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From: Lu Baolu <baolu.lu@linux.intel.com>
To: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: baolu.lu@linux.intel.com,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	joro@8bytes.org, David Woodhouse <dwmw2@infradead.org>,
	iommu@lists.linux-foundation.org
Subject: Re: [PATCH v2] iommu/vt-d: Turn off translations at shutdown
Date: Mon, 11 Nov 2019 12:58:28 +0800	[thread overview]
Message-ID: <155325c9-5c7b-9fb1-edaf-2c22d67f207c@linux.intel.com> (raw)
In-Reply-To: <CABeXuvofh-z97=iq9S7E1igbzyWwNU-MPbuCjNa_gzC3Q=L7hg@mail.gmail.com>

Hi,

On 11/11/19 11:21 AM, Deepa Dinamani wrote:
> 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.

Okay, thanks for the explanation.

> 
> -Deepa
> 

Best regards,
baolu

  reply	other threads:[~2019-11-11  5:02 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 [this message]
2019-11-11  5:00 ` Lu Baolu
2019-11-11 15:08 ` Joerg Roedel

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