mjhjmtu

I am trying to set up a virtual machine with passthrough graphics. I am able to get the passthrough working for the UEFI shell, but not the Windows installer. I can get the Windows installer to work, but only with emulated graphics

This boots the windows installer in a QEMU Window:

sudo qemu-system-x86_64 --enable-kvm 
-name TESTVM,process=TESTVM 
-cdrom /media/big-tank-8TB/OSISOS/Windows/WindowsOct2018.iso 
-smp 4 
-cpu core2duo 
-m 4096 
-vga qxl

This also boots the windows installer in a QEMU window (still no passthrough)

sudo qemu-system-x86_64 --enable-kvm 
-name TESTVM,process=TESTVM 
-cdrom /media/big-tank-8TB/OSISOS/Windows/WindowsOct2018.iso 
-smp 4 
-cpu core2duo 
-m 4096 
-device vfio-pci,host=43:00.0,multifunction=on 
-device vfio-pci,host=43:00.1 

But if I specify the paths to UEFI firmware, I get the Tiano slpash screen and then the UEFI shell both on the monitor attached to my passed-through video card and in a QEMU window.

sudo qemu-system-x86_64 --enable-kvm 
-name TESTVM,process=TESTVM 
-cdrom /media/big-tank-8TB/OSISOS/Windows/WindowsOct2018.iso 
-smp 4 
-cpu core2duo 
-m 4096 
-device vfio-pci,host=43:00.0,multifunction=on 
-device vfio-pci,host=43:00.1 
-drive if=pflash,format=raw,readonly,file=/usr/share/OVMF/OVMF_CODE.fd 
-drive if=pflash,format=raw,file=/usr/share/OVMF/OVMF_VARS.fd 

Why is the passthrough working only in the absence of the UEFI files? Or, why is specifying the UEFI files preventing me from starting Windows?