cloud-hypervisor/fuzz/fuzz_targets/watchdog.rs
Sebastien Boeuf 1f0e5eb66a vmm: virtio-devices: Restore every VirtioDevice upon creation
Following the new design proposal to improve the restore codepath when
migrating a VM, all virtio devices are supplied with an optional state
they can use to restore from. The restore() implementation every device
was providing has been removed in order to prevent from going through
the restoration twice.

Here is the list of devices now following the new restore design:

- Block (virtio-block)
- Net (virtio-net)
- Rng (virtio-rng)
- Fs (vhost-user-fs)
- Blk (vhost-user-block)
- Net (vhost-user-net)
- Pmem (virtio-pmem)
- Vsock (virtio-vsock)
- Mem (virtio-mem)
- Balloon (virtio-balloon)
- Watchdog (virtio-watchdog)
- Vdpa (vDPA)
- Console (virtio-console)
- Iommu (virtio-iommu)

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
2022-10-24 14:17:08 +02:00

101 lines
3.2 KiB
Rust

// Copyright © 2022 Intel Corporation
//
// SPDX-License-Identifier: Apache-2.0
#![no_main]
use libfuzzer_sys::fuzz_target;
use seccompiler::SeccompAction;
use std::os::unix::io::{AsRawFd, FromRawFd};
use std::sync::Arc;
use virtio_devices::{VirtioDevice, VirtioInterrupt, VirtioInterruptType};
use virtio_queue::{Queue, QueueT};
use vm_memory::{bitmap::AtomicBitmap, Bytes, GuestAddress, GuestMemoryAtomic};
use vmm_sys_util::eventfd::{EventFd, EFD_NONBLOCK};
type GuestMemoryMmap = vm_memory::GuestMemoryMmap<AtomicBitmap>;
const QUEUE_DATA_SIZE: usize = 4;
const MEM_SIZE: usize = 256 * 1024 * 1024;
// Max entries in the queue.
const QUEUE_SIZE: u16 = 256;
// Guest physical address for descriptor table.
const DESC_TABLE_ADDR: u64 = 0;
const DESC_TABLE_SIZE: u64 = 16_u64 * QUEUE_SIZE as u64;
// Guest physical address for available ring
const AVAIL_RING_ADDR: u64 = DESC_TABLE_ADDR + DESC_TABLE_SIZE;
const AVAIL_RING_SIZE: u64 = 6_u64 + 2 * QUEUE_SIZE as u64;
// Guest physical address for used ring (requires to 4-bytes aligned)
const USED_RING_ADDR: u64 = (AVAIL_RING_ADDR + AVAIL_RING_SIZE + 3) & !3_u64;
fuzz_target!(|bytes| {
if bytes.len() < QUEUE_DATA_SIZE || bytes.len() > (QUEUE_DATA_SIZE + MEM_SIZE) {
return;
}
let mut watchdog = virtio_devices::Watchdog::new(
"fuzzer_watchdog".to_owned(),
EventFd::new(EFD_NONBLOCK).unwrap(),
SeccompAction::Allow,
EventFd::new(EFD_NONBLOCK).unwrap(),
None,
)
.unwrap();
let queue_data = &bytes[..QUEUE_DATA_SIZE];
let mem_bytes = &bytes[QUEUE_DATA_SIZE..];
// Setup the virt queue with the input bytes
let q = setup_virt_queue(queue_data.try_into().unwrap());
// Setup the guest memory with the input bytes
let mem = GuestMemoryMmap::from_ranges(&[(GuestAddress(0), MEM_SIZE)]).unwrap();
if mem.write_slice(mem_bytes, GuestAddress(0 as u64)).is_err() {
return;
}
let guest_memory = GuestMemoryAtomic::new(mem);
let evt = EventFd::new(0).unwrap();
let queue_evt = unsafe { EventFd::from_raw_fd(libc::dup(evt.as_raw_fd())) };
// Kick the 'queue' event before activate the watchdog device
queue_evt.write(1).unwrap();
watchdog
.activate(
guest_memory,
Arc::new(NoopVirtioInterrupt {}),
vec![(0, q, evt)],
)
.ok();
// Wait for the events to finish and watchdog device worker thread to return
watchdog.wait_for_epoll_threads();
});
pub struct NoopVirtioInterrupt {}
impl VirtioInterrupt for NoopVirtioInterrupt {
fn trigger(&self, _int_type: VirtioInterruptType) -> std::result::Result<(), std::io::Error> {
Ok(())
}
}
fn setup_virt_queue(bytes: &[u8; QUEUE_DATA_SIZE]) -> Queue {
let mut q = Queue::new(QUEUE_SIZE).unwrap();
q.set_next_avail(bytes[0] as u16); // 'u8' is enough given the 'QUEUE_SIZE' is small
q.set_next_used(bytes[1] as u16);
q.set_event_idx(bytes[2] % 2 != 0);
q.set_size(bytes[3] as u16 % QUEUE_SIZE);
q.try_set_desc_table_address(GuestAddress(DESC_TABLE_ADDR))
.unwrap();
q.try_set_avail_ring_address(GuestAddress(AVAIL_RING_ADDR))
.unwrap();
q.try_set_used_ring_address(GuestAddress(USED_RING_ADDR))
.unwrap();
q.set_ready(true);
q
}