block: move encryption deprecation warning into qcow code

For a couple of releases we have been warning

  Encrypted images are deprecated
  Support for them will be removed in a future release.
  You can use 'qemu-img convert' to convert your image to an unencrypted one.

This warning was issued by system emulators, qemu-img, qemu-nbd
and qemu-io. Such a broad warning was issued because the original
intention was to rip out all the code for dealing with encryption
inside the QEMU block layer APIs.

The new block encryption framework used for the LUKS driver does
not rely on the unloved block layer API for encryption keys,
instead using the QOM 'secret' object type. It is thus no longer
appropriate to warn about encryption unconditionally.

When the qcow/qcow2 drivers are converted to use the new encryption
framework too, it will be practical to keep AES-CBC support present
for use in qemu-img, qemu-io & qemu-nbd to allow for interoperability
with older QEMU versions and liberation of data from existing encrypted
qcow2 files.

This change moves the warning out of the generic block code and
into the qcow/qcow2 drivers. Further, the warning is set to only
appear when running the system emulators, since qemu-img, qemu-io,
qemu-nbd are expected to support qcow2 encryption long term now that
the maint burden has been eliminated.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 8 insertions, 18 deletions

diff --git a/tests/qemu-iotests/087.out b/tests/qemu-iotests/087.out
index d0662f95e8..055c553cdb 100644
--- a/tests/qemu-iotests/087.out
+++ b/tests/qemu-iotests/087.out
@@ -38,19 +38,14 @@ QMP_VERSION
 
 === Encrypted image ===
 
-qemu-img: Encrypted images are deprecated
-Support for them will be removed in a future release.
-You can use 'qemu-img convert' to convert your image to an unencrypted one.
-qemu-img: Encrypted images are deprecated
-Support for them will be removed in a future release.
-You can use 'qemu-img convert' to convert your image to an unencrypted one.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 encryption=on
 Testing: -S
 QMP_VERSION
 {"return": {}}
-Encrypted images are deprecated
-Support for them will be removed in a future release.
-You can use 'qemu-img convert' to convert your image to an unencrypted one.
+IMGFMT built-in AES encryption is deprecated
+Support for it will be removed in a future release.
+You can use 'qemu-img convert' to switch to an
+unencrypted IMGFMT image, or a LUKS raw image.
 {"error": {"class": "GenericError", "desc": "blockdev-add doesn't support encrypted devices"}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN"}
@@ -58,9 +53,10 @@ You can use 'qemu-img convert' to convert your image to an unencrypted one.
 Testing:
 QMP_VERSION
 {"return": {}}
-Encrypted images are deprecated
-Support for them will be removed in a future release.
-You can use 'qemu-img convert' to convert your image to an unencrypted one.
+IMGFMT built-in AES encryption is deprecated
+Support for it will be removed in a future release.
+You can use 'qemu-img convert' to switch to an
+unencrypted IMGFMT image, or a LUKS raw image.
 {"error": {"class": "GenericError", "desc": "Guest must be stopped for opening of encrypted image"}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN"}
@@ -68,12 +64,6 @@ You can use 'qemu-img convert' to convert your image to an unencrypted one.
 
 === Missing driver ===
 
-qemu-img: Encrypted images are deprecated
-Support for them will be removed in a future release.
-You can use 'qemu-img convert' to convert your image to an unencrypted one.
-qemu-img: Encrypted images are deprecated
-Support for them will be removed in a future release.
-You can use 'qemu-img convert' to convert your image to an unencrypted one.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 encryption=on
 Testing: -S
 QMP_VERSION