archive mirror
 help / color / mirror / Atom feed
From: Joerg Roedel <>
To: Deepa Dinamani <>
Subject: Re: [PATCH v2] iommu/vt-d: Turn off translations at shutdown
Date: Mon, 11 Nov 2019 16:08:15 +0100	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On Sun, Nov 10, 2019 at 09:27:44AM -0800, Deepa Dinamani wrote:
> The intel-iommu driver assumes that the iommu state is
> cleaned up at the start of the new kernel.
> But, when we try to kexec boot something other than the
> Linux kernel, the cleanup cannot be relied upon.
> Hence, cleanup before we go down for reboot.
> Keeping the cleanup at initialization also, in case BIOS
> leaves the IOMMU enabled.
> I considered turning off iommu only during kexec reboot, but a clean
> shutdown seems always a good idea. But if someone wants to make it
> conditional, such as VMM live update, we can do that.  There doesn't
> seem to be such a condition at this time.
> Tested that before, the info message
> 'DMAR: Translation was enabled for <iommu> but we are not in kdump mode'
> would be reported for each iommu. The message will not appear when the
> DMA-remapping is not enabled on entry to the kernel.
> Signed-off-by: Deepa Dinamani <>
> ---
> Changes since v1:
> * move shutdown registration to iommu detection
>  drivers/iommu/dmar.c        |  5 ++++-
>  drivers/iommu/intel-iommu.c | 20 ++++++++++++++++++++
>  include/linux/dmar.h        |  2 ++
>  3 files changed, 26 insertions(+), 1 deletion(-)

Applied, thanks.

      parent reply	other threads:[~2019-11-11 15:08 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-10 17:27 [PATCH v2] iommu/vt-d: Turn off translations at shutdown Deepa Dinamani
2019-11-11  1:32 ` Lu Baolu
2019-11-11  3:21   ` Deepa Dinamani
2019-11-11  4:58     ` Lu Baolu
2019-11-11  5:00 ` Lu Baolu
2019-11-11 15:08 ` Joerg Roedel [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).