Grub file showing two GRD_CMDLINE_LINUX

I’m about to embark on the painful road of GPU passthrough
To start on this road, I need to hide my GPU from dom0
To do this, I need to add rd.qubes.hide_pci=[my GPU's device id] to GRD_CMDLINE_LINUX in the Grub file

sudo nano /etc/default/grub, and I have the Grub file
However…I have two GRD_CMDLINE_LINUX lines :confused:
The first has some rd. parameters, and the other starts with “sGRD_CMDLINE_LINUX …”

Before I mess up my machine: should I add rd.qubes.hide_pci to the first GRD_CMDLINE_LINUX, the second GRD_CMDLINE_LINUX, or is my system so weird that I need to follow different steps?

One of them simply concatenates another with more parameters

Something like:

GRUB_CMDLINE_LINUX="..."
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX ..."

Is vaguely similar to writing this in python:

a = "1"
a = a + "2"

You can add your stuff to any, or even add another entry just to keep it all tidy