Re: [PATCH v3 04/10] net/ice/base: set speculative execution barrier

[Bruce Richardson <bruce.richardson@intel.com>]

On Tue, May 27, 2025 at 01:17:23PM +0000, Dhanya Pillai wrote:
> From: Lukasz Krakowiak <lukaszx.krakowiak@intel.com>
> 
> Fix issues related to SPECULATIVE_EXECUTION_DATA_LEAK.
> This changes set speculative execution barrier to functions:
> 
> * ice_sched_add_vsi_child_nodes,
> * ice_sched_add_vsi_support_nodes,
> * ice_sched_move_vsi_to_agg,
> * ice_prof_has_mask_idx,
> * ice_alloc_prof_mask.
> 
> Also, Added memfence definitions.
> 
> Signed-off-by: Lukasz Krakowiak <lukaszx.krakowiak@intel.com>
> Signed-off-by: Dhanya Pillai <dhanya.r.pillai@intel.com>
> ---
>  drivers/net/intel/ice/base/ice_flex_pipe.c | 2 ++
>  drivers/net/intel/ice/base/ice_osdep.h     | 6 ++++++
>  drivers/net/intel/ice/base/ice_sched.c     | 3 +++
>  3 files changed, 11 insertions(+)
> 
> diff --git a/drivers/net/intel/ice/base/ice_flex_pipe.c b/drivers/net/intel/ice/base/ice_flex_pipe.c
> index 6dd5588f85..dc8c92e203 100644
> --- a/drivers/net/intel/ice/base/ice_flex_pipe.c
> +++ b/drivers/net/intel/ice/base/ice_flex_pipe.c
> @@ -1280,6 +1280,7 @@ ice_prof_has_mask_idx(struct ice_hw *hw, enum ice_block blk, u8 prof, u16 idx,
>  			if (hw->blk[blk].masks.masks[i].in_use &&
>  			    hw->blk[blk].masks.masks[i].idx == idx) {
>  				found = true;
> +				ice_memfence_read();
>  				if (hw->blk[blk].masks.masks[i].mask == mask)
>  					match = true;
>  				break;
> @@ -1648,6 +1649,7 @@ ice_alloc_prof_mask(struct ice_hw *hw, enum ice_block blk, u16 idx, u16 mask,
>  			/* if mask is in use and it exactly duplicates the
>  			 * desired mask and index, then in can be reused
>  			 */
> +			ice_memfence_read();
>  			if (hw->blk[blk].masks.masks[i].mask == mask &&
>  			    hw->blk[blk].masks.masks[i].idx == idx) {
>  				found_copy = true;
> diff --git a/drivers/net/intel/ice/base/ice_osdep.h b/drivers/net/intel/ice/base/ice_osdep.h
> index ad6cde9896..7588ad3dbc 100644
> --- a/drivers/net/intel/ice/base/ice_osdep.h
> +++ b/drivers/net/intel/ice/base/ice_osdep.h
> @@ -203,6 +203,12 @@ struct __rte_packed_begin ice_virt_mem {
>  #define ice_memset(a, b, c, d) memset((a), (b), (c))
>  #define ice_memcpy(a, b, c, d) rte_memcpy((a), (b), (c))
>  
> +/* Memory fence barrier */
> +#define ice_memfence_read()
> +#define ice_memfence_read_write()
> +#define ice_memfence_write()
> +

I suspect rather than removing this, they would be better defined as
rte_smp_* barriers. As in:

#define ice_memfence_read() rte_smp_rmb()

Let me know if you agree with this proposal, and I'll add it on apply.

/Bruce