net/virtio: fix memory leak when reinitializing device

[dpdk.git] / drivers / net / mlx4 / mlx4_mr.c

diff --git a/drivers/net/mlx4/mlx4_mr.c b/drivers/net/mlx4/mlx4_mr.c
index 8105cc5..2a3e269 100644 (file)
--- a/drivers/net/mlx4/mlx4_mr.c
+++ b/drivers/net/mlx4/mlx4_mr.c
@@ -55,8 +55,10 @@
 #include <rte_branch_prediction.h>
 #include <rte_common.h>
 #include <rte_errno.h>
+#include <rte_malloc.h>
 #include <rte_memory.h>
 #include <rte_mempool.h>
+#include <rte_spinlock.h>
 
 #include "mlx4_rxtx.h"
 #include "mlx4_utils.h"
@@ -135,24 +137,27 @@ mlx4_check_mempool(struct rte_mempool *mp, uintptr_t *start, uintptr_t *end)
 }
 
 /**
- * Register mempool as a memory region.
+ * Obtain a memory region from a memory pool.
  *
- * @param pd
- *   Pointer to protection domain.
+ * If a matching memory region already exists, it is returned with its
+ * reference count incremented, otherwise a new one is registered.
+ *
+ * @param priv
+ *   Pointer to private structure.
  * @param mp
  *   Pointer to memory pool.
  *
  * @return
  *   Memory region pointer, NULL in case of error and rte_errno is set.
  */
-struct ibv_mr *
-mlx4_mp2mr(struct ibv_pd *pd, struct rte_mempool *mp)
+struct mlx4_mr *
+mlx4_mr_get(struct priv *priv, struct rte_mempool *mp)
 {
        const struct rte_memseg *ms = rte_eal_get_physmem_layout();
        uintptr_t start;
        uintptr_t end;
        unsigned int i;
-       struct ibv_mr *mr;
+       struct mlx4_mr *mr;
 
        if (mlx4_check_mempool(mp, &start, &end) != 0) {
                rte_errno = EINVAL;
@@ -177,15 +182,70 @@ mlx4_mp2mr(struct ibv_pd *pd, struct rte_mempool *mp)
        DEBUG("mempool %p using start=%p end=%p size=%zu for MR",
              (void *)mp, (void *)start, (void *)end,
              (size_t)(end - start));
-       mr = ibv_reg_mr(pd,
-                       (void *)start,
-                       end - start,
-                       IBV_ACCESS_LOCAL_WRITE);
-       if (!mr)
+       rte_spinlock_lock(&priv->mr_lock);
+       LIST_FOREACH(mr, &priv->mr, next)
+               if (mp == mr->mp && start >= mr->start && end <= mr->end)
+                       break;
+       if (mr) {
+               ++mr->refcnt;
+               goto release;
+       }
+       mr = rte_malloc(__func__, sizeof(*mr), 0);
+       if (!mr) {
+               rte_errno = ENOMEM;
+               goto release;
+       }
+       *mr = (struct mlx4_mr){
+               .start = start,
+               .end = end,
+               .refcnt = 1,
+               .priv = priv,
+               .mr = ibv_reg_mr(priv->pd, (void *)start, end - start,
+                                IBV_ACCESS_LOCAL_WRITE),
+               .mp = mp,
+       };
+       if (mr->mr) {
+               mr->lkey = mr->mr->lkey;
+               LIST_INSERT_HEAD(&priv->mr, mr, next);
+       } else {
+               rte_free(mr);
+               mr = NULL;
                rte_errno = errno ? errno : EINVAL;
+       }
+release:
+       rte_spinlock_unlock(&priv->mr_lock);
        return mr;
 }
 
+/**
+ * Release a memory region.
+ *
+ * This function decrements its reference count and destroys it after
+ * reaching 0.
+ *
+ * Note to avoid race conditions given this function may be used from the
+ * data plane, it's extremely important that each user holds its own
+ * reference.
+ *
+ * @param mr
+ *   Memory region to release.
+ */
+void
+mlx4_mr_put(struct mlx4_mr *mr)
+{
+       struct priv *priv = mr->priv;
+
+       rte_spinlock_lock(&priv->mr_lock);
+       assert(mr->refcnt);
+       if (--mr->refcnt)
+               goto release;
+       LIST_REMOVE(mr, next);
+       claim_zero(ibv_dereg_mr(mr->mr));
+       rte_free(mr);
+release:
+       rte_spinlock_unlock(&priv->mr_lock);
+}
+
 /**
  * Add memory region (MR) <-> memory pool (MP) association to txq->mp2mr[].
  * If mp2mr[] is full, remove an entry first.
@@ -203,14 +263,14 @@ mlx4_mp2mr(struct ibv_pd *pd, struct rte_mempool *mp)
 uint32_t
 mlx4_txq_add_mr(struct txq *txq, struct rte_mempool *mp, uint32_t i)
 {
-       struct ibv_mr *mr;
+       struct mlx4_mr *mr;
 
        /* Add a new entry, register MR first. */
        DEBUG("%p: discovered new memory pool \"%s\" (%p)",
              (void *)txq, mp->name, (void *)mp);
-       mr = mlx4_mp2mr(txq->priv->pd, mp);
+       mr = mlx4_mr_get(txq->priv, mp);
        if (unlikely(mr == NULL)) {
-               DEBUG("%p: unable to configure MR, ibv_reg_mr() failed.",
+               DEBUG("%p: unable to configure MR, mlx4_mr_get() failed",
                      (void *)txq);
                return (uint32_t)-1;
        }
@@ -219,7 +279,7 @@ mlx4_txq_add_mr(struct txq *txq, struct rte_mempool *mp, uint32_t i)
                DEBUG("%p: MR <-> MP table full, dropping oldest entry.",
                      (void *)txq);
                --i;
-               claim_zero(ibv_dereg_mr(txq->mp2mr[0].mr));
+               mlx4_mr_put(txq->mp2mr[0].mr);
                memmove(&txq->mp2mr[0], &txq->mp2mr[1],
                        (sizeof(txq->mp2mr) - sizeof(txq->mp2mr[0])));
        }