On 4/10/20 7:18 AM, Alberto Garcia wrote:
Backing files and raw external data files are mutually exclusive.
The documentation of the raw external data bit (in autoclear_features)
already indicates that, but we should also mention it on the other
side.
Suggested-by: Eric Blake <ebl...@redhat.com>
Signed-off-by: Alberto Garcia <be...@igalia.com>
---
docs/interop/qcow2.txt | 3 +++
1 file changed, 3 insertions(+)
diff --git a/docs/interop/qcow2.txt b/docs/interop/qcow2.txt
index 640e0eca40..298a031310 100644
--- a/docs/interop/qcow2.txt
+++ b/docs/interop/qcow2.txt
@@ -25,6 +25,9 @@ The first cluster of a qcow2 image contains the file header:
is stored (NB: The string is not null terminated). 0 if
the
image doesn't have a backing file.
+ Note: backing files are incompatible with raw external data
+ files (auto-clear feature bit 1).
+
16 - 19: backing_file_size
Length of the backing file name in bytes. Must not be
longer than 1023 bytes. Undefined if the image doesn't
have
Reviewed-by: Eric Blake <ebl...@redhat.com>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org