From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39611) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ffSTs-0006JX-3k for qemu-devel@nongnu.org; Tue, 17 Jul 2018 12:05:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ffSTm-0007vf-Qo for qemu-devel@nongnu.org; Tue, 17 Jul 2018 12:05:39 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:46902 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ffSTm-0007vL-DX for qemu-devel@nongnu.org; Tue, 17 Jul 2018 12:05:34 -0400 From: Markus Armbruster References: <20180706121354.2021-1-marcandre.lureau@redhat.com> <20180706121354.2021-13-marcandre.lureau@redhat.com> Date: Tue, 17 Jul 2018 18:05:31 +0200 In-Reply-To: <20180706121354.2021-13-marcandre.lureau@redhat.com> (=?utf-8?Q?=22Marc-Andr=C3=A9?= Lureau"'s message of "Fri, 6 Jul 2018 14:13:54 +0200") Message-ID: <87a7qpc0fo.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 12/12] RFC: qmp: rework 'id' handling List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau Cc: qemu-devel@nongnu.org, peterx@redhat.com, Michael Roth Copying the guest agent maintainer Michael Roth. Patch needs a rebase. Marc-Andr=C3=A9 Lureau writes: > Let qmp_dispatch() copy the 'id' field. That way any qmp client will > conform to the specification, including QGA. Before this patch, users of the common core shared by QMP and QGA have to do extra work to conform to qmp-spec.txt. QMP does, QGA doesn't. I'm inclined to consider that a bug. Judging from your description, this patch moves that work into the shared part. The patch is therefore not just a rework of 'id' handling, it's a QGA bug fix, if you're so inclined, else a QGA improvement. Thus, 1. please rephrase the commit message accordingly, and 2. the patch needs Michael's approval. > Furthermore, it > simplifies the work for qemu monitor. > > Signed-off-by: Marc-Andr=C3=A9 Lureau > --- > monitor.c | 31 ++++++++++++------------------- > qapi/qmp-dispatch.c | 10 ++++++++-- > tests/test-qga.c | 13 +++++-------- > 3 files changed, 25 insertions(+), 29 deletions(-) > > diff --git a/monitor.c b/monitor.c > index a3efe96d1d..bf192697e4 100644 > --- a/monitor.c > +++ b/monitor.c > @@ -249,8 +249,6 @@ QEMUBH *qmp_dispatcher_bh; > struct QMPRequest { > /* Owner of the request */ > Monitor *mon; > - /* "id" field of the request */ > - QObject *id; > /* > * Request object to be handled or Error to be reported > * (exactly one of them is non-null) > @@ -351,7 +349,6 @@ int monitor_read_password(Monitor *mon, ReadLineFunc = *readline_func, >=20=20 > static void qmp_request_free(QMPRequest *req) > { > - qobject_unref(req->id); > qobject_unref(req->req); > error_free(req->err); > g_free(req); > @@ -3991,18 +3988,14 @@ static int monitor_can_read(void *opaque) > * Null @rsp can only happen for commands with QCO_NO_SUCCESS_RESP. > * Nothing is emitted then. > */ > -static void monitor_qmp_respond(Monitor *mon, QDict *rsp, QObject *id) > +static void monitor_qmp_respond(Monitor *mon, QDict *rsp) > { > if (rsp) { > - if (id) { > - qdict_put_obj(rsp, "id", qobject_ref(id)); > - } > - > qmp_send_response(mon, rsp); > } > } >=20=20 > -static void monitor_qmp_dispatch(Monitor *mon, QObject *req, QObject *id) > +static void monitor_qmp_dispatch(Monitor *mon, QObject *req) > { > Monitor *old_mon; > QDict *rsp; > @@ -4027,7 +4020,7 @@ static void monitor_qmp_dispatch(Monitor *mon, QObj= ect *req, QObject *id) > } > } >=20=20 > - monitor_qmp_respond(mon, rsp, id); > + monitor_qmp_respond(mon, rsp); > qobject_unref(rsp); > } >=20=20 > @@ -4081,12 +4074,15 @@ static void monitor_qmp_bh_dispatcher(void *data) >=20=20 > need_resume =3D !qmp_oob_enabled(req_obj->mon); > if (req_obj->req) { > - trace_monitor_qmp_cmd_in_band(qobject_get_try_str(req_obj->id) ?= : ""); > - monitor_qmp_dispatch(req_obj->mon, req_obj->req, req_obj->id); > + QDict *qdict =3D qobject_to(QDict, req_obj->req); > + QObject *id =3D qdict ? qdict_get(qdict, "id") : NULL; > + trace_monitor_qmp_cmd_in_band(qobject_get_try_str(id) ?: ""); > + monitor_qmp_dispatch(req_obj->mon, req_obj->req); > } else { > assert(req_obj->err); > rsp =3D qmp_error_response(req_obj->err); > - monitor_qmp_respond(req_obj->mon, rsp, NULL); > + req_obj->err =3D NULL; > + monitor_qmp_respond(req_obj->mon, rsp); Error response without ID before and after the patch. Okay. > qobject_unref(rsp); > } >=20=20 > @@ -4115,8 +4111,7 @@ static void handle_qmp_command(JSONMessageParser *p= arser, GQueue *tokens) >=20=20 > qdict =3D qobject_to(QDict, req); > if (qdict) { > - id =3D qobject_ref(qdict_get(qdict, "id")); > - qdict_del(qdict, "id"); > + id =3D qdict_get(qdict, "id"); > } /* else will fail qmp_dispatch() */ Two users of @id remain: trace_monitor_qmp_cmd_out_of_band(), visible below, and qapi_event_send_command_dropped(). We currently plan to kill the latter. The former is guarded by if (qdict && qmp_is_oob(qdict)), and could therefore safely use qdict_get(qdict, "id"). Together, this will let us delete the whole conditional here. >=20=20 > if (trace_event_get_state_backends(TRACE_HANDLE_QMP_COMMAND)) { > @@ -4127,15 +4122,13 @@ static void handle_qmp_command(JSONMessageParser = *parser, GQueue *tokens) >=20=20 > if (qdict && qmp_is_oob(qdict)) { > /* OOB commands are executed immediately */ > - trace_monitor_qmp_cmd_out_of_band(qobject_get_try_str(id) > - ?: ""); > - monitor_qmp_dispatch(mon, req, id); > + trace_monitor_qmp_cmd_out_of_band(qobject_get_try_str(id) ?: ""); > + monitor_qmp_dispatch(mon, req); > return; > } >=20=20 > req_obj =3D g_new0(QMPRequest, 1); > req_obj->mon =3D mon; > - req_obj->id =3D id; > req_obj->req =3D req; > req_obj->err =3D err; >=20=20 > diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c > index 90ba5e3074..acea0fcfcd 100644 > --- a/qapi/qmp-dispatch.c > +++ b/qapi/qmp-dispatch.c > @@ -59,6 +59,8 @@ static QDict *qmp_dispatch_check_obj(const QObject *req= uest, bool allow_oob, > "QMP input member 'arguments' must be an obje= ct"); > return NULL; > } > + } else if (!strcmp(arg_name, "id")) { > + continue; > } else { > error_setg(errp, "QMP input member '%s' is unexpected", > arg_name); > @@ -166,8 +168,8 @@ QDict *qmp_dispatch(QmpCommandList *cmds, QObject *re= quest, > bool allow_oob) > { > Error *err =3D NULL; > - QObject *ret; > - QDict *rsp; > + QDict *rsp, *dict =3D qobject_to(QDict, request); > + QObject *ret, *id =3D dict ? qdict_get(dict, "id") : NULL; I dislike mixing initialized and uninitialized variables in the same declaration. >=20=20 > ret =3D do_qmp_dispatch(cmds, request, allow_oob, &err); >=20=20 > @@ -181,5 +183,9 @@ QDict *qmp_dispatch(QmpCommandList *cmds, QObject *re= quest, > rsp =3D NULL; > } >=20=20 > + if (rsp && id) { > + qdict_put_obj(rsp, "id", qobject_ref(id)); > + } > + > return rsp; > } This puts the ID (if any) into the response. Good. The monitor sends command responses only with monitor_qmp_respond(). It's called on two places: * monitor_qmp_dispatch() Gets its response from qmp_dispatch(), which now puts the ID (if any). * monitor_qmp_bh_dispatcher() Error response without ID before and after the patch (see above). Good. Not visible in the patch: QGA. It sends command responses only with send_response(). Called only in process_event(). Two cases: * json_parser_parse_err() sets an error Error response without ID before and after the patch * qmp_dispatch() Now puts the ID (if any). This is the externally visible change. Good. > diff --git a/tests/test-qga.c b/tests/test-qga.c > index d638b1571a..4ee8b405f4 100644 > --- a/tests/test-qga.c > +++ b/tests/test-qga.c > @@ -227,18 +227,15 @@ static void test_qga_ping(gconstpointer fix) > qobject_unref(ret); > } >=20=20 > -static void test_qga_invalid_id(gconstpointer fix) > +static void test_qga_id(gconstpointer fix) > { > const TestFixture *fixture =3D fix; > - QDict *ret, *error; > - const char *class; > + QDict *ret; >=20=20 > ret =3D qmp_fd(fixture->fd, "{'execute': 'guest-ping', 'id': 1}"); > g_assert_nonnull(ret); > - > - error =3D qdict_get_qdict(ret, "error"); > - class =3D qdict_get_try_str(error, "class"); > - g_assert_cmpstr(class, =3D=3D, "GenericError"); > + qmp_assert_no_error(ret); > + g_assert_cmpint(qdict_get_int(ret, "id"), =3D=3D, 1); >=20=20 > qobject_unref(ret); > } > @@ -1014,7 +1011,7 @@ int main(int argc, char **argv) > g_test_add_data_func("/qga/file-ops", &fix, test_qga_file_ops); > g_test_add_data_func("/qga/file-write-read", &fix, test_qga_file_wri= te_read); > g_test_add_data_func("/qga/get-time", &fix, test_qga_get_time); > - g_test_add_data_func("/qga/invalid-id", &fix, test_qga_invalid_id); > + g_test_add_data_func("/qga/id", &fix, test_qga_id); > g_test_add_data_func("/qga/invalid-oob", &fix, test_qga_invalid_oob); > g_test_add_data_func("/qga/invalid-cmd", &fix, test_qga_invalid_cmd); > g_test_add_data_func("/qga/invalid-args", &fix, test_qga_invalid_arg= s);