numam-spdk/doc/system_configuration.md
tone.zhang bf6a6019b2 Doc: Clarify the IOMMU configuration for User Space Drivers
In the case system charges PCI devices with the "uio_pci_generic"
kernel driver, the IOMMU should be disabled or passthrough, because
the virtual / physical address conversion by IOMMU will make the DMA
transmission invalid.

The patch guides users configure IOMMU in SPDK target system on both
x86_64 and arm64 systems.

Change-Id: I66df4df855a6669d4838eb88bd400ded87d08a49
Signed-off-by: tone.zhang <tone.zhang@arm.com>
Reviewed-on: https://review.gerrithub.io/424470
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
2018-11-05 22:15:41 +00:00

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942 B
Markdown

# System Configuration User Guide {#system_configuration}
This system configuration guide describes how to configure a system for use with SPDK.
# IOMMU configuration {#iommu_config}
An IOMMU may be present and enabled on many platforms. When an IOMMU is present and enabled, it is
recommended that SPDK applications are deployed with the `vfio-pci` kernel driver. SPDK's
`scripts/setup.sh` script will automatically select `vfio-pci` in this case.
However, some devices do not function correctly when bound to `vfio-pci` and instead must be
attached to the `uio_pci_generic` kernel driver. In that case, users should take care to disable
the IOMMU or to set it into passthrough mode prior to running `scripts/setup.sh`.
To disable the IOMMU or place it into passthrough mode, add `intel_iommu=off`
or `amd_iommu=off` or `intel_iommu=on iommu=pt` to the GRUB command line on
x86_64 system, or add `iommu.passthrough=1` on arm64 systems.