Files
kata-containers/virtcontainers/device/drivers/vhost_user_net.go
Wei Zhang affd6e3216 devices: add reference count for devices.
Fixes #635

Remove `Hotplugged bool` field from device and add two new fields
instead:
* `RefCount`: how many references to this device. One device can be
referenced(`NewDevice()`) many times by same/different container(s),
two devices are regarded identical if they have same hostPath
* `AttachCount`: how many times this device has been attached. A device
can only be hotplugged once to the qemu, every new Attach command will
add the AttachCount, and real `Detach` will be done only when
`AttachCount == 0`

Signed-off-by: Wei Zhang <zhangwei555@huawei.com>
2018-08-31 09:53:01 +08:00

84 lines
2.0 KiB
Go

// Copyright (c) 2017-2018 Intel Corporation
// Copyright (c) 2018 Huawei Corporation
//
// SPDX-License-Identifier: Apache-2.0
//
package drivers
import (
"encoding/hex"
"github.com/kata-containers/runtime/virtcontainers/device/api"
"github.com/kata-containers/runtime/virtcontainers/device/config"
"github.com/kata-containers/runtime/virtcontainers/utils"
)
// VhostUserNetDevice is a network vhost-user based device
type VhostUserNetDevice struct {
*GenericDevice
config.VhostUserDeviceAttrs
}
//
// VhostUserNetDevice's implementation of the device interface:
//
// Attach is standard interface of api.Device, it's used to add device to some
// DeviceReceiver
func (device *VhostUserNetDevice) Attach(devReceiver api.DeviceReceiver) (err error) {
skip, err := device.bumpAttachCount(true)
if err != nil {
return err
}
if skip {
return nil
}
// generate a unique ID to be used for hypervisor commandline fields
randBytes, err := utils.GenerateRandomBytes(8)
if err != nil {
return err
}
id := hex.EncodeToString(randBytes)
device.DevID = id
device.Type = device.DeviceType()
defer func() {
if err == nil {
device.AttachCount = 1
}
}()
return devReceiver.AppendDevice(device)
}
// Detach is standard interface of api.Device, it's used to remove device from some
// DeviceReceiver
func (device *VhostUserNetDevice) Detach(devReceiver api.DeviceReceiver) error {
skip, err := device.bumpAttachCount(false)
if err != nil {
return err
}
if skip {
return nil
}
device.AttachCount = 0
return nil
}
// DeviceType is standard interface of api.Device, it returns device type
func (device *VhostUserNetDevice) DeviceType() config.DeviceType {
return config.VhostUserNet
}
// GetDeviceInfo returns device information used for creating
func (device *VhostUserNetDevice) GetDeviceInfo() interface{} {
device.Type = device.DeviceType()
return &device.VhostUserDeviceAttrs
}
// It should implement GetAttachCount() and DeviceID() as api.Device implementation
// here it shares function from *GenericDevice so we don't need duplicate codes