| // Copyright 2017 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. |
| |
| use std; |
| use std::cmp::min; |
| use std::ffi::CStr; |
| use std::fmt; |
| use std::error; |
| use std::fs::{File, OpenOptions}; |
| use std::io::{self, Read, stdin}; |
| use std::mem; |
| use std::os::unix::io::{FromRawFd, RawFd}; |
| use std::os::unix::net::UnixDatagram; |
| use std::path::{Path, PathBuf}; |
| use std::str; |
| use std::sync::atomic::{AtomicBool, Ordering}; |
| use std::sync::{Arc, Barrier}; |
| use std::thread; |
| use std::time::Duration; |
| use std::thread::JoinHandle; |
| |
| use libc::{self, c_int}; |
| use rand::thread_rng; |
| use rand::distributions::{IndependentSample, Range}; |
| |
| use byteorder::{ByteOrder, LittleEndian}; |
| use devices; |
| use io_jail::{self, Minijail}; |
| use kvm::*; |
| use net_util::Tap; |
| use qcow::{self, QcowFile}; |
| use sys_util::*; |
| use sys_util; |
| use vhost; |
| use vm_control::VmRequest; |
| |
| use Config; |
| use DiskType; |
| use VirtIoDeviceInfo; |
| |
| use arch::{self, LinuxArch, RunnableLinuxVm, VirtioDeviceStub, VmComponents}; |
| |
| #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] |
| use x86_64::X8664arch as Arch; |
| #[cfg(any(target_arch = "arm", target_arch = "aarch64"))] |
| use aarch64::AArch64 as Arch; |
| |
| #[derive(Debug)] |
| pub enum Error { |
| BalloonDeviceNew(devices::virtio::BalloonError), |
| BlockDeviceNew(sys_util::Error), |
| BlockSignal(sys_util::signal::Error), |
| BuildingVm(Box<error::Error>), |
| CloneEventFd(sys_util::Error), |
| CreateEventFd(sys_util::Error), |
| CreatePollContext(sys_util::Error), |
| CreateSignalFd(sys_util::SignalFdError), |
| CreateSocket(io::Error), |
| CreateTimerFd(sys_util::Error), |
| DeviceJail(io_jail::Error), |
| DevicePivotRoot(io_jail::Error), |
| Disk(io::Error), |
| DiskImageLock(sys_util::Error), |
| FailedCLOEXECCheck, |
| FailedToDupFd, |
| InvalidFdPath, |
| NetDeviceNew(devices::virtio::NetError), |
| NoVarEmpty, |
| OpenKernel(PathBuf, io::Error), |
| P9DeviceNew(devices::virtio::P9Error), |
| PollContextAdd(sys_util::Error), |
| PollContextDelete(sys_util::Error), |
| QcowDeviceCreate(qcow::Error), |
| ReadLowmemAvailable(io::Error), |
| ReadLowmemMargin(io::Error), |
| RegisterBalloon(arch::MmioRegisterError), |
| RegisterBlock(arch::MmioRegisterError), |
| RegisterGpu(arch::MmioRegisterError), |
| RegisterNet(arch::MmioRegisterError), |
| RegisterP9(arch::MmioRegisterError), |
| RegisterRng(arch::MmioRegisterError), |
| RegisterSignalHandler(sys_util::Error), |
| RegisterWayland(arch::MmioRegisterError), |
| ResetTimerFd(sys_util::Error), |
| RngDeviceNew(devices::virtio::RngError), |
| SettingGidMap(io_jail::Error), |
| SettingUidMap(io_jail::Error), |
| SignalFd(sys_util::SignalFdError), |
| SpawnVcpu(io::Error), |
| TimerFd(sys_util::Error), |
| VhostNetDeviceNew(devices::virtio::vhost::Error), |
| VhostVsockDeviceNew(devices::virtio::vhost::Error), |
| WaylandDeviceNew(sys_util::Error), |
| LoadKernel(Box<error::Error>), |
| } |
| |
| impl fmt::Display for Error { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| match self { |
| &Error::BalloonDeviceNew(ref e) => write!(f, "failed to create balloon: {:?}", e), |
| &Error::BlockDeviceNew(ref e) => write!(f, "failed to create block device: {:?}", e), |
| &Error::BlockSignal(ref e) => write!(f, "failed to block signal: {:?}", e), |
| &Error::BuildingVm(ref e) => { |
| write!(f, "The architecture failed to build the vm: {:?}", e) |
| } |
| &Error::CloneEventFd(ref e) => write!(f, "failed to clone eventfd: {:?}", e), |
| &Error::CreateEventFd(ref e) => write!(f, "failed to create eventfd: {:?}", e), |
| &Error::CreatePollContext(ref e) => write!(f, "failed to create poll context: {:?}", e), |
| &Error::CreateSignalFd(ref e) => write!(f, "failed to create signalfd: {:?}", e), |
| &Error::CreateSocket(ref e) => write!(f, "failed to create socket: {}", e), |
| &Error::CreateTimerFd(ref e) => write!(f, "failed to create timerfd: {}", e), |
| &Error::DeviceJail(ref e) => write!(f, "failed to jail device: {}", e), |
| &Error::DevicePivotRoot(ref e) => write!(f, "failed to pivot root device: {}", e), |
| &Error::Disk(ref e) => write!(f, "failed to load disk image: {}", e), |
| &Error::DiskImageLock(ref e) => write!(f, "failed to lock disk image: {:?}", e), |
| &Error::FailedCLOEXECCheck => { |
| write!(f, "/proc/self/fd argument failed check for CLOEXEC") |
| } |
| &Error::FailedToDupFd => write!(f, "failed to dup fd from /proc/self/fd"), |
| &Error::InvalidFdPath => write!(f, "failed parsing a /proc/self/fd/*"), |
| &Error::NetDeviceNew(ref e) => write!(f, "failed to set up virtio networking: {:?}", e), |
| &Error::NoVarEmpty => write!(f, "/var/empty doesn't exist, can't jail devices."), |
| &Error::OpenKernel(ref p, ref e) => { |
| write!(f, "failed to open kernel image {:?}: {}", p, e) |
| } |
| &Error::P9DeviceNew(ref e) => write!(f, "failed to create 9p device: {}", e), |
| &Error::PollContextAdd(ref e) => write!(f, "failed to add fd to poll context: {:?}", e), |
| &Error::PollContextDelete(ref e) => { |
| write!(f, "failed to remove fd from poll context: {:?}", e) |
| } |
| &Error::QcowDeviceCreate(ref e) => { |
| write!(f, "failed to read qcow formatted file {:?}", e) |
| } |
| &Error::ReadLowmemAvailable(ref e) => { |
| write!(f, "failed to read /sys/kernel/mm/chromeos-low_mem/available: {}", e) |
| } |
| &Error::ReadLowmemMargin(ref e) => { |
| write!(f, "failed to read /sys/kernel/mm/chromeos-low_mem/margin: {}", e) |
| } |
| &Error::RegisterBalloon(ref e) => { |
| write!(f, "error registering balloon device: {:?}", e) |
| }, |
| &Error::RegisterBlock(ref e) => write!(f, "error registering block device: {:?}", e), |
| &Error::RegisterGpu(ref e) => write!(f, "error registering gpu device: {:?}", e), |
| &Error::RegisterNet(ref e) => write!(f, "error registering net device: {:?}", e), |
| &Error::RegisterP9(ref e) => write!(f, "error registering 9p device: {:?}", e), |
| &Error::RegisterRng(ref e) => write!(f, "error registering rng device: {:?}", e), |
| &Error::RegisterSignalHandler(ref e) => { |
| write!(f, "error registering signal handler: {:?}", e) |
| } |
| &Error::RegisterWayland(ref e) => write!(f, "error registering wayland device: {}", e), |
| &Error::ResetTimerFd(ref e) => write!(f, "failed to reset timerfd: {}", e), |
| &Error::RngDeviceNew(ref e) => write!(f, "failed to set up rng: {:?}", e), |
| &Error::SettingGidMap(ref e) => write!(f, "error setting GID map: {}", e), |
| &Error::SettingUidMap(ref e) => write!(f, "error setting UID map: {}", e), |
| &Error::SignalFd(ref e) => write!(f, "failed to read signal fd: {:?}", e), |
| &Error::SpawnVcpu(ref e) => write!(f, "failed to spawn VCPU thread: {:?}", e), |
| &Error::TimerFd(ref e) => write!(f, "failed to read timer fd: {:?}", e), |
| &Error::VhostNetDeviceNew(ref e) => { |
| write!(f, "failed to set up vhost networking: {:?}", e) |
| } |
| &Error::VhostVsockDeviceNew(ref e) => { |
| write!(f, "failed to set up virtual socket device: {:?}", e) |
| } |
| &Error::WaylandDeviceNew(ref e) => { |
| write!(f, "failed to create wayland device: {:?}", e) |
| } |
| &Error::LoadKernel(ref e) => write!(f, "failed to load kernel: {}", e), |
| } |
| } |
| } |
| |
| impl std::error::Error for Error { |
| fn description(&self) -> &str { |
| "Some device failure" |
| } |
| } |
| |
| type Result<T> = std::result::Result<T, Error>; |
| |
| // Verifies that |raw_fd| is actually owned by this process and duplicates it to ensure that |
| // we have a unique handle to it. |
| fn validate_raw_fd(raw_fd: RawFd) -> std::result::Result<RawFd, Box<error::Error>> { |
| // Checking that close-on-exec isn't set helps filter out FDs that were opened by |
| // crosvm as all crosvm FDs are close on exec. |
| // Safe because this doesn't modify any memory and we check the return value. |
| let flags = unsafe { libc::fcntl(raw_fd, libc::F_GETFD) }; |
| if flags < 0 || (flags & libc::FD_CLOEXEC) != 0 { |
| return Err(Box::new(Error::FailedCLOEXECCheck)); |
| } |
| |
| // Duplicate the fd to ensure that we don't accidentally close an fd previously |
| // opened by another subsystem. Safe because this doesn't modify any memory and |
| // we check the return value. |
| let dup_fd = unsafe { libc::fcntl(raw_fd, libc::F_DUPFD_CLOEXEC, 0) }; |
| if dup_fd < 0 { |
| return Err(Box::new(Error::FailedToDupFd)); |
| } |
| Ok(dup_fd as RawFd) |
| } |
| |
| fn create_base_minijail(root: &Path, seccomp_policy: &Path) -> Result<Minijail> { |
| // All child jails run in a new user namespace without any users mapped, |
| // they run as nobody unless otherwise configured. |
| let mut j = Minijail::new().map_err(|e| Error::DeviceJail(e))?; |
| j.namespace_pids(); |
| j.namespace_user(); |
| j.namespace_user_disable_setgroups(); |
| // Don't need any capabilities. |
| j.use_caps(0); |
| // Create a new mount namespace with an empty root FS. |
| j.namespace_vfs(); |
| j.enter_pivot_root(root) |
| .map_err(|e| Error::DevicePivotRoot(e))?; |
| // Run in an empty network namespace. |
| j.namespace_net(); |
| // Apply the block device seccomp policy. |
| j.no_new_privs(); |
| // Use TSYNC only for the side effect of it using SECCOMP_RET_TRAP, which will correctly kill |
| // the entire device process if a worker thread commits a seccomp violation. |
| j.set_seccomp_filter_tsync(); |
| #[cfg(debug_assertions)] |
| j.log_seccomp_filter_failures(); |
| j.parse_seccomp_filters(seccomp_policy) |
| .map_err(|e| Error::DeviceJail(e))?; |
| j.use_seccomp_filter(); |
| // Don't do init setup. |
| j.run_as_init(); |
| Ok(j) |
| } |
| |
| fn create_virtio_devs(cfg: VirtIoDeviceInfo, |
| mem: &GuestMemory, |
| _exit_evt: &EventFd, |
| wayland_device_socket: UnixDatagram, |
| balloon_device_socket: UnixDatagram) |
| -> std::result::Result<Vec<VirtioDeviceStub>, Box<error::Error>> { |
| static DEFAULT_PIVOT_ROOT: &'static str = "/var/empty"; |
| |
| let mut devs = Vec::new(); |
| |
| // An empty directory for jailed device's pivot root. |
| let empty_root_path = Path::new(DEFAULT_PIVOT_ROOT); |
| if cfg.multiprocess && !empty_root_path.exists() { |
| return Err(Box::new(Error::NoVarEmpty)); |
| } |
| |
| for disk in &cfg.disks { |
| // Special case '/proc/self/fd/*' paths. The FD is already open, just use it. |
| let mut raw_image: File = if disk.path.parent() == Some(Path::new("/proc/self/fd")) { |
| if !disk.path.is_file() { |
| return Err(Box::new(Error::InvalidFdPath)); |
| } |
| let raw_fd = disk.path.file_name() |
| .and_then(|fd_osstr| fd_osstr.to_str()) |
| .and_then(|fd_str| fd_str.parse::<c_int>().ok()) |
| .ok_or(Error::InvalidFdPath)?; |
| // Safe because we will validate |raw_fd|. |
| unsafe { File::from_raw_fd(validate_raw_fd(raw_fd)?) } |
| } else { |
| OpenOptions::new() |
| .read(true) |
| .write(!disk.read_only) |
| .open(&disk.path) |
| .map_err(|e| Error::Disk(e))? |
| }; |
| // Lock the disk image to prevent other crosvm instances from using it. |
| let lock_op = if disk.read_only { |
| FlockOperation::LockShared |
| } else { |
| FlockOperation::LockExclusive |
| }; |
| flock(&raw_image, lock_op, true).map_err(Error::DiskImageLock)?; |
| |
| let block_box: Box<devices::virtio::VirtioDevice> = match disk.disk_type { |
| DiskType::FlatFile => { // Access as a raw block device. |
| Box::new(devices::virtio::Block::new(raw_image, disk.read_only) |
| .map_err(|e| Error::BlockDeviceNew(e))?) |
| } |
| DiskType::Qcow => { // Valid qcow header present |
| let qcow_image = QcowFile::from(raw_image) |
| .map_err(|e| Error::QcowDeviceCreate(e))?; |
| Box::new(devices::virtio::Block::new(qcow_image, disk.read_only) |
| .map_err(|e| Error::BlockDeviceNew(e))?) |
| } |
| }; |
| let jail = if cfg.multiprocess { |
| let policy_path: PathBuf = cfg.seccomp_policy_dir.join("block_device.policy"); |
| Some(create_base_minijail(empty_root_path, &policy_path)?) |
| } |
| else { |
| None |
| }; |
| |
| devs.push(VirtioDeviceStub {dev: block_box, jail}); |
| } |
| |
| let rng_box = Box::new(devices::virtio::Rng::new().map_err(Error::RngDeviceNew)?); |
| let rng_jail = if cfg.multiprocess { |
| let policy_path: PathBuf = cfg.seccomp_policy_dir.join("rng_device.policy"); |
| Some(create_base_minijail(empty_root_path, &policy_path)?) |
| } else { |
| None |
| }; |
| devs.push(VirtioDeviceStub {dev: rng_box, jail: rng_jail}); |
| |
| let balloon_box = Box::new(devices::virtio::Balloon::new(balloon_device_socket) |
| .map_err(Error::BalloonDeviceNew)?); |
| let balloon_jail = if cfg.multiprocess { |
| let policy_path: PathBuf = cfg.seccomp_policy_dir.join("balloon_device.policy"); |
| Some(create_base_minijail(empty_root_path, &policy_path)?) |
| } else { |
| None |
| }; |
| devs.push(VirtioDeviceStub {dev: balloon_box, jail: balloon_jail}); |
| |
| // We checked above that if the IP is defined, then the netmask is, too. |
| if let Some(tap_fd) = cfg.tap_fd { |
| // Safe because we ensure that we get a unique handle to the fd. |
| let tap = unsafe { Tap::from_raw_fd(validate_raw_fd(tap_fd)?) }; |
| let net_box = Box::new(devices::virtio::Net::from(tap) |
| .map_err(|e| Error::NetDeviceNew(e))?); |
| |
| let jail = if cfg.multiprocess { |
| let policy_path: PathBuf = cfg.seccomp_policy_dir.join("net_device.policy"); |
| |
| Some(create_base_minijail(empty_root_path, &policy_path)?) |
| } else { |
| None |
| }; |
| |
| devs.push(VirtioDeviceStub {dev: net_box, jail}); |
| } else if let Some(host_ip) = cfg.host_ip { |
| if let Some(netmask) = cfg.netmask { |
| if let Some(mac_address) = cfg.mac_address { |
| let net_box: Box<devices::virtio::VirtioDevice> = if cfg.vhost_net { |
| Box::new(devices::virtio::vhost::Net::<Tap, vhost::Net<Tap>>::new(host_ip, |
| netmask, |
| mac_address, |
| &mem) |
| .map_err(|e| Error::VhostNetDeviceNew(e))?) |
| } else { |
| Box::new(devices::virtio::Net::<Tap>::new(host_ip, netmask, mac_address) |
| .map_err(|e| Error::NetDeviceNew(e))?) |
| }; |
| |
| let jail = if cfg.multiprocess { |
| let policy_path: PathBuf = if cfg.vhost_net { |
| cfg.seccomp_policy_dir.join("vhost_net_device.policy") |
| } else { |
| cfg.seccomp_policy_dir.join("net_device.policy") |
| }; |
| |
| Some(create_base_minijail(empty_root_path, &policy_path)?) |
| } else { |
| None |
| }; |
| |
| devs.push(VirtioDeviceStub {dev: net_box, jail}); |
| } |
| } |
| } |
| |
| if let Some(wayland_socket_path) = cfg.wayland_socket_path.as_ref() { |
| let jailed_wayland_path = Path::new("/wayland-0"); |
| |
| let wl_box = Box::new(devices::virtio::Wl::new(if cfg.multiprocess { |
| &jailed_wayland_path |
| } else { |
| wayland_socket_path.as_path() |
| }, |
| wayland_device_socket) |
| .map_err(Error::WaylandDeviceNew)?); |
| |
| let jail = if cfg.multiprocess { |
| let policy_path: PathBuf = cfg.seccomp_policy_dir.join("wl_device.policy"); |
| let mut jail = create_base_minijail(empty_root_path, &policy_path)?; |
| |
| // Create a tmpfs in the device's root directory so that we can bind mount the |
| // wayland socket into it. The size=67108864 is size=64*1024*1024 or size=64MB. |
| jail.mount_with_data(Path::new("none"), Path::new("/"), "tmpfs", |
| (libc::MS_NOSUID | libc::MS_NODEV | libc::MS_NOEXEC) as usize, |
| "size=67108864") |
| .unwrap(); |
| |
| // Bind mount the wayland socket into jail's root. This is necessary since each |
| // new wayland context must open() the socket. |
| jail.mount_bind(wayland_socket_path.as_path(), jailed_wayland_path, true) |
| .unwrap(); |
| |
| // Set the uid/gid for the jailed process, and give a basic id map. This |
| // is required for the above bind mount to work. |
| let crosvm_user_group = CStr::from_bytes_with_nul(b"crosvm\0").unwrap(); |
| let crosvm_uid = match get_user_id(&crosvm_user_group) { |
| Ok(u) => u, |
| Err(e) => { |
| warn!("falling back to current user id for Wayland: {:?}", e); |
| geteuid() |
| } |
| }; |
| let crosvm_gid = match get_group_id(&crosvm_user_group) { |
| Ok(u) => u, |
| Err(e) => { |
| warn!("falling back to current group id for Wayland: {:?}", e); |
| getegid() |
| } |
| }; |
| jail.change_uid(crosvm_uid); |
| jail.change_gid(crosvm_gid); |
| jail.uidmap(&format!("{0} {0} 1", crosvm_uid)) |
| .map_err(Error::SettingUidMap)?; |
| jail.gidmap(&format!("{0} {0} 1", crosvm_gid)) |
| .map_err(Error::SettingGidMap)?; |
| |
| Some(jail) |
| } else { |
| None |
| }; |
| devs.push(VirtioDeviceStub { |
| dev: wl_box, |
| jail, |
| }); |
| } |
| |
| if let Some(cid) = cfg.cid { |
| let vsock_box = Box::new(devices::virtio::vhost::Vsock::new(cid, &mem) |
| .map_err(Error::VhostVsockDeviceNew)?); |
| |
| let jail = if cfg.multiprocess { |
| let policy_path: PathBuf = cfg.seccomp_policy_dir.join("vhost_vsock_device.policy"); |
| |
| Some(create_base_minijail(empty_root_path, &policy_path)?) |
| } else { |
| None |
| }; |
| |
| devs.push(VirtioDeviceStub {dev: vsock_box, jail}); |
| } |
| |
| #[cfg(feature = "gpu")] |
| { |
| if cfg.gpu { |
| if let Some(wayland_socket_path) = cfg.wayland_socket_path.as_ref() { |
| let jailed_wayland_path = Path::new("/wayland-0"); |
| |
| let gpu_box = |
| Box::new(devices::virtio::Gpu::new(_exit_evt |
| .try_clone() |
| .map_err(Error::CloneEventFd)?, |
| if cfg.multiprocess { |
| &jailed_wayland_path |
| } else { |
| wayland_socket_path.as_path() |
| })); |
| |
| let jail = if cfg.multiprocess { |
| let policy_path: PathBuf = cfg.seccomp_policy_dir.join("gpu_device.policy"); |
| let mut jail = create_base_minijail(empty_root_path, &policy_path)?; |
| |
| // Create a tmpfs in the device's root directory so that we can bind mount the |
| // dri directory into it. The size=67108864 is size=64*1024*1024 or size=64MB. |
| jail.mount_with_data(Path::new("none"), Path::new("/"), "tmpfs", |
| (libc::MS_NOSUID | libc::MS_NODEV | |
| libc::MS_NOEXEC) as usize, |
| "size=67108864") |
| .unwrap(); |
| |
| // Device nodes required for DRM. |
| let sys_dev_char_path = Path::new("/sys/dev/char"); |
| jail.mount_bind(sys_dev_char_path, sys_dev_char_path, false) |
| .unwrap(); |
| let sys_devices_path = Path::new("/sys/devices"); |
| jail.mount_bind(sys_devices_path, sys_devices_path, false) |
| .unwrap(); |
| let drm_dri_path = Path::new("/dev/dri"); |
| jail.mount_bind(drm_dri_path, drm_dri_path, false) |
| .unwrap(); |
| |
| // Libraries that are required when mesa drivers are dynamically loaded. |
| let lib_path = Path::new("/lib64"); |
| jail.mount_bind(lib_path, lib_path, false) |
| .unwrap(); |
| let usr_lib_path = Path::new("/usr/lib64"); |
| jail.mount_bind(usr_lib_path, usr_lib_path, false) |
| .unwrap(); |
| |
| // Bind mount the wayland socket into jail's root. This is necessary since each |
| // new wayland context must open() the socket. |
| jail.mount_bind(wayland_socket_path.as_path(), jailed_wayland_path, true) |
| .unwrap(); |
| |
| // Set the uid/gid for the jailed process, and give a basic id map. This |
| // is required for the above bind mount to work. |
| let crosvm_user_group = CStr::from_bytes_with_nul(b"crosvm\0").unwrap(); |
| let crosvm_uid = match get_user_id(&crosvm_user_group) { |
| Ok(u) => u, |
| Err(e) => { |
| warn!("falling back to current user id for gpu: {:?}", e); |
| geteuid() |
| } |
| }; |
| let crosvm_gid = match get_group_id(&crosvm_user_group) { |
| Ok(u) => u, |
| Err(e) => { |
| warn!("falling back to current group id for gpu: {:?}", e); |
| getegid() |
| } |
| }; |
| jail.change_uid(crosvm_uid); |
| jail.change_gid(crosvm_gid); |
| jail.uidmap(&format!("{0} {0} 1", crosvm_uid)) |
| .map_err(Error::SettingUidMap)?; |
| jail.gidmap(&format!("{0} {0} 1", crosvm_gid)) |
| .map_err(Error::SettingGidMap)?; |
| |
| Some(jail) |
| } else { |
| None |
| }; |
| devs.push(VirtioDeviceStub {dev: gpu_box, jail}); |
| } |
| } |
| } |
| |
| let chronos_user_group = CStr::from_bytes_with_nul(b"chronos\0").unwrap(); |
| let chronos_uid = match get_user_id(&chronos_user_group) { |
| Ok(u) => u, |
| Err(e) => { |
| warn!("falling back to current user id for 9p: {:?}", e); |
| geteuid() |
| } |
| }; |
| let chronos_gid = match get_group_id(&chronos_user_group) { |
| Ok(u) => u, |
| Err(e) => { |
| warn!("falling back to current group id for 9p: {:?}", e); |
| getegid() |
| } |
| }; |
| |
| for &(ref src, ref tag) in &cfg.shared_dirs { |
| let (jail, root) = if cfg.multiprocess { |
| let policy_path: PathBuf = cfg.seccomp_policy_dir.join("9p_device.policy"); |
| let mut jail = create_base_minijail(empty_root_path, &policy_path)?; |
| |
| // The shared directory becomes the root of the device's file system. |
| let root = Path::new("/"); |
| jail.mount_bind(&src, root, true).unwrap(); |
| |
| // Set the uid/gid for the jailed process, and give a basic id map. This |
| // is required for the above bind mount to work. |
| jail.change_uid(chronos_uid); |
| jail.change_gid(chronos_gid); |
| jail.uidmap(&format!("{0} {0} 1", chronos_uid)) |
| .map_err(Error::SettingUidMap)?; |
| jail.gidmap(&format!("{0} {0} 1", chronos_gid)) |
| .map_err(Error::SettingGidMap)?; |
| |
| (Some(jail), root) |
| } else { |
| // There's no bind mount so we tell the server to treat the source directory as the |
| // root. The double deref here converts |src| from a &PathBuf into a &Path. |
| (None, &**src) |
| }; |
| |
| let p9_box = Box::new(devices::virtio::P9::new(root, tag).map_err(Error::P9DeviceNew)?); |
| |
| devs.push(VirtioDeviceStub {dev: p9_box, jail}); |
| } |
| |
| Ok(devs) |
| } |
| |
| fn setup_vcpu_signal_handler() -> Result<()> { |
| unsafe { |
| extern "C" fn handle_signal() {} |
| // Our signal handler does nothing and is trivially async signal safe. |
| register_signal_handler(SIGRTMIN() + 0, handle_signal) |
| .map_err(Error::RegisterSignalHandler)?; |
| } |
| block_signal(SIGRTMIN() + 0).map_err(Error::BlockSignal)?; |
| Ok(()) |
| } |
| |
| fn run_vcpu(vcpu: Vcpu, |
| cpu_id: u32, |
| start_barrier: Arc<Barrier>, |
| io_bus: devices::Bus, |
| mmio_bus: devices::Bus, |
| exit_evt: EventFd, |
| kill_signaled: Arc<AtomicBool>) -> Result<JoinHandle<()>> { |
| thread::Builder::new() |
| .name(format!("crosvm_vcpu{}", cpu_id)) |
| .spawn(move || { |
| let mut sig_ok = true; |
| match get_blocked_signals() { |
| Ok(mut v) => { |
| v.retain(|&x| x != SIGRTMIN() + 0); |
| if let Err(e) = vcpu.set_signal_mask(&v) { |
| error!( |
| "Failed to set the KVM_SIGNAL_MASK for vcpu {} : {:?}", |
| cpu_id, e |
| ); |
| sig_ok = false; |
| } |
| } |
| Err(e) => { |
| error!( |
| "Failed to retrieve signal mask for vcpu {} : {:?}", |
| cpu_id, e |
| ); |
| sig_ok = false; |
| } |
| }; |
| |
| start_barrier.wait(); |
| |
| while sig_ok { |
| let run_res = vcpu.run(); |
| match run_res { |
| Ok(run) => { |
| match run { |
| VcpuExit::IoIn(addr, data) => { |
| io_bus.read(addr as u64, data); |
| } |
| VcpuExit::IoOut(addr, data) => { |
| io_bus.write(addr as u64, data); |
| } |
| VcpuExit::MmioRead(addr, data) => { |
| mmio_bus.read(addr, data); |
| } |
| VcpuExit::MmioWrite(addr, data) => { |
| mmio_bus.write(addr, data); |
| } |
| VcpuExit::Hlt => break, |
| VcpuExit::Shutdown => break, |
| VcpuExit::SystemEvent(_, _) => |
| //TODO handle reboot and crash events |
| kill_signaled.store(true, Ordering::SeqCst), |
| r => warn!("unexpected vcpu exit: {:?}", r), |
| } |
| } |
| Err(e) => { |
| match e.errno() { |
| libc::EAGAIN | libc::EINTR => {}, |
| _ => { |
| error!("vcpu hit unknown error: {:?}", e); |
| break; |
| } |
| } |
| } |
| } |
| if kill_signaled.load(Ordering::SeqCst) { |
| break; |
| } |
| |
| // Try to clear the signal that we use to kick VCPU if it is |
| // pending before attempting to handle pause requests. |
| clear_signal(SIGRTMIN() + 0).expect("failed to clear pending signal"); |
| } |
| exit_evt |
| .write(1) |
| .expect("failed to signal vcpu exit eventfd"); |
| }) |
| .map_err(Error::SpawnVcpu) |
| } |
| |
| // Reads the contents of a file and converts them into a u64. |
| fn file_to_u64<P: AsRef<Path>>(path: P) -> io::Result<u64> { |
| let mut file = File::open(path)?; |
| |
| let mut buf = [0u8; 32]; |
| let count = file.read(&mut buf)?; |
| |
| let content = str::from_utf8(&buf[..count]) |
| .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?; |
| content.trim().parse().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e)) |
| } |
| |
| pub fn run_config(cfg: Config) -> Result<()> { |
| if cfg.virtio_dev_info.multiprocess { |
| // Printing something to the syslog before entering minijail so that libc's syslogger has a |
| // chance to open files necessary for its operation, like `/etc/localtime`. After jailing, |
| // access to those files will not be possible. |
| info!("crosvm entering multiprocess mode"); |
| } |
| |
| let pci_devices = devices::PciDeviceList::new(); |
| |
| // Masking signals is inherently dangerous, since this can persist across clones/execs. Do this |
| // before any jailed devices have been spawned, so that we can catch any of them that fail very |
| // quickly. |
| let sigchld_fd = SignalFd::new(libc::SIGCHLD).map_err(Error::CreateSignalFd)?; |
| |
| let components = VmComponents { |
| pci_devices, |
| memory_mb: (cfg.memory.unwrap_or(256) << 20) as u64, |
| vcpu_count: cfg.vcpu_count.unwrap_or(1), |
| kernel_image: File::open(cfg.kernel_path.as_path()) |
| .map_err(|e| Error::OpenKernel(cfg.kernel_path.clone(), e))?, |
| extra_kernel_params: cfg.params, |
| wayland_dmabuf: cfg.virtio_dev_info.wayland_dmabuf, |
| }; |
| |
| let mut control_sockets = Vec::new(); |
| if let Some(ref path_string) = cfg.socket_path { |
| let path = Path::new(path_string); |
| let dgram = UnixDatagram::bind(path).map_err(Error::CreateSocket)?; |
| control_sockets.push(UnlinkUnixDatagram(dgram)); |
| }; |
| let (wayland_host_socket, wayland_device_socket) = UnixDatagram::pair() |
| .map_err(Error::CreateSocket)?; |
| control_sockets.push(UnlinkUnixDatagram(wayland_host_socket)); |
| // Balloon gets a special socket so balloon requests can be forwarded from the main process. |
| let (balloon_host_socket, balloon_device_socket) = UnixDatagram::pair() |
| .map_err(Error::CreateSocket)?; |
| |
| let virtio_dev_info = cfg.virtio_dev_info; |
| let linux = Arch::build_vm(components, |
| |m, e| create_virtio_devs(virtio_dev_info, m, e, |
| wayland_device_socket, |
| balloon_device_socket)) |
| .map_err(Error::BuildingVm)?; |
| run_control(linux, control_sockets, balloon_host_socket, sigchld_fd) |
| } |
| |
| fn run_control(mut linux: RunnableLinuxVm, |
| control_sockets: Vec<UnlinkUnixDatagram>, |
| balloon_host_socket: UnixDatagram, |
| sigchld_fd: SignalFd) -> Result<()> { |
| const MAX_VM_FD_RECV: usize = 1; |
| |
| // Paths to get the currently available memory and the low memory threshold. |
| const LOWMEM_MARGIN: &'static str = "/sys/kernel/mm/chromeos-low_mem/margin"; |
| const LOWMEM_AVAILABLE: &'static str = "/sys/kernel/mm/chromeos-low_mem/available"; |
| |
| // The amount of additional memory to claim back from the VM whenever the system is |
| // low on memory. |
| const ONE_GB: u64 = (1 << 30); |
| |
| let max_balloon_memory = match linux.vm.get_memory().memory_size() { |
| // If the VM has at least 1.5 GB, the balloon driver can consume all but the last 1 GB. |
| n if n >= (ONE_GB / 2) * 3 => n - ONE_GB, |
| // Otherwise, if the VM has at least 500MB the balloon driver will consume at most |
| // half of it. |
| n if n >= (ONE_GB / 2) => n / 2, |
| // Otherwise, the VM is too small for us to take memory away from it. |
| _ => 0, |
| }; |
| let mut current_balloon_memory: u64 = 0; |
| let balloon_memory_increment: u64 = max_balloon_memory / 16; |
| |
| #[derive(PollToken)] |
| enum Token { |
| Exit, |
| Stdin, |
| ChildSignal, |
| CheckAvailableMemory, |
| LowMemory, |
| LowmemTimer, |
| VmControl { index: usize }, |
| } |
| |
| let stdin_handle = stdin(); |
| let stdin_lock = stdin_handle.lock(); |
| stdin_lock |
| .set_raw_mode() |
| .expect("failed to set terminal raw mode"); |
| |
| let poll_ctx = PollContext::new().map_err(Error::CreatePollContext)?; |
| poll_ctx.add(&linux.exit_evt, Token::Exit).map_err(Error::PollContextAdd)?; |
| if let Err(e) = poll_ctx.add(&stdin_handle, Token::Stdin) { |
| warn!("failed to add stdin to poll context: {:?}", e); |
| } |
| poll_ctx.add(&sigchld_fd, Token::ChildSignal).map_err(Error::PollContextAdd)?; |
| for (index, socket) in control_sockets.iter().enumerate() { |
| poll_ctx.add(socket.as_ref(), Token::VmControl{ index }).map_err(Error::PollContextAdd)?; |
| } |
| |
| // Watch for low memory notifications and take memory back from the VM. |
| let low_mem = File::open("/dev/chromeos-low-mem").ok(); |
| if let Some(ref low_mem) = low_mem { |
| poll_ctx.add(low_mem, Token::LowMemory).map_err(Error::PollContextAdd)?; |
| } else { |
| warn!("Unable to open low mem indicator, maybe not a chrome os kernel"); |
| } |
| |
| // Used to rate limit balloon requests. |
| let mut lowmem_timer = TimerFd::new().map_err(Error::CreateTimerFd)?; |
| poll_ctx.add(&lowmem_timer, Token::LowmemTimer).map_err(Error::PollContextAdd)?; |
| |
| // Used to check whether it's ok to start giving memory back to the VM. |
| let mut freemem_timer = TimerFd::new().map_err(Error::CreateTimerFd)?; |
| poll_ctx.add(&freemem_timer, Token::CheckAvailableMemory).map_err(Error::PollContextAdd)?; |
| |
| // Used to add jitter to timer values so that we don't have a thundering herd problem when |
| // multiple VMs are running. |
| let mut rng = thread_rng(); |
| let lowmem_jitter_ms = Range::new(0, 200); |
| let freemem_jitter_secs = Range::new(0, 12); |
| let interval_jitter_secs = Range::new(0, 6); |
| |
| let mut vcpu_handles = Vec::with_capacity(linux.vcpus.len() as usize); |
| let vcpu_thread_barrier = Arc::new(Barrier::new((linux.vcpus.len() + 1) as usize)); |
| let kill_signaled = Arc::new(AtomicBool::new(false)); |
| setup_vcpu_signal_handler()?; |
| for (cpu_id, vcpu) in linux.vcpus.into_iter().enumerate() { |
| let handle = run_vcpu(vcpu, |
| cpu_id as u32, |
| vcpu_thread_barrier.clone(), |
| linux.io_bus.clone(), |
| linux.mmio_bus.clone(), |
| linux.exit_evt.try_clone().map_err(Error::CloneEventFd)?, |
| kill_signaled.clone())?; |
| vcpu_handles.push(handle); |
| } |
| vcpu_thread_barrier.wait(); |
| |
| let mut scm = Scm::new(MAX_VM_FD_RECV); |
| |
| 'poll: loop { |
| let events = { |
| match poll_ctx.wait() { |
| Ok(v) => v, |
| Err(e) => { |
| error!("failed to poll: {:?}", e); |
| break; |
| } |
| } |
| }; |
| for event in events.iter_readable() { |
| match event.token() { |
| Token::Exit => { |
| info!("vcpu requested shutdown"); |
| break 'poll; |
| } |
| Token::Stdin => { |
| let mut out = [0u8; 64]; |
| match stdin_lock.read_raw(&mut out[..]) { |
| Ok(0) => { |
| // Zero-length read indicates EOF. Remove from pollables. |
| let _ = poll_ctx.delete(&stdin_handle); |
| }, |
| Err(e) => { |
| warn!("error while reading stdin: {:?}", e); |
| let _ = poll_ctx.delete(&stdin_handle); |
| }, |
| Ok(count) => { |
| linux.stdio_serial |
| .lock() |
| .unwrap() |
| .queue_input_bytes(&out[..count]) |
| .expect("failed to queue bytes into serial port"); |
| }, |
| } |
| } |
| Token::ChildSignal => { |
| // Print all available siginfo structs, then exit the loop. |
| loop { |
| let result = sigchld_fd.read().map_err(Error::SignalFd)?; |
| if let Some(siginfo) = result { |
| error!("child {} died: signo {}, status {}, code {}", |
| siginfo.ssi_pid, |
| siginfo.ssi_signo, |
| siginfo.ssi_status, |
| siginfo.ssi_code); |
| } |
| break 'poll; |
| } |
| } |
| Token::CheckAvailableMemory => { |
| // Acknowledge the timer. |
| freemem_timer.wait().map_err(Error::TimerFd)?; |
| if current_balloon_memory == 0 { |
| // Nothing to see here. |
| if let Err(e) = freemem_timer.clear() { |
| warn!("unable to clear available memory check timer: {}", e); |
| } |
| continue; |
| } |
| |
| // Otherwise see if we can free up some memory. |
| let margin = file_to_u64(LOWMEM_MARGIN).map_err(Error::ReadLowmemMargin)?; |
| let available = file_to_u64(LOWMEM_AVAILABLE).map_err(Error::ReadLowmemAvailable)?; |
| |
| // `available` and `margin` are specified in MB while `balloon_memory_increment` is in |
| // bytes. So to correctly compare them we need to turn the increment value into MB. |
| if available >= margin + 2*(balloon_memory_increment >> 20) { |
| current_balloon_memory = if current_balloon_memory >= balloon_memory_increment { |
| current_balloon_memory - balloon_memory_increment |
| } else { |
| 0 |
| }; |
| let mut buf = [0u8; mem::size_of::<u64>()]; |
| LittleEndian::write_u64(&mut buf, current_balloon_memory); |
| if let Err(e) = balloon_host_socket.send(&buf) { |
| warn!("failed to send memory value to balloon device: {}", e); |
| } |
| } |
| } |
| Token::LowMemory => { |
| if let Some(ref low_mem) = low_mem { |
| let old_balloon_memory = current_balloon_memory; |
| current_balloon_memory = |
| min(current_balloon_memory + balloon_memory_increment, |
| max_balloon_memory); |
| if current_balloon_memory != old_balloon_memory { |
| let mut buf = [0u8; mem::size_of::<u64>()]; |
| LittleEndian::write_u64(&mut buf, current_balloon_memory); |
| if let Err(e) = balloon_host_socket.send(&buf) { |
| warn!("failed to send memory value to balloon device: {}", e); |
| } |
| } |
| |
| // Stop polling the lowmem device until the timer fires. |
| poll_ctx.delete(low_mem).map_err(Error::PollContextDelete)?; |
| |
| // Add some jitter to the timer so that if there are multiple VMs running |
| // they don't all start ballooning at exactly the same time. |
| let lowmem_dur = |
| Duration::from_millis(1000 + lowmem_jitter_ms.ind_sample(&mut rng)); |
| lowmem_timer.reset(lowmem_dur, None).map_err(Error::ResetTimerFd)?; |
| |
| // Also start a timer to check when we can start giving memory back. Do the |
| // first check after a minute (with jitter) and subsequent checks after |
| // every 30 seconds (with jitter). |
| let freemem_dur = |
| Duration::from_secs(60 + freemem_jitter_secs.ind_sample(&mut rng)); |
| let freemem_int = |
| Duration::from_secs(30 + interval_jitter_secs.ind_sample(&mut rng)); |
| freemem_timer |
| .reset(freemem_dur, Some(freemem_int)) |
| .map_err(Error::ResetTimerFd)?; |
| } |
| } |
| Token::LowmemTimer => { |
| // Acknowledge the timer. |
| lowmem_timer.wait().map_err(Error::TimerFd)?; |
| |
| if let Some(ref low_mem) = low_mem { |
| // Start polling the lowmem device again. |
| poll_ctx.add(low_mem, Token::LowMemory).map_err(Error::PollContextAdd)?; |
| } |
| } |
| Token::VmControl { index } => { |
| if let Some(socket) = control_sockets.get(index as usize) { |
| match VmRequest::recv(&mut scm, socket.as_ref()) { |
| Ok(request) => { |
| let mut running = true; |
| let response = |
| request.execute(&mut linux.vm, |
| &mut linux.resources, |
| &mut running, |
| &balloon_host_socket); |
| if let Err(e) = response.send(&mut scm, socket.as_ref()) { |
| error!("failed to send VmResponse: {:?}", e); |
| } |
| if !running { |
| info!("control socket requested exit"); |
| break 'poll; |
| } |
| } |
| Err(e) => error!("failed to recv VmRequest: {:?}", e), |
| } |
| } |
| } |
| } |
| } |
| for event in events.iter_hungup() { |
| // It's possible more data is readable and buffered while the socket is hungup, so |
| // don't delete the socket from the poll context until we're sure all the data is |
| // read. |
| if !event.readable() { |
| match event.token() { |
| Token::Exit => {}, |
| Token::Stdin => { |
| let _ = poll_ctx.delete(&stdin_handle); |
| }, |
| Token::ChildSignal => {}, |
| Token::CheckAvailableMemory => {}, |
| Token::LowMemory => {}, |
| Token::LowmemTimer => {}, |
| Token::VmControl { index } => { |
| if let Some(socket) = control_sockets.get(index as usize) { |
| let _ = poll_ctx.delete(socket.as_ref()); |
| } |
| }, |
| } |
| } |
| } |
| } |
| |
| // vcpu threads MUST see the kill signaled flag, otherwise they may |
| // re-enter the VM. |
| kill_signaled.store(true, Ordering::SeqCst); |
| for handle in vcpu_handles { |
| match handle.kill(SIGRTMIN() + 0) { |
| Ok(_) => { |
| if let Err(e) = handle.join() { |
| error!("failed to join vcpu thread: {:?}", e); |
| } |
| } |
| Err(e) => error!("failed to kill vcpu thread: {:?}", e), |
| } |
| } |
| |
| stdin_lock |
| .set_canon_mode() |
| .expect("failed to restore canonical mode for terminal"); |
| |
| Ok(()) |
| } |