Re: [Qemu-devel] [RFC PATCH 5/8] VFIO: Add new IOTCL for PASID Table bind propagation

[Jean-Philippe Brucker]

On 26/04/17 11:12, Liu, Yi L wrote:
> From: "Liu, Yi L" <address@hidden>
> 
> This patch adds VFIO_IOMMU_SVM_BIND_TASK for potential PASID table
> binding requests.
> 
> On VT-d, this IOCTL cmd would be used to link the guest PASID page table
> to host. While for other vendors, it may also be used to support other
> kind of SVM bind request. Previously, there is a discussion on it with
> ARM engineer. It can be found by the link below. This IOCTL cmd may
> support SVM PASID bind request from userspace driver, or page table(cr3)
> bind request from guest. These SVM bind requests would be supported by
> adding different flags. e.g. VFIO_SVM_BIND_PASID is added to support
> PASID bind from userspace driver, VFIO_SVM_BIND_PGTABLE is added to
> support page table bind from guest.
> 
> https://patchwork.kernel.org/patch/9594231/
> 
> Signed-off-by: Liu, Yi L <address@hidden>
> ---
>  include/uapi/linux/vfio.h | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index 519eff3..6b97987 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -547,6 +547,23 @@ struct vfio_iommu_type1_dma_unmap {
>  #define VFIO_IOMMU_ENABLE    _IO(VFIO_TYPE, VFIO_BASE + 15)
>  #define VFIO_IOMMU_DISABLE   _IO(VFIO_TYPE, VFIO_BASE + 16)
>  
> +/* IOCTL for Shared Virtual Memory Bind */
> +struct vfio_device_svm {
> +     __u32   argsz;
> +#define VFIO_SVM_BIND_PASIDTBL       (1 << 0) /* Bind PASID Table */
> +#define VFIO_SVM_BIND_PASID  (1 << 1) /* Bind PASID from userspace driver */
> +#define VFIO_SVM_BIND_PGTABLE        (1 << 2) /* Bind guest mmu page table */
> +     __u32   flags;
> +     __u32   length;
> +     __u8    data[];
> +};
> +
> +#define VFIO_SVM_TYPE_MASK   (VFIO_SVM_BIND_PASIDTBL | \
> +                             VFIO_SVM_BIND_PASID | \
> +                             VFIO_SVM_BIND_PGTABLE)
> +
> +#define VFIO_IOMMU_SVM_BIND_TASK     _IO(VFIO_TYPE, VFIO_BASE + 22)

This could be called "VFIO_IOMMU_SVM_BIND, since it will be used both to
bind tables and individual tasks.

Thanks,
Jean