Re: [PATCH v1] dmaengine: idxd: Narrow the restriction on BATCH to ver. 1 only

[Dave Jiang <dave.jiang@intel.com>]

On 3/12/25 3:15 PM, Vinicius Costa Gomes wrote:
> Allow BATCH operations to be submitted and the capability to be
> exposed for DSA version 2 (or later) devices.
> 
> DSA version 2 devices allow safe submission of BATCH operations.
> 
> Signed-off-by: Anil Keshavamurthy <anil.s.keshavamurthy@intel.com>
> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/dma/idxd/cdev.c  | 6 ++++--
>  drivers/dma/idxd/sysfs.c | 6 ++++--
>  2 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
> index ff94ee892339..6a1dc15ee485 100644
> --- a/drivers/dma/idxd/cdev.c
> +++ b/drivers/dma/idxd/cdev.c
> @@ -439,10 +439,12 @@ static int idxd_submit_user_descriptor(struct idxd_user_context *ctx,
>  	 * DSA devices are capable of indirect ("batch") command submission.
>  	 * On devices where direct user submissions are not safe, we cannot
>  	 * allow this since there is no good way for us to verify these
> -	 * indirect commands.
> +	 * indirect commands. Narrow the restriction of operations with the
> +	 * BATCH opcode to only DSA version 1 devices.
>  	 */
>  	if (is_dsa_dev(idxd_dev) && descriptor.opcode == DSA_OPCODE_BATCH &&
> -		!wq->idxd->user_submission_safe)
> +	    wq->idxd->hw.version == DEVICE_VERSION_1 &&
> +	    !wq->idxd->user_submission_safe)
>  		return -EINVAL;
>  	/*
>  	 * As per the programming specification, the completion address must be
> diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
> index 6af493f6ba77..9f0701021af0 100644
> --- a/drivers/dma/idxd/sysfs.c
> +++ b/drivers/dma/idxd/sysfs.c
> @@ -1208,9 +1208,11 @@ static ssize_t op_cap_show_common(struct device *dev, char *buf, unsigned long *
>  
>  		/* On systems where direct user submissions are not safe, we need to clear out
>  		 * the BATCH capability from the capability mask in sysfs since we cannot support
> -		 * that command on such systems.
> +		 * that command on such systems. Narrow the restriction of operations with the
> +		 * BATCH opcode to only DSA version 1 devices.
>  		 */
> -		if (i == DSA_OPCODE_BATCH/64 && !confdev_to_idxd(dev)->user_submission_safe)
> +		if (i == DSA_OPCODE_BATCH/64 && !confdev_to_idxd(dev)->user_submission_safe &&
> +		    confdev_to_idxd(dev)->hw.version == DEVICE_VERSION_1)
>  			clear_bit(DSA_OPCODE_BATCH % 64, &val);
>  
>  		pos += sysfs_emit_at(buf, pos, "%*pb", 64, &val);