Michael S. Tsirkin
2023-Apr-03 18:11 UTC
[PATCH 1/1] vdpa/mlx5: Support interrupt bypassing
On Mon, Apr 03, 2023 at 07:20:39PM +0300, Eli Cohen wrote:> Add support for generation of interrupts from the device directly to the > VM to the VCPU thus avoiding the overhead on the host CPU. > > When supported, the driver will attempt to allocate vectors for each > data virtqueue. If a vector for a virtqueue cannot be provided it will > use the QP mode where notifications go through the driver. > > In addition, we add a shutdown callback to make sure allocated > interrupts are released in case of shutdown to allow clean shutdown. > > Signed-off-by: Eli Cohen <elic at nvidia.com> > Signed-off-by: Saeed Mahameed <saeedm at nvidia.com> > --- > drivers/vdpa/mlx5/net/mlx5_vnet.c | 139 ++++++++++++++++++++++++++++-- > drivers/vdpa/mlx5/net/mlx5_vnet.h | 14 +++ > 2 files changed, 144 insertions(+), 9 deletions(-) > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c > index 520646ae7fa0..215a46cf8a98 100644 > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c > @@ -83,6 +83,7 @@ struct mlx5_vq_restore_info { > u64 driver_addr; > u16 avail_index; > u16 used_index; > + struct msi_map map; > bool ready; > bool restore; > }; > @@ -118,6 +119,7 @@ struct mlx5_vdpa_virtqueue { > u16 avail_idx; > u16 used_idx; > int fw_state; > + struct msi_map map; > > /* keep last in the struct */ > struct mlx5_vq_restore_info ri; > @@ -792,6 +794,13 @@ static bool counters_supported(const struct mlx5_vdpa_dev *mvdev) > BIT_ULL(MLX5_OBJ_TYPE_VIRTIO_Q_COUNTERS); > } > > +static bool msix_mode_supported(struct mlx5_vdpa_dev *mvdev) > +{ > + return (MLX5_CAP_DEV_VDPA_EMULATION(mvdev->mdev, event_mode) & > + (1 << MLX5_VIRTIO_Q_EVENT_MODE_MSIX_MODE) && > + pci_msix_can_alloc_dyn(mvdev->mdev->pdev));Don't add () around return value. too many () just obscures the logic.> +} > + > static int create_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq) > { > int inlen = MLX5_ST_SZ_BYTES(create_virtio_net_q_in); > @@ -829,9 +838,15 @@ static int create_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtque > if (vq_is_tx(mvq->index)) > MLX5_SET(virtio_net_q_object, obj_context, tisn_or_qpn, ndev->res.tisn); > > - MLX5_SET(virtio_q, vq_ctx, event_mode, MLX5_VIRTIO_Q_EVENT_MODE_QP_MODE); > + if (mvq->map.virq) { > + MLX5_SET(virtio_q, vq_ctx, event_mode, MLX5_VIRTIO_Q_EVENT_MODE_MSIX_MODE); > + MLX5_SET(virtio_q, vq_ctx, event_qpn_or_msix, mvq->map.index); > + } else { > + MLX5_SET(virtio_q, vq_ctx, event_mode, MLX5_VIRTIO_Q_EVENT_MODE_QP_MODE); > + MLX5_SET(virtio_q, vq_ctx, event_qpn_or_msix, mvq->fwqp.mqp.qpn); > + } > + > MLX5_SET(virtio_q, vq_ctx, queue_index, mvq->index); > - MLX5_SET(virtio_q, vq_ctx, event_qpn_or_msix, mvq->fwqp.mqp.qpn); > MLX5_SET(virtio_q, vq_ctx, queue_size, mvq->num_ent); > MLX5_SET(virtio_q, vq_ctx, virtio_version_1_0, > !!(ndev->mvdev.actual_features & BIT_ULL(VIRTIO_F_VERSION_1))); > @@ -1174,6 +1189,32 @@ static void counter_set_dealloc(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_vir > mlx5_vdpa_warn(&ndev->mvdev, "dealloc counter set 0x%x\n", mvq->counter_set_id); > } > > +static void alloc_vector(struct mlx5_vdpa_net *ndev, > + struct mlx5_vdpa_virtqueue *mvq) > +{ > + struct mlx5_vdpa_irq_pool *irqp = &ndev->irqp; > + int i; > + > + for (i = 0; i < irqp->num_ent; i++) { > + if (!irqp->entries[i].usecount) { > + irqp->entries[i].usecount++; > + mvq->map = irqp->entries[i].map; > + return; > + } > + } > +} > + > +static void dealloc_vector(struct mlx5_vdpa_net *ndev, > + struct mlx5_vdpa_virtqueue *mvq) > +{ > + struct mlx5_vdpa_irq_pool *irqp = &ndev->irqp; > + int i; > + > + for (i = 0; i < irqp->num_ent; i++) > + if (mvq->map.virq == irqp->entries[i].map.virq) > + irqp->entries[i].usecount--; > +} > + > static int setup_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq) > { > u16 idx = mvq->index; > @@ -1203,27 +1244,31 @@ static int setup_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq) > > err = counter_set_alloc(ndev, mvq); > if (err) > - goto err_counter; > + goto err_connect; > > + alloc_vector(ndev, mvq); > err = create_virtqueue(ndev, mvq); > if (err) > - goto err_connect; > + goto err_vq; > > if (mvq->ready) { > err = modify_virtqueue(ndev, mvq, MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY); > if (err) { > mlx5_vdpa_warn(&ndev->mvdev, "failed to modify to ready vq idx %d(%d)\n", > idx, err); > - goto err_connect; > + goto err_modify; > } > } > > mvq->initialized = true; > return 0; > > -err_connect: > +err_modify: > + destroy_virtqueue(ndev, mvq); > +err_vq: > + dealloc_vector(ndev, mvq); > counter_set_dealloc(ndev, mvq); > -err_counter: > +err_connect: > qp_destroy(ndev, &mvq->vqqp); > err_vqqp: > qp_destroy(ndev, &mvq->fwqp); > @@ -1267,6 +1312,7 @@ static void teardown_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue * > return; > > suspend_vq(ndev, mvq); > + dealloc_vector(ndev, mvq); > destroy_virtqueue(ndev, mvq); > counter_set_dealloc(ndev, mvq); > qp_destroy(ndev, &mvq->vqqp); > @@ -2374,6 +2420,7 @@ static int save_channel_info(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqu > ri->desc_addr = mvq->desc_addr; > ri->device_addr = mvq->device_addr; > ri->driver_addr = mvq->driver_addr; > + ri->map = mvq->map; > ri->restore = true; > return 0; > } > @@ -2418,6 +2465,7 @@ static void restore_channels_info(struct mlx5_vdpa_net *ndev) > mvq->desc_addr = ri->desc_addr; > mvq->device_addr = ri->device_addr; > mvq->driver_addr = ri->driver_addr; > + mvq->map = ri->map; > } > } > > @@ -2693,6 +2741,22 @@ static struct device *mlx5_get_vq_dma_dev(struct vdpa_device *vdev, u16 idx) > return mvdev->vdev.dma_dev; > } > > +static void free_irqs(struct mlx5_vdpa_net *ndev) > +{ > + struct mlx5_vdpa_irq_pool_entry *ent; > + int i; > + > + if (!msix_mode_supported(&ndev->mvdev)) > + return; > + > + for (i = ndev->irqp.num_ent - 1; i >= 0; i--) { > + ent = ndev->irqp.entries + i; > + mlx5_msix_free(ndev->mvdev.mdev, ent->map); > + ndev->irqp.num_ent--; > + } > + kfree(ndev->irqp.entries); > +} > + > static void mlx5_vdpa_free(struct vdpa_device *vdev) > { > struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev); > @@ -2708,6 +2772,7 @@ static void mlx5_vdpa_free(struct vdpa_device *vdev) > mlx5_mpfs_del_mac(pfmdev, ndev->config.mac); > } > mlx5_vdpa_free_resources(&ndev->mvdev); > + free_irqs(ndev); > kfree(ndev->event_cbs); > kfree(ndev->vqs); > } > @@ -2736,9 +2801,23 @@ static struct vdpa_notification_area mlx5_get_vq_notification(struct vdpa_device > return ret; > } > > -static int mlx5_get_vq_irq(struct vdpa_device *vdv, u16 idx) > +static int mlx5_get_vq_irq(struct vdpa_device *vdev, u16 idx) > { > - return -EOPNOTSUPP; > + struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev); > + struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev); > + struct mlx5_vdpa_virtqueue *mvq; > + > + if (!is_index_valid(mvdev, idx)) > + return -EINVAL; > + > + if (is_ctrl_vq_idx(mvdev, idx)) > + return -EOPNOTSUPP; > + > + mvq = &ndev->vqs[idx]; > + if (!mvq->map.virq) > + return -EOPNOTSUPP; > + > + return mvq->map.virq; > } > > static u64 mlx5_vdpa_get_driver_features(struct vdpa_device *vdev) > @@ -3095,6 +3174,35 @@ static int config_func_mtu(struct mlx5_core_dev *mdev, u16 mtu) > return err; > } > > +static irqreturn_t int_handler(int irq, void *nh) > +{ > + return IRQ_HANDLED; > +} > + > +static void allocate_irqs(struct mlx5_vdpa_net *ndev) > +{ > + struct mlx5_vdpa_irq_pool_entry *ent; > + int i; > + > + if (!msix_mode_supported(&ndev->mvdev)) > + return; > + > + ndev->irqp.entries = kcalloc(ndev->mvdev.max_vqs, sizeof(*ndev->irqp.entries), GFP_KERNEL); > + if (!ndev->irqp.entries) > + return; > + > + for (i = 0; i < ndev->mvdev.max_vqs; i++) { > + ent = ndev->irqp.entries + i; > + snprintf(ent->name, MLX5_VDPA_IRQ_NAME_LEN, "%s-vq-%d", > + dev_name(&ndev->mvdev.vdev.dev), i); > + ent->map = mlx5_msix_alloc(ndev->mvdev.mdev, int_handler, NULL, ent->name); > + if (!ent->map.virq) > + return; > + > + ndev->irqp.num_ent++; > + } > +} > + > static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name, > const struct vdpa_dev_set_config *add_config) > { > @@ -3171,6 +3279,7 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name, > } > > init_mvqs(ndev); > + allocate_irqs(ndev); > init_rwsem(&ndev->reslock); > config = &ndev->config; > > @@ -3358,6 +3467,17 @@ static void mlx5v_remove(struct auxiliary_device *adev) > kfree(mgtdev); > } > > +static void mlx5v_shutdown(struct auxiliary_device *auxdev) > +{ > + struct mlx5_vdpa_mgmtdev *mgtdev; > + struct mlx5_vdpa_net *ndev; > + > + mgtdev = auxiliary_get_drvdata(auxdev); > + ndev = mgtdev->ndev; > + > + free_irqs(ndev); > +} > + > static const struct auxiliary_device_id mlx5v_id_table[] = { > { .name = MLX5_ADEV_NAME ".vnet", }, > {}, > @@ -3369,6 +3489,7 @@ static struct auxiliary_driver mlx5v_driver = { > .name = "vnet", > .probe = mlx5v_probe, > .remove = mlx5v_remove, > + .shutdown = mlx5v_shutdown, > .id_table = mlx5v_id_table, > }; > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.h b/drivers/vdpa/mlx5/net/mlx5_vnet.h > index c90a89e1de4d..e5063b310d3c 100644 > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.h > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.h > @@ -26,6 +26,19 @@ static inline u16 key2vid(u64 key) > return (u16)(key >> 48) & 0xfff; > } > > +#define MLX5_VDPA_IRQ_NAME_LEN 32 > + > +struct mlx5_vdpa_irq_pool_entry { > + struct msi_map map; > + int usecount; > + char name[MLX5_VDPA_IRQ_NAME_LEN]; > +}; > + > +struct mlx5_vdpa_irq_pool { > + int num_ent; > + struct mlx5_vdpa_irq_pool_entry *entries; > +}; > + > struct mlx5_vdpa_net { > struct mlx5_vdpa_dev mvdev; > struct mlx5_vdpa_net_resources res; > @@ -49,6 +62,7 @@ struct mlx5_vdpa_net { > struct vdpa_callback config_cb; > struct mlx5_vdpa_wq_ent cvq_ent; > struct hlist_head macvlan_hash[MLX5V_MACVLAN_SIZE]; > + struct mlx5_vdpa_irq_pool irqp; > struct dentry *debugfs; > }; > > -- > 2.39.2