vhost-user-common: send get_inflight_fd once

Currently the get_inflight_fd will be sent every time the device is started, and
the backend will allocate shared memory to save the inflight state. If the
backend finds that it receives the second get_inflight_fd, it will release the
previous shared memory, which breaks inflight working logic.

This patch is a preparation for the following patches.

Signed-off-by: Li Feng <fengli@smartx.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20231009044735.941655-2-fengli@smartx.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/scsi/vhost-scsi-common.c b/hw/scsi/vhost-scsi-common.c
index a06f01af262452367e1c5fe1e098d6620edf874b..a61cd0e90711f9aa28950661cea772295b296f52 100644 (file)
--- a/hw/scsi/vhost-scsi-common.c
+++ b/hw/scsi/vhost-scsi-common.c
@@ -52,20 +52,28 @@ int vhost_scsi_common_start(VHostSCSICommon *vsc)
 
     vsc->dev.acked_features = vdev->guest_features;
 
-    assert(vsc->inflight == NULL);
-    vsc->inflight = g_new0(struct vhost_inflight, 1);
-    ret = vhost_dev_get_inflight(&vsc->dev,
-                                 vs->conf.virtqueue_size,
-                                 vsc->inflight);
+    ret = vhost_dev_prepare_inflight(&vsc->dev, vdev);
     if (ret < 0) {
-        error_report("Error get inflight: %d", -ret);
+        error_report("Error setting inflight format: %d", -ret);
         goto err_guest_notifiers;
     }
 
-    ret = vhost_dev_set_inflight(&vsc->dev, vsc->inflight);
-    if (ret < 0) {
-        error_report("Error set inflight: %d", -ret);
-        goto err_guest_notifiers;
+    if (vsc->inflight) {
+        if (!vsc->inflight->addr) {
+            ret = vhost_dev_get_inflight(&vsc->dev,
+                                        vs->conf.virtqueue_size,
+                                        vsc->inflight);
+            if (ret < 0) {
+                error_report("Error getting inflight: %d", -ret);
+                goto err_guest_notifiers;
+            }
+        }
+
+        ret = vhost_dev_set_inflight(&vsc->dev, vsc->inflight);
+        if (ret < 0) {
+            error_report("Error setting inflight: %d", -ret);
+            goto err_guest_notifiers;
+        }
     }
 
     ret = vhost_dev_start(&vsc->dev, vdev, true);
@@ -85,9 +93,6 @@ int vhost_scsi_common_start(VHostSCSICommon *vsc)
     return ret;
 
 err_guest_notifiers:
-    g_free(vsc->inflight);
-    vsc->inflight = NULL;
-
     k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, false);
 err_host_notifiers:
     vhost_dev_disable_notifiers(&vsc->dev, vdev);
@@ -111,12 +116,6 @@ void vhost_scsi_common_stop(VHostSCSICommon *vsc)
     }
     assert(ret >= 0);
 
-    if (vsc->inflight) {
-        vhost_dev_free_inflight(vsc->inflight);
-        g_free(vsc->inflight);
-        vsc->inflight = NULL;
-    }
-
     vhost_dev_disable_notifiers(&vsc->dev, vdev);
 }