Re: [RFC PATCH V3 00/26] vfio/pci: Back guest interrupts from Interrupt Message Store (IMS)

[Reinette Chatre]

Hi Alex,

On 11/7/2023 3:06 PM, Alex Williamson wrote:
> That also sort of illustrates the point though that this series is
> taking a pretty broad approach to slicing up vfio-pci-core's SET_IRQS
> ioctl code path, enabling support for IMS backed interrupts, but in
> effect complicating the whole thing without any actual consumer to
> justify the complication.  Meanwhile I think the goal is to reduce
> complication to a driver that doesn't exist yet.  So it currently seems
> like a poor trade-off.
> 
> This driver that doesn't exist yet could implement its own SET_IRQS
> ioctl that backs MSI-X with IMS as a starting point.  Presumably we
> expect multiple drivers to require this behavior, so common code makes
> sense, but the rest of us in the community can't really evaluate how
> much it makes sense to slice the common code without seeing that
> implementation and how it might leverage, if not directly use, the
> existing core code.

I understand. I'm hearing the same from you and Jason. I plan to
work on addressing your feedback but will only share it when it can be
accompanied by a draft of the IDXD VDCM driver. Please let me know
if you prefer a different approach.

Reinette