feat: Looking glass shm OOB auto generation and support (#424)

* feat: add support for default looking-glass shm file

* feat: add command to add selinux file context for looking-glass shm

* fix: add better description to the just command

* fix: correct vfio.pci.disable_vga=1 to vfio_pci.disable_vga=1

system_files/desktop/shared/usr/etc/tmpfiles.d/10-looking-glass.conf

@@ -0,0 +1,2 @@
+# Type Path               Mode UID  GID Age Argument
+f /dev/shm/looking-glass 0660 1000 qemu -

system_files/desktop/shared/usr/share/ublue-os/just/60-custom.just

@@ -292,7 +292,7 @@ enable-vfio:
         --append-if-missing="${VENDOR_KARG}" \
         --append-if-missing="iommu=pt" \
         --append-if-missing="rd.driver.pre=vfio_pci" \
-        --append-if-missing="vfio.pci.disable_vga=1"
+        --append-if-missing="vfio_pci.disable_vga=1"
       echo "VFIO enabled, make sure you enable IOMMU, VT-d or AMD-v in your BIOS!"
       echo "Please understand that since this is such a niche use case, support will be very limited!"
       echo "To add your unused/second GPU device ids to the vfio driver by running"
@@ -326,3 +326,7 @@ disable-watchdog:
     WATCHDOG_KARGS="$WATCHDOG_KARGS --append-if-missing=modprobe.blacklist=sp5100_tco"
   fi
   rpm-ostree kargs $WATCHDOG_KARGS
+
+# Add SELinux file context for default looking-glass shm file so that libvirt can create it when needed
+selinux-looking-glass:
+  sudo semanage fcontext -a -t svirt_tmpfs_t /dev/shm/looking-glass