On 08/27/2014 05:31 PM, Zhang Haoyu wrote: >>>>>>> Hi, all >>>>>>> >>>>>> >>>>>>> >>>>>> I use a qemu-1.4.1/qemu-2.0.0 to run win7 guest, and encounter e1000 NIC interrupt storm, >>>>>>> >>>>>> because "if (!ent->fields.mask && (ioapic->irr & (1 << i)))" is always true in __kvm_ioapic_update_eoi(). >>>>>>> >>>>>> >>>>>>> >>>>>> Any ideas? >>>>>> >>>>> We meet this several times: search the autoneg patches for an example of >>>>>> >>>>> workaround for this in qemu, and patch kvm: ioapic: conditionally delay >>>>>> >>>>> irq delivery during eoi broadcast for an workaround in kvm (rejected). >>>>>> >>>>> >>>>> >>>> Thanks, Jason, >>>>> >>>> I searched "e1000 autoneg" in gmane.comp.emulators.qemu, and found below patches, >>>>> >>>> http://thread.gmane.org/gmane.comp.emulators.qemu/143001/focus=143007 >>>> >>> This series is the first try to fix the guest hang during guest >>>> >>> hibernation or driver enable/disable. >>>>> >>>> http://thread.gmane.org/gmane.comp.emulators.qemu/284105/focus=284765 >>>>> >>>> http://thread.gmane.org/gmane.comp.emulators.qemu/186159/focus=187351 >>>> >>> Those are follow-up that tries to fix the bugs introduced by the autoneg >>>> >>> hack. >>>>> >>>> which one tries to fix this problem, or all of them? >>>> >>> As you can see, those kinds of hacking may not as good as we expect >>>> >>> since we don't know exactly how e1000 works. Only the register function >>>> >>> description from Intel's manual may not be sufficient. And you can >>>> >>> search e1000 in the archives and you can find some behaviour of e1000 >>>> >>> registers were not fictionalized like what spec said. It was really >>>> >>> suggested to use virtio-net instead of e1000 in guest. >>> >> Will the "[PATCH] kvm: ioapic: conditionally delay irq delivery during eoi broadcast" add delay to virtual interrupt injection sometimes, >>> >> then some time delay sensitive applications will be impacted? >> > >> >I don't test it too much but it only give a minor delay of 1% irq in the >> >hope of guest irq handler will be registered shortly. But I suspect it's >> >the bug of e1000 who inject the irq in the wrong time. Under what cases >> >did you meet this issue? > Some scenarios, not constant and 100% reproducity, > e.g., reboot vm, ifdown e1000 nic, install kaspersky(network configuration is performed during installing stage), .etc. If you want to start the debugging, I suggest to enable e1000 debug and then analysis the log before the interrupt storm. This may help to locate the issue. Thanks -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
