[PATCH v3 0/5] Error recovery for zPCI passthrough devices

[Farhan Ali <alifm@linux.ibm.com>]

Hi,

This patch series introduces support for error recovery for passthrough
PCI devices on System Z (s390x). This is the user space component for the Linux
kernel patches [1]. For QEMU on eventfd notification for PCI error from vfio-pci
driver we call the vfio error handler. We can use a per device error
handler callback to override the default vfio error handler. 

For s390x specific error handler, we retrieve the architecture specific PCI error
information and inject the information into the guest. Once the guest receives
the error information, the guest drivers will drive the error recovery.
Typically recovery involves a device reset which translate to CLP
disable/enable cycle for the device.

I would appreciate some feedback on this patch series.

Thanks
Farhan

[1] https://lore.kernel.org/all/20250924171628.826-1-alifm@linux.ibm.com/

ChangeLog
---------
v2 https://lore.kernel.org/qemu-devel/20250825212434.2255-1-alifm@linux.ibm.com/
v2 -> v3
    - Update arch_err_handler to err_handler and include Error ** in
    function definition. (patch 2)

    - Introduce helper function to hide the internal indirection of device_feature()
    (patch 3)

    - Update function definitions to include Error ** (patch 4)
    


v1 https://lore.kernel.org/qemu-devel/20250813174152.1238-1-alifm@linux.ibm.com/
v1 -> v2
   - Use VFIO_DEVICE_FEATURE ioctl to get device error information.
   (Based on Alex's feedback on kernel series)

Farhan Ali (5):
  [NOTFORMERGE] linux-headers: Update for zpci vfio device
  vfio/pci: Add an error handler callback
  vfio: Introduce vfio_device_feature helper function
  s390x/pci: Add PCI error handling for vfio pci devices
  s390x/pci: Reset a device in error state

 hw/s390x/s390-pci-bus.c          | 16 ++++++
 hw/s390x/s390-pci-vfio.c         | 87 ++++++++++++++++++++++++++++++++
 hw/vfio/device.c                 |  6 +++
 hw/vfio/pci.c                    |  8 +++
 hw/vfio/pci.h                    |  1 +
 include/hw/s390x/s390-pci-bus.h  |  1 +
 include/hw/s390x/s390-pci-vfio.h |  8 +++
 include/hw/vfio/vfio-device.h    |  2 +
 linux-headers/linux/vfio.h       | 15 ++++++
 9 files changed, 144 insertions(+)

-- 
2.43.0