VNC Not Responsive When Using VNC to Access a KVM

Symptom

After installing CentOS 7.6 on Kunpeng severs and applying the KVM virtualization solution, a user uses VNC to log in to the created VM, but VNC is not responsive.

Details are as follows: After logging in to a VM using VNC, the user cannot enter any character and the GUI does not respond.

Key Process and Cause Analysis

View the environment information.

virsh list --all

The following information is displayed, indicating that the name of the faulty VM is centos.

 Id   Name         State
----------------------------
 16   test1-name   running
 19   centos       running

Check the configuration of the VM centos.
```
virsh edit centos
```
The following figure shows that only the mouse is defined in the VM configuration file, and the VM uses the mouse connected to the PS2 bus as the input device. On Arm servers, VMs do not support the PS2 bus–connected mouse as the input device.

Conclusion and Solution

On Arm servers, VMs do not support the PS2 bus–connected mouse as the input device. Change the mouse connection to VirtIO. In this case, the faulty VM centos is used as an example.

Stop the VM.
```
virsh shutdown centos
```
Change the mouse connection to VirtIO, add the keyboard configuration, and configure the keyboard to be connected through the VirtIO bus.
1. Run the following command to modify the VM configuration:
```
virsh edit centos
```
2. Press i to enter the insert mode and modify the <input tye='mouse' bus='ps2'/> field as follows:
```
<input type-'mouse' bus='virtio'/>
<input type='keyboard' bus= virtio'/>
```
3. Press Esc to exit the insert mode. Type :wq! and press Enter to save the file and exit.
Restart the VM.
```
virsh start centos
```
After the VM is started, check the current VM configuration.
```
virsh dumpxml centos
```
As the figure shows, the VM configuration has taken effect.
Log in to the VM using VNC again. The VM is normal.

Parent topic: KVM Virtualization