> Subject: Re: [PATCH v11 06/10] vfio/region: Add a helper to get region
> index from memory region
>
> On 3/17/26 15:41, Cédric Le Goater wrote:
> > On 3/11/26 03:50, Vivek Kasireddy wrote:
> >> Having a way to figure out the region index (or bar) associated
> >> with a memory region is helpful in various scenarios. For example,
> >> this capability can be useful in retrieving the region info needed
> >> for mapping a part of a VFIO region or creating a dmabuf.
> >>
> >> Cc: Alex Williamson <[email protected]>
> >> Cc: Cédric Le Goater <[email protected]>
> >> Signed-off-by: Vivek Kasireddy <[email protected]>
> >> ---
> >> hw/vfio/region.c | 14 ++++++++++++++
> >> include/hw/vfio/vfio-device.h | 10 ++++++++++
> >> 2 files changed, 24 insertions(+)
> >>
> >> diff --git a/hw/vfio/region.c b/hw/vfio/region.c
> >> index 47fdc2df34..4cb92216ef 100644
> >> --- a/hw/vfio/region.c
> >> +++ b/hw/vfio/region.c
> >> @@ -539,3 +539,17 @@ void
> vfio_region_mmaps_set_enabled(VFIORegion *region, bool enabled)
> >> trace_vfio_region_mmaps_set_enabled(memory_region_name(re
> gion->mem),
> >> enabled);
> >> }
> >> +
> >> +int vfio_get_region_index_from_mr(MemoryRegion *mr)
> >
> >
> > I think you can move this routine as a static in device.c now. No need
> > to export a service.
>
> you can't because of vfio_region_ops.
>
> Returning a VFIORegion seems cleaner though.
I agree. Will make the change in the next version.
Thanks,
Vivek
>
> Thanks,
>
> C.
>
>
> >
> > Thanks,
> >
> > C.
> >
> >> +{
> >> + VFIORegion *region;
> >> +
> >> + while (mr->container) {
> >> + if (mr->ops == &vfio_region_ops) {
> >> + region = mr->opaque;
> >> + return region->nr;
> >> + }
> >> + mr = mr->container;
> >> + }
> >> + return -1;
> >> +}
> >> diff --git a/include/hw/vfio/vfio-device.h b/include/hw/vfio/vfio-
> device.h
> >> index 828a31c006..596c7f5a10 100644
> >> --- a/include/hw/vfio/vfio-device.h
> >> +++ b/include/hw/vfio/vfio-device.h
> >> @@ -308,6 +308,16 @@ bool
> vfio_device_has_region_cap(VFIODevice *vbasedev, int region, uint16_t
> cap_t
> >> int vfio_device_get_irq_info(VFIODevice *vbasedev, int index,
> >> struct vfio_irq_info *info);
> >> +
> >> +/**
> >> + * Return the region index associated with a given MemoryRegion.
> The index
> >> + * can be useful in retrieving region info.
> >> + *
> >> + * @mr: MemoryRegion to use
> >> + *
> >> + * Returns the region index or -1 on error.
> >> + */
> >> +int vfio_get_region_index_from_mr(MemoryRegion *mr);
> >> #endif
> >> /* Returns 0 on success, or a negative errno. */
> >
