Re: [libvirt PATCH v2 03/81] Introduce VIR_DOMAIN_RUNNING_POSTCOPY_FAILED

On Mon, Jun 06, 2022 at 14:29:20 +0200, Peter Krempa wrote: > On Wed, Jun 01, 2022 at 14:49:03 +0200, Jiri Denemark wrote: > > This new "post-copy failed" reason for the running state will be used on > > the destination host when post-copy migration fails while the domain is > > already running there. > > > > Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com&gt; > > --- > > > > Notes: > > Version 2: > > - documented both VIR_DOMAIN_RUNNING_POSTCOPY_FAILED and > > VIR_DOMAIN_PAUSED_POSTCOPY_FAILED possibilities on the destination > > > > examples/c/misc/event-test.c | 3 +++ > > include/libvirt/libvirt-domain.h | 2 ++ > > src/conf/domain_conf.c | 1 + > > src/libvirt-domain.c | 26 +++++++++++++++++++------- > > src/qemu/qemu_domain.c | 3 +++ > > tools/virsh-domain-event.c | 3 ++- > > tools/virsh-domain-monitor.c | 1 + > > 7 files changed, 31 insertions(+), 8 deletions(-) > > [...] > > > diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c > > index e3ced700b8..b9f1d73d5a 100644 > > --- a/src/libvirt-domain.c > > +++ b/src/libvirt-domain.c > > @@ -9764,10 +9764,16 @@ virDomainMigrateGetMaxSpeed(virDomainPtr domain, > > * at most once no matter how fast it changes. On the other hand once the > > * guest is running on the destination host, the migration can no longer be > > * rolled back because none of the hosts has complete state. If this happens, > > - * libvirt will leave the domain paused on both hosts with > > - * VIR_DOMAIN_PAUSED_POSTCOPY_FAILED reason. It's up to the upper layer to > > - * decide what to do in such case. Because of this, libvirt will refuse to > > - * cancel post-copy migration via virDomainAbortJob. > > + * libvirt will leave the domain paused on the source host with > > + * VIR_DOMAIN_PAUSED_POSTCOPY_FAILED reason. The domain on the destination host > > + * will either remain running with VIR_DOMAIN_RUNNING_POSTCOPY_FAILED reason if > > + * libvirt loses control over the migration (e.g., the daemon is restarted or > > + * libvirt connection is broken) while QEMU is still able to continue migrating > > + * memory pages from the source to the destination or it will be paused with > > + * VIR_DOMAIN_PAUSED_POSTCOPY_FAILED if even the connection between QEMU > > + * processes gets broken. It's up to the upper layer to decide what to do in > > I presume this bit is still up for discussion, right? Currently with the > RFC patch 81 you'd attempt to pause it but qemu will break anyways IIUC. > > If that is the case, this should for now document it properly. Never mind. I've re-read the paragraph (and code in next patch and noticed that it's meant on the source side, which makes sense.