From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48991) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WVHVk-0002Xw-6N for qemu-devel@nongnu.org; Wed, 02 Apr 2014 05:31:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WVHVb-0005FO-Ou for qemu-devel@nongnu.org; Wed, 02 Apr 2014 05:31:08 -0400 Received: from mx.beyond.pl ([92.43.117.49]:60287) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WVHVb-0005FA-Es for qemu-devel@nongnu.org; Wed, 02 Apr 2014 05:30:59 -0400 Message-ID: <533BD8CE.9060002@beyond.pl> Date: Wed, 02 Apr 2014 11:30:54 +0200 From: =?UTF-8?B?TWFyY2luIEdpYnXFgmE=?= MIME-Version: 1.0 References: <20140327225242.GA5005@onthe.net.au> <5334B44E.4080300@beyond.pl> <20140327235918.GA7689@onthe.net.au> <533929D3.30109@beyond.pl> <20140402054144.GA31323@onthe.net.au> <533BCE40.8060908@beyond.pl> <20140402090450.GA2586@work-vm> In-Reply-To: <20140402090450.GA2586@work-vm> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Unresponsive linux guest once migrated List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: qemu-devel@nongnu.org > Can you give: > 1) A backtrace from the guest > thread apply all bt full > in gdb You mean from gdb attached to hanged guest? I'll try to get it. From what I remember it looks rather "normal" - busy executing guest code. > 2) What's the earliest/newest qemu versions you've seen this on? 1.4 - 1.6 Don't know about earlier versions because I didn't use migration on them. Haven't tried 1.7 yet (I know about XBZRLE fixes, but it happened without it as well...). > 3) What guest OS are you running? All flavors of Centos, Ubuntu, Redhat, etc. Also Windows. But never seen a crash with Windows so far. Seems that few people who also have this issue, reports success with kvmclock disabled (either in qemu or kernel command line). > 4) What host OS are you running? Distro is Gentoo based (with no crazy compiler options). I've been using kernel 3.4 - 3.10. > 5) What CPU are you running on? AMD Opteron(tm) Processor 6164 HE > 6) What does your qemu command line look like? Example VM: /usr/bin/qemu-system-x86_64 -machine accel=kvm -name 3b5e37ea-04be-4a6b-8d63-f1a5853f2138 -S -machine pc-i440fx-1.5,accel=kvm,usb=off -cpu qemu64,+misalignsse,+abm,+lahf_lm,+rdtscp,+popcnt,+x2apic,-svm,+kvmclock -m 1024 -realtime mlock=on -smp 2,sockets=4,cores=12,threads=1 -uuid 3b5e37ea-04be-4a6b-8d63-f1a5853f2138 -smbios type=0,vendor=HAL 9000 -smbios type=1,manufacturer=cloud -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/3b5e37ea-04be-4a6b-8d63-f1a5853f2138.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,clock=vm,driftfix=slew -no-hpet -no-kvm-pit-reinjection -no-shutdown -boot menu=off -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x4 -drive file=/dev/stor1c/2e7fd7aa-8588-47ed-a091-af2b81c9e935,if=none,id=drive-virtio-disk0,format=raw,cache=none,aio=native,bps_rd=57671680,bps_wr=57671680,iops_rd=275,iops_wr=275 -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=2 -drive if=none,id=drive-ide0-0-0,readonly=on,format=raw -device ide-cd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 -netdev tap,fd=22,id=hostnet0,vhost=on,vhostfd=27 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:11:11:11:11,bus=pci.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -chardev socket,id=charchannel0,path=/var/lib/libvirt/qemu/f16x86_64.agent,server,nowait -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.1 -device usb-tablet,id=input0 -vnc 0.0.0.0:4,password -vga cirrus -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6 -sandbox on I've tried playing with different CPU model (Opteron_G3) and flags, it didn't make any difference. > 7) How exactly are you migrating? Via libvirt live migration. Seen it with and without XBZRLE enabled. > 8) You talk about having to wait a few hours to trigger it - do > you have a more exact description of a test? Yes, that's where it gets weird. I've never seen this on fresh VM. It needs to be idle for couple of hours at least. And even then it doesn't always hang. > 9) Is there any output from qemu stderr/stdout in your qemu logs? Nothing unusual. From QEMU point of view guest is up and running. Only its OS is hanged (but not panicked, there is no backtrace, oops or BUG on its screen). -- mg