Re: [PATCH 1/1] iommu/vt-d: Fix agaw for a supported 48 bit guest address width

[Lu Baolu <baolu.lu@linux.intel.com>]

On 2021/8/16 20:37, Greg Kroah-Hartman wrote:
> On Mon, Aug 16, 2021 at 08:20:31PM +0800, Lu Baolu wrote:
>> Hi Greg,
>>
>> On 2021/8/16 19:48, Greg Kroah-Hartman wrote:
>>> On Mon, Aug 16, 2021 at 07:39:32PM +0800, Lu Baolu wrote:
>>>> From: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
>>>>
>>>> [ Upstream commit 327d5b2fee91c404a3956c324193892cf2cc9528 ]
>>>
>>> Also, this really does not look like this commit at all :(
>>>
>>
>> This is not a back port. It's a fix for some stable kernels. Sorry for
>> the confusion.
>>
>> The error happens in a helper function that has been deprecated in the
>> upstream kernel by above commit. I added below explanation in the commit
>> message:
>>
>> "
>> This issue happens on the code path of getting a private domain for a
>> device. A private domain was needed when the domain of an iommu group
>> couldn't meet the requirement of a device. The IOMMU core has been
>> evolved to eliminate the need for private domain, hence this code path
>> has already been removed from the upstream since commit 327d5b2fee91c
>> ("iommu/vt-d: Allow 32bit devices to uses DMA domain"). Instead of back
>> porting all patches that are required for removing the private domain,
>> this simply fixes it in the affected stable kernel between v4.16 and v5.7.
>> "
>>
>> I'm sorry if this is not the right way to do this.
> 
> Ah, sorry, I totally missed that.  This is fine, now queued up for
> 4.19.y and 5.4.y.

Thank you! Greg.

Best regards,
baolu

> 
> thanks,
> 
> greg k-h
>