I found a solution to this problem, but I am unsure how bad of an idea this is. I would like your opinion.
To passthrough a disk, go to Show virtual hardware details in KVM, press Add Hardware and pick Storage. Then fill these in according to your setup.
To find your Serial, type sudo lshw. (apt install lshw if necessary) and find the appropriate device.
To find your device path, type ls /dev/disk/by-id/ and look for the appropriate device according to Serial.
This will let you access the drive as you would on your host.
I intend to never mount nor access this device on my host. What am I opening myself up to by doing this security wise?