Messages in this thread | | | Date | Tue, 16 Aug 2022 08:58:41 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH v3 3/4] kernel/smp: add more data to CSD lock debugging |
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On Tue, Aug 16, 2022 at 07:53:49PM +0900, Chang-Ho Cho wrote: > Hello, > > Google search brought me into this thread. May I have update on the progress of this issue? Has anyone find root cause, solution or workaround? > How can I get more about the problem? > Windows 2008 R2 VM experiencing hang on QEMU-kvm with IPI handling issue.
Here is a blog entry describing the bug that was causing me trouble:
https://paulmck.livejournal.com/62071.html
But although this appeared to be an IPI-loss problem, it was in fact an interrupt storm.
Juergen, who you CCed, located a race-condition issue with a non-KVM hypervisor, if I recall correctly.
Of course, much depends on the exact versions of your various OSes and firmware. One useful trick is to look for fixes since whichever version of Linux you are using, and to backport those. Also, for issues with Windows, you are likely better served asking elsewhere. Since you are asking here, I am assuming that you have somehow proven that the interrupt is being lost in KVM or QEMU rather than in the Windows guest.
Please note that observing the hang on QEMU/KVM but not on bare metal is insufficient, given that the difference in timing can dramatically change the probability of bugs occuring.
Thanx, Paul
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