Re: [PATCH 1/1] KVM: x86: to track if L1 is running L2 VM

From: Dongli Zhang
Date: Fri Mar 12 2021 - 14:42:17 EST


Hi Paolo,

On 3/6/21 5:56 AM, Paolo Bonzini wrote:
> On 05/03/21 23:57, Dongli Zhang wrote:
>> The new per-cpu stat 'nested_run' is introduced in order to track if L1 VM
>> is running or used to run L2 VM.
>>
>> An example of the usage of 'nested_run' is to help the host administrator
>> to easily track if any L1 VM is used to run L2 VM. Suppose there is issue
>> that may happen with nested virtualization, the administrator will be able
>> to easily narrow down and confirm if the issue is due to nested
>> virtualization via 'nested_run'. For example, whether the fix like
>> commit 88dddc11a8d6 ("KVM: nVMX: do not use dangling shadow VMCS after
>> guest reset") is required.
>>
>> Cc: Joe Jin <joe.jin@xxxxxxxxxx>
>> Signed-off-by: Dongli Zhang <dongli.zhang@xxxxxxxxxx>
...
>
> Queued, thanks.
>
> Paolo
>

While testing the most recent kvm tree, I did not find this patch queued
(debugfs entry for nested_run not available). Would you mind help confirm?

Thank you very much!

Dongli Zhang