| Message ID | 1343869374-23417-31-git-send-email-lcapitulino@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Wed, Aug 01, 2012 at 10:02:50PM -0300, Luiz Capitulino wrote: > IMPORTANT: this BREAKS qemu-ga compatibility for the error response. > > Instead of returning something like: > > { "error": { "class": "InvalidParameterValue", > "data": {"name": "mode", "expected": "halt|powerdown|reboot" } } } > > qemu-ga now returns: > > { "error": { "class": "GenericError", > "desc": "Parameter 'mode' expects halt|powerdown|reboot" } } Specific error responses weren't part of the documented API, so I think anything reliant on those is making invalid assumptions; there should always be a catch-all for unknown/unexpected error messages/error payloads. > > Notice that this is also a bug fix, as qemu-ga wasn't returning the > human message. > > Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> So, if the libvirt folks are okay with it: Acked-by: Michael Roth <mdroth@linux.vnet.ibm.com> > --- > Makefile.objs | 2 +- > qapi/qmp-core.h | 1 + > qapi/qmp-dispatch.c | 10 +++++++++- > qemu-ga.c | 4 ++-- > 4 files changed, 13 insertions(+), 4 deletions(-) > > diff --git a/Makefile.objs b/Makefile.objs > index 5ebbcfa..cbfbba5 100644 > --- a/Makefile.objs > +++ b/Makefile.objs > @@ -220,7 +220,7 @@ universal-obj-y += $(qapi-obj-y) > ###################################################################### > # guest agent > > -qga-obj-y = qga/ qemu-ga.o module.o > +qga-obj-y = qga/ qemu-ga.o module.o qapi-types.o qapi-visit.o > qga-obj-$(CONFIG_WIN32) += oslib-win32.o > qga-obj-$(CONFIG_POSIX) += oslib-posix.o qemu-sockets.o qemu-option.o > > diff --git a/qapi/qmp-core.h b/qapi/qmp-core.h > index b0f64ba..00446cf 100644 > --- a/qapi/qmp-core.h > +++ b/qapi/qmp-core.h > @@ -49,6 +49,7 @@ void qmp_disable_command(const char *name); > void qmp_enable_command(const char *name); > bool qmp_command_is_enabled(const char *name); > char **qmp_get_command_list(void); > +QObject *qmp_build_error_object(Error *errp); > > #endif > > diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c > index 122c1a2..ec613f8 100644 > --- a/qapi/qmp-dispatch.c > +++ b/qapi/qmp-dispatch.c > @@ -14,6 +14,7 @@ > #include "qemu-objects.h" > #include "qapi/qmp-core.h" > #include "json-parser.h" > +#include "qapi-types.h" > #include "error.h" > #include "error_int.h" > #include "qerror.h" > @@ -109,6 +110,13 @@ static QObject *do_qmp_dispatch(QObject *request, Error **errp) > return ret; > } > > +QObject *qmp_build_error_object(Error *errp) > +{ > + return qobject_from_jsonf("{ 'class': %s, 'desc': %s }", > + ErrorClass_lookup[error_get_class(errp)], > + error_get_pretty(errp)); > +} > + > QObject *qmp_dispatch(QObject *request) > { > Error *err = NULL; > @@ -119,7 +127,7 @@ QObject *qmp_dispatch(QObject *request) > > rsp = qdict_new(); > if (err) { > - qdict_put_obj(rsp, "error", error_get_qobject(err)); > + qdict_put_obj(rsp, "error", qmp_build_error_object(err)); > error_free(err); > } else if (ret) { > qdict_put_obj(rsp, "return", ret); > diff --git a/qemu-ga.c b/qemu-ga.c > index 8199da7..f45bc61 100644 > --- a/qemu-ga.c > +++ b/qemu-ga.c > @@ -515,7 +515,7 @@ static void process_event(JSONMessageParser *parser, QList *tokens) > } else { > g_warning("failed to parse event: %s", error_get_pretty(err)); > } > - qdict_put_obj(qdict, "error", error_get_qobject(err)); > + qdict_put_obj(qdict, "error", qmp_build_error_object(err)); > error_free(err); > } else { > qdict = qobject_to_qdict(obj); > @@ -532,7 +532,7 @@ static void process_event(JSONMessageParser *parser, QList *tokens) > qdict = qdict_new(); > g_warning("unrecognized payload format"); > error_set(&err, QERR_UNSUPPORTED); > - qdict_put_obj(qdict, "error", error_get_qobject(err)); > + qdict_put_obj(qdict, "error", qmp_build_error_object(err)); > error_free(err); > } > ret = send_response(s, QOBJECT(qdict)); > -- > 1.7.11.2.249.g31c7954.dirty >
On 08/03/2012 11:44 AM, Michael Roth wrote: > On Wed, Aug 01, 2012 at 10:02:50PM -0300, Luiz Capitulino wrote: >> IMPORTANT: this BREAKS qemu-ga compatibility for the error response. >> >> Instead of returning something like: >> >> { "error": { "class": "InvalidParameterValue", >> "data": {"name": "mode", "expected": "halt|powerdown|reboot" } } } >> >> qemu-ga now returns: >> >> { "error": { "class": "GenericError", >> "desc": "Parameter 'mode' expects halt|powerdown|reboot" } } > >> >> Notice that this is also a bug fix, as qemu-ga wasn't returning the >> human message. >> >> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> > > So, if the libvirt folks are okay with it: The only use libvirt made of existing qemu-ga errors was to stringify them in order to pass on an error message to the user when a command failed. Existing libvirt attempts to look up the 'desc' field, and when it is lacking, then attempts to stringify the 'class' field based on a finite list of known classes. Qemu is now shrinking the list of known classes but providing a 'desc' field, so the error message quality in libvirt will actually improve. After reading libvirt's src/qemu/qemu_agent.c, I don't see any problem with this patch from libvirt's point of view. Reviewed-by: Eric Blake <eblake@redhat.com>
On Fri, 03 Aug 2012 11:56:29 -0600 Eric Blake <eblake@redhat.com> wrote: > On 08/03/2012 11:44 AM, Michael Roth wrote: > > On Wed, Aug 01, 2012 at 10:02:50PM -0300, Luiz Capitulino wrote: > >> IMPORTANT: this BREAKS qemu-ga compatibility for the error response. > >> > >> Instead of returning something like: > >> > >> { "error": { "class": "InvalidParameterValue", > >> "data": {"name": "mode", "expected": "halt|powerdown|reboot" } } } > >> > >> qemu-ga now returns: > >> > >> { "error": { "class": "GenericError", > >> "desc": "Parameter 'mode' expects halt|powerdown|reboot" } } > > > > >> > >> Notice that this is also a bug fix, as qemu-ga wasn't returning the > >> human message. > >> > >> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> > > > > So, if the libvirt folks are okay with it: > > The only use libvirt made of existing qemu-ga errors was to stringify > them in order to pass on an error message to the user when a command > failed. Existing libvirt attempts to look up the 'desc' field, and when > it is lacking, then attempts to stringify the 'class' field based on a > finite list of known classes. Qemu is now shrinking the list of known > classes but providing a 'desc' field, so the error message quality in > libvirt will actually improve. After reading libvirt's > src/qemu/qemu_agent.c, I don't see any problem with this patch from > libvirt's point of view. Yeah, I actually have a request from Michal to do just that (add 'desc' to qemu-ga's errors). > > Reviewed-by: Eric Blake <eblake@redhat.com> > >
diff --git a/Makefile.objs b/Makefile.objs index 5ebbcfa..cbfbba5 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -220,7 +220,7 @@ universal-obj-y += $(qapi-obj-y) ###################################################################### # guest agent -qga-obj-y = qga/ qemu-ga.o module.o +qga-obj-y = qga/ qemu-ga.o module.o qapi-types.o qapi-visit.o qga-obj-$(CONFIG_WIN32) += oslib-win32.o qga-obj-$(CONFIG_POSIX) += oslib-posix.o qemu-sockets.o qemu-option.o diff --git a/qapi/qmp-core.h b/qapi/qmp-core.h index b0f64ba..00446cf 100644 --- a/qapi/qmp-core.h +++ b/qapi/qmp-core.h @@ -49,6 +49,7 @@ void qmp_disable_command(const char *name); void qmp_enable_command(const char *name); bool qmp_command_is_enabled(const char *name); char **qmp_get_command_list(void); +QObject *qmp_build_error_object(Error *errp); #endif diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c index 122c1a2..ec613f8 100644 --- a/qapi/qmp-dispatch.c +++ b/qapi/qmp-dispatch.c @@ -14,6 +14,7 @@ #include "qemu-objects.h" #include "qapi/qmp-core.h" #include "json-parser.h" +#include "qapi-types.h" #include "error.h" #include "error_int.h" #include "qerror.h" @@ -109,6 +110,13 @@ static QObject *do_qmp_dispatch(QObject *request, Error **errp) return ret; } +QObject *qmp_build_error_object(Error *errp) +{ + return qobject_from_jsonf("{ 'class': %s, 'desc': %s }", + ErrorClass_lookup[error_get_class(errp)], + error_get_pretty(errp)); +} + QObject *qmp_dispatch(QObject *request) { Error *err = NULL; @@ -119,7 +127,7 @@ QObject *qmp_dispatch(QObject *request) rsp = qdict_new(); if (err) { - qdict_put_obj(rsp, "error", error_get_qobject(err)); + qdict_put_obj(rsp, "error", qmp_build_error_object(err)); error_free(err); } else if (ret) { qdict_put_obj(rsp, "return", ret); diff --git a/qemu-ga.c b/qemu-ga.c index 8199da7..f45bc61 100644 --- a/qemu-ga.c +++ b/qemu-ga.c @@ -515,7 +515,7 @@ static void process_event(JSONMessageParser *parser, QList *tokens) } else { g_warning("failed to parse event: %s", error_get_pretty(err)); } - qdict_put_obj(qdict, "error", error_get_qobject(err)); + qdict_put_obj(qdict, "error", qmp_build_error_object(err)); error_free(err); } else { qdict = qobject_to_qdict(obj); @@ -532,7 +532,7 @@ static void process_event(JSONMessageParser *parser, QList *tokens) qdict = qdict_new(); g_warning("unrecognized payload format"); error_set(&err, QERR_UNSUPPORTED); - qdict_put_obj(qdict, "error", error_get_qobject(err)); + qdict_put_obj(qdict, "error", qmp_build_error_object(err)); error_free(err); } ret = send_response(s, QOBJECT(qdict));
IMPORTANT: this BREAKS qemu-ga compatibility for the error response. Instead of returning something like: { "error": { "class": "InvalidParameterValue", "data": {"name": "mode", "expected": "halt|powerdown|reboot" } } } qemu-ga now returns: { "error": { "class": "GenericError", "desc": "Parameter 'mode' expects halt|powerdown|reboot" } } Notice that this is also a bug fix, as qemu-ga wasn't returning the human message. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> --- Makefile.objs | 2 +- qapi/qmp-core.h | 1 + qapi/qmp-dispatch.c | 10 +++++++++- qemu-ga.c | 4 ++-- 4 files changed, 13 insertions(+), 4 deletions(-)