lkml.org 
[lkml]   [2018]   [Jan]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 04/12] pci-p2p: Clear ACS P2P flags for all client devices


On 04/01/18 05:00 PM, Logan Gunthorpe wrote:
>
>
> On 04/01/18 03:35 PM, Alex Williamson wrote:
>> Yep, flipping these ACS bits invalidates any IOMMU groups that depend
>> on the isolation of that downstream port and I suspect also any peers
>> within the same PCI slot of that port and their downstream devices.  The
>> entire sub-hierarchy grouping needs to be re-evaluated.  This
>> potentially affects running devices that depend on that isolation, so
>> I'm not sure how that happens dynamically.  A boot option might be
>> easier.  Thanks,
>

Also, considering this further: if you can point me to a way to tell if
a device is in an IOMMU group it should be pretty easy to disallow a
device that has been assigned to a group from being used in P2P
transactions.

Logan

\
 
 \ /
  Last update: 2018-01-05 02:11    [W:3.189 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site