Re: [dpdk-dev] [PATCH] app/testpmd: fix RSS key

["Zhang, AlvinX" <alvinx.zhang@intel.com>]

Hi Ferruh,

Thanks for your review.
I will modify the patch in V2.

Alvin

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Wednesday, January 20, 2021 3:15 AM
> To: Zhang, AlvinX <alvinx.zhang@intel.com>
> Cc: dev@dpdk.org; stable@dpdk.org
> Subject: Re: [PATCH] app/testpmd: fix RSS key
> 
> On 1/18/2021 8:59 AM, Zhang,Alvin wrote:
> > From: Alvin Zhang <alvinx.zhang@intel.com>
> >
> > Since the patch '1848b117' has set the value of key in 'struct
> > rte_flow_action_rss' to NULL, the PMD cannot get the RSS key now.
> >
> > This patch sets offset and size of the key pointer as the first
> > parameter of the token 'key' and copies the start address of the 'HEX'
> > data to the location specified by the first parameter of the token.
> >
> 
> Can you please put the rte_flow command that enables reproducing this defect,
> it may help in the future?
> 
> > Fixes: 1848b117cca1 ("app/testpmd: fix RSS key for flow API RSS rule")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Alvin Zhang <alvinx.zhang@intel.com>
> > ---
> >   app/test-pmd/cmdline_flow.c | 24 +++++++++++++-----------
> >   1 file changed, 13 insertions(+), 11 deletions(-)
> >
> > diff --git a/app/test-pmd/cmdline_flow.c b/app/test-pmd/cmdline_flow.c
> > index 585cab9..6eb46d3 100644
> > --- a/app/test-pmd/cmdline_flow.c
> > +++ b/app/test-pmd/cmdline_flow.c
> > @@ -3403,7 +3403,10 @@ static int comp_set_sample_index(struct context
> *, const struct token *,
> >   		.name = "key",
> >   		.help = "RSS hash key",
> >   		.next = NEXT(action_rss, NEXT_ENTRY(HEX)),
> > -		.args = ARGS(ARGS_ENTRY_ARB(0, 0),
> > +		.args = ARGS(ARGS_ENTRY_ARB
> > +			     (offsetof(struct action_rss_data, conf) +
> > +			      offsetof(struct rte_flow_action_rss, key),
> > +			      sizeof(((struct rte_flow_action_rss *)0)->key)),
> 
> 
> +1, it is required to write the address, and I confirm this enables
> +getting
> 'key' value to the PMD.
> 
> >   			     ARGS_ENTRY_ARB
> >   			     (offsetof(struct action_rss_data, conf) +
> >   			      offsetof(struct rte_flow_action_rss, key_len), @@
> -6495,19
> > +6498,18 @@ static int comp_set_sample_index(struct context *, const
> struct token *,
> >   	if (ctx->objmask)
> >   		memset((uint8_t *)ctx->objmask + arg_data->offset,
> >   					0xff, hexlen);
> > +
> >   	/* Save address if requested. */
> >   	if (arg_addr->size) {
> > -		memcpy((uint8_t *)ctx->object + arg_addr->offset,
> > -		       (void *[]){
> > -			(uint8_t *)ctx->object + arg_data->offset
> > -		       },
> > -		       arg_addr->size);
> > +		if (arg_addr->size < sizeof(void *))
> > +			goto error;
> 
> Above two lines seems only actual change in this function, others are refactoring
> the assignment.
> 
> 1) why this check required, I think we can ignore it.
> 2) What do you think to remove the refactoring to reduce the change to the
> actual fix?
> 
> > +
> > +		*(void **)((uint8_t *)ctx->object + arg_addr->offset) =
> > +				(uint8_t *)ctx->object + arg_data->offset;
> > +
> >   		if (ctx->objmask)
> > -			memcpy((uint8_t *)ctx->objmask + arg_addr->offset,
> > -			       (void *[]){
> > -				(uint8_t *)ctx->objmask + arg_data->offset
> > -			       },
> > -			       arg_addr->size);
> > +			*(void **)((uint8_t *)ctx->objmask + arg_addr->offset) =
> > +				(uint8_t *)ctx->objmask + arg_data->offset;
> >   	}
> >   	return len;
> >   error:
> >