RE: [PATCH 1/1] os_find_datadir: search as in version 4.2

[Slater, Joseph]

Hi Peter,

Specifically, 5.0 breaks the way yocto runqemu starts qemu-system-*.  The 
installation path which is not known at qemu build time, is 
<arbitrary-prefix>/usr/{bin,share}.  In general, though, I think it's a good 
idea to look in "reasonable" locations relative to the executable, maybe with 
command line options taking precedence.

Joe

-----Original Message-----
From: Peter Maydell <peter.maydell@linaro.org> 
Sent: Tuesday, June 16, 2020 2:20 AM
To: Slater, Joseph <joe.slater@windriver.com>
Cc: QEMU Developers <qemu-devel@nongnu.org>; MacLeod, Randy 
<Randy.MacLeod@windriver.com>; Marc-André Lureau <marcandre.lureau@redhat.com>; 
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH 1/1] os_find_datadir: search as in version 4.2

On Tue, 16 Jun 2020 at 00:00, Joe Slater <joe.slater@windriver.com> wrote:
>
> Always look for ../share/qemu then ../pc-bios when looking for datadir.

Could you provide some more context, please? Why is this change useful; 
presumably we broke some setup in 5.0, but what exactly ?

I'm guessing this might be a regression introduced by commit
6dd2dacedd83d12328 so I'm ccing the relevant people.

> Signed-off-by: Joe Slater <joe.slater@windriver.com>
> ---
>  os-posix.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/os-posix.c b/os-posix.c
> index 3cd52e1e70..f77da94bf6 100644
> --- a/os-posix.c
> +++ b/os-posix.c
> @@ -82,8 +82,9 @@ void os_setup_signal_handling(void)
>
>  /*
>   * Find a likely location for support files using the location of the binary.
> + * Typically, this would be "$bindir/../share/qemu".
>   * When running from the build tree this will be "$bindir/../pc-bios".
> - * Otherwise, this is CONFIG_QEMU_DATADIR.
> + * Otherwise, this is CONFIG_QEMU_DATADIR as constructed by configure.
>   */
>  char *os_find_datadir(void)
>  {
> @@ -93,6 +94,12 @@ char *os_find_datadir(void)
>      exec_dir = qemu_get_exec_dir();
>      g_return_val_if_fail(exec_dir != NULL, NULL);
>
> +    dir = g_build_filename(exec_dir, "..", "share", "qemu", NULL);
> +    if (g_file_test(dir, G_FILE_TEST_IS_DIR)) {
> +        return g_steal_pointer(&dir);
> +    }
> +    g_free(dir);  /* no autofree this time */
> +
>      dir = g_build_filename(exec_dir, "..", "pc-bios", NULL);
>      if (g_file_test(dir, G_FILE_TEST_IS_DIR)) {
>          return g_steal_pointer(&dir);
> --
> 2.17.1