From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42194) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VJm03-0000eh-UD for qemu-devel@nongnu.org; Wed, 11 Sep 2013 11:06:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VJlzt-0006GC-Rd for qemu-devel@nongnu.org; Wed, 11 Sep 2013 11:06:35 -0400 Received: from mail-pb0-x22f.google.com ([2607:f8b0:400e:c01::22f]:49815) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VJlzt-0006G6-Ji for qemu-devel@nongnu.org; Wed, 11 Sep 2013 11:06:25 -0400 Received: by mail-pb0-f47.google.com with SMTP id rr4so9137142pbb.20 for ; Wed, 11 Sep 2013 08:06:24 -0700 (PDT) Sender: Richard Henderson Message-ID: <523086EC.1020103@twiddle.net> Date: Wed, 11 Sep 2013 08:06:20 -0700 From: Richard Henderson MIME-Version: 1.0 References: <1378877909-28518-1-git-send-email-famz@redhat.com> <1378877909-28518-5-git-send-email-famz@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH v5 4/6] module: implement module loading function List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Bligh Cc: peter.maydell@linaro.org, Fam Zheng , mjt@tls.msk.ru, qemu-devel@nongnu.org, stefanha@redhat.com, pbonzini@redhat.com, vilanova@ac.upc.edu On 09/11/2013 07:10 AM, Alex Bligh wrote: > > > --On 11 September 2013 13:38:27 +0800 Fam Zheng wrote: > >> + switch (type) { >> + case MODULE_LOAD_BLOCK: >> + path = CONFIG_PREFIX "/qemu/block/"; >> + break; >> + case MODULE_LOAD_UI: >> + path = CONFIG_PREFIX "/qemu/ui/"; >> + break; >> + case MODULE_LOAD_NET: >> + path = CONFIG_PREFIX "/qemu/net/"; >> + break; >> + default: >> + return; >> + } >> + > > I appreciate I am coming in late into this discussion, and am only scanning > the code quickly, so apologies if I have the wrong end of the stick. > > This APPEARS to load modules from > a) a fixed path determined at compile time > b) a path which is not dependent on qemu version > > This would make it hard to have 2 versions of qemu installed on a > system at once, or even develop one version of qemu with another > version installed. I suspect this will be hard not only for developers, > but also for distributions, particularly if the idea is to keep vms > running during upgrades. Consider the case where packages A and B > both depend on qemu module package C, then you wish to upgrade to > A', B' and C'. At some point you are likely to want both C and C' > installed. Is the idea here that QEMU is always built with CONFIG_PREFIX > having versioning inside it (in a distro environment)? > > Can I suggest that at the very least, it should be possible to specify > an alternate path to the module directory via the CLI? > If we want dependencies between modules, we may well need to get the dynamic linker involved with the search directory. This would rule out any command-line, or monitor-line altering of the path. But it does suggest the default being DT_RUNPATH, overridable "near" the command-line via LD_RUN_PATH. I also wonder about the utility of the subdirectories above, as opposed to filename prefixes. r~