Copy&Paste does not work on VNC

Host environment

  • Operating system: Ubuntu 20.04
  • OS/kernel version: 5.4.0-91-generic
  • Architecture: x86 64-bit
  • QEMU flavor: qemu-system-x86_64
  • QEMU version: 6.2.92
  • QEMU command line: 
    .bin/bin/qemu-system-x86_64 ubuntu-desktop.qcow2 -m 2G -smp 2 -enable-kvm -vnc :0 -chardev qemu-vdagent,id=ch1,name=vdagent,clipboard=on -device virtio-serial-pci -device virtserialport,chardev=ch1,id=ch1,name=com.redhat.spice.0

Emulated/Virtualized environment

  • Operating system: Ubuntu 20.04
  • OS/kernel version: 5.11.0-41-generic
  • Architecture: x86 64 bit

Description of problem

Cannot copy&paste between host and guest when vnc is used (gtk works fine).

Steps to reproduce

  1. Build qemu 6.2-rc2 using the following ./configure options:
--prefix=$HOME/.bin --target-list=x86_64-softmmu --enable-kvm --enable-vnc --enable-gtk --enable-vte --enable-xkbcommon --enable-sdl --enable-spice --enable-spice-protocol --enable-virglrenderer --enable-opengl --enable-guest-agent --enable-avx2 --enable-hax --enable-system --enable-linux-user --enable-libssh --enable-linux-aio --enable-linux-io-uring --enable-modules --enable-fuse --enable-fuse-lseek
  1. Run the above qemu command using vnc server. Connect to the VM desktop using vncviewer :5900 where vncviewer is downloaded from here.
  2. Try to copy and paste something in the terminal between host and guest. It doesn't work.

Additional information

I'm following this article which says copy&paste is supported on vnc.