Plumb onTrimMemory app callback to virtualizationservice
Virtualizationservice uses this hint to reclaim guest memory
via the virtio balloon.
Bug: 238931615
Test: atest MicrodroidBenchmarks
Change-Id: Ie4e70160a3305dec68def27667cecd4cd543293f
diff --git a/virtualizationservice/Android.bp b/virtualizationservice/Android.bp
index b767013..da56f76 100644
--- a/virtualizationservice/Android.bp
+++ b/virtualizationservice/Android.bp
@@ -51,6 +51,7 @@
"libshared_child",
"libstatslog_virtualization_rust",
"libtombstoned_client_rust",
+ "libvm_control",
"libvmconfig",
"libzip",
"libvsock",
diff --git a/virtualizationservice/aidl/android/system/virtualizationservice/IVirtualMachine.aidl b/virtualizationservice/aidl/android/system/virtualizationservice/IVirtualMachine.aidl
index d9d9a61..d76b586 100644
--- a/virtualizationservice/aidl/android/system/virtualizationservice/IVirtualMachine.aidl
+++ b/virtualizationservice/aidl/android/system/virtualizationservice/IVirtualMachine.aidl
@@ -16,6 +16,7 @@
package android.system.virtualizationservice;
import android.system.virtualizationservice.IVirtualMachineCallback;
+import android.system.virtualizationservice.MemoryTrimLevel;
import android.system.virtualizationservice.VirtualMachineState;
interface IVirtualMachine {
@@ -41,6 +42,9 @@
*/
void stop();
+ /** Communicate app low-memory notifications to the VM. */
+ void onTrimMemory(MemoryTrimLevel level);
+
/** Open a vsock connection to the CID of the VM on the given port. */
ParcelFileDescriptor connectVsock(int port);
}
diff --git a/virtualizationservice/aidl/android/system/virtualizationservice/MemoryTrimLevel.aidl b/virtualizationservice/aidl/android/system/virtualizationservice/MemoryTrimLevel.aidl
new file mode 100644
index 0000000..9ed9e99
--- /dev/null
+++ b/virtualizationservice/aidl/android/system/virtualizationservice/MemoryTrimLevel.aidl
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed 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.
+ */
+package android.system.virtualizationservice;
+
+/**
+ * Memory trim levels propagated from the app to the VM.
+ */
+@Backing(type="int")
+enum MemoryTrimLevel {
+ /* Same meaning as in ComponentCallbacks2 */
+ TRIM_MEMORY_RUNNING_CRITICAL = 0,
+ TRIM_MEMORY_RUNNING_LOW = 1,
+ TRIM_MEMORY_RUNNING_MODERATE = 2,
+}
diff --git a/virtualizationservice/src/aidl.rs b/virtualizationservice/src/aidl.rs
index 040c0d8..7d24a32 100644
--- a/virtualizationservice/src/aidl.rs
+++ b/virtualizationservice/src/aidl.rs
@@ -27,6 +27,7 @@
IVirtualMachine::{BnVirtualMachine, IVirtualMachine},
IVirtualMachineCallback::IVirtualMachineCallback,
IVirtualizationService::IVirtualizationService,
+ MemoryTrimLevel::MemoryTrimLevel,
Partition::Partition,
PartitionType::PartitionType,
VirtualMachineAppConfig::{Payload::Payload, VirtualMachineAppConfig},
@@ -961,6 +962,13 @@
})
}
+ fn onTrimMemory(&self, level: MemoryTrimLevel) -> binder::Result<()> {
+ self.instance.trim_memory(level).map_err(|e| {
+ error!("Error trimming VM with CID {}: {:?}", self.instance.cid, e);
+ Status::new_service_specific_error_str(-1, Some(e.to_string()))
+ })
+ }
+
fn connectVsock(&self, port: i32) -> binder::Result<ParcelFileDescriptor> {
if !matches!(&*self.instance.vm_state.lock().unwrap(), VmState::Running { .. }) {
return Err(Status::new_service_specific_error_str(-1, Some("VM is not running")));
diff --git a/virtualizationservice/src/crosvm.rs b/virtualizationservice/src/crosvm.rs
index 13e5c70..e535258 100644
--- a/virtualizationservice/src/crosvm.rs
+++ b/virtualizationservice/src/crosvm.rs
@@ -38,7 +38,10 @@
use std::sync::{Arc, Condvar, Mutex};
use std::time::{Duration, SystemTime};
use std::thread;
-use android_system_virtualizationservice::aidl::android::system::virtualizationservice::DeathReason::DeathReason;
+use android_system_virtualizationservice::aidl::android::system::virtualizationservice::{
+ DeathReason::DeathReason,
+ MemoryTrimLevel::MemoryTrimLevel,
+};
use android_system_virtualizationservice_internal::aidl::android::system::virtualizationservice_internal::IGlobalVmContext::IGlobalVmContext;
use binder::Strong;
use android_system_virtualmachineservice::aidl::android::system::virtualmachineservice::IVirtualMachineService::IVirtualMachineService;
@@ -47,6 +50,7 @@
/// external/crosvm
use base::UnixSeqpacketListener;
+use vm_control::{BalloonControlCommand, VmRequest, VmResponse};
const CROSVM_PATH: &str = "/apex/com.android.virt/bin/crosvm";
@@ -171,7 +175,7 @@
// If this fails and returns an error, `self` will be left in the `Failed` state.
let child =
- Arc::new(run_vm(config, &instance.temporary_directory, failure_pipe_write)?);
+ Arc::new(run_vm(config, &instance.crosvm_control_socket_path, failure_pipe_write)?);
let instance_monitor_status = instance.clone();
let child_monitor_status = child.clone();
@@ -228,6 +232,8 @@
vm_context: VmContext,
/// The CID assigned to the VM for vsock communication.
pub cid: Cid,
+ /// Path to crosvm control socket
+ crosvm_control_socket_path: PathBuf,
/// The name of the VM.
pub name: String,
/// Whether the VM is a protected VM.
@@ -268,6 +274,7 @@
vm_state: Mutex::new(VmState::NotStarted { config }),
vm_context,
cid,
+ crosvm_control_socket_path: temporary_directory.join("crosvm.sock"),
name,
protected,
temporary_directory,
@@ -439,6 +446,46 @@
}
}
+ /// Responds to memory-trimming notifications by inflating the virtio
+ /// balloon to reclaim guest memory.
+ pub fn trim_memory(&self, level: MemoryTrimLevel) -> Result<(), Error> {
+ let request = VmRequest::BalloonCommand(BalloonControlCommand::Stats {});
+ match vm_control::client::handle_request(&request, &self.crosvm_control_socket_path) {
+ Ok(VmResponse::BalloonStats { stats, balloon_actual: _ }) => {
+ if let Some(total_memory) = stats.total_memory {
+ // Reclaim up to 50% of total memory assuming worst case
+ // most memory is anonymous and must be swapped to zram
+ // with an approximate 2:1 compression ratio.
+ let pct = match level {
+ MemoryTrimLevel::TRIM_MEMORY_RUNNING_CRITICAL => 50,
+ MemoryTrimLevel::TRIM_MEMORY_RUNNING_LOW => 30,
+ MemoryTrimLevel::TRIM_MEMORY_RUNNING_MODERATE => 10,
+ _ => bail!("Invalid memory trim level {:?}", level),
+ };
+ let command =
+ BalloonControlCommand::Adjust { num_bytes: total_memory * pct / 100 };
+ if let Err(e) = vm_control::client::handle_request(
+ &VmRequest::BalloonCommand(command),
+ &self.crosvm_control_socket_path,
+ ) {
+ bail!("Error sending balloon adjustment: {:?}", e);
+ }
+ }
+ }
+ Ok(VmResponse::Err(e)) => {
+ // ENOTSUP is returned when the balloon protocol is not initialised. This
+ // can occur for numerous reasons: Guest is still booting, guest doesn't
+ // support ballooning, host doesn't support ballooning. We don't log or
+ // raise an error in this case: trim is just a hint and we can ignore it.
+ if e.errno() != libc::ENOTSUP {
+ bail!("Errno return when requesting balloon stats: {}", e.errno())
+ }
+ }
+ e => bail!("Error requesting balloon stats: {:?}", e),
+ }
+ Ok(())
+ }
+
/// Checks if ramdump has been created. If so, send a notification to the user with the handle
/// to read the ramdump.
fn handle_ramdump(&self) -> Result<(), Error> {
@@ -578,7 +625,7 @@
/// Starts an instance of `crosvm` to manage a new VM.
fn run_vm(
config: CrosvmConfig,
- temporary_directory: &Path,
+ crosvm_control_socket_path: &Path,
failure_pipe_write: File,
) -> Result<SharedChild, Error> {
validate_config(&config)?;
@@ -684,9 +731,8 @@
command.arg(add_preserved_fd(&mut preserved_fds, kernel));
}
- let control_server_socket =
- UnixSeqpacketListener::bind(temporary_directory.join("crosvm.sock"))
- .context("failed to create control server")?;
+ let control_server_socket = UnixSeqpacketListener::bind(crosvm_control_socket_path)
+ .context("failed to create control server")?;
command.arg("--socket").arg(add_preserved_fd(&mut preserved_fds, &control_server_socket));
debug!("Preserving FDs {:?}", preserved_fds);