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[PATCH v11 06/10] vfio/region: Add a helper to get region index from memory region

Vivek Kasireddy posted 10 patches 3 weeks, 6 days ago
There is a newer version of this series
[PATCH v11 06/10] vfio/region: Add a helper to get region index from memory region
Posted by Vivek Kasireddy 3 weeks, 6 days ago 
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 <alex@shazbot.org>
Cc: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
---
 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(region->mem),
                                         enabled);
 }
+
+int vfio_get_region_index_from_mr(MemoryRegion *mr)
+{
+    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. */
-- 
2.53.0
Re: [PATCH v11 06/10] vfio/region: Add a helper to get region index from memory region
Posted by Cédric Le Goater 3 weeks ago 
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 <alex@shazbot.org>
> Cc: Cédric Le Goater <clg@redhat.com>
> Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
> ---
>   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(region->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.

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. */
Re: [PATCH v11 06/10] vfio/region: Add a helper to get region index from memory region
Posted by Cédric Le Goater 3 weeks ago 
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 <alex@shazbot.org>
>> Cc: Cédric Le Goater <clg@redhat.com>
>> Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
>> ---
>>   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(region->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.

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. */
>
RE: [PATCH v11 06/10] vfio/region: Add a helper to get region index from memory region
Posted by Kasireddy, Vivek 2 weeks, 6 days ago 
> 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 <alex@shazbot.org>
> >> Cc: Cédric Le Goater <clg@redhat.com>
> >> Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
> >> ---
> >>   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. */
> >

Patchew 2.1-devel-ea86937

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