gpu: Reset cold or hot plug after overriding

If we override the cold, hot plug with an annotation
we need to reset the other plugging mechanism to NoPort
otherwise both will be enabled.

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

src/runtime/pkg/device/drivers/vfio.go

@@ -71,8 +71,6 @@ func (device *VFIODevice) Attach(ctx context.Context, devReceiver api.DeviceRece
 	}
 	for _, vfio := range device.VfioDevs {
 		if vfio.IsPCIe {
-			//vfio.Rank = len(AllPCIeDevs)
-			//AllPCIeDevs[vfio.BDF] = true
 			busIndex := len(config.PCIeDevices[vfio.Port])
 			vfio.Bus = fmt.Sprintf("%s%d", config.PCIePortPrefixMapping[vfio.Port], busIndex)
 			config.PCIeDevices[vfio.Port][vfio.BDF] = true

src/runtime/pkg/oci/utils.go

@@ -592,11 +592,15 @@ func addHypervisorHotColdPlugVfioOverrides(ocispec specs.Spec, sbConfig *vc.Sand
 		if sbConfig.HypervisorConfig.HotPlugVFIO, err = addHypervisorPCIePortOverride(value); err != nil {
 			return err
 		}
+		// If hot-plug is specified disable cold-plug and vice versa
+		sbConfig.HypervisorConfig.ColdPlugVFIO = config.NoPort
 	}
 	if value, ok := ocispec.Annotations[vcAnnotations.ColdPlugVFIO]; ok {
 		if sbConfig.HypervisorConfig.ColdPlugVFIO, err = addHypervisorPCIePortOverride(value); err != nil {
 			return err
 		}
+		// If cold-plug is specified disable hot-plug and vice versa
+		sbConfig.HypervisorConfig.HotPlugVFIO = config.NoPort
 	}
 	return nil
 }

src/runtime/virtcontainers/qemu.go

@@ -65,6 +65,11 @@ const romFile = ""
 // Default value is false.
 const defaultDisableModern = false
 
+// A deeper PCIe topology than 5 is already not advisable just for the sake
+// of having enough buffer we limit ourselves to 10 and exit if we reach
+// the root bus
+const maxPCIeTopoDepth = 10
+
 type qmpChannel struct {
 	qmp     *govmmQemu.QMP
 	ctx     context.Context
@@ -1771,6 +1776,7 @@ func (q *qemu) qomGetPciPath(qemuID string) (types.PciPath, error) {
 	}
 	slots = append(slots, devSlot)
 
+	// This only works for Q35 and Virt
 	r, _ := regexp.Compile(`^/machine/.*/pcie.0`)
 
 	var parentPath = qemuID
@@ -1778,7 +1784,7 @@ func (q *qemu) qomGetPciPath(qemuID string) (types.PciPath, error) {
 	// than 5 is already not advisable just for the sake of having enough
 	// buffer we limit ourselves to 10 and leave the loop early if we hit
 	// the root bus.
-	for i := 1; i <= 10; i++ {
+	for i := 1; i <= maxPCIeTopoDepth; i++ {
 		parenBusQOM, err := q.qmpMonitorCh.qmp.ExecQomGet(q.qmpMonitorCh.ctx, parentPath, "parent_bus")
 		if err != nil {
 			return types.PciPath{}, err