Hi, Currently, the MSI_IOVA_BASE address is hard-coded to 0x80000000, assuming that all platforms have this address available for MSI IOVA reservation. However, this is not always the case, as some platforms reserve this address for other purposes. Consequently, these platforms cannot reserve the MSI_IOVA_BASE address for MSI.
There was an [1] attempt to fix this problem by passing the MSI IOVA base as a kernel command line parameter. This patch series aims to address the issue by reserving faulty MSI_IOVA and selecting suitable MSI IOVA address for a given platform. This approach accommodates platforms that do not have the default MSI base address available for MSI reservation. [1]: https://lore.kernel.org/lkml/20200914181307.117792-1-vemeg...@linux.microsoft.com/ Thanks, Shyam --- v3: - Drop "arm,smmu-faulty-msi-iova" property change - Fix iommu driver device tree configuration for PCI devices - Use "iommu-addresses" property to identify reserved MSI IOVA regions, and introduce an additional MSI_IOVA_BASE2 macro to select a suitable MSI IOVA base if the default overlaps with a reserved region (suggested by Jason) v2: - add new dts property to hold faulty MSI IOVA and select appropriate MSI IOVA address Link: https://lore.kernel.org/linux-iommu/20250410225030.2528385-1-shyamsa...@linux.microsoft.com/ v1: Link: https://lore.kernel.org/linux-iommu/20250116232307.1436693-1-shyamsa...@linux.microsoft.com/ Shyam Saini (3): arm-smmu: move MSI_IOVA macro definitions iommu/of: fix device tree configuration for PCI devices arm-smmu: select suitable MSI IOVA drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 27 ++++++++++++++----- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 3 --- drivers/iommu/arm/arm-smmu/arm-smmu.c | 30 ++++++++++++++------- drivers/iommu/of_iommu.c | 11 ++++++++ drivers/iommu/virtio-iommu.c | 2 -- include/linux/iommu.h | 28 +++++++++++++++++++ 6 files changed, 79 insertions(+), 22 deletions(-) -- 2.34.1
