Re: [Qemu-devel] [PATCH] vl.c: make default main_loop_wait() timeout independed of slirp

[Eduardo Habkost <ehabkost@redhat.com>]

On Mon, Jun 04, 2018 at 10:14:38PM +0200, Igor Mammedov wrote:
> Since commit (047f7038f58 cli: add --preconfig option) QEMU is
> stuck with indefinite timeout in os_host_main_loop_wait()
> at RUN_STATE_PRECONFIG even if --preconfig option wasn't used
> when it's started with -nodefaults CLI option like this:
> 
>   ./s390x-softmmu/qemu-system-s390x -nodefaults
> 
> It's caused by the fact that slirp_pollfds_fill() bails out early
> and slirp_update_timeout() won't be called to update timeout
> to a reasonable value (1 sec) so timeout would be left with
> infinite value (0xFFFFFFFF).
> 
> Default infinite timeout though doen't make sense and reducing
> it to 1 second as in slirp_update_timeout() won't affect host.

I don't get this part.  Why default infinite timeout doesn't make
sense?  Why would a 1 second timeout make sense?


> Fix issue by simplifying default timeout to the same 1sec as it
> is in slirp_update_timeout() and cleanup the later. It makes
> default timeout the same regardless of slirp_pollfds_fill()
> exited early or not (i.e. -nodefaults won't have any effect on
> main_loop_wait() anymore, which would provide more consistent
> behavior between both variants of startup).
> 
> Reported-by: Lukáš Doktor <ldoktor@redhat.com>
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
> PS:
> it doesn't fix issue reported by Max where
>   "echo foo | $QEMU"
> is also broken due to commit 047f7038f58, but there is antoher fix
> on the list to fix that (either Michal's or Daniel's).
[...]

-- 
Eduardo