Re: [RFC PATCH 3/3] kvm: arm/arm64: vgic-its: fix return value for restore

[wanghaibin <wanghaibin.wang@huawei.com>]

On 2017/9/14 16:30, Auger Eric wrote:

> Hi Wanghaibin,
> 
> On 06/09/2017 15:05, wanghaibin wrote:
>> This patch fix the migrate restore tables failure.
>>
>> The same scene, at the destination, the restore tables interface traversal guest
>> memory, and check the dte/ite is valid or not.
>> If all dtes/ites are invalid, we will do try next one, and the last it will take
>> the 1 return value, but currently, it be treated as error. That's not correct.
>>
>> This patch try to fix this problem.
>>
>> Signed-off-by: wanghaibin <wanghaibin.wang@huawei.com>
>> ---
>>  virt/kvm/arm/vgic/vgic-its.c | 5 +----
>>  1 file changed, 1 insertion(+), 4 deletions(-)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> index 5c20352..2c69aeb 100644
>> --- a/virt/kvm/arm/vgic/vgic-its.c
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -2025,7 +2025,7 @@ static int vgic_its_restore_dte(struct vgic_its *its, u32 id,
>>  		return PTR_ERR(dev);
>>  
>>  	ret = vgic_its_restore_itt(its, dev);
>> -	if (ret) {
>> +	if (ret < 0) {
>>  		vgic_its_free_device(its->dev->kvm, dev);
>>  		return ret;
>>  	}
>> @@ -2147,9 +2147,6 @@ static int vgic_its_restore_device_tables(struct vgic_its *its)
>>  				     vgic_its_restore_dte, NULL);
>>  	}
>>  
>> -	if (ret > 0)
>> -		ret = -EINVAL;
> Reworking error handling in scan_its_table as I previously proposed
> indeed don't work for L2 tables, as pointed out by Christoffer. As such
> I eventually think your approach is the best.
> 
> The only remark I have left is restore table IOCTL is likely to return 1
> with your change. 1 is not documented in the API as a returned value. I
> think we should return 0 in this case. We are lucky because QEMU
> kvm_device_access does not interpret positive values as errors.


Will fix it.
Thanks.

> 
> Thanks
> 
> Eric
> 
>> -
>>  	return ret;
>>  }
>>  
>>
> 
> .
>