On Wed, Aug 13, 2025 at 12:53 PM Vladimir Sementsov-Ogievskiy
<[email protected]> wrote:
>
> Remove vhost-user specific hack from generic code.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]>
> ---
> hw/virtio/vhost-user.c | 8 ++++++++
> hw/virtio/vhost.c | 15 ++++++---------
> include/hw/virtio/vhost-backend.h | 2 ++
> 3 files changed, 16 insertions(+), 9 deletions(-)
>
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index 1e1d6b0d6e..1b2879a90c 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -1230,6 +1230,12 @@ static int vhost_user_set_vring_base(struct vhost_dev
> *dev,
> return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring, false);
> }
>
> +static bool vhost_user_set_vring_enable_supported(struct vhost_dev *dev)
> +{
> + return virtio_has_feature(dev->backend_features,
> + VHOST_USER_F_PROTOCOL_FEATURES);
> +}
> +
> static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
> {
> int i;
> @@ -3032,6 +3038,8 @@ const VhostOps user_ops = {
> .vhost_reset_device = vhost_user_reset_device,
> .vhost_get_vq_index = vhost_user_get_vq_index,
> .vhost_set_vring_enable = vhost_user_set_vring_enable,
> + .vhost_set_vring_enable_supported =
> + vhost_user_set_vring_enable_supported,
Why not make this a callback like vhost_user_gpu_{set|shared}_socket()
in vhost_backend.h instead?
> .vhost_requires_shm_log = vhost_user_requires_shm_log,
> .vhost_migration_done = vhost_user_migration_done,
> .vhost_net_set_mtu = vhost_user_net_set_mtu,
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 6557c58d12..c33dad4acd 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1986,15 +1986,12 @@ static int vhost_dev_set_vring_enable(struct
> vhost_dev *hdev, int enable)
> return 0;
> }
>
> - /*
> - * For vhost-user devices, if VHOST_USER_F_PROTOCOL_FEATURES has not
> - * been negotiated, the rings start directly in the enabled state, and
> - * .vhost_set_vring_enable callback will fail since
> - * VHOST_USER_SET_VRING_ENABLE is not supported.
> - */
> - if (hdev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER &&
> - !virtio_has_feature(hdev->backend_features,
> - VHOST_USER_F_PROTOCOL_FEATURES)) {
> + if (hdev->vhost_ops->vhost_set_vring_enable_supported &&
> + !hdev->vhost_ops->vhost_set_vring_enable_supported(hdev)) {
> + /*
> + * This means, that rings are always enabled, and disable/enable
> + * API is not supported.
> + */
> return 0;
> }
>
> diff --git a/include/hw/virtio/vhost-backend.h
> b/include/hw/virtio/vhost-backend.h
> index d6df209a2f..f65fa26298 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -105,6 +105,7 @@ 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_vring_enable_op)(struct vhost_dev *dev,
> int enable);
> +typedef bool (*vhost_set_vring_enable_supported_op)(struct vhost_dev *dev);
> typedef bool (*vhost_requires_shm_log_op)(struct vhost_dev *dev);
> typedef int (*vhost_migration_done_op)(struct vhost_dev *dev,
> char *mac_addr);
> @@ -193,6 +194,7 @@ typedef struct VhostOps {
> vhost_reset_device_op vhost_reset_device;
> vhost_get_vq_index_op vhost_get_vq_index;
> vhost_set_vring_enable_op vhost_set_vring_enable;
> + vhost_set_vring_enable_supported_op vhost_set_vring_enable_supported;
> vhost_requires_shm_log_op vhost_requires_shm_log;
> vhost_migration_done_op vhost_migration_done;
> vhost_vsock_set_guest_cid_op vhost_vsock_set_guest_cid;
> --
> 2.48.1
>
>
