Re: [PATCH v6 0/2] Error recovery for zPCI passthrough devices

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

Hi,

Polite ping for this series.

Thanks

Farhan

On 9/22/2026 10:17 AM, Farhan Ali wrote:
> 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]. The kernel patches were merged for 7.3 release.
>
> The current design for QEMU updates the callback for vfio error notifier to
> an s390x specific error handler if the kernel supports the new device
> feature VFIO_DEVICE_FEATURE_ZPCI_ERROR, for s390 vfio-pci devices. So now
> on an eventfd notification for error notifier it will invoke the s390x
> specific error handler.  The s390x error handler will 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/20260818164326.387bb27b@shazbot.org/
>
> ChangeLog
> ---------
> v5 https://lore.kernel.org/all/20260914174420.12309-1-alifm@linux.ibm.com/
> v5 -> v6
>      - Address Cedric's feedback (patch 1).
>      - Update error handling to follow QEMU style (patch 1).
>      - Rebase on master.
>      - Remove linux-headers update as latest QEMU master has the VFIO headers
>      merged.
>
> v4 https://lore.kernel.org/all/20260831183151.12626-1-alifm@linux.ibm.com/
> v4 -> v5
>      - Remove err_handler() callback in vfio pci core.
>      - Update the vfio error notifier callback to an s390x specific callback
>      for s390x devices
>      - Include linux headers for 7.3-rc3.
> v3 https://lore.kernel.org/qemu-devel/20250925174852.1302-1-alifm@linux.ibm.com/
> v3 -> v4
>      - Include linux headers for 7.3-rc1.
>      - Rework VFIO API changes based on the kernel API (patch 3).
>      - Address Markus's comments from v3 (patch 2).
>
> 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 (2):
>    s390x/pci: Add PCI error handling for vfio pci devices
>    s390x/pci: Reset a device in error state
>
>   hw/s390x/s390-pci-bus.c          |  13 ++++
>   hw/s390x/s390-pci-vfio-stubs.c   |  10 +++
>   hw/s390x/s390-pci-vfio.c         | 130 +++++++++++++++++++++++++++++++
>   include/hw/s390x/s390-pci-bus.h  |   1 +
>   include/hw/s390x/s390-pci-vfio.h |   2 +
>   5 files changed, 156 insertions(+)
>