On 10/29/2013 10:25 AM, Daniel P. Berrange wrote:
On Mon, Oct 28, 2013 at 01:22:39PM -0400, Cole Robinson wrote:
On 10/28/2013 01:14 PM, Daniel P. Berrange wrote:
On Mon, Oct 28, 2013 at 01:08:45PM -0400, Cole Robinson wrote:
On 10/28/2013 01:06 PM, Daniel P. Berrange wrote:
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@redhat.com> > > 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@redhat.com> > --- > 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
Sorry for not being clear: The daemon crashes, that's the backtrace.
Hmm config is NULL - does the state XML files not include the monitor info perhaps ?
I see:
pidfile for busted VM in /var/run/libvirt/qemu nothing in /var/cache/libvirt/qemu no state that I can see in /var/lib/libvirt/qemu
But I'm not sure where it's supposed to be stored.
FWIW reproducing this state was pretty simple: revert a924d9d083c215df6044387057c501d9aa338b96, edit an existing x86 guest to remove all <video> and <graphics> devices, start the guest, libvirtd crashes.
Ok, I believe you probably have SELinux disabled on your machine or in libvirtd. With SELinux enabled you hit another bug first
2013-10-29 13:50:11.711+0000: 17579: error : qemuConnectMonitor:1401 : Failed to set security context for monitor for rhel6x86_64
which prevents hitting the crash you report. The fix is the same in both cases - we must skip VMs with PID of zero. I've sent a v2 patch.
Hmm, selinux is permissive here but not disabled. But I'll try your patches and report back. Thanks, Cole