qemu: domain: Properly setup data relevant for top disk image

qemuDomainPrepareDiskSourceChain should set up the disk zero detection
mode only for the top level image. Since it's invoked also for the
middle of the chain we need to check that it's really only the top level
image.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index e3f279f6637b5ee134fa6c517c164b9aa82f769a..5f2c99d6519c7e4473e828b5b79749270a6f6ab8 100644 (file)
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -12421,7 +12421,8 @@ qemuDomainPrepareDiskSourceChain(virDomainDiskDefPtr disk,
         src = disk->src;
 
     /* transfer properties valid only for the top level image */
-    src->detect_zeroes = disk->detect_zeroes;
+    if (src == disk->src)
+        src->detect_zeroes = disk->detect_zeroes;
 
     for (n = src; virStorageSourceIsBacking(n); n = n->backingStore) {
         if (cfg &&