Michael S. Tsirkin
2022-May-16 08:22 UTC
[PATCH RESEND V3 3/3] vdpa/mlx5: Use consistent RQT size
On Mon, May 16, 2022 at 08:17:18AM +0000, Eli Cohen wrote:> Hi Michael, > > When are you going to pull this fix? > It fixes a real problem and was reviewed and acked.Do I understand it correctly that this is a stand-alone patch? Sorry, my process have been thrown off by it being labeled 3/3 but not being part of a thread. Do not do this for single patches please. And I suspect 0-day machinery didn't process it either. Can you repost as a stand-along patch please? I will then process ASAP. Thanks!> > -----Original Message----- > > From: Eli Cohen <elic at nvidia.com> > > Sent: Wednesday, April 6, 2022 11:53 AM > > To: mst at redhat.com; jasowang at redhat.com > > Cc: hdanton at sina.com; virtualization at lists.linux-foundation.org; linux-kernel at vger.kernel.org; Eli Cohen <elic at nvidia.com> > > Subject: [PATCH RESEND V3 3/3] vdpa/mlx5: Use consistent RQT size > > > > 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 addition 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") > > Acked-by: Jason Wang <jasowang at redhat.com> > > Signed-off-by: Eli Cohen <elic at nvidia.com> > > --- > > V2 -> V3: > > Fix typo in change log > > Add acked-by Jason > > > > 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 79001301b383..e0de44000d92 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) > > @@ -1625,7 +1603,7 @@ 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) { > > @@ -1989,7 +1967,7 @@ 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; > > @@ -2060,9 +2038,11 @@ 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; > > @@ -2529,7 +2509,7 @@ 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; > > @@ -2671,7 +2651,8 @@ 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", > > @@ -2742,7 +2723,7 @@ 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) > > @@ -2769,7 +2750,7 @@ 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; > > > > -- > > 2.35.1