virgl: Add a tweak to set the value for emulated queries of GL_SAMPLES_PASSED

On GLES hosts GL_SAMPLES_PASSED is emulated by GL_ANY_SAMPLES_PASSED which returns a boolen.
With this tweak the value that is returned if any sample passed can be set. This
may be of iterest when an application decides whether some geometry is rendered based
on an amount of visibility and not just a binary desicion. virgelrenderer sets a default
of 1024 on th host.

v2: Remove reference from virgl and correct description (Emil)
v3: Send the tweak binary encoded instead of using strings (Gurchetan)

Signed-off-by: Gert Wollny <[email protected]>
Reviewed-by: Gurchetan Singh <[email protected]>

5 files changed, 12 insertions, 1 deletions

diff --git a/src/gallium/drivers/virgl/virgl_context.c b/src/gallium/drivers/virgl/virgl_context.c
index 5f643788664..987cdc38be2 100644
--- a/src/gallium/drivers/virgl/virgl_context.c
+++ b/src/gallium/drivers/virgl/virgl_context.c
@@ -1409,6 +1409,10 @@ static void virgl_send_tweaks(struct virgl_context *vctx, struct virgl_screen *r
 
    if (rs->tweak_gles_apply_bgra_dest_swizzle)
       virgl_encode_tweak(vctx, virgl_tweak_gles_brga_apply_dest_swizzle, 1);
+
+   if (rs->tweak_gles_tf3_value > 0)
+      virgl_encode_tweak(vctx, virgl_tweak_gles_tf3_samples_passes_multiplier,
+                         rs->tweak_gles_tf3_value);
 }
 
 struct pipe_context *virgl_context_create(struct pipe_screen *pscreen,
diff --git a/src/gallium/drivers/virgl/virgl_driinfo.h.in b/src/gallium/drivers/virgl/virgl_driinfo.h.in
index d6162b3f39a..cbb0bc5a77b 100644
--- a/src/gallium/drivers/virgl/virgl_driinfo.h.in
+++ b/src/gallium/drivers/virgl/virgl_driinfo.h.in
@@ -9,5 +9,5 @@
 DRI_CONF_SECTION_MISCELLANEOUS
     DRI_CONF_GLES_EMULATE_BGRA("false")
     DRI_CONF_GLES_APPLY_BGRA_DEST_SWIZZLE("false")
+    DRI_CONF_GLES_SAMPLES_PASSED_VALUE(int, 1024, "1:400000000")
 DRI_CONF_SECTION_END
-
diff --git a/src/gallium/drivers/virgl/virgl_protocol.h b/src/gallium/drivers/virgl/virgl_protocol.h
index 73795a8a7cd..d14caa292b3 100644
--- a/src/gallium/drivers/virgl/virgl_protocol.h
+++ b/src/gallium/drivers/virgl/virgl_protocol.h
@@ -594,6 +594,7 @@ enum virgl_context_cmd {
 enum vrend_tweak_type {
    virgl_tweak_gles_brga_emulate,
    virgl_tweak_gles_brga_apply_dest_swizzle,
+   virgl_tweak_gles_tf3_samples_passes_multiplier,
    virgl_tweak_undefined
 };
 
diff --git a/src/gallium/drivers/virgl/virgl_screen.c b/src/gallium/drivers/virgl/virgl_screen.c
index e96a10ffbc7..be684dbf3c1 100644
--- a/src/gallium/drivers/virgl/virgl_screen.c
+++ b/src/gallium/drivers/virgl/virgl_screen.c
@@ -856,6 +856,8 @@ virgl_create_screen(struct virgl_winsys *vws, const struct pipe_screen_config *c
 
    const char *VIRGL_GLES_EMULATE_BGRA = "gles_emulate_bgra";
    const char *VIRGL_GLES_APPLY_BGRA_DEST_SWIZZLE = "gles_apply_bgra_dest_swizzle";
+   const char *VIRGL_GLES_SAMPLES_PASSED_VALUE = "gles_samples_passed_value";
+
    if (!screen)
       return NULL;
 
@@ -866,7 +868,10 @@ virgl_create_screen(struct virgl_winsys *vws, const struct pipe_screen_config *c
             driQueryOptionb(config->options, VIRGL_GLES_EMULATE_BGRA);
       screen->tweak_gles_apply_bgra_dest_swizzle =
             driQueryOptionb(config->options, VIRGL_GLES_APPLY_BGRA_DEST_SWIZZLE);
+      screen->tweak_gles_tf3_value =
+            driQueryOptioni(config->options, VIRGL_GLES_SAMPLES_PASSED_VALUE);
    }
+
    screen->vws = vws;
    screen->base.get_name = virgl_get_name;
    screen->base.get_vendor = virgl_get_vendor;
diff --git a/src/gallium/drivers/virgl/virgl_screen.h b/src/gallium/drivers/virgl/virgl_screen.h
index 89b06a25e35..089402d576d 100644
--- a/src/gallium/drivers/virgl/virgl_screen.h
+++ b/src/gallium/drivers/virgl/virgl_screen.h
@@ -48,6 +48,7 @@ struct virgl_screen {
    uint32_t sub_ctx_id;
    bool tweak_gles_emulate_bgra;
    bool tweak_gles_apply_bgra_dest_swizzle;
+   int32_t tweak_gles_tf3_value;
 };