KVM Pass through disk Partition - By Label or UUID
If you look carefully at the disk symlinks in /dev/disk/by-id you will see that there are also links for each partition on the block devices. For instance:
ata-INTEL_SSDSC2BB480G7_PHDV644200N5480BGN
ata-INTEL_SSDSC2BB480G7_PHDV644200N5480BGN-part1
ata-INTEL_SSDSC2BB480G7_PHDV644200N5480BGN-part2
ata-INTEL_SSDSC2BB480G7_PHDV644200N5480BGN-part3
ata-INTEL_SSDSC2BB480G7_PHDV644200N5480BGN-part5
ata-INTEL_SSDSC2BB480G7_PHDV644200N5480BGN-part6
ata-INTEL_SSDSC2BB480G7_PHDV644200N5480BGN-part7
Use the one corresponding to your desired partition.