vhost: move protocol_features to vhost_user

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>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260420200339.708640-5-vsementsov@yandex-team.ru>

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 */

hw/block/vhost-user-blk.c

@@ -572,10 +572,8 @@ static bool vhost_user_blk_inflight_needed(void *opaque)
 {
     struct VHostUserBlk *s = opaque;
 
-    bool inflight_migration = virtio_has_feature(s->dev.protocol_features,
-                               VHOST_USER_PROTOCOL_F_GET_VRING_BASE_INFLIGHT);
-
-    return inflight_migration;
+    return vhost_user_has_protocol_feature(
+        &s->dev, VHOST_USER_PROTOCOL_F_GET_VRING_BASE_INFLIGHT);
 }
 
 static const VMStateDescription vmstate_vhost_user_blk_inflight = {

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 */

hw/virtio/meson.build

@@ -94,6 +94,7 @@ system_virtio_ss.add_all(when: 'CONFIG_VIRTIO_PCI', if_true: virtio_pci_ss)
 
 system_ss.add_all(when: 'CONFIG_VIRTIO', if_true: system_virtio_ss)
 stub_ss.add(files('vhost-stub.c'))
+stub_ss.add(files('vhost-user-stub.c'))
 stub_ss.add(files('virtio-stub.c'))
 stub_ss.add(files('virtio-md-stubs.c'))
 

hw/virtio/vhost-user-stub.c

@@ -0,0 +1,6 @@
+#include "qemu/osdep.h"
+#include "hw/virtio/vhost-user.h"
+
+void vhost_user_qmp_status(struct vhost_dev *dev, VirtioStatus *status)
+{
+}

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"
@@ -259,6 +260,14 @@ 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 {
@@ -267,10 +276,13 @@ struct scrub_regions {
     int fd_idx;
 };
 
-static bool vhost_user_has_protocol_feature(struct vhost_dev *dev,
-                                            uint64_t feature)
+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;
+
+    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
+
+    return virtio_has_feature(u->protocol_features, feature);
 }
 
 static int vhost_user_read_header(struct vhost_dev *dev, VhostUserMsg *msg)
@@ -1338,8 +1350,8 @@ static int vhost_set_vring_file(struct vhost_dev *dev,
     int ret;
     int fds[VHOST_USER_MAX_RAM_SLOTS];
     size_t fd_num = 0;
-    bool reply_supported = virtio_has_feature(dev->protocol_features,
-                                              VHOST_USER_PROTOCOL_F_REPLY_ACK);
+    bool reply_supported =
+        vhost_user_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK);
     VhostUserMsg msg = {
         .hdr.request = request,
         .hdr.flags = VHOST_USER_VERSION,
@@ -2239,8 +2251,8 @@ 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;
@@ -3033,6 +3045,16 @@ 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,

hw/virtio/virtio-qmp.c

@@ -751,12 +751,14 @@ 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;

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,
@@ -113,4 +114,7 @@ void vhost_user_async_close(DeviceState *d,
                             CharFrontend *chardev, struct vhost_dev *vhost,
                             vu_async_close_fn cb);
 
+void vhost_user_qmp_status(struct vhost_dev *dev, VirtioStatus *status);
+bool vhost_user_has_protocol_feature(struct vhost_dev *dev, uint64_t feature);
+
 #endif

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? */