tests/functional: bail aarch64_virt tests early if missing TCG

The set_machine and require_accelerator steps can bail early so move
those to the front of the test functions. While we are at it also
clean up some long lines when adding the vm arguments.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20250108121054.1126164-23-alex.bennee@linaro.org>

tests/functional/test_aarch64_virt.py

@@ -40,9 +40,9 @@ def test_alpine_virt_tcg_gic_max(self):
         iso_path = self.ASSET_ALPINE_ISO.fetch()
 
         self.set_machine('virt')
-        self.vm.set_console()
         self.require_accelerator("tcg")
 
+        self.vm.set_console()
         self.vm.add_args("-accel", "tcg")
         self.vm.add_args("-cpu", "max,pauth-impdef=on")
         self.vm.add_args("-machine",
@@ -71,15 +71,16 @@ def common_aarch64_virt(self, machine):
         Common code to launch basic virt machine with kernel+initrd
         and a scratch disk.
         """
+        self.set_machine('virt')
+        self.require_accelerator("tcg")
+
         logger = logging.getLogger('aarch64_virt')
 
         kernel_path = self.ASSET_KERNEL.fetch()
 
-        self.set_machine('virt')
         self.vm.set_console()
         kernel_command_line = (self.KERNEL_COMMON_COMMAND_LINE +
                                'console=ttyAMA0')
-        self.require_accelerator("tcg")
         self.vm.add_args('-cpu', 'max,pauth-impdef=on',
                          '-machine', machine,
                          '-accel', 'tcg',
@@ -100,7 +101,9 @@ def common_aarch64_virt(self, machine):
 
         # Add the device
         self.vm.add_args('-blockdev',
-                         f"driver=qcow2,file.driver=file,file.filename={image_path},node-name=scratch")
+                         "driver=qcow2,"
+                         "file.driver=file,"
+                         f"file.filename={image_path},node-name=scratch")
         self.vm.add_args('-device',
                          'virtio-blk-device,drive=scratch')