Re: [PATCH v11 5/5] vfio-pci/zdev: Add VFIO FMB device features

[Alex Williamson]

On Wed, 28 Oct 2026 11:43:52 -0400
Omar Elghoul <oelghoul@xxxxxxxxxxxxx> wrote:

> Introduce new VFIO features for zPCI devices to provide FMB passthrough to
> userspace.
> 
> Allow the user to enable or disable the FMB using the SET-only feature
> VFIO_DEVICE_FEATURE_ZPCI_FMB_ENABLE. Likewise allow the user to read the
> latest FMB using the GET-only feature VFIO_DEVICE_FEATURE_ZPCI_FMB_READ
> in the case when the FMB is enabled.
> 
> Signed-off-by: Omar Elghoul <oelghoul@xxxxxxxxxxxxx>
> ---
>  drivers/vfio/pci/vfio_pci_core.c |  4 ++
>  drivers/vfio/pci/vfio_pci_priv.h | 18 +++++++++
>  drivers/vfio/pci/vfio_pci_zdev.c | 64 ++++++++++++++++++++++++++++++++
>  include/uapi/linux/vfio.h        | 30 +++++++++++++++
>  4 files changed, 116 insertions(+)

I think the only thing we never closed on from the vfio side is the
merge plan.  If this goes in via s390 I'd want a topic branch against
rc1 since there are a couple series floating around contesting for the
same feature numbers.  Thanks,

Alex