On Wed, Mar 12, 2025 at 17:17:59 +0000, Daniel P. Berrangé wrote:
The preserving of state (ie running VMs) requires a fully functional daemon and hypervisor driver. If any part has started shutting down then saving state may fail, or worse, hang.
The current shutdown sequence does not guarantee safe ordering, as we synchronize with the state saving thread only after the hypervisor driver has had its 'shutdownPrepare' callback invoked. In the case of QEMU this means that worker threads processing monitor events may well have been stopped.
This implements a full state machine that has a well defined ordering that an earlier commit documented as the desired semantics.
With this change, nothing will start shutting down if the state saving thread is still running.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/rpc/virnetdaemon.c | 107 ++++++++++++++++++++++++++++++----------- 1 file changed, 80 insertions(+), 27 deletions(-)
Reviewed-by: Peter Krempa <pkrempa@redhat.com>