lkml.org 
[lkml]   [2011]   [Nov]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH retry] intel-iommu:make identity_map default for crash dump
On 11/01/2011 05:34 PM, David Woodhouse wrote:

> On Tue, 2011-11-01 at 17:19 +0800, Dave Young wrote:
>> kdump kernel sometimes will get DMAR faults which
>> is caused by random in-flight dma from 1st kernel
>>
>> Here make the identity_mapping as default for this case
>
> So you want to *allow* the random in-flight DMA? And with an identity
> mapping it's really going to random addresses, since it'll be
> untranslated and won't even go to the physical addresses which it was
> originally intended for?
>
> This seems entirely broken to me.
>
> If there is "random in-flight dma" from the first kernel, the correct
> thing to do is *block* it. Which is what we do.
>


This patch works for me for several cases. For kdump It can be seen a
workaround. But yes blocking the 1st kernel dma is ideal.

Glad to hear that you are working on this.

--
Thanks
Dave


\
 
 \ /
  Last update: 2011-11-01 10:53    [W:0.028 / U:0.020 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site