Support for referencing secret objects was added in

  commit b189346eb1784df95ed6fed610411dbf23d19e1f
  Author: Daniel P. Berrangé <berrange@redhat.com>
  Date:   Thu Jan 21 14:19:21 2016 +0000

    iscsi: add support for getting CHAP password via QCryptoSecret API

The existing 'password' option is overdue for deprecation and
subsequent removal.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 block/iscsi.c             |  3 +++
 docs/about/deprecated.rst | 11 +++++++++++
 2 files changed, 14 insertions(+)

diff --git a/block/iscsi.c b/block/iscsi.c
index a316d46d96..58c0623052 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -1352,6 +1352,9 @@ static void apply_chap(struct iscsi_context *iscsi, QemuOpts *opts,
     } else if (!password) {
         error_setg(errp, "CHAP username specified but no password was given");
         return;
+    } else {
+        warn_report("iSCSI block driver 'password' option is deprecated, "
+                    "use 'password-secret' instead");
     }
 
     if (iscsi_set_initiator_username_pwd(iscsi, user, password)) {
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 93affe3669..2cc8924fe9 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -267,6 +267,17 @@ Options are:
     - move backing file to NVDIMM storage and keep ``pmem=on``
       (to have NVDIMM with persistence guaranties).
 
+Block driver options
+--------------------
+
+``iscsi,password=xxx`` (since 8.0)
+''''''''''''''''''''''''''''''''''
+
+Specifying the iSCSI password in plain text on the command line using the
+``password`` option is insecure. The ``password-secret`` option should be
+used instead, to refer to a ``--object secret...`` instance that provides
+a password via a file, or encrypted.
+
 Device options
 --------------
 
-- 
2.38.1

Daniel P. Berrangé <berrange@redhat.com> writes:

> Support for referencing secret objects was added in
>
>   commit b189346eb1784df95ed6fed610411dbf23d19e1f
>   Author: Daniel P. Berrangé <berrange@redhat.com>
>   Date:   Thu Jan 21 14:19:21 2016 +0000
>
>     iscsi: add support for getting CHAP password via QCryptoSecret API
>
> The existing 'password' option is overdue for deprecation and
> subsequent removal.
>
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  block/iscsi.c             |  3 +++
>  docs/about/deprecated.rst | 11 +++++++++++
>  2 files changed, 14 insertions(+)
>
> diff --git a/block/iscsi.c b/block/iscsi.c
> index a316d46d96..58c0623052 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -1352,6 +1352,9 @@ static void apply_chap(struct iscsi_context *iscsi, QemuOpts *opts,
>      } else if (!password) {
>          error_setg(errp, "CHAP username specified but no password was given");
>          return;
> +    } else {
> +        warn_report("iSCSI block driver 'password' option is deprecated, "
> +                    "use 'password-secret' instead");
>      }
>  
>      if (iscsi_set_initiator_username_pwd(iscsi, user, password)) {
> diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
> index 93affe3669..2cc8924fe9 100644
> --- a/docs/about/deprecated.rst
> +++ b/docs/about/deprecated.rst
> @@ -267,6 +267,17 @@ Options are:
>      - move backing file to NVDIMM storage and keep ``pmem=on``
>        (to have NVDIMM with persistence guaranties).
>  
> +Block driver options
> +--------------------

I'm not sure about this headline.  For what it's worth, -help shows
-iscsi under "Block device options".

> +
> +``iscsi,password=xxx`` (since 8.0)
> +''''''''''''''''''''''''''''''''''
> +
> +Specifying the iSCSI password in plain text on the command line using the
> +``password`` option is insecure. The ``password-secret`` option should be
> +used instead, to refer to a ``--object secret...`` instance that provides
> +a password via a file, or encrypted.
> +
>  Device options
>  --------------