gpuav: Validate BLAS ref alignment in TLAS build

Author: arno-lunarg

layers/gpuav/shaders/gpuav_error_codes.h

@@ -165,10 +165,11 @@ const int kErrorSubCodePreCopyMemoryToImageIndirectSrcAddressInvalid = 9;
 
 // Pre Build Acceleration Structures
 //
-const int kErrorSubCode_PreBuildAccelerationStructures_InvalidAS = 1;
-const int kErrorSubCode_PreBuildAccelerationStructures_DestroyedASBuffer = 2;
-const int kErrorSubCode_PreBuildAccelerationStructures_InvalidASType = 3;
-const int kErrorSubCode_PreBuildAccelerationStructures_BlasMemoryOverlap = 4;
+const int kErrorSubCode_PreBuildAccelerationStructures_BlasAddrAlignment = 1;
+const int kErrorSubCode_PreBuildAccelerationStructures_InvalidAS = 2;
+const int kErrorSubCode_PreBuildAccelerationStructures_DestroyedASBuffer = 3;
+const int kErrorSubCode_PreBuildAccelerationStructures_InvalidASType = 4;
+const int kErrorSubCode_PreBuildAccelerationStructures_BlasMemoryOverlap = 5;
 
 #ifdef __cplusplus
 }  // namespace glsl

layers/gpuav/shaders/validation_cmd/build_acceleration_structures.comp

@@ -56,7 +56,9 @@ void main() {
 
     uint error_subcode = 0;
 
-    if (pc.validation_mode == kBuildASValidationMode_invalid_AS) {
+    if ((blas_addr % 16u ) != 0) {
+        error_subcode = kErrorSubCode_PreBuildAccelerationStructures_BlasAddrAlignment;
+    } else if (pc.validation_mode == kBuildASValidationMode_invalid_AS) {
         error_subcode = kErrorSubCode_PreBuildAccelerationStructures_InvalidAS;
         const uint as_count = pc.ptr_to_ptr_to_accel_structs_arrays.as_arrays_ptrs.addresses_ptr.count;
         for (uint as_i = 0; as_i < as_count; ++as_i) {

layers/gpuav/validation_cmd/gpuav_ray_tracing.cpp

@@ -625,6 +625,11 @@ void BuildAccelerationStructures(Validator& gpuav, const Location& loc, CommandB
         // ---
         const uint32_t error_sub_code = GetSubError(error_record);
         switch (error_sub_code) {
+            case kErrorSubCode_PreBuildAccelerationStructures_BlasAddrAlignment: {
+                skip |= gpuav.LogError("VUID-vkCmdBuildAccelerationStructuresKHR-pInfos-03717", objlist, loc_with_debug_region,
+                                       "%s is not aligned to 16 bytes.", invalid_blas_loc_str.c_str());
+                break;
+            }
             case kErrorSubCode_PreBuildAccelerationStructures_InvalidAS: {
                 skip |= gpuav.LogError("VUID-vkCmdBuildAccelerationStructuresKHR-pInfos-12281", objlist, loc_with_debug_region,
                                        "%s is an invalid acceleration structure reference.", invalid_blas_loc_str.c_str());