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)? Thanks, JN-- To unsubscribe from this list: send the line "unsubscribe kvm" in
