Following Robin's series [1] addressing MSI IOMMU mapping for devices attached to a DMA ops domain, my previous 3 part series (v12) lost most of its consistency. msi-iommu API role now is handled at dma-iommu level while MSI doorbell registration API only is used for security assessment. Also MSI layer part is not needed anymore since mapping directly is done in the compose callback. Here I propose an alternative approach, based on [1]. This approach was discussed at the KVM forum with Christoffer Dall and Marc Zyngier, and was suggested by Christoffer. The idea is we could let the iommu layer transparently allocate MSI frame IOVAs in the holes left between UNMANAGED iova slots, set by the iommu-api user. This series introduces a new IOMMU domain type that allows mixing of unmanaged and managed IOVA slots. We define an IOVA domain whose aperture covers the GPA address range. Each time the IOMMU-API user maps iova/pa, we reserve the IOVA range to prevent the iova allocator from using it for MSI mapping. This simplifies the user part which does not need anymore to provide an IOVA aperture anymore. The current series does not address the interrupt safety assessment, which may be considered as a separate issue. Currently the assignemnt is considered as unsafe, on ARM (even with a GICv3 ITS). Please let me know what is your feeling wrt this alternative approach. dependency: [1] [PATCH v7 00/22] Generic DT bindings for PCI IOMMUs and ARM SMMU http://www.spinics.net/lists/arm-kernel/msg531110.html Best Regards Eric Testing: - functional on ARM64 AMD Overdrive HW (single GICv2m frame). Lack of contexts prevents me from testing multiple assignment. Git: complete series available at https://github.com/eauger/linux/tree/generic-v7-pcie-passthru-redesign-rfc previous: https://github.com/eauger/linux/tree/v4.7-rc7-passthrough-v12 the above branch includes a temporary patch to work around a ThunderX pci bus reset crash (which I think unrelated to this series): "vfio: pci: HACK! workaround thunderx pci_try_reset_bus crash" Do not take this one for other platforms. Eric Auger (10): iommu: Add iommu_domain_msi_geometry and DOMAIN_ATTR_MSI_GEOMETRY iommu: Introduce IOMMU_CAP_TRANSLATE_MSI capability iommu: Introduce IOMMU_DOMAIN_MIXED iommu/dma: iommu_dma_(un)map_mixed iommu/arm-smmu: Allow IOMMU_DOMAIN_MIXED domain allocation iommu: Use IOMMU_DOMAIN_MIXED typed domain when IOMMU translates MSI vfio/type1: Sets the IOVA window in case MSI IOVA need to be allocated vfio/type1: Reserve IOVAs for IOMMU_DOMAIN_MIXED domains iommu/arm-smmu: Do not advertise IOMMU_CAP_INTR_REMAP iommu/arm-smmu: Advertise IOMMU_CAP_TRANSLATE_MSI Robin Murphy (1): iommu/dma: Allow MSI-only cookies drivers/iommu/arm-smmu-v3.c | 8 +++- drivers/iommu/arm-smmu.c | 8 +++- drivers/iommu/dma-iommu.c | 91 +++++++++++++++++++++++++++++++++++++++++ drivers/iommu/iommu.c | 10 ++++- drivers/vfio/vfio_iommu_type1.c | 48 ++++++++++++++++++---- include/linux/dma-iommu.h | 27 ++++++++++++ include/linux/iommu.h | 23 +++++++++++ 7 files changed, 203 insertions(+), 12 deletions(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
