Revert^2 "Add microfuchsia apex that runs in AVF on bootup"
4ae215a64209cfbb0ae4fb2d484a0fb4fa4afc53
The old change is PS1.
The fix involves using libc::c_char and casting to a u8 on x86
architectures.
Test: m com.android.microfuchsia for arm and x86
Change-Id: Ideccd80b4f6a812c1638b31a7b4ad666a5a411b7
diff --git a/microfuchsia/microfuchsiad/src/instance_starter.rs b/microfuchsia/microfuchsiad/src/instance_starter.rs
new file mode 100644
index 0000000..15fcc06
--- /dev/null
+++ b/microfuchsia/microfuchsiad/src/instance_starter.rs
@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) 2024 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.
+ */
+
+//! Responsible for starting an instance of the Microfuchsia VM.
+
+use android_system_virtualizationservice::aidl::android::system::virtualizationservice::{
+ CpuTopology::CpuTopology, IVirtualizationService::IVirtualizationService,
+ VirtualMachineConfig::VirtualMachineConfig, VirtualMachineRawConfig::VirtualMachineRawConfig,
+};
+use anyhow::{ensure, Context, Result};
+use binder::{LazyServiceGuard, ParcelFileDescriptor};
+use log::info;
+use std::ffi::CStr;
+use std::fs::File;
+use std::os::fd::FromRawFd;
+use vmclient::VmInstance;
+
+pub struct MicrofuchsiaInstance {
+ _vm_instance: VmInstance,
+ _lazy_service_guard: LazyServiceGuard,
+ _pty: Pty,
+}
+
+pub struct InstanceStarter {
+ instance_name: String,
+ instance_id: u8,
+}
+
+impl InstanceStarter {
+ pub fn new(instance_name: &str, instance_id: u8) -> Self {
+ Self { instance_name: instance_name.to_owned(), instance_id }
+ }
+
+ pub fn start_new_instance(
+ &self,
+ virtualization_service: &dyn IVirtualizationService,
+ ) -> Result<MicrofuchsiaInstance> {
+ info!("Creating {} instance", self.instance_name);
+
+ // Always use instance id 0, because we will only ever have one instance.
+ let mut instance_id = [0u8; 64];
+ instance_id[0] = self.instance_id;
+
+ // Open the kernel and initrd files from the microfuchsia.images apex.
+ let kernel_fd =
+ File::open("/apex/com.android.microfuchsia.images/etc/linux-arm64-boot-shim.bin")
+ .context("Failed to open the boot-shim")?;
+ let initrd_fd = File::open("/apex/com.android.microfuchsia.images/etc/fuchsia.zbi")
+ .context("Failed to open the fuchsia ZBI")?;
+ let kernel = Some(ParcelFileDescriptor::new(kernel_fd));
+ let initrd = Some(ParcelFileDescriptor::new(initrd_fd));
+
+ // Prepare a pty for console input/output.
+ let pty = openpty()?;
+ let console_in = Some(pty.leader.try_clone().context("cloning pty")?);
+ let console_out = Some(pty.leader.try_clone().context("cloning pty")?);
+
+ let config = VirtualMachineConfig::RawConfig(VirtualMachineRawConfig {
+ name: "Microfuchsia".into(),
+ instanceId: instance_id,
+ kernel,
+ initrd,
+ params: None,
+ bootloader: None,
+ disks: vec![],
+ protectedVm: false,
+ memoryMib: 256,
+ cpuTopology: CpuTopology::ONE_CPU,
+ platformVersion: "1.0.0".into(),
+ // Fuchsia uses serial for console by default.
+ consoleInputDevice: Some("ttyS0".into()),
+ ..Default::default()
+ });
+ let vm_instance = VmInstance::create(
+ virtualization_service,
+ &config,
+ console_out,
+ console_in,
+ /* log= */ None,
+ None,
+ )
+ .context("Failed to create VM")?;
+ vm_instance
+ .vm
+ .setHostConsoleName(&pty.follower_name)
+ .context("Setting host console name")?;
+ vm_instance.start().context("Starting VM")?;
+
+ Ok(MicrofuchsiaInstance {
+ _vm_instance: vm_instance,
+ _lazy_service_guard: Default::default(),
+ _pty: pty,
+ })
+ }
+}
+
+struct Pty {
+ leader: File,
+ follower_name: String,
+}
+
+/// Opens a pseudoterminal (pty), configures it to be a raw terminal, and returns the file pair.
+fn openpty() -> Result<Pty> {
+ // Create a pty pair.
+ let mut leader: libc::c_int = -1;
+ let mut _follower: libc::c_int = -1;
+ let mut follower_name: Vec<libc::c_char> = vec![0; 32];
+
+ // SAFETY: calling openpty with valid+initialized variables is safe.
+ // The two null pointers are valid inputs for openpty.
+ unsafe {
+ ensure!(
+ libc::openpty(
+ &mut leader,
+ &mut _follower,
+ follower_name.as_mut_ptr(),
+ std::ptr::null_mut(),
+ std::ptr::null_mut(),
+ ) == 0,
+ "failed to openpty"
+ );
+ }
+
+ // SAFETY: calling these libc functions with valid+initialized variables is safe.
+ unsafe {
+ // Fetch the termios attributes.
+ let mut attr = libc::termios {
+ c_iflag: 0,
+ c_oflag: 0,
+ c_cflag: 0,
+ c_lflag: 0,
+ c_line: 0,
+ c_cc: [0u8; 19],
+ };
+ ensure!(libc::tcgetattr(leader, &mut attr) == 0, "failed to get termios attributes");
+
+ // Force it to be a raw pty and re-set it.
+ libc::cfmakeraw(&mut attr);
+ ensure!(
+ libc::tcsetattr(leader, libc::TCSANOW, &attr) == 0,
+ "failed to set termios attributes"
+ );
+ }
+
+ // Construct the return value.
+ // SAFETY: The file descriptors are valid because openpty returned without error (above).
+ let leader = unsafe { File::from_raw_fd(leader) };
+ let follower_name: Vec<u8> = follower_name.iter_mut().map(|x| *x as _).collect();
+ let follower_name = CStr::from_bytes_until_nul(&follower_name)
+ .context("pty filename missing NUL")?
+ .to_str()
+ .context("pty filename invalid utf8")?
+ .to_string();
+ Ok(Pty { leader, follower_name })
+}