On Jun 22, 2015, at 3:48 PM, Bandan Das <bsd@xxxxxxxxxx> wrote: > John Nielsen <lists@xxxxxxxxxxxx> writes: > >> On Jun 17, 2014, at 10:48 AM, John Nielsen <lists@xxxxxxxxxxxx> wrote: >> >>> On Jun 17, 2014, at 12:05 AM, Gleb Natapov <gleb@xxxxxxxxxx> wrote: >>> >>>> 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 <pbonzini@xxxxxxxxxx> >>>>>> wrote: >>>>>> >>>>>>> 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: >>>>> >>>>>> 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 >>>>>> >>>>>> 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! >>> >>>> Does disabling apicv on E5-2650 v2 make reboot problem go away? >>> Yes it does! >>> >>> # modprobe kvm_intel /sys/module/kvm_intel/parameters/enable_apicv:Y >>> # /usr/bin/qemu-system-x86_64 -machine accel=kvm -name bsdtest -m >>> 512 -smp 2,sockets=1,cores=1,threads=2 -drive >>> file=./20140613_FreeBSD_9.2-RELEASE_ufs.qcow2,if=none,id=drive0,format=qcow2 >>> -device virtio-blk-pci,scsi=off,drive=drive0 -vnc 0.0.0.0:0 -net >>> none >>> >>> [problem occurs] >>> >>> # rmmod kvm_intel # modprobe kvm_intel enable_apicv=N >>> /sys/module/kvm_intel/parameters/enable_apicv:N # >>> /usr/bin/qemu-system-x86_64 -machine accel=kvm -name bsdtest -m 512 >>> -smp 2,sockets=1,cores=1,threads=2 -drive >>> file=./20140613_FreeBSD_9.2-RELEASE_ufs.qcow2,if=none,id=drive0,format=qcow2 >>> -device virtio-blk-pci,scsi=off,drive=drive0 -vnc 0.0.0.0:0 -net >>> none >>> >>> [problem does not occur] >>> >>> 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’m resurrecting an old thread since I haven’t 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’t >> really Qemu’s problem)? > > Hi John, does this happen with the latest upstream kernel version ? I know for sure it happens with 4.0.4 and I’m not aware of any newer changes that would affect it.-- To unsubscribe from this list: send the line "unsubscribe kvm" in
