virtcontainers: Separate PCI/CCW for net devices

On s390x, virtio-net devices should use CCW, alongside a different
device path. Use accordingly.

Signed-off-by: Jakob Naucke <jakob.naucke@ibm.com>

src/runtime/virtcontainers/network.go

@@ -12,6 +12,7 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"runtime"
 
 	"github.com/sirupsen/logrus"
 	"github.com/vishvananda/netlink"
@@ -263,6 +264,15 @@ func generateVCNetworkStructures(ctx context.Context, endpoints []Endpoint) ([]*
 			ipAddresses = append(ipAddresses, &ipAddress)
 		}
 		noarp := endpoint.Properties().Iface.RawFlags & unix.IFF_NOARP
+		devicePath := endpoint.PciPath().String()
+		if runtime.GOARCH == "s390x" {
+			device := endpoint.CcwDevice()
+			if device == nil {
+				devicePath = ""
+			} else {
+				devicePath = device.String()
+			}
+		}
 		ifc := pbTypes.Interface{
 			IPAddresses: ipAddresses,
 			Device:      endpoint.Name(),
@@ -271,7 +281,7 @@ func generateVCNetworkStructures(ctx context.Context, endpoints []Endpoint) ([]*
 			Type:        string(endpoint.Type()),
 			RawFlags:    noarp,
 			HwAddr:      endpoint.HardwareAddr(),
-			DevicePath:  endpoint.PciPath().String(),
+			DevicePath:  devicePath,
 		}
 
 		ifaces = append(ifaces, &ifc)

src/runtime/virtcontainers/qemu.go

@@ -1942,16 +1942,7 @@ func (q *qemu) hotplugNetDevice(ctx context.Context, endpoint Endpoint, op Opera
 			}
 		}()
 
-		bridgeSlot, err := types.PciSlotFromInt(bridge.Addr)
-		if err != nil {
-			return err
-		}
-		devSlot, err := types.PciSlotFromString(addr)
-		if err != nil {
-			return err
-		}
-		pciPath, err := types.PciPathFromSlots(bridgeSlot, devSlot)
-		endpoint.SetPciPath(pciPath)
+		q.arch.setEndpointDevicePath(endpoint, bridge.Addr, addr)
 
 		var machine govmmQemu.Machine
 		machine, err = q.getQemuMachine()

src/runtime/virtcontainers/qemu_arch_base.go

@@ -116,6 +116,9 @@ type qemuArch interface {
 	// appendRNGDevice appends a RNG device to devices
 	appendRNGDevice(ctx context.Context, devices []govmmQemu.Device, rngDevice config.RNGDev) ([]govmmQemu.Device, error)
 
+	// setEndpointDevicePath sets the appropriate PCI or CCW device path for an endpoint
+	setEndpointDevicePath(endpoint Endpoint, bridgeAddr int, devAddr string) error
+
 	// addDeviceToBridge adds devices to the bus
 	addDeviceToBridge(ctx context.Context, ID string, t types.Type) (string, types.Bridge, error)
 
@@ -732,6 +735,23 @@ func (q *qemuArchBase) appendRNGDevice(_ context.Context, devices []govmmQemu.De
 	return devices, nil
 }
 
+func (q *qemuArchBase) setEndpointDevicePath(endpoint Endpoint, bridgeAddr int, devAddr string) error {
+	bridgeSlot, err := types.PciSlotFromInt(bridgeAddr)
+	if err != nil {
+		return err
+	}
+	devSlot, err := types.PciSlotFromString(devAddr)
+	if err != nil {
+		return err
+	}
+	pciPath, err := types.PciPathFromSlots(bridgeSlot, devSlot)
+	if err != nil {
+		return err
+	}
+	endpoint.SetPciPath(pciPath)
+	return nil
+}
+
 func (q *qemuArchBase) handleImagePath(config HypervisorConfig) error {
 	if config.ImagePath != "" {
 		kernelRootParams, err := GetKernelRootParams(config.RootfsType, q.disableNvdimm, false)

src/runtime/virtcontainers/qemu_s390x.go

@@ -304,6 +304,15 @@ func (q *qemuS390x) appendIOMMU(devices []govmmQemu.Device) ([]govmmQemu.Device,
 	return devices, fmt.Errorf("S390x does not support appending a vIOMMU")
 }
 
+func (q *qemuS390x) setEndpointDevicePath(endpoint Endpoint, bridgeAddr int, devAddr string) error {
+	ccwDev, err := types.CcwDeviceFrom(bridgeAddr, devAddr)
+	if err != nil {
+		return err
+	}
+	endpoint.SetCcwDevice(ccwDev)
+	return nil
+}
+
 func (q *qemuS390x) addDeviceToBridge(ctx context.Context, ID string, t types.Type) (string, types.Bridge, error) {
 	addr, b, err := genericAddDeviceToBridge(ctx, q.Bridges, ID, types.CCW)
 	if err != nil {