Re: [Qemu-devel] [PATCH v6 07/11] hw/rdma: Free all receive buffers when QP is destroyed

[Kamal Heib]

On 3/11/19 12:29 PM, Yuval Shaia wrote:
> When QP is destroyed the backend QP is destroyed as well. This ensures
> we clean all received buffer we posted to it.
> However, a contexts of these buffers are still remain in the device.
> Fix it by maintaining a list of buffer's context and free them when QP
> is destroyed.
> 
> Signed-off-by: Yuval Shaia <address@hidden>
> Reviewed-by: Marcel Apfelbaum <address@hidden>
> ---
>  hw/rdma/rdma_backend.c      | 26 ++++++++++++++++++++------
>  hw/rdma/rdma_backend.h      |  2 +-
>  hw/rdma/rdma_backend_defs.h |  2 +-
>  hw/rdma/rdma_rm.c           |  2 +-
>  hw/rdma/rdma_utils.c        | 29 +++++++++++++++++++++++++++++
>  hw/rdma/rdma_utils.h        | 11 +++++++++++
>  6 files changed, 63 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/rdma/rdma_backend.c b/hw/rdma/rdma_backend.c
> index d0bbe57..e124d8d 100644
> --- a/hw/rdma/rdma_backend.c
> +++ b/hw/rdma/rdma_backend.c
> @@ -39,6 +39,7 @@
>  typedef struct BackendCtx {
>      void *up_ctx;
>      struct ibv_sge sge; /* Used to save MAD recv buffer */
> +    RdmaBackendQP *backend_qp; /* To maintain recv buffers */
>  } BackendCtx;
>  
>  struct backend_umad {
> @@ -73,6 +74,7 @@ static void free_cqe_ctx(gpointer data, gpointer user_data)
>      bctx = rdma_rm_get_cqe_ctx(rdma_dev_res, cqe_ctx_id);
>      if (bctx) {
>          rdma_rm_dealloc_cqe_ctx(rdma_dev_res, cqe_ctx_id);
> +        atomic_dec(&rdma_dev_res->stats.missing_cqe);
>      }
>      g_free(bctx);
>  }
> @@ -85,13 +87,15 @@ static void clean_recv_mads(RdmaBackendDev *backend_dev)
>          cqe_ctx_id = rdma_protected_qlist_pop_int64(&backend_dev->
>                                                      recv_mads_list);
>          if (cqe_ctx_id != -ENOENT) {
> +            atomic_inc(&backend_dev->rdma_dev_res->stats.missing_cqe);
>              free_cqe_ctx(GINT_TO_POINTER(cqe_ctx_id),
>                           backend_dev->rdma_dev_res);
>          }
>      } while (cqe_ctx_id != -ENOENT);
>  }
>  
> -static int rdma_poll_cq(RdmaDeviceResources *rdma_dev_res, struct ibv_cq 
> *ibcq)
> +static int rdma_poll_cq(RdmaBackendDev *backend_dev,
> +                        RdmaDeviceResources *rdma_dev_res, struct ibv_cq 
> *ibcq)
>  {
>      int i, ne, total_ne = 0;
>      BackendCtx *bctx;
> @@ -113,6 +117,8 @@ static int rdma_poll_cq(RdmaDeviceResources 
> *rdma_dev_res, struct ibv_cq *ibcq)
>  
>              comp_handler(bctx->up_ctx, &wc[i]);
>  
> +            
> rdma_protected_gslist_remove_int32(&bctx->backend_qp->cqe_ctx_list,
> +                                               wc[i].wr_id);
>              rdma_rm_dealloc_cqe_ctx(rdma_dev_res, wc[i].wr_id);
>              g_free(bctx);
>          }
> @@ -175,14 +181,12 @@ static void *comp_handler_thread(void *arg)
>              }
>  
>              backend_dev->rdma_dev_res->stats.poll_cq_from_bk++;
> -            rdma_poll_cq(backend_dev->rdma_dev_res, ev_cq);
> +            rdma_poll_cq(backend_dev, backend_dev->rdma_dev_res, ev_cq);
>  
>              ibv_ack_cq_events(ev_cq, 1);
>          }
>      }
>  
> -    /* TODO: Post cqe for all remaining buffs that were posted */
> -
>      backend_dev->comp_thread.is_running = false;
>  
>      qemu_thread_exit(0);
> @@ -311,7 +315,7 @@ void rdma_backend_poll_cq(RdmaDeviceResources 
> *rdma_dev_res, RdmaBackendCQ *cq)
>      int polled;
>  
>      rdma_dev_res->stats.poll_cq_from_guest++;
> -    polled = rdma_poll_cq(rdma_dev_res, cq->ibcq);
> +    polled = rdma_poll_cq(cq->backend_dev, rdma_dev_res, cq->ibcq);
>      if (!polled) {
>          rdma_dev_res->stats.poll_cq_from_guest_empty++;
>      }
> @@ -501,6 +505,7 @@ void rdma_backend_post_send(RdmaBackendDev *backend_dev,
>  
>      bctx = g_malloc0(sizeof(*bctx));
>      bctx->up_ctx = ctx;
> +    bctx->backend_qp = qp;
>  
>      rc = rdma_rm_alloc_cqe_ctx(backend_dev->rdma_dev_res, &bctx_id, bctx);
>      if (unlikely(rc)) {
> @@ -508,6 +513,8 @@ void rdma_backend_post_send(RdmaBackendDev *backend_dev,
>          goto err_free_bctx;
>      }
>  
> +    rdma_protected_gslist_append_int32(&qp->cqe_ctx_list, bctx_id);
> +
>      rc = build_host_sge_array(backend_dev->rdma_dev_res, new_sge, sge, 
> num_sge,
>                                &backend_dev->rdma_dev_res->stats.tx_len);
>      if (rc) {
> @@ -616,6 +623,7 @@ void rdma_backend_post_recv(RdmaBackendDev *backend_dev,
>  
>      bctx = g_malloc0(sizeof(*bctx));
>      bctx->up_ctx = ctx;
> +    bctx->backend_qp = qp;
>  
>      rc = rdma_rm_alloc_cqe_ctx(rdma_dev_res, &bctx_id, bctx);
>      if (unlikely(rc)) {
> @@ -623,6 +631,8 @@ void rdma_backend_post_recv(RdmaBackendDev *backend_dev,
>          goto err_free_bctx;
>      }
>  
> +    rdma_protected_gslist_append_int32(&qp->cqe_ctx_list, bctx_id);
> +
>      rc = build_host_sge_array(rdma_dev_res, new_sge, sge, num_sge,
>                                &backend_dev->rdma_dev_res->stats.rx_bufs_len);
>      if (rc) {
> @@ -762,6 +772,8 @@ int rdma_backend_create_qp(RdmaBackendQP *qp, uint8_t 
> qp_type,
>          return -EIO;
>      }
>  
> +    rdma_protected_gslist_init(&qp->cqe_ctx_list);
> +
>      qp->ibpd = pd->ibpd;
>  
>      /* TODO: Query QP to get max_inline_data and save it to be used in send 
> */
> @@ -919,11 +931,13 @@ int rdma_backend_query_qp(RdmaBackendQP *qp, struct 
> ibv_qp_attr *attr,
>      return ibv_query_qp(qp->ibqp, attr, attr_mask, init_attr);
>  }
>  
> -void rdma_backend_destroy_qp(RdmaBackendQP *qp)
> +void rdma_backend_destroy_qp(RdmaBackendQP *qp, RdmaDeviceResources *dev_res)
>  {
>      if (qp->ibqp) {
>          ibv_destroy_qp(qp->ibqp);
>      }
> +    g_slist_foreach(qp->cqe_ctx_list.list, free_cqe_ctx, dev_res);
> +    rdma_protected_gslist_destroy(&qp->cqe_ctx_list);
>  }
>  
>  #define CHK_ATTR(req, dev, member, fmt) ({ \
> diff --git a/hw/rdma/rdma_backend.h b/hw/rdma/rdma_backend.h
> index 8e53a72..c54eaf2 100644
> --- a/hw/rdma/rdma_backend.h
> +++ b/hw/rdma/rdma_backend.h
> @@ -102,7 +102,7 @@ int rdma_backend_qp_state_rts(RdmaBackendQP *qp, uint8_t 
> qp_type,
>                                uint32_t sq_psn, uint32_t qkey, bool use_qkey);
>  int rdma_backend_query_qp(RdmaBackendQP *qp, struct ibv_qp_attr *attr,
>                            int attr_mask, struct ibv_qp_init_attr *init_attr);
> -void rdma_backend_destroy_qp(RdmaBackendQP *qp);
> +void rdma_backend_destroy_qp(RdmaBackendQP *qp, RdmaDeviceResources 
> *dev_res);
>  
>  void rdma_backend_post_send(RdmaBackendDev *backend_dev,
>                              RdmaBackendQP *qp, uint8_t qp_type,
> diff --git a/hw/rdma/rdma_backend_defs.h b/hw/rdma/rdma_backend_defs.h
> index a8c15b0..817153d 100644
> --- a/hw/rdma/rdma_backend_defs.h
> +++ b/hw/rdma/rdma_backend_defs.h
> @@ -26,7 +26,6 @@ typedef struct RdmaDeviceResources RdmaDeviceResources;
>  
>  typedef struct RdmaBackendThread {
>      QemuThread thread;
> -    QemuMutex mutex;
>      bool run; /* Set by thread manager to let thread know it should exit */
>      bool is_running; /* Set by the thread to report its status */
>  } RdmaBackendThread;
> @@ -66,6 +65,7 @@ typedef struct RdmaBackendQP {
>      struct ibv_pd *ibpd;
>      struct ibv_qp *ibqp;
>      uint8_t sgid_idx;
> +    RdmaProtectedGSList cqe_ctx_list;
>  } RdmaBackendQP;
>  
>  #endif
> diff --git a/hw/rdma/rdma_rm.c b/hw/rdma/rdma_rm.c
> index b50e192..bac3b2f 100644
> --- a/hw/rdma/rdma_rm.c
> +++ b/hw/rdma/rdma_rm.c
> @@ -537,7 +537,7 @@ void rdma_rm_dealloc_qp(RdmaDeviceResources *dev_res, 
> uint32_t qp_handle)
>          return;
>      }
>  
> -    rdma_backend_destroy_qp(&qp->backend_qp);
> +    rdma_backend_destroy_qp(&qp->backend_qp, dev_res);
>  
>      rdma_res_tbl_dealloc(&dev_res->qp_tbl, qp->qpn);
>  }
> diff --git a/hw/rdma/rdma_utils.c b/hw/rdma/rdma_utils.c
> index 0a8abe5..73f2791 100644
> --- a/hw/rdma/rdma_utils.c
> +++ b/hw/rdma/rdma_utils.c
> @@ -90,3 +90,32 @@ int64_t rdma_protected_qlist_pop_int64(RdmaProtectedQList 
> *list)
>  
>      return qnum_get_uint(qobject_to(QNum, obj));
>  }
> +
> +void rdma_protected_gslist_init(RdmaProtectedGSList *list)
> +{
> +    qemu_mutex_init(&list->lock);
> +}
> +
> +void rdma_protected_gslist_destroy(RdmaProtectedGSList *list)
> +{
> +    if (list->list) {
> +        g_slist_free(list->list);
> +        list->list = NULL;
> +    }
> +}
> +
> +void rdma_protected_gslist_append_int32(RdmaProtectedGSList *list,
> +                                        int32_t value)
> +{
> +    qemu_mutex_lock(&list->lock);
> +    list->list = g_slist_prepend(list->list, GINT_TO_POINTER(value));
> +    qemu_mutex_unlock(&list->lock);
> +}
> +
> +void rdma_protected_gslist_remove_int32(RdmaProtectedGSList *list,
> +                                        int32_t value)
> +{
> +    qemu_mutex_lock(&list->lock);
> +    list->list = g_slist_remove(list->list, GINT_TO_POINTER(value));
> +    qemu_mutex_unlock(&list->lock);
> +}
> diff --git a/hw/rdma/rdma_utils.h b/hw/rdma/rdma_utils.h
> index a8bf1d4..2d42249 100644
> --- a/hw/rdma/rdma_utils.h
> +++ b/hw/rdma/rdma_utils.h
> @@ -34,12 +34,23 @@ typedef struct RdmaProtectedQList {
>      QList *list;
>  } RdmaProtectedQList;
>  
> +typedef struct RdmaProtectedGSList {
> +    QemuMutex lock;
> +    GSList *list;
> +} RdmaProtectedGSList;
> +
>  void *rdma_pci_dma_map(PCIDevice *dev, dma_addr_t addr, dma_addr_t plen);
>  void rdma_pci_dma_unmap(PCIDevice *dev, void *buffer, dma_addr_t len);
>  void rdma_protected_qlist_init(RdmaProtectedQList *list);
>  void rdma_protected_qlist_destroy(RdmaProtectedQList *list);
>  void rdma_protected_qlist_append_int64(RdmaProtectedQList *list, int64_t 
> value);
>  int64_t rdma_protected_qlist_pop_int64(RdmaProtectedQList *list);
> +void rdma_protected_gslist_init(RdmaProtectedGSList *list);
> +void rdma_protected_gslist_destroy(RdmaProtectedGSList *list);
> +void rdma_protected_gslist_append_int32(RdmaProtectedGSList *list,
> +                                        int32_t value);
> +void rdma_protected_gslist_remove_int32(RdmaProtectedGSList *list,
> +                                        int32_t value);
>  
>  static inline void addrconf_addr_eui48(uint8_t *eui, const char *addr)
>  {
> 

Reviewed-by: Kamal Heib <address@hidden>