Skip to content

Commit

Permalink
vdpa/mlx5: Implement susupend virtqueue callback
Browse files Browse the repository at this point in the history 
Implement the suspend callback allowing to suspend the virtqueues so
they stop processing descriptors. This is required to allow to query a
consistent state of the virtqueue while live migration is taking place.

Signed-off-by: Eli Cohen <elic@nvidia.com>
Message-Id: <20220714113927.85729-2-elic@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
  • Loading branch information
@elic307i @mstsirkin
elic307i authored and mstsirkin committed Aug 11, 2022
1 parent ad14635 commit cae15c2
Show file tree
Hide file tree
Showing 2 changed files with 88 additions and 3 deletions.
83 changes: 80 additions & 3 deletions drivers/vdpa/mlx5/net/mlx5_vnet.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -164,6 +164,7 @@ struct mlx5_vdpa_net {
bool setup;
u32 cur_num_vqs;
u32 rqt_size;
bool nb_registered;
struct notifier_block nb;
struct vdpa_callback config_cb;
struct mlx5_vdpa_wq_ent cvq_ent;
Expand Down Expand Up @@ -895,6 +896,7 @@ static int create_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtque
if (err)
goto err_cmd;

mvq->fw_state = MLX5_VIRTIO_NET_Q_OBJECT_STATE_INIT;
kfree(in);
mvq->virtq_id = MLX5_GET(general_obj_out_cmd_hdr, out, obj_id);

Expand Down Expand Up @@ -922,6 +924,7 @@ static void destroy_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtq
mlx5_vdpa_warn(&ndev->mvdev, "destroy virtqueue 0x%x\n", mvq->virtq_id);
return;
}
mvq->fw_state = MLX5_VIRTIO_NET_Q_OBJECT_NONE;
umems_destroy(ndev, mvq);
}

Expand Down Expand Up @@ -1121,6 +1124,20 @@ static int query_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueu
return err;
}

static bool is_valid_state_change(int oldstate, int newstate)
{
switch (oldstate) {
case MLX5_VIRTIO_NET_Q_OBJECT_STATE_INIT:
return newstate == MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY;
case MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY:
return newstate == MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND;
case MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND:
case MLX5_VIRTIO_NET_Q_OBJECT_STATE_ERR:
default:
return false;
}
}

static int modify_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq, int state)
{
int inlen = MLX5_ST_SZ_BYTES(modify_virtio_net_q_in);
Expand All @@ -1130,6 +1147,12 @@ static int modify_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtque
void *in;
int err;

if (mvq->fw_state == MLX5_VIRTIO_NET_Q_OBJECT_NONE)
return 0;

if (!is_valid_state_change(mvq->fw_state, state))
return -EINVAL;

in = kzalloc(inlen, GFP_KERNEL);
if (!in)
return -ENOMEM;
Expand Down Expand Up @@ -1992,6 +2015,7 @@ static void mlx5_vdpa_set_vq_ready(struct vdpa_device *vdev, u16 idx, bool ready
struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
struct mlx5_vdpa_virtqueue *mvq;
int err;

if (!mvdev->actual_features)
return;
Expand All @@ -2005,8 +2029,16 @@ static void mlx5_vdpa_set_vq_ready(struct vdpa_device *vdev, u16 idx, bool ready
}

mvq = &ndev->vqs[idx];
if (!ready)
if (!ready) {
suspend_vq(ndev, mvq);
} else {
err = modify_virtqueue(ndev, mvq, MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY);
if (err) {
mlx5_vdpa_warn(mvdev, "modify VQ %d to ready failed (%d)\n", idx, err);
ready = false;
}
}


mvq->ready = ready;
}
Expand Down Expand Up @@ -2733,6 +2765,37 @@ static int mlx5_vdpa_get_vendor_vq_stats(struct vdpa_device *vdev, u16 idx,
return err;
}

static void mlx5_vdpa_cvq_suspend(struct mlx5_vdpa_dev *mvdev)
{
struct mlx5_control_vq *cvq;

if (!(mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ)))
return;

cvq = &mvdev->cvq;
cvq->ready = false;
}

static int mlx5_vdpa_suspend(struct vdpa_device *vdev)
{
struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
struct mlx5_vdpa_virtqueue *mvq;
int i;

down_write(&ndev->reslock);
mlx5_notifier_unregister(mvdev->mdev, &ndev->nb);
ndev->nb_registered = false;
flush_workqueue(ndev->mvdev.wq);
for (i = 0; i < ndev->cur_num_vqs; i++) {
mvq = &ndev->vqs[i];
suspend_vq(ndev, mvq);
}
mlx5_vdpa_cvq_suspend(mvdev);
up_write(&ndev->reslock);
return 0;
}

static const struct vdpa_config_ops mlx5_vdpa_ops = {
.set_vq_address = mlx5_vdpa_set_vq_address,
.set_vq_num = mlx5_vdpa_set_vq_num,
Expand Down Expand Up @@ -2763,6 +2826,7 @@ static const struct vdpa_config_ops mlx5_vdpa_ops = {
.get_generation = mlx5_vdpa_get_generation,
.set_map = mlx5_vdpa_set_map,
.free = mlx5_vdpa_free,
.suspend = mlx5_vdpa_suspend,
};

static int query_mtu(struct mlx5_core_dev *mdev, u16 *mtu)
Expand Down Expand Up @@ -2828,6 +2892,7 @@ static void init_mvqs(struct mlx5_vdpa_net *ndev)
mvq->index = i;
mvq->ndev = ndev;
mvq->fwqp.fw = true;
mvq->fw_state = MLX5_VIRTIO_NET_Q_OBJECT_NONE;
}
for (; i < ndev->mvdev.max_vqs; i++) {
mvq = &ndev->vqs[i];
Expand Down Expand Up @@ -2902,13 +2967,21 @@ static int event_handler(struct notifier_block *nb, unsigned long event, void *p
switch (eqe->sub_type) {
case MLX5_PORT_CHANGE_SUBTYPE_DOWN:
case MLX5_PORT_CHANGE_SUBTYPE_ACTIVE:
down_read(&ndev->reslock);
if (!ndev->nb_registered) {
up_read(&ndev->reslock);
return NOTIFY_DONE;
}
wqent = kzalloc(sizeof(*wqent), GFP_ATOMIC);
if (!wqent)
if (!wqent) {
up_read(&ndev->reslock);
return NOTIFY_DONE;
}

wqent->mvdev = &ndev->mvdev;
INIT_WORK(&wqent->work, update_carrier);
queue_work(ndev->mvdev.wq, &wqent->work);
up_read(&ndev->reslock);
ret = NOTIFY_OK;
break;
default:
Expand Down Expand Up @@ -3062,6 +3135,7 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,

ndev->nb.notifier_call = event_handler;
mlx5_notifier_register(mdev, &ndev->nb);
ndev->nb_registered = true;
mvdev->vdev.mdev = &mgtdev->mgtdev;
err = _vdpa_register_device(&mvdev->vdev, max_vqs + 1);
if (err)
Expand Down Expand Up @@ -3093,7 +3167,10 @@ static void mlx5_vdpa_dev_del(struct vdpa_mgmt_dev *v_mdev, struct vdpa_device *
struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
struct workqueue_struct *wq;

mlx5_notifier_unregister(mvdev->mdev, &ndev->nb);
if (ndev->nb_registered) {
mlx5_notifier_unregister(mvdev->mdev, &ndev->nb);
ndev->nb_registered = false;
}
wq = mvdev->wq;
mvdev->wq = NULL;
destroy_workqueue(wq);
Expand Down
8 changes: 8 additions & 0 deletions include/linux/mlx5/mlx5_ifc_vdpa.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -150,6 +150,14 @@ enum {
MLX5_VIRTIO_NET_Q_OBJECT_STATE_ERR = 0x3,
};

/* This indicates that the object was not created or has already
* been desroyed. It is very safe to assume that this object will never
* have so many states
*/
enum {
MLX5_VIRTIO_NET_Q_OBJECT_NONE = 0xffffffff
};

enum {
MLX5_RQTC_LIST_Q_TYPE_RQ = 0x0,
MLX5_RQTC_LIST_Q_TYPE_VIRTIO_NET_Q = 0x1,
Expand Down

0 comments on commit cae15c2

Please sign in to comment.