From d154e0bafbd51bfd029ade9f1362bdff612b0f55 Mon Sep 17 00:00:00 2001
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Fri, 16 Jul 2010 17:11:46 +0300
Subject: [PATCH] vhost: fix miration during device start

We need to know ring layout to allocate log buffer.
So init rings first.

Also fixes a theoretical memory-leak-on-error.

https://bugzilla.redhat.com/show_bug.cgi?id=615228

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/vhost.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/hw/vhost.c b/hw/vhost.c
index d37a66e0ea..65709d005d 100644
--- a/hw/vhost.c
+++ b/hw/vhost.c
@@ -659,18 +659,6 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
         r = -errno;
         goto fail;
     }
-    if (hdev->log_enabled) {
-        hdev->log_size = vhost_get_log_size(hdev);
-        hdev->log = hdev->log_size ?
-            qemu_mallocz(hdev->log_size * sizeof *hdev->log) : NULL;
-        r = ioctl(hdev->control, VHOST_SET_LOG_BASE,
-                  (uint64_t)(unsigned long)hdev->log);
-        if (r < 0) {
-            r = -errno;
-            goto fail;
-        }
-    }
-
     for (i = 0; i < hdev->nvqs; ++i) {
         r = vhost_virtqueue_init(hdev,
                                  vdev,
@@ -680,6 +668,19 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
             goto fail_vq;
         }
     }
+
+    if (hdev->log_enabled) {
+        hdev->log_size = vhost_get_log_size(hdev);
+        hdev->log = hdev->log_size ?
+            qemu_mallocz(hdev->log_size * sizeof *hdev->log) : NULL;
+        r = ioctl(hdev->control, VHOST_SET_LOG_BASE,
+                  (uint64_t)(unsigned long)hdev->log);
+        if (r < 0) {
+            r = -errno;
+            goto fail_vq;
+        }
+    }
+
     hdev->started = true;
 
     return 0;