[PATCH] qemu: block: Don't skip creation of 'luks' formatted images

Peter Krempa pkrempa at redhat.com
Thu Jan 23 17:05:08 UTC 2020

libvirt treats 'luks' images as raw+encryption. The logic in
qemuBlockStorageSourceCreateFormat skipped the creation if the requested
image was raw but didn't take into account the encryption.

This manifested itself e.g. when attempting to do a virsh blockcopy with
the following XML:

    <disk type='file' device='disk'>
      <driver name='qemu' type='raw'/>
      <source file='/tmp/enccpy'>
        <encryption format='luks'>
          <secret type='passphrase' uuid='0a81f5b2-8403-7b23-c8d6-21ccc2f80d6f'/>

Where qemu would report the following error:

 unable to execute QEMU command 'blockdev-add': Volume is not in LUKS format

rather than actually formatting the image first.

Signed-off-by: Peter Krempa <pkrempa at redhat.com>
 src/qemu/qemu_block.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index eab21bc107..22f03da485 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -2479,7 +2479,8 @@ qemuBlockStorageSourceCreateFormat(virDomainObjPtr vm,
     g_autoptr(virJSONValue) createformatprops = NULL;
     int ret;

-    if (src->format == VIR_STORAGE_FILE_RAW)
+    if (src->format == VIR_STORAGE_FILE_RAW &&
+        !src->encryption)
         return 0;

     if (qemuBlockStorageSourceCreateGetFormatProps(src, backingStore,

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