Add an initial wasi-nn implementation for Wasmtime (#2208)

* Add an initial wasi-nn implementation for Wasmtime

This change adds a crate, `wasmtime-wasi-nn`, that uses `wiggle` to expose the current state of the wasi-nn API and `openvino` to implement the exposed functions. It includes an end-to-end test demonstrating how to do classification using wasi-nn:
 - `crates/wasi-nn/tests/classification-example` contains Rust code that is compiled to the `wasm32-wasi` target and run with a Wasmtime embedding that exposes the wasi-nn calls
 - the example uses Rust bindings for wasi-nn contained in `crates/wasi-nn/tests/wasi-nn-rust-bindings`; this crate contains code generated by `witx-bindgen` and eventually should be its own standalone crate

* Test wasi-nn as a CI step

This change adds:
 - a GitHub action for installing OpenVINO
 - a script, `ci/run-wasi-nn-example.sh`, to run the classification example

.github/actions/install-openvino/README.md

@@ -0,0 +1,8 @@
+# install-openvino
+
+A GitHub action to install OpenVINO from a package repository. This is only necessary for `wasi-nn` support but there
+are enough steps here to package the functionality separately and avoid cluttering the CI.
+
+Future improvements:
+ - make this installer work for different OS/distributions (e.g. https://docs.openvinotoolkit.org/latest/openvino_docs_install_guides_installing_openvino_windows.html)
+ - it would be nice to output the install directory (i.e. `/opt/intel/openvino`)

.github/actions/install-openvino/action.yml

@@ -0,0 +1,14 @@
+name: 'Install OpenVINO'
+description: 'Install OpenVINO binaries from a package repository; this is significantly faster than building from source'
+
+inputs:
+  version:
+    description: 'The release version of OpenVINO to install'
+    required: false
+    default: '2020.4.287'
+
+runs:
+  using: composite
+  steps:
+    - run: ${{ github.action_path }}/install.sh ${{ inputs.version }}
+      shell: bash

.github/actions/install-openvino/install.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+set -e
+
+# Retrieve OpenVINO checksum.
+wget https://apt.repos.intel.com/openvino/2020/GPG-PUB-KEY-INTEL-OPENVINO-2020
+echo '5f5cff8a2d26ba7de91942bd0540fa4d  GPG-PUB-KEY-INTEL-OPENVINO-2020' > CHECKSUM
+md5sum --check CHECKSUM
+
+# Add OpenVINO repository (deb).
+sudo apt-key add GPG-PUB-KEY-INTEL-OPENVINO-2020
+echo "deb https://apt.repos.intel.com/openvino/2020 all main" | sudo tee /etc/apt/sources.list.d/intel-openvino-2020.list
+sudo apt update
+
+# Install OpenVINO package.
+sudo apt install -y intel-openvino-runtime-ubuntu18-$1

.github/workflows/main.yml

@@ -51,6 +51,7 @@ jobs:
     runs-on: ubuntu-latest
     env:
       RUSTDOCFLAGS: -Dbroken_intra_doc_links
+      OPENVINO_SKIP_LINKING: 1
     steps:
     - uses: actions/checkout@v2
       with:
@@ -252,6 +253,7 @@ jobs:
             --all \
             --exclude lightbeam \
             --exclude wasmtime-lightbeam \
+            --exclude wasmtime-wasi-nn \
             --exclude peepmatic \
             --exclude peepmatic-automata \
             --exclude peepmatic-fuzzing \
@@ -304,6 +306,23 @@ jobs:
         CARGO_VERSION: "+nightly"
         RUST_BACKTRACE: 1
 
+  # Build and test the wasi-nn module.
+  test_wasi_nn:
+    name: Test wasi-nn module
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: true
+      - uses: ./.github/actions/install-rust
+        with:
+          toolchain: nightly-2020-08-25
+      - run: rustup target add wasm32-wasi
+      - uses: ./.github/actions/install-openvino
+      - run: ./ci/run-wasi-nn-example.sh
+        env:
+          RUST_BACKTRACE: 1
+
   # Verify that cranelift's code generation is deterministic
   meta_determinist_check:
     name: Meta deterministic check
@@ -411,6 +430,7 @@ jobs:
             --all \
             --exclude lightbeam \
             --exclude wasmtime-lightbeam \
+            --exclude wasmtime-wasi-nn \
             --exclude peepmatic \
             --exclude peepmatic-automata \
             --exclude peepmatic-fuzzing \

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "WASI"]
 	path = crates/wasi-common/WASI
 	url = https://github.com/WebAssembly/WASI
+[submodule "crates/wasi-nn/spec"]
+	path = crates/wasi-nn/spec
+	url = https://github.com/WebAssembly/wasi-nn

Cargo.toml

@@ -30,6 +30,7 @@ wasmtime-jit = { path = "crates/jit", version = "0.21.0" }
 wasmtime-obj = { path = "crates/obj", version = "0.21.0" }
 wasmtime-wast = { path = "crates/wast", version = "0.21.0" }
 wasmtime-wasi = { path = "crates/wasi", version = "0.21.0" }
+wasmtime-wasi-nn = { path = "crates/wasi-nn", version = "0.21.0", optional = true }
 wasi-common = { path = "crates/wasi-common", version = "0.21.0" }
 structopt = { version = "0.3.5", features = ["color", "suggestions"] }
 object = { version = "0.22.0", default-features = false, features = ["write"] }
@@ -80,6 +81,7 @@ default = ["jitdump", "wasmtime/wat", "wasmtime/parallel-compilation"]
 lightbeam = ["wasmtime/lightbeam"]
 jitdump = ["wasmtime/jitdump"]
 vtune = ["wasmtime/vtune"]
+wasi-nn = ["wasmtime-wasi-nn"]
 
 # Try the experimental, work-in-progress new x86_64 backend. This is not stable
 # as of June 2020.

ci/run-experimental-x64-ci.sh

@@ -13,6 +13,7 @@ cargo $CARGO_VERSION \
             --features experimental_x64 \
             --all \
             --exclude wasmtime-lightbeam \
+            --exclude wasmtime-wasi-nn \
             --exclude peepmatic \
             --exclude peepmatic-automata \
             --exclude peepmatic-fuzzing \

ci/run-wasi-nn-example.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+
+# The following script demonstrates how to execute a machine learning inference using the wasi-nn module optionally
+# compiled into Wasmtime. Calling it will download the necessary model and tensor files stored separately in $FIXTURE
+# into $TMP_DIR (optionally pass a directory with existing files as the first argument to re-try the script). Then,
+# it will compile the example code in crates/wasi-nn/tests/example into a Wasm file that is subsequently
+# executed with the Wasmtime CLI.
+set -e
+WASMTIME_DIR=$(dirname "$0" | xargs dirname)
+FIXTURE=https://gist.github.com/abrown/c7847bf3701f9efbb2070da1878542c1/raw/07a9f163994b0ff8f0d7c5a5c9645ec3d8b24024
+
+# Inform the environment of OpenVINO library locations. Then we use OPENVINO_INSTALL_DIR below to avoid building all of
+# OpenVINO from source (quite slow).
+source /opt/intel/openvino/bin/setupvars.sh
+
+# Build Wasmtime with wasi-nn enabled; we attempt this first to avoid extra work if the build fails.
+OPENVINO_INSTALL_DIR=/opt/intel/openvino cargo build -p wasmtime-cli --features wasi-nn
+
+# Download all necessary test fixtures to the temporary directory.
+TMP_DIR=${1:-$(mktemp -d -t ci-XXXXXXXXXX)}
+wget --no-clobber --directory-prefix=$TMP_DIR $FIXTURE/frozen_inference_graph.bin
+wget --no-clobber --directory-prefix=$TMP_DIR $FIXTURE/frozen_inference_graph.xml
+wget --no-clobber --directory-prefix=$TMP_DIR $FIXTURE/tensor-1x3x300x300-f32.bgr
+
+# Now build an example that uses the wasi-nn API.
+pushd $WASMTIME_DIR/crates/wasi-nn/examples/classification-example
+cargo build --release --target=wasm32-wasi
+cp target/wasm32-wasi/release/wasi-nn-example.wasm $TMP_DIR
+popd
+
+# Run the example in Wasmtime (note that the example uses `fixture` as the expected location of the model/tensor files).
+OPENVINO_INSTALL_DIR=/opt/intel/openvino cargo run --features wasi-nn -- run --mapdir fixture::$TMP_DIR $TMP_DIR/wasi-nn-example.wasm
+
+# Clean up.
+rm -rf $TMP_DIR

crates/wasi-nn/Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name = "wasmtime-wasi-nn"
+version = "0.21.0"
+authors = ["The Wasmtime Project Developers"]
+description = "Wasmtime implementation of the wasi-nn API"
+documentation = "https://docs.rs/wasmtime-wasi-nn"
+license = "Apache-2.0 WITH LLVM-exception"
+categories = ["wasm", "computer-vision"]
+keywords = ["webassembly", "wasm", "neural network"]
+repository = "https://github.com/bytecodealliance/wasmtime"
+readme = "README.md"
+edition = "2018"
+
+[dependencies]
+# These dependencies are necessary for the witx-generation macros to work:
+anyhow = "1.0"
+log = { version = "0.4", default-features = false }
+wasmtime = { path = "../wasmtime", version = "0.21.0", default-features = false }
+wasmtime-runtime = { path = "../runtime", version = "0.21.0" }
+wasmtime-wiggle = { path = "../wiggle/wasmtime", version = "0.21.0" }
+wasmtime-wasi = { path = "../wasi", version = "0.21.0" }
+wiggle = { path = "../wiggle", version = "0.21.0" }
+
+# These dependencies are necessary for the wasi-nn implementation:
+openvino = "0.1.5"
+thiserror = "1.0"
+
+[badges]
+maintenance = { status = "experimental" }