Re: [PATCH v10 Kernel 2/5] vfio iommu: Adds flag to indicate dirty pages tracking capability support

[Alex Williamson]

On Tue, 17 Dec 2019 01:51:37 +0530
Kirti Wankhede <address@hidden> wrote:

> Flag VFIO_IOMMU_INFO_DIRTY_PGS in VFIO_IOMMU_GET_INFO indicates that driver
> support dirty pages tracking.
> 
> Signed-off-by: Kirti Wankhede <address@hidden>
> Reviewed-by: Neo Jia <address@hidden>
> ---
>  drivers/vfio/vfio_iommu_type1.c | 3 ++-
>  include/uapi/linux/vfio.h       | 5 +++--
>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 2ada8e6cdb88..3f6b04f2334f 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -2234,7 +2234,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
>                       info.cap_offset = 0; /* output, no-recopy necessary */
>               }
>  
> -             info.flags = VFIO_IOMMU_INFO_PGSIZES;
> +             info.flags = VFIO_IOMMU_INFO_PGSIZES |
> +                          VFIO_IOMMU_INFO_DIRTY_PGS;

Type1 shouldn't advertise it until it's supported though, right?
Thanks,

Alex

>  
>               info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
>  
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index a0817ba267c1..81847ed54eb7 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -900,8 +900,9 @@ struct vfio_device_ioeventfd {
>  struct vfio_iommu_type1_info {
>       __u32   argsz;
>       __u32   flags;
> -#define VFIO_IOMMU_INFO_PGSIZES (1 << 0)     /* supported page sizes info */
> -#define VFIO_IOMMU_INFO_CAPS (1 << 1)        /* Info supports caps */
> +#define VFIO_IOMMU_INFO_PGSIZES   (1 << 0) /* supported page sizes info */
> +#define VFIO_IOMMU_INFO_CAPS      (1 << 1) /* Info supports caps */
> +#define VFIO_IOMMU_INFO_DIRTY_PGS (1 << 2) /* supports dirty page tracking */
>       __u64   iova_pgsizes;   /* Bitmap of supported page sizes */
>       __u32   cap_offset;     /* Offset within info struct of first cap */
>  };