Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock

From: Wanpeng Li
Date: Tue Jan 03 2017 - 17:04:16 EST


2017-01-04 1:23 GMT+08:00 Paolo Bonzini <pbonzini@xxxxxxxxxx>:
>
>
> On 03/01/2017 13:06, David Hildenbrand wrote:
>>>
>>> switch (cap->cap) {
>>> case KVM_CAP_HYPERV_SYNIC:
>>> - return kvm_hv_activate_synic(vcpu);
>>> + if (!irqchip_in_kernel(vcpu->kvm))
>>> + return -EINVAL;
>>> + else
>>
>> You can simply drop the else and return directly.
>>
>> Can't really say if this is the right fix, my first thought was that
>> a request has been set although it should never have been set for
>> that VCPU. Maybe that is an effect of synic being activated
>> (because synic code unconditionally later on sets the request).
>>
>> Fixing the cause of the request seems better than fixing up the result.
>
> Yes, I agree. Wanpeng's second patch is fine.

Thanks Paolo, I will send out a formal one soon.

Regards,
Wanpeng Li