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From:   Zhenzhong Duan <zhenzhong.duan@gmail.com>
Date:   Wed, 11 Nov 2020 08:24:52 +0800
Message-ID: <CAFH1YnMb0MB+-hg7KWEzpGc_bUAv0UhR4_zBn4Sh8T3zjDMKuw@mail.gmail.com>
Subject: Re: [PATCH v2] iommu/vt-d: avoid unnecessory panic if iommu init fail
 in tboot system
To:     Lukasz Hawrylko <lukasz.hawrylko@linux.intel.com>
Cc:     linux-kernel <linux-kernel@vger.kernel.org>, ning.sun@intel.com,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, David Woodhouse <dwmw2@infradead.org>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        Joerg Roedel <joro@8bytes.org>,
        iommu@lists.linux-foundation.org, tboot-devel@lists.sourceforge.net
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Hi Lukasz,

On Tue, Nov 10, 2020 at 11:53 PM Lukasz Hawrylko
<lukasz.hawrylko@linux.intel.com> wrote:
>
> Hi Zhenzhong
>
> On Tue, 2020-11-10 at 15:19 +0800, Zhenzhong Duan wrote:
> > "intel_iommu=off" command line is used to disable iommu but iommu is force
> > enabled in a tboot system for security reason.
> >
> > However for better performance on high speed network device, a new option
> > "intel_iommu=tboot_noforce" is introduced to disable the force on.
> >
> > By default kernel should panic if iommu init fail in tboot for security
> > reason, but it's unnecessory if we use "intel_iommu=tboot_noforce,off".
> >
> > Fix the code setting force_on and move intel_iommu_tboot_noforce
> > from tboot code to intel iommu code.
> >
> > Fixes: 7304e8f28bb2 ("iommu/vt-d: Correctly disable Intel IOMMU force on")
> > Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
> > ---
> > v2: move ckeck of intel_iommu_tboot_noforce into iommu code per Baolu.
>
> I have check it on my TXT testing environment with latest TBOOT,
> everything works as expected.

Thanks very much for help checking, may I have your Tested-by?

Zhenzhong