The functionality of -writeconfig is limited and the code
does not even try to detect cases where it prints incorrect
syntax (for example if values have a quote in them, since
qemu_config_parse does not support any kind of escaping)
so remove it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 docs/system/deprecated.rst | 7 +++++++
 softmmu/vl.c               | 1 +
 2 files changed, 8 insertions(+)

diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst
index 2fcac7861e..9aede21f11 100644
--- a/docs/system/deprecated.rst
+++ b/docs/system/deprecated.rst
@@ -146,6 +146,13 @@ library enabled as a cryptography provider.
 Neither the ``nettle`` library, or the built-in cryptography provider are
 supported on FIPS enabled hosts.
 
+``-writeconfig`` (since 6.0)
+'''''''''''''''''''''''''''''
+
+The ``-writeconfig`` option is not able to serialize the entire contents
+of the QEMU command line.  It is thus considered a failed experiment
+and deprecated.
+
 QEMU Machine Protocol (QMP) commands
 ------------------------------------
 
diff --git a/softmmu/vl.c b/softmmu/vl.c
index b219ce1f35..3e4dce2874 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -3356,6 +3356,7 @@ void qemu_init(int argc, char **argv, char **envp)
             case QEMU_OPTION_writeconfig:
                 {
                     FILE *fp;
+                    warn_report("The -writeconfig option is deprecated");
                     if (strcmp(optarg, "-") == 0) {
                         fp = stdout;
                     } else {
-- 
2.29.2

On Thu, Feb 25, 2021 at 12:11:48PM +0100, Paolo Bonzini wrote:
> The functionality of -writeconfig is limited and the code
> does not even try to detect cases where it prints incorrect
> syntax (for example if values have a quote in them, since
> qemu_config_parse does not support any kind of escaping)
> so remove it.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  docs/system/deprecated.rst | 7 +++++++
>  softmmu/vl.c               | 1 +
>  2 files changed, 8 insertions(+)
> 
> diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst
> index 2fcac7861e..9aede21f11 100644
> --- a/docs/system/deprecated.rst
> +++ b/docs/system/deprecated.rst
> @@ -146,6 +146,13 @@ library enabled as a cryptography provider.
>  Neither the ``nettle`` library, or the built-in cryptography provider are
>  supported on FIPS enabled hosts.
>  
> +``-writeconfig`` (since 6.0)
> +'''''''''''''''''''''''''''''
> +
> +The ``-writeconfig`` option is not able to serialize the entire contents
> +of the QEMU command line.  It is thus considered a failed experiment
> +and deprecated.

 s/./, with no current replacement./

> +
>  QEMU Machine Protocol (QMP) commands
>  ------------------------------------
>  
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index b219ce1f35..3e4dce2874 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -3356,6 +3356,7 @@ void qemu_init(int argc, char **argv, char **envp)
>              case QEMU_OPTION_writeconfig:
>                  {
>                      FILE *fp;
> +                    warn_report("The -writeconfig option is deprecated");

I'd suggest same here too

>                      if (strcmp(optarg, "-") == 0) {
>                          fp = stdout;
>                      } else {

Can we hide/remove it from qemu-options.hx, while still letting it be
used if people know it exists ? Failing that, at least add the deprecation
note to the qemu-options.hx help text


Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|