Hi Alex,
Eric asked if we will to have data strcut other than struct iommu_nesting_info
type in the struct vfio_iommu_type1_info_cap_nesting @info[] field. I'm not
quit sure on it. I guess the answer may be not as VFIO's nesting support should
based on IOMMU UAPI. how about your opinion?
+#define VFIO_IOMMU_TYPE1_INFO_CAP_NESTING 3
+
+/*
+ * Reporting nesting info to user space.
+ *
+ * @info: the nesting info provided by IOMMU driver. Today
+ * it is expected to be a struct iommu_nesting_info
+ * data.
+ */
+struct vfio_iommu_type1_info_cap_nesting {
+ struct vfio_info_cap_header header;
+ __u32 flags;
+ __u32 padding;
+ __u8 info[];
+};
https://lore.kernel.org/linux-iommu/DM5PR11MB1435290B6CD561EC61027892C3690@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
Regards,
Yi Liu
> From: Liu, Yi L
> Sent: Tuesday, July 7, 2020 5:32 PM
>
[...]
> > >
> > >>> +
> > >>> +/*
> > >>> + * Reporting nesting info to user space.
> > >>> + *
> > >>> + * @info: the nesting info provided by IOMMU driver. Today
> > >>> + * it is expected to be a struct iommu_nesting_info
> > >>> + * data.
> > >> Is it expected to change?
> > >
> > > honestly, I'm not quite sure on it. I did considered to embed struct
> > > iommu_nesting_info here instead of using info[]. but I hesitated as
> > > using info[] may leave more flexibility on this struct. how about
> > > your opinion? perhaps it's fine to embed the struct
> > > iommu_nesting_info here as long as VFIO is setup nesting based on
> > > IOMMU UAPI.
> > >
> > >>> + */
> > >>> +struct vfio_iommu_type1_info_cap_nesting {
> > >>> + struct vfio_info_cap_header header;
> > >>> + __u32 flags;
> > >> You may document flags.
> > >
> > > sure. it's reserved for future.
> > >
> > > Regards,
> > > Yi Liu
> > >
> > >>> + __u32 padding;
> > >>> + __u8 info[];
> > >>> +};
> > >>> +
> > >>> #define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
> > >>>
> > >>> /**
> > >>>
> > >> Thanks
> > >>
> > >> Eric
> > >
