On Tue, Oct 08, 2024 at 03:12:32PM -0400, Steven Sistare wrote: > > This is slightly tricky part and would be nice to be documented somewhere, > > perhaps starting from in the commit message. > > I will extend the block comment in qmp_migrate: > > /* > * For cpr-transfer, the target may not be listening yet on the migration > * channel, because first it must finish cpr_load_state. The target tells > * us it is listening by closing the cpr-state socket. Wait for that HUP > * event before connecting in qmp_migrate_finish. > * > * The HUP could occur because the target fails while reading CPR state, > * in which case the target will not listen for the incoming migration > * connection, so qmp_migrate_finish will fail to connect, and then > recover. > */
Yes this is better, thanks. > > > Then the error will say "failed to connect to destination QEMU" hiding the > > real failure (cpr save/load failed), right? That's slightly a pity. > > Yes, but destination qemu will also emit a more specific message. True. > > > I'm OK with the HUP as of now, but if you care about accurate CPR-stage > > error reporting, then feel free to draft something else in the next post. > > I'll think about it, but to get cpr into 9.2, this will probably need to be > deferred as a future enhancement. Yep that's OK. -- Peter Xu
