From 34975e536f3531ad852d724a46280b882ec1bc9d Mon Sep 17 00:00:00 2001
From: Owen Smith <owen.smith@citrix.com>
Date: Fri, 3 Nov 2017 11:56:30 +0000
Subject: [PATCH] xenfb: Add [feature|request]-raw-pointer

Writes "feature-raw-pointer" during init to indicate the backend
can pass raw unscaled values for absolute axes to the frontend.
Frontends set "request-raw-pointer" to indicate the backend should
not attempt to scale absolute values to console size.
"request-raw-pointer" is only valid if "request-abs-pointer" is
also set. Raw unscaled pointer values are in the range [0, 0x7fff]

"feature-raw-pointer" and "request-raw-pointer" added to Xen
header in commit 7868654ff7fe5e4a2eeae2b277644fa884a5031e

Signed-off-by: Owen Smith <owen.smith@citrix.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
---
 hw/display/xenfb.c | 47 +++++++++++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 17 deletions(-)

diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c
index ed06efa21c..776a2ce559 100644
--- a/hw/display/xenfb.c
+++ b/hw/display/xenfb.c
@@ -52,6 +52,7 @@ struct common {
 struct XenInput {
     struct common c;
     int abs_pointer_wanted; /* Whether guest supports absolute pointer */
+    int raw_pointer_wanted; /* Whether guest supports raw (unscaled) pointer */
     QemuInputHandlerState *qkbd;
     QemuInputHandlerState *qmou;
     int axis[INPUT_AXIS__MAX];
@@ -264,24 +265,28 @@ static void xenfb_mouse_event(DeviceState *dev, QemuConsole *src,
 
     case INPUT_EVENT_KIND_ABS:
         move = evt->u.abs.data;
-        con = qemu_console_lookup_by_index(0);
-        if (!con) {
-            xen_pv_printf(&xenfb->c.xendev, 0, "No QEMU console available");
-            return;
+        if (xenfb->raw_pointer_wanted) {
+            xenfb->axis[move->axis] = move->value;
+        } else {
+            con = qemu_console_lookup_by_index(0);
+            if (!con) {
+                xen_pv_printf(&xenfb->c.xendev, 0, "No QEMU console available");
+                return;
+            }
+            surface = qemu_console_surface(con);
+            switch (move->axis) {
+            case INPUT_AXIS_X:
+                scale = surface_width(surface) - 1;
+                break;
+            case INPUT_AXIS_Y:
+                scale = surface_height(surface) - 1;
+                break;
+            default:
+                scale = 0x8000;
+                break;
+            }
+            xenfb->axis[move->axis] = move->value * scale / 0x7fff;
         }
-        surface = qemu_console_surface(con);
-        switch (move->axis) {
-        case INPUT_AXIS_X:
-            scale = surface_width(surface) - 1;
-            break;
-        case INPUT_AXIS_Y:
-            scale = surface_height(surface) - 1;
-            break;
-        default:
-            scale = 0x8000;
-            break;
-        }
-        xenfb->axis[move->axis] = move->value * scale / 0x7fff;
         break;
 
     case INPUT_EVENT_KIND_REL:
@@ -339,6 +344,7 @@ static QemuInputHandler xenfb_rel_mouse = {
 static int input_init(struct XenDevice *xendev)
 {
     xenstore_write_be_int(xendev, "feature-abs-pointer", 1);
+    xenstore_write_be_int(xendev, "feature-raw-pointer", 1);
     return 0;
 }
 
@@ -362,6 +368,13 @@ static void input_connected(struct XenDevice *xendev)
                              &in->abs_pointer_wanted) == -1) {
         in->abs_pointer_wanted = 0;
     }
+    if (xenstore_read_fe_int(xendev, "request-raw-pointer",
+                             &in->raw_pointer_wanted) == -1) {
+        in->raw_pointer_wanted = 0;
+    }
+    if (in->raw_pointer_wanted && in->abs_pointer_wanted == 0) {
+        xen_pv_printf(xendev, 0, "raw pointer set without abs pointer");
+    }
 
     if (in->qkbd) {
         qemu_input_handler_unregister(in->qkbd);