Hi On Mon, Jul 17, 2023 at 4:53 PM Gao,Shiyuan <gaoshiy...@baidu.com> wrote:
> > > > > > > > > So move the guest mouse pointer to (0, 0) of the screen when connect > the > > > > > VNC, and then move the mouse pointer to the cursor of VNC(absolute > > > > > coordinates are also relative coordinates). > > > > > > > > > > > > > > It's hardly a solution, you still have no clue what will be the guest > > > mouse > > > > position. > > > > > > We have no clue what will be the guest mouse position, we can move the > > > guest > > > mouse to (0,0) each connect the VNC. Now, the cursor of VNC will be the > > > relative coordinates. In a way, this is a quirk to know the guest mouse > > > position. > > > > > > > There is no guarantee the guest pointer will be at (0,0) though, and that > > doesn't explain how that would help. Which client are you using? Are you > > drawing the guest cursor? This can't be done currently with the lack of a > > message to tell the guest mouse position. (moving / sync-ing the client > > cursor position would be even worse in many ways) > > Sorry, my description isn't accurate. > > When connect the vnc server, > vnc_connect > -> vs->last_x = -1; > -> vs->last_y = -1; > > move client cursor to vnc screen, > vnc_client_io > ->vnc_client_read > ->protocol_client_msg > ->pointer_event(x,y) > -> qemu_input_queue_rel(con, INPUT_AXIS_X, 0 - width); > -> qemu_input_queue_rel(con, INPUT_AXIS_Y, 0 - height); > -> x=0,y=0 > -> vs->last_x = x;vs->last_y = y; > -> qemu_input_event_sync // this will inform the guest move > to (0, 0) > > the next event, > ->pointer_event(x,y) > -> qemu_input_queue_rel(con, INPUT_AXIS_X, x - vs->last_x); > -> qemu_input_queue_rel(con, INPUT_AXIS_X, x - vs->last_x); > -> qemu_input_event_sync // this will inform the guest from > (0,0) move to (x,y), > // the > client cursor and guest mouse will sync. > Actually, it will be ( x - vs->last_x, y - vs->last_y), not necessarily (x, y), unless you also set last_x = 0 / last_y = 0. But even then, there is no guarantee the guest position will be a x/y... > and if the resolution is high, alse need increace the queue size of ps2 > PS2_QUEUE_SIZE. > Otherwise, if the guest mouse far from the (0,0) before vnc connect, it > can't move to (0,0). > > Oh indeed, ps2 will queue multiple messages.. another reason you can't do such big relative moves reliably. > > > > > > > > > > > > > > > On windows VM, also need disable "Enhance Pointer Precision" > Option in > > > > > "Pointer Options" (Control Panel -> Mouse). > > > > > > > > > > > > > > Apparently, this option doesn't have much to do with relative mouse > > > motion. > > > > Can you explain what it does with this change? > > > > > > Emmm, I don't know why this can solve the problem. It's quite > effective and > > > get this way from > > > > > > > https://forum.proxmox.com/threads/is-it-possible-not-to-use-usbdevice-tablet.1498/ > > > . > > > > > > Only use this way, we need to manually align the VNC cursor with the > guest > > > mouse. > > > > > > > It's a bit vague what the "VNC cursor" mean. If you mean the client > cursor > > position, there is no way to align / sync with the guest without an extra > > message to inform the client of its position. There is even a comment > about > > that in vnc.c /* can we ask the client(s) to move the pointer ??? */) > > Sorry, I mean the client cursor position. I found disable "Enhance Pointer > Precision" > Option, move cursor to the bound of the VNC screen, they maybe align. > > > > > > > > > > > > > Which guest OS are you using? Hopefully they all support either > > > usb-tablet > > > > or vmmouse extension for absolute positioning. Otherwise, I'd suggest > > > using > > > > Spice, which has those messages for client side guest-mouse drawing. > > > > > > > > > > Yeah, I know the best way is use a absolute positioning. We need remove > > > all usb devices, > > > I can only use the PS/2 mouse. > > > > > > > Can't you use vmmouse extension? > > Thanks, I will try it. I cann't found the official driver of vmmouse, can I > install it for free? > > It's been implemented on Linux VM for a long while (first in userspace, then in kernel since ~2015). But I don't know about the Windows support, it looks like you need a driver such as provided by VMWave, but it seems closed-source... At this point it's probably better to use virtio-input, which has open-source/free windows drivers.
