diff -ur qtbase-opensource-src-5.2.0/src/plugins/platforms/xcb/qglxintegration.cpp qtbase-opensource-src-5.2.0-allow-forcing-llvmpipe/src/plugins/platforms/xcb/qglxintegration.cpp
--- qtbase-opensource-src-5.2.0/src/plugins/platforms/xcb/qglxintegration.cpp	2013-12-08 18:09:53.000000000 +0100
+++ qtbase-opensource-src-5.2.0-allow-forcing-llvmpipe/src/plugins/platforms/xcb/qglxintegration.cpp	2014-01-29 02:58:13.000000000 +0100
@@ -173,6 +173,27 @@
     if (m_format.renderableType() != QSurfaceFormat::OpenGL && m_format.renderableType() != QSurfaceFormat::OpenGLES)
         return;
 
+    // Allow forcing LIBGL_ALWAYS_SOFTWARE for Qt 5 applications only.
+    // This is most useful with drivers that only support OpenGL 1.
+    // We need OpenGL 2, but the user probably doesn't want
+    // LIBGL_ALWAYS_SOFTWARE in OpenGL 1 apps.
+    static bool checkedForceSoftwareOpenGL = false;
+    static bool forceSoftwareOpenGL = false;
+    if (!checkedForceSoftwareOpenGL) {
+        // If LIBGL_ALWAYS_SOFTWARE is already set, don't mess with it.
+        // We want to unset LIBGL_ALWAYS_SOFTWARE at the end so it does not
+        // get inherited by other processes, of course only if it wasn't
+        // already set before.
+        if (!qEnvironmentVariableIsEmpty("QT_XCB_FORCE_SOFTWARE_OPENGL")
+            && qEnvironmentVariableIsEmpty("LIBGL_ALWAYS_SOFTWARE"))
+            forceSoftwareOpenGL = true;
+
+        checkedForceSoftwareOpenGL = true;
+    }
+
+    if (forceSoftwareOpenGL)
+        qputenv("LIBGL_ALWAYS_SOFTWARE", "1");
+
     if (share)
         m_shareContext = static_cast<const QGLXContext*>(share)->glxContext();
 
@@ -267,8 +288,12 @@
         // Could not create a context using glXCreateContextAttribsARB, falling back to glXCreateNewContext.
         if (!m_context) {
             // requesting an OpenGL ES context requires glXCreateContextAttribsARB, so bail out
-            if (m_format.renderableType() == QSurfaceFormat::OpenGLES)
+            if (m_format.renderableType() == QSurfaceFormat::OpenGLES) {
+                // unset LIBGL_ALWAYS_SOFTWARE now so other processes don't inherit it
+                if (forceSoftwareOpenGL)
+                    qunsetenv("LIBGL_ALWAYS_SOFTWARE");
                 return;
+            }
 
             m_context = glXCreateNewContext(DISPLAY_FROM_XCB(screen), config, GLX_RGBA_TYPE, m_shareContext, true);
             if (!m_context && m_shareContext) {
@@ -287,8 +312,12 @@
         window = createDummyWindow(screen, config);
     } else {
         // requesting an OpenGL ES context requires glXCreateContextAttribsARB, so bail out
-        if (m_format.renderableType() == QSurfaceFormat::OpenGLES)
+        if (m_format.renderableType() == QSurfaceFormat::OpenGLES) {
+            // unset LIBGL_ALWAYS_SOFTWARE now so other processes don't inherit it
+            if (forceSoftwareOpenGL)
+                qunsetenv("LIBGL_ALWAYS_SOFTWARE");
             return;
+        }
 
         // Note that m_format gets updated with the used surface format
         visualInfo = qglx_findVisualInfo(DISPLAY_FROM_XCB(screen), screen->screenNumber(), &m_format);
@@ -317,6 +346,10 @@
 
     // Destroy our temporary window
     XDestroyWindow(DISPLAY_FROM_XCB(screen), window);
+
+    // unset LIBGL_ALWAYS_SOFTWARE now so other processes don't inherit it
+    if (forceSoftwareOpenGL)
+        qunsetenv("LIBGL_ALWAYS_SOFTWARE");
 }
 
 QGLXContext::~QGLXContext()