On 04/15/13 16:41, Anthony Liguori wrote: > Gerd Hoffmann <kra...@redhat.com> writes: > >> Hi, >> >>> When access a guest by console through VNC, there might be >>> mismatch between the lock keys notification LED on the computer >>> running the VNC client session and the current status of the lock >>> keys on the guest machine. This happens because the VNC protocol >>> does not have any support to deal with setting led state. >> >> What is the exact issue you are trying to fix here? >> >> The vnc server code in qemu already tracks the keyboard led state and >> will insert synthetic key events if needed to make sure vnc client and >> guest machine stay in sync. > > If the guest changes LED state, we want to the client to update the > physical keyboard LED state.
Guests usually change the LED state in response to a keyboard event, in which case the physical keyboard LEDs already have the correct state. There are exceptions of course. Guest linux kernel panic-ing, then blinking capslock. Multiple vnc clients connected at the same time. > Think thin client without an X server. Should be even less an issue there. With X & multiple windows guest+host capslock/numlock state go out of sync because of sequences like move-kbd-focus-away-from-vncclient-window + press-{caps,num}lock + move-focus-back (and thats why we have the logic to insert synthetic key events to resync in the first place). What is your vnc client? Does it support VNC_ENCODING_EXT_KEY_EVENT? cheers, Gerd