Re: [PATCH v1] vdpa/mlx5: Add support for running with virtio_vdpa
From: Jason Wang
Date: Tue Jun 01 2021 - 01:00:32 EST
在 2021/6/1 上午11:40, Eli Cohen 写道:
On Tue, Jun 01, 2021 at 10:09:45AM +0800, Jason Wang wrote:
在 2021/6/1 上午12:04, Eli Cohen 写道:
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@xxxxxxxxxx>
---
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?
mr->user_mr is a binary flag and its sole purpose is to tell the flavour
of the MR but is valid only when mr->initialized is true. MR won't be
freed if mr->initialized is false.
So we have:
static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct
vhost_iotlb *iotlb)
{
struct mlx5_vdpa_mr *mr = &mvdev->mr;
int err;
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;
}
It looks to me we need to check err before set mr->initialized.
Thanks
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: