diff --git a/virttest/qemu_vm.py b/virttest/qemu_vm.py
index 0e976e2dfb..caee585ccb 100644
--- a/virttest/qemu_vm.py
+++ b/virttest/qemu_vm.py
@@ -740,11 +740,21 @@ def add_nic(
                     dev.parent_bus = pci_bus
                     dev.set_param("addr", pci_addr)
                 if nic_extra_params:
-                    nic_extra_params = (
-                        _.split("=", 1) for _ in nic_extra_params.split(",") if _
-                    )
+                    nic_extra_param_types = self.params.get("nic_extra_param_types", {})
+                    if nic_extra_param_types:
+                            nic_extra_param_types = dict(eval(nic_extra_param_types))
+                    nic_extra_params = (_.split('=', 1) for _ in
+                                        nic_extra_params.split(',') if _)
                     for key, val in nic_extra_params:
-                        dev.set_param(key, val)
+                        value_type = nic_extra_param_types.get(key)
+                        if value_type:
+                            try:
+                                converted_val = value_type(val)
+                                dev.set_param(key, converted_val)
+                            except ValueError as e:
+                                raise ValueError(f"Failed to convert {key}: {val} to {value_type}: {e}")
+                        else:
+                            dev.set_param(key, val)
                 dev.set_param("bootindex", bootindex)
                 if "aarch64" in params.get("vm_arch_name", arch.ARCH):
                     if "rombar" in devices.execute_qemu("-device %s,?" % model):