Re: [libvirt] [PATCH 1/3] qemu: always call qemuInterfaceStartDevices() when starting CPUs

The patch that added qemuInterfaceStartDevices() (upstream commit 82977058f5b1d143a355079900029e9cbfee2fe4) had an extra conditional to prevent calling it if the reason for starting the CPUs was VIR_DOMAIN_RUNNING_UNPAUSED or VIR_DOMAIN_RUNNING_SAVE_CANCELED. This was put in by the author as the result of a reviewer asking if it was necessary to ifup the interfaces in *all* occasions (because these were the two cases where the CPU would have already been started (and stopped) once, so the interface would already be ifup'ed). It turns out that, as long as there is no corresponding qemuInterfaceStopDevices() to ifdown the interfaces anytime the CPUs are stopped, neglecting to ifup when reason is RUNNING_UNPAUSED or RUNNING_SAVE_CANCELED doesn't cause any problems (because it just happens that the interface will have already been ifup'ed by a prior call when the CPU was previously started for some other reason). However, it also doesn't *help*, and there will soon be a qemuInterfaceStopDevices() function which *will* ifdown these interfaces when the guest CPUs are stopped, and once that is done, the interfaces will be left down in some cases when they should be up (for example, if a domain is paused and then unpaused). So, this patch is removing the condition in favor of always calling qemuInterfaeStartDevices() when the guest CPUs are started. This patch (and the aforementioned patch) resolve: https://bugzilla.redhat.com/show_bug.cgi?id=1081461 --- src/qemu/qemu_process.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index ab4df9b..0028283 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -3126,9 +3126,7 @@ qemuProcessStartCPUs(virQEMUDriverPtr driver, virDomainObjPtr vm, virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver); /* Bring up netdevs before starting CPUs */ - if (reason != VIR_DOMAIN_RUNNING_UNPAUSED && - reason != VIR_DOMAIN_RUNNING_SAVE_CANCELED && - qemuInterfaceStartDevices(vm->def) < 0) + if (qemuInterfaceStartDevices(vm->def) < 0) goto cleanup; VIR_DEBUG("Using lock state '%s'", NULLSTR(priv->lockState));