Re: [libvirt] [PATCH 5/7] qemu: Wire up PR_MANAGER_STATUS_CHANGED event

On 07/04/2018 01:42 PM, Peter Krempa wrote: > On Wed, Jul 04, 2018 at 12:46:53 +0200, Michal Privoznik wrote: >> This event is emitted on the monitor if one of pr-managers lost >> connection to its pr-helper process. What libvirt needs to do is >> restart the pr-helper process iff it corresponds to managed >> pr-manager. >> >> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; >> --- >> src/qemu/qemu_monitor.c | 15 +++++++++++++ >> src/qemu/qemu_monitor.h | 11 +++++++++ >> src/qemu/qemu_monitor_json.c | 23 +++++++++++++++++++ >> src/qemu/qemu_process.c | 53 ++++++++++++++++++++++++++++++++++++++++++++ >> 4 files changed, 102 insertions(+) > > [...] > > >> diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c >> index f200729cb1..94b7de76d7 100644 >> --- a/src/qemu/qemu_process.c >> +++ b/src/qemu/qemu_process.c >> @@ -1615,6 +1615,58 @@ qemuProcessHandleDumpCompleted(qemuMonitorPtr mon ATTRIBUTE_UNUSED, >> } >> >> >> +static int >> +qemuProcessHandlePRManagerStatusChanged(qemuMonitorPtr mon ATTRIBUTE_UNUSED, >> + virDomainObjPtr vm, >> + const char *prManager, >> + bool connected, >> + void *opaque ATTRIBUTE_UNUSED) >> +{ >> + qemuDomainObjPrivatePtr priv; >> + size_t i; >> + int ret = -1; >> + >> + virObjectLock(vm); >> + >> + VIR_DEBUG("pr-manager %s status changed for domain %p %s connected=%d", >> + prManager, vm, vm->def->name, connected); >> + >> + if (connected) { >> + /* Connect events are boring. */ >> + ret = 0; >> + goto cleanup; >> + } >> + /* Disconnect events are more interesting. */ >> + >> + for (i = 0; i < vm->def->ndisks; i++) { >> + const char *mgralias; >> + >> + mgralias = virStorageSourceChainGetManagedPRAlias(vm->def->disks[i]->src); >> + >> + if (STREQ_NULLABLE(prManager, mgralias)) >> + break; > > I'm not a fan of this. We always know which is the managed alias Do we? I thought the whole point of storing it in source private data was to make it independent of qemuDomainGetManagedPRAlias(). Imagine I started a domain with pr-manager.alias = pr-helper0. Then restarted libvirtd to upgrade it. This new version has, however, pr-helper1 as default alias (because reasons). Then all of a sudden I receive this event with alias pr-helper0 (because that is how I started the domain). I can't do plain: STREQ(prManager, qemuDomainGetManagedPRAlias()) can I?