Chardev websocket might not support pasting more than a few chars
This bug has been copied automatically from: https://bugs.launchpad.net/qemu/+bug/1828608
Reported by 'Anisse Astier (anisse)' on 2019-05-10 :
When sending more than 4-5 characters on the websocket serial console (with pasting for example), the guest might not receive all of them, or worse interpret the input as Magic SysRq keys. This might be due to the io loop not checking the backend readiness before calling the read function. Attached patched fixes the problem on my system. I'm not sure it's the proper approach, this is just to start discussion.