[Qemu-devel] [PATCH for-2.9] qom: Fix regression with 'qom-type'

[Qemu-devel] [PATCH for-2.9] qom: Fix regression with 'qom-type'

[Eric Blake]

Commit 9a6d1ac assumed that 'qom-type' could be removed from QemuOpts
with no ill effects.  However, this command line proves otherwise:

$ ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic -qmp stdio \
  -object rng-random,filename=/dev/urandom,id=rng0 \
  -device virtio-rng-pci,rng=rng0
qemu-system-x86_64: -object rng-random,filename=/dev/urandom,id=rng0: Parameter 'qom-type' is missing

Fix the regression by restoring qom-type in opts after its temporary
removal that was needed for the duration of user_creatable_add_opts().

Reported-by: Richard W. M. Jones <rjones@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
 qom/object_interfaces.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
index 9c271ad..d4253a8 100644
--- a/qom/object_interfaces.c
+++ b/qom/object_interfaces.c
@@ -122,6 +122,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
     }
     if (!id) {
         error_setg(errp, QERR_MISSING_PARAMETER, "id");
+        qemu_opt_set(opts, "qom-type", type, &error_abort);
         g_free(type);
         return NULL;
     }
@@ -134,6 +135,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
     visit_free(v);

     qemu_opts_set_id(opts, (char *) id);
+    qemu_opt_set(opts, "qom-type", type, &error_abort);
     g_free(type);
     QDECREF(pdict);
     return obj;
-- 
2.9.3

Re: [Qemu-devel] [PATCH for-2.9] qom: Fix regression with 'qom-type'

[Richard W.M. Jones]

On Thu, Mar 23, 2017 at 11:03:15AM -0500, Eric Blake wrote:
> Commit 9a6d1ac assumed that 'qom-type' could be removed from QemuOpts
> with no ill effects.  However, this command line proves otherwise:
> 
> $ ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic -qmp stdio \
>   -object rng-random,filename=/dev/urandom,id=rng0 \
>   -device virtio-rng-pci,rng=rng0
> qemu-system-x86_64: -object rng-random,filename=/dev/urandom,id=rng0: Parameter 'qom-type' is missing
> 
> Fix the regression by restoring qom-type in opts after its temporary
> removal that was needed for the duration of user_creatable_add_opts().
> 
> Reported-by: Richard W. M. Jones <rjones@redhat.com>
> Signed-off-by: Eric Blake <eblake@redhat.com>
> ---
>  qom/object_interfaces.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
> index 9c271ad..d4253a8 100644
> --- a/qom/object_interfaces.c
> +++ b/qom/object_interfaces.c
> @@ -122,6 +122,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
>      }
>      if (!id) {
>          error_setg(errp, QERR_MISSING_PARAMETER, "id");
> +        qemu_opt_set(opts, "qom-type", type, &error_abort);
>          g_free(type);
>          return NULL;
>      }
> @@ -134,6 +135,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
>      visit_free(v);
> 
>      qemu_opts_set_id(opts, (char *) id);
> +    qemu_opt_set(opts, "qom-type", type, &error_abort);
>      g_free(type);
>      QDECREF(pdict);
>      return obj;

Thanks Eric.  Yes, this fixes the problem I observed before
with libguestfs.

Tested-by: Richard W.M. Jones <rjones@redhat.com>

Rich.

-- 
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Re: [Qemu-devel] [PATCH for-2.9] qom: Fix regression with 'qom-type'

[Markus Armbruster]

Eric Blake <eblake@redhat.com> writes:

> Commit 9a6d1ac assumed that 'qom-type' could be removed from QemuOpts
> with no ill effects.  However, this command line proves otherwise:
>
> $ ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic -qmp stdio \
>   -object rng-random,filename=/dev/urandom,id=rng0 \
>   -device virtio-rng-pci,rng=rng0
> qemu-system-x86_64: -object rng-random,filename=/dev/urandom,id=rng0: Parameter 'qom-type' is missing

Shows that our test coverage is still inadequate.  Also shows that I
should do more manual testing myself.  Sorry for the inconvenience!

> Fix the regression by restoring qom-type in opts after its temporary
> removal that was needed for the duration of user_creatable_add_opts().
>
> Reported-by: Richard W. M. Jones <rjones@redhat.com>
> Signed-off-by: Eric Blake <eblake@redhat.com>
> ---
>  qom/object_interfaces.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
> index 9c271ad..d4253a8 100644
> --- a/qom/object_interfaces.c
> +++ b/qom/object_interfaces.c
> @@ -122,6 +122,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
>      }
>      if (!id) {
>          error_setg(errp, QERR_MISSING_PARAMETER, "id");
> +        qemu_opt_set(opts, "qom-type", type, &error_abort);
>          g_free(type);
>          return NULL;
>      }
> @@ -134,6 +135,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
>      visit_free(v);
>
>      qemu_opts_set_id(opts, (char *) id);
> +    qemu_opt_set(opts, "qom-type", type, &error_abort);
>      g_free(type);
>      QDECREF(pdict);
>      return obj;

The awkwardness increases a bit more, but I don't have better ideas.

Reviewed-by: Markus Armbruster <armbru@redhat.com>

Peter, can you apply this as a build fix?

Re: [Qemu-devel] [PATCH for-2.9] qom: Fix regression with 'qom-type'

[Laszlo Ersek]

On 03/23/17 17:03, Eric Blake wrote:
> Commit 9a6d1ac assumed that 'qom-type' could be removed from QemuOpts
> with no ill effects.  However, this command line proves otherwise:
> 
> $ ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic -qmp stdio \
>   -object rng-random,filename=/dev/urandom,id=rng0 \
>   -device virtio-rng-pci,rng=rng0
> qemu-system-x86_64: -object rng-random,filename=/dev/urandom,id=rng0: Parameter 'qom-type' is missing
> 
> Fix the regression by restoring qom-type in opts after its temporary
> removal that was needed for the duration of user_creatable_add_opts().
> 
> Reported-by: Richard W. M. Jones <rjones@redhat.com>
> Signed-off-by: Eric Blake <eblake@redhat.com>
> ---
>  qom/object_interfaces.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
> index 9c271ad..d4253a8 100644
> --- a/qom/object_interfaces.c
> +++ b/qom/object_interfaces.c
> @@ -122,6 +122,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
>      }
>      if (!id) {
>          error_setg(errp, QERR_MISSING_PARAMETER, "id");
> +        qemu_opt_set(opts, "qom-type", type, &error_abort);
>          g_free(type);
>          return NULL;
>      }
> @@ -134,6 +135,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
>      visit_free(v);
> 
>      qemu_opts_set_id(opts, (char *) id);
> +    qemu_opt_set(opts, "qom-type", type, &error_abort);
>      g_free(type);
>      QDECREF(pdict);
>      return obj;
> 

Tested-by: Laszlo Ersek <lersek@redhat.com>

Re: [Qemu-devel] [PATCH for-2.9] qom: Fix regression with 'qom-type'

[Peter Maydell]

On 23 March 2017 at 16:24, Markus Armbruster <armbru@redhat.com> wrote:
> Eric Blake <eblake@redhat.com> writes:
>
>> Commit 9a6d1ac assumed that 'qom-type' could be removed from QemuOpts
>> with no ill effects.  However, this command line proves otherwise:
>>
>> $ ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic -qmp stdio \
>>   -object rng-random,filename=/dev/urandom,id=rng0 \
>>   -device virtio-rng-pci,rng=rng0
>> qemu-system-x86_64: -object rng-random,filename=/dev/urandom,id=rng0: Parameter 'qom-type' is missing
>
> Shows that our test coverage is still inadequate.  Also shows that I
> should do more manual testing myself.  Sorry for the inconvenience!
>
>> Fix the regression by restoring qom-type in opts after its temporary
>> removal that was needed for the duration of user_creatable_add_opts().
>>
>> Reported-by: Richard W. M. Jones <rjones@redhat.com>
>> Signed-off-by: Eric Blake <eblake@redhat.com>
>> ---
>>  qom/object_interfaces.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
>> index 9c271ad..d4253a8 100644
>> --- a/qom/object_interfaces.c
>> +++ b/qom/object_interfaces.c
>> @@ -122,6 +122,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
>>      }
>>      if (!id) {
>>          error_setg(errp, QERR_MISSING_PARAMETER, "id");
>> +        qemu_opt_set(opts, "qom-type", type, &error_abort);
>>          g_free(type);
>>          return NULL;
>>      }
>> @@ -134,6 +135,7 @@ Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
>>      visit_free(v);
>>
>>      qemu_opts_set_id(opts, (char *) id);
>> +    qemu_opt_set(opts, "qom-type", type, &error_abort);
>>      g_free(type);
>>      QDECREF(pdict);
>>      return obj;
>
> The awkwardness increases a bit more, but I don't have better ideas.
>
> Reviewed-by: Markus Armbruster <armbru@redhat.com>
>
> Peter, can you apply this as a build fix?

Sure; applied to master.

-- PMM