[PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps

[Michael Qiu <qiudayu@archeros.com>]

Currently in vhost framwork, vhost_reset_device() is misnamed.
Actually, it should be vhost_reset_owner().

In vhost user, it make compatible with reset device ops, but
vhost kernel does not compatible with it, for vhost vdpa, it
only implement reset device action.

So we need seperate the function into vhost_reset_owner() and
vhost_reset_device(). So that different backend could use the
correct function.

Signde-off-by: Michael Qiu <qiudayu@archeros.com>
---
 hw/scsi/vhost-user-scsi.c         |  6 +++++-
 hw/virtio/vhost-backend.c         |  4 ++--
 hw/virtio/vhost-user.c            | 22 ++++++++++++++++++----
 include/hw/virtio/vhost-backend.h |  2 ++
 4 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
index 1b2f7ee..f179626 100644
--- a/hw/scsi/vhost-user-scsi.c
+++ b/hw/scsi/vhost-user-scsi.c
@@ -80,8 +80,12 @@ static void vhost_user_scsi_reset(VirtIODevice *vdev)
         return;
     }
 
-    if (dev->vhost_ops->vhost_reset_device) {
+    if (virtio_has_feature(dev->protocol_features,
+                           VHOST_USER_PROTOCOL_F_RESET_DEVICE) &&
+                           dev->vhost_ops->vhost_reset_device) {
         dev->vhost_ops->vhost_reset_device(dev);
+    } else if (dev->vhost_ops->vhost_reset_owner) {
+        dev->vhost_ops->vhost_reset_owner(dev);
     }
 }
 
diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
index e409a86..abbaa8b 100644
--- a/hw/virtio/vhost-backend.c
+++ b/hw/virtio/vhost-backend.c
@@ -191,7 +191,7 @@ static int vhost_kernel_set_owner(struct vhost_dev *dev)
     return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
 }
 
-static int vhost_kernel_reset_device(struct vhost_dev *dev)
+static int vhost_kernel_reset_owner(struct vhost_dev *dev)
 {
     return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
 }
@@ -317,7 +317,7 @@ const VhostOps kernel_ops = {
         .vhost_get_features = vhost_kernel_get_features,
         .vhost_set_backend_cap = vhost_kernel_set_backend_cap,
         .vhost_set_owner = vhost_kernel_set_owner,
-        .vhost_reset_device = vhost_kernel_reset_device,
+        .vhost_reset_owner = vhost_kernel_reset_owner,
         .vhost_get_vq_index = vhost_kernel_get_vq_index,
 #ifdef CONFIG_VHOST_VSOCK
         .vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid,
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 6abbc9d..4412008 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1475,16 +1475,29 @@ static int vhost_user_get_max_memslots(struct vhost_dev *dev,
     return 0;
 }
 
+static int vhost_user_reset_owner(struct vhost_dev *dev)
+{
+    VhostUserMsg msg = {
+        .hdr.request = VHOST_USER_RESET_OWNER,
+        .hdr.flags = VHOST_USER_VERSION,
+    };
+
+    return vhost_user_write(dev, &msg, NULL, 0);
+}
+
 static int vhost_user_reset_device(struct vhost_dev *dev)
 {
     VhostUserMsg msg = {
+        .hdr.request = VHOST_USER_RESET_DEVICE,
         .hdr.flags = VHOST_USER_VERSION,
     };
 
-    msg.hdr.request = virtio_has_feature(dev->protocol_features,
-                                         VHOST_USER_PROTOCOL_F_RESET_DEVICE)
-        ? VHOST_USER_RESET_DEVICE
-        : VHOST_USER_RESET_OWNER;
+    /* Caller must ensure the backend has VHOST_USER_PROTOCOL_F_RESET_DEVICE
+     * support */
+    if (!virtio_has_feature(dev->protocol_features,
+                       VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
+        return -EPERM;
+    }
 
     return vhost_user_write(dev, &msg, NULL, 0);
 }
@@ -2548,6 +2561,7 @@ const VhostOps user_ops = {
         .vhost_set_features = vhost_user_set_features,
         .vhost_get_features = vhost_user_get_features,
         .vhost_set_owner = vhost_user_set_owner,
+        .vhost_reset_owner = vhost_user_reset_owner,
         .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,
diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index 81bf310..affeeb0 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -77,6 +77,7 @@ typedef int (*vhost_get_features_op)(struct vhost_dev *dev,
                                      uint64_t *features);
 typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
 typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
+typedef int (*vhost_reset_owner_op)(struct vhost_dev *dev);
 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,
@@ -150,6 +151,7 @@ typedef struct VhostOps {
     vhost_get_features_op vhost_get_features;
     vhost_set_backend_cap_op vhost_set_backend_cap;
     vhost_set_owner_op vhost_set_owner;
+    vhost_reset_owner_op vhost_reset_owner;
     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;
-- 
1.8.3.1