Hi Steven, On Mon, Jul 11, 2022 at 3:16 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > If you haven't noticed I have patches that are a workaround that fixes this > issue if the conditions are "right". (I Cc'd you) [1] I was on vacation and just combing through the mails :-). I shall have a look at the patch soon.. > > The work around is to not depend on the number in debugfs/kvm/vcpuX to > match the CPU of the guest, but instead to match the ordering of the CPUs > of the guest. It also requires that the guest's CPUs are consecutive and > non sparse. That is, if you have vcpu0, vcpu1, vcpu8 and vcpu9 on the > host, then the guest needs to have CPU 0-3 with the mapping of: > > vcpu0 -> CPU 0 > vcpu1 -> CPU 1 > vcpu8 -> CPU 2 > vcpu9 -> CPU 3 > > and then it works. Of course if this is not true, then it breaks again and > will require some more communication between the host and the guest. This makes sense. I vaguely remember seeing non-increasing patterns in some server machines, but that's really rare I guess. When the debugfs changes for exposing pid are widely available, we can have that also as an option. Thanks for the patches. I shall have a look at the patches soon. ~Vineeth
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