Re: [Qemu-devel] [PATCH v4] hw/qdev-properties.c: Improve diagnostic for setting property after realize

[Igor Mitsyanko]

On Mar 25, 2013 5:40 PM, "Peter Maydell" <address@hidden> wrote:
>
> Now we have error_setg() we can improve the error message emitted if
> you attempt to set a property of a device after the device is realized
> (the previous message was "permission denied" which was not very
> informative).
>
> Signed-off-by: Peter Maydell <address@hidden>
> ---
> Another attempt at updating this patch (v3 October, v2 July).
> Changes v3->v4:
>  * rebased; some functions have moved file, so the 'set the error'
>    function can't be file-local. Renamed it to something more suitable
>    for a public function and added a doc comment.
>  * added set_taddr to the set of errors changed (and also checked we
>    now have the complete set)
>
> Not changed: Igor suggested using "after it was initialized" rather
> than "after it was realized"; I think the original text is better,
> because (a) we're moving towards having all devices implement realize
> rather than init and (b) it's mostly an error message for QEMU developers
> rather than end-users, so the technical terminology is not inappropriate.
>
>  hw/qdev-addr.c              |    2 +-
>  hw/qdev-properties-system.c |    4 ++--
>  hw/qdev-properties.c        |   40 +++++++++++++++++++++++++++-------------
>  hw/qdev-properties.h        |   12 ++++++++++++
>  hw/qdev.c                   |    2 +-
>  5 files changed, 43 insertions(+), 17 deletions(-)
>

Reviewed-by: Igor Mitsyanko <address@hidden>

> diff --git a/hw/qdev-addr.c b/hw/qdev-addr.c
> index 2398b4a..80a38bb 100644
> --- a/hw/qdev-addr.c
> +++ b/hw/qdev-addr.c
> @@ -42,7 +42,7 @@ static void set_taddr(Object *obj, Visitor *v, void *opaque,
>      int64_t value;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> diff --git a/hw/qdev-properties-system.c b/hw/qdev-properties-system.c
> index 8795144..28813d3 100644
> --- a/hw/qdev-properties-system.c
> +++ b/hw/qdev-properties-system.c
> @@ -43,7 +43,7 @@ static void set_pointer(Object *obj, Visitor *v, Property *prop,
>      int ret;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -287,7 +287,7 @@ static void set_vlan(Object *obj, Visitor *v, void *opaque,
>      NetClientState *hubport;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> diff --git a/hw/qdev-properties.c b/hw/qdev-properties.c
> index 247ca6c..168c466 100644
> --- a/hw/qdev-properties.c
> +++ b/hw/qdev-properties.c
> @@ -7,6 +7,20 @@
>  #include "qapi/visitor.h"
>  #include "char/char.h"
>
> +void qdev_prop_set_after_realize(DeviceState *dev, const char *name,
> +                                  Error **errp)
> +{
> +    if (dev->id) {
> +        error_setg(errp, "Attempt to set property '%s' on device '%s' "
> +                   "(type '%s') after it was realized", name, dev->id,
> +                   object_get_typename(OBJECT(dev)));
> +    } else {
> +        error_setg(errp, "Attempt to set property '%s' on anonymous device "
> +                   "(type '%s') after it was realized", name,
> +                   object_get_typename(OBJECT(dev)));
> +    }
> +}
> +
>  void *qdev_get_prop_ptr(DeviceState *dev, Property *prop)
>  {
>      void *ptr = dev;
> @@ -33,7 +47,7 @@ static void set_enum(Object *obj, Visitor *v, void *opaque,
>      int *ptr = qdev_get_prop_ptr(dev, prop);
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -86,7 +100,7 @@ static void set_bit(Object *obj, Visitor *v, void *opaque,
>      bool value;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -126,7 +140,7 @@ static void set_uint8(Object *obj, Visitor *v, void *opaque,
>      uint8_t *ptr = qdev_get_prop_ptr(dev, prop);
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -193,7 +207,7 @@ static void set_uint16(Object *obj, Visitor *v, void *opaque,
>      uint16_t *ptr = qdev_get_prop_ptr(dev, prop);
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -226,7 +240,7 @@ static void set_uint32(Object *obj, Visitor *v, void *opaque,
>      uint32_t *ptr = qdev_get_prop_ptr(dev, prop);
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -251,7 +265,7 @@ static void set_int32(Object *obj, Visitor *v, void *opaque,
>      int32_t *ptr = qdev_get_prop_ptr(dev, prop);
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -324,7 +338,7 @@ static void set_uint64(Object *obj, Visitor *v, void *opaque,
>      uint64_t *ptr = qdev_get_prop_ptr(dev, prop);
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -414,7 +428,7 @@ static void set_string(Object *obj, Visitor *v, void *opaque,
>      char *str;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -478,7 +492,7 @@ static void set_mac(Object *obj, Visitor *v, void *opaque,
>      char *str, *p;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -570,7 +584,7 @@ static void set_pci_devfn(Object *obj, Visitor *v, void *opaque,
>      char *str;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -641,7 +655,7 @@ static void set_blocksize(Object *obj, Visitor *v, void *opaque,
>      const int64_t max = 32768;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -709,7 +723,7 @@ static void set_pci_host_devaddr(Object *obj, Visitor *v, void *opaque,
>      unsigned int slot = 0, func = 0;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> @@ -824,7 +838,7 @@ static void set_prop_arraylen(Object *obj, Visitor *v, void *opaque,
>      int i;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>      if (*alenptr) {
> diff --git a/hw/qdev-properties.h b/hw/qdev-properties.h
> index c9bb246..a379339 100644
> --- a/hw/qdev-properties.h
> +++ b/hw/qdev-properties.h
> @@ -167,4 +167,16 @@ void error_set_from_qdev_prop_error(Error **errp, int ret, DeviceState *dev,
>   */
>  void qdev_property_add_static(DeviceState *dev, Property *prop, Error **errp);
>
> +/**
> + * @qdev_prop_set_after_realize:
> + * @dev: device
> + * @name: name of property
> + * @errp: indirect pointer to Error to be set
> + * Set the Error object to report that an attempt was made to set a property
> + * on a device after it has already been realized. This is a utility function
> + * which allows property-setter functions to easily report the error in
> + * a friendly format identifying both the device and the property.
> + */
> +void qdev_prop_set_after_realize(DeviceState *dev, const char *name,
> +                                 Error **errp);
>  #endif
> diff --git a/hw/qdev.c b/hw/qdev.c
> index 909c405..6b1947e 100644
> --- a/hw/qdev.c
> +++ b/hw/qdev.c
> @@ -562,7 +562,7 @@ static void qdev_set_legacy_property(Object *obj, Visitor *v, void *opaque,
>      int ret;
>
>      if (dev->realized) {
> -        error_set(errp, QERR_PERMISSION_DENIED);
> +        qdev_prop_set_after_realize(dev, name, errp);
>          return;
>      }
>
> --
> 1.7.9.5
>