Re: [Qemu-devel] [PATCH 4/7] qemu-io: add support for --object command line arg

[Eric Blake <eblake@redhat.com>]

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On 12/22/2015 04:06 AM, Daniel P. Berrange wrote:
> Allow creation of user creatable object types with qemu-io
> via a --object command line arg. This will be used to supply
> passwords and/or encryption keys to the various block driver
> backends via the recently added 'secret' object type.
> 
>  # echo -n letmein > mypasswd.txt
>  # qemu-io --object secret,id=sec0,file=mypasswd.txt \
>       ...other args...

Same comments as on 3/7.

> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  qemu-io.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 87 insertions(+)

> @@ -205,6 +207,9 @@ static void usage(const char *name)
>  "Usage: %s [-h] [-V] [-rsnm] [-f FMT] [-c STRING] ... [file]\n"
>  "QEMU Disk exerciser\n"
>  "\n"
> +"  --object OBJECTDEF   define a object such as 'secret' for\n"

s/a object/an object/

> +"                       providing passwords and/or encryption\n"
> +"                       keys\n"

3 lines feels long; you got away with only 2 lines in 3/7 by using
longer line wrapping, while still fitting in the user's 80 column output:

+"  --object type,id=ID,...   define an object such as 'secret' for
providing\n"
+"                            passwords and/or encryption keys\n"


>  
> +enum {
> +    OPTION_OBJECT = 258,
> +};

256 would work. But 258 doesn't hurt.


> +static int object_create(void *opaque, QemuOpts *opts, Error **errp)
> +{
> +    Error *err = NULL;
> +    char *type = NULL;
> +    char *id = NULL;
> +    void *dummy = NULL;
> +    OptsVisitor *ov;
> +    QDict *pdict;
> +
> +    ov = opts_visitor_new(opts);
> +    pdict = qemu_opts_to_qdict(opts, NULL);
> +
> +    visit_start_struct(opts_get_visitor(ov), &dummy, NULL, NULL, 0, &err);

Same comments as on 3/7.

We now have 5 very similar functions (hmp.c, vl.c, and your three
additions); should this be factored into a common reusable function
rather than open-coding it into each client?

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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