Vincent Thomas e5dbf5242e virtio-devices: Make pause idempotent to prevent deadlock ...

Previously, calling pause() when already paused would wait on a barrier
for worker threads that were already parked, causing a deadlock.

This situation occurs when the VMM thread holds a device mutex while
calling an operation that triggers pause(), and a vCPU thread
simultaneously needs that same mutex for MMIO access. With slow I/O
backends (like RBD/Ceph), the timing window for this race is larger,
making the deadlock more likely to occur, see [0].

Make pause() idempotent by checking the paused state atomically and
returning early if already paused, avoiding the barrier wait.

[0] https://github.com/cloud-hypervisor/cloud-hypervisor/pull/7948#discussion_r305052509

Signed-off-by: Vincent Thomas <vincent@v-thomas.com>

2026-04-17 07:57:35 +00:00

..

src

virtio-devices: Make pause idempotent to prevent deadlock

2026-04-17 07:57:35 +00:00

build.rs

build: Add "fuzzing" as a valid cfg(..) attribute

2024-05-08 08:10:28 +00:00

Cargo.toml

virtio-devices: Add set_notifier() method to VirtioInterrupt

2026-03-18 09:25:27 +00:00