On my system, error message:
[4.322008] dmar: DRHD: handling fault status reg 2
[4.327484] dmar: DMAR:[DMA Read] Request device [21:00.0] fault addr
fff66000
[4.327484] DMAR:[fault reason 01] Present bit in root entry is clear
fault happens on device : 21:00.0
To describe this
On Mon, Aug 18, 2014 at 11:27:01PM +, Li, Zhen-Hua wrote:
: [fault reason 01] Present bit in root entry is clear
It appears when iommu initializing in the kdump kernel.
Hmm, do you have an explanation how this can happen? From how I read the
code, the kdump kernel disables translation on
There is a bug when Linux running on an HP large system:
when kdump kernel runs, the hardware is still using the old
root entry. This causes error message when iommu not finished initialization.
-Original Message-
From: Li, Zhen-Hua
Sent: Monday, August 18, 2014 4:59 PM
To:
On Mon, Aug 18, 2014 at 11:01:56PM +, Li, Zhen-Hua wrote:
There is a bug when Linux running on an HP large system:
when kdump kernel runs, the hardware is still using the old
root entry. This causes error message when iommu not finished initialization.
What error message are you
;
linux-ker...@vger.kernel.org
Subject: Re: [PATCH 1/1] iommu/vt-d : clear old root entry for dump kernel
On Mon, Aug 18, 2014 at 11:01:56PM +, Li, Zhen-Hua wrote:
There is a bug when Linux running on an HP large system:
when kdump kernel runs, the hardware is still using the old
root
-
From: Li, Zhen-Hua
Sent: Tuesday, August 19, 2014 7:27 AM
To: 'Joerg Roedel'
Cc: David Woodhouse; iommu@lists.linux-foundation.org;
linux-ker...@vger.kernel.org
Subject: RE: [PATCH 1/1] iommu/vt-d : clear old root entry for dump kernel
: [fault reason 01] Present bit in root entry is clear
.
-Original Message-
From: Li, Zhen-Hua
Sent: Tuesday, August 19, 2014 7:48 AM
To: Li, Zhen-Hua; Joerg Roedel
Cc: David Woodhouse; iommu@lists.linux-foundation.org;
linux-ker...@vger.kernel.org
Subject: RE: [PATCH 1/1] iommu/vt-d : clear old root entry for dump kernel
When the dump kernel boots
: David Woodhouse; iommu@lists.linux-foundation.org;
linux-ker...@vger.kernel.org
Subject: RE: [PATCH 1/1] iommu/vt-d : clear old root entry for dump kernel
When the dump kernel boots, it will initialize iommu again, and the root entry
will be allocted
in another memory region.
That means, no matter