diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
index 4ff912dd42..da1d1d4080 100644
--- a/src/qemu/qemu_conf.c
+++ b/src/qemu/qemu_conf.c
@@ -852,14 +852,22 @@ qemuGetSharedDiskKey(const char *disk_path)
  */
 int
 qemuAddSharedDisk(virQEMUDriverPtr driver,
-                  const char *disk_path)
+                  virDomainDiskDefPtr disk)
 {
     size_t *ref = NULL;
     char *key = NULL;
     int ret = -1;
 
+    /* Currently the only conflicts we have to care about
+     * for the shared disk is "sgio" setting, which is only
+     * valid for block disk.
+     */
+    if (disk->type != VIR_DOMAIN_DISK_TYPE_BLOCK ||
+        !disk->shared || !disk->src)
+        return 0;
+
     qemuDriverLock(driver);
-    if (!(key = qemuGetSharedDiskKey(disk_path)))
+    if (!(key = qemuGetSharedDiskKey(disk->src)))
         goto cleanup;
 
     if ((ref = virHashLookup(driver->sharedDisks, key))) {
@@ -882,14 +890,18 @@ cleanup:
  */
 int
 qemuRemoveSharedDisk(virQEMUDriverPtr driver,
-                     const char *disk_path)
+                     virDomainDiskDefPtr disk)
 {
     size_t *ref = NULL;
     char *key = NULL;
     int ret = -1;
 
+    if (disk->type != VIR_DOMAIN_DISK_TYPE_BLOCK ||
+        !disk->shared || !disk->src)
+        return 0;
+
     qemuDriverLock(driver);
-    if (!(key = qemuGetSharedDiskKey(disk_path)))
+    if (!(key = qemuGetSharedDiskKey(disk->src)))
         goto cleanup;
 
     if (!(ref = virHashLookup(driver->sharedDisks, key)))
diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h
index ea4f3937eb..6ae33ae698 100644
--- a/src/qemu/qemu_conf.h
+++ b/src/qemu/qemu_conf.h
@@ -273,11 +273,11 @@ void qemuDriverCloseCallbackRunAll(virQEMUDriverPtr driver,
                                    virConnectPtr conn);
 
 int qemuAddSharedDisk(virQEMUDriverPtr driver,
-                      const char *disk_path)
+                      virDomainDiskDefPtr disk)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
 int qemuRemoveSharedDisk(virQEMUDriverPtr driver,
-                         const char *disk_path)
+                         virDomainDiskDefPtr disk)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 char * qemuGetSharedDiskKey(const char *disk_path)
     ATTRIBUTE_NONNULL(1);
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index dc35b9115b..65ab81f75e 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -5771,11 +5771,9 @@ qemuDomainAttachDeviceDiskLive(virConnectPtr conn,
     }
 
     if (ret == 0) {
-        if (disk->type == VIR_DOMAIN_DISK_TYPE_BLOCK && disk->shared) {
-            if (qemuAddSharedDisk(driver, disk->src) < 0)
-                VIR_WARN("Failed to add disk '%s' to shared disk table",
-                         disk->src);
-        }
+        if (qemuAddSharedDisk(driver, disk) < 0)
+            VIR_WARN("Failed to add disk '%s' to shared disk table",
+                     disk->src);
 
         if (qemuSetUnprivSGIO(disk) < 0)
             VIR_WARN("Failed to set unpriv_sgio of disk '%s'", disk->src);
@@ -5896,10 +5894,8 @@ qemuDomainDetachDeviceDiskLive(virQEMUDriverPtr driver,
         break;
     }
 
-    if (ret == 0 &&
-        disk->type == VIR_DOMAIN_DISK_TYPE_BLOCK &&
-        disk->shared) {
-        if (qemuRemoveSharedDisk(driver, disk->src) < 0)
+    if (ret == 0) {
+        if (qemuRemoveSharedDisk(driver, disk) < 0)
              VIR_WARN("Failed to remove disk '%s' from shared disk table",
                       disk->src);
     }
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 67362afabb..f80fe67703 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -3447,6 +3447,13 @@ qemuSetUnprivSGIO(virDomainDiskDefPtr disk)
 {
     int val = -1;
 
+    /* "sgio" is only valid for block disk; cdrom
+     * and floopy disk can have empty source.
+     */
+    if (disk->type != VIR_DOMAIN_DISK_TYPE_BLOCK ||
+        !disk->src)
+        return 0;
+
     if (disk->sgio)
         val = (disk->sgio == VIR_DOMAIN_DISK_SGIO_UNFILTERED);
 
@@ -3873,13 +3880,11 @@ int qemuProcessStart(virConnectPtr conn,
                            _("Raw I/O is not supported on this platform"));
 #endif
 
-        if (disk->type == VIR_DOMAIN_DISK_TYPE_BLOCK && disk->shared) {
-            if (qemuAddSharedDisk(driver, disk->src) < 0)
-                goto cleanup;
+        if (qemuAddSharedDisk(driver, disk) < 0)
+            goto cleanup;
 
-            if (qemuCheckSharedDisk(driver, disk) < 0)
-                goto cleanup;
-        }
+        if (qemuCheckSharedDisk(driver, disk) < 0)
+            goto cleanup;
 
         if (qemuSetUnprivSGIO(disk) < 0)
             goto cleanup;
@@ -4283,10 +4288,7 @@ void qemuProcessStop(virQEMUDriverPtr driver,
 
     for (i = 0; i < vm->def->ndisks; i++) {
         virDomainDiskDefPtr disk = vm->def->disks[i];
-
-        if (disk->type == VIR_DOMAIN_DISK_TYPE_BLOCK && disk->shared) {
-            ignore_value(qemuRemoveSharedDisk(driver, disk->src));
-        }
+        ignore_value(qemuRemoveSharedDisk(driver, disk));
     }
 
     /* Clear out dynamically assigned labels */