Cannot recv data: Host key verification failed.: Connection reset by peer
This is a common error in WebVirtManager while using the ssh connection for quemu.
It can be solved by the following steps.
Step1: Login to the server via ssh as root.
Step2: Switch to nginx user as WebVirtManager use nginx user for authenticate on kvm.
#su -s /bin/bash nginx
Step3: Create ssh keys.
Step4: Copy the public key to root user.
Here we need to accept add key.