On Mon, Oct 28, 2013 at 01:03:49PM -0400, Cole Robinson wrote: > On 10/28/2013 07:52 AM, Daniel P. Berrange wrote: > > From: "Daniel P. Berrange" <berrange@xxxxxxxxxx> > > > > The following sequence > > > > 1. Define a persistent QMEU guest > > 2. Start the QEMU guest > > 3. Stop libvirtd > > 4. Kill the QEMU process > > 5. Start libvirtd > > 6. List persistent guets > > > > At the last step, the previously running persistent guest > > will be missing. This is because of a race condition in the > > QEMU driver startup code. It does > > > > 1. Load all VM state files > > 2. Spawn thread to reconnect to each VM > > 3. Load all VM config files > > > > Only at the end of step 3, does the 'virDomainObjPtr' get > > marked as "persistent". There is therefore a window where > > the thread reconnecting to the VM will remove the persistent > > VM from the list. > > > > The easy fix is to simply switch the order of steps 2 & 3. > > > > Signed-off-by: Daniel P. Berrange <berrange@xxxxxxxxxx> > > --- > > src/qemu/qemu_driver.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c > > index c613967..9c3daad 100644 > > --- a/src/qemu/qemu_driver.c > > +++ b/src/qemu/qemu_driver.c > > @@ -816,8 +816,6 @@ qemuStateInitialize(bool privileged, > > > > conn = virConnectOpen(cfg->uri); > > > > - qemuProcessReconnectAll(conn, qemu_driver); > > - > > /* Then inactive persistent configs */ > > if (virDomainObjListLoadAllConfigs(qemu_driver->domains, > > cfg->configDir, > > @@ -828,6 +826,7 @@ qemuStateInitialize(bool privileged, > > NULL, NULL) < 0) > > goto error; > > > > + qemuProcessReconnectAll(conn, qemu_driver); > > > > virDomainObjListForEach(qemu_driver->domains, > > qemuDomainSnapshotLoad, > > > > I tried testing this patch to see if it would fix: > > https://bugzilla.redhat.com/show_bug.cgi?id=1015246 > > from current master I did: > > git revert a924d9d083c215df6044387057c501d9aa338b96 > reproduce the bug > git am <your-patch> > > But the daemon won't even start up after your patch is built: > > (gdb) bt > #0 qemuMonitorOpen (vm=vm@entry=0x7fffd4211090, config=0x0, json=false, > cb=cb@entry=0x7fffddcae720 <monitorCallbacks>, > opaque=opaque@entry=0x7fffd419b840) at qemu/qemu_monitor.c:852 > #1 0x00007fffdda1083d in qemuConnectMonitor ( > driver=driver@entry=0x7fffd419b840, vm=vm@entry=0x7fffd4211090, > logfd=logfd@entry=-1) at qemu/qemu_process.c:1412 > #2 0x00007fffdda1685a in qemuProcessReconnect ( > opaque=opaque@entry=0x7fffd422fef0) at qemu/qemu_process.c:3086 > #3 0x00007ffff7528dce in virThreadHelper (data=<optimized out>) > at util/virthreadpthread.c:161 > #4 0x00007ffff4782f33 in start_thread (arg=0x7fffcb7fe700) > at pthread_create.c:309 > #5 0x00007ffff40a9ead in clone () > at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 What is this trace showing ? or rather what is the error reported when it fails to start ? Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list