RE: [PATCH v1 08/13] test/bbdev: extend support for large TB

["Vargas, Hernan" <hernan.vargas@intel.com>]

Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Tuesday, January 31, 2023 5:29 AM
> To: Vargas, Hernan <hernan.vargas@intel.com>; dev@dpdk.org;
> gakhil@marvell.com; Rix, Tom <trix@redhat.com>
> Cc: Chautru, Nicolas <nicolas.chautru@intel.com>; Zhang, Qi Z
> <qi.z.zhang@intel.com>
> Subject: Re: [PATCH v1 08/13] test/bbdev: extend support for large TB
> 
> 
> 
> On 1/17/23 17:50, Hernan Vargas wrote:
> > Add support for large TB when it cannot fit into a true mbuf.
> >
> > Signed-off-by: Hernan Vargas <hernan.vargas@intel.com>
> > ---
> >   app/test-bbdev/test_bbdev_perf.c | 21 ++++++++++++---------
> >   1 file changed, 12 insertions(+), 9 deletions(-)
> >
> > diff --git a/app/test-bbdev/test_bbdev_perf.c
> > b/app/test-bbdev/test_bbdev_perf.c
> > index 69b86cdeb1..fdf7a28ba2 100644
> > --- a/app/test-bbdev/test_bbdev_perf.c
> > +++ b/app/test-bbdev/test_bbdev_perf.c
> > @@ -1072,8 +1072,6 @@ init_op_data_objs(struct rte_bbdev_op_data
> *bufs,
> >   			 * Special case when DPDK mbuf cannot handle
> >   			 * the required input size
> >   			 */
> > -			printf("Warning: Larger input size than DPDK mbuf
> %d\n",
> > -					seg->length);
> >   			large_input = true;
> >   		}
> >   		bufs[i].data = m_head;
> > @@ -2030,6 +2028,7 @@ validate_op_chain(struct rte_bbdev_op_data
> *op,
> >   	struct rte_mbuf *m = op->data;
> >   	uint8_t nb_dst_segments = orig_op->nb_segments;
> >   	uint32_t total_data_size = 0;
> > +	bool ignore_mbuf = false; /* ignore mbuf limitations */
> >
> >   	TEST_ASSERT(nb_dst_segments == m->nb_segs,
> >   			"Number of segments differ in original (%u) and filled
> (%u) op",
> > @@ -2042,21 +2041,25 @@ validate_op_chain(struct rte_bbdev_op_data
> *op,
> >   		uint16_t data_len = rte_pktmbuf_data_len(m) - offset;
> >   		total_data_size += orig_op->segments[i].length;
> >
> > -		TEST_ASSERT(orig_op->segments[i].length == data_len,
> > -				"Length of segment differ in original (%u) and
> filled (%u) op",
> > -				orig_op->segments[i].length, data_len);
> > +		if (orig_op->segments[i].length >
> RTE_BBDEV_LDPC_E_MAX_MBUF)
> > +			ignore_mbuf = true;
> > +		if (!ignore_mbuf)
> > +			TEST_ASSERT(orig_op->segments[i].length ==
> data_len,
> > +					"Length of segment differ in original
> (%u) and filled (%u) op",
> > +					orig_op->segments[i].length,
> data_len);
> >   		TEST_ASSERT_BUFFERS_ARE_EQUAL(orig_op-
> >segments[i].addr,
> >   				rte_pktmbuf_mtod_offset(m, uint32_t *,
> offset),
> > -				data_len,
> > +				orig_op->segments[i].length,
> 
> Isn't it ending up in performing out of bounds access in the mbuf?

No, in the case when ignore_mbuf is set to true, we use a "fake" mbuf allocated in memory with rte_malloc.
The size allocated is segments[i].length.
Thanks

> >   				"Output buffers (CB=%u) are not equal", i);
> >   		m = m->next;
> >   	}
> >
> >   	/* Validate total mbuf pkt length */
> >   	uint32_t pkt_len = rte_pktmbuf_pkt_len(op->data) - op->offset;
> > -	TEST_ASSERT(total_data_size == pkt_len,
> > -			"Length of data differ in original (%u) and filled (%u)
> op",
> > -			total_data_size, pkt_len);
> > +	if (!ignore_mbuf)
> > +		TEST_ASSERT(total_data_size == pkt_len,
> > +				"Length of data differ in original (%u) and
> filled (%u) op",
> > +				total_data_size, pkt_len);
> >
> >   	return TEST_SUCCESS;
> >   }