testscript: Add tests for PCI BDF assignment

The added tests checks that libvirt and CHV assigned and propagate PCI
BDF correctly to the guest's PCI devices. It furthermore ensures, that
these assignment stay valid even after live migration.

Signed-off-by: Pascal Scholz <pascal.scholz@cyberus-technology.de>
On-behalf-of: SAP pascal.scholz@sap.com

Author: scholzp

tests/testscript.py

@@ -1246,10 +1246,141 @@ def test_live_migration_with_vcpu_pinning(self):
         assert int(taskset_vcpu0_controller, 16) == int(taskset_vcpu0_compute, 16)
         assert int(taskset_vcpu2_controller, 16) == int(taskset_vcpu2_compute, 16)
 
+    def test_bdf_implicit_assignment(self):
+        """
+        Test if all BDFs are correctly assigned in a scenario where some
+        are fixed in the XML and some are assigned by libvirt.
+
+        The domain XML we use here leaves a slot ID 0x03 free, but
+        allocates IDs 0x01, 0x02 and 0x04. 0x01 and 0x02 are dynamically
+        assigned by libvirt and not given in the domain XML. As 0x04 is
+        the first free ID, we expect this to be selected for the first
+        device we add to show that libvirt uses gaps. We add another
+        disk to show that all succeeding BDFs would be allocated
+        dynamically. Moreover, we show that all BDF assignments
+        survive live migration.
+        """
+
+        VIRTIO_NETWORK_DEVICE = "1af4:1041"
+        VIRTIO_BLOCK_DEVICE = "1af4:1042"
+        VIRTIO_ENTROPY_SOURCE = "1af4:1044"
+
+        controllerVM.succeed("virsh define /etc/domain-chv.xml")
+        controllerVM.succeed("virsh start testvm")
+        controllerVM.succeed("virsh attach-device testvm /etc/new_interface.xml")
+        assert wait_for_ssh(controllerVM)
+
+        # Add a disk that receive the first free BDF
+        controllerVM.succeed(
+            "qemu-img create -f raw /var/lib/libvirt/storage-pools/nfs-share/vdb.img 5M"
+        )
+        controllerVM.succeed(
+            "virsh attach-disk --domain testvm --target vdb --source /var/lib/libvirt/storage-pools/nfs-share/vdb.img"
+        )
+        controllerVM.succeed(
+            "qemu-img create -f raw /var/lib/libvirt/storage-pools/nfs-share/vdc.img 5M"
+        )
+        controllerVM.succeed(
+            "virsh attach-disk --domain testvm --target vdc --source /var/lib/libvirt/storage-pools/nfs-share/vdc.img"
+        )
+        devices = pci_devices_by_bdf(controllerVM)
+        # Implicitly added fixed to 0x01
+        assert devices["00:01.0"] == VIRTIO_ENTROPY_SOURCE
+        # Added by XML; dynamic BDF
+        assert devices["00:02.0"] == VIRTIO_BLOCK_DEVICE
+        # Added by this test
+        assert devices["00:03.0"] == VIRTIO_BLOCK_DEVICE
+        # Defined fixed BDF in XML
+        assert devices["00:04.0"] == VIRTIO_NETWORK_DEVICE
+        # Added by this test
+        assert devices["00:05.0"] == VIRTIO_BLOCK_DEVICE
+        # Defined in 1d to fill gab, no explicit BDF
+        assert devices["00:10.0"] == VIRTIO_NETWORK_DEVICE
+
+        # Check that we can reuse the same non-statically allocated BDF
+        controllerVM.wait_until_succeeds(
+            "virsh detach-disk --domain testvm --target vdb"
+        )
+        assert pci_devices_by_bdf(controllerVM).get("00:03.0") is None
+        controllerVM.succeed(
+            "virsh attach-disk --domain testvm --target vdb --source /var/lib/libvirt/storage-pools/nfs-share/vdb.img"
+        )
+        assert pci_devices_by_bdf(controllerVM).get("00:03.0") == VIRTIO_BLOCK_DEVICE
+
+        devices_before_livemig = pci_devices_by_bdf(controllerVM)
+        # Check that BDFs stay the same after migration
+        controllerVM.succeed(
+            "virsh migrate --domain testvm --desturi ch+tcp://computeVM/session --live --p2p"
+        )
+        assert wait_for_ssh(computeVM)
+        devices_after_livemig = pci_devices_by_bdf(computeVM)
+        assert devices_before_livemig == devices_after_livemig
+
+    def test_bdf_explicit_assignment(self):
+        """
+        Test if all BDFs are correctly assigned when binding them
+        explicitly to BDFs.
+
+        This test also shows that we can freely define the BDF that is
+        given to the RNG device. Moreover, we show that all BDF
+        assignments survive live migration, that allocating the same
+        BDF twice fails and that we can reuse BDFs if the respective
+        device was detached.
+        """
+        VIRTIO_NETWORK_DEVICE = "1af4:1041"
+        VIRTIO_BLOCK_DEVICE = "1af4:1042"
+        VIRTIO_ENTROPY_SOURCE = "1af4:1044"
+
+        controllerVM.succeed("virsh define /etc/domain-chv-static-bdf.xml")
+        controllerVM.succeed("virsh start testvm")
+        controllerVM.succeed("virsh attach-device testvm /etc/new_interface.xml")
+        controllerVM.succeed(
+            "virsh attach-disk --domain testvm --target vdb --source /var/lib/libvirt/storage-pools/nfs-share/cirros.img --address pci:0.0.17.0"
+        )
+
+        assert wait_for_ssh(controllerVM)
+
+        devices = pci_devices_by_bdf(controllerVM)
+        # Defined in 1a (entropy device is implicitly added by libvirt/CHV)
+        assert devices["00:01.0"] == VIRTIO_BLOCK_DEVICE
+        assert devices["00:04.0"] == VIRTIO_NETWORK_DEVICE
+        assert devices["00:05.0"] == VIRTIO_ENTROPY_SOURCE
+        assert devices["00:10.0"] == VIRTIO_NETWORK_DEVICE
+        assert devices["00:17.0"] == VIRTIO_BLOCK_DEVICE
+
+        # Check that BDF is freed and can be reallocated when de-/attaching a (entirely different) device
+        controllerVM.wait_until_succeeds(
+            "virsh detach-device testvm /etc/new_interface.xml"
+        )
+        controllerVM.wait_until_succeeds(
+            "virsh detach-disk --domain testvm --target vdb"
+        )
+        assert pci_devices_by_bdf(controllerVM).get("00:10.0") is None
+        assert pci_devices_by_bdf(controllerVM).get("00:17.0") is None
+        controllerVM.succeed(
+            "virsh attach-disk --domain testvm --target vdb --source /var/lib/libvirt/storage-pools/nfs-share/cirros.img --address pci:0.0.10.0"
+        )
+        devices_before_livemig = pci_devices_by_bdf(controllerVM)
+        assert devices_before_livemig.get("00:10.0") == VIRTIO_BLOCK_DEVICE
+
+        # Adding to the same bdf twice fails
+        controllerVM.wait_until_fails(
+            "virsh attach-device testvm /etc/new_interface.xml"
+        )
+
+        # Check that BDFs stay the same after migration
+        controllerVM.succeed(
+            "virsh migrate --domain testvm --desturi ch+tcp://computeVM/session --live --p2p"
+        )
+        assert wait_for_ssh(computeVM)
+        devices_after_livemig = pci_devices_by_bdf(computeVM)
+        assert devices_before_livemig == devices_after_livemig
+
 
 def suite():
     # Test cases in alphabetical order
     testcases = [
+        LibvirtTests.test_bdf_assignment,
         LibvirtTests.test_disk_is_locked,
         LibvirtTests.test_disk_resize_qcow2,
         LibvirtTests.test_disk_resize_raw,