On Jun 17, 2014, at 10:48 AM, John Nielsen <[email protected]> wrote:
> On Jun 17, 2014, at 12:05 AM, Gleb Natapov <[email protected]> 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 <[email protected]> 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
