netdevsim: add queue management API support

Add queue management API support. We need a way to reset queues
to test NAPI reordering, the queue management API provides a
handy scaffolding for that.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index 7b80796dbe26d17c22d5f2abed13bc5185be2e98..cfb079a345320ecc066a4f5f7c111a088041b089 100644 (file)
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -359,25 +359,24 @@ static int nsim_poll(struct napi_struct *napi, int budget)
        return done;
 }
 
-static int nsim_create_page_pool(struct nsim_rq *rq)
+static int nsim_create_page_pool(struct page_pool **p, struct napi_struct *napi)
 {
-       struct page_pool_params p = {
+       struct page_pool_params params = {
                .order = 0,
                .pool_size = NSIM_RING_SIZE,
                .nid = NUMA_NO_NODE,
-               .dev = &rq->napi.dev->dev,
-               .napi = &rq->napi,
+               .dev = &napi->dev->dev,
+               .napi = napi,
                .dma_dir = DMA_BIDIRECTIONAL,
-               .netdev = rq->napi.dev,
+               .netdev = napi->dev,
        };
+       struct page_pool *pool;
 
-       rq->page_pool = page_pool_create(&p);
-       if (IS_ERR(rq->page_pool)) {
-               int err = PTR_ERR(rq->page_pool);
+       pool = page_pool_create(&params);
+       if (IS_ERR(pool))
+               return PTR_ERR(pool);
 
-               rq->page_pool = NULL;
-               return err;
-       }
+       *p = pool;
        return 0;
 }
 
@@ -396,7 +395,7 @@ static int nsim_init_napi(struct netdevsim *ns)
        for (i = 0; i < dev->num_rx_queues; i++) {
                rq = ns->rq[i];
 
-               err = nsim_create_page_pool(rq);
+               err = nsim_create_page_pool(&rq->page_pool, &rq->napi);
                if (err)
                        goto err_pp_destroy;
        }
@@ -613,6 +612,116 @@ static void nsim_queue_free(struct nsim_rq *rq)
        kfree(rq);
 }
 
+/* Queue reset mode is controlled by ns->rq_reset_mode.
+ * - normal - new NAPI new pool (old NAPI enabled when new added)
+ * - mode 1 - allocate new pool (NAPI is only disabled / enabled)
+ * - mode 2 - new NAPI new pool (old NAPI removed before new added)
+ * - mode 3 - new NAPI new pool (old NAPI disabled when new added)
+ */
+struct nsim_queue_mem {
+       struct nsim_rq *rq;
+       struct page_pool *pp;
+};
+
+static int
+nsim_queue_mem_alloc(struct net_device *dev, void *per_queue_mem, int idx)
+{
+       struct nsim_queue_mem *qmem = per_queue_mem;
+       struct netdevsim *ns = netdev_priv(dev);
+       int err;
+
+       if (ns->rq_reset_mode > 3)
+               return -EINVAL;
+
+       if (ns->rq_reset_mode == 1)
+               return nsim_create_page_pool(&qmem->pp, &ns->rq[idx]->napi);
+
+       qmem->rq = nsim_queue_alloc();
+       if (!qmem->rq)
+               return -ENOMEM;
+
+       err = nsim_create_page_pool(&qmem->rq->page_pool, &qmem->rq->napi);
+       if (err)
+               goto err_free;
+
+       if (!ns->rq_reset_mode)
+               netif_napi_add_config(dev, &qmem->rq->napi, nsim_poll, idx);
+
+       return 0;
+
+err_free:
+       nsim_queue_free(qmem->rq);
+       return err;
+}
+
+static void nsim_queue_mem_free(struct net_device *dev, void *per_queue_mem)
+{
+       struct nsim_queue_mem *qmem = per_queue_mem;
+       struct netdevsim *ns = netdev_priv(dev);
+
+       page_pool_destroy(qmem->pp);
+       if (qmem->rq) {
+               if (!ns->rq_reset_mode)
+                       netif_napi_del(&qmem->rq->napi);
+               page_pool_destroy(qmem->rq->page_pool);
+               nsim_queue_free(qmem->rq);
+       }
+}
+
+static int
+nsim_queue_start(struct net_device *dev, void *per_queue_mem, int idx)
+{
+       struct nsim_queue_mem *qmem = per_queue_mem;
+       struct netdevsim *ns = netdev_priv(dev);
+
+       if (ns->rq_reset_mode == 1) {
+               ns->rq[idx]->page_pool = qmem->pp;
+               napi_enable(&ns->rq[idx]->napi);
+               return 0;
+       }
+
+       /* netif_napi_add()/_del() should normally be called from alloc/free,
+        * here we want to test various call orders.
+        */
+       if (ns->rq_reset_mode == 2) {
+               netif_napi_del(&ns->rq[idx]->napi);
+               netif_napi_add_config(dev, &qmem->rq->napi, nsim_poll, idx);
+       } else if (ns->rq_reset_mode == 3) {
+               netif_napi_add_config(dev, &qmem->rq->napi, nsim_poll, idx);
+               netif_napi_del(&ns->rq[idx]->napi);
+       }
+
+       ns->rq[idx] = qmem->rq;
+       napi_enable(&ns->rq[idx]->napi);
+
+       return 0;
+}
+
+static int nsim_queue_stop(struct net_device *dev, void *per_queue_mem, int idx)
+{
+       struct nsim_queue_mem *qmem = per_queue_mem;
+       struct netdevsim *ns = netdev_priv(dev);
+
+       napi_disable(&ns->rq[idx]->napi);
+
+       if (ns->rq_reset_mode == 1) {
+               qmem->pp = ns->rq[idx]->page_pool;
+               page_pool_disable_direct_recycling(qmem->pp);
+       } else {
+               qmem->rq = ns->rq[idx];
+       }
+
+       return 0;
+}
+
+static const struct netdev_queue_mgmt_ops nsim_queue_mgmt_ops = {
+       .ndo_queue_mem_size     = sizeof(struct nsim_queue_mem),
+       .ndo_queue_mem_alloc    = nsim_queue_mem_alloc,
+       .ndo_queue_mem_free     = nsim_queue_mem_free,
+       .ndo_queue_start        = nsim_queue_start,
+       .ndo_queue_stop         = nsim_queue_stop,
+};
+
 static ssize_t
 nsim_pp_hold_read(struct file *file, char __user *data,
                  size_t count, loff_t *ppos)
@@ -739,6 +848,7 @@ static int nsim_init_netdevsim(struct netdevsim *ns)
        ns->phc = phc;
        ns->netdev->netdev_ops = &nsim_netdev_ops;
        ns->netdev->stat_ops = &nsim_stat_ops;
+       ns->netdev->queue_mgmt_ops = &nsim_queue_mgmt_ops;
 
        err = nsim_udp_tunnels_info_create(ns->nsim_dev, ns->netdev);
        if (err)

diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 80fde64f4a7afe4d758d82313b7d90d013757286..8c50969b1240694af8c387bd109328bca8e475ea 100644 (file)
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -103,6 +103,8 @@ struct netdevsim {
        struct mock_phc *phc;
        struct nsim_rq **rq;
 
+       int rq_reset_mode;
+
        u64 tx_packets;
        u64 tx_bytes;
        u64 tx_dropped;