Integrate audio_streams into crosvm, add stub libcras implementation

The `# ignored by ebuild` tag will remove the path to libcras_stub and
allows crosvm to be built with the actual libcras implementation.

This allows all other platforms to build without depending on
`third_party/adhd/cras/client/libcras`, which is a prerequisite for
externalizing crosvm.

An empty libcras_stub crate is provided to keep cargo happy in external
builds.

To build with cargo against libcras, the setup_cros_cargo.sh script
can be used.

BUG=b:191511078
TEST=Tests in crosvm and cros_sdk both pass:
  $ ./test_all
  $ cros_run_unit_tests --package=crosvm

Cq-Depend: chromium:2993483
Change-Id: I86aad23a86c78e580c1724fb311f870b25d6b09e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2988154
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Dennis Kempin <denniskempin@google.com>
Reviewed-by: Chih-Yang Hsia <paulhsia@chromium.org>

Cargo.lock

@@ -86,6 +86,8 @@ dependencies = [
 name = "audio_streams"
 version = "0.1.0"
 dependencies = [
+ "async-trait",
+ "cros_async",
  "sync",
  "sys_util",
 ]
@@ -166,14 +168,6 @@ dependencies = [
  "bitflags",
 ]
 
-[[package]]
-name = "cras-sys"
-version = "0.1.0"
-dependencies = [
- "audio_streams",
- "data_model",
-]
-
 [[package]]
 name = "crc32fast"
 version = "1.2.1"
@@ -621,13 +615,6 @@ checksum = "18794a8ad5b29321f790b55d93dfba91e125cb1a9edbd4f8e3150acc771c1a5e"
 [[package]]
 name = "libcras"
 version = "0.1.0"
-dependencies = [
- "audio_streams",
- "cras-sys",
- "data_model",
- "libc",
- "sys_util",
-]
 
 [[package]]
 name = "libcrosvm_control"

Cargo.toml

@@ -43,11 +43,13 @@ exclude = [
     "sys_util",
     "tempfile",
     "vm_memory",
+    "audio_streams",
 ]
 
 [features]
 audio = ["devices/audio"]
-chromeos = ["base/chromeos"]
+audio_cras = ["devices/audio_cras"]
+chromeos = ["base/chromeos", "audio_cras"]
 composite-disk = ["protos/composite-disk", "protobuf", "disk/composite-disk"]
 default = ["audio", "gpu", "usb"]
 default-no-sandbox = []
@@ -113,12 +115,11 @@ base = "*"
 
 [patch.crates-io]
 assertions = { path = "assertions" }
-audio_streams = { path = "../../third_party/adhd/audio_streams" } # ignored by ebuild
+audio_streams = { path = "audio_streams" }
 base = { path = "base" }
-cras-sys = { path = "../../third_party/adhd/cras/client/cras-sys" } # ignored by ebuild
 cros_fuzz = { path = "../../platform2/cros-fuzz" } # ignored by ebuild
 data_model = { path = "data_model" }
-libcras = { path = "../../third_party/adhd/cras/client/libcras" } # ignored by ebuild
+libcras = { path = "libcras_stub" } # ignored by ebuild
 minijail = { path = "../../aosp/external/minijail/rust/minijail" } # ignored by ebuild
 p9 = { path = "../../platform2/vm_tools/p9" } # ignored by ebuild
 sync = { path = "sync" }

audio_streams/.gitignore

@@ -1,2 +0,0 @@
-Cargo.lock
-target

audio_streams/Android.bp

@@ -1,7 +0,0 @@
-rust_library_rlib {
-    name: "libaudio_streams",
-    host_supported: true,
-    crate_name: "audio_streams",
-    edition: "2018",
-    srcs: ["src/audio_streams.rs"],
-}

audio_streams/Cargo.toml

@@ -9,6 +9,6 @@ path = "src/audio_streams.rs"
 
 [dependencies]
 async-trait = "0.1.36"
-cros_async = { path = "../../../platform/crosvm/cros_async" } # provided by ebuild
-sync = { path = "../../../platform/crosvm/sync" } # provided by ebuild
-sys_util = { path = "../../../platform/crosvm/sys_util" } # provided by ebuild
+cros_async = { path = "../cros_async" } # provided by ebuild
+sync = { path = "../sync" } # provided by ebuild
+sys_util = { path = "../sys_util" } # provided by ebuild

bin/clippy

@@ -65,6 +65,27 @@ SUPPRESS=(
     new-ret-no-self
 )
 
+FEATURES=(
+    default
+    direct
+    audio
+    gpu
+    plugin
+    power-monitor-powerd
+    tpm
+    usb
+    video-decoder
+    video-encoder
+    wl-dmabuf
+    x
+    virgl_renderer_next
+    composite-disk
+    virgl_renderer
+    gfxstream
+    gdb
+)
+printf -v FEATURES_LIST '%s,' "${FEATURES[@]}"
+
 # Needed or else clippy won't re-run on code that has already compiled.
 if [[ "${USE_CACHE}" == false ]]; then
     cargo clean
@@ -76,5 +97,5 @@ RUST_SYSROOT=$(rustc --print sysroot)
 RUSTFLAGS="${RUSTFLAGS:-}"
 export RUSTFLAGS="$RUSTFLAGS --sysroot=$RUST_SYSROOT"
 
-cargo clippy --all-features --all-targets -- ${SUPPRESS[@]/#/-Aclippy::} \
-    "${CLIPPY_ARGS[@]}" -D warnings
+cargo clippy --features ${FEATURES_LIST} --all-targets -- \
+    ${SUPPRESS[@]/#/-Aclippy::} "${CLIPPY_ARGS[@]}" -D warnings

devices/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2018"
 
 [features]
 audio = []
+audio_cras = ["libcras"]
 direct = []
 gpu = ["gpu_display","rutabaga_gfx"]
 tpm = ["protos/trunks", "tpm2"]
@@ -32,7 +33,7 @@ rutabaga_gfx = { path = "../rutabaga_gfx", optional = true }
 hypervisor = { path = "../hypervisor" }
 kvm_sys = { path = "../kvm_sys" }
 libc = "*"
-libcras = "*"
+libcras = { version = "*", optional = true }
 libvda = { path = "../libvda", optional = true }
 linux_input_sys = { path = "../linux_input_sys" }
 minijail = "*"

devices/src/pci/ac97.rs

@@ -10,6 +10,7 @@ use std::str::FromStr;
 
 use audio_streams::shm_streams::{NullShmStreamSource, ShmStreamSource};
 use base::{error, Event, RawDescriptor};
+#[cfg(feature = "audio_cras")]
 use libcras::{CrasClient, CrasClientType, CrasSocketType, CrasSysError};
 use resources::{Alloc, MmioType, SystemAllocator};
 use vm_memory::GuestMemory;
@@ -39,6 +40,7 @@ const PCI_DEVICE_ID_INTEL_82801AA_5: u16 = 0x2415;
 #[derive(Debug, Clone)]
 pub enum Ac97Backend {
     NULL,
+    #[cfg(feature = "audio_cras")]
     CRAS,
     VIOS,
 }
@@ -71,6 +73,7 @@ impl FromStr for Ac97Backend {
     type Err = Ac97Error;
     fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
         match s {
+            #[cfg(feature = "audio_cras")]
             "cras" => Ok(Ac97Backend::CRAS),
             "vios" => Ok(Ac97Backend::VIOS),
             "null" => Ok(Ac97Backend::NULL),
@@ -85,6 +88,7 @@ pub struct Ac97Parameters {
     pub backend: Ac97Backend,
     pub capture: bool,
     pub vios_server_path: Option<PathBuf>,
+    #[cfg(feature = "audio_cras")]
     client_type: Option<CrasClientType>,
 }
 
@@ -92,6 +96,7 @@ impl Ac97Parameters {
     /// Set CRAS client type by given client type string.
     ///
     /// `client_type` - The client type string.
+    #[cfg(feature = "audio_cras")]
     pub fn set_client_type(&mut self, client_type: &str) -> std::result::Result<(), CrasSysError> {
         self.client_type = Some(client_type.parse()?);
         Ok(())
@@ -145,6 +150,7 @@ impl Ac97Dev {
     /// to create `Ac97Dev` with the given back-end, it'll fallback to the null audio device.
     pub fn try_new(mem: GuestMemory, param: Ac97Parameters) -> Result<Self> {
         match param.backend {
+            #[cfg(feature = "audio_cras")]
             Ac97Backend::CRAS => Self::create_cras_audio_device(param, mem.clone()).or_else(|e| {
                 error!(
                     "Ac97Dev: create_cras_audio_device: {}. Fallback to null audio device",
@@ -160,12 +166,14 @@ impl Ac97Dev {
     /// Return the minijail policy file path for the current Ac97Dev.
     pub fn minijail_policy(&self) -> &'static str {
         match self.backend {
+            #[cfg(feature = "audio_cras")]
             Ac97Backend::CRAS => "cras_audio_device",
             Ac97Backend::VIOS => "vios_audio_device",
             Ac97Backend::NULL => "null_audio_device",
         }
     }
 
+    #[cfg(feature = "audio_cras")]
     fn create_cras_audio_device(params: Ac97Parameters, mem: GuestMemory) -> Result<Self> {
         let mut server = Box::new(
             CrasClient::with_type(CrasSocketType::Unified)

devices/src/pci/pci_device.rs

@@ -27,7 +27,7 @@ pub enum Error {
     /// Registering an IO BAR failed.
     IoRegistrationFailed(u64, pci_configuration::Error),
     /// Create cras client failed.
-    #[cfg(feature = "audio")]
+    #[cfg(all(feature = "audio", feature = "audio_cras"))]
     CreateCrasClientFailed(libcras::Error),
     /// Create VioS client failed.
     #[cfg(feature = "audio")]
@@ -45,7 +45,7 @@ impl Display for Error {
 
         match self {
             CapabilitiesSetup(e) => write!(f, "failed to add capability {}", e),
-            #[cfg(feature = "audio")]
+            #[cfg(all(feature = "audio", feature = "audio_cras"))]
             CreateCrasClientFailed(e) => write!(f, "failed to create CRAS Client: {}", e),
             #[cfg(feature = "audio")]
             CreateViosClientFailed(e) => write!(f, "failed to create VioS Client: {}", e),

libcras_stub/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "libcras"
+version = "0.1.0"
+authors = ["The Chromium OS Authors"]
+edition = "2018"
+
+[lib]
+path = "src/libcras.rs"

libcras_stub/README.md

@@ -0,0 +1,12 @@
+# Stub crate for libcras
+
+libcras is used by ChromeOS to play audio through the cras server.
+
+In ChromeOS builds, the `audio_cras` cargo feature is enabled and this crate is
+replaced with the actual [libcras] implementation.
+
+On other platforms, the feature flag will remain disabled and this crate is used
+to satisfy cargo dependencies on libcras.
+
+[libcras]:
+    https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/third_party/adhd/cras/client/libcras/

libcras_stub/src/libcras.rs

@@ -0,0 +1 @@
+

run_tests

@@ -72,7 +72,7 @@ CRATE_REQUIREMENTS: Dict[str, List[Requirements]] = {
 
 # Just like for crates, lists requirements for each cargo feature flag.
 FEATURE_REQUIREMENTS: Dict[str, List[Requirements]] = {
-    "chromeos": [],
+    "chromeos": [Requirements.DISABLED],
     "audio": [],
     "gpu": [Requirements.CROS_BUILD],
     "plugin": [Requirements.PRIVILEGED, Requirements.X86_64],

setup_cros_cargo.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# Copyright 2021 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file
+#
+# To build crosvm using cargo against libraries and crates provided by ChromeOS
+# use this script to update path references in Cargo.toml.
+#
+# TODO(b/194323235): Add documentation for ChromeOS developer workflows.
+
+sed -i 's|path = "libcras_stub"|path = "../../third_party/adhd/cras/client/libcras"|g' \
+    Cargo.toml
+
+echo "Modified Cargo.toml with new paths. Please do not commit those."

src/main.rs

@@ -533,6 +533,7 @@ fn parse_ac97_options(s: &str) -> argument::Result<Ac97Parameters> {
                     argument::Error::Syntax(format!("invalid capture option: {}", e))
                 })?;
             }
+            #[cfg(feature = "audio_cras")]
             "client_type" => {
                 ac97_params
                     .set_client_type(v)
@@ -2800,7 +2801,7 @@ mod tests {
         );
     }
 
-    #[cfg(feature = "audio")]
+    #[cfg(feature = "audio_cras")]
     #[test]
     fn parse_ac97_vaild() {
         parse_ac97_options("backend=cras").expect("parse should have succeded");
@@ -2812,13 +2813,13 @@ mod tests {
         parse_ac97_options("backend=null").expect("parse should have succeded");
     }
 
-    #[cfg(feature = "audio")]
+    #[cfg(feature = "audio_cras")]
     #[test]
     fn parse_ac97_capture_vaild() {
         parse_ac97_options("backend=cras,capture=true").expect("parse should have succeded");
     }
 
-    #[cfg(feature = "audio")]
+    #[cfg(feature = "audio_cras")]
     #[test]
     fn parse_ac97_client_type() {
         parse_ac97_options("backend=cras,capture=true,client_type=crosvm")