vdpa/mlx5: Add support for running with virtio_vdpa

In order to support running vdpa using vritio_vdpa driver, we need  to
create a different kind of MR, one that has 1:1 mapping, since the
addresses referring to virtqueues are dma addresses.

We create the 1:1 MR in mlx5_vdpa_dev_add() only in case firmware
supports the general capability umem_uid_0. The reason for that is that
1:1 MRs must be created with uid == 0 while virtqueue objects can be
created with uid == 0 only when the firmware capability is on.

If the set_map() callback is called with new translations provided
through iotlb, the driver will destroy the 1:1 MR and create a regular
one.

Signed-off-by: Eli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20210602085854.62690-1-elic@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
index b6cc53b..09a16a3 100644 (file)
--- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h
+++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
@@ -35,6 +35,7 @@ struct mlx5_vdpa_mr {
 
        /* serialize mkey creation and destruction */
        struct mutex mkey_mtx;
+       bool user_mr;
 };
 
 struct mlx5_vdpa_resources {

diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
index cfa56a5..dcee603 100644 (file)
--- a/drivers/vdpa/mlx5/core/mr.c
+++ b/drivers/vdpa/mlx5/core/mr.c
@@ -355,7 +355,7 @@ err_alloc:
  * indirect memory key that provides access to the enitre address space given
  * by iotlb.
  */
-static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb)
+static int create_user_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb)
 {
        struct mlx5_vdpa_mr *mr = &mvdev->mr;
        struct mlx5_vdpa_direct_mr *dmr;
@@ -369,9 +369,6 @@ static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb
        int err = 0;
        int nnuls;
 
-       if (mr->initialized)
-               return 0;
-
        INIT_LIST_HEAD(&mr->head);
        for (map = vhost_iotlb_itree_first(iotlb, start, last); map;
             map = vhost_iotlb_itree_next(map, start, last)) {
@@ -409,7 +406,7 @@ static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb
        if (err)
                goto err_chain;
 
-       mr->initialized = true;
+       mr->user_mr = true;
        return 0;
 
 err_chain:
@@ -421,33 +418,94 @@ err_chain:
        return err;
 }
 
-int mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb)
+static int create_dma_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr)
+{
+       int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
+       void *mkc;
+       u32 *in;
+       int err;
+
+       in = kzalloc(inlen, GFP_KERNEL);
+       if (!in)
+               return -ENOMEM;
+
+       mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
+
+       MLX5_SET(mkc, mkc, access_mode_1_0, MLX5_MKC_ACCESS_MODE_PA);
+       MLX5_SET(mkc, mkc, length64, 1);
+       MLX5_SET(mkc, mkc, lw, 1);
+       MLX5_SET(mkc, mkc, lr, 1);
+       MLX5_SET(mkc, mkc, pd, mvdev->res.pdn);
+       MLX5_SET(mkc, mkc, qpn, 0xffffff);
+
+       err = mlx5_vdpa_create_mkey(mvdev, &mr->mkey, in, inlen);
+       if (!err)
+               mr->user_mr = false;
+
+       kfree(in);
+       return err;
+}
+
+static void destroy_dma_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr)
+{
+       mlx5_vdpa_destroy_mkey(mvdev, &mr->mkey);
+}
+
+static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb)
 {
        struct mlx5_vdpa_mr *mr = &mvdev->mr;
        int err;
 
-       mutex_lock(&mr->mkey_mtx);
+       if (mr->initialized)
+               return 0;
+
+       if (iotlb)
+               err = create_user_mr(mvdev, iotlb);
+       else
+               err = create_dma_mr(mvdev, mr);
+
+       if (!err)
+               mr->initialized = true;
+
+       return err;
+}
+
+int mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb)
+{
+       int err;
+
+       mutex_lock(&mvdev->mr.mkey_mtx);
        err = _mlx5_vdpa_create_mr(mvdev, iotlb);
-       mutex_unlock(&mr->mkey_mtx);
+       mutex_unlock(&mvdev->mr.mkey_mtx);
        return err;
 }
 
-void mlx5_vdpa_destroy_mr(struct mlx5_vdpa_dev *mvdev)
+static void destroy_user_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr)
 {
-       struct mlx5_vdpa_mr *mr = &mvdev->mr;
        struct mlx5_vdpa_direct_mr *dmr;
        struct mlx5_vdpa_direct_mr *n;
 
-       mutex_lock(&mr->mkey_mtx);
-       if (!mr->initialized)
-               goto out;
-
        destroy_indirect_key(mvdev, mr);
        list_for_each_entry_safe_reverse(dmr, n, &mr->head, list) {
                list_del_init(&dmr->list);
                unmap_direct_mr(mvdev, dmr);
                kfree(dmr);
        }
+}
+
+void mlx5_vdpa_destroy_mr(struct mlx5_vdpa_dev *mvdev)
+{
+       struct mlx5_vdpa_mr *mr = &mvdev->mr;
+
+       mutex_lock(&mr->mkey_mtx);
+       if (!mr->initialized)
+               goto out;
+
+       if (mr->user_mr)
+               destroy_user_mr(mvdev, mr);
+       else
+               destroy_dma_mr(mvdev, mr);
+
        memset(mr, 0, sizeof(*mr));
        mr->initialized = false;
 out:

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 2b74e34..d404ea7 100644 (file)
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1781,6 +1781,10 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
                ndev->mvdev.status = 0;
                ndev->mvdev.mlx_features = 0;
                ++mvdev->generation;
+               if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) {
+                       if (mlx5_vdpa_create_mr(mvdev, NULL))
+                               mlx5_vdpa_warn(mvdev, "create MR failed\n");
+               }
                return;
        }
 
@@ -1861,6 +1865,7 @@ static void mlx5_vdpa_free(struct vdpa_device *vdev)
        ndev = to_mlx5_vdpa_ndev(mvdev);
 
        free_resources(ndev);
+       mlx5_vdpa_destroy_mr(mvdev);
        if (!is_zero_ether_addr(ndev->config.mac)) {
                pfmdev = pci_get_drvdata(pci_physfn(mvdev->mdev->pdev));
                mlx5_mpfs_del_mac(pfmdev, ndev->config.mac);
@@ -2037,9 +2042,15 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name)
        if (err)
                goto err_mpfs;
 
+       if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) {
+               err = mlx5_vdpa_create_mr(mvdev, NULL);
+               if (err)
+                       goto err_res;
+       }
+
        err = alloc_resources(ndev);
        if (err)
-               goto err_res;
+               goto err_mr;
 
        mvdev->vdev.mdev = &mgtdev->mgtdev;
        err = _vdpa_register_device(&mvdev->vdev, 2 * mlx5_vdpa_max_qps(max_vqs));
@@ -2051,6 +2062,8 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name)
 
 err_reg:
        free_resources(ndev);
+err_mr:
+       mlx5_vdpa_destroy_mr(mvdev);
 err_res:
        mlx5_vdpa_free_resources(&ndev->mvdev);
 err_mpfs: