[PATCH v3 0/2] Avoid using Xen DMA ops when the device is protected by an IOMMU

Sergiy Kibrik posted 2 patches 2 years, 2 months ago
Failed in applying to current master (apply log)
Documentation/devicetree/bindings/arm/xen.txt | 26 +++++++++++++++++++
arch/arm/mm/dma-mapping.c                     |  2 +-
arch/arm/xen/enlighten.c                      |  9 +++++++
arch/arm64/mm/dma-mapping.c                   |  2 +-
include/xen/swiotlb-xen.h                     |  1 +
5 files changed, 38 insertions(+), 2 deletions(-)
[PATCH v3 0/2] Avoid using Xen DMA ops when the device is protected by an IOMMU
Posted by Sergiy Kibrik 2 years, 2 months ago
At the moment, dom0 can't distinguish which devices are protected by
IOMMU and which are not. In some cases, this can cause swiotlb bounce
buffer use for DMA addresses above 32 bits, which in turn can lead
to poor performance.

Previous discussions at [1,2] agreed upon passing info about IOMMU via
device tree. This series does that in a way consistent with existing iommu bindings.

[1] https://lore.kernel.org/all/1392913234-25429-1-git-send-email-julien.grall__16109.9684810781$1392913341$gmane$org@linaro.org/
[2] https://lore.kernel.org/all/cover.1633106362.git.roman_skakun@epam.com/

Sergiy Kibrik (2):
  dt-bindings: arm: xen: document Xen iommu device
  arm/xen: don't use xen DMA ops when the device is protected by an
    IOMMU

 Documentation/devicetree/bindings/arm/xen.txt | 26 +++++++++++++++++++
 arch/arm/mm/dma-mapping.c                     |  2 +-
 arch/arm/xen/enlighten.c                      |  9 +++++++
 arch/arm64/mm/dma-mapping.c                   |  2 +-
 include/xen/swiotlb-xen.h                     |  1 +
 5 files changed, 38 insertions(+), 2 deletions(-)

Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Julien Grall <julien@xen.org>
Cc: Oleksandr Tyshchenko <olekstysh@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org

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