hw/rdma: Free all receive buffers when QP is destroyed

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 <yuval.shaia@oracle.com>
Reviewed-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Message-Id: <1552300155-25216-8-git-send-email-yuval.shaia@oracle.com>
Reviewed-by: Kamal Heib <kamalheib1@gmail.com>
Signed-off-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>

6 files changed, 63 insertions, 9 deletions

diff --git a/hw/rdma/rdma_backend.c b/hw/rdma/rdma_backend.c
index d0bbe57bd2..e124d8d16b 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 8e53a72bf2..c54eaf2e4a 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 a8c15b09ab..817153dc8c 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 b50e192b49..bac3b2f4a6 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 0a8abe572d..73f279104c 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 a8bf1d4fec..2d42249691 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)
 {