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From: Deepa Dinamani <deepa.kernel@gmail.com>
To: Lu Baolu <baolu.lu@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	iommu@lists.linux-foundation.org
Subject: Re: [PATCH v2] iommu/vt-d: Turn off translations at shutdown
Date: Sun, 10 Nov 2019 19:21:45 -0800
Message-ID: <CABeXuvofh-z97=iq9S7E1igbzyWwNU-MPbuCjNa_gzC3Q=L7hg@mail.gmail.com> (raw)
In-Reply-To: <9e2e95e2-37ac-c0d6-d438-bd09ba7064bd@linux.intel.com>

On Sun, Nov 10, 2019 at 5:35 PM Lu Baolu <baolu.lu@linux.intel.com> wrote:
>
> Hi,
>
> On 11/11/19 1:27 AM, 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.
>
> Do you mind shining more light on this statement? I can't get your point
> here. Currently iommu_shutdown() only happens for reboot, right?

In this part, I'm saying that I'm leaving intel_iommu_init() alone.
I'm not taking out disabling the iommu from intel_iommu_init(). This
will help when BIOS has enabled the IOMMU and for whatever reason, the
kernel is booting with IOMMU off.

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

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