On 1/9/2022 6:10 AM, Eli Cohen wrote:
On Thu, Jan 06, 2022 at 05:50:24PM -0800, Si-Wei Liu wrote:
On 1/6/2022 5:27 PM, Si-Wei Liu wrote:
On 1/5/2022 3:46 AM, Eli Cohen wrote:
Check whether the max number of data virtqueue pairs was provided when a
adding a new device and verify the new value does not exceed device
capabilities.
In addition, change the arrays holding virtqueue and callback contexts
to be dynamically allocated.
Signed-off-by: Eli Cohen <elic@xxxxxxxxxx>
---
v6 -> v7:
1. Evaluate RQT table size based on config.max_virtqueue_pairs.
drivers/vdpa/mlx5/net/mlx5_vnet.c | 51 ++++++++++++++++++++++---------
1 file changed, 37 insertions(+), 14 deletions(-)
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 4a2149f70f1e..d4720444bf78 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -131,11 +131,6 @@ struct mlx5_vdpa_virtqueue {
struct mlx5_vq_restore_info ri;
};
-/* We will remove this limitation once mlx5_vdpa_alloc_resources()
- * provides for driver space allocation
- */
-#define MLX5_MAX_SUPPORTED_VQS 16
-
static bool is_index_valid(struct mlx5_vdpa_dev *mvdev, u16 idx)
{
if (unlikely(idx > mvdev->max_idx))
@@ -148,8 +143,8 @@ struct mlx5_vdpa_net {
struct mlx5_vdpa_dev mvdev;
struct mlx5_vdpa_net_resources res;
struct virtio_net_config config;
- struct mlx5_vdpa_virtqueue vqs[MLX5_MAX_SUPPORTED_VQS];
- struct vdpa_callback event_cbs[MLX5_MAX_SUPPORTED_VQS + 1];
+ struct mlx5_vdpa_virtqueue *vqs;
+ struct vdpa_callback *event_cbs;
/* Serialize vq resources creation and destruction. This is
required
* since memory map might change and we need to destroy and create
@@ -1218,7 +1213,7 @@ static void suspend_vqs(struct mlx5_vdpa_net
*ndev)
{
int i;
- for (i = 0; i < MLX5_MAX_SUPPORTED_VQS; i++)
+ for (i = 0; i < ndev->mvdev.max_vqs; i++)
suspend_vq(ndev, &ndev->vqs[i]);
}
@@ -1244,8 +1239,14 @@ static int create_rqt(struct mlx5_vdpa_net
*ndev)
void *in;
int i, j;
int err;
+ int num;
- max_rqt = min_t(int, MLX5_MAX_SUPPORTED_VQS / 2,
+ if (!(ndev->mvdev.actual_features & BIT_ULL(VIRTIO_NET_F_MQ)))
+ num = 1;
+ else
+ num = le16_to_cpu(ndev->config.max_virtqueue_pairs);
+
+ 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;
@@ -1262,7 +1263,7 @@ static int create_rqt(struct mlx5_vdpa_net *ndev)
MLX5_SET(rqtc, rqtc, rqt_max_size, max_rqt);
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 %
ndev->mvdev.max_vqs].virtq_id);
+ list[i] = cpu_to_be32(ndev->vqs[j % (2 * num)].virtq_id);
Good catch. LGTM.
Reviewed-by: Si-Wei Liu<si-wei.liu@xxxxxxxxxx>
Apologies to reply to myself. It looks to me we need to set cur_num_vqs to
the negotiated num of queues. Otherwise any site referencing cur_num_vqs
won't work properly.
You can't really use cur_num_vqs. Consider this scenario:
create vdpa device with max VQs = 16 (RQT size created with 8 entries)
boot VM
ethtool modify num QPs to 2. cur_num_vqs now equals 2.
reboot VM.
Once VM is rebooted, the cur_num_vqs has to reset to 0 in the reset() op.
create RQT with 1 entry only.
Here cur_num_vqs will be loaded with the newly negotiated value
(max_rqt) again.
ethtool modify num QPs to 4. modify RQT will fail since it was created
with max QPs equals 1.
It won't fail as the cur_num_vqs will be consistent with the number of
queues newly negotiated (i.e the max_rqt in create_rqt) for modify.
I think it is ok to create the RQT always with the value configured when
the device was created.
The problem of not setting cur_num_vqs in create_rqt (and resetting it
in mlx5_vdpa_reset) is that, once the VM is rebooted or the device is
reset, the value doesn't go with the actual number of rqt entries hence
would break various assumptions in change_num_qps() or modify_rqt(). For
instances,
create vdpa device with max data VQs = 16
boot VM
features_ok set with MQ negotiated
RQT created with 8 entries in create_rqt
ethtool modify num QPs to 2. cur_num_vqs now equals 2.
reboot VM
features_ok set with MQ negotiated
RQT created with 8 entries in create_rqt
ethtool modify num QPs to 6.
cur_num_vqs was 2 while the actual RQT size is 8 (= 16 / 2)
change_num_qps would fail as the wrong increment branch (rather than the decrement) was taken
and this case too, which calls out the need to validate the presence of
VIRTIO_NET_F_MQ in handle_ctrl_mq()
create vdpa device with max data VQs = 16 (RQT size created with 8 entries)
boot VM
features_ok set with MQ negotiated
RQT created with 8 entries in create_rqt
ethtool modify num QPs to 2. cur_num_vqs now equals 2.
reboot VM
features_ok set with no MQ negotiated
RQT created with 8 entries in create_rqt
ethtool modify num QPs to 6. suppose guest runs a custom kernel without checking the #channels to configure
change_num_qps can succeed and no host side check prohibiting a single queue guest to set multi-queue
Thanks,
-Siwei
Further, we need to validate VIRTIO_NET_F_MQ is present
in handle_ctrl_mq() before changing the number of queue pairs.
So just disregard my previous R-b for this patch.
Thanks,
-Siwei
MLX5_SET(rqtc, rqtc, rqt_actual_size, max_rqt);
err = mlx5_vdpa_create_rqt(&ndev->mvdev, in, inlen,
&ndev->res.rqtn);
@@ -2220,7 +2221,7 @@ static int mlx5_vdpa_reset(struct vdpa_device
*vdev)
clear_vqs_ready(ndev);
mlx5_vdpa_destroy_mr(&ndev->mvdev);
ndev->mvdev.status = 0;
- memset(ndev->event_cbs, 0, sizeof(ndev->event_cbs));
+ memset(ndev->event_cbs, 0, sizeof(*ndev->event_cbs) *
(mvdev->max_vqs + 1));
ndev->mvdev.actual_features = 0;
++mvdev->generation;
if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) {
@@ -2293,6 +2294,8 @@ static void mlx5_vdpa_free(struct vdpa_device
*vdev)
}
mlx5_vdpa_free_resources(&ndev->mvdev);
mutex_destroy(&ndev->reslock);
+ kfree(ndev->event_cbs);
+ kfree(ndev->vqs);
}
static struct vdpa_notification_area
mlx5_get_vq_notification(struct vdpa_device *vdev, u16 idx)
@@ -2538,15 +2541,33 @@ static int mlx5_vdpa_dev_add(struct
vdpa_mgmt_dev *v_mdev, const char *name,
return -EOPNOTSUPP;
}
- /* we save one virtqueue for control virtqueue should we
require it */
max_vqs = MLX5_CAP_DEV_VDPA_EMULATION(mdev,
max_num_virtio_queues);
- max_vqs = min_t(u32, max_vqs, MLX5_MAX_SUPPORTED_VQS);
+ if (max_vqs < 2) {
+ dev_warn(mdev->device,
+ "%d virtqueues are supported. At least 2 are required\n",
+ max_vqs);
+ return -EAGAIN;
+ }
+
+ if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP)) {
+ if (add_config->net.max_vq_pairs > max_vqs / 2)
+ return -EINVAL;
+ max_vqs = min_t(u32, max_vqs, 2 *
add_config->net.max_vq_pairs);
+ } else {
+ max_vqs = 2;
+ }
ndev = vdpa_alloc_device(struct mlx5_vdpa_net, mvdev.vdev,
mdev->device, &mlx5_vdpa_ops,
name, false);
if (IS_ERR(ndev))
return PTR_ERR(ndev);
+ ndev->vqs = kcalloc(max_vqs, sizeof(*ndev->vqs), GFP_KERNEL);
+ ndev->event_cbs = kcalloc(max_vqs + 1,
sizeof(*ndev->event_cbs), GFP_KERNEL);
+ if (!ndev->vqs || !ndev->event_cbs) {
+ err = -ENOMEM;
+ goto err_alloc;
+ }
ndev->mvdev.max_vqs = max_vqs;
mvdev = &ndev->mvdev;
mvdev->mdev = mdev;
@@ -2627,6 +2648,7 @@ static int mlx5_vdpa_dev_add(struct
vdpa_mgmt_dev *v_mdev, const char *name,
mlx5_mpfs_del_mac(pfmdev, config->mac);
err_mtu:
mutex_destroy(&ndev->reslock);
+err_alloc:
put_device(&mvdev->vdev.dev);
return err;
}
@@ -2669,7 +2691,8 @@ static int mlx5v_probe(struct auxiliary_device
*adev,
mgtdev->mgtdev.ops = &mdev_ops;
mgtdev->mgtdev.device = mdev->device;
mgtdev->mgtdev.id_table = id_table;
- mgtdev->mgtdev.config_attr_mask =
BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR);
+ mgtdev->mgtdev.config_attr_mask =
BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR) |
+ BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP);
mgtdev->madev = madev;
err = vdpa_mgmtdev_register(&mgtdev->mgtdev);
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