scsi-disk: scsi-block device for scsi pass-through should not be removable

This patch adds a new SCSI_DISK_F_NO_REMOVABLE_DEVOPS feature. By this
feature we can set that the scsi-block (scsi pass-through) device will still
be removable from the guest side, but from monitor it cannot be removed.

Cc: qemu-stable@nongnu.org
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/scsi/scsi-disk.c

@@ -63,6 +63,7 @@ typedef struct SCSIDiskReq {
 
 #define SCSI_DISK_F_REMOVABLE             0
 #define SCSI_DISK_F_DPOFUA                1
+#define SCSI_DISK_F_NO_REMOVABLE_DEVOPS   2
 
 struct SCSIDiskState
 {
@@ -2110,7 +2111,8 @@ static int scsi_initfn(SCSIDevice *dev)
         return -1;
     }
 
-    if (s->features & (1 << SCSI_DISK_F_REMOVABLE)) {
+    if ((s->features & (1 << SCSI_DISK_F_REMOVABLE)) &&
+            !(s->features & (1 << SCSI_DISK_F_NO_REMOVABLE_DEVOPS))) {
         bdrv_set_dev_ops(s->qdev.conf.bs, &scsi_disk_removable_block_ops, s);
     } else {
         bdrv_set_dev_ops(s->qdev.conf.bs, &scsi_disk_block_ops, s);
@@ -2322,6 +2324,12 @@ static int scsi_block_initfn(SCSIDevice *dev)
     } else {
         s->qdev.blocksize = 512;
     }
+
+    /* Makes the scsi-block device not removable by using HMP and QMP eject
+     * command.
+     */
+    s->features |= (1 << SCSI_DISK_F_NO_REMOVABLE_DEVOPS);
+
     return scsi_initfn(&s->qdev);
 }