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[PATCH v2 3/4] hw/vfio: Add helper to retrieve device feature

Shameer Kolothum posted 4 patches 3 weeks, 6 days ago
There is a newer version of this series
[PATCH v2 3/4] hw/vfio: Add helper to retrieve device feature
Posted by Shameer Kolothum 3 weeks, 6 days ago 
Add vfio_device_get_feature() as a common helper to retrieve
VFIO device features.

No functional change intended.

Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
---
 hw/vfio/container.c           |  2 +-
 hw/vfio/device.c              | 10 ++++++++++
 hw/vfio/listener.c            |  4 ++--
 include/hw/vfio/vfio-device.h |  3 +++
 4 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index 5993d90545..b0cbcf0f4a 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -208,7 +208,7 @@ static int vfio_device_dma_logging_report(VFIODevice *vbasedev, hwaddr iova,
     feature->flags = VFIO_DEVICE_FEATURE_GET |
                      VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT;
 
-    return vbasedev->io_ops->device_feature(vbasedev, feature);
+    return vfio_device_get_feature(vbasedev, feature);
 }
 
 static int vfio_container_iommu_query_dirty_bitmap(
diff --git a/hw/vfio/device.c b/hw/vfio/device.c
index 100532f35d..0d9f42a1f0 100644
--- a/hw/vfio/device.c
+++ b/hw/vfio/device.c
@@ -516,6 +516,7 @@ void vfio_device_unprepare(VFIODevice *vbasedev)
     vbasedev->bcontainer = NULL;
 }
 
+
 bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev)
 {
     VFIOPCIDevice *vdev = vfio_pci_from_vfio_device(vbasedev);
@@ -527,6 +528,15 @@ bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev)
     return false;
 }
 
+int vfio_device_get_feature(VFIODevice *vbasedev,
+                            struct vfio_device_feature *feature)
+{
+    if (!vbasedev->io_ops || !vbasedev->io_ops->device_feature) {
+        return -EINVAL;
+    }
+    return vbasedev->io_ops->device_feature(vbasedev, feature);
+}
+
 /*
  * Traditional ioctl() based io
  */
diff --git a/hw/vfio/listener.c b/hw/vfio/listener.c
index 7af0107535..d00fc87f3b 100644
--- a/hw/vfio/listener.c
+++ b/hw/vfio/listener.c
@@ -879,7 +879,7 @@ static void vfio_devices_dma_logging_stop(VFIOContainer *bcontainer)
             continue;
         }
 
-        ret = vbasedev->io_ops->device_feature(vbasedev, feature);
+        ret = vfio_device_get_feature(vbasedev, feature);
 
         if (ret != 0) {
             warn_report("%s: Failed to stop DMA logging, err %d (%s)",
@@ -984,7 +984,7 @@ static bool vfio_devices_dma_logging_start(VFIOContainer *bcontainer,
             continue;
         }
 
-        ret = vbasedev->io_ops->device_feature(vbasedev, feature);
+        ret = vfio_device_get_feature(vbasedev, feature);
         if (ret) {
             error_setg_errno(errp, -ret, "%s: Failed to start DMA logging",
                              vbasedev->name);
diff --git a/include/hw/vfio/vfio-device.h b/include/hw/vfio/vfio-device.h
index 0bc877ff62..315dbb742a 100644
--- a/include/hw/vfio/vfio-device.h
+++ b/include/hw/vfio/vfio-device.h
@@ -259,6 +259,9 @@ void vfio_device_unprepare(VFIODevice *vbasedev);
 
 bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev);
 
+int vfio_device_get_feature(VFIODevice *vbasedev,
+                            struct vfio_device_feature *feature);
+
 int vfio_device_get_region_info(VFIODevice *vbasedev, int index,
                                 struct vfio_region_info **info);
 int vfio_device_get_region_info_type(VFIODevice *vbasedev, uint32_t type,
-- 
2.43.0
Re: [PATCH v2 3/4] hw/vfio: Add helper to retrieve device feature
Posted by Cédric Le Goater 3 weeks, 3 days ago 
On 1/13/26 12:37, Shameer Kolothum wrote:
> Add vfio_device_get_feature() as a common helper to retrieve
> VFIO device features.
> 
> No functional change intended.
> 
> Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
> ---
>   hw/vfio/container.c           |  2 +-
>   hw/vfio/device.c              | 10 ++++++++++
>   hw/vfio/listener.c            |  4 ++--
>   include/hw/vfio/vfio-device.h |  3 +++
>   4 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/vfio/container.c b/hw/vfio/container.c
> index 5993d90545..b0cbcf0f4a 100644
> --- a/hw/vfio/container.c
> +++ b/hw/vfio/container.c
> @@ -208,7 +208,7 @@ static int vfio_device_dma_logging_report(VFIODevice *vbasedev, hwaddr iova,
>       feature->flags = VFIO_DEVICE_FEATURE_GET |
>                        VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT;
>   
> -    return vbasedev->io_ops->device_feature(vbasedev, feature);
> +    return vfio_device_get_feature(vbasedev, feature);
>   }
>   
>   static int vfio_container_iommu_query_dirty_bitmap(
> diff --git a/hw/vfio/device.c b/hw/vfio/device.c
> index 100532f35d..0d9f42a1f0 100644
> --- a/hw/vfio/device.c
> +++ b/hw/vfio/device.c
> @@ -516,6 +516,7 @@ void vfio_device_unprepare(VFIODevice *vbasedev)
>       vbasedev->bcontainer = NULL;
>   }
>   
> +
>   bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev)
>   {
>       VFIOPCIDevice *vdev = vfio_pci_from_vfio_device(vbasedev);
> @@ -527,6 +528,15 @@ bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev)
>       return false;
>   }
>   
> +int vfio_device_get_feature(VFIODevice *vbasedev,
> +                            struct vfio_device_feature *feature)
> +{
> +    if (!vbasedev->io_ops || !vbasedev->io_ops->device_feature) {
> +        return -EINVAL;
> +    }
> +    return vbasedev->io_ops->device_feature(vbasedev, feature);
> +}
> +
>   /*
>    * Traditional ioctl() based io
>    */
> diff --git a/hw/vfio/listener.c b/hw/vfio/listener.c
> index 7af0107535..d00fc87f3b 100644
> --- a/hw/vfio/listener.c
> +++ b/hw/vfio/listener.c
> @@ -879,7 +879,7 @@ static void vfio_devices_dma_logging_stop(VFIOContainer *bcontainer)
>               continue;
>           }
>   
> -        ret = vbasedev->io_ops->device_feature(vbasedev, feature);
> +        ret = vfio_device_get_feature(vbasedev, feature);
>   
>           if (ret != 0) {
>               warn_report("%s: Failed to stop DMA logging, err %d (%s)",
> @@ -984,7 +984,7 @@ static bool vfio_devices_dma_logging_start(VFIOContainer *bcontainer,
>               continue;
>           }
>   
> -        ret = vbasedev->io_ops->device_feature(vbasedev, feature);
> +        ret = vfio_device_get_feature(vbasedev, feature);
>           if (ret) {
>               error_setg_errno(errp, -ret, "%s: Failed to start DMA logging",
>                                vbasedev->name);
> diff --git a/include/hw/vfio/vfio-device.h b/include/hw/vfio/vfio-device.h
> index 0bc877ff62..315dbb742a 100644
> --- a/include/hw/vfio/vfio-device.h
> +++ b/include/hw/vfio/vfio-device.h
> @@ -259,6 +259,9 @@ void vfio_device_unprepare(VFIODevice *vbasedev);
>   
>   bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev);
>   
> +int vfio_device_get_feature(VFIODevice *vbasedev,
> +                            struct vfio_device_feature *feature);
> +
>   int vfio_device_get_region_info(VFIODevice *vbasedev, int index,
>                                   struct vfio_region_info **info);
>   int vfio_device_get_region_info_type(VFIODevice *vbasedev, uint32_t type,

Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.
Re: [PATCH v2 3/4] hw/vfio: Add helper to retrieve device feature
Posted by Jonathan Cameron via qemu development 3 weeks, 5 days ago 
On Tue, 13 Jan 2026 11:37:53 +0000
Shameer Kolothum <skolothumtho@nvidia.com> wrote:

> Add vfio_device_get_feature() as a common helper to retrieve
> VFIO device features.
> 
> No functional change intended.
> 
> Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
Hi Shameer,

Happy new year.

Trivial thing noticed whilst glancing at this.

> diff --git a/hw/vfio/device.c b/hw/vfio/device.c
> index 100532f35d..0d9f42a1f0 100644
> --- a/hw/vfio/device.c
> +++ b/hw/vfio/device.c
> @@ -516,6 +516,7 @@ void vfio_device_unprepare(VFIODevice *vbasedev)
>      vbasedev->bcontainer = NULL;
>  }
>  
> +

Stray change.

>  bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev)
>  {
>      VFIOPCIDevice *vdev = vfio_pci_from_vfio_device(vbasedev);
> @@ -527,6 +528,15 @@ bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev)
>      return false;
>  }
Re: [PATCH v2 3/4] hw/vfio: Add helper to retrieve device feature
Posted by Cédric Le Goater 3 weeks, 3 days ago 
On 1/14/26 11:19, Jonathan Cameron wrote:
> On Tue, 13 Jan 2026 11:37:53 +0000
> Shameer Kolothum <skolothumtho@nvidia.com> wrote:
> 
>> Add vfio_device_get_feature() as a common helper to retrieve
>> VFIO device features.
>>
>> No functional change intended.
>>
>> Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
> Hi Shameer,
> 
> Happy new year.
> 
> Trivial thing noticed whilst glancing at this.
> 
>> diff --git a/hw/vfio/device.c b/hw/vfio/device.c
>> index 100532f35d..0d9f42a1f0 100644
>> --- a/hw/vfio/device.c
>> +++ b/hw/vfio/device.c
>> @@ -516,6 +516,7 @@ void vfio_device_unprepare(VFIODevice *vbasedev)
>>       vbasedev->bcontainer = NULL;
>>   }
>>   
>> +
> 
> Stray change.

Yeah I can fix that when applying. No need to resend.

Thanks,

C.
> 
>>   bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev)
>>   {
>>       VFIOPCIDevice *vdev = vfio_pci_from_vfio_device(vbasedev);
>> @@ -527,6 +528,15 @@ bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev)
>>       return false;
>>   }
>

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