Jason Wang
2021-May-31 06:44 UTC
[PATCH 2/2] vdpa/mlx5: Add support for running with virtio_vdpa
? 2021/5/31 ??1:13, Eli Cohen ??:> On Mon, May 31, 2021 at 11:16:11AM +0800, Jason Wang wrote: >> ? 2021/5/30 ??3:54, 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> >>> --- >>> drivers/vdpa/mlx5/core/mlx5_vdpa.h | 1 + >>> drivers/vdpa/mlx5/core/mr.c | 81 ++++++++++++++++++++++++------ >>> drivers/vdpa/mlx5/net/mlx5_vnet.c | 13 ++++- >>> 3 files changed, 80 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..020c0ce4d203 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 +423,89 @@ 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); >>> + 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); >> >> Do we need to set user_mr to false here? > I think the right place to do this should be inside create_dma_mr(), the > same as we set it true in ().Fine.>> >>> + >>> + 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..f16756661c19 100644 >>> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c >>> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c >>> @@ -1780,6 +1780,8 @@ 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)) >>> + mlx5_vdpa_create_mr(mvdev, NULL); >> >> I wonder if it's possible/worth to avoid the destroy and re-create of dma MR >> here. (In the case of it has been used by us). > If it is a user MR, you must destroy it since it is useless. If it's > DMA MR, you might be able to do it but since the DMA MR's are > lightweight, I don't think it's worth it.Yes, I agree. Thanks> >> Thanks >> >> >>> return; >>> } >>> @@ -1859,6 +1861,7 @@ 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 +2026,15 @@ 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 +2046,8 @@ 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: