radv/rt: Add workaround to make leaves always active

DOOM Eternal builds acceleration structures with inactive primitives and
tries to make them active in later AS updates. This is disallowed by the
spec and triggers a GPU hang. Fix the hang by working around the bug.

Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27034>
(cherry picked from commit a9831caa14)

.pick_status.json

@@ -124,7 +124,7 @@
         "description": "radv/rt: Add workaround to make leaves always active",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null,
         "notes": null

src/amd/vulkan/bvh/build_helpers.h

@@ -156,6 +156,7 @@
 
 #define VK_GEOMETRY_TYPE_TRIANGLES_KHR 0
 #define VK_GEOMETRY_TYPE_AABBS_KHR     1
+#define VK_GEOMETRY_TYPE_INSTANCES_KHR 2
 
 #define VK_GEOMETRY_INSTANCE_TRIANGLE_FACING_CULL_DISABLE_BIT_KHR 1
 #define VK_GEOMETRY_INSTANCE_TRIANGLE_FLIP_FACING_BIT_KHR         2

src/amd/vulkan/bvh/leaf.comp

@@ -333,6 +333,14 @@ main(void)
       is_active = build_instance(bounds, src_ptr, dst_ptr, global_id);
    }
 
+#if ALWAYS_ACTIVE
+   if (!is_active && args.geometry_type != VK_GEOMETRY_TYPE_INSTANCES_KHR) {
+      bounds.min = vec3(0.0);
+      bounds.max = vec3(0.0);
+      is_active = true;
+   }
+#endif
+
    DEREF(id_ptr).id = is_active ? pack_ir_node_id(dst_offset, node_type) : RADV_BVH_INVALID_NODE;
 
    uvec4 ballot = subgroupBallot(is_active);

src/amd/vulkan/bvh/meson.build

@@ -53,7 +53,12 @@ bvh_shaders = [
   [
     'leaf.comp',
     'leaf',
-    [],
+    ['ALWAYS_ACTIVE=0'],
+  ],
+  [
+    'leaf.comp',
+    'leaf_always_active',
+    ['ALWAYS_ACTIVE=1'],
   ],
   [
     'morton.comp',

src/amd/vulkan/radv_acceleration_structure.c

@@ -41,6 +41,10 @@ static const uint32_t leaf_spv[] = {
 #include "bvh/leaf.spv.h"
 };
 
+static const uint32_t leaf_always_active_spv[] = {
+#include "bvh/leaf_always_active.spv.h"
+};
+
 static const uint32_t morton_spv[] = {
 #include "bvh/morton.spv.h"
 };
@@ -513,9 +517,14 @@ radv_device_init_accel_struct_build_state(struct radv_device *device)
    if (device->meta_state.accel_struct_build.radix_sort)
       goto exit;
 
-   result = create_build_pipeline_spv(device, leaf_spv, sizeof(leaf_spv), sizeof(struct leaf_args),
-                                      &device->meta_state.accel_struct_build.leaf_pipeline,
-                                      &device->meta_state.accel_struct_build.leaf_p_layout);
+   if (device->instance->force_active_accel_struct_leaves)
+      result = create_build_pipeline_spv(device, leaf_always_active_spv, sizeof(leaf_always_active_spv),
+                                         sizeof(struct leaf_args), &device->meta_state.accel_struct_build.leaf_pipeline,
+                                         &device->meta_state.accel_struct_build.leaf_p_layout);
+   else
+      result = create_build_pipeline_spv(device, leaf_spv, sizeof(leaf_spv), sizeof(struct leaf_args),
+                                         &device->meta_state.accel_struct_build.leaf_pipeline,
+                                         &device->meta_state.accel_struct_build.leaf_p_layout);
    if (result != VK_SUCCESS)
       goto exit;
 

src/amd/vulkan/radv_instance.c

@@ -154,6 +154,7 @@ static const driOptionDescription radv_dri_options[] = {
       DRI_CONF_RADV_RT_WAVE64(false)
       DRI_CONF_DUAL_COLOR_BLEND_BY_LOCATION(false)
       DRI_CONF_RADV_SSBO_NON_UNIFORM(false)
+      DRI_CONF_RADV_FORCE_ACTIVE_ACCEL_STRUCT_LEAVES(false)
       DRI_CONF_RADV_APP_LAYER()
    DRI_CONF_SECTION_END
 };
@@ -214,6 +215,9 @@ radv_init_dri_options(struct radv_instance *instance)
    instance->force_rt_wave64 = driQueryOptionb(&instance->dri_options, "radv_rt_wave64");
 
    instance->dual_color_blend_by_location = driQueryOptionb(&instance->dri_options, "dual_color_blend_by_location");
+
+   instance->force_active_accel_struct_leaves =
+      driQueryOptionb(&instance->dri_options, "radv_force_active_accel_struct_leaves");
 }
 
 static const struct vk_instance_extension_table radv_instance_extensions_supported = {

src/amd/vulkan/radv_private.h

@@ -420,6 +420,7 @@ struct radv_instance {
    bool flush_before_timestamp_write;
    bool force_rt_wave64;
    bool dual_color_blend_by_location;
+   bool force_active_accel_struct_leaves;
    char *app_layer;
 };
 

src/util/00-radv-defaults.conf

@@ -104,6 +104,7 @@ Application bugs worked around in this file:
 
         <application name="DOOM Eternal" application_name_match="DOOMEternal">
             <option name="radv_zero_vram" value="true" />
+            <option name="radv_force_active_accel_struct_leaves" value="true" />
         </application>
 
         <application name="No Man's Sky" application_name_match="No Man's Sky">

src/util/driconf.h

@@ -688,6 +688,10 @@
 
 #define DRI_CONF_RADV_APP_LAYER() DRI_CONF_OPT_S_NODEF(radv_app_layer, "Select an application layer.")
 
+#define DRI_CONF_RADV_FORCE_ACTIVE_ACCEL_STRUCT_LEAVES(def) \
+   DRI_CONF_OPT_B(radv_force_active_accel_struct_leaves, def, \
+                  "Force leaf nodes of acceleration structures to be marked active.")
+
 /**
  * \brief ANV specific configuration options
  */