Repro steps: $ sudo apt install qemu-system-x86 novnc /usr/share/novnc python3 -m http.server
Connect browser to http://<IP>:8000/vnc.html Click "Settings" Open "advanced" Open "websocket" Set port 5700 Clear path Click "Connect" And it works ... Turns out my former check on the offending noVNC commit was wrong. There are https://github.com/novnc/noVNC/commit/f8318361b1b62c4d76b091132d4a8ccfdd2957e4 (referenced on this bug before) $ git tag --contains f8318361b1b62c4d76b091132d4a8ccfdd2957e4 v1.0.0 But only really gone later with: https://github.com/novnc/noVNC/commit/c912230309806aacbae4295faf7ad6406da97617 $ git tag --contains c912230309806aacbae4295faf7ad6406da97617 v1.2.0 So the novnc of Focal isn't affected but anyone who uses a newer noVNC >=1.2 would be. => lower SRU priority => Modify above repro steps to not use noVNC from Focal via apt but use 1.2 from snaps Repro steps: $ snap install novnc $ novnc --vnc localhost:5700 Connect browser to http://<IP>:6080/vnc.html Click "Connect" TODO: repro steps to be verified with a qemu that has the fix applied ** Changed in: qemu (Ubuntu Focal) Importance: Undecided => Low -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1849644 Title: QEMU VNC websocket proxy requires non-standard 'binary' subprotocol Status in QEMU: Fix Released Status in qemu package in Ubuntu: Fix Released Status in qemu source package in Focal: Confirmed Bug description: When running a machine using "-vnc" and the "websocket" option QEMU seems to require the subprotocol called 'binary'. This subprotocol does not exist in the WebSocket specification. In fact it has never existed in the spec, in one of the very early drafts of WebSockets it was briefly mentioned but it never made it to a final version. When the WebSocket server requires a non-standard subprotocol any WebSocket client that works correctly won't be able to connect. One example of such a client is noVNC, it tells the server that it doesn't want to use any subprotocol. QEMU's WebSocket proxy doesn't let noVNC connect. If noVNC is modified to ask for 'binary' it will work, this is, however, incorrect behavior. Looking at the code in "io/channel-websock.c" it seems it's quite hard-coded to binary: Look at line 58 and 433 here: https://git.qemu.org/?p=qemu.git;a=blob;f=io/channel-websock.c This code has to be made more dynamic, and shouldn't require binary. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1849644/+subscriptions
