Re: [libvirt] [PATCH] qemu: Refresh state before starting the VCPUs

On Mon, Feb 04, 2019 at 13:36:24 +0100, Marc Hartmayer wrote: > For normal starts (no incoming migration) the refresh of the QEMU > state must be done before the VCPUs getting started since otherwise > there might be a race condition between a possible shutdown of the > guest OS and the QEMU monitor queries. > > This fixes "qemu: migration: Refresh device information after > transferring state" (93db7eea1b864). > > Signed-off-by: Marc Hartmayer <mhartmay(a)linux.ibm.com&gt; > --- > src/qemu/qemu_process.c | 20 +++++++++++--------- > 1 file changed, 11 insertions(+), 9 deletions(-) > > diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c > index dace5aaca102..2a3763f40d49 100644 > --- a/src/qemu/qemu_process.c > +++ b/src/qemu/qemu_process.c > @@ -6929,10 +6929,17 @@ qemuProcessStart(virConnectPtr conn, > } > relabel = true; > > - if (incoming && > - incoming->deferredURI && > - qemuMigrationDstRun(driver, vm, incoming->deferredURI, asyncJob) < 0) > - goto stop; > + if (incoming) { > + if (incoming->deferredURI && > + qemuMigrationDstRun(driver, vm, incoming->deferredURI, asyncJob) < 0) > + goto stop; > + } else { This logic does not seem right ...

> + /* Refresh state of devices from QEMU. During migration this > + * needs to happen after the state information is fully > + * transferred. */ as this comment clearly states that this should happen after migration.

Here it would happen only when migration is not done.

> + if (qemuProcessRefreshState(driver, vm, asyncJob) < 0) > + goto stop; > + } > > if (qemuProcessFinishStartup(driver, vm, asyncJob, > !(flags & VIR_QEMU_PROCESS_START_PAUSED), > @@ -6945,11 +6952,6 @@ qemuProcessStart(virConnectPtr conn, > /* Keep watching qemu log for errors during incoming migration, otherwise > * unset reporting errors from qemu log. */ > qemuMonitorSetDomainLog(priv->mon, NULL, NULL, NULL); > - > - /* Refresh state of devices from qemu. During migration this needs to > - * happen after the state information is fully transferred. */ > - if (qemuProcessRefreshState(driver, vm, asyncJob) < 0) > - goto stop; > } > > ret = 0; > -- > 2.17.0 >