gpu: Add new struct PCIePort

For the hypervisor to distinguish between PCIe components, adding
a new enum that can be used for hot-plug and cold-plug of PCIe devices

Fixes: #6687

Signed-off-by: Zvonko Kaiser <zkaiser@nvidia.com>

src/runtime/pkg/hypervisors/hypervisor_state.go

@@ -26,6 +26,20 @@ type CPUDevice struct {
 	ID string
 }
 
+// PCIePort distinguish only between root and switch port
+type PCIePort string
+
+const (
+	// RootPort attach VFIO devices to a root-port
+	RootPort PCIePort = "root-port"
+	// SwitchPort attach VFIO devices to a switch-port
+	SwitchPort = "switch-port"
+	// BridgePort is the default
+	BridgePort = "bridge-port"
+	// NoPort is for disabling VFIO hotplug/coldplug
+	NoPort = "no-port"
+)
+
 type HypervisorState struct {
 	BlockIndexMap map[int]struct{}
 
@@ -45,6 +59,6 @@ type HypervisorState struct {
 	VirtiofsDaemonPid    int
 	Pid                  int
 	PCIeRootPort         int
-
+	ColdPlugVFIO         PCIePort
 	HotplugVFIOOnRootBus bool
 }