lkml.org 
[lkml]   [2014]   [Apr]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCHv3 0/6] Crashdump Accepting Active IOMMU
From
Date
On Mon, 2014-04-07 at 16:43 -0400, Don Dutile wrote:
>
> Additionally, a tidbit of information like "some servers force NMI's
> on DMAR faults,
> and cause a system reset, thereby, preventing a kdump to occur"
> should have been included as one reason to stop DMAR faults from
> occurring on kexec-boot,
> in addition to the fact that a flood of them can lock up a system.

How about allocating a physical scratch page, and setting up a mapping
for each device such that *every* virtual address (apart from those
listed in RMRRs, perhaps) is mapped to that same scratch page?

That way you avoid the faults, but you also avoid stray DMA to parts of
the system that you don't want to get corrupted.

--
David Woodhouse Open Source Technology Centre
David.Woodhouse@intel.com Intel Corporation
[unhandled content-type:application/x-pkcs7-signature]
\
 
 \ /
  Last update: 2014-04-08 18:41    [W:0.184 / U:31.068 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site