解决步骤如下：
flashmx@ubuntu:~$ cvt 1920 1080 # 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync flashmx@ubuntu:~$ xrandr --newmode "1920X1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync flashmx@ubuntu:~$ xrandr --addmode Virtual1 "1920X1080_60.00" flashmx@ubuntu:~$ xrandr --output Virtual1 --mode "1920X1080_60.00"
If the last command doesn't work for you,you can go back to ubuntu display gui setting and can chose the display you have added just now.For me the option was 1904 x 1070 (16:9)
However if you are fine with this experiment and have found the desired screen resolution and to make that permanent,write the all the last 3 commands starting from xrandr --newmode command in your .xprofile file using following command and then save,exit and restart your ubuntu vm and you will get your desired resolution permanently.
$ gedit ~/.xprofile