add option for custom vCPU count
Only supported by VirtualMachineRawConfig.
It has been observed that >1 vCPU hurts performance in some cases when
not also setting the CPU affinities and performing other tweaks, as done
by MATCH_HOST, so we avoided adding this before. However, there are
probably use cases where it is the best option and we've been explicitly
asked by partners to add it.
Bug: 381281047
Test: m
Change-Id: Ic22c747d064e70505398eb438a210ef42b5d75e1
diff --git a/android/virtmgr/src/aidl.rs b/android/virtmgr/src/aidl.rs
index 79c7d81..15a80a6 100644
--- a/android/virtmgr/src/aidl.rs
+++ b/android/virtmgr/src/aidl.rs
@@ -653,6 +653,14 @@
let (cpus, host_cpu_topology) = match config.cpuTopology {
CpuTopology::MATCH_HOST => (None, true),
CpuTopology::ONE_CPU => (NonZeroU32::new(1), false),
+ CpuTopology::CUSTOM => (
+ NonZeroU32::new(
+ u32::try_from(config.customVcpuCount)
+ .context("bad customVcpuCount")
+ .or_binder_exception(ExceptionCode::ILLEGAL_ARGUMENT)?,
+ ),
+ false,
+ ),
val => {
return Err(anyhow!("Failed to parse CPU topology value {:?}", val))
.with_log()
@@ -1228,6 +1236,9 @@
vm_config.name.clone_from(&config.name);
vm_config.protectedVm = config.protectedVm;
vm_config.cpuTopology = config.cpuTopology;
+ if config.cpuTopology == CpuTopology::CUSTOM {
+ bail!("AppConfig doesn't support CpuTopology::CUSTOM");
+ }
vm_config.hugePages = config.hugePages || vm_payload_config.hugepages;
vm_config.boostUclamp = config.boostUclamp;
diff --git a/android/virtmgr/src/atom.rs b/android/virtmgr/src/atom.rs
index 45b020e..e0fed85 100644
--- a/android/virtmgr/src/atom.rs
+++ b/android/virtmgr/src/atom.rs
@@ -92,6 +92,26 @@
}
}
+fn get_num_vcpus(cpu_topology: CpuTopology, custom_vcpu_count: Option<i32>) -> i32 {
+ match cpu_topology {
+ CpuTopology::ONE_CPU => 1,
+ CpuTopology::MATCH_HOST => {
+ get_num_cpus().and_then(|v| v.try_into().ok()).unwrap_or_else(|| {
+ warn!("Failed to determine the number of CPUs in the host");
+ INVALID_NUM_CPUS
+ })
+ }
+ CpuTopology::CUSTOM => custom_vcpu_count.unwrap_or_else(|| {
+ warn!("AppConfig doesn't support CpuTopology::CUSTOM");
+ INVALID_NUM_CPUS
+ }),
+ _ => {
+ warn!("invalid CpuTopology: {cpu_topology:?}");
+ INVALID_NUM_CPUS
+ }
+ }
+}
+
/// Write the stats of VMCreation to statsd
/// The function creates a separate thread which waits for statsd to start to push atom
pub fn write_vm_creation_stats(
@@ -115,33 +135,24 @@
binder_exception_code = e.exception_code() as i32;
}
}
- let (vm_identifier, config_type, cpu_topology, memory_mib, apexes) = match config {
+
+ let (vm_identifier, config_type, num_cpus, memory_mib, apexes) = match config {
VirtualMachineConfig::AppConfig(config) => (
config.name.clone(),
vm_creation_requested::ConfigType::VirtualMachineAppConfig,
- config.cpuTopology,
+ get_num_vcpus(config.cpuTopology, None),
config.memoryMib,
get_apex_list(config),
),
VirtualMachineConfig::RawConfig(config) => (
config.name.clone(),
vm_creation_requested::ConfigType::VirtualMachineRawConfig,
- config.cpuTopology,
+ get_num_vcpus(config.cpuTopology, Some(config.customVcpuCount)),
config.memoryMib,
String::new(),
),
};
- let num_cpus: i32 = match cpu_topology {
- CpuTopology::MATCH_HOST => {
- get_num_cpus().and_then(|v| v.try_into().ok()).unwrap_or_else(|| {
- warn!("Failed to determine the number of CPUs in the host");
- INVALID_NUM_CPUS
- })
- }
- _ => 1,
- };
-
let atom = AtomVmCreationRequested {
uid: get_calling_uid() as i32,
vmIdentifier: vm_identifier,
diff --git a/android/virtualizationservice/aidl/android/system/virtualizationservice/CpuTopology.aidl b/android/virtualizationservice/aidl/android/system/virtualizationservice/CpuTopology.aidl
index 8a8e3d0..31a33f4 100644
--- a/android/virtualizationservice/aidl/android/system/virtualizationservice/CpuTopology.aidl
+++ b/android/virtualizationservice/aidl/android/system/virtualizationservice/CpuTopology.aidl
@@ -22,4 +22,6 @@
ONE_CPU = 0,
/** Match physical CPU topology of the host. */
MATCH_HOST = 1,
+ /** Number of vCPUs specified in the config. */
+ CUSTOM = 2,
}
diff --git a/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineRawConfig.aidl b/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineRawConfig.aidl
index 3393546..d98fdcc 100644
--- a/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineRawConfig.aidl
+++ b/android/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachineRawConfig.aidl
@@ -65,6 +65,9 @@
/** The vCPU topology that will be generated for the VM. Default to 1 vCPU. */
CpuTopology cpuTopology = CpuTopology.ONE_CPU;
+ /** The number of vCPUs. Ignored unless `cpuTopology == CUSTOM`. */
+ int customVcpuCount;
+
/**
* A version or range of versions of the virtual platform that this config is compatible with.
* The format follows SemVer.