From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mikhail Sennikovskii Subject: Re: Windows 2008 Guest BSODS with CLOCK_WATCHDOG_TIMEOUT on VM migration Date: Thu, 29 Jan 2015 08:57:31 +0100 Message-ID: <54C9E7EB.5090402@profitbricks.com> References: <20150118030317.23598.27686.malonedeb@chaenomeles.canonical.com> <54C254AF.7010101@profitbricks.com> <54C798D0.6010600@profitbricks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: KVM To: Jidong Xiao Return-path: Received: from mail-wi0-f170.google.com ([209.85.212.170]:42664 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753140AbbA2H5h (ORCPT ); Thu, 29 Jan 2015 02:57:37 -0500 Received: by mail-wi0-f170.google.com with SMTP id bs8so6133284wib.1 for ; Wed, 28 Jan 2015 23:57:36 -0800 (PST) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: Hi Jidong, right, this issue is SMP-specific. Mikhail On 27.01.2015 20:09, Jidong Xiao wrote: > On Tue, Jan 27, 2015 at 5:55 AM, Mikhail Sennikovskii > wrote: >> Hi all, >> >> I've posted the bolow mail to the qemu-dev mailing list, but I've got no >> response there. >> That's why I decided to re-post it here as well, and besides that I think >> this could be a kvm-specific issue as well. >> >> Some additional thing to note: >> I can reproduce the issue on my Debian 7 with 3.16.0-0.bpo.4-amd64 kernel as >> well. >> I would typically use a max_downtime adjusted to 1 second instead of default >> 30 ms. >> I also noticed that the issue happens much more rarelly if I increase the >> migration bandwidth, i.e. like >> >> diff --git a/migration.c b/migration.c >> index 26f4b65..d2e3b39 100644 >> --- a/migration.c >> +++ b/migration.c >> @@ -36,7 +36,7 @@ enum { >> MIG_STATE_COMPLETED, >> }; >> >> -#define MAX_THROTTLE (32 << 20) /* Migration speed throttling */ >> +#define MAX_THROTTLE (90 << 20) /* Migration speed throttling */ >> >> Like I said below, I would be glad to provide you with any additional >> information. >> >> Thanks, >> Mikhail >> > Hi, Mikhail, > > So if you choose to use one vcpu, instead of smp, this issue would not > happen, right? > > -Jidong > >> On 23.01.2015 15:03, Mikhail Sennikovskii wrote: >>> Hi all, >>> >>> I'm running a slitely modified migration over tcp test in virt-test, which >>> does a migration from one "smp=2" VM to another on the same host over TCP, >>> and exposes some dummy CPU load inside the GUEST while migration, and >>> after a series of runs I'm alwais getting a CLOCK_WATCHDOG_TIMEOUT BSOD >>> inside the guest, >>> which happens when >>> " >>> An expected clock interrupt was not received on a secondary processor in >>> an >>> MP system within the allocated interval. This indicates that the specified >>> processor is hung and not processing interrupts. >>> " >>> >>> This seems to happen with any qemu version I've tested (1.2 and above, >>> including upstream), >>> and I was testing it with 3.13.0-44-generic kernel on my Ubuntu 14.04.1 >>> LTS with SMP4 host, as well as on 3.12.26-1 kernel with Debian 6 with SMP6 >>> host. >>> >>> One thing I noticed is that exposing a dummy CPU load on the HOST (like >>> running multiple instances of the "while true; do false; done" script) in >>> parallel with doing migration makes the issue to be quite easily >>> reproducible. >>> >>> >>> Looking inside the windows crash dump, the second CPU is just running at >>> IRQL 0, and it aparently not hung, as Windows is able to save its state in >>> the crash dump correctly, which assumes running some code on it. >>> So this aparently seems to be some timing issue (like host scheduler does >>> not schedule the thread executing secondary CPU's code in time). >>> >>> Could you give me some insight on this, i.e. is there a way to customize >>> QEMU/KVM to avoid such issue? >>> >>> If you think this might be a qemu/kvm issue, I can provide you any info, >>> like windows crash dumps, or the test-case to reproduce this. >>> >>> >>> qemu is started as: >>> >>> from-VM: >>> >>> qemu-system-x86_64 \ >>> -S \ >>> -name 'virt-tests-vm1' \ >>> -sandbox off \ >>> -M pc-1.0 \ >>> -nodefaults \ >>> -vga std \ >>> -chardev >>> socket,id=qmp_id_qmp1,path=/tmp/monitor-qmp1-20150123-112624-aFZmIkNT,server,nowait >>> \ >>> -mon chardev=qmp_id_qmp1,mode=control \ >>> -chardev >>> socket,id=serial_id_serial0,path=/tmp/serial-serial0-20150123-112624-aFZmIkNT,server,nowait >>> \ >>> -device isa-serial,chardev=serial_id_serial0 \ >>> -chardev >>> socket,id=seabioslog_id_20150123-112624-aFZmIkNT,path=/tmp/seabios-20150123-112624-aFZmIkNT,server,nowait >>> \ >>> -device >>> isa-debugcon,chardev=seabioslog_id_20150123-112624-aFZmIkNT,iobase=0x402 \ >>> -device ich9-usb-uhci1,id=usb1,bus=pci.0,addr=03 \ >>> -drive id=drive_image1,if=none,file=/path/to/image.qcow2 \ >>> -device >>> virtio-blk-pci,id=image1,drive=drive_image1,bootindex=0,bus=pci.0,addr=04 \ >>> -device >>> virtio-net-pci,mac=9a:74:75:76:77:78,id=idFdaC4M,vectors=4,netdev=idKFZNXH,bus=pci.0,addr=05 >>> \ >>> -netdev >>> user,id=idKFZNXH,hostfwd=tcp::5000-:22,hostfwd=tcp::5001-:10023 \ >>> -m 2G \ >>> -smp 2,maxcpus=2,cores=1,threads=1,sockets=2 \ >>> -cpu phenom \ >>> -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1 \ >>> -vnc :0 \ >>> -rtc base=localtime,clock=host,driftfix=none \ >>> -boot order=cdn,once=c,menu=off \ >>> -enable-kvm >>> >>> to-VM: >>> >>> qemu-system-x86_64 \ >>> -S \ >>> -name 'virt-tests-vm1' \ >>> -sandbox off \ >>> -M pc-1.0 \ >>> -nodefaults \ >>> -vga std \ >>> -chardev >>> socket,id=qmp_id_qmp1,path=/tmp/monitor-qmp1-20150123-112750-VehjvEqK,server,nowait >>> \ >>> -mon chardev=qmp_id_qmp1,mode=control \ >>> -chardev >>> socket,id=serial_id_serial0,path=/tmp/serial-serial0-20150123-112750-VehjvEqK,server,nowait >>> \ >>> -device isa-serial,chardev=serial_id_serial0 \ >>> -chardev >>> socket,id=seabioslog_id_20150123-112750-VehjvEqK,path=/tmp/seabios-20150123-112750-VehjvEqK,server,nowait >>> \ >>> -device >>> isa-debugcon,chardev=seabioslog_id_20150123-112750-VehjvEqK,iobase=0x402 \ >>> -device ich9-usb-uhci1,id=usb1,bus=pci.0,addr=03 \ >>> -drive id=drive_image1,if=none,file=/path/to/image.qcow2 \ >>> -device >>> virtio-blk-pci,id=image1,drive=drive_image1,bootindex=0,bus=pci.0,addr=04 \ >>> -device >>> virtio-net-pci,mac=9a:74:75:76:77:78,id=idI46M9C,vectors=4,netdev=idl9vRQt,bus=pci.0,addr=05 >>> \ >>> -netdev >>> user,id=idl9vRQt,hostfwd=tcp::5002-:22,hostfwd=tcp::5003-:10023 \ >>> -m 2G \ >>> -smp 2,maxcpus=2,cores=1,threads=1,sockets=2 \ >>> -cpu phenom \ >>> -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1 \ >>> -vnc :1 \ >>> -rtc base=localtime,clock=host,driftfix=none \ >>> -boot order=cdn,once=c,menu=off \ >>> -enable-kvm \ >>> -incoming tcp:0:5200 >>> >>> >>> Thanks, >>> Mikhail >> >> -- >> To unsubscribe from this list: send the line "unsubscribe kvm" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html