Re: [Qemu-devel] [PATCH v2 1/2] qdev-properties: add UUID property type

[Marc-André Lureau]

On Mon, Nov 27, 2017 at 2:05 PM, Roman Kagan <address@hidden> wrote:
> UUIDs (GUIDs) are widely used in VMBus-related stuff, so a dedicated
> property type becomes helpful.
>
> The property accepts a string-formatted UUID or a special keyword "auto"
> meaning a randomly generated UUID; the latter is also the default when
> the property is not given a value explicitly.
>
> Signed-off-by: Roman Kagan <address@hidden>

Reviewed-by: Marc-André Lureau <address@hidden>


> ---
> v1 -> v2:
>  - make the property default to autogeneration if not specified
>    explicitly
>
>  include/hw/qdev-properties.h |  9 +++++++
>  hw/core/qdev-properties.c    | 61 
> ++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 70 insertions(+)
>
> diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
> index e2321f1cc1..efb22ba80c 100644
> --- a/include/hw/qdev-properties.h
> +++ b/include/hw/qdev-properties.h
> @@ -30,6 +30,7 @@ extern const PropertyInfo qdev_prop_vlan;
>  extern const PropertyInfo qdev_prop_pci_devfn;
>  extern const PropertyInfo qdev_prop_blocksize;
>  extern const PropertyInfo qdev_prop_pci_host_devaddr;
> +extern const PropertyInfo qdev_prop_uuid;
>  extern const PropertyInfo qdev_prop_arraylen;
>  extern const PropertyInfo qdev_prop_link;
>
> @@ -213,6 +214,14 @@ extern const PropertyInfo qdev_prop_link;
>  #define DEFINE_PROP_MEMORY_REGION(_n, _s, _f)             \
>      DEFINE_PROP(_n, _s, _f, qdev_prop_ptr, MemoryRegion *)
>
> +#define DEFINE_PROP_UUID(_name, _state, _field) {                  \
> +        .name      = (_name),                                      \
> +        .info      = &qdev_prop_uuid,                              \
> +        .offset    = offsetof(_state, _field)                      \
> +            + type_check(QemuUUID, typeof_field(_state, _field)),  \
> +        .set_default = true,                                       \
> +        }
> +
>  #define DEFINE_PROP_END_OF_LIST()               \
>      {}
>
> diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
> index 1dc80fcea2..24c17800e3 100644
> --- a/hw/core/qdev-properties.c
> +++ b/hw/core/qdev-properties.c
> @@ -10,6 +10,7 @@
>  #include "net/hub.h"
>  #include "qapi/visitor.h"
>  #include "chardev/char.h"
> +#include "qemu/uuid.h"
>
>  void qdev_prop_set_after_realize(DeviceState *dev, const char *name,
>                                    Error **errp)
> @@ -883,6 +884,66 @@ const PropertyInfo qdev_prop_pci_host_devaddr = {
>      .set = set_pci_host_devaddr,
>  };
>
> +/* --- UUID --- */
> +
> +static void get_uuid(Object *obj, Visitor *v, const char *name, void *opaque,
> +                     Error **errp)
> +{
> +    DeviceState *dev = DEVICE(obj);
> +    Property *prop = opaque;
> +    QemuUUID *uuid = qdev_get_prop_ptr(dev, prop);
> +    char buffer[UUID_FMT_LEN + 1];
> +    char *p = buffer;
> +
> +    qemu_uuid_unparse(uuid, buffer);
> +
> +    visit_type_str(v, name, &p, errp);
> +}
> +
> +#define UUID_VALUE_AUTO        "auto"
> +
> +static void set_uuid(Object *obj, Visitor *v, const char *name, void *opaque,
> +                    Error **errp)
> +{
> +    DeviceState *dev = DEVICE(obj);
> +    Property *prop = opaque;
> +    QemuUUID *uuid = qdev_get_prop_ptr(dev, prop);
> +    Error *local_err = NULL;
> +    char *str;
> +
> +    if (dev->realized) {
> +        qdev_prop_set_after_realize(dev, name, errp);
> +        return;
> +    }
> +
> +    visit_type_str(v, name, &str, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
> +
> +    if (!strcmp(str, UUID_VALUE_AUTO)) {
> +        qemu_uuid_generate(uuid);
> +    } else if (qemu_uuid_parse(str, uuid) < 0) {
> +        error_set_from_qdev_prop_error(errp, EINVAL, dev, prop, str);
> +    }
> +    g_free(str);
> +}
> +
> +static void set_default_uuid_auto(Object *obj, const Property *prop)
> +{
> +    object_property_set_str(obj, UUID_VALUE_AUTO, prop->name, &error_abort);
> +}
> +
> +const PropertyInfo qdev_prop_uuid = {
> +    .name  = "str",
> +    .description = "UUID (aka GUID) or \"" UUID_VALUE_AUTO
> +        "\" for random value (default)",
> +    .get   = get_uuid,
> +    .set   = set_uuid,
> +    .set_default_value = set_default_uuid_auto,
> +};
> +
>  /* --- support for array properties --- */
>
>  /* Used as an opaque for the object properties we add for each
> --
> 2.14.3
>
>



-- 
Marc-André Lureau