Re: [RFC PATCH] os-posix: fix regression for install-less datadir location

[Paolo Bonzini <pbonzini@redhat.com>]

On 16/07/20 16:11, Marc-André Lureau wrote:
> os_find_datadir() used to check the ../share/qemu location (regardless
> of CONFIG_QEMU_DATADIR). It turns out that people rely on that location
> for running qemu in an arbitrary "install-less/portable" fashion. Change
> the logic to return that directory as a last resort.
> 
> (this is an alternative to the patch "[PATCH 1/1] os_find_datadir: search
> as in version 4.2" from Joe Slater)
> 
> Fixes: 6dd2dacedd83d12328 ("os-posix: simplify os_find_datadir")
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

For 5.2 I plan to support fully relocatable installs, so I think this
will not be needed.

The idea is to write a function like

char *get_relocatable_path(const char *dir);

That takes CONFIG_QEMU_*DIR as the argument, turns it into a path
relative to bindir, and tacks it to the end of qemu_get_exec_dir().

So for example all references to CONFIG_QEMU_DATADIR would invoke
get_relocatable_path(CONFIG_QEMU_DATADIR), which would return something
like "/usr/bin/../share/qemu".

Paolo