cloud-hypervisor/vm-virtio/src/vhost_user/blk.rs

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// Copyright 2019 Intel Corporation. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
use libc;
use libc::EFD_NONBLOCK;
use std::cmp;
use std::io::Write;
use std::ptr::null;
use std::sync::{Arc, RwLock};
use std::thread;
use std::vec::Vec;
use crate::VirtioInterrupt;
use vm_memory::GuestMemoryMmap;
use vmm_sys_util::eventfd::EventFd;
use super::super::{ActivateError, ActivateResult, Queue, VirtioDevice, VirtioDeviceType};
use super::handler::*;
use super::vu_common_ctrl::*;
use super::{Error, Result};
use std::mem;
use vhost_rs::vhost_user::message::VhostUserConfigFlags;
use vhost_rs::vhost_user::message::{VhostUserProtocolFeatures, VhostUserVirtioFeatures};
use vhost_rs::vhost_user::{Master, VhostUserMaster, VhostUserMasterReqHandler};
use vhost_rs::VhostBackend;
use virtio_bindings::bindings::virtio_blk::*;
macro_rules! offset_of {
($ty:ty, $field:ident) => {
unsafe { &(*(null() as *const $ty)).$field as *const _ as usize }
};
}
struct SlaveReqHandler {}
impl VhostUserMasterReqHandler for SlaveReqHandler {}
pub struct Blk {
vhost_user_blk: Master,
kill_evt: EventFd,
avail_features: u64,
acked_features: u64,
config_space: Vec<u8>,
queue_sizes: Vec<u16>,
}
impl<'a> Blk {
/// Create a new vhost-user-blk device
pub fn new(wce: bool, vu_cfg: VhostUserConfig<'a>) -> Result<Blk> {
let mut vhost_user_blk = Master::connect(vu_cfg.sock, vu_cfg.num_queues as u64)
.map_err(Error::VhostUserCreateMaster)?;
let kill_evt = EventFd::new(EFD_NONBLOCK).map_err(Error::CreateKillEventFd)?;
// Filling device and vring features VMM supports.
let mut avail_features = 1 << VIRTIO_BLK_F_SEG_MAX
| 1 << VIRTIO_BLK_F_RO
| 1 << VIRTIO_BLK_F_BLK_SIZE
| 1 << VIRTIO_BLK_F_FLUSH
| 1 << VIRTIO_BLK_F_TOPOLOGY
| 1 << VIRTIO_F_VERSION_1
| VhostUserVirtioFeatures::PROTOCOL_FEATURES.bits();
// Set vhost-user owner.
vhost_user_blk
.set_owner()
.map_err(Error::VhostUserSetOwner)?;
// Get features from backend, do negotiation to get a feature collection which
// both VMM and backend support.
let backend_features = vhost_user_blk
.get_features()
.map_err(Error::VhostUserGetFeatures)?;
avail_features &= backend_features;
// Set features back is required by the vhost crate mechanism, since the
// later vhost call will check if features is filled in master before execution.
vhost_user_blk
.set_features(avail_features)
.map_err(Error::VhostUserSetFeatures)?;
// Identify if protocol features are supported by the slave.
let mut acked_features = 0;
if avail_features & VhostUserVirtioFeatures::PROTOCOL_FEATURES.bits() != 0 {
acked_features |= VhostUserVirtioFeatures::PROTOCOL_FEATURES.bits();
let mut protocol_features = vhost_user_blk
.get_protocol_features()
.map_err(Error::VhostUserGetProtocolFeatures)?;
protocol_features |= VhostUserProtocolFeatures::MQ;
protocol_features &= !VhostUserProtocolFeatures::INFLIGHT_SHMFD;
vhost_user_blk
.set_protocol_features(protocol_features)
.map_err(Error::VhostUserSetProtocolFeatures)?;
}
let config_len = mem::size_of::<virtio_blk_config>();
let mut config_space: Vec<u8> = vec![0u8; config_len as usize];
let queue_num_offset = offset_of!(virtio_blk_config, num_queues);
// only setnum_queues value.
config_space[queue_num_offset] = vu_cfg.num_queues as u8;
Ok(Blk {
vhost_user_blk,
kill_evt,
avail_features,
acked_features,
config_space,
queue_sizes: vec![vu_cfg.queue_size; vu_cfg.num_queues],
})
}
}
impl Drop for Blk {
fn drop(&mut self) {
if let Err(_e) = self.kill_evt.write(1) {
error!("failed to kill vhost-user-blk with error {}", _e);
}
}
}
impl VirtioDevice for Blk {
fn device_type(&self) -> u32 {
VirtioDeviceType::TYPE_BLOCK as u32
}
fn queue_max_sizes(&self) -> &[u16] {
&self.queue_sizes
}
fn features(&self, page: u32) -> u32 {
match page {
0 => self.avail_features as u32,
1 => (self.avail_features >> 32) as u32,
_ => {
warn!("Received request for unknown features page: {}", 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: {}", 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: {:x}", v);
// 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: Arc<RwLock<GuestMemoryMmap>>,
interrupt_cb: Arc<VirtioInterrupt>,
queues: Vec<Queue>,
queue_evts: Vec<EventFd>,
) -> ActivateResult {
let handler_kill_evt = self
.kill_evt
.try_clone()
.map_err(|_| ActivateError::CloneKillEventFd)?;
let vu_interrupt_list = setup_vhost_user(
&mut self.vhost_user_blk,
&mem.read().unwrap(),
queues,
queue_evts,
self.acked_features,
)
.map_err(ActivateError::VhostUserBlkSetup)?;
let mut handler = VhostUserEpollHandler::<SlaveReqHandler>::new(VhostUserEpollConfig {
interrupt_cb,
kill_evt: handler_kill_evt,
vu_interrupt_list,
slave_req_handler: None,
});
let handler_result = thread::Builder::new()
.name("vhost_user_blk".to_string())
.spawn(move || {
if let Err(e) = handler.run() {
error!("net worker thread exited with error {:?}!", e);
}
});
if let Err(e) = handler_result {
error!("vhost-user blk thread create failed with error {:?}", e);
}
Ok(())
}
}