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From: Baolu Lu <baolu.lu@linux.intel.com>
To: Chathura Rajapaksha <chathura.abeyrathne.lk@gmail.com>,
	iommu@lists.linux.dev
Cc: baolu.lu@linux.intel.com
Subject: Re: Software bounce buffers Vs allocating DMA buffers in page granularity
Date: Fri, 18 Aug 2023 09:23:32 +0800	[thread overview]
Message-ID: <fdc6b5fc-0e26-965d-ae53-fd4a0f87d1ea@linux.intel.com> (raw)
In-Reply-To: <CAD7mqrygN8W59SmeS2nEVppNVeoW3FsiVtOG_PH7fcV4C16YEg@mail.gmail.com>

On 2023/8/18 4:17, Chathura Rajapaksha wrote:
> Hi All,
> 
> I have a question regarding the IOMMU software bounce buffer feature.
> I understand that this feature was introduced as a mitigation to
> sub-page vulnerabilities (which were shown to be exploitable by
> Thunderclap).
> 
> My question is:
> Can allocating DMA buffers in page granularity (multiples of 4KB pages)
> be a feasible alternative solution to software bounce buffers?

Yes. I remember that we skip software bounce buffer if the buffer size
is one or multiple PAGE_SIZE(s). Any change during recent evolution?

Best regards,
baolu

  reply	other threads:[~2023-08-18  1:23 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-17 20:17 Software bounce buffers Vs allocating DMA buffers in page granularity Chathura Rajapaksha
2023-08-18  1:23 ` Baolu Lu [this message]
2023-08-18 15:08 ` Robin Murphy

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