On Mon, Jul 5, 2021 at 3:19 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
> Virtio spec allows the device to specify the per virtqueue max queue
> size. vDPA needs to adapt to this flexibility. E.g Qemu advertise a
> small control virtqueue for virtio-net.
>
> So this patch adds a index parameter to get_vq_num_max bus operations
> for the device to report its per virtqueue max queue size.
>
> Both VHOST_VDPA_GET_VRING_NUM and VDPA_ATTR_DEV_MAX_VQ_SIZE assume a
> global maximum size. So we iterate all the virtqueues to return the
> minimal size in this case. Actually, the VHOST_VDPA_GET_VRING_NUM is
> not a must for the userspace. Userspace may choose to check the
> VHOST_SET_VRING_NUM for proving or validating the maximum virtqueue
> size. Anyway, we can invent a per vq version of
> VHOST_VDPA_GET_VRING_NUM in the future if it's necessary.
>
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> ---
> drivers/vdpa/ifcvf/ifcvf_main.c | 2 +-
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +-
> drivers/vdpa/vdpa.c | 22 +++++++++++++++++++++-
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 2 +-
> drivers/vdpa/virtio_pci/vp_vdpa.c | 2 +-
> drivers/vhost/vdpa.c | 9 ++++++---
> drivers/virtio/virtio_vdpa.c | 2 +-
> include/linux/vdpa.h | 5 ++++-
> 8 files changed, 36 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
> index ab0ab5cf0f6e..646b340db2af 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
> @@ -254,7 +254,7 @@ static void ifcvf_vdpa_set_status(struct vdpa_device *vdpa_dev, u8 status)
> ifcvf_set_status(vf, status);
> }
>
> -static u16 ifcvf_vdpa_get_vq_num_max(struct vdpa_device *vdpa_dev)
> +static u16 ifcvf_vdpa_get_vq_num_max(struct vdpa_device *vdpa_dev, u16 qid)
> {
> return IFCVF_QUEUE_MAX;
> }
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index dda5dc6f7737..afd6114d07b0 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -1584,7 +1584,7 @@ static void mlx5_vdpa_set_config_cb(struct vdpa_device *vdev, struct vdpa_callba
> }
>
> #define MLX5_VDPA_MAX_VQ_ENTRIES 256
> -static u16 mlx5_vdpa_get_vq_num_max(struct vdpa_device *vdev)
> +static u16 mlx5_vdpa_get_vq_num_max(struct vdpa_device *vdev, u16 idx)
> {
> return MLX5_VDPA_MAX_VQ_ENTRIES;
> }
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index bb3f1d1f0422..d77d59811389 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -239,6 +239,26 @@ void vdpa_unregister_driver(struct vdpa_driver *drv)
> }
> EXPORT_SYMBOL_GPL(vdpa_unregister_driver);
>
> +/**
> + * vdpa_get_vq_num_max - get the maximum virtqueue size
> + * @vdev: vdpa device
> + */
> +u16 vdpa_get_vq_num_max(struct vdpa_device *vdev)
> +{
> + const struct vdpa_config_ops *ops = vdev->config;
> + u16 s, size = ops->get_vq_num_max(vdev, 0);
> + int i;
> +
> + for (i = 1; i < vdev->nvqs; i++) {
> + s = ops->get_vq_num_max(vdev, i);
> + if (s && s < size)
> + size = s;
> + }
> +
> + return size;
> +}
> +EXPORT_SYMBOL_GPL(vdpa_get_vq_num_max);
> +
> /**
> * vdpa_mgmtdev_register - register a vdpa management device
> *
> @@ -502,7 +522,7 @@ vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq
>
> device_id = vdev->config->get_device_id(vdev);
> vendor_id = vdev->config->get_vendor_id(vdev);
> - max_vq_size = vdev->config->get_vq_num_max(vdev);
> + max_vq_size = vdpa_get_vq_num_max(vdev);
>
> err = -EMSGSIZE;
> if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev)))
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index 98f793bc9376..49e29056f164 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -422,7 +422,7 @@ static void vdpasim_set_config_cb(struct vdpa_device *vdpa,
> /* We don't support config interrupt */
> }
>
> -static u16 vdpasim_get_vq_num_max(struct vdpa_device *vdpa)
> +static u16 vdpasim_get_vq_num_max(struct vdpa_device *vdpa, u16 idx)
> {
> return VDPASIM_QUEUE_MAX;
> }
> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
> index c76ebb531212..2926641fb586 100644
> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> @@ -195,7 +195,7 @@ static void vp_vdpa_set_status(struct vdpa_device *vdpa, u8 status)
> vp_vdpa_free_irq(vp_vdpa);
> }
>
> -static u16 vp_vdpa_get_vq_num_max(struct vdpa_device *vdpa)
> +static u16 vp_vdpa_get_vq_num_max(struct vdpa_device *vdpa, u16 qid)
> {
> return VP_VDPA_QUEUE_MAX;
> }
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index fb41db3da611..c9ec395b8c42 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -289,11 +289,14 @@ static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep)
>
> static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp)
> {
> - struct vdpa_device *vdpa = v->vdpa;
> - const struct vdpa_config_ops *ops = vdpa->config;
> u16 num;
>
> - num = ops->get_vq_num_max(vdpa);
> + /*
> + * VHOST_VDPA_GET_VRING_NUM asssumes a global max virtqueue
s/asssumes/assumes. Other looks good to me.
Thanks,
Yongji
