gpu: Use a dedicated VFIO group vs iommufd entry

We do not want to abuse the sysfsentry lets use a dedicated
devfsentry.

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

src/runtime/pkg/device/config/config.go

@@ -396,6 +396,9 @@ type VFIODev struct {
 	// sysfsdev of VFIO mediated device
 	SysfsDev string
 
+	// DevfsDev is used to identify a VFIO Group device or IOMMMUFD VFIO device
+	DevfsDev string
+
 	// VendorID specifies vendor id
 	VendorID string
 

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

@@ -233,7 +233,8 @@ func GetDeviceFromVFIODev(device config.DeviceInfo) ([]*config.VFIODev, error) {
 		ID:       id,
 		Type:     vfioDeviceType,
 		BDF:      deviceBDF,
-		SysfsDev: device.HostPath,
+		SysfsDev: deviceSysfsDev,
+		DevfsDev: device.HostPath,
 		IsPCIe:   IsPCIeDevice(deviceBDF),
 		Class:    pciClass,
 		VendorID: vendorID,

src/runtime/pkg/govmm/qemu/qemu.go

@@ -1897,6 +1897,9 @@ type VFIODevice struct {
 
 	// SysfsDev specifies the sysfs matrix entry for the AP device
 	SysfsDev string
+
+	// DevfsDev is used to identify a VFIO Group device or IOMMMUFD VFIO device
+	DevfsDev string
 }
 
 // VFIODeviceTransport is a map of the vfio device name that corresponds to
@@ -1951,7 +1954,7 @@ func (vfioDev VFIODevice) QemuParams(config *Config) []string {
 		deviceParams = append(deviceParams, fmt.Sprintf("devno=%s", vfioDev.DevNo))
 	}
 
-	if strings.HasPrefix(vfioDev.SysfsDev, drivers.IommufdDevPath) {
+	if strings.HasPrefix(vfioDev.DevfsDev, drivers.IommufdDevPath) {
 		qemuParams = append(qemuParams, "-object")
 		qemuParams = append(qemuParams, fmt.Sprintf("iommufd,id=iommufd%s", vfioDev.ID))
 		deviceParams = append(deviceParams, fmt.Sprintf("iommufd=iommufd%s", vfioDev.ID))

src/runtime/virtcontainers/qemu_arch_base.go

@@ -714,6 +714,7 @@ func (q *qemuArchBase) appendVFIODevice(devices []govmmQemu.Device, vfioDev conf
 			DeviceID: vfioDev.DeviceID,
 			Bus:      vfioDev.Bus,
 			SysfsDev: vfioDev.SysfsDev,
+			DevfsDev: vfioDev.DevfsDev,
 		},
 	)