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References: <20231103171641.1703146-1-lulu@redhat.com> <20231103171641.1703146-4-lulu@redhat.com>
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From:   Jason Wang <jasowang@redhat.com>
Date:   Mon, 6 Nov 2023 15:30:13 +0800
Message-ID: <CACGkMEtVfHL2WPwxkYEfTKBE10uWfB2a75QQOO8rzn3=Y9FiBg@mail.gmail.com>
Subject: Re: [RFC v1 3/8] vhost: Add 3 new uapi to support iommufd
To:     Cindy Lu <lulu@redhat.com>
Cc:     mst@redhat.com, yi.l.liu@intel.com, jgg@nvidia.com,
        linux-kernel@vger.kernel.org,
        virtualization@lists.linux-foundation.org, netdev@vger.kernel.org
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On Sat, Nov 4, 2023 at 1:17=E2=80=AFAM Cindy Lu <lulu@redhat.com> wrote:
>
> VHOST_VDPA_SET_IOMMU_FD: bind the device to iommufd device
>
> VDPA_DEVICE_ATTACH_IOMMUFD_AS: Attach a vdpa device to an iommufd
> address space specified by IOAS id.
>
> VDPA_DEVICE_DETACH_IOMMUFD_AS: Detach a vdpa device
> from the iommufd address space
>
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---

[...]

> diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> index f5c48b61ab62..07e1b2c443ca 100644
> --- a/include/uapi/linux/vhost.h
> +++ b/include/uapi/linux/vhost.h
> @@ -219,4 +219,70 @@
>   */
>  #define VHOST_VDPA_RESUME              _IO(VHOST_VIRTIO, 0x7E)
>
> +/* vhost_vdpa_set_iommufd
> + * Input parameters:
> + * @iommufd: file descriptor from /dev/iommu; pass -1 to unset
> + * @iommufd_ioasid: IOAS identifier returned from ioctl(IOMMU_IOAS_ALLOC=
)
> + * Output parameters:
> + * @out_dev_id: device identifier
> + */
> +struct vhost_vdpa_set_iommufd {
> +       __s32 iommufd;
> +       __u32 iommufd_ioasid;
> +       __u32 out_dev_id;
> +};
> +
> +#define VHOST_VDPA_SET_IOMMU_FD \
> +       _IOW(VHOST_VIRTIO, 0x7F, struct vhost_vdpa_set_iommufd)
> +
> +/*
> + * VDPA_DEVICE_ATTACH_IOMMUFD_AS -
> + * _IOW(VHOST_VIRTIO, 0x7f, struct vdpa_device_attach_iommufd_as)
> + *
> + * Attach a vdpa device to an iommufd address space specified by IOAS
> + * id.
> + *
> + * Available only after a device has been bound to iommufd via
> + * VHOST_VDPA_SET_IOMMU_FD
> + *
> + * Undo by VDPA_DEVICE_DETACH_IOMMUFD_AS or device fd close.
> + *
> + * @argsz:     user filled size of this data.
> + * @flags:     must be 0.
> + * @ioas_id:   Input the target id which can represent an ioas
> + *             allocated via iommufd subsystem.
> + *
> + * Return: 0 on success, -errno on failure.
> + */
> +struct vdpa_device_attach_iommufd_as {
> +       __u32 argsz;
> +       __u32 flags;
> +       __u32 ioas_id;
> +};

I think we need to map ioas to vDPA AS, so there should be an ASID
from the view of vDPA?

Thanks

> +
> +#define VDPA_DEVICE_ATTACH_IOMMUFD_AS \
> +       _IOW(VHOST_VIRTIO, 0x82, struct vdpa_device_attach_iommufd_as)
> +
> +/*
> + * VDPA_DEVICE_DETACH_IOMMUFD_AS
> + *
> + * Detach a vdpa device from the iommufd address space it has been
> + * attached to. After it, device should be in a blocking DMA state.
> + *
> + * Available only after a device has been bound to iommufd via
> + * VHOST_VDPA_SET_IOMMU_FD
> + *
> + * @argsz:     user filled size of this data.
> + * @flags:     must be 0.
> + *
> + * Return: 0 on success, -errno on failure.
> + */
> +struct vdpa_device_detach_iommufd_as {
> +       __u32 argsz;
> +       __u32 flags;
> +};
> +
> +#define VDPA_DEVICE_DETACH_IOMMUFD_AS \
> +       _IOW(VHOST_VIRTIO, 0x83, struct vdpa_device_detach_iommufd_as)
> +
>  #endif
> --
> 2.34.3
>