conftest: split vm-type fixtures into require and skip variants

conftest.py

@@ -170,21 +170,26 @@ def pytest_collection_modifyitems(items: list[pytest.Item], config: pytest.Confi
     # Automatically mark tests based on fixtures they require.
     # Check pytest.ini or pytest --markers for marker descriptions.
 
-    markable_fixtures = [
-        'uefi_vm',
-        'unix_vm',
-        'windows_vm',
-        'hostA2',
-        'hostB1',
-        'unused_512B_disks',
-        'unused_4k_disks',
-    ]
+    # Maps fixture name -> mark name. skip_if_not_* variants map to the same mark as their
+    # fail counterparts since they still require the same VM type.
+    markable_fixtures: dict[str, str] = {
+        'uefi_vm': 'uefi_vm',
+        'skip_if_not_uefi_vm': 'uefi_vm',
+        'unix_vm': 'unix_vm',
+        'skip_if_not_unix_vm': 'unix_vm',
+        'windows_vm': 'windows_vm',
+        'skip_if_not_windows_vm': 'windows_vm',
+        'hostA2': 'hostA2',
+        'hostB1': 'hostB1',
+        'unused_512B_disks': 'unused_512B_disks',
+        'unused_4k_disks': 'unused_4k_disks',
+    }
 
     for item in items:
         fixturenames = getattr(item, 'fixturenames', ())
-        for fixturename in markable_fixtures:
+        for fixturename, markname in markable_fixtures.items():
             if fixturename in fixturenames:
-                item.add_marker(fixturename)
+                item.add_marker(markname)
 
         if 'vm_ref' not in fixturenames:
             item.add_marker('no_vm')
@@ -752,7 +757,16 @@ def running_vm(started_vm: VM) -> VM:
 def unix_vm(imported_vm: VM) -> Generator[VM, None, None]:
     vm = imported_vm
     if vm.is_windows:
-        pytest.skip("This test is only compatible with unix VMs.")
+        pytest.fail("This test requires a unix VM.")
+    yield vm
+
+@pytest.fixture(scope='module')
+def skip_if_not_unix_vm(imported_vm: VM) -> Generator[VM, None, None]:
+    # Skip (not fail) is intentional: used in multi-VM jobs where both unix and Windows VMs
+    # are present by design. A non-matching VM is expected, not a misconfiguration.
+    vm = imported_vm
+    if vm.is_windows:
+        pytest.skip("Skipping: this test is only compatible with unix VMs.")
     yield vm
 
 @pytest.fixture(scope="module")
@@ -764,14 +778,32 @@ def running_unix_vm(unix_vm: VM, running_vm: VM) -> VM:
 def windows_vm(imported_vm: VM) -> Generator[VM, None, None]:
     vm = imported_vm
     if not vm.is_windows:
-        pytest.skip("This test is only compatible with Windows VMs.")
+        pytest.fail("This test requires a Windows VM.")
+    yield vm
+
+@pytest.fixture(scope='module')
+def skip_if_not_windows_vm(imported_vm: VM) -> Generator[VM, None, None]:
+    # Skip (not fail) is intentional: used in multi-VM jobs where both unix and Windows VMs
+    # are present by design. A non-matching VM is expected, not a misconfiguration.
+    vm = imported_vm
+    if not vm.is_windows:
+        pytest.skip("Skipping: this test is only compatible with Windows VMs.")
     yield vm
 
 @pytest.fixture(scope='module')
 def uefi_vm(imported_vm: VM) -> Generator[VM, None, None]:
     vm = imported_vm
     if not vm.is_uefi:
-        pytest.skip('This test requires an UEFI VM')
+        pytest.fail('This test requires a UEFI VM.')
+    yield vm
+
+@pytest.fixture(scope='module')
+def skip_if_not_uefi_vm(imported_vm: VM) -> Generator[VM, None, None]:
+    # Skip (not fail) is intentional: used in multi-VM jobs where both UEFI and non-UEFI VMs
+    # are present by design. A non-matching VM is expected, not a misconfiguration.
+    vm = imported_vm
+    if not vm.is_uefi:
+        pytest.skip('Skipping: this test requires a UEFI VM.')
     yield vm
 
 @pytest.fixture(scope='session')

tests/guest_tools/unix/test_guest_tools_unix.py

@@ -26,7 +26,7 @@ def __init__(self) -> None:
 
 
 @pytest.mark.multi_vms
-@pytest.mark.usefixtures("unix_vm")
+@pytest.mark.usefixtures("skip_if_not_unix_vm")
 class TestGuestToolsUnix:
     @pytest.fixture(scope='class')
     def state(self) -> State:

tests/guest_tools/win/test_guest_tools_win.py

@@ -70,7 +70,7 @@
 
 
 @pytest.mark.multi_vms
-@pytest.mark.usefixtures("windows_vm")
+@pytest.mark.usefixtures("skip_if_not_windows_vm")
 class TestGuestToolsWindows:
     def test_drivers_detected(self, vm_install_test_tools_per_test_class: VM) -> None:
         pass
@@ -144,7 +144,7 @@ def test_xenvbd_ssd(self, vm_install_test_tools_per_test_class: VM) -> None:
 
 
 @pytest.mark.multi_vms
-@pytest.mark.usefixtures("windows_vm")
+@pytest.mark.usefixtures("skip_if_not_windows_vm")
 class TestGuestToolsWindowsDestructive:
     def test_uninstall_tools(self, vm_install_test_tools_no_reboot: VM) -> None:
         vm = vm_install_test_tools_no_reboot
@@ -176,7 +176,7 @@ def test_install_with_other_tools(
             exitcode = install_guest_tools(vm, guest_tools_iso, PowerAction.Nothing, check=False)
             assert exitcode == ERROR_INSTALL_FAILURE
 
-    @pytest.mark.usefixtures("uefi_vm")
+    @pytest.mark.usefixtures("skip_if_not_uefi_vm")
     def test_uefi_vm_suspend_refused_without_tools(self, running_unsealed_windows_vm: VM) -> None:
         vm = running_unsealed_windows_vm
         with pytest.raises(SSHCommandFailed, match="lacks the feature"):

tests/guest_tools/win/test_xenclean.py

@@ -94,7 +94,7 @@ def onboarding_guest_tools_iso(guest_tools_iso: Dict[str, Any]) -> Dict[str, Any
 
 
 @pytest.mark.multi_vms
-@pytest.mark.usefixtures("windows_vm")
+@pytest.mark.usefixtures("skip_if_not_windows_vm")
 class TestXenClean:
     def test_xenclean_without_tools(
         self, running_unsealed_windows_vm: VM, guest_tools_iso: Dict[str, Any]

tests/uefi_sb/test_uefistored_sb.py

@@ -38,7 +38,7 @@
 
 @pytest.mark.small_vm
 @pytest.mark.usefixtures("host_less_than_8_3")
-@pytest.mark.usefixtures("pool_without_uefi_certs", "unix_vm")
+@pytest.mark.usefixtures("pool_without_uefi_certs", "skip_if_not_unix_vm")
 class TestGuestLinuxUEFISecureBoot:
     PK: EFIAuth
     KEK: EFIAuth
@@ -135,7 +135,7 @@ def test_sb_off_really_means_off(self, uefi_vm: VM) -> None:
 
 
 @pytest.mark.usefixtures("host_less_than_8_3")
-@pytest.mark.usefixtures("pool_without_uefi_certs", "windows_vm")
+@pytest.mark.usefixtures("pool_without_uefi_certs", "skip_if_not_windows_vm")
 class TestGuestWindowsUEFISecureBoot:
     @pytest.fixture(autouse=True)
     def setup_and_cleanup(self, uefi_vm_and_snapshot: tuple[VM, Snapshot]) -> Generator[None, None, None]:

tests/uefi_sb/test_varstored_sb.py

@@ -37,7 +37,7 @@
 
 @pytest.mark.small_vm
 @pytest.mark.usefixtures("host_at_least_8_3")
-@pytest.mark.usefixtures("unix_vm")
+@pytest.mark.usefixtures("skip_if_not_unix_vm")
 class TestGuestLinuxUEFISecureBoot:
     PK: EFIAuth
     KEK: EFIAuth
@@ -137,7 +137,7 @@ def test_append_with_poison(self, uefi_vm: VM) -> None:
 
 
 @pytest.mark.usefixtures("host_at_least_8_3")
-@pytest.mark.usefixtures("windows_vm")
+@pytest.mark.usefixtures("skip_if_not_windows_vm")
 class TestGuestWindowsUEFISecureBoot:
     @pytest.fixture(autouse=True)
     def setup_and_cleanup(self, uefi_vm_and_snapshot: tuple[VM, Snapshot]) -> Generator[None, None, None]: