1 /*
2 * Copyright 2022 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 //! Detection for nested virtualization.
18
19 use anyhow::Result;
20 use rustutils::system_properties;
21
22 /// Return whether we will be running our VM in a VM, which causes the nested VM to run very slowly.
is_nested_virtualization() -> Result<bool>23 pub fn is_nested_virtualization() -> Result<bool> {
24 // Nested virtualization occurs when we run KVM inside the cuttlefish VM or when
25 // we run trusty within qemu.
26 let checks = [
27 ("ro.product.vendor.device", "vsoc_"), // vsoc_x86, vsoc_x86_64, vsoc_x86_64_only, ...
28 ("ro.hardware", "qemu_"), // qemu_trusty, ...
29 ];
30
31 for (property, prefix) in checks {
32 if let Some(value) = system_properties::read(property)? {
33 if value.starts_with(prefix) {
34 return Ok(true);
35 }
36 }
37 }
38
39 // No match -> not nested
40 Ok(false)
41 }
42