Re: [PATCH] virt/kvm/assigned-dev.c: Set 'dev->irq_source_id' to '-1' after free it

[Paolo Bonzini <pbonzini@redhat.com>]

Il 19/08/2014 17:44, Chen Gang ha scritto:
> Hello maintainers:
> 
> Please help check this patch, when you have time.

Hi, it's already on its way to 3.17-rc2, but I first have to run a bunch
of tests.

Paolo

> Thanks.
> 
> On 08/08/2014 11:37 PM, Chen Gang wrote:
>> As a generic function, deassign_guest_irq() assumes it can be called
>> even if assign_guest_irq() is not be called successfully (which can be
>> triggered by ioctl from user mode, indirectly).
>>
>> So for assign_guest_irq() failure process, need set 'dev->irq_source_id'
>> to -1 after free 'dev->irq_source_id', or deassign_guest_irq() may free
>> it again.
>>
>> Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
>> ---
>>  virt/kvm/assigned-dev.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
>> index bf06577..5819a27 100644
>> --- a/virt/kvm/assigned-dev.c
>> +++ b/virt/kvm/assigned-dev.c
>> @@ -526,8 +526,10 @@ static int assign_guest_irq(struct kvm *kvm,
>>  		dev->irq_requested_type |= guest_irq_type;
>>  		if (dev->ack_notifier.gsi != -1)
>>  			kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
>> -	} else
>> +	} else {
>>  		kvm_free_irq_source_id(kvm, dev->irq_source_id);
>> +		dev->irq_source_id = -1;
>> +	}
>>  
>>  	return r;
>>  }
>>