From: Eric Biggers <ebiggers@kernel.org>
To: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Cc: Vinod Koul <vkoul@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
Thara Gopinath <thara.gopinath@gmail.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>,
Udit Tiwari <quic_utiwari@quicinc.com>,
Md Sadre Alam <mdalam@qti.qualcomm.com>,
Dmitry Baryshkov <lumag@kernel.org>,
Manivannan Sadhasivam <mani@kernel.org>,
Stephan Gerhold <stephan.gerhold@linaro.org>,
Bjorn Andersson <andersson@kernel.org>,
Mukesh Kumar Savaliya <mukesh.savaliya@oss.qualcomm.com>,
Peter Ujfalusi <peter.ujfalusi@gmail.com>,
Michal Simek <michal.simek@amd.com>,
Frank Li <Frank.Li@kernel.org>,
Andy Gross <agross@codeaurora.org>,
Neil Armstrong <neil.armstrong@linaro.org>,
Vignesh Raghavendra <vigneshr@ti.com>,
dmaengine@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-crypto@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, brgl@kernel.org,
Bartosz Golaszewski <bartosz.golaszewski@linaro.org>,
Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>,
Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>,
Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Subject: Re: [PATCH v24 00/14] crypto/dmaengine: qce: introduce BAM locking and use DMA for register I/O
Date: Thu, 23 Jul 2026 10:27:28 -0700 [thread overview]
Message-ID: <20260723172728.GA93534@quark> (raw)
In-Reply-To: <20260723-qcom-qce-cmd-descr-v24-0-4f87bb4d9938@oss.qualcomm.com>
On Thu, Jul 23, 2026 at 07:09:06PM +0200, Bartosz Golaszewski wrote:
> Currently the QCE crypto driver accesses the crypto engine registers
> directly via CPU. Trust Zone may perform crypto operations simultaneously
> resulting in a race condition.
You've claimed elsewhere that this isn't actually a problem currently
(since the problem will be introduced by a future TrustZone software
update). If true, shouldn't the cover letter and commit messages be
corrected accordingly?
However, what if someone runs a LTS kernel on a system that has this
TrustZone update? None of these patches have Cc stable, so LTS kernels
won't get them.
Also, won't these changes further exacerbate the performance issues with
this driver? This series adds a lot of additional overhead, for example
by replacing fast MMIO writes with DMA transactions using highly
fragmented scatterlists (see qce_write()). There are also new dynamic
memory allocations, which can fail. In addition, there can now be an
additional delay to wait for TrustZone to stop using the hardware.
> Tested with tcrypt.ko, kcapi and cryptsetup.
Did this include testing that this patch series solves the problem it
claims to -- synchronizing between Linux and TrustZone?
- Eric
prev parent reply other threads:[~2026-07-23 17:27 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-23 17:09 [PATCH v24 00/14] crypto/dmaengine: qce: introduce BAM locking and use DMA for register I/O Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 01/14] dmaengine: constify struct dma_descriptor_metadata_ops Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 02/14] dmaengine: qcom: bam_dma: free interrupt before the clock in error path Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 03/14] dmaengine: qcom: bam_dma: convert tasklet to a BH workqueue Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 04/14] dmaengine: qcom: bam_dma: Extend the driver's device match data Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 05/14] dmaengine: qcom: bam_dma: Add pipe_lock_supported flag support Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 06/14] dmaengine: qcom: bam_dma: add support for BAM locking Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 07/14] crypto: qce - Cancel work on device detach Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 08/14] crypto: qce - Include algapi.h in the core.h header Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 09/14] crypto: qce - Remove unused ignore_buf Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 10/14] crypto: qce - Simplify arguments of devm_qce_dma_request() Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 11/14] crypto: qce - Use existing devres APIs in devm_qce_dma_request() Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 12/14] crypto: qce - Map crypto memory for DMA Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 13/14] crypto: qce - Add BAM DMA support for crypto register I/O Bartosz Golaszewski
2026-07-23 17:09 ` [PATCH v24 14/14] crypto: qce - Communicate the base physical address to the dmaengine Bartosz Golaszewski
2026-07-23 17:27 ` Eric Biggers [this message]
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