On 09.12.20 10:28, Michael S. Tsirkin wrote:

On Tue, Dec 08, 2020 at 11:01:50PM +0200, Vasyl Vavrychuk wrote:

quoted

From: Mathias Crombez <redacted>
Cc: stable@vger.kernel.org

I don't believe this is appropriate for stable, looks like
a new feature to me.

Agree, removed.

quoted

+config VIRTIO_INPUT_MULTITOUCH_SLOTS
+     depends on VIRTIO_INPUT
+     int "Number of multitouch slots"
+     range 0 64
+     default 10
+     help
+      Define the number of multitouch slots used. Default to 10.
+      This parameter is unused if there is no multitouch capability.
+
+      0 will disable the feature.
+

Most people won't be using this config so the defaults matter. So why 10? 10 fingers?

And where does 64 come from?

I have sent v3 version where number of slots it obtained from the host.

quoted

+     if (is_mt)
+             input_mt_init_slots(vi->idev,
+                                 CONFIG_VIRTIO_INPUT_MULTITOUCH_SLOTS,
+                                 INPUT_MT_DIRECT);

Do we need the number in config space maybe? And maybe with a feature
bit so host can find out whether guest supports MT?

I think it is not applicable in v3 which I sent, because number of slots 
is commit from the host. So, now host controls whether guest support MT.