On Mon, Jul 20, 2026 at 01:22:41PM +0300, Andrey Drobyshev wrote:
From: Pavel Tikhomirov <[email protected]>This ioctl is needed for QEMU's CPR (checkpoint-restore) migration of the guest with vhost-vsock device. For this to work, we need to reset the device ownership on the source side by calling RESET_OWNER, and then claim it on the dest side by calling SET_OWNER. We expect not to lose any AF_VSOCK connection while this happens. To that end, unlike the release path, RESET_OWNER keeps the guest CID hashed: established connections survive, and host sends issued while the device is between owners simply stay on send_pkt_queue until the next device start drains them. Since the device stays reachable through the CID hash, the lockless send/cancel paths can race with the worker teardown in vhost_workers_free(). The previous commit ("vhost: synchronize with RCU readers when freeing workers") makes that safe. Signed-off-by: Pavel Tikhomirov <[email protected]> Signed-off-by: Andrey Drobyshev <[email protected]> --- drivers/vhost/vsock.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)
Reviewed-by: Stefano Garzarella <[email protected]>
