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Date:   Mon, 26 Jul 2021 14:25:39 +0200
From:   Joerg Roedel <joro@8bytes.org>
To:     Kyung Min Park <kyung.min.park@intel.com>
Cc:     iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
        baolu.lu@linux.intel.com, dwmw2@infradead.org, will@kernel.org,
        yian.chen@intel.com, sohil.mehta@intel.com,
        ravi.v.shankar@intel.com, ashok.raj@intel.com
Subject: Re: [PATCH v2] iommu/vt-d: Dump DMAR translation structure
Message-ID: <YP6pw9j8i3bGOb13@8bytes.org>
References: <20210722042453.10579-1-kyung.min.park@intel.com>
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On Wed, Jul 21, 2021 at 09:24:53PM -0700, Kyung Min Park wrote:
> When the dmar translation fault happens, the kernel prints a single line
> fault reason with corresponding hexadecimal code defined in the Intel VT-d
> specification.
> 
> Currently, when user wants to debug the translation fault in detail,
> debugfs is used for dumping the dmar_translation_struct, which is not
> available when the kernel failed to boot.
> 
> Dump the DMAR translation structure, pagewalk the IO page table and print
> the page table entry when the fault happens.
> 
> Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>

This is too much noise in dmesg for a single dmar fault. Please hide
that additional debug information behind a debug kernel option for the
VT-d driver.

Thanks,
	
	Joerg