From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58459) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WSNZu-0003JN-Ul for qemu-devel@nongnu.org; Tue, 25 Mar 2014 05:23:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WSNZo-00012X-Sc for qemu-devel@nongnu.org; Tue, 25 Mar 2014 05:23:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56752) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WSNZo-00012Q-L8 for qemu-devel@nongnu.org; Tue, 25 Mar 2014 05:23:20 -0400 Date: Tue, 25 Mar 2014 09:23:13 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20140325092313.GB2459@work-vm> References: <1395671853-2685-1-git-send-email-mst@redhat.com> <1395671853-2685-4-git-send-email-mst@redhat.com> <20140324171115.GI3829@work-vm> <20140324215027.GA15488@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140324215027.GA15488@redhat.com> Subject: Re: [Qemu-devel] [RFC v2 3/5] vmstate: add VMS_MUST_EXIST List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Peter Maydell , qemu-devel@nongnu.org * Michael S. Tsirkin (mst@redhat.com) wrote: > On Mon, Mar 24, 2014 at 05:11:16PM +0000, Dr. David Alan Gilbert wrote: > > I think your intent here is just to misuse the field_exist function pointer > > as a call for a different reason as a hook for a validator; is it really worth > > misusing it like that or is something more explicit worth it? > > Perhaps something passed an Error** so it could pass back what was wrong? > > > Well adding a required field seems valuable by itself, does it not? Maybe; however most fields are always-present, unless they have a test function or minimum version, so it's a little weird to add a 'required' when that's the default. > And there's no way to pass in Error** since none of the callers > has Error**: all of migration still uses stderr to pass > errors. > > So we could add an API but it doesn't seem too valuable. > > Since all callers will use this through a wrapper like VMSTATE_TEST, > it will be easy to change our mind later. Yep, that's fine - was just an idea. Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK