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

[Paolo Bonzini]

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.

Paolo