Using the PCI VFIO interface allows userland, a.k.a. QEMU, to retrieve ZPCI specific information without knowing Z specific identifiers like the function ID or the function handle of the zPCI function hidden behind the PCI interface. By using the VFIO_IOMMU_GET_INFO ioctl we enter the vfio_iommu_type1 ioctl callback and can insert there the treatment for a new Z specific capability. Once in vfio_iommu_type1 we can retrieve the real iommu device, s390_iommu and call the get_attr iommu operation's callback in which we can retrieve the zdev device and start clp operations to retrieve Z specific values the guest driver is concerned with. To share the code with arch/s390/pci/pci_clp.c the original functions in pci_clp.c to query PCI functions and PCI functions group are modified so that they can be exported. A new function clp_query_pci() replaces clp_query_pci_fn() and the previous calls to clp_query_pci_fn() and clp_query_pci_fngrp() are replaced with calls to zdev_query_pci_fn() and zdev_query_pci_fngrp() using a zdev pointer as argument. Pierre Morel (4): s390: pci: Exporting access to CLP PCI function and PCI group vfio: vfio_iommu_type1: Define VFIO_IOMMU_INFO_CAPABILITIES s390: iommu: Adding get attributes for s390_iommu vfio: vfio_iommu_type1: implement VFIO_IOMMU_INFO_CAPABILITIES arch/s390/include/asm/pci.h | 3 + arch/s390/pci/pci_clp.c | 70 ++++++++++++----------- drivers/iommu/s390-iommu.c | 77 +++++++++++++++++++++++++ drivers/vfio/vfio_iommu_type1.c | 122 +++++++++++++++++++++++++++++++++++++++- include/linux/iommu.h | 4 ++ include/uapi/linux/vfio.h | 67 ++++++++++++++++++++++ 6 files changed, 308 insertions(+), 35 deletions(-) -- 2.7.4 Changelog >From V1: - no export of the symbol of the new zPCI CLP functions (Robin) - adding descriptions for the VFIO capabilities (Alex) - defining the structure of the data retrieved through VFIO_IOMMU_GET_INFO (Alex) - code modifications to allow architecture independence for the capabilities (Alex)
