3 files changed, 42 insertions, 3 deletions

diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index c693fc7..26f710d 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -275,6 +275,8 @@ static Property vhost_scsi_properties[] = {
     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues, 1),
     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
                        128),
+    DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSICommon, conf.seg_max_adjust,
+                      true),
     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
                        0xFFFF),
     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
index 6a6c15d..23f972d 100644
--- a/hw/scsi/vhost-user-scsi.c
+++ b/hw/scsi/vhost-user-scsi.c
@@ -39,6 +39,10 @@ static const int user_feature_bits[] = {
     VHOST_INVALID_FEATURE_BIT
 };
 
+enum VhostUserProtocolFeature {
+    VHOST_USER_PROTOCOL_F_RESET_DEVICE = 13,
+};
+
 static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
 {
     VHostUserSCSI *s = (VHostUserSCSI *)vdev;
@@ -62,6 +66,25 @@ static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
     }
 }
 
+static void vhost_user_scsi_reset(VirtIODevice *vdev)
+{
+    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(vdev);
+    struct vhost_dev *dev = &vsc->dev;
+
+    /*
+     * Historically, reset was not implemented so only reset devices
+     * that are expecting it.
+     */
+    if (!virtio_has_feature(dev->protocol_features,
+                            VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
+        return;
+    }
+
+    if (dev->vhost_ops->vhost_reset_device) {
+        dev->vhost_ops->vhost_reset_device(dev);
+    }
+}
+
 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 {
 }
@@ -182,6 +205,7 @@ static void vhost_user_scsi_class_init(ObjectClass *klass, void *data)
     vdc->get_features = vhost_scsi_common_get_features;
     vdc->set_config = vhost_scsi_common_set_config;
     vdc->set_status = vhost_user_scsi_set_status;
+    vdc->reset = vhost_user_scsi_reset;
     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
 }
 
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index e8b2b64..4bc73a3 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -597,12 +597,15 @@ bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
 {
     VirtIOSCSIReq *req, *next;
     int ret = 0;
+    bool suppress_notifications = virtio_queue_get_notification(vq);
     bool progress = false;
 
     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 
     do {
-        virtio_queue_set_notification(vq, 0);
+        if (suppress_notifications) {
+            virtio_queue_set_notification(vq, 0);
+        }
 
         while ((req = virtio_scsi_pop_req(s, vq))) {
             progress = true;
@@ -622,7 +625,9 @@ bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
             }
         }
 
-        virtio_queue_set_notification(vq, 1);
+        if (suppress_notifications) {
+            virtio_queue_set_notification(vq, 1);
+        }
     } while (ret != -EINVAL && !virtio_queue_empty(vq));
 
     QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
@@ -654,7 +659,8 @@ static void virtio_scsi_get_config(VirtIODevice *vdev,
     VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
 
     virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
-    virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
+    virtio_stl_p(vdev, &scsiconf->seg_max,
+                 s->conf.seg_max_adjust ? s->conf.virtqueue_size - 2 : 128 - 2);
     virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
     virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
     virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
@@ -893,6 +899,11 @@ void virtio_scsi_common_realize(DeviceState *dev,
         virtio_cleanup(vdev);
         return;
     }
+    if (s->conf.virtqueue_size <= 2) {
+        error_setg(errp, "invalid virtqueue_size property (= %" PRIu32 "), "
+                   "must be > 2", s->conf.virtqueue_size);
+        return;
+    }
     s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
     s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
     s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
@@ -949,6 +960,8 @@ static Property virtio_scsi_properties[] = {
     DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
     DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
                                          parent_obj.conf.virtqueue_size, 128),
+    DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI,
+                      parent_obj.conf.seg_max_adjust, true),
     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
                                                   0xFFFF),
     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,