kvm ubuntu virturelization can,t enter display

1)ctrl + alt + f2 enter comand line

vi ~/.bashrc

export PATH=/usr/bin:$PATH

source ~/.bashrc

sudo reboot

2)

1,crtl + alt + f2

2, sudo apt-get install lightdm   ,chose lighdm whem need chose display style.

3,reboot;

4, if cna,t login  ,need also:

3)

•  ctrl+alt+f2 enter command line
•  su root，switch root user
• apt get remove gnome*
• reboot
• sudo apt install gnome*
• sudo apt get install gdm*
• sudo reboot