Re: [PATCH v2] IB/mlx5: Fix binary compatibility with libmlx5

[Yann Droneaud <ydroneaud-RlY5vtjFyJ3QT0dZR+AlfA@public.gmane.org>]

Hi,

Le jeudi 30 janvier 2014 à 13:49 +0200, Eli Cohen a écrit :
> Commit c1be5232d21d "Fix micro UAR allocator" broke binary compatibility
> between libmlx5 and mlx5_ib since it defines a different value to the number of
> micro UARs per page, leading to wrong calculation in libmlx5. This patch
> defines struct mlx5_ib_alloc_ucontext_req_v2 as an extension to struct
> mlx5_ib_alloc_ucontext_req.  The extended size is determined in
> mlx5_ib_alloc_ucontext() and in case of old library we use uuarn 0 which works
> fine -- this is acheived due to create_user_qp() falling back from high to
> medium then to low class where low class will return 0. For new libraries we
> use the more sophisticated allocation algorithm.
> 
> Fixes: c1be5232d21d ('Fix micro UAR allocator')
> Signed-off-by: Eli Cohen <eli-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

Reviewed-by: Yann Droneaud <ydroneaud-RlY5vtjFyJ3QT0dZR+AlfA@public.gmane.org>

> ---
> Changes from v1:
> Use 12 digit hash code as required
> Fix mlx5_ib_alloc_ucontext to subtract the size of struct ib_uverbs_cmd_hdr)
> Improve change log documentation
> Remove whitesapce
> 

Thanks.

>  drivers/infiniband/hw/mlx5/main.c | 19 +++++++++++++++++--
>  drivers/infiniband/hw/mlx5/qp.c   | 10 ++++++++--
>  drivers/infiniband/hw/mlx5/user.h |  7 +++++++
>  include/linux/mlx5/driver.h       |  1 +
>  4 files changed, 33 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
> index 9660d093f8cf..f4ef4a24d410 100644
> --- a/drivers/infiniband/hw/mlx5/main.c
> +++ b/drivers/infiniband/hw/mlx5/main.c
> @@ -536,24 +536,38 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev,
>  						  struct ib_udata *udata)
>  {
>  	struct mlx5_ib_dev *dev = to_mdev(ibdev);
> -	struct mlx5_ib_alloc_ucontext_req req;
> +	struct mlx5_ib_alloc_ucontext_req_v2 req;
>  	struct mlx5_ib_alloc_ucontext_resp resp;
>  	struct mlx5_ib_ucontext *context;
>  	struct mlx5_uuar_info *uuari;
>  	struct mlx5_uar *uars;
>  	int gross_uuars;
>  	int num_uars;
> +	int ver;
>  	int uuarn;
>  	int err;
>  	int i;
> +	int reqlen;
>  
>  	if (!dev->ib_active)
>  		return ERR_PTR(-EAGAIN);
>  
> -	err = ib_copy_from_udata(&req, udata, sizeof(req));
> +	memset(&req, 0, sizeof(req));
> +	reqlen = udata->inlen - sizeof(struct ib_uverbs_cmd_hdr);
> +	if (reqlen == sizeof(struct mlx5_ib_alloc_ucontext_req))
> +		ver = 0;
> +	else if (reqlen == sizeof(struct mlx5_ib_alloc_ucontext_req_v2))
> +		ver = 2;
> +	else
> +		return ERR_PTR(-EINVAL);
> +
> +	err = ib_copy_from_udata(&req, udata, reqlen);
>  	if (err)
>  		return ERR_PTR(err);
>  
> +	if (req.flags || req.reserved)
> +		return ERR_PTR(-EINVAL);
> +
>  	if (req.total_num_uuars > MLX5_MAX_UUARS)
>  		return ERR_PTR(-ENOMEM);
>  
> @@ -626,6 +640,7 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev,
>  	if (err)
>  		goto out_uars;
>  
> +	uuari->ver = ver;
>  	uuari->num_low_latency_uuars = req.num_low_latency_uuars;
>  	uuari->uars = uars;
>  	uuari->num_uars = num_uars;
> diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
> index 492dc330e907..091576a777e9 100644
> --- a/drivers/infiniband/hw/mlx5/qp.c
> +++ b/drivers/infiniband/hw/mlx5/qp.c
> @@ -430,11 +430,17 @@ static int alloc_uuar(struct mlx5_uuar_info *uuari,
>  		break;
>  
>  	case MLX5_IB_LATENCY_CLASS_MEDIUM:
> -		uuarn = alloc_med_class_uuar(uuari);
> +		if (uuari->ver < 2)
> +			uuarn = -ENOMEM;
> +		else
> +			uuarn = alloc_med_class_uuar(uuari);
>  		break;
>  
>  	case MLX5_IB_LATENCY_CLASS_HIGH:
> -		uuarn = alloc_high_class_uuar(uuari);
> +		if (uuari->ver < 2)
> +			uuarn = -ENOMEM;
> +		else
> +			uuarn = alloc_high_class_uuar(uuari);
>  		break;
>  
>  	case MLX5_IB_LATENCY_CLASS_FAST_PATH:
> diff --git a/drivers/infiniband/hw/mlx5/user.h b/drivers/infiniband/hw/mlx5/user.h
> index 32a2a5dfc523..0f4f8e42a17f 100644
> --- a/drivers/infiniband/hw/mlx5/user.h
> +++ b/drivers/infiniband/hw/mlx5/user.h
> @@ -62,6 +62,13 @@ struct mlx5_ib_alloc_ucontext_req {
>  	__u32	num_low_latency_uuars;
>  };
>  
> +struct mlx5_ib_alloc_ucontext_req_v2 {
> +	__u32	total_num_uuars;
> +	__u32	num_low_latency_uuars;
> +	__u32	flags;
> +	__u32	reserved;
> +};
> +
>  struct mlx5_ib_alloc_ucontext_resp {
>  	__u32	qp_tab_size;
>  	__u32	bf_reg_size;
> diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
> index 554548cd3dd4..32cb18c399c2 100644
> --- a/include/linux/mlx5/driver.h
> +++ b/include/linux/mlx5/driver.h
> @@ -227,6 +227,7 @@ struct mlx5_uuar_info {
>  	 * protect uuar allocation data structs
>  	 */
>  	struct mutex		lock;
> +	u32			ver;
>  };
>  
>  struct mlx5_bf {

-- 
Yann Droneaud
OPTEYA


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