On 09/11/2013 07:10 AM, Alex Bligh wrote: > > > --On 11 September 2013 13:38:27 +0800 Fam Zheng <f...@redhat.com> 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~