openstack usb透传研究分析( centos7 )

1  The bus/device IDs can be obtained from virsh via the   'virsh nodedev-list --tree'   and   'virsh nodedev-dumpxml'   commands or using ' lsusb ' to determine the bus and device.

我采用的是lsusb来查看usb设备的编号，第一种方法，太麻烦了。

[root@nail-SBCJ-5-3-3 home]#   lsusb

Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub

Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Bus 002 Device 004: ID 0930:6544 Toshiba Corp. Kingston DataTraveler 2.0 Stick (2GB)

修改xml文件，填好字段   vendor:product(0930:6544 )

[root@nail-SBCJ-5-3-3 home]# cat usb.xml

        

            

            

        

      

或者修改xml文件，填好字段address

[root@nail-SBCJ-5-3-3 home]# cat usb1.xml

        

            

        

      

2  挂载usb设备

[root@Nail-SBCJ-slot5 home]# virsh attach-device instance-0000005d usb.xml

Device attached successfully

挂载成功后，虚拟机的xml里面会添加一段

 

     

       

       

       

     

     

   

虚拟机里面也会看到相应的u盘设备，如下在控制台里面，看到虚拟机识别到u盘为sdb，mount u盘分区后，可以看到u盘的内容。

3 u盘已经挂载成功之后，再尝试把u盘挂载到新的虚拟机，挂载失败

[root@Nail-SBCJ-slot5 home]#

[root@Nail-SBCJ-slot5 home]# virsh attach-device instance-00000061 usb.xml

error: Failed to attach device from usb.xml

error: Requested operation is not valid: USB device 002:004 is in use by domain instance-0000005d

You have new mail in /var/spool/mail/root

[root@Nail-SBCJ-slot5 home]# 

4  解挂载命令

[root@Nail-SBCJ-slot5 home]# virsh detach-device instance-0000005d usb.xml

Device detached successfully

  

  遇到的问题：

   1 lsusb命令不识别

      解决：安装   usbutils-007-4.el7.x86_64.rpm --nodeps

   2 有多个usb的时候，怎么判断虚拟机要哪个usb设备

     ？

   3 attach的时候，提示   'usb-host' is not a valid device model name

      解决：编译qemu的时候，带参数   --enable-libusb，并且编译好之后，要安装 rbd包

    From qemu-1.7 release version, the old usb-host(host-linux.c) had been removed,

    re-implemented by libusbx. So you should build qemu with --enable-libusb, then

    you can use usb pass-through capacity.

   4 如果usb分区成两个分区，不清楚对挂载有没有影响，需要进行测试验证，没有影响。

   5 u盘被一个虚拟机挂载之后，其他虚拟机不可以再挂载这个u盘

   

参考资料

https://ask.openstack.org/en/question/2612/feature-to-attach-usb-on-guest-vm/

http://rolandtapken.de/blog/2011-04/how-auto-hotplug-usb-devices-libvirt-vms-update-1

http://lists.gnu.org/archive/html/qemu-devel/2014-05/msg03629.html