Vulkan2 Runtime API

Author: ajtulloch

apps/android_rpc/app/src/main/jni/tvm_runtime.h

@@ -62,8 +62,7 @@
 #endif
 
 #ifdef TVM_VULKAN_RUNTIME
-#include "../src/runtime/vulkan/vulkan_device_api.cc"
-#include "../src/runtime/vulkan/vulkan_module.cc"
+#include "../src/runtime/vulkan/vulkan2.cc"
 #endif
 
 #ifdef USE_SORT

cmake/modules/Vulkan.cmake

@@ -29,7 +29,7 @@ if(USE_VULKAN)
     message(FATAL_ERROR "Cannot find Vulkan, USE_VULKAN=" ${USE_VULKAN})
   endif()
   message(STATUS "Build with VULKAN support")
-  file(GLOB RUNTIME_VULKAN_SRCS src/runtime/vulkan/*.cc)
+  file(GLOB RUNTIME_VULKAN_SRCS src/runtime/vulkan/vulkan2.cc)
   file(GLOB COMPILER_VULKAN_SRCS src/codegen/spirv/*.cc)
   list(APPEND RUNTIME_SRCS ${RUNTIME_VULKAN_SRCS})
   list(APPEND COMPILER_SRCS ${COMPILER_VULKAN_SRCS})

src/codegen/spirv/build_vulkan.cc

@@ -29,7 +29,9 @@
 
 #include "codegen_spirv.h"
 #include "../build_common.h"
-#include "../../runtime/vulkan/vulkan_module.h"
+
+#include "../../runtime/vulkan/vulkan2_shader.h"
+#include "../../runtime/vulkan/vulkan2_module.h"
 
 namespace tvm {
 namespace codegen {

src/codegen/spirv/ir_builder.cc

@@ -33,7 +33,10 @@ namespace spirv {
 void IRBuilder::InitHeader() {
   CHECK_EQ(header_.size(), 0U);
   header_.push_back(spv::MagicNumber);
-  header_.push_back(spv::Version);
+  // Use SPIR-V v1.0. This needs to be kept in sync (or at least behind)
+  // `VkApplicationInfo.apiVersion` in `vulkan2.cc` to ensure Vulkan API
+  // validation passes.
+  header_.push_back(0x10000);
   // generator: set to 0, unknown
   header_.push_back(0U);
   // Bound: set during Finalize

src/runtime/vulkan/README.md

@@ -0,0 +1,45 @@
+<!--- Licensed to the Apache Software Foundation (ASF) under one -->
+<!--- or more contributor license agreements.  See the NOTICE file -->
+<!--- distributed with this work for additional information -->
+<!--- regarding copyright ownership.  The ASF licenses this file -->
+<!--- to you under the Apache License, Version 2.0 (the -->
+<!--- "License"); you may not use this file except in compliance -->
+<!--- with the License.  You may obtain a copy of the License at -->
+
+<!---   http://www.apache.org/licenses/LICENSE-2.0 -->
+
+<!--- Unless required by applicable law or agreed to in writing, -->
+<!--- software distributed under the License is distributed on an -->
+<!--- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY -->
+<!--- KIND, either express or implied.  See the License for the -->
+<!--- specific language governing permissions and limitations -->
+<!--- under the License. -->
+
+
+## Components
+
+### Vulkan2DeviceAPI
+
+Implements the TVM DeviceAPI interface. Owns the core Vulkan datastructures. Is responsible for initializing the Vulkan instance and devices, querying for possible extensions.
+
+### Vulkan2ThreadEntry
+
+Thread-local state for the Vulkan runtime. Maintains a staging buffer (for copies), and a Vulkan2Stream per device.
+
+### Vulkan2WrappedFunc
+
+Responsible for launching computation kernels. Responsible for obtaining a
+Vulkan2Pipeline instance (from the Vulkan2ModuleNode), and launches the kernel
+(via immediate or deferred mode) on the active Vulkan2Stream instance.
+
+## Stream execution in the Vulkan programming model.
+
+THe natural model for TVM DeviceAPI implementation and runtime follows the CUDA
+API model. That is, we launch "kernels" onto a (implicit or explicit) "stream"
+(which execute asynchronously with respect to the host, but ordered with respect
+to the stream), and explicitly synchronize the stream with respect to the host.
+We simulate this behaviour in the Vulkan model by maintaining a thread-local
+`vkCommandBuffer` instance, and queueing up (or eagerly executing, depending on
+the availability of the `VK_KHR_push_descriptor` extension). When we synchronize
+the stream, we end the command buffer recording, submit it to the device queue,
+and wait on the corresponding fence.