vhost-user: add new vhost user messages to support virtio config space

Add VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages which can be
used for live migration of vhost user devices, also vhost user devices
can benefit from the messages to get/set virtio config space from/to the
I/O target. For the purpose to support virtio config space change,
VHOST_USER_SLAVE_CONFIG_CHANGE_MSG message is added as the event notifier
in case virtio config space change in the slave I/O target.

Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 27 insertions, 0 deletions

diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index a7a5f22bc6..592254f40d 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -20,6 +20,11 @@ typedef enum VhostBackendType {
     VHOST_BACKEND_TYPE_MAX = 3,
 } VhostBackendType;
 
+typedef enum VhostSetConfigType {
+    VHOST_SET_CONFIG_TYPE_MASTER = 0,
+    VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
+} VhostSetConfigType;
+
 struct vhost_dev;
 struct vhost_log;
 struct vhost_memory;
@@ -84,6 +89,11 @@ typedef void (*vhost_set_iotlb_callback_op)(struct vhost_dev *dev,
                                            int enabled);
 typedef int (*vhost_send_device_iotlb_msg_op)(struct vhost_dev *dev,
                                               struct vhost_iotlb_msg *imsg);
+typedef int (*vhost_set_config_op)(struct vhost_dev *dev, const uint8_t *data,
+                                   uint32_t offset, uint32_t size,
+                                   uint32_t flags);
+typedef int (*vhost_get_config_op)(struct vhost_dev *dev, uint8_t *config,
+                                   uint32_t config_len);
 
 typedef struct VhostOps {
     VhostBackendType backend_type;
@@ -118,6 +128,8 @@ typedef struct VhostOps {
     vhost_vsock_set_running_op vhost_vsock_set_running;
     vhost_set_iotlb_callback_op vhost_set_iotlb_callback;
     vhost_send_device_iotlb_msg_op vhost_send_device_iotlb_msg;
+    vhost_get_config_op vhost_get_config;
+    vhost_set_config_op vhost_set_config;
 } VhostOps;
 
 extern const VhostOps user_ops;
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 467dc7794b..1dc2d73d76 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -46,6 +46,12 @@ struct vhost_iommu {
     QLIST_ENTRY(vhost_iommu) iommu_next;
 };
 
+typedef struct VhostDevConfigOps {
+    /* Vhost device config space changed callback
+     */
+    int (*vhost_dev_config_notifier)(struct vhost_dev *dev);
+} VhostDevConfigOps;
+
 struct vhost_memory;
 struct vhost_dev {
     VirtIODevice *vdev;
@@ -76,6 +82,7 @@ struct vhost_dev {
     QLIST_ENTRY(vhost_dev) entry;
     QLIST_HEAD(, vhost_iommu) iommu_list;
     IOMMUNotifier n;
+    const VhostDevConfigOps *config_ops;
 };
 
 int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
@@ -106,4 +113,12 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
                           struct vhost_vring_file *file);
 
 int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
+int vhost_dev_get_config(struct vhost_dev *dev, uint8_t *config,
+                         uint32_t config_len);
+int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data,
+                         uint32_t offset, uint32_t size, uint32_t flags);
+/* notifier callback in case vhost device config space changed
+ */
+void vhost_dev_set_config_notifier(struct vhost_dev *dev,
+                                   const VhostDevConfigOps *ops);
 #endif