CI: Rework domU_config generation in qubes-x86-64.sh

Right now, various blocks rewrite domU_config= as a whole, even though it is
largely the same.

 * dom0pvh-hvm does nothing but change the domain type to hvm
 * *-pci sets the domain type, clears vif=[], appends earlyprintk=xen to the
   cmdline, and adds some PCI config.

Refactor this to be domU_type (defaults to pvh), domU_vif (defaults to
xenbr0), and domU_extra_config (defaults to empty) and use these variables to
build domU_config= once.

Of note, the default domU_config= now sets cmdline=, and extra= is intended
for inclusion via domU_extra_config as necessary.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
(cherry picked from commit 3be3ae0770)

automation/scripts/qubes-x86-64.sh

@@ -15,16 +15,9 @@ test_variant=$1
 extra_xen_opts=
 wait_and_wakeup=
 timeout=120
-domU_config='
-type = "pvh"
-name = "domU"
-kernel = "/boot/vmlinuz"
-ramdisk = "/boot/initrd-domU"
-extra = "root=/dev/ram0 console=hvc0"
-memory = 512
-vif = [ "bridge=xenbr0", ]
-disk = [ ]
-'
+domU_type="pvh"
+domU_vif="'bridge=xenbr0',"
+domU_extra_config=
 
 case "${test_variant}" in
     ### test: smoke test & smoke test PVH & smoke test HVM
@@ -50,16 +43,7 @@ echo \"${passed}\"
         fi
 
         if [ "${test_variant}" = "dom0pvh-hvm" ]; then
-            domU_config='
-type = "hvm"
-name = "domU"
-kernel = "/boot/vmlinuz"
-ramdisk = "/boot/initrd-domU"
-extra = "root=/dev/ram0 console=hvc0"
-memory = 512
-vif = [ "bridge=xenbr0", ]
-disk = [ ]
-'
+            domU_type="hvm"
         fi
         ;;
 
@@ -101,15 +85,11 @@ echo \"${passed}\"
 
         passed="pci test passed"
 
-        domU_config='
-type = "'${test_variant#pci-}'"
-name = "domU"
-kernel = "/boot/vmlinuz"
-ramdisk = "/boot/initrd-domU"
-extra = "root=/dev/ram0 console=hvc0 earlyprintk=xen"
-memory = 512
-vif = [ ]
-disk = [ ]
+        domU_type="${test_variant#pci-}"
+        domU_vif=""
+
+        domU_extra_config='
+extra = "earlyprintk=xen"
 pci = [ "'$PCIDEV',seize=1" ]
 on_reboot = "destroy"
 '
@@ -148,6 +128,18 @@ done
         ;;
 esac
 
+domU_config="
+type = '${domU_type}'
+name = 'domU'
+kernel = '/boot/vmlinuz'
+ramdisk = '/boot/initrd-domU'
+cmdline = 'root=/dev/ram0 console=hvc0'
+memory = 512
+vif = [ ${domU_vif} ]
+disk = [ ]
+${domU_extra_config}
+"
+
 # DomU
 mkdir -p rootfs
 cd rootfs