Re: [PATCH RESEND V2 3/3] vdpa/mlx5: Use consistent RQT size
From: Jason Wang
Date: Wed Apr 06 2022 - 07:36:35 EST
在 2022/4/6 上午10:35, Jason Wang 写道:
在 2022/4/4 下午7:24, Michael S. Tsirkin 写道:
On Mon, Apr 04, 2022 at 11:07:36AM +0000, Eli Cohen wrote:
From: Michael S. Tsirkin <mst@xxxxxxxxxx>
Sent: Monday, April 4, 2022 1:35 PM
To: Jason Wang <jasowang@xxxxxxxxxx>
Cc: Eli Cohen <elic@xxxxxxxxxx>; hdanton@xxxxxxxx;
virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx;
linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: [PATCH RESEND V2 3/3] vdpa/mlx5: Use consistent RQT size
On Tue, Mar 29, 2022 at 12:21:09PM +0800, Jason Wang wrote:
From: Eli Cohen <elic@xxxxxxxxxx>
The current code evaluates RQT size based on the configured number of
virtqueues. This can raise an issue in the following scenario:
Assume MQ was negotiated.
1. mlx5_vdpa_set_map() gets called.
2. handle_ctrl_mq() is called setting cur_num_vqs to some value,
lower
than the configured max VQs.
3. A second set_map gets called, but now a smaller number of VQs
is used
to evaluate the size of the RQT.
4. handle_ctrl_mq() is called with a value larger than what the
RQT can
hold. This will emit errors and the driver state is compromised.
To fix this, we use a new field in struct mlx5_vdpa_net to hold the
required number of entries in the RQT. This value is evaluated in
mlx5_vdpa_set_driver_features() where we have the negotiated features
all set up.
In addtion
addition?
Do you need me to send another version?
It's a bit easier that way but I can handle it manually too.
Let me send a new version with this fixed.
Ok, it looks like if I use git-send-email when From:tag is not me. The
patch will be sent as a attachment as spotted by Maxime.
Eli, would you please send a v3 with my acked-by? (Since I don't want to
change the author)
Thanks
If so, let's wait for Jason's reply.
Right.
to that, we take into consideration the max capability of RQT
entries early when the device is added so we don't need to take
consider
it when creating the RQT.
Last, we remove the use of mlx5_vdpa_max_qps() which just returns the
max_vas / 2 and make the code clearer.
Fixes: 52893733f2c5 ("vdpa/mlx5: Add multiqueue support")
Signed-off-by: Eli Cohen <elic@xxxxxxxxxx>
Jason I don't have your ack or S.O.B on this one.
My bad, for some reason, I miss that.
Will fix.
Thanks
---
drivers/vdpa/mlx5/net/mlx5_vnet.c | 61
+++++++++++--------------------
1 file changed, 21 insertions(+), 40 deletions(-)
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 53b8c1a68f90..61bec1ed0bc9 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -161,6 +161,7 @@ struct mlx5_vdpa_net {
struct mlx5_flow_handle *rx_rule_mcast;
bool setup;
u32 cur_num_vqs;
+ u32 rqt_size;
struct notifier_block nb;
struct vdpa_callback config_cb;
struct mlx5_vdpa_wq_ent cvq_ent;
@@ -204,17 +205,12 @@ static __virtio16 cpu_to_mlx5vdpa16(struct
mlx5_vdpa_dev *mvdev, u16 val)
return __cpu_to_virtio16(mlx5_vdpa_is_little_endian(mvdev),
val);
}
-static inline u32 mlx5_vdpa_max_qps(int max_vqs)
-{
- return max_vqs / 2;
-}
-
static u16 ctrl_vq_idx(struct mlx5_vdpa_dev *mvdev)
{
if (!(mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_MQ)))
return 2;
- return 2 * mlx5_vdpa_max_qps(mvdev->max_vqs);
+ return mvdev->max_vqs;
}
static bool is_ctrl_vq_idx(struct mlx5_vdpa_dev *mvdev, u16 idx)
@@ -1236,25 +1232,13 @@ static void teardown_vq(struct
mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *
static int create_rqt(struct mlx5_vdpa_net *ndev)
{
__be32 *list;
- int max_rqt;
void *rqtc;
int inlen;
void *in;
int i, j;
int err;
- int num;
-
- if (!(ndev->mvdev.actual_features & BIT_ULL(VIRTIO_NET_F_MQ)))
- num = 1;
- else
- num = ndev->cur_num_vqs / 2;
- max_rqt = min_t(int, roundup_pow_of_two(num),
- 1 << MLX5_CAP_GEN(ndev->mvdev.mdev, log_max_rqt_size));
- if (max_rqt < 1)
- return -EOPNOTSUPP;
-
- inlen = MLX5_ST_SZ_BYTES(create_rqt_in) + max_rqt *
MLX5_ST_SZ_BYTES(rq_num);
+ inlen = MLX5_ST_SZ_BYTES(create_rqt_in) + ndev->rqt_size *
MLX5_ST_SZ_BYTES(rq_num);
in = kzalloc(inlen, GFP_KERNEL);
if (!in)
return -ENOMEM;
@@ -1263,12 +1247,12 @@ static int create_rqt(struct mlx5_vdpa_net
*ndev)
rqtc = MLX5_ADDR_OF(create_rqt_in, in, rqt_context);
MLX5_SET(rqtc, rqtc, list_q_type,
MLX5_RQTC_LIST_Q_TYPE_VIRTIO_NET_Q);
- MLX5_SET(rqtc, rqtc, rqt_max_size, max_rqt);
+ MLX5_SET(rqtc, rqtc, rqt_max_size, ndev->rqt_size);
list = MLX5_ADDR_OF(rqtc, rqtc, rq_num[0]);
- for (i = 0, j = 0; i < max_rqt; i++, j += 2)
- list[i] = cpu_to_be32(ndev->vqs[j % (2 * num)].virtq_id);
+ for (i = 0, j = 0; i < ndev->rqt_size; i++, j += 2)
+ list[i] = cpu_to_be32(ndev->vqs[j %
ndev->cur_num_vqs].virtq_id);
- MLX5_SET(rqtc, rqtc, rqt_actual_size, max_rqt);
+ MLX5_SET(rqtc, rqtc, rqt_actual_size, ndev->rqt_size);
err = mlx5_vdpa_create_rqt(&ndev->mvdev, in, inlen,
&ndev->res.rqtn);
kfree(in);
if (err)
@@ -1282,19 +1266,13 @@ static int create_rqt(struct mlx5_vdpa_net
*ndev)
static int modify_rqt(struct mlx5_vdpa_net *ndev, int num)
{
__be32 *list;
- int max_rqt;
void *rqtc;
int inlen;
void *in;
int i, j;
int err;
- max_rqt = min_t(int, roundup_pow_of_two(ndev->cur_num_vqs / 2),
- 1 << MLX5_CAP_GEN(ndev->mvdev.mdev, log_max_rqt_size));
- if (max_rqt < 1)
- return -EOPNOTSUPP;
-
- inlen = MLX5_ST_SZ_BYTES(modify_rqt_in) + max_rqt *
MLX5_ST_SZ_BYTES(rq_num);
+ inlen = MLX5_ST_SZ_BYTES(modify_rqt_in) + ndev->rqt_size *
MLX5_ST_SZ_BYTES(rq_num);
in = kzalloc(inlen, GFP_KERNEL);
if (!in)
return -ENOMEM;
@@ -1305,10 +1283,10 @@ static int modify_rqt(struct mlx5_vdpa_net
*ndev, int num)
MLX5_SET(rqtc, rqtc, list_q_type,
MLX5_RQTC_LIST_Q_TYPE_VIRTIO_NET_Q);
list = MLX5_ADDR_OF(rqtc, rqtc, rq_num[0]);
- for (i = 0, j = 0; i < max_rqt; i++, j += 2)
+ for (i = 0, j = 0; i < ndev->rqt_size; i++, j += 2)
list[i] = cpu_to_be32(ndev->vqs[j % num].virtq_id);
- MLX5_SET(rqtc, rqtc, rqt_actual_size, max_rqt);
+ MLX5_SET(rqtc, rqtc, rqt_actual_size, ndev->rqt_size);
err = mlx5_vdpa_modify_rqt(&ndev->mvdev, in, inlen,
ndev->res.rqtn);
kfree(in);
if (err)
@@ -1582,7 +1560,7 @@ static virtio_net_ctrl_ack
handle_ctrl_mq(struct mlx5_vdpa_dev *mvdev, u8 cmd)
newqps = mlx5vdpa16_to_cpu(mvdev, mq.virtqueue_pairs);
if (newqps < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
- newqps > mlx5_vdpa_max_qps(mvdev->max_vqs))
+ newqps > ndev->rqt_size)
break;
if (ndev->cur_num_vqs == 2 * newqps) {
@@ -1946,7 +1924,7 @@ static int setup_virtqueues(struct
mlx5_vdpa_dev *mvdev)
int err;
int i;
- for (i = 0; i < 2 * mlx5_vdpa_max_qps(mvdev->max_vqs); i++) {
+ for (i = 0; i < mvdev->max_vqs; i++) {
err = setup_vq(ndev, &ndev->vqs[i]);
if (err)
goto err_vq;
@@ -2017,9 +1995,11 @@ static int
mlx5_vdpa_set_driver_features(struct vdpa_device *vdev, u64 features)
ndev->mvdev.actual_features = features &
ndev->mvdev.mlx_features;
if (ndev->mvdev.actual_features & BIT_ULL(VIRTIO_NET_F_MQ))
- ndev->cur_num_vqs = 2 * mlx5vdpa16_to_cpu(mvdev,
ndev->config.max_virtqueue_pairs);
+ ndev->rqt_size = mlx5vdpa16_to_cpu(mvdev,
ndev->config.max_virtqueue_pairs);
else
- ndev->cur_num_vqs = 2;
+ ndev->rqt_size = 1;
+
+ ndev->cur_num_vqs = 2 * ndev->rqt_size;
update_cvq_info(mvdev);
return err;
@@ -2486,7 +2466,7 @@ static void init_mvqs(struct mlx5_vdpa_net
*ndev)
struct mlx5_vdpa_virtqueue *mvq;
int i;
- for (i = 0; i < 2 * mlx5_vdpa_max_qps(ndev->mvdev.max_vqs);
++i) {
+ for (i = 0; i < ndev->mvdev.max_vqs; ++i) {
mvq = &ndev->vqs[i];
memset(mvq, 0, offsetof(struct mlx5_vdpa_virtqueue, ri));
mvq->index = i;
@@ -2606,7 +2586,8 @@ static int mlx5_vdpa_dev_add(struct
vdpa_mgmt_dev *v_mdev, const char *name,
return -EOPNOTSUPP;
}
- max_vqs = MLX5_CAP_DEV_VDPA_EMULATION(mdev,
max_num_virtio_queues);
+ max_vqs = min_t(int, MLX5_CAP_DEV_VDPA_EMULATION(mdev,
max_num_virtio_queues),
+ 1 << MLX5_CAP_GEN(mdev, log_max_rqt_size));
if (max_vqs < 2) {
dev_warn(mdev->device,
"%d virtqueues are supported. At least 2 are
required\n",
@@ -2670,7 +2651,7 @@ static int mlx5_vdpa_dev_add(struct
vdpa_mgmt_dev *v_mdev, const char *name,
ndev->mvdev.mlx_features |= BIT_ULL(VIRTIO_NET_F_MAC);
}
- config->max_virtqueue_pairs = cpu_to_mlx5vdpa16(mvdev,
mlx5_vdpa_max_qps(max_vqs));
+ config->max_virtqueue_pairs = cpu_to_mlx5vdpa16(mvdev,
max_vqs / 2);
mvdev->vdev.dma_dev = &mdev->pdev->dev;
err = mlx5_vdpa_alloc_resources(&ndev->mvdev);
if (err)
@@ -2697,7 +2678,7 @@ 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);
mvdev->vdev.mdev = &mgtdev->mgtdev;
- err = _vdpa_register_device(&mvdev->vdev, 2 *
mlx5_vdpa_max_qps(max_vqs) + 1);
+ err = _vdpa_register_device(&mvdev->vdev, max_vqs + 1);
if (err)
goto err_reg;
--
2.18.1