Changeset 77869 in vbox

Timestamp:

Mar 25, 2019 11:15:32 AM (6 years ago)

Author:

vboxsync

Message:

DevVGA-SVGA: report the mouse cursor position only if the guest actually updated it

File:

• trunk/src/VBox/Devices/Graphics/DevVGA-SVGA.cpp (modified) (7 diffs)

trunk/src/VBox/Devices/Graphics/DevVGA-SVGA.cpp

@@ -3335 +3335 @@
     uint32_t RT_UNTRUSTED_VOLATILE_GUEST * const pFIFO = pThis->svga.pFIFOR3;
     AssertReturnVoid(pThis->svga.pFIFOR3);
-    if (   vmsvgaFIFOHasWork(pFIFO, pThis->svga.uLastCursorUpdateCount)
+    if (   vmsvgaFIFOHasWork(pFIFO, ASMAtomicReadU32(&pThis->svga.uLastCursorUpdateCount))
         && pThis->svga.fFIFOThreadSleeping)
     {
@@ -3404 +3404 @@
     /*
      * Cursor update state (SVGA_FIFO_CAP_CURSOR_BYPASS_3).
-     * Initialize with values that will trigger an update as soon as maybe.
+     *
+     * Initialize with values that will detect an update from the guest.
+     * Make sure that if the guest never updates the cursor position, then the device does not report it.
+     * The guest has to change the value of uLastCursorUpdateCount, when the cursor position is actually updated.
+     * xLastCursor, yLastCursor and fLastCursorVisible are set to report the first update.
      */
     uint32_t RT_UNTRUSTED_VOLATILE_GUEST * const pFIFO = pThis->svga.pFIFOR3;
-    uint32_t uLastCursorCount   = pThis->svga.uLastCursorUpdateCount = ~pFIFO[SVGA_FIFO_CURSOR_COUNT];
+    pThis->svga.uLastCursorUpdateCount = pFIFO[SVGA_FIFO_CURSOR_COUNT];
     uint32_t xLastCursor        = ~pFIFO[SVGA_FIFO_CURSOR_X];
     uint32_t yLastCursor        = ~pFIFO[SVGA_FIFO_CURSOR_Y];
@@ -3432 +3436 @@
          */
         if (   fBadOrDisabledFifo
-            || !vmsvgaFIFOHasWork(pFIFO, uLastCursorCount))
+            || !vmsvgaFIFOHasWork(pFIFO, pThis->svga.uLastCursorUpdateCount))
         {
             ASMAtomicWriteBool(&pThis->svga.fFIFOThreadSleeping, true);
@@ -3445 +3449 @@
 # endif
                 if (   !fBadOrDisabledFifo
-                    && vmsvgaFIFOHasWork(pFIFO, uLastCursorCount))
+                    && vmsvgaFIFOHasWork(pFIFO, pThis->svga.uLastCursorUpdateCount))
                     rc = VINF_SUCCESS;
                 else
@@ -3467 +3471 @@
         if (rc == VERR_TIMEOUT)
         {
-            if (!vmsvgaFIFOHasWork(pFIFO, uLastCursorCount))
+            if (!vmsvgaFIFOHasWork(pFIFO, pThis->svga.uLastCursorUpdateCount))
             {
                 cMsSleep = RT_MIN(cMsSleep + cMsIncSleep, cMsMaxSleep);
@@ -3476 +3480 @@
             Log(("vmsvgaFIFOLoop: timeout\n"));
         }
-        else if (vmsvgaFIFOHasWork(pFIFO, uLastCursorCount))
+        else if (vmsvgaFIFOHasWork(pFIFO, pThis->svga.uLastCursorUpdateCount))
             STAM_REL_COUNTER_INC(&pSVGAState->StatFifoTodoWoken);
         cMsSleep = cMsMinSleep;
@@ -3544 +3548 @@
         {
             uint32_t const uCursorUpdateCount = pFIFO[SVGA_FIFO_CURSOR_COUNT];
-            if (uCursorUpdateCount == uLastCursorCount)
+            if (uCursorUpdateCount == pThis->svga.uLastCursorUpdateCount)
             { /* halfways likely */ }
             else
             {
-                uLastCursorCount = vmsvgaFIFOUpdateCursor(pThis, pSVGAState, pFIFO, offFifoMin, uCursorUpdateCount,
-                                                          &xLastCursor, &yLastCursor, &fLastCursorVisible);
+                uint32_t const uLastCursorCount = vmsvgaFIFOUpdateCursor(pThis, pSVGAState, pFIFO, offFifoMin, uCursorUpdateCount,
+                                                                         &xLastCursor, &yLastCursor, &fLastCursorVisible);
                 ASMAtomicWriteU32(&pThis->svga.uLastCursorUpdateCount, uLastCursorCount);
             }