From: Baolu Lu <baolu.lu@linux.intel.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: baolu.lu@linux.intel.com, David Woodhouse <dwmw2@infradead.org>,
iommu@lists.linux.dev
Subject: Re: lack of permission checking with intel-iommu?
Date: Tue, 2 Jul 2024 17:12:32 +0800 [thread overview]
Message-ID: <0d0c9d4b-b233-4ac8-9a46-9da24f1c5536@linux.intel.com> (raw)
In-Reply-To: <ZoO5ZeYtA6qLIs21@infradead.org>
On 2024/7/2 16:25, Christoph Hellwig wrote:
> On Tue, Jul 02, 2024 at 04:22:25PM +0800, Baolu Lu wrote:
>> Is it about IOMMU blocking "device reading from buffer" or "device
>> writing to buffer"?
>>
>> The intel iommu driver might use first-stage translation for kernel DMA.
>> It seems not to block the "device reading from buffer" if I remember it
>> correctly.
> This is about device reading from buffer it is only supposed to write
> to (but doesn't).
In this case, Intel IOMMU doesn't block device reading as the first-
stage page table only grants two types of permissions: Read-only or
Read-write. Write-only permission is not available.
Do you have a functional requirement for Write-only permission? If so,
we can choose the second-stage page table.
Best regards,
baolu
next prev parent reply other threads:[~2024-07-02 9:12 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-02 7:46 lack of permission checking with intel-iommu? Christoph Hellwig
2024-07-02 8:02 ` Christoph Hellwig
2024-07-02 8:22 ` Baolu Lu
2024-07-02 8:25 ` Christoph Hellwig
2024-07-02 9:12 ` Baolu Lu [this message]
2024-07-02 11:42 ` Christoph Hellwig
2024-07-03 0:56 ` Tian, Kevin
2024-07-03 2:28 ` Baolu Lu
2024-07-02 8:47 ` Yi Liu
2024-07-02 9:07 ` Baolu Lu
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