| // 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::cmp::{max, min}; |
| use std::fmt::{self, Display}; |
| use std::io::{self, Write}; |
| use std::mem::size_of; |
| use std::result; |
| use std::sync::Arc; |
| use std::thread; |
| use std::time::Duration; |
| use std::u32; |
| |
| use base::Error as SysError; |
| use base::Result as SysResult; |
| use base::{ |
| error, info, iov_max, warn, AsRawDescriptor, Event, PollToken, RawDescriptor, Timer, Tube, |
| WaitContext, |
| }; |
| use data_model::{DataInit, Le16, Le32, Le64}; |
| use disk::DiskFile; |
| |
| use sync::Mutex; |
| use vm_control::{DiskControlCommand, DiskControlResult}; |
| use vm_memory::GuestMemory; |
| |
| use super::{ |
| copy_config, DescriptorChain, DescriptorError, Interrupt, Queue, Reader, VirtioDevice, Writer, |
| TYPE_BLOCK, |
| }; |
| |
| const QUEUE_SIZE: u16 = 256; |
| const QUEUE_SIZES: &[u16] = &[QUEUE_SIZE]; |
| const SECTOR_SHIFT: u8 = 9; |
| const SECTOR_SIZE: u64 = 0x01 << SECTOR_SHIFT; |
| const MAX_DISCARD_SECTORS: u32 = u32::MAX; |
| const MAX_WRITE_ZEROES_SECTORS: u32 = u32::MAX; |
| // Arbitrary limits for number of discard/write zeroes segments. |
| const MAX_DISCARD_SEG: u32 = 32; |
| const MAX_WRITE_ZEROES_SEG: u32 = 32; |
| // Hard-coded to 64 KiB (in 512-byte sectors) for now, |
| // but this should probably be based on cluster size for qcow. |
| const DISCARD_SECTOR_ALIGNMENT: u32 = 128; |
| |
| const ID_LEN: usize = 20; |
| |
| /// Virtio block device identifier. |
| /// This is an ASCII string terminated by a \0, unless all 20 bytes are used, |
| /// in which case the \0 terminator is omitted. |
| pub type BlockId = [u8; ID_LEN]; |
| |
| const VIRTIO_BLK_T_IN: u32 = 0; |
| const VIRTIO_BLK_T_OUT: u32 = 1; |
| const VIRTIO_BLK_T_FLUSH: u32 = 4; |
| const VIRTIO_BLK_T_GET_ID: u32 = 8; |
| const VIRTIO_BLK_T_DISCARD: u32 = 11; |
| const VIRTIO_BLK_T_WRITE_ZEROES: u32 = 13; |
| |
| const VIRTIO_BLK_S_OK: u8 = 0; |
| const VIRTIO_BLK_S_IOERR: u8 = 1; |
| const VIRTIO_BLK_S_UNSUPP: u8 = 2; |
| |
| const VIRTIO_BLK_F_SEG_MAX: u32 = 2; |
| const VIRTIO_BLK_F_RO: u32 = 5; |
| const VIRTIO_BLK_F_BLK_SIZE: u32 = 6; |
| const VIRTIO_BLK_F_FLUSH: u32 = 9; |
| const VIRTIO_BLK_F_DISCARD: u32 = 13; |
| const VIRTIO_BLK_F_WRITE_ZEROES: u32 = 14; |
| |
| #[derive(Copy, Clone, Debug, Default)] |
| #[repr(C)] |
| struct virtio_blk_geometry { |
| cylinders: Le16, |
| heads: u8, |
| sectors: u8, |
| } |
| |
| // Safe because it only has data and has no implicit padding. |
| unsafe impl DataInit for virtio_blk_geometry {} |
| |
| #[derive(Copy, Clone, Debug, Default)] |
| #[repr(C)] |
| struct virtio_blk_topology { |
| physical_block_exp: u8, |
| alignment_offset: u8, |
| min_io_size: Le16, |
| opt_io_size: Le32, |
| } |
| |
| // Safe because it only has data and has no implicit padding. |
| unsafe impl DataInit for virtio_blk_topology {} |
| |
| #[derive(Copy, Clone, Debug, Default)] |
| #[repr(C, packed)] |
| struct virtio_blk_config { |
| capacity: Le64, |
| size_max: Le32, |
| seg_max: Le32, |
| geometry: virtio_blk_geometry, |
| blk_size: Le32, |
| topology: virtio_blk_topology, |
| writeback: u8, |
| unused0: [u8; 3], |
| max_discard_sectors: Le32, |
| max_discard_seg: Le32, |
| discard_sector_alignment: Le32, |
| max_write_zeroes_sectors: Le32, |
| max_write_zeroes_seg: Le32, |
| write_zeroes_may_unmap: u8, |
| unused1: [u8; 3], |
| } |
| |
| // Safe because it only has data and has no implicit padding. |
| unsafe impl DataInit for virtio_blk_req_header {} |
| |
| #[derive(Copy, Clone, Debug, Default)] |
| #[repr(C)] |
| struct virtio_blk_req_header { |
| req_type: Le32, |
| reserved: Le32, |
| sector: Le64, |
| } |
| |
| // Safe because it only has data and has no implicit padding. |
| unsafe impl DataInit for virtio_blk_config {} |
| |
| #[derive(Copy, Clone, Debug, Default)] |
| #[repr(C)] |
| struct virtio_blk_discard_write_zeroes { |
| sector: Le64, |
| num_sectors: Le32, |
| flags: Le32, |
| } |
| |
| const VIRTIO_BLK_DISCARD_WRITE_ZEROES_FLAG_UNMAP: u32 = 1 << 0; |
| |
| // Safe because it only has data and has no implicit padding. |
| unsafe impl DataInit for virtio_blk_discard_write_zeroes {} |
| |
| #[derive(Debug)] |
| enum ExecuteError { |
| CopyId(io::Error), |
| Descriptor(DescriptorError), |
| Read(io::Error), |
| WriteStatus(io::Error), |
| /// Error arming the flush timer. |
| Flush(io::Error), |
| ReadIo { |
| length: usize, |
| sector: u64, |
| desc_error: io::Error, |
| }, |
| Timer(SysError), |
| WriteIo { |
| length: usize, |
| sector: u64, |
| desc_error: io::Error, |
| }, |
| DiscardWriteZeroes { |
| ioerr: Option<io::Error>, |
| sector: u64, |
| num_sectors: u32, |
| flags: u32, |
| }, |
| ReadOnly { |
| request_type: u32, |
| }, |
| OutOfRange, |
| MissingStatus, |
| Unsupported(u32), |
| } |
| |
| impl Display for ExecuteError { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| use self::ExecuteError::*; |
| |
| match self { |
| CopyId(e) => write!(f, "failed to copy ID string: {}", e), |
| Descriptor(e) => write!(f, "virtio descriptor error: {}", e), |
| Read(e) => write!(f, "failed to read message: {}", e), |
| WriteStatus(e) => write!(f, "failed to write request status: {}", e), |
| Flush(e) => write!(f, "failed to flush: {}", e), |
| ReadIo { |
| length, |
| sector, |
| desc_error, |
| } => write!( |
| f, |
| "io error reading {} bytes from sector {}: {}", |
| length, sector, desc_error, |
| ), |
| Timer(e) => write!(f, "{}", e), |
| WriteIo { |
| length, |
| sector, |
| desc_error, |
| } => write!( |
| f, |
| "io error writing {} bytes to sector {}: {}", |
| length, sector, desc_error, |
| ), |
| DiscardWriteZeroes { |
| ioerr: Some(ioerr), |
| sector, |
| num_sectors, |
| flags, |
| } => write!( |
| f, |
| "failed to perform discard or write zeroes; sector={} num_sectors={} flags={}; {}", |
| sector, num_sectors, flags, ioerr, |
| ), |
| DiscardWriteZeroes { |
| ioerr: None, |
| sector, |
| num_sectors, |
| flags, |
| } => write!( |
| f, |
| "failed to perform discard or write zeroes; sector={} num_sectors={} flags={}", |
| sector, num_sectors, flags, |
| ), |
| ReadOnly { request_type } => write!(f, "read only; request_type={}", request_type), |
| OutOfRange => write!(f, "out of range"), |
| MissingStatus => write!(f, "not enough space in descriptor chain to write status"), |
| Unsupported(n) => write!(f, "unsupported ({})", n), |
| } |
| } |
| } |
| |
| impl ExecuteError { |
| fn status(&self) -> u8 { |
| match self { |
| ExecuteError::CopyId(_) => VIRTIO_BLK_S_IOERR, |
| ExecuteError::Descriptor(_) => VIRTIO_BLK_S_IOERR, |
| ExecuteError::Read(_) => VIRTIO_BLK_S_IOERR, |
| ExecuteError::WriteStatus(_) => VIRTIO_BLK_S_IOERR, |
| ExecuteError::Flush(_) => VIRTIO_BLK_S_IOERR, |
| ExecuteError::ReadIo { .. } => VIRTIO_BLK_S_IOERR, |
| ExecuteError::Timer(_) => VIRTIO_BLK_S_IOERR, |
| ExecuteError::WriteIo { .. } => VIRTIO_BLK_S_IOERR, |
| ExecuteError::DiscardWriteZeroes { .. } => VIRTIO_BLK_S_IOERR, |
| ExecuteError::ReadOnly { .. } => VIRTIO_BLK_S_IOERR, |
| ExecuteError::OutOfRange { .. } => VIRTIO_BLK_S_IOERR, |
| ExecuteError::MissingStatus => VIRTIO_BLK_S_IOERR, |
| ExecuteError::Unsupported(_) => VIRTIO_BLK_S_UNSUPP, |
| } |
| } |
| } |
| |
| struct Worker { |
| interrupt: Interrupt, |
| queues: Vec<Queue>, |
| mem: GuestMemory, |
| disk_image: Box<dyn DiskFile>, |
| disk_size: Arc<Mutex<u64>>, |
| read_only: bool, |
| sparse: bool, |
| id: Option<BlockId>, |
| control_tube: Option<Tube>, |
| } |
| |
| impl Worker { |
| fn process_one_request( |
| avail_desc: DescriptorChain, |
| read_only: bool, |
| sparse: bool, |
| disk: &mut dyn DiskFile, |
| disk_size: u64, |
| id: Option<BlockId>, |
| flush_timer: &mut Timer, |
| flush_timer_armed: &mut bool, |
| mem: &GuestMemory, |
| ) -> result::Result<usize, ExecuteError> { |
| let mut reader = |
| Reader::new(mem.clone(), avail_desc.clone()).map_err(ExecuteError::Descriptor)?; |
| let mut writer = Writer::new(mem.clone(), avail_desc).map_err(ExecuteError::Descriptor)?; |
| |
| // The last byte of the buffer is virtio_blk_req::status. |
| // Split it into a separate Writer so that status_writer is the final byte and |
| // the original writer is left with just the actual block I/O data. |
| let available_bytes = writer.available_bytes(); |
| let status_offset = available_bytes |
| .checked_sub(1) |
| .ok_or(ExecuteError::MissingStatus)?; |
| let mut status_writer = writer.split_at(status_offset); |
| |
| let status = match Block::execute_request( |
| &mut reader, |
| &mut writer, |
| read_only, |
| sparse, |
| disk, |
| disk_size, |
| id, |
| flush_timer, |
| flush_timer_armed, |
| ) { |
| Ok(()) => VIRTIO_BLK_S_OK, |
| Err(e) => { |
| error!("failed executing disk request: {}", e); |
| e.status() |
| } |
| }; |
| |
| status_writer |
| .write_all(&[status]) |
| .map_err(ExecuteError::WriteStatus)?; |
| Ok(available_bytes) |
| } |
| |
| fn process_queue( |
| &mut self, |
| queue_index: usize, |
| flush_timer: &mut Timer, |
| flush_timer_armed: &mut bool, |
| ) { |
| let queue = &mut self.queues[queue_index]; |
| |
| let disk_size = self.disk_size.lock(); |
| |
| while let Some(avail_desc) = queue.pop(&self.mem) { |
| queue.set_notify(&self.mem, false); |
| let desc_index = avail_desc.index; |
| |
| let len = match Worker::process_one_request( |
| avail_desc, |
| self.read_only, |
| self.sparse, |
| &mut *self.disk_image, |
| *disk_size, |
| self.id, |
| flush_timer, |
| flush_timer_armed, |
| &self.mem, |
| ) { |
| Ok(len) => len, |
| Err(e) => { |
| error!("block: failed to handle request: {}", e); |
| 0 |
| } |
| }; |
| |
| queue.add_used(&self.mem, desc_index, len as u32); |
| queue.trigger_interrupt(&self.mem, &self.interrupt); |
| queue.set_notify(&self.mem, true); |
| } |
| } |
| |
| fn resize(&mut self, new_size: u64) -> DiskControlResult { |
| if self.read_only { |
| error!("Attempted to resize read-only block device"); |
| return DiskControlResult::Err(SysError::new(libc::EROFS)); |
| } |
| |
| info!("Resizing block device to {} bytes", new_size); |
| |
| if let Err(e) = self.disk_image.set_len(new_size) { |
| error!("Resizing disk failed! {}", e); |
| return DiskControlResult::Err(SysError::new(libc::EIO)); |
| } |
| |
| // Allocate new space if the disk image is not sparse. |
| if let Err(e) = self.disk_image.allocate(0, new_size) { |
| error!("Allocating disk space after resize failed! {}", e); |
| return DiskControlResult::Err(SysError::new(libc::EIO)); |
| } |
| |
| self.sparse = false; |
| |
| if let Ok(new_disk_size) = self.disk_image.get_len() { |
| let mut disk_size = self.disk_size.lock(); |
| *disk_size = new_disk_size; |
| } |
| DiskControlResult::Ok |
| } |
| |
| fn run(&mut self, queue_evt: Event, kill_evt: Event) { |
| #[derive(PollToken)] |
| enum Token { |
| FlushTimer, |
| QueueAvailable, |
| ControlRequest, |
| InterruptResample, |
| Kill, |
| } |
| |
| let mut flush_timer = match Timer::new() { |
| Ok(t) => t, |
| Err(e) => { |
| error!("Failed to create the flush timer: {}", e); |
| return; |
| } |
| }; |
| let mut flush_timer_armed = false; |
| |
| let wait_ctx: WaitContext<Token> = match WaitContext::build_with(&[ |
| (&flush_timer, Token::FlushTimer), |
| (&queue_evt, Token::QueueAvailable), |
| (self.interrupt.get_resample_evt(), Token::InterruptResample), |
| (&kill_evt, Token::Kill), |
| ]) |
| .and_then(|pc| { |
| if let Some(control_tube) = self.control_tube.as_ref() { |
| pc.add(control_tube, Token::ControlRequest)? |
| } |
| Ok(pc) |
| }) { |
| Ok(pc) => pc, |
| Err(e) => { |
| error!("failed creating WaitContext: {}", e); |
| return; |
| } |
| }; |
| |
| 'wait: loop { |
| let events = match wait_ctx.wait() { |
| Ok(v) => v, |
| Err(e) => { |
| error!("failed polling for events: {}", e); |
| break; |
| } |
| }; |
| |
| let mut needs_config_interrupt = false; |
| for event in events.iter().filter(|e| e.is_readable) { |
| match event.token { |
| Token::FlushTimer => { |
| if let Err(e) = self.disk_image.fsync() { |
| error!("Failed to flush the disk: {}", e); |
| break 'wait; |
| } |
| if let Err(e) = flush_timer.wait() { |
| error!("Failed to clear flush timer: {}", e); |
| break 'wait; |
| } |
| } |
| Token::QueueAvailable => { |
| if let Err(e) = queue_evt.read() { |
| error!("failed reading queue Event: {}", e); |
| break 'wait; |
| } |
| self.process_queue(0, &mut flush_timer, &mut flush_timer_armed); |
| } |
| Token::ControlRequest => { |
| let control_tube = match self.control_tube.as_ref() { |
| Some(cs) => cs, |
| None => { |
| error!("received control socket request with no control socket"); |
| break 'wait; |
| } |
| }; |
| let req = match control_tube.recv() { |
| Ok(req) => req, |
| Err(e) => { |
| error!("control socket failed recv: {}", e); |
| break 'wait; |
| } |
| }; |
| |
| let resp = match req { |
| DiskControlCommand::Resize { new_size } => { |
| let resize_resp = self.resize(new_size); |
| if let DiskControlResult::Ok = resize_resp { |
| needs_config_interrupt = true; |
| } |
| resize_resp |
| } |
| }; |
| |
| // We already know there is Some control_tube used to recv a request. |
| if let Err(e) = self.control_tube.as_ref().unwrap().send(&resp) { |
| error!("control socket failed send: {}", e); |
| break 'wait; |
| } |
| } |
| Token::InterruptResample => { |
| self.interrupt.interrupt_resample(); |
| } |
| Token::Kill => break 'wait, |
| } |
| } |
| if needs_config_interrupt { |
| self.interrupt.signal_config_changed(); |
| } |
| } |
| } |
| } |
| |
| /// Virtio device for exposing block level read/write operations on a host file. |
| pub struct Block { |
| kill_evt: Option<Event>, |
| worker_thread: Option<thread::JoinHandle<Worker>>, |
| disk_image: Option<Box<dyn DiskFile>>, |
| disk_size: Arc<Mutex<u64>>, |
| avail_features: u64, |
| read_only: bool, |
| sparse: bool, |
| seg_max: u32, |
| block_size: u32, |
| id: Option<BlockId>, |
| control_tube: Option<Tube>, |
| } |
| |
| fn build_config_space(disk_size: u64, seg_max: u32, block_size: u32) -> virtio_blk_config { |
| virtio_blk_config { |
| // If the image is not a multiple of the sector size, the tail bits are not exposed. |
| capacity: Le64::from(disk_size >> SECTOR_SHIFT), |
| seg_max: Le32::from(seg_max), |
| blk_size: Le32::from(block_size), |
| max_discard_sectors: Le32::from(MAX_DISCARD_SECTORS), |
| discard_sector_alignment: Le32::from(DISCARD_SECTOR_ALIGNMENT), |
| max_write_zeroes_sectors: Le32::from(MAX_WRITE_ZEROES_SECTORS), |
| write_zeroes_may_unmap: 1, |
| max_discard_seg: Le32::from(MAX_DISCARD_SEG), |
| max_write_zeroes_seg: Le32::from(MAX_WRITE_ZEROES_SEG), |
| ..Default::default() |
| } |
| } |
| |
| impl Block { |
| /// Create a new virtio block device that operates on the given DiskFile. |
| pub fn new( |
| base_features: u64, |
| disk_image: Box<dyn DiskFile>, |
| read_only: bool, |
| sparse: bool, |
| block_size: u32, |
| id: Option<BlockId>, |
| control_tube: Option<Tube>, |
| ) -> SysResult<Block> { |
| if block_size % SECTOR_SIZE as u32 != 0 { |
| error!( |
| "Block size {} is not a multiple of {}.", |
| block_size, SECTOR_SIZE, |
| ); |
| return Err(SysError::new(libc::EINVAL)); |
| } |
| let disk_size = disk_image.get_len()?; |
| if disk_size % block_size as u64 != 0 { |
| warn!( |
| "Disk size {} is not a multiple of block size {}; \ |
| the remainder will not be visible to the guest.", |
| disk_size, block_size, |
| ); |
| } |
| |
| let mut avail_features: u64 = base_features; |
| avail_features |= 1 << VIRTIO_BLK_F_FLUSH; |
| if read_only { |
| avail_features |= 1 << VIRTIO_BLK_F_RO; |
| } else { |
| if sparse { |
| avail_features |= 1 << VIRTIO_BLK_F_DISCARD; |
| } |
| avail_features |= 1 << VIRTIO_BLK_F_WRITE_ZEROES; |
| } |
| avail_features |= 1 << VIRTIO_BLK_F_SEG_MAX; |
| avail_features |= 1 << VIRTIO_BLK_F_BLK_SIZE; |
| |
| let seg_max = min(max(iov_max(), 1), u32::max_value() as usize) as u32; |
| |
| // Since we do not currently support indirect descriptors, the maximum |
| // number of segments must be smaller than the queue size. |
| // In addition, the request header and status each consume a descriptor. |
| let seg_max = min(seg_max, u32::from(QUEUE_SIZE) - 2); |
| |
| Ok(Block { |
| kill_evt: None, |
| worker_thread: None, |
| disk_image: Some(disk_image), |
| disk_size: Arc::new(Mutex::new(disk_size)), |
| avail_features, |
| read_only, |
| sparse, |
| seg_max, |
| block_size, |
| id, |
| control_tube, |
| }) |
| } |
| |
| // Execute a single block device request. |
| // `writer` includes the data region only; the status byte is not included. |
| // It is up to the caller to convert the result of this function into a status byte |
| // and write it to the expected location in guest memory. |
| fn execute_request( |
| reader: &mut Reader, |
| writer: &mut Writer, |
| read_only: bool, |
| sparse: bool, |
| disk: &mut dyn DiskFile, |
| disk_size: u64, |
| id: Option<BlockId>, |
| flush_timer: &mut Timer, |
| flush_timer_armed: &mut bool, |
| ) -> result::Result<(), ExecuteError> { |
| let req_header: virtio_blk_req_header = reader.read_obj().map_err(ExecuteError::Read)?; |
| |
| let req_type = req_header.req_type.to_native(); |
| let sector = req_header.sector.to_native(); |
| // Delay after a write when the file is auto-flushed. |
| let flush_delay = Duration::from_secs(60); |
| |
| if read_only && req_type != VIRTIO_BLK_T_IN && req_type != VIRTIO_BLK_T_GET_ID { |
| return Err(ExecuteError::ReadOnly { |
| request_type: req_type, |
| }); |
| } |
| |
| /// Check that a request accesses only data within the disk's current size. |
| /// All parameters are in units of bytes. |
| fn check_range( |
| io_start: u64, |
| io_length: u64, |
| disk_size: u64, |
| ) -> result::Result<(), ExecuteError> { |
| let io_end = io_start |
| .checked_add(io_length) |
| .ok_or(ExecuteError::OutOfRange)?; |
| if io_end > disk_size { |
| Err(ExecuteError::OutOfRange) |
| } else { |
| Ok(()) |
| } |
| } |
| |
| match req_type { |
| VIRTIO_BLK_T_IN => { |
| let data_len = writer.available_bytes(); |
| let offset = sector |
| .checked_shl(u32::from(SECTOR_SHIFT)) |
| .ok_or(ExecuteError::OutOfRange)?; |
| check_range(offset, data_len as u64, disk_size)?; |
| writer |
| .write_all_from_at(disk, data_len, offset) |
| .map_err(|desc_error| ExecuteError::ReadIo { |
| length: data_len, |
| sector, |
| desc_error, |
| })?; |
| } |
| VIRTIO_BLK_T_OUT => { |
| let data_len = reader.available_bytes(); |
| let offset = sector |
| .checked_shl(u32::from(SECTOR_SHIFT)) |
| .ok_or(ExecuteError::OutOfRange)?; |
| check_range(offset, data_len as u64, disk_size)?; |
| reader |
| .read_exact_to_at(disk, data_len, offset) |
| .map_err(|desc_error| ExecuteError::WriteIo { |
| length: data_len, |
| sector, |
| desc_error, |
| })?; |
| if !*flush_timer_armed { |
| flush_timer |
| .reset(flush_delay, None) |
| .map_err(ExecuteError::Timer)?; |
| *flush_timer_armed = true; |
| } |
| } |
| VIRTIO_BLK_T_DISCARD | VIRTIO_BLK_T_WRITE_ZEROES => { |
| if req_type == VIRTIO_BLK_T_DISCARD && !sparse { |
| // Discard is a hint; if this is a non-sparse disk, just ignore it. |
| return Ok(()); |
| } |
| |
| while reader.available_bytes() >= size_of::<virtio_blk_discard_write_zeroes>() { |
| let seg: virtio_blk_discard_write_zeroes = |
| reader.read_obj().map_err(ExecuteError::Read)?; |
| |
| let sector = seg.sector.to_native(); |
| let num_sectors = seg.num_sectors.to_native(); |
| let flags = seg.flags.to_native(); |
| |
| let valid_flags = if req_type == VIRTIO_BLK_T_WRITE_ZEROES { |
| VIRTIO_BLK_DISCARD_WRITE_ZEROES_FLAG_UNMAP |
| } else { |
| 0 |
| }; |
| |
| if (flags & !valid_flags) != 0 { |
| return Err(ExecuteError::DiscardWriteZeroes { |
| ioerr: None, |
| sector, |
| num_sectors, |
| flags, |
| }); |
| } |
| |
| let offset = sector |
| .checked_shl(u32::from(SECTOR_SHIFT)) |
| .ok_or(ExecuteError::OutOfRange)?; |
| let length = u64::from(num_sectors) |
| .checked_shl(u32::from(SECTOR_SHIFT)) |
| .ok_or(ExecuteError::OutOfRange)?; |
| check_range(offset, length, disk_size)?; |
| |
| if req_type == VIRTIO_BLK_T_DISCARD { |
| // Since Discard is just a hint and some filesystems may not implement |
| // FALLOC_FL_PUNCH_HOLE, ignore punch_hole errors. |
| let _ = disk.punch_hole(offset, length); |
| } else { |
| disk.write_zeroes_all_at(offset, length as usize) |
| .map_err(|e| ExecuteError::DiscardWriteZeroes { |
| ioerr: Some(e), |
| sector, |
| num_sectors, |
| flags, |
| })?; |
| } |
| } |
| } |
| VIRTIO_BLK_T_FLUSH => { |
| disk.fsync().map_err(ExecuteError::Flush)?; |
| flush_timer.clear().map_err(ExecuteError::Timer)?; |
| *flush_timer_armed = false; |
| } |
| VIRTIO_BLK_T_GET_ID => { |
| if let Some(id) = id { |
| writer.write_all(&id).map_err(ExecuteError::CopyId)?; |
| } else { |
| return Err(ExecuteError::Unsupported(req_type)); |
| } |
| } |
| t => return Err(ExecuteError::Unsupported(t)), |
| }; |
| Ok(()) |
| } |
| } |
| |
| impl Drop for Block { |
| fn drop(&mut self) { |
| if let Some(kill_evt) = self.kill_evt.take() { |
| // Ignore the result because there is nothing we can do about it. |
| let _ = kill_evt.write(1); |
| } |
| |
| if let Some(worker_thread) = self.worker_thread.take() { |
| let _ = worker_thread.join(); |
| } |
| } |
| } |
| |
| impl VirtioDevice for Block { |
| fn keep_rds(&self) -> Vec<RawDescriptor> { |
| let mut keep_rds = Vec::new(); |
| |
| if let Some(disk_image) = &self.disk_image { |
| keep_rds.extend(disk_image.as_raw_descriptors()); |
| } |
| |
| if let Some(control_tube) = &self.control_tube { |
| keep_rds.push(control_tube.as_raw_descriptor()); |
| } |
| |
| keep_rds |
| } |
| |
| fn features(&self) -> u64 { |
| self.avail_features |
| } |
| |
| fn device_type(&self) -> u32 { |
| TYPE_BLOCK |
| } |
| |
| fn queue_max_sizes(&self) -> &[u16] { |
| QUEUE_SIZES |
| } |
| |
| fn read_config(&self, offset: u64, data: &mut [u8]) { |
| let config_space = { |
| let disk_size = self.disk_size.lock(); |
| build_config_space(*disk_size, self.seg_max, self.block_size) |
| }; |
| copy_config(data, 0, config_space.as_slice(), offset); |
| } |
| |
| fn activate( |
| &mut self, |
| mem: GuestMemory, |
| interrupt: Interrupt, |
| queues: Vec<Queue>, |
| mut queue_evts: Vec<Event>, |
| ) { |
| if queues.len() != 1 || queue_evts.len() != 1 { |
| return; |
| } |
| |
| let (self_kill_evt, kill_evt) = match Event::new().and_then(|e| Ok((e.try_clone()?, e))) { |
| Ok(v) => v, |
| Err(e) => { |
| error!("failed creating kill Event pair: {}", e); |
| return; |
| } |
| }; |
| self.kill_evt = Some(self_kill_evt); |
| |
| let read_only = self.read_only; |
| let sparse = self.sparse; |
| let disk_size = self.disk_size.clone(); |
| let id = self.id.take(); |
| if let Some(disk_image) = self.disk_image.take() { |
| let control_tube = self.control_tube.take(); |
| let worker_result = |
| thread::Builder::new() |
| .name("virtio_blk".to_string()) |
| .spawn(move || { |
| let mut worker = Worker { |
| interrupt, |
| queues, |
| mem, |
| disk_image, |
| disk_size, |
| read_only, |
| sparse, |
| id, |
| control_tube, |
| }; |
| worker.run(queue_evts.remove(0), kill_evt); |
| worker |
| }); |
| |
| match worker_result { |
| Err(e) => { |
| error!("failed to spawn virtio_blk worker: {}", e); |
| return; |
| } |
| Ok(join_handle) => { |
| self.worker_thread = Some(join_handle); |
| } |
| } |
| } |
| } |
| |
| fn reset(&mut self) -> bool { |
| if let Some(kill_evt) = self.kill_evt.take() { |
| if kill_evt.write(1).is_err() { |
| error!("{}: failed to notify the kill event", self.debug_label()); |
| return false; |
| } |
| } |
| |
| if let Some(worker_thread) = self.worker_thread.take() { |
| match worker_thread.join() { |
| Err(_) => { |
| error!("{}: failed to get back resources", self.debug_label()); |
| return false; |
| } |
| Ok(worker) => { |
| self.disk_image = Some(worker.disk_image); |
| self.control_tube = worker.control_tube; |
| return true; |
| } |
| } |
| } |
| false |
| } |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use std::mem::size_of_val; |
| use tempfile::tempfile; |
| use vm_memory::GuestAddress; |
| |
| use crate::virtio::base_features; |
| use crate::virtio::descriptor_utils::{create_descriptor_chain, DescriptorType}; |
| use crate::ProtectionType; |
| |
| use super::*; |
| |
| #[test] |
| fn read_size() { |
| let f = tempfile().unwrap(); |
| f.set_len(0x1000).unwrap(); |
| |
| let features = base_features(ProtectionType::Unprotected); |
| let b = Block::new(features, Box::new(f), true, false, 512, None, None).unwrap(); |
| let mut num_sectors = [0u8; 4]; |
| b.read_config(0, &mut num_sectors); |
| // size is 0x1000, so num_sectors is 8 (4096/512). |
| assert_eq!([0x08, 0x00, 0x00, 0x00], num_sectors); |
| let mut msw_sectors = [0u8; 4]; |
| b.read_config(4, &mut msw_sectors); |
| // size is 0x1000, so msw_sectors is 0. |
| assert_eq!([0x00, 0x00, 0x00, 0x00], msw_sectors); |
| } |
| |
| #[test] |
| fn read_block_size() { |
| let f = tempfile().unwrap(); |
| f.set_len(0x1000).unwrap(); |
| |
| let features = base_features(ProtectionType::Unprotected); |
| let b = Block::new(features, Box::new(f), true, false, 4096, None, None).unwrap(); |
| let mut blk_size = [0u8; 4]; |
| b.read_config(20, &mut blk_size); |
| // blk_size should be 4096 (0x1000). |
| assert_eq!([0x00, 0x10, 0x00, 0x00], blk_size); |
| } |
| |
| #[test] |
| fn read_features() { |
| // read-write block device |
| { |
| let f = tempfile().unwrap(); |
| let features = base_features(ProtectionType::Unprotected); |
| let b = Block::new(features, Box::new(f), false, true, 512, None, None).unwrap(); |
| // writable device should set VIRTIO_BLK_F_FLUSH + VIRTIO_BLK_F_DISCARD |
| // + VIRTIO_BLK_F_WRITE_ZEROES + VIRTIO_F_VERSION_1 + VIRTIO_BLK_F_BLK_SIZE |
| // + VIRTIO_BLK_F_SEG_MAX |
| assert_eq!(0x100006244, b.features()); |
| } |
| |
| // read-write block device, non-sparse |
| { |
| let f = tempfile().unwrap(); |
| let features = base_features(ProtectionType::Unprotected); |
| let b = Block::new(features, Box::new(f), false, false, 512, None, None).unwrap(); |
| // writable device should set VIRTIO_BLK_F_FLUSH |
| // + VIRTIO_BLK_F_WRITE_ZEROES + VIRTIO_F_VERSION_1 + VIRTIO_BLK_F_BLK_SIZE |
| // + VIRTIO_BLK_F_SEG_MAX |
| assert_eq!(0x100004244, b.features()); |
| } |
| |
| // read-only block device |
| { |
| let f = tempfile().unwrap(); |
| let features = base_features(ProtectionType::Unprotected); |
| let b = Block::new(features, Box::new(f), true, true, 512, None, None).unwrap(); |
| // read-only device should set VIRTIO_BLK_F_FLUSH and VIRTIO_BLK_F_RO |
| // + VIRTIO_F_VERSION_1 + VIRTIO_BLK_F_BLK_SIZE + VIRTIO_BLK_F_SEG_MAX |
| assert_eq!(0x100000264, b.features()); |
| } |
| } |
| |
| #[test] |
| fn read_last_sector() { |
| let mut f = tempfile().unwrap(); |
| let disk_size = 0x1000; |
| f.set_len(disk_size).unwrap(); |
| |
| let mem = GuestMemory::new(&[(GuestAddress(0u64), 4 * 1024 * 1024)]) |
| .expect("Creating guest memory failed."); |
| |
| let req_hdr = virtio_blk_req_header { |
| req_type: Le32::from(VIRTIO_BLK_T_IN), |
| reserved: Le32::from(0), |
| sector: Le64::from(7), // Disk is 8 sectors long, so this is the last valid sector. |
| }; |
| mem.write_obj_at_addr(req_hdr, GuestAddress(0x1000)) |
| .expect("writing req failed"); |
| |
| let avail_desc = create_descriptor_chain( |
| &mem, |
| GuestAddress(0x100), // Place descriptor chain at 0x100. |
| GuestAddress(0x1000), // Describe buffer at 0x1000. |
| vec![ |
| // Request header |
| (DescriptorType::Readable, size_of_val(&req_hdr) as u32), |
| // I/O buffer (1 sector of data) |
| (DescriptorType::Writable, 512), |
| // Request status |
| (DescriptorType::Writable, 1), |
| ], |
| 0, |
| ) |
| .expect("create_descriptor_chain failed"); |
| |
| let mut flush_timer = Timer::new().expect("failed to create flush_timer"); |
| let mut flush_timer_armed = false; |
| |
| Worker::process_one_request( |
| avail_desc, |
| false, |
| true, |
| &mut f, |
| disk_size, |
| None, |
| &mut flush_timer, |
| &mut flush_timer_armed, |
| &mem, |
| ) |
| .expect("execute failed"); |
| |
| let status_offset = GuestAddress((0x1000 + size_of_val(&req_hdr) + 512) as u64); |
| let status = mem.read_obj_from_addr::<u8>(status_offset).unwrap(); |
| assert_eq!(status, VIRTIO_BLK_S_OK); |
| } |
| |
| #[test] |
| fn read_beyond_last_sector() { |
| let mut f = tempfile().unwrap(); |
| let disk_size = 0x1000; |
| f.set_len(disk_size).unwrap(); |
| |
| let mem = GuestMemory::new(&[(GuestAddress(0u64), 4 * 1024 * 1024)]) |
| .expect("Creating guest memory failed."); |
| |
| let req_hdr = virtio_blk_req_header { |
| req_type: Le32::from(VIRTIO_BLK_T_IN), |
| reserved: Le32::from(0), |
| sector: Le64::from(7), // Disk is 8 sectors long, so this is the last valid sector. |
| }; |
| mem.write_obj_at_addr(req_hdr, GuestAddress(0x1000)) |
| .expect("writing req failed"); |
| |
| let avail_desc = create_descriptor_chain( |
| &mem, |
| GuestAddress(0x100), // Place descriptor chain at 0x100. |
| GuestAddress(0x1000), // Describe buffer at 0x1000. |
| vec![ |
| // Request header |
| (DescriptorType::Readable, size_of_val(&req_hdr) as u32), |
| // I/O buffer (2 sectors of data - overlap the end of the disk). |
| (DescriptorType::Writable, 512 * 2), |
| // Request status |
| (DescriptorType::Writable, 1), |
| ], |
| 0, |
| ) |
| .expect("create_descriptor_chain failed"); |
| |
| let mut flush_timer = Timer::new().expect("failed to create flush_timer"); |
| let mut flush_timer_armed = false; |
| |
| Worker::process_one_request( |
| avail_desc, |
| false, |
| true, |
| &mut f, |
| disk_size, |
| None, |
| &mut flush_timer, |
| &mut flush_timer_armed, |
| &mem, |
| ) |
| .expect("execute failed"); |
| |
| let status_offset = GuestAddress((0x1000 + size_of_val(&req_hdr) + 512 * 2) as u64); |
| let status = mem.read_obj_from_addr::<u8>(status_offset).unwrap(); |
| assert_eq!(status, VIRTIO_BLK_S_IOERR); |
| } |
| |
| #[test] |
| fn get_id() { |
| let mut f = tempfile().unwrap(); |
| let disk_size = 0x1000; |
| f.set_len(disk_size).unwrap(); |
| |
| let mem = GuestMemory::new(&[(GuestAddress(0u64), 4 * 1024 * 1024)]) |
| .expect("Creating guest memory failed."); |
| |
| let req_hdr = virtio_blk_req_header { |
| req_type: Le32::from(VIRTIO_BLK_T_GET_ID), |
| reserved: Le32::from(0), |
| sector: Le64::from(0), |
| }; |
| mem.write_obj_at_addr(req_hdr, GuestAddress(0x1000)) |
| .expect("writing req failed"); |
| |
| let avail_desc = create_descriptor_chain( |
| &mem, |
| GuestAddress(0x100), // Place descriptor chain at 0x100. |
| GuestAddress(0x1000), // Describe buffer at 0x1000. |
| vec![ |
| // Request header |
| (DescriptorType::Readable, size_of_val(&req_hdr) as u32), |
| // I/O buffer (20 bytes for serial) |
| (DescriptorType::Writable, 20), |
| // Request status |
| (DescriptorType::Writable, 1), |
| ], |
| 0, |
| ) |
| .expect("create_descriptor_chain failed"); |
| |
| let mut flush_timer = Timer::new().expect("failed to create flush_timer"); |
| let mut flush_timer_armed = false; |
| |
| let id = b"a20-byteserialnumber"; |
| |
| Worker::process_one_request( |
| avail_desc, |
| false, |
| true, |
| &mut f, |
| disk_size, |
| Some(*id), |
| &mut flush_timer, |
| &mut flush_timer_armed, |
| &mem, |
| ) |
| .expect("execute failed"); |
| |
| let status_offset = GuestAddress((0x1000 + size_of_val(&req_hdr) + 20) as u64); |
| let status = mem.read_obj_from_addr::<u8>(status_offset).unwrap(); |
| assert_eq!(status, VIRTIO_BLK_S_OK); |
| |
| let id_offset = GuestAddress(0x1000 + size_of_val(&req_hdr) as u64); |
| let returned_id = mem.read_obj_from_addr::<[u8; 20]>(id_offset).unwrap(); |
| assert_eq!(returned_id, *id); |
| } |
| } |