Reviewed-by: Raphael Norwitz <raphael.s.norwitz@gmail.com>
On Sat, Oct 11, 2025 at 7:24 PM Vladimir Sementsov-Ogievskiy
<vsementsov@yandex-team.ru> wrote:
>
> As comment says: it's only for vhost-user. So, let's move it
> to corresponding vhost backend realization.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> ---
> backends/cryptodev-vhost.c | 1 -
> hw/net/vhost_net.c | 2 --
> hw/virtio/vhost-user.c | 26 +++++++++++++++++++++++---
> hw/virtio/virtio-qmp.c | 6 ++++--
> include/hw/virtio/vhost-user.h | 3 +++
> include/hw/virtio/vhost.h | 8 --------
> 6 files changed, 30 insertions(+), 16 deletions(-)
>
> diff --git a/backends/cryptodev-vhost.c b/backends/cryptodev-vhost.c
> index abdfce33af..c6069f4e5b 100644
> --- a/backends/cryptodev-vhost.c
> +++ b/backends/cryptodev-vhost.c
> @@ -60,7 +60,6 @@ cryptodev_vhost_init(
>
> crypto->cc = options->cc;
>
> - crypto->dev.protocol_features = 0;
> crypto->backend = -1;
>
> /* vhost-user needs vq_index to initiate a specific queue pair */
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index fda90e231e..ca19983126 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -265,9 +265,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
> goto fail;
> }
> net->backend = r;
> - net->dev.protocol_features = 0;
> } else {
> - net->dev.protocol_features = 0;
> net->backend = -1;
>
> /* vhost-user needs vq_index to initiate a specific queue pair */
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index b8231dcbcf..3fd11a3b57 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -11,6 +11,7 @@
> #include "qemu/osdep.h"
> #include "qapi/error.h"
> #include "hw/virtio/virtio-dmabuf.h"
> +#include "hw/virtio/virtio-qmp.h"
> #include "hw/virtio/vhost.h"
> #include "hw/virtio/virtio-crypto.h"
> #include "hw/virtio/vhost-user.h"
> @@ -264,6 +265,14 @@ struct vhost_user {
> /* Our current regions */
> int num_shadow_regions;
> struct vhost_memory_region shadow_regions[VHOST_USER_MAX_RAM_SLOTS];
> +
> + /**
> + * @protocol_features: the vhost-user protocol feature set by
> + * VHOST_USER_SET_PROTOCOL_FEATURES. Protocol features are only
> + * negotiated if VHOST_USER_F_PROTOCOL_FEATURES has been offered
> + * by the backend (see @features).
> + */
> + uint64_t protocol_features;
> };
>
> struct scrub_regions {
> @@ -275,7 +284,8 @@ struct scrub_regions {
> static bool vhost_user_has_protocol_feature(struct vhost_dev *dev,
> uint64_t feature)
> {
> - return virtio_has_feature(dev->protocol_features, feature);
> + struct vhost_user *u = dev->opaque;
> + return virtio_has_feature(u->protocol_features, feature);
> }
>
> static int vhost_user_read_header(struct vhost_dev *dev, VhostUserMsg *msg)
> @@ -2229,8 +2239,8 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,
> }
>
> /* final set of protocol features */
> - dev->protocol_features = protocol_features;
> - err = vhost_user_set_protocol_features(dev, dev->protocol_features);
> + u->protocol_features = protocol_features;
> + err = vhost_user_set_protocol_features(dev, u->protocol_features);
> if (err < 0) {
> error_setg_errno(errp, EPROTO, "vhost_backend_init failed");
> return -EPROTO;
> @@ -3021,6 +3031,16 @@ static int vhost_user_check_device_state(struct vhost_dev *dev, Error **errp)
> return 0;
> }
>
> +void vhost_user_qmp_status(struct vhost_dev *dev, VirtioStatus *status)
> +{
> + struct vhost_user *u = dev->opaque;
> +
> + assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
> +
> + status->vhost_dev->protocol_features =
> + qmp_decode_protocols(u->protocol_features);
> +}
> +
> const VhostOps user_ops = {
> .backend_type = VHOST_BACKEND_TYPE_USER,
> .vhost_backend_init = vhost_user_backend_init,
> diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
> index dd1a38e792..82acb6d232 100644
> --- a/hw/virtio/virtio-qmp.c
> +++ b/hw/virtio/virtio-qmp.c
> @@ -821,12 +821,14 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
> status->vhost_dev->acked_features =
> qmp_decode_features(vdev->device_id, hdev->acked_features_ex);
>
> - status->vhost_dev->protocol_features =
> - qmp_decode_protocols(hdev->protocol_features);
> status->vhost_dev->max_queues = hdev->max_queues;
> status->vhost_dev->backend_cap = hdev->backend_cap;
> status->vhost_dev->log_enabled = hdev->log_enabled;
> status->vhost_dev->log_size = hdev->log_size;
> +
> + if (hdev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER) {
> + vhost_user_qmp_status(hdev, status);
> + }
> }
>
> return status;
> diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h
> index 9a3f238b43..36d96296a3 100644
> --- a/include/hw/virtio/vhost-user.h
> +++ b/include/hw/virtio/vhost-user.h
> @@ -10,6 +10,7 @@
>
> #include "chardev/char-fe.h"
> #include "hw/virtio/virtio.h"
> +#include "qapi/qapi-types-virtio.h"
>
> enum VhostUserProtocolFeature {
> VHOST_USER_PROTOCOL_F_MQ = 0,
> @@ -111,4 +112,6 @@ void vhost_user_async_close(DeviceState *d,
> CharBackend *chardev, struct vhost_dev *vhost,
> vu_async_close_fn cb);
>
> +void vhost_user_qmp_status(struct vhost_dev *dev, VirtioStatus *status);
> +
> #endif
> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> index 3e69e47833..e308bc4556 100644
> --- a/include/hw/virtio/vhost.h
> +++ b/include/hw/virtio/vhost.h
> @@ -104,14 +104,6 @@ struct vhost_dev {
> VIRTIO_DECLARE_FEATURES(features);
> VIRTIO_DECLARE_FEATURES(acked_features);
>
> - /**
> - * @protocol_features: is the vhost-user only feature set by
> - * VHOST_USER_SET_PROTOCOL_FEATURES. Protocol features are only
> - * negotiated if VHOST_USER_F_PROTOCOL_FEATURES has been offered
> - * by the backend (see @features).
> - */
> - uint64_t protocol_features;
> -
> uint64_t max_queues;
> uint64_t backend_cap;
> /* @started: is the vhost device started? */
> --
> 2.48.1
>