tests: Add an integration test to check duplicate PCI device IDs

This integration test verifies that the same device ID cannot be
allocated twice. Moreover, we check that the returned error matches our
expectations.

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

cloud-hypervisor/tests/integration.rs

@@ -5837,6 +5837,84 @@ mod common_parallel {
 
         handle_child_output(r, &output);
     }
+
+    #[test]
+    // Test that adding a duplicate PCI device ID fails
+    fn test_duplicate_pci_device_id() {
+        let disk_config = UbuntuDiskConfig::new(JAMMY_IMAGE_NAME.to_string());
+        let guest = Guest::new(Box::new(disk_config));
+
+        #[cfg(target_arch = "x86_64")]
+        let kernel_path = direct_kernel_boot_path();
+        #[cfg(target_arch = "aarch64")]
+        let kernel_path = edk2_path();
+
+        let api_socket = temp_api_path(&guest.tmp_dir);
+
+        // Boot without network
+        let mut cmd = GuestCommand::new(&guest);
+
+        cmd.args(["--api-socket", &api_socket])
+            .default_cpus()
+            .default_memory()
+            .args(["--kernel", kernel_path.to_str().unwrap()])
+            .args(["--cmdline", DIRECT_KERNEL_BOOT_CMDLINE])
+            .default_net()
+            .default_disks()
+            .capture_output();
+
+        let mut child = cmd.spawn().unwrap();
+
+        guest.wait_vm_boot().unwrap();
+
+        // Add a network device with non-static device ID request
+        let r = std::panic::catch_unwind(|| {
+            let (cmd_success, cmd_stdout, _) = remote_command_w_output(
+                &api_socket,
+                "add-net",
+                Some(
+                    format!(
+                        "id=test0,tap=,mac={},ip={},mask=255.255.255.128",
+                        guest.network.guest_mac1, guest.network.host_ip1,
+                    )
+                    .as_str(),
+                ),
+            );
+            assert!(cmd_success);
+
+            // We now know the first free device ID on the bus
+            let output = String::from_utf8(cmd_stdout).expect("should work");
+            let (_, _, first_free_device_id, _) = bdf_from_hotplug_response(output.as_str());
+            assert_ne!(first_free_device_id, 0);
+
+            let (cmd_success, _, cmd_stderr) = remote_command_w_output(
+                &api_socket,
+                "add-net",
+                Some(
+                    format!(
+                        "id=test1337,tap=,mac={},ip={},mask=255.255.255.128,pci_device_id={first_free_device_id}",
+                        guest.network.guest_mac1, guest.network.host_ip1,
+                    )
+                    .as_str(),
+                ),
+            );
+            // Check for fail; Allocating the same device ID for two devices is disallowed
+            assert!(!cmd_success);
+            // Check that the error message contains the expected error
+            let std_err_str = String::from_utf8(cmd_stderr).unwrap();
+            assert!(
+                std_err_str.contains(&format!(
+                    "Valid PCI device identifier but already used: {first_free_device_id}"
+                )),
+                "Command return was: {std_err_str}"
+            );
+        });
+
+        kill_child(&mut child);
+        let output = child.wait_with_output().unwrap();
+
+        handle_child_output(r, &output);
+    }
 }
 
 mod dbus_api {