Re: [PATCH v2 15/24] vhost-user: add op to enable or disable a single vring

[Jason Wang]

在 2022/8/16 09:06, Kangjie Xu 写道:
> The interface to set enable status for a single vring is lacked in
> VhostOps, since the vhost_set_vring_enable_op will manipulate all
> virtqueues in a device.
>
> Resetting a single vq will rely on this interface.
>
> Signed-off-by: Kangjie Xu <kangjie.xu@linux.alibaba.com>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>   hw/virtio/vhost-user.c            | 26 +++++++++++++++++++-------
>   include/hw/virtio/vhost-backend.h |  3 +++
>   2 files changed, 22 insertions(+), 7 deletions(-)
>
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index 56033f7a92..8307976cda 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -1199,6 +1199,22 @@ static int vhost_user_set_vring_base(struct vhost_dev 
> *dev,
>       return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring);
>   }
>   
> +static int vhost_user_set_single_vring_enable(struct vhost_dev *dev,
> +                                              int index,
> +                                              int enable)
> +{
> +    if (index < dev->vq_index || index >= dev->vq_index + dev->nvqs) {
> +        return -EINVAL;
> +    }
> +
> +    struct vhost_vring_state state = {
> +        .index = index,
> +        .num   = enable,
> +    };
> +
> +    return vhost_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, &state);
> +}
> +
>   static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
>   {
>       int i;
> @@ -1208,13 +1224,8 @@ static int vhost_user_set_vring_enable(struct vhost_dev 
> *dev, int enable)
>       }
>   
>       for (i = 0; i < dev->nvqs; ++i) {
> -        int ret;
> -        struct vhost_vring_state state = {
> -            .index = dev->vq_index + i,
> -            .num   = enable,
> -        };
> -
> -        ret = vhost_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, &state);


Then I'd squash this into previous patch or re-roder to let this patch 
(vhost_user_set_single_vring_enable()) to be first.

Thanks


> +        int ret = vhost_user_set_single_vring_enable(dev, dev->vq_index + i,
> +                                                     enable);
>           if (ret < 0) {
>               /*
>                * Restoring the previous state is likely infeasible, as well as
> @@ -2668,6 +2679,7 @@ const VhostOps user_ops = {
>           .vhost_reset_vring = vhost_user_reset_vring,
>           .vhost_reset_device = vhost_user_reset_device,
>           .vhost_get_vq_index = vhost_user_get_vq_index,
> +        .vhost_set_single_vring_enable = vhost_user_set_single_vring_enable,
>           .vhost_set_vring_enable = vhost_user_set_vring_enable,
>           .vhost_requires_shm_log = vhost_user_requires_shm_log,
>           .vhost_migration_done = vhost_user_migration_done,
> diff --git a/include/hw/virtio/vhost-backend.h 
> b/include/hw/virtio/vhost-backend.h
> index f23bf71a8d..38f6b752ff 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -83,6 +83,8 @@ typedef int (*vhost_reset_vring_op)(struct vhost_dev *dev,
>                                       struct vhost_vring_state *ring);
>   typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
>   typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx);
> +typedef int (*vhost_set_single_vring_enable_op)(struct vhost_dev *dev,
> +                                                int index, int enable);
>   typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
>                                            int enable);
>   typedef bool (*vhost_requires_shm_log_op)(struct vhost_dev *dev);
> @@ -158,6 +160,7 @@ typedef struct VhostOps {
>       vhost_reset_device_op vhost_reset_device;
>       vhost_reset_vring_op vhost_reset_vring;
>       vhost_get_vq_index_op vhost_get_vq_index;
> +    vhost_set_single_vring_enable_op vhost_set_single_vring_enable;
>       vhost_set_vring_enable_op vhost_set_vring_enable;
>       vhost_requires_shm_log_op vhost_requires_shm_log;
>       vhost_migration_done_op vhost_migration_done;