[Qemu-devel] [PATCH for-2.9? v2 0/2] vl: Print warning if a non-empty default config-file is found

[Qemu-devel] [PATCH for-2.9? v2 0/2] vl: Print warning if a non-empty default config-file is found

[Eduardo Habkost]

(This missed hard freeze, but I would still like to include the
warning in 2.9 so we can remove the default config file in 2.10.
I will include this series in a pull request only if at least 2
other maintainers send their Acked-by.)

We plan to remove support for /etc/qemu/qemu.conf in the near
future. Make QEMU print a warning in case there a non-empty
/etc/qemu/qemu.conf is loaded, so users have time to adapt.

Changes v1 -> v2:
* Remove unnecessary translation of qemu_config_parse()
  erros to -EINVAL at block/blkdebug.c:read_config()
  * Suggsted-by: Markus Armbruster <armbru@redhat.com>

Eduardo Habkost (2):
  config: qemu_config_parse() return number of config groups
  vl: Print warning when a default config file is loaded

 block/blkdebug.c   |  1 -
 util/qemu-config.c | 15 +++++++--------
 vl.c               |  6 ++++++
 3 files changed, 13 insertions(+), 9 deletions(-)

-- 
2.11.0.259.g40922b1

[Qemu-devel] [PATCH for-2.9? v2 1/2] config: qemu_config_parse() return number of config groups

[Eduardo Habkost]

Change qemu_config_parse() to return the number of config groups
in success and -EINVAL on error. This will allow callers of
qemu_config_parse() to check if something was really loaded from
the config file.

All existing callers of qemu_config_parse() and
qemu_read_config_file() only check if the return value was
negative, so the change shouldn't affect them.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
Changes v1 -> v2:
* Remove unnecessary translation of qemu_config_parse()
  erros to -EINVAL at block/blkdebug.c:read_config()
  * Suggsted-by: Markus Armbruster <armbru@redhat.com>
---
 block/blkdebug.c   |  1 -
 util/qemu-config.c | 15 +++++++--------
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/block/blkdebug.c b/block/blkdebug.c
index 67e8024e36..77d747f313 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -252,7 +252,6 @@ static int read_config(BDRVBlkdebugState *s, const char *filename,
         ret = qemu_config_parse(f, config_groups, filename);
         if (ret < 0) {
             error_setg(errp, "Could not parse blkdebug config file");
-            ret = -EINVAL;
             goto fail;
         }
     }
diff --git a/util/qemu-config.c b/util/qemu-config.c
index 5527100a01..560c201bd3 100644
--- a/util/qemu-config.c
+++ b/util/qemu-config.c
@@ -379,6 +379,7 @@ void qemu_config_write(FILE *fp)
     }
 }
 
+/* Returns number of config groups on success, -errno on error */
 int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname)
 {
     char line[1024], group[64], id[64], arg[64], value[1024];
@@ -386,7 +387,8 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname)
     QemuOptsList *list = NULL;
     Error *local_err = NULL;
     QemuOpts *opts = NULL;
-    int res = -1, lno = 0;
+    int res = -EINVAL, lno = 0;
+    int count = 0;
 
     loc_push_none(&loc);
     while (fgets(line, sizeof(line), fp) != NULL) {
@@ -407,6 +409,7 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname)
                 goto out;
             }
             opts = qemu_opts_create(list, id, 1, NULL);
+            count++;
             continue;
         }
         if (sscanf(line, "[%63[^]]]", group) == 1) {
@@ -417,6 +420,7 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname)
                 goto out;
             }
             opts = qemu_opts_create(list, NULL, 0, &error_abort);
+            count++;
             continue;
         }
         value[0] = '\0';
@@ -441,7 +445,7 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname)
         error_report("error reading file");
         goto out;
     }
-    res = 0;
+    res = count;
 out:
     loc_pop(&loc);
     return res;
@@ -458,12 +462,7 @@ int qemu_read_config_file(const char *filename)
 
     ret = qemu_config_parse(f, vm_config_groups, filename);
     fclose(f);
-
-    if (ret == 0) {
-        return 0;
-    } else {
-        return -EINVAL;
-    }
+    return ret;
 }
 
 static void config_parse_qdict_section(QDict *options, QemuOptsList *opts,
-- 
2.11.0.259.g40922b1

[Qemu-devel] [PATCH for-2.9? v2 2/2] vl: Print warning when a default config file is loaded

[Eduardo Habkost]

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 -nodefconfig -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 2.9 ChangeLog.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 vl.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/vl.c b/vl.c
index 7f1644a2be..dae86fd4a8 100644
--- a/vl.c
+++ b/vl.c
@@ -2939,6 +2939,12 @@ 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;
 }
 
-- 
2.11.0.259.g40922b1

Re: [Qemu-devel] [PATCH for-2.9? v2 0/2] vl: Print warning if a non-empty default config-file is found

[Paolo Bonzini]

On 09/03/2017 19:20, Eduardo Habkost wrote:
> (This missed hard freeze, but I would still like to include the
> warning in 2.9 so we can remove the default config file in 2.10.
> I will include this series in a pull request only if at least 2
> other maintainers send their Acked-by.)
> 
> We plan to remove support for /etc/qemu/qemu.conf in the near
> future. Make QEMU print a warning in case there a non-empty
> /etc/qemu/qemu.conf is loaded, so users have time to adapt.

Thanks, it's certainly good to have this in 2.9.

Paolo

Re: [Qemu-devel] [PATCH for-2.9? v2 0/2] vl: Print warning if a non-empty default config-file is found

[Eduardo Habkost]

On Fri, Mar 10, 2017 at 10:18:26AM +0100, Paolo Bonzini wrote:
> 
> 
> On 09/03/2017 19:20, Eduardo Habkost wrote:
> > (This missed hard freeze, but I would still like to include the
> > warning in 2.9 so we can remove the default config file in 2.10.
> > I will include this series in a pull request only if at least 2
> > other maintainers send their Acked-by.)
> > 
> > We plan to remove support for /etc/qemu/qemu.conf in the near
> > future. Make QEMU print a warning in case there a non-empty
> > /etc/qemu/qemu.conf is loaded, so users have time to adapt.
> 
> Thanks, it's certainly good to have this in 2.9.

Thanks. Do you want to queue it?

-- 
Eduardo