From: Eli Cohen <elic@nvidia.com>
Date: Thu, 14 Jul 2022 14:39:26 +0300
Subject: vdpa/mlx5: Implement susupend virtqueue callback
Patch-mainline: v6.0-rc1
Git-commit: cae15c2ed8e6e058bd5e32de292ab7982640161e
References: jsc#PED-1549
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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/vdpa/mlx5/net/mlx5_vnet.c | 83 +++++++++++++++++++++++++++++++++++--
include/linux/mlx5/mlx5_ifc_vdpa.h | 8 +++
2 files changed, 88 insertions(+), 3 deletions(-)
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -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;
@@ -895,6 +896,7 @@ static int create_virtqueue(struct mlx5_
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);
@@ -922,6 +924,7 @@ static void destroy_virtqueue(struct mlx
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);
}
@@ -1121,6 +1124,20 @@ err_cmd:
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);
@@ -1130,6 +1147,12 @@ static int modify_virtqueue(struct mlx5_
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;
@@ -1992,6 +2015,7 @@ static void mlx5_vdpa_set_vq_ready(struc
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;
@@ -2005,8 +2029,16 @@ static void mlx5_vdpa_set_vq_ready(struc
}
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;
}
@@ -2727,6 +2759,37 @@ out_err:
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,
@@ -2756,6 +2819,7 @@ static const struct vdpa_config_ops mlx5
.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)
@@ -2821,6 +2885,7 @@ static void init_mvqs(struct mlx5_vdpa_n
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];
@@ -2895,13 +2960,21 @@ static int event_handler(struct notifier
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:
@@ -3055,6 +3128,7 @@ static int mlx5_vdpa_dev_add(struct vdpa
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)
@@ -3086,7 +3160,10 @@ static void mlx5_vdpa_dev_del(struct vdp
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);
--- a/include/linux/mlx5/mlx5_ifc_vdpa.h
+++ b/include/linux/mlx5/mlx5_ifc_vdpa.h
@@ -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,