block/rbd: Add support for rbd image encryption

Starting from ceph Pacific, RBD has built-in support for image-level encryption.
Currently supported formats are LUKS version 1 and 2.

There are 2 new relevant librbd APIs for controlling encryption, both expect an
open image context:

rbd_encryption_format: formats an image (i.e. writes the LUKS header)
rbd_encryption_load: loads encryptor/decryptor to the image IO stack

This commit extends the qemu rbd driver API to support the above.

Signed-off-by: Or Ozeri <oro@il.ibm.com>
Message-Id: <20210627114635.39326-1-oro@il.ibm.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 3114ba6..4a46552 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -128,6 +128,18 @@
   } }
 
 ##
+# @ImageInfoSpecificRbd:
+#
+# @encryption-format: Image encryption format
+#
+# Since: 6.1
+##
+{ 'struct': 'ImageInfoSpecificRbd',
+  'data': {
+      '*encryption-format': 'RbdImageEncryptionFormat'
+  } }
+
+##
 # @ImageInfoSpecific:
 #
 # A discriminated record of image format specific information structures.
@@ -141,7 +153,8 @@
       # If we need to add block driver specific parameters for
       # LUKS in future, then we'll subclass QCryptoBlockInfoLUKS
       # to define a ImageInfoSpecificLUKS
-      'luks': 'QCryptoBlockInfoLUKS'
+      'luks': 'QCryptoBlockInfoLUKS',
+      'rbd': 'ImageInfoSpecificRbd'
   } }
 
 ##
@@ -3614,6 +3627,94 @@
   'data': [ 'cephx', 'none' ] }
 
 ##
+# @RbdImageEncryptionFormat:
+#
+# Since: 6.1
+##
+{ 'enum': 'RbdImageEncryptionFormat',
+  'data': [ 'luks', 'luks2' ] }
+
+##
+# @RbdEncryptionOptionsLUKSBase:
+#
+# @key-secret: ID of a QCryptoSecret object providing a passphrase
+#              for unlocking the encryption
+#
+# Since: 6.1
+##
+{ 'struct': 'RbdEncryptionOptionsLUKSBase',
+  'data': { 'key-secret': 'str' } }
+
+##
+# @RbdEncryptionCreateOptionsLUKSBase:
+#
+# @cipher-alg: The encryption algorithm
+#
+# Since: 6.1
+##
+{ 'struct': 'RbdEncryptionCreateOptionsLUKSBase',
+  'base': 'RbdEncryptionOptionsLUKSBase',
+  'data': { '*cipher-alg': 'QCryptoCipherAlgorithm' } }
+
+##
+# @RbdEncryptionOptionsLUKS:
+#
+# Since: 6.1
+##
+{ 'struct': 'RbdEncryptionOptionsLUKS',
+  'base': 'RbdEncryptionOptionsLUKSBase',
+  'data': { } }
+
+##
+# @RbdEncryptionOptionsLUKS2:
+#
+# Since: 6.1
+##
+{ 'struct': 'RbdEncryptionOptionsLUKS2',
+  'base': 'RbdEncryptionOptionsLUKSBase',
+  'data': { } }
+
+##
+# @RbdEncryptionCreateOptionsLUKS:
+#
+# Since: 6.1
+##
+{ 'struct': 'RbdEncryptionCreateOptionsLUKS',
+  'base': 'RbdEncryptionCreateOptionsLUKSBase',
+  'data': { } }
+
+##
+# @RbdEncryptionCreateOptionsLUKS2:
+#
+# Since: 6.1
+##
+{ 'struct': 'RbdEncryptionCreateOptionsLUKS2',
+  'base': 'RbdEncryptionCreateOptionsLUKSBase',
+  'data': { } }
+
+##
+# @RbdEncryptionOptions:
+#
+# Since: 6.1
+##
+{ 'union': 'RbdEncryptionOptions',
+  'base': { 'format': 'RbdImageEncryptionFormat' },
+  'discriminator': 'format',
+  'data': { 'luks': 'RbdEncryptionOptionsLUKS',
+            'luks2': 'RbdEncryptionOptionsLUKS2' } }
+
+##
+# @RbdEncryptionCreateOptions:
+#
+# Since: 6.1
+##
+{ 'union': 'RbdEncryptionCreateOptions',
+  'base': { 'format': 'RbdImageEncryptionFormat' },
+  'discriminator': 'format',
+  'data': { 'luks': 'RbdEncryptionCreateOptionsLUKS',
+            'luks2': 'RbdEncryptionCreateOptionsLUKS2' } }
+
+##
 # @BlockdevOptionsRbd:
 #
 # @pool: Ceph pool name.
@@ -3628,6 +3729,8 @@
 #
 # @snapshot: Ceph snapshot name.
 #
+# @encrypt: Image encryption options. (Since 6.1)
+#
 # @user: Ceph id name.
 #
 # @auth-client-required: Acceptable authentication modes.
@@ -3650,6 +3753,7 @@
             'image': 'str',
             '*conf': 'str',
             '*snapshot': 'str',
+            '*encrypt': 'RbdEncryptionOptions',
             '*user': 'str',
             '*auth-client-required': ['RbdAuthMode'],
             '*key-secret': 'str',
@@ -4403,13 +4507,15 @@
 #            point to a snapshot.
 # @size: Size of the virtual disk in bytes
 # @cluster-size: RBD object size
+# @encrypt: Image encryption options. (Since 6.1)
 #
 # Since: 2.12
 ##
 { 'struct': 'BlockdevCreateOptionsRbd',
   'data': { 'location':         'BlockdevOptionsRbd',
             'size':             'size',
-            '*cluster-size' :   'size' } }
+            '*cluster-size' :   'size',
+            '*encrypt' :        'RbdEncryptionCreateOptions' } }
 
 ##
 # @BlockdevVmdkSubformat: