vhost-user-scsi: support reconnect to backend

If the backend crashes and restarts, the device is broken.
This patch adds reconnect for vhost-user-scsi.

This patch also improves the error messages, and reports some silent errors.

Tested with spdk backend.

Signed-off-by: Li Feng <fengli@smartx.com>
Message-Id: <20231009044735.941655-4-fengli@smartx.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>

1 files changed, 9 insertions, 7 deletions

diff --git a/hw/scsi/vhost-scsi-common.c b/hw/scsi/vhost-scsi-common.c
index a61cd0e..4c86370 100644
--- a/hw/scsi/vhost-scsi-common.c
+++ b/hw/scsi/vhost-scsi-common.c
@@ -16,6 +16,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "qemu/module.h"
 #include "hw/virtio/vhost.h"
@@ -25,7 +26,7 @@
 #include "hw/virtio/virtio-access.h"
 #include "hw/fw-path-provider.h"
 
-int vhost_scsi_common_start(VHostSCSICommon *vsc)
+int vhost_scsi_common_start(VHostSCSICommon *vsc, Error **errp)
 {
     int ret, i;
     VirtIODevice *vdev = VIRTIO_DEVICE(vsc);
@@ -35,18 +36,19 @@ int vhost_scsi_common_start(VHostSCSICommon *vsc)
     VirtIOSCSICommon *vs = (VirtIOSCSICommon *)vsc;
 
     if (!k->set_guest_notifiers) {
-        error_report("binding does not support guest notifiers");
+        error_setg(errp, "binding does not support guest notifiers");
         return -ENOSYS;
     }
 
     ret = vhost_dev_enable_notifiers(&vsc->dev, vdev);
     if (ret < 0) {
+        error_setg_errno(errp, -ret, "Error enabling host notifiers");
         return ret;
     }
 
     ret = k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, true);
     if (ret < 0) {
-        error_report("Error binding guest notifier");
+        error_setg_errno(errp, -ret, "Error binding guest notifier");
         goto err_host_notifiers;
     }
 
@@ -54,7 +56,7 @@ int vhost_scsi_common_start(VHostSCSICommon *vsc)
 
     ret = vhost_dev_prepare_inflight(&vsc->dev, vdev);
     if (ret < 0) {
-        error_report("Error setting inflight format: %d", -ret);
+        error_setg_errno(errp, -ret, "Error setting inflight format");
         goto err_guest_notifiers;
     }
 
@@ -64,21 +66,21 @@ int vhost_scsi_common_start(VHostSCSICommon *vsc)
                                         vs->conf.virtqueue_size,
                                         vsc->inflight);
             if (ret < 0) {
-                error_report("Error getting inflight: %d", -ret);
+                error_setg_errno(errp, -ret, "Error getting inflight");
                 goto err_guest_notifiers;
             }
         }
 
         ret = vhost_dev_set_inflight(&vsc->dev, vsc->inflight);
         if (ret < 0) {
-            error_report("Error setting inflight: %d", -ret);
+            error_setg_errno(errp, -ret, "Error setting inflight");
             goto err_guest_notifiers;
         }
     }
 
     ret = vhost_dev_start(&vsc->dev, vdev, true);
     if (ret < 0) {
-        error_report("Error start vhost dev");
+        error_setg_errno(errp, -ret, "Error starting vhost dev");
         goto err_guest_notifiers;
     }