From b82f02e93d5efa2ea62dd135c508cb707fdd35a7 Mon Sep 17 00:00:00 2001
From: libai <libai12@huawei.com>
Date: Tue, 19 Dec 2023 20:32:00 +0800
Subject: [PATCH] vdpa: don't suspend/resume device when vdpa device not
 started

When vdpa device not started, we don't need to suspend vdpa device
and send vdpa device state information. Therefore, add the suspended
flag of vdpa device to distinguish whether the device is suspended and
use it to determine whether the device needs to resume in dest qemu.

Signed-off-by: libai <libai12@huawei.com>
---
 hw/virtio/vdpa-dev-mig.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/hw/virtio/vdpa-dev-mig.c b/hw/virtio/vdpa-dev-mig.c
index 1d299019da..887c96a201 100644
--- a/hw/virtio/vdpa-dev-mig.c
+++ b/hw/virtio/vdpa-dev-mig.c
@@ -294,10 +294,13 @@ static int vdpa_save_complete_precopy(QEMUFile *f, void *opaque)
     int ret;
 
     qemu_put_be64(f, VDPA_MIG_FLAG_DEV_CONFIG_STATE);
-    ret = vhost_vdpa_dev_buffer_save(hdev, f);
-    if (ret) {
-        error_report("Save vdpa device buffer failed: %d\n", ret);
-        return ret;
+    qemu_put_be16(f, (uint16_t)vdev->suspended);
+    if (vdev->suspended) {
+        ret = vhost_vdpa_dev_buffer_save(hdev, f);
+        if (ret) {
+            error_report("Save vdpa device buffer failed: %d\n", ret);
+            return ret;
+        }
     }
     qemu_put_be64(f, VDPA_MIG_FLAG_END_OF_STATE);
 
@@ -311,6 +314,7 @@ static int vdpa_load_state(QEMUFile *f, void *opaque, int version_id)
 
     int ret;
     uint64_t data;
+    uint16_t suspended;
 
     data = qemu_get_be64(f);
     while (data != VDPA_MIG_FLAG_END_OF_STATE) {
@@ -323,10 +327,13 @@ static int vdpa_load_state(QEMUFile *f, void *opaque, int version_id)
                 return -EINVAL;
             }
         } else if (data == VDPA_MIG_FLAG_DEV_CONFIG_STATE) {
-            ret = vhost_vdpa_dev_buffer_load(hdev, f);
-            if (ret) {
-                error_report("fail to restore device buffer.\n");
-                return ret;
+            suspended = qemu_get_be16(f);
+            if (suspended) {
+                ret = vhost_vdpa_dev_buffer_load(hdev, f);
+                if (ret) {
+                    error_report("fail to restore device buffer.\n");
+                    return ret;
+                }
             }
         }
 
-- 
2.27.0