RE: [RFC PATCH v2 3/3] RDMA/uverbs: Add uverbs command for dma-buf based MR registration

["Xiong, Jianxin" <jianxin.xiong@intel.com>]

Cc'd drm people.

> -----Original Message-----
> From: Xiong, Jianxin <jianxin.xiong@intel.com>
> Sent: Monday, June 29, 2020 10:32 AM
> To: linux-rdma@vger.kernel.org
> Cc: Xiong, Jianxin <jianxin.xiong@intel.com>; Doug Ledford <dledford@redhat.com>; Jason Gunthorpe <jgg@ziepe.ca>; Sumit Semwal
> <sumit.semwal@linaro.org>; Leon Romanovsky <leon@kernel.org>; Vetter, Daniel <daniel.vetter@intel.com>
> Subject: [RFC PATCH v2 3/3] RDMA/uverbs: Add uverbs command for dma-buf based MR registration
> 
> Add uverbs command for registering user memory region associated with a dma-buf file descriptor.
> 
> Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> Reviewed-by: Sean Hefty <sean.hefty@intel.com>
> Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> ---
>  drivers/infiniband/core/uverbs_std_types_mr.c | 112 ++++++++++++++++++++++++++
>  include/uapi/rdma/ib_user_ioctl_cmds.h        |  14 ++++
>  2 files changed, 126 insertions(+)
> 
> diff --git a/drivers/infiniband/core/uverbs_std_types_mr.c b/drivers/infiniband/core/uverbs_std_types_mr.c
> index c1286a5..2c9ff7c 100644
> --- a/drivers/infiniband/core/uverbs_std_types_mr.c
> +++ b/drivers/infiniband/core/uverbs_std_types_mr.c
> @@ -1,5 +1,6 @@
>  /*
>   * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
> + * Copyright (c) 2020, Intel Corporation.  All rights reserved.
>   *
>   * This software is available to you under a choice of one of two
>   * licenses.  You may choose to be licensed under the terms of the GNU @@ -154,6 +155,85 @@ static int
> UVERBS_HANDLER(UVERBS_METHOD_DM_MR_REG)(
>  	return ret;
>  }
> 
> +static int UVERBS_HANDLER(UVERBS_METHOD_REG_DMABUF_MR)(
> +	struct uverbs_attr_bundle *attrs)
> +{
> +	struct ib_uobject *uobj =
> +		uverbs_attr_get_uobject(attrs, UVERBS_ATTR_REG_DMABUF_MR_HANDLE);
> +	struct ib_pd *pd =
> +		uverbs_attr_get_obj(attrs, UVERBS_ATTR_REG_DMABUF_MR_PD_HANDLE);
> +	struct ib_device *ib_dev = pd->device;
> +
> +	u64 addr, length, hca_va;
> +	u32 fd;
> +	u32 access_flags;
> +	struct ib_mr *mr;
> +	int ret;
> +
> +	if (!ib_dev->ops.reg_user_mr)
> +		return -EOPNOTSUPP;
> +
> +	ret = uverbs_copy_from(&addr, attrs, UVERBS_ATTR_REG_DMABUF_MR_ADDR);
> +	if (ret)
> +		return ret;
> +
> +	ret = uverbs_copy_from(&length, attrs,
> +			       UVERBS_ATTR_REG_DMABUF_MR_LENGTH);
> +	if (ret)
> +		return ret;
> +
> +	ret = uverbs_copy_from(&hca_va, attrs,
> +			       UVERBS_ATTR_REG_DMABUF_MR_HCA_VA);
> +	if (ret)
> +		return ret;
> +
> +	ret = uverbs_copy_from(&fd, attrs,
> +			       UVERBS_ATTR_REG_DMABUF_MR_FD);
> +	if (ret)
> +		return ret;
> +
> +	ret = uverbs_get_flags32(&access_flags, attrs,
> +				 UVERBS_ATTR_REG_DMABUF_MR_ACCESS_FLAGS,
> +				 IB_ACCESS_SUPPORTED);
> +	if (ret)
> +		return ret;
> +
> +	ret = ib_check_mr_access(access_flags);
> +	if (ret)
> +		return ret;
> +
> +	mr = pd->device->ops.reg_user_mr(pd, addr, length, hca_va,
> +					   (int)(s32)fd, access_flags,
> +					   &attrs->driver_udata);
> +	if (IS_ERR(mr))
> +		return PTR_ERR(mr);
> +
> +	mr->device  = pd->device;
> +	mr->pd      = pd;
> +	mr->type    = IB_MR_TYPE_USER;
> +	mr->uobject = uobj;
> +	atomic_inc(&pd->usecnt);
> +
> +	uobj->object = mr;
> +
> +	ret = uverbs_copy_to(attrs, UVERBS_ATTR_REG_DMABUF_MR_RESP_LKEY,
> +			     &mr->lkey, sizeof(mr->lkey));
> +	if (ret)
> +		goto err_dereg;
> +
> +	ret = uverbs_copy_to(attrs, UVERBS_ATTR_REG_DMABUF_MR_RESP_RKEY,
> +			     &mr->rkey, sizeof(mr->rkey));
> +	if (ret)
> +		goto err_dereg;
> +
> +	return 0;
> +
> +err_dereg:
> +	ib_dereg_mr_user(mr, uverbs_get_cleared_udata(attrs));
> +
> +	return ret;
> +}
> +
>  DECLARE_UVERBS_NAMED_METHOD(
>  	UVERBS_METHOD_ADVISE_MR,
>  	UVERBS_ATTR_IDR(UVERBS_ATTR_ADVISE_MR_PD_HANDLE,
> @@ -200,6 +280,37 @@ static int UVERBS_HANDLER(UVERBS_METHOD_DM_MR_REG)(
>  			    UVERBS_ATTR_TYPE(u32),
>  			    UA_MANDATORY));
> 
> +DECLARE_UVERBS_NAMED_METHOD(
> +	UVERBS_METHOD_REG_DMABUF_MR,
> +	UVERBS_ATTR_IDR(UVERBS_ATTR_REG_DMABUF_MR_HANDLE,
> +			UVERBS_OBJECT_MR,
> +			UVERBS_ACCESS_NEW,
> +			UA_MANDATORY),
> +	UVERBS_ATTR_IDR(UVERBS_ATTR_REG_DMABUF_MR_PD_HANDLE,
> +			UVERBS_OBJECT_PD,
> +			UVERBS_ACCESS_READ,
> +			UA_MANDATORY),
> +	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_ADDR,
> +			   UVERBS_ATTR_TYPE(u64),
> +			   UA_MANDATORY),
> +	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_LENGTH,
> +			   UVERBS_ATTR_TYPE(u64),
> +			   UA_MANDATORY),
> +	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_HCA_VA,
> +			   UVERBS_ATTR_TYPE(u64),
> +			   UA_MANDATORY),
> +	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_REG_DMABUF_MR_FD,
> +			   UVERBS_ATTR_TYPE(u32),
> +			   UA_MANDATORY),
> +	UVERBS_ATTR_FLAGS_IN(UVERBS_ATTR_REG_DMABUF_MR_ACCESS_FLAGS,
> +			     enum ib_access_flags),
> +	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_REG_DMABUF_MR_RESP_LKEY,
> +			    UVERBS_ATTR_TYPE(u32),
> +			    UA_MANDATORY),
> +	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_REG_DMABUF_MR_RESP_RKEY,
> +			    UVERBS_ATTR_TYPE(u32),
> +			    UA_MANDATORY));
> +
>  DECLARE_UVERBS_NAMED_METHOD_DESTROY(
>  	UVERBS_METHOD_MR_DESTROY,
>  	UVERBS_ATTR_IDR(UVERBS_ATTR_DESTROY_MR_HANDLE,
> @@ -210,6 +321,7 @@ static int UVERBS_HANDLER(UVERBS_METHOD_DM_MR_REG)(
>  DECLARE_UVERBS_NAMED_OBJECT(
>  	UVERBS_OBJECT_MR,
>  	UVERBS_TYPE_ALLOC_IDR(uverbs_free_mr),
> +	&UVERBS_METHOD(UVERBS_METHOD_REG_DMABUF_MR),
>  	&UVERBS_METHOD(UVERBS_METHOD_DM_MR_REG),
>  	&UVERBS_METHOD(UVERBS_METHOD_MR_DESTROY),
>  	&UVERBS_METHOD(UVERBS_METHOD_ADVISE_MR));
> diff --git a/include/uapi/rdma/ib_user_ioctl_cmds.h b/include/uapi/rdma/ib_user_ioctl_cmds.h
> index d4ddbe4..31aacbf 100644
> --- a/include/uapi/rdma/ib_user_ioctl_cmds.h
> +++ b/include/uapi/rdma/ib_user_ioctl_cmds.h
> @@ -1,5 +1,6 @@
>  /*
>   * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
> + * Copyright (c) 2020, Intel Corporation. All rights reserved.
>   *
>   * This software is available to you under a choice of one of two
>   * licenses.  You may choose to be licensed under the terms of the GNU @@ -161,6 +162,7 @@ enum uverbs_methods_mr {
>  	UVERBS_METHOD_DM_MR_REG,
>  	UVERBS_METHOD_MR_DESTROY,
>  	UVERBS_METHOD_ADVISE_MR,
> +	UVERBS_METHOD_REG_DMABUF_MR,
>  };
> 
>  enum uverbs_attrs_mr_destroy_ids {
> @@ -174,6 +176,18 @@ enum uverbs_attrs_advise_mr_cmd_attr_ids {
>  	UVERBS_ATTR_ADVISE_MR_SGE_LIST,
>  };
> 
> +enum uverbs_attrs_reg_dmabuf_mr_cmd_attr_ids {
> +	UVERBS_ATTR_REG_DMABUF_MR_HANDLE,
> +	UVERBS_ATTR_REG_DMABUF_MR_PD_HANDLE,
> +	UVERBS_ATTR_REG_DMABUF_MR_ADDR,
> +	UVERBS_ATTR_REG_DMABUF_MR_LENGTH,
> +	UVERBS_ATTR_REG_DMABUF_MR_HCA_VA,
> +	UVERBS_ATTR_REG_DMABUF_MR_FD,
> +	UVERBS_ATTR_REG_DMABUF_MR_ACCESS_FLAGS,
> +	UVERBS_ATTR_REG_DMABUF_MR_RESP_LKEY,
> +	UVERBS_ATTR_REG_DMABUF_MR_RESP_RKEY,
> +};
> +
>  enum uverbs_attrs_create_counters_cmd_attr_ids {
>  	UVERBS_ATTR_CREATE_COUNTERS_HANDLE,
>  };
> --
> 1.8.3.1