After my ubuntu upgrade, the keyboard and mouse won't work anymore.

After my ubuntu upgrade, the keyboard and mouse won't work anymore-general Linux technology-Linux technology and application information. The following is a detailed description. I used ubuntu10.04 and installed it on a virtual machine. A few days ago, I performed an upgrade. I chose all the items in the upgrade management. After the upgrade, everything went fine. However, when I start ubuntu again, the keyboard and mouse will not work after the login interface appears. Later, press ctrl + alt + F4 and F5 to jump out again. However, as long as you click the login interface again, it will fail again. I checked on the Internet and said that the configuration file was changed. I am a cainiao. I don't know how to deal with it. Some of them say that they want to change some files in linux, but my system cannot do this? Which of the following experts can give you some advice. Thank you ~~~~