// Copyright 2018 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::collections::hash_map::{Entry, HashMap, VacantEntry}; use std::env::set_var; use std::fs::File; use std::io::{IoSlice, Write}; use std::mem::transmute; use std::os::unix::net::UnixDatagram; use std::path::Path; use std::process::Command; use std::sync::{Arc, RwLock}; use std::thread::JoinHandle; use net_util::Error as NetError; use libc::{pid_t, waitpid, EINVAL, ENODATA, ENOTTY, WEXITSTATUS, WIFEXITED, WNOHANG, WTERMSIG}; use protobuf::Message; use base::{ error, AsRawDescriptor, Error as SysError, Event, IntoRawDescriptor, Killable, MemoryMappingBuilder, RawDescriptor, Result as SysResult, ScmSocket, SharedMemory, SharedMemoryUnix, SIGRTMIN, }; use kvm::{dirty_log_bitmap_size, Datamatch, IoeventAddress, IrqRoute, IrqSource, PicId, Vm}; use kvm_sys::{kvm_clock_data, kvm_ioapic_state, kvm_pic_state, kvm_pit_state2}; use minijail::Minijail; use protos::plugin::*; use sync::Mutex; use vm_memory::GuestAddress; use super::*; // Wrapper types to make the kvm state structs DataInit use data_model::DataInit; #[derive(Copy, Clone)] struct VmPicState(kvm_pic_state); unsafe impl DataInit for VmPicState {} #[derive(Copy, Clone)] struct VmIoapicState(kvm_ioapic_state); unsafe impl DataInit for VmIoapicState {} #[derive(Copy, Clone)] struct VmPitState(kvm_pit_state2); unsafe impl DataInit for VmPitState {} #[derive(Copy, Clone)] struct VmClockState(kvm_clock_data); unsafe impl DataInit for VmClockState {} fn get_vm_state(vm: &Vm, state_set: MainRequest_StateSet) -> SysResult> { Ok(match state_set { MainRequest_StateSet::PIC0 => VmPicState(vm.get_pic_state(PicId::Primary)?) .as_slice() .to_vec(), MainRequest_StateSet::PIC1 => VmPicState(vm.get_pic_state(PicId::Secondary)?) .as_slice() .to_vec(), MainRequest_StateSet::IOAPIC => VmIoapicState(vm.get_ioapic_state()?).as_slice().to_vec(), MainRequest_StateSet::PIT => VmPitState(vm.get_pit_state()?).as_slice().to_vec(), MainRequest_StateSet::CLOCK => VmClockState(vm.get_clock()?).as_slice().to_vec(), }) } fn set_vm_state(vm: &Vm, state_set: MainRequest_StateSet, state: &[u8]) -> SysResult<()> { match state_set { MainRequest_StateSet::PIC0 => vm.set_pic_state( PicId::Primary, &VmPicState::from_slice(state) .ok_or(SysError::new(EINVAL))? .0, ), MainRequest_StateSet::PIC1 => vm.set_pic_state( PicId::Secondary, &VmPicState::from_slice(state) .ok_or(SysError::new(EINVAL))? .0, ), MainRequest_StateSet::IOAPIC => vm.set_ioapic_state( &VmIoapicState::from_slice(state) .ok_or(SysError::new(EINVAL))? .0, ), MainRequest_StateSet::PIT => vm.set_pit_state( &VmPitState::from_slice(state) .ok_or(SysError::new(EINVAL))? .0, ), MainRequest_StateSet::CLOCK => vm.set_clock( &VmClockState::from_slice(state) .ok_or(SysError::new(EINVAL))? .0, ), } } /// The status of a process, either that it is running, or that it exited under some condition. pub enum ProcessStatus { /// The process is running and therefore has no information about its result. Running, /// The process has exited with a successful code. Success, /// The process failed with the given exit code. Fail(i32), /// The process was terminated with the given signal code. Signal(i32), } /// Creates, owns, and handles messages from a plugin process. /// /// A plugin process has control over a single VM and a fixed number of VCPUs via a set of pipes & unix /// domain socket connections and a protocol defined in `protos::plugin`. The plugin process is run /// in an unprivileged manner as a child process spawned via a path to a arbitrary executable. pub struct Process { started: bool, plugin_pid: pid_t, request_sockets: Vec, objects: HashMap, shared_vcpu_state: Arc>, per_vcpu_states: Vec>>, // Resource to sent to plugin kill_evt: Event, vcpu_pipes: Vec, // Socket Transmission request_buffer: Vec, response_buffer: Vec, } impl Process { /// Creates a new plugin process for the given number of vcpus and VM. /// /// This will immediately spawn the plugin process and wait for the child to signal that it is /// ready to start. This call may block indefinitely. /// /// Set the `jail` argument to spawn the plugin process within the preconfigured jail. /// Due to an API limitation in libminijail necessitating that this function set an environment /// variable, this function is not thread-safe. pub fn new( cpu_count: u32, cmd: &Path, args: &[&str], jail: Option, ) -> Result { let (request_socket, child_socket) = new_seqpacket_pair().map_err(Error::CreateMainSocket)?; let mut vcpu_pipes: Vec = Vec::with_capacity(cpu_count as usize); for _ in 0..cpu_count { vcpu_pipes.push(new_pipe_pair().map_err(Error::CreateVcpuSocket)?); } let mut per_vcpu_states: Vec>> = Vec::with_capacity(cpu_count as usize); // TODO(zachr): replace with `resize_default` when that stabilizes. Using a plain `resize` // is incorrect because each element in the `Vec` will contain a shared reference to the // same `PerVcpuState` instance. This happens because `resize` fills new slots using clones // of the instance given to `resize`. for _ in 0..cpu_count { per_vcpu_states.push(Default::default()); } let plugin_pid = match jail { Some(jail) => { set_var( "CROSVM_SOCKET", child_socket.as_raw_descriptor().to_string(), ); jail.run(cmd, &[0, 1, 2, child_socket.as_raw_descriptor()], args) .map_err(Error::PluginRunJail)? } None => Command::new(cmd) .args(args) .env( "CROSVM_SOCKET", child_socket.as_raw_descriptor().to_string(), ) .spawn() .map_err(Error::PluginSpawn)? .id() as pid_t, }; Ok(Process { started: false, plugin_pid, request_sockets: vec![request_socket], objects: Default::default(), shared_vcpu_state: Default::default(), per_vcpu_states, kill_evt: Event::new().map_err(Error::CreateEvent)?, vcpu_pipes, request_buffer: vec![0; MAX_DATAGRAM_SIZE], response_buffer: Vec::new(), }) } /// Creates a VCPU plugin connection object, used by a VCPU run loop to communicate with the /// plugin process. /// /// While each invocation of `create_vcpu` with the given `cpu_id` will return a unique /// `PluginVcpu` object, the underlying resources are shared by each `PluginVcpu` resulting from /// the same `cpu_id`. pub fn create_vcpu(&self, cpu_id: u32) -> Result { let vcpu_pipe_read = self.vcpu_pipes[cpu_id as usize] .crosvm_read .try_clone() .map_err(Error::CloneVcpuPipe)?; let vcpu_pipe_write = self.vcpu_pipes[cpu_id as usize] .crosvm_write .try_clone() .map_err(Error::CloneVcpuPipe)?; Ok(PluginVcpu::new( self.shared_vcpu_state.clone(), self.per_vcpu_states[cpu_id as usize].clone(), vcpu_pipe_read, vcpu_pipe_write, )) } /// Returns if the plugin process indicated the VM was ready to start. pub fn is_started(&self) -> bool { self.started } /// Returns the process ID of the plugin process. pub fn pid(&self) -> pid_t { self.plugin_pid } /// Returns a slice of each socket that should be polled. /// /// If any socket in this slice becomes readable, `handle_socket` should be called with the /// index of that socket. If any socket becomes closed, its index should be passed to /// `drop_sockets`. pub fn sockets(&self) -> &[UnixDatagram] { &self.request_sockets } /// Drops the each socket identified by its index in the slice returned by `sockets`. /// /// The given `socket_idxs` slice will be modified in an arbitrary way for efficient removal of /// the sockets from internal data structures. pub fn drop_sockets(&mut self, socket_idxs: &mut [usize]) { // Takes a mutable slice so that the indices can be sorted for efficient removal in // request_sockets.. socket_idxs.sort_unstable_by(|a, b| b.cmp(a)); let old_len = self.request_sockets.len(); for &socket_index in socket_idxs.iter() { // swap_remove changes the index of the last element, but we already know that one // doesn't need to be removed because we are removing sockets in descending order thanks // to the above sort. self.request_sockets.swap_remove(socket_index); } assert_eq!(old_len - socket_idxs.len(), self.request_sockets.len()); } /// Gently requests that the plugin process exit cleanly, and ends handling of all VCPU /// connections. /// /// The plugin process can ignore the given signal, and so some timeout should be used before /// forcefully terminating the process. /// /// Any blocked VCPU connections will get interrupted so that the VCPU threads can exit cleanly. /// Any subsequent attempt to use the VCPU connections will fail. pub fn signal_kill(&mut self) -> SysResult<()> { self.kill_evt.write(1)?; // Normally we'd get any blocked recv() calls in the VCPU threads // to unblock by calling shutdown(). However, we're using pipes // (for improved performance), and pipes don't have shutdown so // instead we'll write a shutdown message to ourselves using the // the writable side of the pipe (normally used by the plugin). for pipe in self.vcpu_pipes.iter_mut() { let mut shutdown_request = VcpuRequest::new(); shutdown_request.set_shutdown(VcpuRequest_Shutdown::new()); let mut buffer = Vec::new(); shutdown_request .write_to_vec(&mut buffer) .map_err(proto_to_sys_err)?; pipe.plugin_write .write(&buffer[..]) .map_err(io_to_sys_err)?; } Ok(()) } /// Waits without blocking for the plugin process to exit and returns the status. pub fn try_wait(&mut self) -> SysResult { let mut status = 0; // Safe because waitpid is given a valid pointer of correct size and mutability, and the // return value is checked. let ret = unsafe { waitpid(self.plugin_pid, &mut status, WNOHANG) }; match ret { -1 => Err(SysError::last()), 0 => Ok(ProcessStatus::Running), _ => { if WIFEXITED(status) { match WEXITSTATUS(status) { 0 => Ok(ProcessStatus::Success), code => Ok(ProcessStatus::Fail(code)), } } else { // Plugin terminated but has no exit status, so it must have been signaled. Ok(ProcessStatus::Signal(WTERMSIG(status))) } } } } fn handle_io_event( entry: VacantEntry, vm: &mut Vm, io_event: &MainRequest_Create_IoEvent, ) -> SysResult { let evt = Event::new()?; let addr = match io_event.space { AddressSpace::IOPORT => IoeventAddress::Pio(io_event.address), AddressSpace::MMIO => IoeventAddress::Mmio(io_event.address), }; match io_event.length { 0 => vm.register_ioevent(&evt, addr, Datamatch::AnyLength)?, 1 => vm.register_ioevent(&evt, addr, Datamatch::U8(Some(io_event.datamatch as u8)))?, 2 => { vm.register_ioevent(&evt, addr, Datamatch::U16(Some(io_event.datamatch as u16)))? } 4 => { vm.register_ioevent(&evt, addr, Datamatch::U32(Some(io_event.datamatch as u32)))? } 8 => { vm.register_ioevent(&evt, addr, Datamatch::U64(Some(io_event.datamatch as u64)))? } _ => return Err(SysError::new(EINVAL)), }; let fd = evt.as_raw_descriptor(); entry.insert(PluginObject::IoEvent { evt, addr, length: io_event.length, datamatch: io_event.datamatch, }); Ok(fd) } fn handle_memory( entry: VacantEntry, vm: &mut Vm, memfd: File, offset: u64, start: u64, length: u64, read_only: bool, dirty_log: bool, ) -> SysResult<()> { let shm = SharedMemory::from_file(memfd)?; // Checking the seals ensures the plugin process won't shrink the mmapped file, causing us // to SIGBUS in the future. let seals = shm.get_seals()?; if !seals.shrink_seal() { return Err(SysError::new(EPERM)); } // Check to make sure we don't mmap areas beyond the end of the memfd. match length.checked_add(offset) { Some(end) if end > shm.size() => return Err(SysError::new(EINVAL)), None => return Err(SysError::new(EOVERFLOW)), _ => {} } let mem = MemoryMappingBuilder::new(length as usize) .from_shared_memory(&shm) .offset(offset) .build() .map_err(mmap_to_sys_err)?; let slot = vm.add_memory_region(GuestAddress(start), Box::new(mem), read_only, dirty_log)?; entry.insert(PluginObject::Memory { slot, length: length as usize, }); Ok(()) } fn handle_reserve_range(&mut self, reserve_range: &MainRequest_ReserveRange) -> SysResult<()> { match self.shared_vcpu_state.write() { Ok(mut lock) => { let space = match reserve_range.space { AddressSpace::IOPORT => IoSpace::Ioport, AddressSpace::MMIO => IoSpace::Mmio, }; match reserve_range.length { 0 => lock.unreserve_range(space, reserve_range.start), _ => lock.reserve_range( space, reserve_range.start, reserve_range.length, reserve_range.async_write, ), } } Err(_) => Err(SysError::new(EDEADLK)), } } fn handle_set_irq_routing( vm: &mut Vm, irq_routing: &MainRequest_SetIrqRouting, ) -> SysResult<()> { let mut routes = Vec::with_capacity(irq_routing.routes.len()); for route in &irq_routing.routes { routes.push(IrqRoute { gsi: route.irq_id, source: if route.has_irqchip() { let irqchip = route.get_irqchip(); IrqSource::Irqchip { chip: irqchip.irqchip, pin: irqchip.pin, } } else if route.has_msi() { let msi = route.get_msi(); IrqSource::Msi { address: msi.address, data: msi.data, } } else { // Because route is a oneof field in the proto definition, this should // only happen if a new variant gets added without updating this chained // if block. return Err(SysError::new(EINVAL)); }, }); } vm.set_gsi_routing(&routes[..]) } fn handle_set_call_hint(&mut self, hints: &MainRequest_SetCallHint) -> SysResult<()> { let mut regs: Vec = vec![]; for hint in &hints.hints { regs.push(CallHintDetails { match_rax: hint.match_rax, match_rbx: hint.match_rbx, match_rcx: hint.match_rcx, match_rdx: hint.match_rdx, rax: hint.rax, rbx: hint.rbx, rcx: hint.rcx, rdx: hint.rdx, send_sregs: hint.send_sregs, send_debugregs: hint.send_debugregs, }); } match self.shared_vcpu_state.write() { Ok(mut lock) => { let space = match hints.space { AddressSpace::IOPORT => IoSpace::Ioport, AddressSpace::MMIO => IoSpace::Mmio, }; lock.set_hint(space, hints.address, hints.on_write, regs); Ok(()) } Err(_) => Err(SysError::new(EDEADLK)), } } fn handle_pause_vcpus(&self, vcpu_handles: &[JoinHandle<()>], cpu_mask: u64, user_data: u64) { for (cpu_id, (handle, per_cpu_state)) in vcpu_handles.iter().zip(&self.per_vcpu_states).enumerate() { if cpu_mask & (1 << cpu_id) != 0 { per_cpu_state.lock().request_pause(user_data); if let Err(e) = handle.kill(SIGRTMIN() + 0) { error!("failed to interrupt vcpu {}: {}", cpu_id, e); } } } } fn handle_get_net_config( tap: &net_util::Tap, config: &mut MainResponse_GetNetConfig, ) -> SysResult<()> { // Log any NetError so that the cause can be found later, but extract and return the // underlying errno for the client as well. fn map_net_error(s: &str, e: NetError) -> SysError { error!("failed to get {}: {}", s, e); e.sys_error() } let ip_addr = tap.ip_addr().map_err(|e| map_net_error("IP address", e))?; config.set_host_ipv4_address(u32::from(ip_addr)); let netmask = tap.netmask().map_err(|e| map_net_error("netmask", e))?; config.set_netmask(u32::from(netmask)); let result_mac_addr = config.mut_host_mac_address(); let mac_addr_octets = tap .mac_address() .map_err(|e| map_net_error("mac address", e))? .octets(); result_mac_addr.resize(mac_addr_octets.len(), 0); result_mac_addr.clone_from_slice(&mac_addr_octets); Ok(()) } /// Handles a request on a readable socket identified by its index in the slice returned by /// `sockets`. /// /// The `vm` is used to service request that affect the VM. The `vcpu_handles` slice is used to /// interrupt a VCPU thread currently running in the VM if the socket request it. pub fn handle_socket( &mut self, index: usize, kvm: &Kvm, vm: &mut Vm, vcpu_handles: &[JoinHandle<()>], taps: &[Tap], ) -> Result<()> { let (msg_size, request_file) = self.request_sockets[index] .recv_with_fd(&mut self.request_buffer) .map_err(Error::PluginSocketRecv)?; if msg_size == 0 { return Err(Error::PluginSocketHup); } let request = protobuf::parse_from_bytes::(&self.request_buffer[..msg_size]) .map_err(Error::DecodeRequest)?; /// Use this to make it easier to stuff various kinds of File-like objects into the /// `boxed_fds` list. fn box_owned_fd(f: F) -> Box { Box::new(f) } // This vec is used to extend ownership of certain FDs until the end of this function. let mut boxed_fds = Vec::new(); let mut response_fds = Vec::new(); let mut response = MainResponse::new(); let res = if request.has_create() { response.mut_create(); let create = request.get_create(); match self.objects.entry(create.id) { Entry::Vacant(entry) => { if create.has_io_event() { match Self::handle_io_event(entry, vm, create.get_io_event()) { Ok(fd) => { response_fds.push(fd); Ok(()) } Err(e) => Err(e), } } else if create.has_memory() { let memory = create.get_memory(); match request_file { Some(memfd) => Self::handle_memory( entry, vm, memfd, memory.offset, memory.start, memory.length, memory.read_only, memory.dirty_log, ), None => Err(SysError::new(EBADF)), } } else if create.has_irq_event() { let irq_event = create.get_irq_event(); match (Event::new(), Event::new()) { (Ok(evt), Ok(resample_evt)) => match vm.register_irqfd_resample( &evt, &resample_evt, irq_event.irq_id, ) { Ok(()) => { response_fds.push(evt.as_raw_descriptor()); response_fds.push(resample_evt.as_raw_descriptor()); boxed_fds.push(box_owned_fd(resample_evt)); entry.insert(PluginObject::IrqEvent { irq_id: irq_event.irq_id, evt, }); Ok(()) } Err(e) => Err(e), }, (Err(e), _) | (_, Err(e)) => Err(e), } } else { Err(SysError::new(ENOTTY)) } } Entry::Occupied(_) => Err(SysError::new(EEXIST)), } } else if request.has_destroy() { response.mut_destroy(); match self.objects.entry(request.get_destroy().id) { Entry::Occupied(entry) => entry.remove().destroy(vm), Entry::Vacant(_) => Err(SysError::new(ENOENT)), } } else if request.has_new_connection() { response.mut_new_connection(); match new_seqpacket_pair() { Ok((request_socket, child_socket)) => { self.request_sockets.push(request_socket); response_fds.push(child_socket.as_raw_descriptor()); boxed_fds.push(box_owned_fd(child_socket)); Ok(()) } Err(e) => Err(e), } } else if request.has_get_shutdown_eventfd() { response.mut_get_shutdown_eventfd(); response_fds.push(self.kill_evt.as_raw_descriptor()); Ok(()) } else if request.has_check_extension() { // Safe because the Cap enum is not read by the check_extension method. In that method, // cap is cast back to an integer and fed to an ioctl. If the extension name is actually // invalid, the kernel will safely reject the extension under the assumption that the // capability is legitimately unsupported. let cap = unsafe { transmute(request.get_check_extension().extension) }; response.mut_check_extension().has_extension = vm.check_extension(cap); Ok(()) } else if request.has_reserve_range() { response.mut_reserve_range(); self.handle_reserve_range(request.get_reserve_range()) } else if request.has_set_irq() { response.mut_set_irq(); let irq = request.get_set_irq(); vm.set_irq_line(irq.irq_id, irq.active) } else if request.has_set_irq_routing() { response.mut_set_irq_routing(); Self::handle_set_irq_routing(vm, request.get_set_irq_routing()) } else if request.has_get_state() { let response_state = response.mut_get_state(); match get_vm_state(vm, request.get_get_state().set) { Ok(state) => { response_state.state = state; Ok(()) } Err(e) => Err(e), } } else if request.has_set_state() { response.mut_set_state(); let set_state = request.get_set_state(); set_vm_state(vm, set_state.set, set_state.get_state()) } else if request.has_set_identity_map_addr() { response.mut_set_identity_map_addr(); let addr = request.get_set_identity_map_addr().address; vm.set_identity_map_addr(GuestAddress(addr as u64)) } else if request.has_pause_vcpus() { response.mut_pause_vcpus(); let pause_vcpus = request.get_pause_vcpus(); self.handle_pause_vcpus(vcpu_handles, pause_vcpus.cpu_mask, pause_vcpus.user); Ok(()) } else if request.has_get_vcpus() { response.mut_get_vcpus(); for pipe in self.vcpu_pipes.iter() { response_fds.push(pipe.plugin_write.as_raw_descriptor()); response_fds.push(pipe.plugin_read.as_raw_descriptor()); } Ok(()) } else if request.has_start() { response.mut_start(); if self.started { Err(SysError::new(EINVAL)) } else { self.started = true; Ok(()) } } else if request.has_get_net_config() { match taps.first() { Some(tap) => { match Self::handle_get_net_config(tap, response.mut_get_net_config()) { Ok(_) => { response_fds.push(tap.as_raw_descriptor()); Ok(()) } Err(e) => Err(e), } } None => Err(SysError::new(ENODATA)), } } else if request.has_set_call_hint() { response.mut_set_call_hint(); self.handle_set_call_hint(request.get_set_call_hint()) } else if request.has_dirty_log() { let dirty_log_response = response.mut_dirty_log(); match self.objects.get(&request.get_dirty_log().id) { Some(&PluginObject::Memory { slot, length }) => { let dirty_log = dirty_log_response.mut_bitmap(); dirty_log.resize(dirty_log_bitmap_size(length), 0); vm.get_dirty_log(slot, &mut dirty_log[..]) } _ => Err(SysError::new(ENOENT)), } } else if request.has_get_supported_cpuid() { let cpuid_response = &mut response.mut_get_supported_cpuid().entries; match kvm.get_supported_cpuid() { Ok(mut cpuid) => { for entry in cpuid.mut_entries_slice() { cpuid_response.push(cpuid_kvm_to_proto(entry)); } Ok(()) } Err(e) => Err(e), } } else if request.has_get_emulated_cpuid() { let cpuid_response = &mut response.mut_get_emulated_cpuid().entries; match kvm.get_emulated_cpuid() { Ok(mut cpuid) => { for entry in cpuid.mut_entries_slice() { cpuid_response.push(cpuid_kvm_to_proto(entry)); } Ok(()) } Err(e) => Err(e), } } else if request.has_get_msr_index_list() { let msr_list_response = &mut response.mut_get_msr_index_list().indices; match kvm.get_msr_index_list() { Ok(indices) => { for entry in indices { msr_list_response.push(entry); } Ok(()) } Err(e) => Err(e), } } else { Err(SysError::new(ENOTTY)) }; if let Err(e) = res { response.errno = e.errno(); } self.response_buffer.clear(); response .write_to_vec(&mut self.response_buffer) .map_err(Error::EncodeResponse)?; assert_ne!(self.response_buffer.len(), 0); self.request_sockets[index] .send_with_fds(&[IoSlice::new(&self.response_buffer[..])], &response_fds) .map_err(Error::PluginSocketSend)?; Ok(()) } } impl Drop for Process { fn drop(&mut self) { // Ignore the result because there is nothing we can do about it. if let Err(e) = self.signal_kill() { error!("failed to signal kill event for plugin: {}", e); } } }