Re: [Qemu-devel] Windows vioinput guest driver tablet input bug

[Justin Gatzen]

The last email's diff got mangled due to long lines. The original
source has long lines still but it shouldnt get cut off his time.

Justin,


diff --git a/vioinput/sys/HidMouse.c b/vioinput/sys/HidMouse.c
index 69dac235..528bd3d6 100644
--- a/vioinput/sys/HidMouse.c
+++ b/vioinput/sys/HidMouse.c
@@ -325,7 +325,12 @@ HIDMouseProbe(
     DynamicArrayReserve(&AxisMap, AXIS_MAP_INITIAL_LENGTH * 2 * sizeof(ULONG));
 
     // Windows won't drive a mouse without at least the X and Y relative axes
-    if (InputCfgDataHasBit(pRelAxes, REL_X) && InputCfgDataHasBit(pRelAxes, 
REL_Y))
+    if (InputCfgDataHasBit(pRelAxes, REL_X) && InputCfgDataHasBit(pRelAxes, 
REL_Y)
+#ifdef EXPOSE_ABS_AXES_WITH_BUTTONS_AS_MOUSE
+        || (pMouseDesc->uNumOfButtons > 0 && InputCfgDataHasBit(pAbsAxes, 
ABS_X)
+            && InputCfgDataHasBit(pAbsAxes, ABS_Y))
+#endif // EXPOSE_ABS_AXES_WITH_BUTTONS_AS_MOUSE
+        )
     {
         for (i = 0; i < pRelAxes->size; i++)
         {
@@ -391,7 +396,8 @@ HIDMouseProbe(
     }
 
 #ifdef EXPOSE_ABS_AXES_WITH_BUTTONS_AS_MOUSE
-    if (uNumOfRelAxes == 0 &&
+    if ((!InputCfgDataHasBit(pRelAxes, REL_X) ||
+         !InputCfgDataHasBit(pRelAxes, REL_Y)) &&
         pMouseDesc->uNumOfButtons > 0 &&
         InputCfgDataHasBit(pAbsAxes, ABS_X) && InputCfgDataHasBit(pAbsAxes, 
ABS_Y))
     {


On Sun, Feb 25, 2018 at 05:21:29AM -0500, Justin Gatzen wrote:
> Hi,
> 
> The vioinput Windows guest driver does not seem to work with mouse wheel or
> side buttons for virtio-tablet-pci devices, while virtio-mouse-pci works as
> expected. Linux guest drivers are unaffected. Tablets are being categorized as
> mice due to the EXPOSE_ABS_AXES_WITH_BUTTONS_AS_MOUSE compile flag. But when
> there are no relative REL_X or REL_Y input axes the driver ignores all other
> relative axis entries. Mouse wheel is one such relative axis. I've attached a
> proof of concept fix for the guest driver that seems to fix both the mouse
> wheel and side buttons but I believe this needs a more robust fix and deeper
> look at the HIDMouseProbe function.
> 
> Thanks,
> Justin
> 
> 
> diff --git a/vioinput/sys/HidMouse.c b/vioinput/sys/HidMouse.c
> index 69dac235..ea188991 100644
> --- a/vioinput/sys/HidMouse.c
> +++ b/vioinput/sys/HidMouse.c
> @@ -325,7 +325,11 @@ HIDMouseProbe(
>      DynamicArrayReserve(&AxisMap, AXIS_MAP_INITIAL_LENGTH * 2 * 
> sizeof(ULONG));
> 
>      // Windows won't drive a mouse without at least the X and Y relative axes
> -    if (InputCfgDataHasBit(pRelAxes, REL_X) &&
> InputCfgDataHasBit(pRelAxes, REL_Y))
> +    if (InputCfgDataHasBit(pRelAxes, REL_X) &&
> InputCfgDataHasBit(pRelAxes, REL_Y)
> +#ifdef EXPOSE_ABS_AXES_WITH_BUTTONS_AS_MOUSE
> +        || (pMouseDesc->uNumOfButtons > 0 &&
> InputCfgDataHasBit(pAbsAxes, ABS_X) && InputCfgDataHasBit(pAbsAxes,
> ABS_Y))
> +#endif // EXPOSE_ABS_AXES_WITH_BUTTONS_AS_MOUSE
> +        )
>      {
>          for (i = 0; i < pRelAxes->size; i++)
>          {
> @@ -391,7 +395,7 @@ HIDMouseProbe(
>      }
> 
>  #ifdef EXPOSE_ABS_AXES_WITH_BUTTONS_AS_MOUSE
> -    if (uNumOfRelAxes == 0 &&
> +    if ((!InputCfgDataHasBit(pRelAxes, REL_X) ||
> !InputCfgDataHasBit(pRelAxes, REL_Y)) &&
>          pMouseDesc->uNumOfButtons > 0 &&
>          InputCfgDataHasBit(pAbsAxes, ABS_X) &&
> InputCfgDataHasBit(pAbsAxes, ABS_Y))
>      {