dev/pts/0'/>
<target type='serial' port='0'/>
<alias name='serial0'/>
</console>
<channel type='unix'>
<source mode='bind' path='/var/lib/libvirt/qemu/channel/target/domain-16-MacinaboxHighSierra/org.qemu.guest_agent.0'/>
<target type='virtio' name='org.qemu.guest_agent.0' state='disconnected'/>
<alias name='channel0'/>
<address type='virtio-serial' controller='0' bus='0' port='1'/>
</channel>
<input type='tablet' bus='usb'>
<alias name='input0'/>
<address type='usb' bus='0' port='1'/>
</input>
<input type='mouse' bus='ps2'>
<alias name='input1'/>
</input>
<input type='keyboard' bus='ps2'>
<alias name='input2'/>
</input>
<hostdev mode='subsystem' type='pci' managed='yes'>
<driver name='vfio'/>
<source>
<address domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
</source>
<alias name='hostdev0'/>
<rom file='/mnt/user/isos/GPU ROM/Gigabyte.GTX1080Ti.11264.170329.rom'/>
<address type='pci' domain='0x0000' bus='0x03' slot='0x00' function='0x0'/>
</hostdev>
<hostdev mode='subsystem' type='pci' managed='yes'>
<driver name='vfio'/>
<source>
<address domain='0x0000' bus='0x01' slot='0x00' function='0x1'/>
</source>
<alias name='hostdev1'/>
<address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x0'/>
</hostdev>
<hostdev mode='subsystem' type='pci' managed='yes'>
<driver name='vfio'/>
<source>
<address domain='0x0000' bus='0x00' slot='0x1b' function='0x0'/>
</source>
<alias name='hostdev2'/>
<address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x0'/>
</hostdev>
<hostdev mode='subsystem' type='usb' managed='no'>
<source>
<vendor id='0x046d'/>
<product id='0xc537'/>
<address bus='3' device='7'/>
</source>
<alias name='hostdev3'/>
<address type='usb' bus='0' port='2'/>
</hostdev>
<hostdev mode='subsystem' type='usb' managed='no'>
<source>
<vendor id='0x1532'/>
<product id='0x021e'/>
<address bus='3' device='35'/>
</source>
<alias name='hostdev4'/>
<address type='usb' bus='0' port='3'/>
</hostdev>
<memballoon model='none'/>
</devices>
<seclabel type='dynamic' model='dac' relabel='yes'>
<label>+0:+100</label>
<imagelabel>+0:+100</imagelabel>
</seclabel>
<qemu:commandline>
<qemu:arg value='-usb'/>
<qemu:arg value='-device'/>
<qemu:arg value='usb-mouse,bus=usb-bus.0'/>
<qemu:arg value='-device'/>
<qemu:arg value='usb-kbd,bus=usb-bus.0'/>
<qemu:arg value='-device'/>
<qemu:arg value='isa-applesmc,osk=s****************rk'/>
<qemu:arg value='-smbios'/>
<qemu:arg value='type=2'/>
<qemu:arg value='-cpu'/>
<qemu:arg value='Penryn,kvm=on,vendor=GenuineIntel,+invtsc,vmware-cpuid-freq=on,+pcid,+ssse3,+sse4.2,+popcnt,+avx,+aes,+xsave,+xsaveopt,check'/>
</qemu:commandline>
</domain>
macVM.xml