diff --git a/src/Makefile.am b/src/Makefile.am
index 9b668c8..d470747 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -35,6 +35,8 @@ libvrend_la_SOURCES = \
         vrend_blitter.c \
         vrend_blitter.h \
         vrend_strbuf.h \
+        vrend_tweaks.c \
+        vrend_tweaks.h \
         iov.c
 
 if HAVE_EPOXY_EGL
diff --git a/src/virgl_protocol.h b/src/virgl_protocol.h
index ac8bfba..107076a 100644
--- a/src/virgl_protocol.h
+++ b/src/virgl_protocol.h
@@ -592,4 +592,8 @@ enum virgl_context_cmd {
 #define VIRGL_COPY_TRANSFER3D_SRC_RES_OFFSET 13
 #define VIRGL_COPY_TRANSFER3D_SYNCHRONIZED 14
 
-#endif
+enum vrend_tweak_type {
+   virgl_tweak_undefined
+};
+
+#endif
\ No newline at end of file
diff --git a/src/vrend_renderer.c b/src/vrend_renderer.c
index 3f950f3..5d8f68f 100644
--- a/src/vrend_renderer.c
+++ b/src/vrend_renderer.c
@@ -593,6 +593,7 @@ struct vrend_sub_context {
 
    struct vrend_abo abo[PIPE_MAX_HW_ATOMIC_BUFFERS];
    uint32_t abo_used_mask;
+   struct vrend_context_tweaks tweaks;
 };
 
 struct vrend_context {
@@ -667,6 +668,11 @@ static inline bool vrend_format_is_ds(enum virgl_formats format)
    return tex_conv_table[format].bindings & VIRGL_BIND_DEPTH_STENCIL;
 }
 
+struct vrend_context_tweaks *vrend_get_context_tweaks(struct vrend_context *ctx)
+{
+   return &ctx->sub->tweaks;
+}
+
 bool vrend_format_is_emulated_alpha(enum virgl_formats format)
 {
    if (vrend_state.use_gles || !vrend_state.use_core_profile)
diff --git a/src/vrend_renderer.h b/src/vrend_renderer.h
index 5fe540f..7d92427 100644
--- a/src/vrend_renderer.h
+++ b/src/vrend_renderer.h
@@ -395,6 +395,8 @@ void vrend_renderer_get_rect(int resource_id, struct iovec *iov, unsigned int nu
 void vrend_renderer_attach_res_ctx(int ctx_id, int resource_id);
 void vrend_renderer_detach_res_ctx(int ctx_id, int resource_id);
 
+struct vrend_context_tweaks *vrend_get_context_tweaks(struct vrend_context *ctx);
+
 struct vrend_renderer_resource_info {
    uint32_t handle;
    uint32_t format;
diff --git a/src/vrend_tweaks.c b/src/vrend_tweaks.c
new file mode 100644
index 0000000..244010b
--- /dev/null
+++ b/src/vrend_tweaks.c
@@ -0,0 +1,75 @@
+/**************************************************************************
+ *
+ * Copyright (C) 2018 Collabora Ltd
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+#include <string.h>
+#include <stdlib.h>
+#include "vrend_tweaks.h"
+#include "vrend_debug.h"
+#include "virgl_protocol.h"
+
+inline static void get_tf3_samples_passed_factor(struct vrend_context_tweaks *ctx, void *params)
+{
+   *(uint32_t *)params =  ctx->tf3_samples_passed_factor;
+}
+
+bool vrend_get_tweak_is_active_with_params(struct vrend_context_tweaks *ctx, enum vrend_tweak_type t, void *params)
+{
+   if (!(ctx->active_tweaks & (1u << t)))
+      return false;
+
+   return true;
+}
+
+bool vrend_get_tweak_is_active(struct vrend_context_tweaks *ctx, enum vrend_tweak_type t)
+{
+   return (ctx->active_tweaks & (1u << t)) ? true : false;
+}
+
+const char *tweak_debug_table[] = {
+   [virgl_tweak_undefined] = "Undefined tweak"
+};
+
+static void set_tweak_and_params(struct vrend_context_tweaks *ctx,
+                                 enum vrend_tweak_type t, uint32_t value)
+{
+   ctx->active_tweaks |= 1u << t;
+}
+
+static void set_tweak_and_params_from_string(struct vrend_context_tweaks *ctx,
+                                             enum vrend_tweak_type t, const char *value)
+{
+   ctx->active_tweaks |= 1u << t;
+   (void)value;
+}
+
+/* we expect a string like tweak1:value,tweak2:value */
+void vrend_set_active_tweaks(struct vrend_context_tweaks *ctx, uint32_t tweak_id, uint32_t value)
+{
+   if (tweak_id < virgl_tweak_undefined) {
+      VREND_DEBUG(dbg_tweak, NULL, "Apply tweak '%s' = %u\n", tweak_debug_table[tweak_id], value);
+      set_tweak_and_params(ctx, tweak_id, value);
+   } else {
+      VREND_DEBUG(dbg_tweak, NULL, "Unknown tweak %d = %d sent\n", tweak_id, value);
+   }
+}
diff --git a/src/vrend_tweaks.h b/src/vrend_tweaks.h
new file mode 100644
index 0000000..f3aee29
--- /dev/null
+++ b/src/vrend_tweaks.h
@@ -0,0 +1,49 @@
+/**************************************************************************
+ *
+ * Copyright (C) 2018 Collabora Ltd
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+#ifndef VREND_TWEAKS_H
+#define VREND_TWEAKS_H
+
+#include "virgl_protocol.h"
+
+#include <stdint.h>
+#include <stdbool.h>
+
+struct vrend_context_tweaks {
+   uint32_t active_tweaks;
+   int32_t tf3_samples_passed_factor;
+};
+
+bool vrend_get_tweak_is_active(struct vrend_context_tweaks *ctx,
+                               enum vrend_tweak_type t);
+
+bool vrend_get_tweak_is_active_with_params(struct vrend_context_tweaks *ctx,
+                                           enum vrend_tweak_type t, void *params);
+
+void vrend_set_active_tweaks(struct vrend_context_tweaks *ctx, uint32_t tweak_id, uint32_t tweak_value);
+
+
+void vrend_set_tweak_from_env(struct vrend_context_tweaks *ctx);
+
+#endif // VREND_TWEAKS_H