NAK: [SRU][B/C/D] iommu/amd: Reserve and correctly set exclusion range in iova-domain

Kleber Souza kleber.souza at canonical.com
Fri Jun 28 11:24:37 UTC 2019


On 6/24/19 8:21 PM, Jeffrey Lane wrote:
> Hi,
> 
> I wanted to ask if there was anything I could do to help get this
> acked so it makes the next SRU cycle?

Hi Jeff,

I see two threads sent to the mailing-list, with the other one already ACK'ed
and applied for the next SRU cycle:

https://lists.ubuntu.com/archives/kernel-team/2019-June/101705.html

Based on that I'm NAK'ing this particular thread only because it's duplicated,
but the fixes are still committed.


Thanks,
Kleber


> 
> Thanks
> Jeff
> 
> On Mon, Jun 17, 2019 at 9:52 AM Jeffrey Lane <jeffrey.lane at canonical.com> wrote:
>>
>> Hi,
>>
>> Could I get a second ack on these (connork acked it earlier)?
>> I was hoping this could make this cycle, if at all possible.
>>
>> Thanks
>> Jeff
>>
>> On Fri, Jun 7, 2019 at 1:34 PM Jeff Lane <jeffrey.lane at canonical.com> wrote:
>>>
>>> BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1823037
>>>
>>> [Impact]
>>> If a device has an exclusion range specified in the IVRS table, this region
>>> needs to be reserved in the iova-domain of that device. This hasn't happened
>>> until now and can cause data corruption on data transfered with these devices.
>>>
>>> The exlcusion range limit register needs to contain the base-address of the
>>> last page that is part of the range, as bits 0-11 of this register are treated
>>> as 0xfff by the hardware for comparisons.
>>>
>>> So correctly set the exclusion range in the hardware to the last page which is
>>> _in_ the range.
>>>
>>> [Testing]
>>> This was tested by Dell for 24+ hours with positive test results. Testing
>>> involved creating multiple directories with a million files each and then
>>> another script was used across 3-5 threads copying files from one location
>>> to another.  Prior to using test kernels with these patches applied, the system
>>> would fail within 1 - 2 hours consistently.
>>>
>>> [Regression Risk]
>>> Low,this adds memory protection to the driver and has already been applied
>>> upstream and patched test kernels for all three releases have been tested by
>>> Dell for 24 hours with no failures noted.
>>>
>>> Patches cleanly apply to Bionic, Cosmic and Disco. Bionic and Cosmic require
>>> both patches, but Disco only requires the second patch (Set exclusion rage
>>> correctly) as the first patch was already picked up in a previous SRU
>>> (LP: #1830934)
>>>
>>>
>>>
>>
>>
>> --
>> Jeff Lane
>> Technical Partnership and Server Certification Programmes
>>
>> "Entropy isn't what it used to be."
> 
> 
> 




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