From 2ee3518b53cd82bca10448283bd8fe5a259c27b1 Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Wed, 20 Jun 2018 15:24:19 +0200 Subject: [PATCH] vl.c: do not allow --daemonize in combination with --preconfig CLI option some users when using --daemonize expect that QEMU will parse CLI options, initialize VM and only then complete daemonzation by signalling lead process to exit and start listening on monitor socket. So users treat parent process exit as sync point to connect to QEMU's monitor. That however doesn't work when --preconfig options is used, since it provides monitor before completing daemonization and expects user to issue exit-preconfig command when additional configuration via monitor is finished. We also can't move completing daemonization before preconfig monitor becomes available, since that would imply: * partially loosing ability to configure QEMU instance in --preconfig mode since QEMU might drop privileges, chroot and do other things when daemonization is completed * lead to loss of error messages in case they would happen after daemonization Be proactive now and make options mutually exclusive, so users would get clear error message instead of waiting for lead process exit indefinitely before connecting to monitor. PS: In case someone would come up with usecase where both options should be enabled at the same time we could drop this restriction as far as daemonization point is left where it is now (os_setup_post). Signed-off-by: Igor Mammedov Message-Id: <1529501059-163139-1-git-send-email-imammedo@redhat.com> Signed-off-by: Eduardo Habkost --- vl.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/vl.c b/vl.c index d451f45dc5..a37dfe4684 100644 --- a/vl.c +++ b/vl.c @@ -4134,6 +4134,12 @@ int main(int argc, char **argv, char **envp) } if (is_daemonized()) { + if (!preconfig_exit_requested) { + error_report("'preconfig' and 'daemonize' options are " + "mutually exclusive"); + exit(EXIT_FAILURE); + } + /* According to documentation and historically, -nographic redirects * serial port, parallel port and monitor to stdio, which does not work * with -daemonize. We can redirect these to null instead, but since