From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bandan Das Subject: Re: Hang on reboot in FreeBSD guest on Linux KVM host Date: Mon, 22 Jun 2015 17:48:48 -0400 Message-ID: References: <6DBD3DBB-24B1-4564-B524-E8E73508BBC5@jnielsen.net> <42870B81-CA29-4161-9BCE-F6D6020C3D2C@jnielsen.net> <539F1DC0.4020604@redhat.com> <4F14D859-D641-4AB5-B749-83D9D82F1DEA@jnielsen.net> <539FC243.2070906@redhat.com> <20140617060500.GA20764@minantech.com> <6850B127-F16B-465F-BDDB-BA3F99B9E446@jnielsen.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Gleb Natapov , Paolo Bonzini , "kvm\@vger.kernel.org" , John Nielsen To: John Nielsen Return-path: Received: from mx1.redhat.com ([209.132.183.28]:56971 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751507AbbFVVsv convert rfc822-to-8bit (ORCPT ); Mon, 22 Jun 2015 17:48:51 -0400 In-Reply-To: <6850B127-F16B-465F-BDDB-BA3F99B9E446@jnielsen.net> (John Nielsen's message of "Mon, 22 Jun 2015 12:02:29 -0600") Sender: kvm-owner@vger.kernel.org List-ID: John Nielsen writes: > On Jun 17, 2014, at 10:48 AM, John Nielsen wrote= : > >> On Jun 17, 2014, at 12:05 AM, Gleb Natapov wrote: >>=20 >>> On Tue, Jun 17, 2014 at 06:21:23AM +0200, Paolo Bonzini wrote: >>>> Il 16/06/2014 18:47, John Nielsen ha scritto: >>>>> On Jun 16, 2014, at 10:39 AM, Paolo Bonzini >>>>> wrote: >>>>>=20 >>>>>> Il 16/06/2014 18:09, John Nielsen ha scritto: >>>>>>>>> The only substantial difference on the hardware side is the >>>>>>>>> CPU. The hosts where the problem occurs use "Intel(R) >>>>>>>>> Xeon(R) CPU E5-2650 v2 @ 2.60GHz", while the hosts that don't >>>>>>>>> show the problem use the prior revision, "Intel(R) Xeon(R) >>>>>>>>> CPU E5-2650 0 @ 2.00GHz". >>>>>> Can you do "grep . /sys/module/kvm_intel/parameters/*" on both >>>>>> hosts please? >>>>> No differences that I can see. Output below. >>>> Not really: >>>>=20 >>>>> Working host: Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz # grep >>>>> . /sys/module/kvm_intel/parameters/* >>>>> /sys/module/kvm_intel/parameters/enable_apicv:N >>>>>=20 >>>>> Problem host: Intel(R) Xeon(R) CPU E5-2650 v2 @ 2.60GHz # grep >>>>> . /sys/module/kvm_intel/parameters/* >>>>> /sys/module/kvm_intel/parameters/enable_apicv:Y >>>> So we have a clue. Let me study the code more, I'll try to get >>>> back with a suggestion. >> Wow, can't believe I missed that. Good catch! >>=20 >>> Does disabling apicv on E5-2650 v2 make reboot problem go away? >> Yes it does! >>=20 >> # modprobe kvm_intel /sys/module/kvm_intel/parameters/enable_apicv:Y >> # /usr/bin/qemu-system-x86_64 -machine accel=3Dkvm -name bsdtest -m >> 512 -smp 2,sockets=3D1,cores=3D1,threads=3D2 -drive >> file=3D./20140613_FreeBSD_9.2-RELEASE_ufs.qcow2,if=3Dnone,id=3Ddrive= 0,format=3Dqcow2 >> -device virtio-blk-pci,scsi=3Doff,drive=3Ddrive0 -vnc 0.0.0.0:0 -net >> none >>=20 >> [problem occurs] >>=20 >> # rmmod kvm_intel # modprobe kvm_intel enable_apicv=3DN >> /sys/module/kvm_intel/parameters/enable_apicv:N # >> /usr/bin/qemu-system-x86_64 -machine accel=3Dkvm -name bsdtest -m 51= 2 >> -smp 2,sockets=3D1,cores=3D1,threads=3D2 -drive >> file=3D./20140613_FreeBSD_9.2-RELEASE_ufs.qcow2,if=3Dnone,id=3Ddrive= 0,format=3Dqcow2 >> -device virtio-blk-pci,scsi=3Doff,drive=3Ddrive0 -vnc 0.0.0.0:0 -net >> none >>=20 >> [problem does not occur] >>=20 >> Thank you. This both narrows the problem considerably and provides >> an acceptable workaround. It would still be nice to see it fixed, of >> course. Keep me CC'ed as I'm not on the KVM list. > > I=E2=80=99m resurrecting an old thread since I haven=E2=80=99t heard = anything in a > while. Has anyone looked in to the KVM+apicv bug documented above as > well as here: > > https://bugs.launchpad.net/qemu/+bug/1329956 ? > > If appropriate, where should I go to file a KVM bug (since this isn=E2= =80=99t > really Qemu=E2=80=99s problem)? Hi John, does this happen with the latest upstream kernel version ? Bandan > Thanks, > > JN-- To unsubscribe from this list: send the line "unsubscribe kvm" i= n -- To unsubscribe from this list: send the line "unsubscribe kvm" in