Re: IVDB DTE_ALL Settings

[Valentine Sinitsyn <valentine.sinitsyn-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Hi Joerg,

On 04.08.2015 21:56, Joerg Roedel wrote:
> Hi David,
>
> On Tue, Aug 04, 2015 at 05:57:45AM +0300, David Kiarie wrote:
>> Basically, the iommu->last/first_device fields are initialized in
>> another state of the driver much later in the code(during PCI
>> initialization); the values iommu->first/last_device are used before
>> initialization which breaks the logic of this code.
>
> You are right, this is probably broken for some time, on the other side
> it doesn't matter for now as I've never seen an IVRS table with an
> IVHD_ALL field. I'll do a patch to fix this, thanks for the report.
Not directly related to the issue David discovered, but as we discuss 
IVRS handling: the specification says that ACPI tables data overrides 
what's in hardware registers (Sect. 5). To the best of my understanding, 
this means e.g. I should take HATS value not from EFR but from IVHD Type 
10 block. However, amd_iommu driver code checks for features directly - 
for what reason? I'm not suggesting this is a bug, but rather asking 
your opinion here.

Thanks,
Valentine