Re: [PATCH v4 0/4] Retrieving zPCI specific info with VFIO

[Matthew Rosato <mjrosato@linux.ibm.com>]

ping

On 9/6/19 8:13 PM, Matthew Rosato wrote:
> Note: These patches by Pierre got lost in the ether a few months back
> as he has been unavailable to carry them forward.  I've made changes
> based upon comments received on his last version.
> 
> We define a new configuration entry for VFIO/PCI, VFIO_PCI_ZDEV
> to configure access to a zPCI region dedicated for retrieving
> zPCI features.
> 
> When the VFIO_PCI_ZDEV feature is configured we initialize
> a new device region, VFIO_REGION_SUBTYPE_ZDEV_CLP, to hold
> the information from the ZPCI device the userland needs to
> give to a guest driving the zPCI function.
> 
> 
> Note that in the current state we do not use the CLP instructions
> to access the firmware but get the information directly from
> the zdev device.
> 
> -This means that the patch 1, "s390: pci: Exporting access to CLP PCI
> function and PCI group" is not used and can be let out of this series
> without denying the good working of the other patches.
> - But we will need this later, eventually in the next iteration
>   to retrieve values not being saved inside the zdev structure.
>   like maxstbl and the PCI supported version
> 
> 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.
> 
> Changes since v3:
> - New patch: define maxstbl
> - Remove CLP_UTIL_STR_LEN references from uapi header
> - Fix broken ifdef CONFIG_VFIO_PCI_ZDEV
> - Change Kconfig option from tristate to bool
> - Remove VFIO_REGION_TYPE_IBM_ZDEV, move VFIO_REGION_SUBTYPE_ZDEV_CLP to a 1014 subtype
> - reject iswrite in .rw callback
> - Remove rw restriction on identical buffer sizes
> - Allow arbitrary sized read
> 
> Pierre Morel (4):
>   s390: pci: Exporting access to CLP PCI function and PCI group
>   s390: pci: Define the maxstbl CLP response entry
>   vfio: zpci: defining the VFIO headers
>   vfio: pci: Using a device region to retrieve zPCI information
> 
>  arch/s390/include/asm/pci.h         |  3 ++
>  arch/s390/include/asm/pci_clp.h     |  2 +-
>  arch/s390/pci/pci_clp.c             | 71 ++++++++++++++++---------------
>  drivers/vfio/pci/Kconfig            |  7 +++
>  drivers/vfio/pci/Makefile           |  1 +
>  drivers/vfio/pci/vfio_pci.c         |  9 ++++
>  drivers/vfio/pci/vfio_pci_private.h | 10 +++++
>  drivers/vfio/pci/vfio_pci_zdev.c    | 85 +++++++++++++++++++++++++++++++++++++
>  include/uapi/linux/vfio.h           |  1 +
>  include/uapi/linux/vfio_zdev.h      | 35 +++++++++++++++
>  10 files changed, 189 insertions(+), 35 deletions(-)
>  create mode 100644 drivers/vfio/pci/vfio_pci_zdev.c
>  create mode 100644 include/uapi/linux/vfio_zdev.h
>