> Hi, > > On 3/18/20 3:38 PM, Simon Ser wrote: > > Hi, > > > >> 1) Letting the VM-viewer window-system draw the cursor as it normally > >> would draw it. > > > > Why is this important? Can't the VM viewer hide the cursor and use a > > sub-surface to manually draw the cursor plane configured by the guest? > > Because then moving the cursor as seen by the user requires a round trip > through the VM and that adds latency, esp. when the VM viewer is viewing > a VM which is running somewhere else over the network. The video output has latency anyway. Using the host cursor will make the primary plane and cursor plane desynchronized. > Also note that a subsurface is a Wayland specific solution, where as > the VM-viewer may be running on X11, Windows, Mac OS, etc. I'm sure other window systems have similar solutions. You could always blend the cursor yourself. > > This would also allow the compositor running inside the VM to correctly > > have control over the cursor position, which is necessary for pointer > > constraints. > > Vms basically have 2 mouse modes: > > 1) Seamless, this works well for all apps which don't do weird things > with the cursor. This is what 99% of users want > > 2) Grab/confine the mouse on the first click inside the VM-viewer window > and constantly warp it to the center so that it can move "endlessly" > combined with drawing the VM's mouse cursor as a software sprite. > > Combined with a special key combo to release the cursor and allow it > to leave the VM window in case the user wants to interact with anything > else on their desktop. AKA the "this user experience sucks" mode which > sometimes is necessary for guests which don't support absolute input > coordinates, or for special use cases. > > Mode 2. can be used in case of apps inside the guest which want need > to constrain the pointer to stay inside a part-of the vm-viewer window, > note that the most prominent example of such apps are VM-viewer's > themselves and the whole purpose of seamless mode is to not need this > less then ideal user experience mode. If you don't care about synchronization and breaking pointer constraints in the guest, yes a new KMS plane property will be required. This sure sounds like abusing the KMS interface though. > Anyways as I mentioned in the p.s. to my original mail already, this > is exactly NOT the kind of feedback I'm looking for. Seamless mode > exists, it has done so for at least a decade, probably a lot longer. > > It works everywhere, across multiple platforms and hypervisors, > except with the KMS atomic API. The need to set hotspot coordinates > is not something which is up to discussion from my pov. What is up > for discussion is how to extend the KMS atomic API to allow this. That's not how it works. I'm sorry to say that, but I don't think asking a project to support a feature just because you want that feature is a good mind set. You'll need to convince people maintaining the project that adding the feature is a good idea whether you like it or not. A new feature is always up for discussion. Atomic KMS is missing the feature, and this can't be seen as a regression, because it never had the feature. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
