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

[Corey Minyard]

On 11/24/2017 09:36 AM, Roman Kagan wrote:
> UUIDs (GUIDs) are widely used in VMBus-related stuff, so a dedicated
> property type becomes helpful.
>
> Signed-off-by: Roman Kagan <address@hidden>
> ---
>   include/hw/qdev-properties.h |  3 +++
>   hw/core/qdev-properties.c    | 52 ++++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 55 insertions(+)
>
> diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
> index e2321f1cc1..d4da7dd1f1 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;
>   
> @@ -212,6 +213,8 @@ extern const PropertyInfo qdev_prop_link;
>       DEFINE_PROP(_n, _s, _f, qdev_prop_pci_host_devaddr, PCIHostDeviceAddress)
>   #define DEFINE_PROP_MEMORY_REGION(_n, _s, _f)             \
>       DEFINE_PROP(_n, _s, _f, qdev_prop_ptr, MemoryRegion *)
> +#define DEFINE_PROP_UUID(_n, _s, _f) \
> +    DEFINE_PROP(_n, _s, _f, qdev_prop_uuid, QemuUUID)
>   
>   #define DEFINE_PROP_END_OF_LIST()               \
>       {}
> diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
> index 1dc80fcea2..49fea5a40a 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 +884,57 @@ 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);
> +}
> +
> +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, "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);
> +}
> +
> +const PropertyInfo qdev_prop_uuid = {
> +    .name  = "str",
> +    .description = "UUID (aka GUID) or \"auto\" for random value",
> +    .get   = get_uuid,
> +    .set   = set_uuid,

There is a UUID value you can use as a default in  vl.c, named qemu_uuid.
Just in case you want to set a default value here.

-corey

> +};
> +
>   /* --- support for array properties --- */
>   
>   /* Used as an opaque for the object properties we add for each