Today, mlx5_vdpa gets started by preallocate 1:1 DMA mapping at device creation time, while this 1:1 mapping will be implicitly destroyed when the first .set_map call is invoked. Everytime when the .reset callback is invoked, any mapping left behind will be dropped then reset back to the initial 1:1 DMA mapping.
In order to reduce excessive memory mapping cost during live migration, it is desirable to decouple the vhost-vdpa iotlb abstraction from the virtio device life cycle, i.e. mappings should be left intact across virtio device reset. Leverage the .reset_map callback to reset memory mapping, then the device .reset routine can run free from having to clean up memory mappings. Signed-off-by: Si-Wei Liu <[email protected]> --- RFC v1 -> v2: - fix error path when both CVQ and DVQ fall in same asid --- drivers/vdpa/mlx5/core/mlx5_vdpa.h | 1 + drivers/vdpa/mlx5/core/mr.c | 70 +++++++++++++++++++++++--------------- drivers/vdpa/mlx5/net/mlx5_vnet.c | 18 +++++++--- 3 files changed, 56 insertions(+), 33 deletions(-) diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h index b53420e..5c9a25a 100644 --- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h +++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h @@ -123,6 +123,7 @@ int mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb, unsigned int asid); void mlx5_vdpa_destroy_mr(struct mlx5_vdpa_dev *mvdev); void mlx5_vdpa_destroy_mr_asid(struct mlx5_vdpa_dev *mvdev, unsigned int asid); +int mlx5_vdpa_reset_mr(struct mlx5_vdpa_dev *mvdev, unsigned int asid); #define mlx5_vdpa_warn(__dev, format, ...) \ dev_warn((__dev)->mdev->device, "%s:%d:(pid %d) warning: " format, __func__, __LINE__, \ diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c index 5a1971fc..ec2c7b4e1 100644 --- a/drivers/vdpa/mlx5/core/mr.c +++ b/drivers/vdpa/mlx5/core/mr.c @@ -489,21 +489,15 @@ static void destroy_user_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr } } -static void _mlx5_vdpa_destroy_cvq_mr(struct mlx5_vdpa_dev *mvdev, unsigned int asid) +static void _mlx5_vdpa_destroy_cvq_mr(struct mlx5_vdpa_dev *mvdev) { - if (mvdev->group2asid[MLX5_VDPA_CVQ_GROUP] != asid) - return; - prune_iotlb(mvdev); } -static void _mlx5_vdpa_destroy_dvq_mr(struct mlx5_vdpa_dev *mvdev, unsigned int asid) +static void _mlx5_vdpa_destroy_dvq_mr(struct mlx5_vdpa_dev *mvdev) { struct mlx5_vdpa_mr *mr = &mvdev->mr; - if (mvdev->group2asid[MLX5_VDPA_DATAVQ_GROUP] != asid) - return; - if (!mr->initialized) return; @@ -521,8 +515,10 @@ void mlx5_vdpa_destroy_mr_asid(struct mlx5_vdpa_dev *mvdev, unsigned int asid) mutex_lock(&mr->mkey_mtx); - _mlx5_vdpa_destroy_dvq_mr(mvdev, asid); - _mlx5_vdpa_destroy_cvq_mr(mvdev, asid); + if (mvdev->group2asid[MLX5_VDPA_DATAVQ_GROUP] == asid) + _mlx5_vdpa_destroy_dvq_mr(mvdev); + if (mvdev->group2asid[MLX5_VDPA_CVQ_GROUP] == asid) + _mlx5_vdpa_destroy_cvq_mr(mvdev); mutex_unlock(&mr->mkey_mtx); } @@ -534,25 +530,17 @@ void mlx5_vdpa_destroy_mr(struct mlx5_vdpa_dev *mvdev) } static int _mlx5_vdpa_create_cvq_mr(struct mlx5_vdpa_dev *mvdev, - struct vhost_iotlb *iotlb, - unsigned int asid) + struct vhost_iotlb *iotlb) { - if (mvdev->group2asid[MLX5_VDPA_CVQ_GROUP] != asid) - return 0; - return dup_iotlb(mvdev, iotlb); } static int _mlx5_vdpa_create_dvq_mr(struct mlx5_vdpa_dev *mvdev, - struct vhost_iotlb *iotlb, - unsigned int asid) + struct vhost_iotlb *iotlb) { struct mlx5_vdpa_mr *mr = &mvdev->mr; int err; - if (mvdev->group2asid[MLX5_VDPA_DATAVQ_GROUP] != asid) - return 0; - if (mr->initialized) return 0; @@ -574,18 +562,22 @@ static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, { int err; - err = _mlx5_vdpa_create_dvq_mr(mvdev, iotlb, asid); - if (err) - return err; - - err = _mlx5_vdpa_create_cvq_mr(mvdev, iotlb, asid); - if (err) - goto out_err; + if (mvdev->group2asid[MLX5_VDPA_DATAVQ_GROUP] == asid) { + err = _mlx5_vdpa_create_dvq_mr(mvdev, iotlb); + if (err) + return err; + } + if (mvdev->group2asid[MLX5_VDPA_CVQ_GROUP] == asid) { + err = _mlx5_vdpa_create_cvq_mr(mvdev, iotlb); + if (err) + goto out_err; + } return 0; out_err: - _mlx5_vdpa_destroy_dvq_mr(mvdev, asid); + if (mvdev->group2asid[MLX5_VDPA_DATAVQ_GROUP] == asid) + _mlx5_vdpa_destroy_dvq_mr(mvdev); return err; } @@ -601,6 +593,28 @@ int mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb, return err; } +int mlx5_vdpa_reset_mr(struct mlx5_vdpa_dev *mvdev, unsigned int asid) +{ + struct mlx5_vdpa_mr *mr = &mvdev->mr; + int err = 0; + + if (asid != 0) + return 0; + + mutex_lock(&mr->mkey_mtx); + if (!mr->user_mr) + goto out; + _mlx5_vdpa_destroy_dvq_mr(mvdev); + if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) { + err = _mlx5_vdpa_create_dvq_mr(mvdev, NULL); + if (err) + mlx5_vdpa_warn(mvdev, "create DMA MR failed\n"); + } +out: + mutex_unlock(&mr->mkey_mtx); + return err; +} + int mlx5_vdpa_handle_set_map(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb, bool *change_map, unsigned int asid) { diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index 37be945..3cb5db6 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -2824,7 +2824,6 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev) unregister_link_notifier(ndev); teardown_driver(ndev); clear_vqs_ready(ndev); - mlx5_vdpa_destroy_mr(&ndev->mvdev); ndev->mvdev.status = 0; ndev->mvdev.suspended = false; ndev->cur_num_vqs = 0; @@ -2835,10 +2834,6 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev) init_group_to_asid_map(mvdev); ++mvdev->generation; - if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) { - if (mlx5_vdpa_create_mr(mvdev, NULL, 0)) - mlx5_vdpa_warn(mvdev, "create MR failed\n"); - } up_write(&ndev->reslock); return 0; @@ -2903,6 +2898,18 @@ static int mlx5_vdpa_set_map(struct vdpa_device *vdev, unsigned int asid, return err; } +static int mlx5_vdpa_reset_map(struct vdpa_device *vdev, unsigned int asid) +{ + struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev); + struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev); + int err; + + down_write(&ndev->reslock); + err = mlx5_vdpa_reset_mr(mvdev, asid); + up_write(&ndev->reslock); + return err; +} + static struct device *mlx5_get_vq_dma_dev(struct vdpa_device *vdev, u16 idx) { struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev); @@ -3162,6 +3169,7 @@ static int mlx5_set_group_asid(struct vdpa_device *vdev, u32 group, .set_config = mlx5_vdpa_set_config, .get_generation = mlx5_vdpa_get_generation, .set_map = mlx5_vdpa_set_map, + .reset_map = mlx5_vdpa_reset_map, .set_group_asid = mlx5_set_group_asid, .get_vq_dma_dev = mlx5_get_vq_dma_dev, .free = mlx5_vdpa_free, -- 1.8.3.1 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
