[lkml]   [2018]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] iommu/amd - Use dev_err to send events to the system log
On Tue, Feb 13, 2018 at 02:24:56PM -0500, Hook, Gary wrote:
> Without actually running a driver and getting some debug info, I'll just
> say that my example compiled, the amd_iommu structure points to a pci_dev
> which contains a device, and the two possibilities are likely equivalent.
> I'll vet that, of course, but working under the assumption that they are
> equivalent, the question becomes, do you have a preference?

They are not equivalent, your version points to the pci_dev containing
the IOMMU, my version points to the (virtual) iommu-device for that
particular iommu in the kernel.

So the difference in the prefix is:

your version: '0000:00:00.2:'

vs. my version: 'ivhd0:'

The latter is the better prefix, because it points to the iommu. A
pci_dev can contain more than one iommu, so that prefix is not specific
enough. I know that there is currently no hardware implementing multiple
iommus on one pci_dev, but it is allowed according to the spec.



 \ /
  Last update: 2018-02-14 12:50    [W:0.111 / U:0.960 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site