Re: [Qemu-devel] [PATCH v9 01/10] net: add a new object netfilter

[Daniel P. Berrange]

On Wed, Sep 02, 2015 at 01:58:58PM +0100, Stefan Hajnoczi wrote:
> On Wed, Sep 02, 2015 at 09:39:11AM +0800, Yang Hongyang wrote:
> > On 09/01/2015 10:36 PM, Stefan Hajnoczi wrote:
> > >On Tue, Sep 01, 2015 at 05:06:14PM +0800, Yang Hongyang wrote:
> > >>diff --git a/qemu-options.hx b/qemu-options.hx
> > >>index 77f5853..f1d42a1 100644
> > >>--- a/qemu-options.hx
> > >>+++ b/qemu-options.hx
> > >>@@ -1991,6 +1991,27 @@ override the default configuration (@option{-net 
> > >>nic -net user}) which
> > >>  is activated if no @option{-net} options are provided.
> > >>  ETEXI
> > >>
> > >>+DEF("netfilter", HAS_ARG, QEMU_OPTION_netfilter,
> > >>+    "-netfilter buffer,id=str,netdev=str[,chain=in|out|all,interval=t]\n"
> > >>+    "                buffer network packets on netdev. if interval 
> > >>provided, will release\n"
> > >>+    "                packets by interval. Interval scale: 
> > >>microsecond\n", QEMU_ARCH_ALL)
> > >
> > >Perhaps the -object option should be used:
> > >
> > >   -object netfilter-buffer,id=str,netdev=str[,chain=in|out|all,interval=t]
> > >
> > >That is how IOThread and memory backends were recently added.
> > >
> > >They are QOM objects (see include/qom/object.h) and eliminate the need
> > >to write boilerplate code that adds new command-line options and
> > >instantiates objects.
> > 
> > I thought -netfilter is more obvious for an object name, -object is kind of
> > abstract name... but I'm not maintainer, if you think it's really need to
> > change to -object, I can do that.
> 
> The advantage of QOM and -object is that it eliminates code for
> command-line options, object instantiation, etc.  They introduce a
> single object model that all types within QEMU can use instead of
> inventing their own.
> 
> Personally I'm not that involved in QAPI or command-line but I thought
> -object was the new preferred way to do things.

Yep, you're right - using QOM would be a better idea as it avoids
all the QemuOpts boilerplate command line handling and being part
of the standard object framework makes introspection easier for
apps too.

Regards,
Daniel
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