linux-kernel - Re: [PATCH kernel] powerpc/powernv/ioda2: Add devices only from buses which belong to PE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat, 13 Jun 2015 02:47:56 +1000
From:	Alexey Kardashevskiy <aik@...abs.ru>
To:	Nishanth Aravamudan <nacc@...ux.vnet.ibm.com>,
	Gavin Shan <gwshan@...ux.vnet.ibm.com>
CC:	linux-kernel@...r.kernel.org, Paul Mackerras <paulus@...ba.org>,
	linuxppc-dev@...ts.ozlabs.org,
	David Gibson <david@...son.dropbear.id.au>
Subject: Re: [PATCH kernel] powerpc/powernv/ioda2: Add devices only from buses
 which belong to PE

On 06/13/2015 01:06 AM, Nishanth Aravamudan wrote:
> On 12.06.2015 [16:47:03 +1000], Gavin Shan wrote:
>> On Fri, Jun 12, 2015 at 04:19:17PM +1000, Alexey Kardashevskiy wrote:
>>> The existing code puts all devices from a root PE to the same IOMMU group.
>>> However it is a possible situation when subordinate buses belong to
>>> separate PEs, in this case devices from these subordinate buses
>>> should be added to lower level PE rather to the root PE.
>>>
>>> This limits pnv_ioda_setup_bus_dma() invocation to only PEs which own
>>> all subordinate buses.
>>>
>>> Suggested-by: Gavin Shan <gwshan@...ux.vnet.ibm.com>
>>> Signed-off-by: Alexey Kardashevskiy <aik@...abs.ru>
>>
>> Alexey, I think it's good candidate for stable.
>
> Why? This commit message doesn't imply there is a serious bug just a
> "possible" (does that mean theoretical?) situtation and the following:
>
>>> This would be nice to have together with the DDW patchset.
>>> This does not fix anything DDW patchset did, it fixes IOMMU
>>> groups management which is essential for the whole feature to work.
>
> implies it is both related and independent of DDW?


DDW is for fast devices and I just got my hands on a "firestone" machine 
(p8 + nvidia tesla = very fast machine) where this bug appeared first time.


-- 
Alexey
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/