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SubjectRe: [PATCH 0/3] iommu/vt-d bad RMRR workarounds
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On 12/13/2019 5:52 PM, Lu Baolu wrote:
>
> On 12/13/19 10:31 PM, Barret Rhoden wrote:
>> On 12/11/19 9:43 PM, Lu Baolu wrote:
>>> The VT-d spec defines the BIOS considerations about RMRR in section
>>> 8.4:
>>>
>>> "
>>> BIOS must report the RMRR reported memory addresses as reserved (or as
>>> EFI runtime) in the system memory map returned through methods such as
>>> INT15, EFI GetMemoryMap etc.
>>> "
>>>
>>> So we should treat it as firmware bug if the RMRR range is not
>>> mapped as
>>> RESERVED in the system memory map table.
>>>
>>> As for how should the driver handle this case, ignoring buggy RMRR with
>>> a warning message might be a possible choice.
>>
>> Agreed, firmware should not be doing this.  My first patch just skips
>> those entries, instead of aborting DMAR processing, and keeps the
>> warning.
>>
>
> Hi Yian,
>
> Does this work for you?
>
> Best regards,
> baolu
>
>
I made a comment in the the patch email "[PATCH 1/3] iommu/vt-d: skip
RMRR entries that fail the sanity check "
thanks,
Yian

>> So long as the machine still boots in a safe manner, I'm reasonably
>> happy.
>>
>> Thanks,
>>
>> Barret
>>
>>

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