[v2] net/mlx5: fix split buffer Rx
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Commit Message
Routine to lookup LKey on Rx was assuming that the mbuf address
always belongs to a single mempool: the one associated with an RxQ
or the MPRQ mempool. This assumption is false for split buffers case.
A wrong LKey was looked up, resulting in completion errors.
Modify lookup routines to lookup LKey in the mbuf->pool
for non-MPRQ cases both on Rx datapath and on queue initialization.
Fixes: fec28ca0e3a9 ("net/mlx5: support mempool registration")
Signed-off-by: Dmitry Kozlyuk <dkozlyuk@nvidia.com>
Reviewed-by: Matan Azrad <matan@nvidia.com>
Reviewed-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
---
v2: rebase on next-net-mlx
drivers/net/mlx5/mlx5_rx.c | 5 ++++-
drivers/net/mlx5/mlx5_rx.h | 37 +++++++++++++++++++++++++++++++++++--
2 files changed, 39 insertions(+), 3 deletions(-)
Comments
Hi,
> -----Original Message-----
> From: Dmitry Kozlyuk <dkozlyuk@nvidia.com>
> Sent: Monday, November 8, 2021 1:17 PM
> To: dev@dpdk.org
> Cc: Raslan Darawsheh <rasland@nvidia.com>; Matan Azrad
> <matan@nvidia.com>; Slava Ovsiienko <viacheslavo@nvidia.com>
> Subject: [PATCH v2] net/mlx5: fix split buffer Rx
>
> Routine to lookup LKey on Rx was assuming that the mbuf address always
> belongs to a single mempool: the one associated with an RxQ or the MPRQ
> mempool. This assumption is false for split buffers case.
> A wrong LKey was looked up, resulting in completion errors.
> Modify lookup routines to lookup LKey in the mbuf->pool for non-MPRQ
> cases both on Rx datapath and on queue initialization.
>
> Fixes: fec28ca0e3a9 ("net/mlx5: support mempool registration")
>
> Signed-off-by: Dmitry Kozlyuk <dkozlyuk@nvidia.com>
> Reviewed-by: Matan Azrad <matan@nvidia.com>
> Reviewed-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> ---
> v2: rebase on next-net-mlx
>
Patch applied to next-net-mlx,
Kindest regards,
Raslan Darawsheh
@@ -347,6 +347,7 @@ mlx5_rxq_initialize(struct mlx5_rxq_data *rxq)
volatile struct mlx5_wqe_data_seg *scat;
uintptr_t addr;
uint32_t byte_count;
+ uint32_t lkey;
if (mlx5_rxq_mprq_enabled(rxq)) {
struct mlx5_mprq_buf *buf = (*rxq->mprq_bufs)[i];
@@ -357,6 +358,7 @@ mlx5_rxq_initialize(struct mlx5_rxq_data *rxq)
1 << rxq->strd_num_n);
byte_count = (1 << rxq->strd_sz_n) *
(1 << rxq->strd_num_n);
+ lkey = mlx5_rx_addr2mr(rxq, addr);
} else {
struct rte_mbuf *buf = (*rxq->elts)[i];
@@ -364,13 +366,14 @@ mlx5_rxq_initialize(struct mlx5_rxq_data *rxq)
rxq->wqes)[i];
addr = rte_pktmbuf_mtod(buf, uintptr_t);
byte_count = DATA_LEN(buf);
+ lkey = mlx5_rx_mb2mr(rxq, buf);
}
/* scat->addr must be able to store a pointer. */
MLX5_ASSERT(sizeof(scat->addr) >= sizeof(uintptr_t));
*scat = (struct mlx5_wqe_data_seg){
.addr = rte_cpu_to_be_64(addr),
.byte_count = rte_cpu_to_be_32(byte_count),
- .lkey = mlx5_rx_addr2mr(rxq, addr),
+ .lkey = lkey,
};
}
rxq->consumed_strd = 0;
@@ -291,7 +291,7 @@ uint16_t mlx5_rx_burst_mprq_vec(void *dpdk_rxq, struct rte_mbuf **pkts,
static int mlx5_rxq_mprq_enabled(struct mlx5_rxq_data *rxq);
/**
- * Query LKey from a packet buffer for Rx. No need to flush local caches
+ * Query LKey for an address on Rx. No need to flush local caches
* as the Rx mempool database entries are valid for the lifetime of the queue.
*
* @param rxq
@@ -320,7 +320,40 @@ mlx5_rx_addr2mr(struct mlx5_rxq_data *rxq, uintptr_t addr)
mp, addr);
}
-#define mlx5_rx_mb2mr(rxq, mb) mlx5_rx_addr2mr(rxq, (uintptr_t)((mb)->buf_addr))
+/**
+ * Query LKey from a packet buffer for Rx. No need to flush local caches
+ * as the Rx mempool database entries are valid for the lifetime of the queue.
+ *
+ * @param rxq
+ * Pointer to Rx queue structure.
+ * @param mb
+ * Buffer to search the address of.
+ *
+ * @return
+ * Searched LKey on success, UINT32_MAX on no match.
+ * This function always succeeds on valid input.
+ */
+static __rte_always_inline uint32_t
+mlx5_rx_mb2mr(struct mlx5_rxq_data *rxq, struct rte_mbuf *mb)
+{
+ struct mlx5_mr_ctrl *mr_ctrl = &rxq->mr_ctrl;
+ uintptr_t addr = (uintptr_t)mb->buf_addr;
+ struct mlx5_rxq_ctrl *rxq_ctrl;
+ uint32_t lkey;
+
+ /* Linear search on MR cache array. */
+ lkey = mlx5_mr_lookup_lkey(mr_ctrl->cache, &mr_ctrl->mru,
+ MLX5_MR_CACHE_N, addr);
+ if (likely(lkey != UINT32_MAX))
+ return lkey;
+ /*
+ * Slower search in the mempool database on miss.
+ * During queue creation rxq->sh is not yet set, so we use rxq_ctrl.
+ */
+ rxq_ctrl = container_of(rxq, struct mlx5_rxq_ctrl, rxq);
+ return mlx5_mr_mempool2mr_bh(&rxq_ctrl->sh->cdev->mr_scache,
+ mr_ctrl, mb->pool, addr);
+}
/**
* Convert timestamp from HW format to linear counter