Jason Wang
2021-Jun-01 02:09 UTC
[PATCH v1] vdpa/mlx5: Add support for running with virtio_vdpa
? 2021/6/1 ??12:04, Eli Cohen ??:> 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 at nvidia.com> > --- > v0 --> v1: > 1. Clear user_mr after successful creation of DMA MR > 2. Check return code of mlx5_vdpa_create_mr() and emit warning if > failed. > > drivers/vdpa/mlx5/core/mlx5_vdpa.h | 1 + > drivers/vdpa/mlx5/core/mr.c | 84 +++++++++++++++++++++++++----- > drivers/vdpa/mlx5/net/mlx5_vnet.c | 15 +++++- > 3 files changed, 85 insertions(+), 15 deletions(-) > > diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h > index b6cc53ba980c..09a16a3d1b2a 100644 > --- 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 800cfd1967ad..3c6c1d846f5e 100644 > --- a/drivers/vdpa/mlx5/core/mr.c > +++ b/drivers/vdpa/mlx5/core/mr.c > @@ -360,7 +360,7 @@ static int add_direct_chain(struct mlx5_vdpa_dev *mvdev, u64 start, u64 size, u8 > * 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; > @@ -374,9 +374,6 @@ 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)) { > @@ -414,7 +411,7 @@ 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: > @@ -426,33 +423,92 @@ static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb > 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;Rethink about this. I wonder this is correct when we fail to create memory key. In this case, user_mr is true but user_mr is already destroyed. Can this lead double free for user mr? Thanks> + > + 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); > + > + 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 fdf3e74bffbd..02a05492204c 100644 > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c > @@ -1780,6 +1780,10 @@ 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; > } > > @@ -1859,6 +1863,7 @@ static void mlx5_vdpa_free(struct vdpa_device *vdev) > ndev = to_mlx5_vdpa_ndev(mvdev); > > free_resources(ndev); > + mlx5_vdpa_destroy_mr(mvdev); > mlx5_vdpa_free_resources(&ndev->mvdev); > mutex_destroy(&ndev->reslock); > } > @@ -2023,9 +2028,15 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name) > if (err) > goto err_mtu; > > + 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)); > @@ -2037,6 +2048,8 @@ 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_mtu: