| Message ID | 20210924090427.9218-7-kwolf@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | qdev: Add JSON -device and fix QMP device_add | expand |
24.09.2021 12:04, Kevin Wolf wrote: > object_property_add_child() fails (with &error_abort) if an object with > the same name already exists. As long as QemuOpts is in use for -device > and device_add, it catches duplicate IDs before qdev_set_id() is even > called. However, for enabling non-QemuOpts code paths, we need to make > sure that the condition doesn't cause a crash, but fails gracefully. > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > --- > include/monitor/qdev.h | 2 +- > hw/xen/xen-legacy-backend.c | 3 ++- > softmmu/qdev-monitor.c | 16 ++++++++++------ > 3 files changed, 13 insertions(+), 8 deletions(-) > > diff --git a/include/monitor/qdev.h b/include/monitor/qdev.h > index 389287eb44..7961308c75 100644 > --- a/include/monitor/qdev.h > +++ b/include/monitor/qdev.h > @@ -9,6 +9,6 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp); > > int qdev_device_help(QemuOpts *opts); > DeviceState *qdev_device_add(QemuOpts *opts, Error **errp); > -void qdev_set_id(DeviceState *dev, char *id); > +void qdev_set_id(DeviceState *dev, char *id, Error **errp); > > #endif > diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c > index dd8ae1452d..17aca85ddc 100644 > --- a/hw/xen/xen-legacy-backend.c > +++ b/hw/xen/xen-legacy-backend.c > @@ -276,7 +276,8 @@ static struct XenLegacyDevice *xen_be_get_xendev(const char *type, int dom, > xendev = g_malloc0(ops->size); > object_initialize(&xendev->qdev, ops->size, TYPE_XENBACKEND); > OBJECT(xendev)->free = g_free; > - qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev)); > + qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev), > + &error_abort); > qdev_realize(DEVICE(xendev), xen_sysbus, &error_fatal); > object_unref(OBJECT(xendev)); > > diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c > index 1207e57a46..c2af906df0 100644 > --- a/softmmu/qdev-monitor.c > +++ b/softmmu/qdev-monitor.c > @@ -593,26 +593,27 @@ static BusState *qbus_find(const char *path, Error **errp) > } > > /* Takes ownership of @id, will be freed when deleting the device */ > -void qdev_set_id(DeviceState *dev, char *id) > +void qdev_set_id(DeviceState *dev, char *id, Error **errp) According to recommendations in error.h, worth adding also return value (for example true=success false=failure), so [..] > { > if (id) { > dev->id = id; > } Unrelated but.. What's the strange logic? Is it intended that with passed id=NULL we don't update dev->id variable but try to do following logic with old dev->id? > > if (dev->id) { > - object_property_add_child(qdev_get_peripheral(), dev->id, > - OBJECT(dev)); > + object_property_try_add_child(qdev_get_peripheral(), dev->id, > + OBJECT(dev), errp); > } else { > static int anon_count; > gchar *name = g_strdup_printf("device[%d]", anon_count++); > - object_property_add_child(qdev_get_peripheral_anon(), name, > - OBJECT(dev)); > + object_property_try_add_child(qdev_get_peripheral_anon(), name, > + OBJECT(dev), errp); > g_free(name); > } > } > > DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) > { > + ERRP_GUARD(); > DeviceClass *dc; > const char *driver, *path; > DeviceState *dev = NULL; > @@ -691,7 +692,10 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) > } > } > > - qdev_set_id(dev, g_strdup(qemu_opts_id(opts))); > + qdev_set_id(dev, g_strdup(qemu_opts_id(opts)), errp); > + if (*errp) { > + goto err_del_dev; > + } [..] here we'll have if (!qdev_set_id(...)) { goto err_del_dev; } and no need for ERRP_GUARD. > > /* set properties */ > if (qemu_opt_foreach(opts, set_property, dev, errp)) { >
Hi Kevin, I proposed a very similar patch in our rfc series because we needed some of the cleaning you do here. https://lists.gnu.org/archive/html/qemu-devel/2021-09/msg05679.html I've added a bit of doc for the function, feel free to take it if you want. On 9/24/21 16:09, Vladimir Sementsov-Ogievskiy wrote: > 24.09.2021 12:04, Kevin Wolf wrote: >> object_property_add_child() fails (with &error_abort) if an object with >> the same name already exists. As long as QemuOpts is in use for -device >> and device_add, it catches duplicate IDs before qdev_set_id() is even >> called. However, for enabling non-QemuOpts code paths, we need to make >> sure that the condition doesn't cause a crash, but fails gracefully. >> >> Signed-off-by: Kevin Wolf <kwolf@redhat.com> >> --- >> include/monitor/qdev.h | 2 +- >> hw/xen/xen-legacy-backend.c | 3 ++- >> softmmu/qdev-monitor.c | 16 ++++++++++------ >> 3 files changed, 13 insertions(+), 8 deletions(-) >> >> diff --git a/include/monitor/qdev.h b/include/monitor/qdev.h >> index 389287eb44..7961308c75 100644 >> --- a/include/monitor/qdev.h >> +++ b/include/monitor/qdev.h >> @@ -9,6 +9,6 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, >> Error **errp); >> int qdev_device_help(QemuOpts *opts); >> DeviceState *qdev_device_add(QemuOpts *opts, Error **errp); >> -void qdev_set_id(DeviceState *dev, char *id); >> +void qdev_set_id(DeviceState *dev, char *id, Error **errp); >> #endif >> diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c >> index dd8ae1452d..17aca85ddc 100644 >> --- a/hw/xen/xen-legacy-backend.c >> +++ b/hw/xen/xen-legacy-backend.c >> @@ -276,7 +276,8 @@ static struct XenLegacyDevice >> *xen_be_get_xendev(const char *type, int dom, >> xendev = g_malloc0(ops->size); >> object_initialize(&xendev->qdev, ops->size, TYPE_XENBACKEND); >> OBJECT(xendev)->free = g_free; >> - qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, >> dev)); >> + qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev), >> + &error_abort); >> qdev_realize(DEVICE(xendev), xen_sysbus, &error_fatal); >> object_unref(OBJECT(xendev)); >> diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c >> index 1207e57a46..c2af906df0 100644 >> --- a/softmmu/qdev-monitor.c >> +++ b/softmmu/qdev-monitor.c >> @@ -593,26 +593,27 @@ static BusState *qbus_find(const char *path, >> Error **errp) >> } >> /* Takes ownership of @id, will be freed when deleting the device */ >> -void qdev_set_id(DeviceState *dev, char *id) >> +void qdev_set_id(DeviceState *dev, char *id, Error **errp) > > According to recommendations in error.h, worth adding also return value > (for example true=success false=failure), so [..] > >> { >> if (id) { >> dev->id = id; >> } > > Unrelated but.. What's the strange logic? > > Is it intended that with passed id=NULL we don't update dev->id variable > but try to do following logic with old dev->id? dev->id is expected to be NULL. The object is created just before calling this function so it is always the case. We could probably assert this. > >> if (dev->id) { >> - object_property_add_child(qdev_get_peripheral(), dev->id, >> - OBJECT(dev)); >> + object_property_try_add_child(qdev_get_peripheral(), dev->id, >> + OBJECT(dev), errp); >> } else { >> static int anon_count; >> gchar *name = g_strdup_printf("device[%d]", anon_count++); >> - object_property_add_child(qdev_get_peripheral_anon(), name, >> - OBJECT(dev)); >> + object_property_try_add_child(qdev_get_peripheral_anon(), name, >> + OBJECT(dev), errp); >> g_free(name); >> } >> } >> DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) >> { >> + ERRP_GUARD(); >> DeviceClass *dc; >> const char *driver, *path; >> DeviceState *dev = NULL; >> @@ -691,7 +692,10 @@ DeviceState *qdev_device_add(QemuOpts *opts, >> Error **errp) >> } >> } >> - qdev_set_id(dev, g_strdup(qemu_opts_id(opts))); >> + qdev_set_id(dev, g_strdup(qemu_opts_id(opts)), errp); >> + if (*errp) { >> + goto err_del_dev; >> + } > > [..] here we'll have > > if (!qdev_set_id(...)) { > goto err_del_dev; > } > > and no need for ERRP_GUARD. > >> /* set properties */ >> if (qemu_opt_foreach(opts, set_property, dev, errp)) { >> > >
Am 27.09.2021 um 12:33 hat Damien Hedde geschrieben: > Hi Kevin, > > I proposed a very similar patch in our rfc series because we needed some of > the cleaning you do here. > https://lists.gnu.org/archive/html/qemu-devel/2021-09/msg05679.html > I've added a bit of doc for the function, feel free to take it if you want. Thanks, I'm replacing my patch with yours for v2. Kevin
diff --git a/include/monitor/qdev.h b/include/monitor/qdev.h index 389287eb44..7961308c75 100644 --- a/include/monitor/qdev.h +++ b/include/monitor/qdev.h @@ -9,6 +9,6 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp); int qdev_device_help(QemuOpts *opts); DeviceState *qdev_device_add(QemuOpts *opts, Error **errp); -void qdev_set_id(DeviceState *dev, char *id); +void qdev_set_id(DeviceState *dev, char *id, Error **errp); #endif diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c index dd8ae1452d..17aca85ddc 100644 --- a/hw/xen/xen-legacy-backend.c +++ b/hw/xen/xen-legacy-backend.c @@ -276,7 +276,8 @@ static struct XenLegacyDevice *xen_be_get_xendev(const char *type, int dom, xendev = g_malloc0(ops->size); object_initialize(&xendev->qdev, ops->size, TYPE_XENBACKEND); OBJECT(xendev)->free = g_free; - qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev)); + qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev), + &error_abort); qdev_realize(DEVICE(xendev), xen_sysbus, &error_fatal); object_unref(OBJECT(xendev)); diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c index 1207e57a46..c2af906df0 100644 --- a/softmmu/qdev-monitor.c +++ b/softmmu/qdev-monitor.c @@ -593,26 +593,27 @@ static BusState *qbus_find(const char *path, Error **errp) } /* Takes ownership of @id, will be freed when deleting the device */ -void qdev_set_id(DeviceState *dev, char *id) +void qdev_set_id(DeviceState *dev, char *id, Error **errp) { if (id) { dev->id = id; } if (dev->id) { - object_property_add_child(qdev_get_peripheral(), dev->id, - OBJECT(dev)); + object_property_try_add_child(qdev_get_peripheral(), dev->id, + OBJECT(dev), errp); } else { static int anon_count; gchar *name = g_strdup_printf("device[%d]", anon_count++); - object_property_add_child(qdev_get_peripheral_anon(), name, - OBJECT(dev)); + object_property_try_add_child(qdev_get_peripheral_anon(), name, + OBJECT(dev), errp); g_free(name); } } DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) { + ERRP_GUARD(); DeviceClass *dc; const char *driver, *path; DeviceState *dev = NULL; @@ -691,7 +692,10 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) } } - qdev_set_id(dev, g_strdup(qemu_opts_id(opts))); + qdev_set_id(dev, g_strdup(qemu_opts_id(opts)), errp); + if (*errp) { + goto err_del_dev; + } /* set properties */ if (qemu_opt_foreach(opts, set_property, dev, errp)) {
object_property_add_child() fails (with &error_abort) if an object with the same name already exists. As long as QemuOpts is in use for -device and device_add, it catches duplicate IDs before qdev_set_id() is even called. However, for enabling non-QemuOpts code paths, we need to make sure that the condition doesn't cause a crash, but fails gracefully. Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- include/monitor/qdev.h | 2 +- hw/xen/xen-legacy-backend.c | 3 ++- softmmu/qdev-monitor.c | 16 ++++++++++------ 3 files changed, 13 insertions(+), 8 deletions(-)