From 95e30b2a131ed1f94ab7a64326243943317aa18a Mon Sep 17 00:00:00 2001 From: Marc-André Lureau Date: Wed, 22 Aug 2018 19:19:42 +0200 Subject: chardev: mark the calls that allow an implicit mux monitor MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This is mostly for readability of the code. Let's make it clear which callers can create an implicit monitor when the chardev is muxed. This will also enforce a safer behaviour, as we don't really support creating monitor anywhere/anytime at the moment. Add an assert() to make sure the programmer explicitely wanted that behaviour. There are documented cases, such as: -serial/-parallel/-virtioconsole and to less extent -debugcon. Less obvious and questionable ones are -gdb, SLIRP -guestfwd and Xen console. Add a FIXME note for those, but keep the support for now. Other qemu_chr_new() callers either have a fixed parameter/filename string or do not need it, such as -qtest: * qtest.c: qtest_init() Afaik, only used by tests/libqtest.c, without mux. I don't think we support it outside of qemu testing: drop support for implicit mux monitor (qemu_chr_new() call: no implicit mux now). * hw/ All with literal @filename argument that doesn't enable mux monitor. * tests/ All with @filename argument that doesn't enable mux monitor. On a related note, the list of monitor creation places: - the chardev creators listed above: all from command line (except perhaps Xen console?) - -gdb & hmp gdbserver will create a "GDB monitor command" chardev that is wired to an HMP monitor. - -mon command line option From this short study, I would like to think that a monitor may only be created in the main thread today, though I remain skeptical :) Signed-off-by: Marc-André Lureau Reviewed-by: Markus Armbruster --- gdbstub.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'gdbstub.c') diff --git a/gdbstub.c b/gdbstub.c index d6ab95006c..c8478de8f5 100644 --- a/gdbstub.c +++ b/gdbstub.c @@ -2038,7 +2038,11 @@ int gdbserver_start(const char *device) sigaction(SIGINT, &act, NULL); } #endif - chr = qemu_chr_new_noreplay("gdb", device); + /* + * FIXME: it's a bit weird to allow using a mux chardev here + * and implicitly setup a monitor. We may want to break this. + */ + chr = qemu_chr_new_noreplay("gdb", device, true); if (!chr) return -1; } -- cgit 1.4.1