In case there were options set in the default config file, print
a warning so users can update their scripts.

If somebody wants to keep the config file as-is, avoid the
warning and use a command-line that will work in future QEMU
versions, they can use:

 $QEMU -no-user-config -readconfig /etc/qemu/qemu.conf

I was going to add an additional message suggesting it as a
solution, but I thought it could make it more confusing. The
solution can be documented in the QEMU 2.11 ChangeLog.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
Changes v2 -> v3:
* Rebase (no code changes)
* Commit message update: suggest -no-user-config
---
 vl.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/vl.c b/vl.c
index 4fd01fda91..888649bbd1 100644
--- a/vl.c
+++ b/vl.c
@@ -3048,6 +3048,12 @@ static int qemu_read_default_config_file(void)
         return ret;
     }
 
+    if (ret > 0) {
+        loc_set_none();
+        error_report("Warning: Future QEMU versions won't load %s automatically",
+                     CONFIG_QEMU_CONFDIR "/qemu.conf");
+    }
+
     return 0;
 }
 
-- 
2.13.5

On 09/27/2017 03:41 PM, Eduardo Habkost wrote:
> In case there were options set in the default config file, print
> a warning so users can update their scripts.
> 
> If somebody wants to keep the config file as-is, avoid the
> warning and use a command-line that will work in future QEMU
> versions, they can use:
> 
>  $QEMU -no-user-config -readconfig /etc/qemu/qemu.conf
> 
> I was going to add an additional message suggesting it as a
> solution, but I thought it could make it more confusing. The
> solution can be documented in the QEMU 2.11 ChangeLog.
> 
> Reviewed-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> Changes v2 -> v3:
> * Rebase (no code changes)
> * Commit message update: suggest -no-user-config

> +    if (ret > 0) {
> +        loc_set_none();
> +        error_report("Warning: Future QEMU versions won't load %s automatically",
> +                     CONFIG_QEMU_CONFDIR "/qemu.conf");

Shouldn't we now use warn_report() with no 'Warning:' prefix?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

On Wed, Sep 27, 2017 at 03:47:18PM -0500, Eric Blake wrote:
> On 09/27/2017 03:41 PM, Eduardo Habkost wrote:
> > In case there were options set in the default config file, print
> > a warning so users can update their scripts.
> > 
> > If somebody wants to keep the config file as-is, avoid the
> > warning and use a command-line that will work in future QEMU
> > versions, they can use:
> > 
> >  $QEMU -no-user-config -readconfig /etc/qemu/qemu.conf
> > 
> > I was going to add an additional message suggesting it as a
> > solution, but I thought it could make it more confusing. The
> > solution can be documented in the QEMU 2.11 ChangeLog.
> > 
> > Reviewed-by: Markus Armbruster <armbru@redhat.com>
> > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> > ---
> > Changes v2 -> v3:
> > * Rebase (no code changes)
> > * Commit message update: suggest -no-user-config
> 
> > +    if (ret > 0) {
> > +        loc_set_none();
> > +        error_report("Warning: Future QEMU versions won't load %s automatically",
> > +                     CONFIG_QEMU_CONFDIR "/qemu.conf");
> 
> Shouldn't we now use warn_report() with no 'Warning:' prefix?

Oops, yes.  I will fix it and send v4.

-- 
Eduardo