Re: [PATCH] KVM: x86: Kick VCPU outside PIC lock again

Jan Kiszka
2010-02-24T10:28:44Z

Jan Kiszka wrote:
> Avi Kivity wrote:
>> On 02/24/2010 12:13 PM, Jan Kiszka wrote:
>>>
>>>> I see. Won't we hit the same issue when we call pic functions from
>>>> atomic context during the guest entry sequence?
>>>>
>>>>
>>> If there are such call paths, for sure. What concrete path(s) do you
>>> have in mind?
>>>
>>>
>> vcpu_enter_guest() -> inject_pending_event() ->
>> kvm_cpu_{has,get}_interrupt() -> various pic functions if you're unlucky.
>
> But do they kick anyone or just check/pull information? Never saw any
> warnings during my tests last year (granted: with older -rt and kvm
> versions).

Mmh, they could if there is > 1 IRQ pending. Guess this just never
triggered in real life due to typical APIC use and low IRQ load during
PIC times in my tests.

Jan

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