[0/4] Retrieving zPCI specific info with VFIO

Message

Pierre Morel May 10, 2019, 8:22 a.m. UTC

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.

These two functions are exported to be used from out of the s390_iommu
code.

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         | 72 ++++++++++++++++---------------
 drivers/iommu/s390-iommu.c      | 77 +++++++++++++++++++++++++++++++++
 drivers/vfio/vfio_iommu_type1.c | 95 ++++++++++++++++++++++++++++++++++++++++-
 include/linux/iommu.h           |  4 ++
 include/uapi/linux/vfio.h       | 10 +++++
 6 files changed, 226 insertions(+), 35 deletions(-)