diff --git a/vm-virtio/src/block.rs b/vm-virtio/src/block.rs
new file mode 100644
index 000000000..8f8a826af
--- /dev/null
+++ b/vm-virtio/src/block.rs
@@ -0,0 +1,589 @@
+// Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+//
+// Portions 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 THIRD-PARTY file.
+
+use epoll;
+use libc::EFD_NONBLOCK;
+use std::cmp;
+use std::fs::File;
+use std::io::{self, Read, Seek, SeekFrom, Write};
+use std::os::linux::fs::MetadataExt;
+use std::os::unix::io::AsRawFd;
+use std::result;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
+use std::thread;
+
+use super::Error as DeviceError;
+use super::{
+    ActivateError, ActivateResult, DescriptorChain, DeviceEventT, Queue, VirtioDevice,
+    VirtioDeviceType, INTERRUPT_STATUS_USED_RING,
+};
+use virtio_bindings::virtio_blk::*;
+use vm_memory::{Bytes, GuestAddress, GuestMemory, GuestMemoryError, GuestMemoryMmap};
+use vmm_sys_util::EventFd;
+
+const CONFIG_SPACE_SIZE: usize = 8;
+const SECTOR_SHIFT: u8 = 9;
+pub const SECTOR_SIZE: u64 = (0x01 as u64) << SECTOR_SHIFT;
+const QUEUE_SIZE: u16 = 256;
+const NUM_QUEUES: usize = 1;
+const QUEUE_SIZES: &[u16] = &[QUEUE_SIZE];
+
+// New descriptors are pending on the virtio queue.
+const QUEUE_AVAIL_EVENT: DeviceEventT = 0;
+// The device has been dropped.
+pub const KILL_EVENT: DeviceEventT = 1;
+// Number of DeviceEventT events supported by this implementation.
+pub const BLOCK_EVENTS_COUNT: usize = 2;
+
+#[derive(Debug)]
+enum Error {
+    /// Guest gave us bad memory addresses.
+    GuestMemory(GuestMemoryError),
+    /// Guest gave us offsets that would have overflowed a usize.
+    CheckedOffset(GuestAddress, usize),
+    /// Guest gave us a write only descriptor that protocol says to read from.
+    UnexpectedWriteOnlyDescriptor,
+    /// Guest gave us a read only descriptor that protocol says to write to.
+    UnexpectedReadOnlyDescriptor,
+    /// Guest gave us too few descriptors in a descriptor chain.
+    DescriptorChainTooShort,
+    /// Guest gave us a descriptor that was too short to use.
+    DescriptorLengthTooSmall,
+    /// Getting a block's metadata fails for any reason.
+    GetFileMetadata,
+    /// The requested operation would cause a seek beyond disk end.
+    InvalidOffset,
+}
+
+#[derive(Debug)]
+enum ExecuteError {
+    BadRequest(Error),
+    Flush(io::Error),
+    Read(GuestMemoryError),
+    Seek(io::Error),
+    Write(GuestMemoryError),
+    Unsupported(u32),
+}
+
+impl ExecuteError {
+    fn status(&self) -> u32 {
+        match *self {
+            ExecuteError::BadRequest(_) => VIRTIO_BLK_S_IOERR,
+            ExecuteError::Flush(_) => VIRTIO_BLK_S_IOERR,
+            ExecuteError::Read(_) => VIRTIO_BLK_S_IOERR,
+            ExecuteError::Seek(_) => VIRTIO_BLK_S_IOERR,
+            ExecuteError::Write(_) => VIRTIO_BLK_S_IOERR,
+            ExecuteError::Unsupported(_) => VIRTIO_BLK_S_UNSUPP,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq)]
+enum RequestType {
+    In,
+    Out,
+    Flush,
+    GetDeviceID,
+    Unsupported(u32),
+}
+
+fn request_type(
+    mem: &GuestMemoryMmap,
+    desc_addr: GuestAddress,
+) -> result::Result<RequestType, Error> {
+    let type_ = mem.read_obj(desc_addr).map_err(Error::GuestMemory)?;
+    match type_ {
+        VIRTIO_BLK_T_IN => Ok(RequestType::In),
+        VIRTIO_BLK_T_OUT => Ok(RequestType::Out),
+        VIRTIO_BLK_T_FLUSH => Ok(RequestType::Flush),
+        VIRTIO_BLK_T_GET_ID => Ok(RequestType::GetDeviceID),
+        t => Ok(RequestType::Unsupported(t)),
+    }
+}
+
+fn sector(mem: &GuestMemoryMmap, desc_addr: GuestAddress) -> result::Result<u64, Error> {
+    const SECTOR_OFFSET: usize = 8;
+    let addr = match mem.checked_offset(desc_addr, SECTOR_OFFSET) {
+        Some(v) => v,
+        None => return Err(Error::CheckedOffset(desc_addr, SECTOR_OFFSET)),
+    };
+
+    mem.read_obj(addr).map_err(Error::GuestMemory)
+}
+
+fn build_device_id(disk_image: &File) -> result::Result<String, Error> {
+    let blk_metadata = match disk_image.metadata() {
+        Err(_) => return Err(Error::GetFileMetadata),
+        Ok(m) => m,
+    };
+    // This is how kvmtool does it.
+    let device_id = format!(
+        "{}{}{}",
+        blk_metadata.st_dev(),
+        blk_metadata.st_rdev(),
+        blk_metadata.st_ino()
+    )
+    .to_owned();
+    Ok(device_id)
+}
+
+fn build_disk_image_id(disk_image: &File) -> Vec<u8> {
+    let mut default_disk_image_id = vec![0; VIRTIO_BLK_ID_BYTES as usize];
+    match build_device_id(disk_image) {
+        Err(_) => {
+            warn!("Could not generate device id. We'll use a default.");
+        }
+        Ok(m) => {
+            // The kernel only knows to read a maximum of VIRTIO_BLK_ID_BYTES.
+            // This will also zero out any leftover bytes.
+            let disk_id = m.as_bytes();
+            let bytes_to_copy = cmp::min(disk_id.len(), VIRTIO_BLK_ID_BYTES as usize);
+            default_disk_image_id[..bytes_to_copy].clone_from_slice(&disk_id[..bytes_to_copy])
+        }
+    }
+    default_disk_image_id
+}
+
+struct Request {
+    request_type: RequestType,
+    sector: u64,
+    data_addr: GuestAddress,
+    data_len: u32,
+    status_addr: GuestAddress,
+}
+
+impl Request {
+    fn parse(
+        avail_desc: &DescriptorChain,
+        mem: &GuestMemoryMmap,
+    ) -> result::Result<Request, Error> {
+        // The head contains the request type which MUST be readable.
+        if avail_desc.is_write_only() {
+            return Err(Error::UnexpectedWriteOnlyDescriptor);
+        }
+
+        let mut req = Request {
+            request_type: request_type(&mem, avail_desc.addr)?,
+            sector: sector(&mem, avail_desc.addr)?,
+            data_addr: GuestAddress(0),
+            data_len: 0,
+            status_addr: GuestAddress(0),
+        };
+
+        let data_desc;
+        let status_desc;
+        let desc = avail_desc
+            .next_descriptor()
+            .ok_or(Error::DescriptorChainTooShort)?;
+
+        if !desc.has_next() {
+            status_desc = desc;
+            // Only flush requests are allowed to skip the data descriptor.
+            if req.request_type != RequestType::Flush {
+                return Err(Error::DescriptorChainTooShort);
+            }
+        } else {
+            data_desc = desc;
+            status_desc = data_desc
+                .next_descriptor()
+                .ok_or(Error::DescriptorChainTooShort)?;
+
+            if data_desc.is_write_only() && req.request_type == RequestType::Out {
+                return Err(Error::UnexpectedWriteOnlyDescriptor);
+            }
+            if !data_desc.is_write_only() && req.request_type == RequestType::In {
+                return Err(Error::UnexpectedReadOnlyDescriptor);
+            }
+            if !data_desc.is_write_only() && req.request_type == RequestType::GetDeviceID {
+                return Err(Error::UnexpectedReadOnlyDescriptor);
+            }
+
+            req.data_addr = data_desc.addr;
+            req.data_len = data_desc.len;
+        }
+
+        // The status MUST always be writable.
+        if !status_desc.is_write_only() {
+            return Err(Error::UnexpectedReadOnlyDescriptor);
+        }
+
+        if status_desc.len < 1 {
+            return Err(Error::DescriptorLengthTooSmall);
+        }
+
+        req.status_addr = status_desc.addr;
+
+        Ok(req)
+    }
+
+    #[allow(clippy::ptr_arg)]
+    fn execute<T: Seek + Read + Write>(
+        &self,
+        disk: &mut T,
+        disk_nsectors: u64,
+        mem: &GuestMemoryMmap,
+        disk_id: &Vec<u8>,
+    ) -> result::Result<u32, ExecuteError> {
+        let mut top: u64 = u64::from(self.data_len) / SECTOR_SIZE;
+        if u64::from(self.data_len) % SECTOR_SIZE != 0 {
+            top += 1;
+        }
+        top = top
+            .checked_add(self.sector)
+            .ok_or(ExecuteError::BadRequest(Error::InvalidOffset))?;
+        if top > disk_nsectors {
+            return Err(ExecuteError::BadRequest(Error::InvalidOffset));
+        }
+
+        disk.seek(SeekFrom::Start(self.sector << SECTOR_SHIFT))
+            .map_err(ExecuteError::Seek)?;
+
+        match self.request_type {
+            RequestType::In => {
+                mem.read_exact_from(self.data_addr, disk, self.data_len as usize)
+                    .map_err(ExecuteError::Read)?;
+                return Ok(self.data_len);
+            }
+            RequestType::Out => {
+                mem.write_all_to(self.data_addr, disk, self.data_len as usize)
+                    .map_err(ExecuteError::Write)?;
+            }
+            RequestType::Flush => match disk.flush() {
+                Ok(_) => {
+                    return Ok(0);
+                }
+                Err(e) => return Err(ExecuteError::Flush(e)),
+            },
+            RequestType::GetDeviceID => {
+                if (self.data_len as usize) < disk_id.len() {
+                    return Err(ExecuteError::BadRequest(Error::InvalidOffset));
+                }
+                mem.write_slice(&disk_id.as_slice(), self.data_addr)
+                    .map_err(ExecuteError::Write)?;
+            }
+            RequestType::Unsupported(t) => return Err(ExecuteError::Unsupported(t)),
+        };
+        Ok(0)
+    }
+}
+
+struct BlockEpollHandler {
+    queues: Vec<Queue>,
+    mem: GuestMemoryMmap,
+    disk_image: File,
+    disk_nsectors: u64,
+    interrupt_status: Arc<AtomicUsize>,
+    interrupt_evt: EventFd,
+    disk_image_id: Vec<u8>,
+}
+
+impl BlockEpollHandler {
+    fn process_queue(&mut self, queue_index: usize) -> bool {
+        let queue = &mut self.queues[queue_index];
+
+        let mut used_desc_heads = [(0, 0); QUEUE_SIZE as usize];
+        let mut used_count = 0;
+        for avail_desc in queue.iter(&self.mem) {
+            let len;
+            match Request::parse(&avail_desc, &self.mem) {
+                Ok(request) => {
+                    let status = match request.execute(
+                        &mut self.disk_image,
+                        self.disk_nsectors,
+                        &self.mem,
+                        &self.disk_image_id,
+                    ) {
+                        Ok(l) => {
+                            len = l;
+                            VIRTIO_BLK_S_OK
+                        }
+                        Err(e) => {
+                            error!("Failed to execute request: {:?}", e);
+                            len = 1; // We need at least 1 byte for the status.
+                            e.status()
+                        }
+                    };
+                    // We use unwrap because the request parsing process already checked that the
+                    // status_addr was valid.
+                    self.mem.write_obj(status, request.status_addr).unwrap();
+                }
+                Err(e) => {
+                    error!("Failed to parse available descriptor chain: {:?}", e);
+                    len = 0;
+                }
+            }
+            used_desc_heads[used_count] = (avail_desc.index, len);
+            used_count += 1;
+        }
+
+        for &(desc_index, len) in &used_desc_heads[..used_count] {
+            queue.add_used(&self.mem, desc_index, len);
+        }
+        used_count > 0
+    }
+
+    fn signal_used_queue(&self) -> result::Result<(), DeviceError> {
+        self.interrupt_status
+            .fetch_or(INTERRUPT_STATUS_USED_RING as usize, Ordering::SeqCst);
+        self.interrupt_evt.write(1).map_err(|e| {
+            error!("Failed to signal used queue: {:?}", e);
+            DeviceError::FailedSignalingUsedQueue(e)
+        })
+    }
+
+    #[allow(dead_code)]
+    fn update_disk_image(&mut self, disk_image: File) -> result::Result<(), DeviceError> {
+        self.disk_image = disk_image;
+        self.disk_nsectors = self
+            .disk_image
+            .seek(SeekFrom::End(0))
+            .map_err(DeviceError::IoError)?
+            / SECTOR_SIZE;
+        self.disk_image_id = build_disk_image_id(&self.disk_image);
+        Ok(())
+    }
+
+    fn run(&mut self, queue_evt: EventFd, kill_evt: EventFd) -> result::Result<(), DeviceError> {
+        // Create the epoll file descriptor
+        let epoll_fd = epoll::create(true).map_err(DeviceError::EpollCreateFd)?;
+
+        // Add events
+        epoll::ctl(
+            epoll_fd,
+            epoll::ControlOptions::EPOLL_CTL_ADD,
+            queue_evt.as_raw_fd(),
+            epoll::Event::new(epoll::Events::EPOLLIN, u64::from(QUEUE_AVAIL_EVENT)),
+        )
+        .map_err(DeviceError::EpollCtl)?;
+        epoll::ctl(
+            epoll_fd,
+            epoll::ControlOptions::EPOLL_CTL_ADD,
+            kill_evt.as_raw_fd(),
+            epoll::Event::new(epoll::Events::EPOLLIN, u64::from(KILL_EVENT)),
+        )
+        .map_err(DeviceError::EpollCtl)?;
+
+        const EPOLL_EVENTS_LEN: usize = 100;
+        let mut events = vec![epoll::Event::new(epoll::Events::empty(), 0); EPOLL_EVENTS_LEN];
+
+        'epoll: loop {
+            let num_events =
+                epoll::wait(epoll_fd, -1, &mut events[..]).map_err(DeviceError::EpollWait)?;
+
+            for event in events.iter().take(num_events) {
+                let ev_type = event.data as u16;
+
+                match ev_type {
+                    QUEUE_AVAIL_EVENT => {
+                        if let Err(e) = queue_evt.read() {
+                            error!("Failed to get queue event: {:?}", e);
+                            break 'epoll;
+                        } else if self.process_queue(0) {
+                            if let Err(e) = self.signal_used_queue() {
+                                error!("Failed to signal used queue: {:?}", e);
+                                break 'epoll;
+                            }
+                        }
+                    }
+                    KILL_EVENT => {
+                        debug!("KILL_EVENT received, stopping epoll loop");
+                        break 'epoll;
+                    }
+                    _ => {
+                        error!("Unknown event for virtio-block");
+                    }
+                }
+            }
+        }
+
+        Ok(())
+    }
+}
+
+/// Virtio device for exposing block level read/write operations on a host file.
+pub struct Block {
+    kill_evt: Option<EventFd>,
+    disk_image: Option<File>,
+    disk_nsectors: u64,
+    avail_features: u64,
+    acked_features: u64,
+    config_space: Vec<u8>,
+}
+
+pub fn build_config_space(disk_size: u64) -> Vec<u8> {
+    // We only support disk size, which uses the first two words of the configuration space.
+    // If the image is not a multiple of the sector size, the tail bits are not exposed.
+    // The config space is little endian.
+    let mut config = Vec::with_capacity(CONFIG_SPACE_SIZE);
+    let num_sectors = disk_size >> SECTOR_SHIFT;
+    for i in 0..8 {
+        config.push((num_sectors >> (8 * i)) as u8);
+    }
+    config
+}
+
+impl Block {
+    /// Create a new virtio block device that operates on the given file.
+    ///
+    /// The given file must be seekable and sizable.
+    pub fn new(mut disk_image: File, is_disk_read_only: bool) -> io::Result<Block> {
+        let disk_size = disk_image.seek(SeekFrom::End(0))? as u64;
+        if disk_size % SECTOR_SIZE != 0 {
+            warn!(
+                "Disk size {} is not a multiple of sector size {}; \
+                 the remainder will not be visible to the guest.",
+                disk_size, SECTOR_SIZE
+            );
+        }
+
+        let mut avail_features = (1u64 << VIRTIO_F_VERSION_1) | (1u64 << VIRTIO_BLK_F_FLUSH);
+
+        if is_disk_read_only {
+            avail_features |= 1u64 << VIRTIO_BLK_F_RO;
+        };
+
+        Ok(Block {
+            kill_evt: None,
+            disk_image: Some(disk_image),
+            disk_nsectors: disk_size / SECTOR_SIZE,
+            avail_features,
+            acked_features: 0u64,
+            config_space: build_config_space(disk_size),
+        })
+    }
+}
+
+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);
+        }
+    }
+}
+
+impl VirtioDevice for Block {
+    fn device_type(&self) -> u32 {
+        VirtioDeviceType::TYPE_BLOCK as u32
+    }
+
+    fn queue_max_sizes(&self) -> &[u16] {
+        QUEUE_SIZES
+    }
+
+    fn features(&self, page: u32) -> u32 {
+        match page {
+            // Get the lower 32-bits of the features bitfield.
+            0 => self.avail_features as u32,
+            // Get the upper 32-bits of the features bitfield.
+            1 => (self.avail_features >> 32) as u32,
+            _ => {
+                warn!("Received request for unknown features page.");
+                0u32
+            }
+        }
+    }
+
+    fn ack_features(&mut self, page: u32, value: u32) {
+        let mut v = match page {
+            0 => u64::from(value),
+            1 => u64::from(value) << 32,
+            _ => {
+                warn!("Cannot acknowledge unknown features page.");
+                0u64
+            }
+        };
+
+        // Check if the guest is ACK'ing a feature that we didn't claim to have.
+        let unrequested_features = v & !self.avail_features;
+        if unrequested_features != 0 {
+            warn!("Received acknowledge request for unknown feature.");
+
+            // Don't count these features as acked.
+            v &= !unrequested_features;
+        }
+        self.acked_features |= v;
+    }
+
+    fn read_config(&self, offset: u64, mut data: &mut [u8]) {
+        let config_len = self.config_space.len() as u64;
+        if offset >= config_len {
+            error!("Failed to read config space");
+            return;
+        }
+        if let Some(end) = offset.checked_add(data.len() as u64) {
+            // This write can't fail, offset and end are checked against config_len.
+            data.write_all(&self.config_space[offset as usize..cmp::min(end, config_len) as usize])
+                .unwrap();
+        }
+    }
+
+    fn write_config(&mut self, offset: u64, data: &[u8]) {
+        let data_len = data.len() as u64;
+        let config_len = self.config_space.len() as u64;
+        if offset + data_len > config_len {
+            error!("Failed to write config space");
+            return;
+        }
+        let (_, right) = self.config_space.split_at_mut(offset as usize);
+        right.copy_from_slice(&data[..]);
+    }
+
+    fn activate(
+        &mut self,
+        mem: GuestMemoryMmap,
+        interrupt_evt: EventFd,
+        status: Arc<AtomicUsize>,
+        queues: Vec<Queue>,
+        mut queue_evts: Vec<EventFd>,
+    ) -> ActivateResult {
+        if queues.len() != NUM_QUEUES || queue_evts.len() != NUM_QUEUES {
+            error!(
+                "Cannot perform activate. Expected {} queue(s), got {}",
+                NUM_QUEUES,
+                queues.len()
+            );
+            return Err(ActivateError::BadActivate);
+        }
+
+        let (self_kill_evt, kill_evt) =
+            match EventFd::new(EFD_NONBLOCK).and_then(|e| Ok((e.try_clone()?, e))) {
+                Ok(v) => v,
+                Err(e) => {
+                    error!("failed creating kill EventFd pair: {}", e);
+                    return Err(ActivateError::BadActivate);
+                }
+            };
+        self.kill_evt = Some(self_kill_evt);
+
+        if let Some(disk_image) = self.disk_image.take() {
+            let disk_image_id = build_disk_image_id(&disk_image);
+            let mut handler = BlockEpollHandler {
+                queues,
+                mem,
+                disk_image,
+                disk_nsectors: self.disk_nsectors,
+                interrupt_status: status,
+                interrupt_evt,
+                disk_image_id,
+            };
+
+            let worker_result = thread::Builder::new()
+                .name("virtio_blk".to_string())
+                .spawn(move || handler.run(queue_evts.remove(0), kill_evt));
+
+            if let Err(e) = worker_result {
+                error!("failed to spawn virtio_blk worker: {}", e);
+                return Err(ActivateError::BadActivate);
+            }
+
+            return Ok(());
+        }
+        Err(ActivateError::BadActivate)
+    }
+}