Steve Sistare <steven.sist...@oracle.com> writes:
> Provide the -pause command-line parameter and the QEMU_PAUSE environment
> variable to briefly pause QEMU in main and allow a developer to attach gdb.
> Useful when the developer does not invoke QEMU directly, such as when using
> libvirt.
How does this differ from -S?
>
> Usage:
> qemu -pause <seconds>
> or
> export QEMU_PAUSE=<seconds>
>
> Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
> ---
> qemu-options.hx | 9 +++++++++
> softmmu/vl.c | 15 ++++++++++++++-
> 2 files changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 708583b..8505cf2 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -3668,6 +3668,15 @@ SRST
> option is experimental.
> ERST
>
> +DEF("pause", HAS_ARG, QEMU_OPTION_pause, \
> + "-pause secs Pause for secs seconds on entry to main.\n",
> QEMU_ARCH_ALL)
> +
> +SRST
> +``--pause secs``
> + Pause for a number of seconds on entry to main. Useful for attaching
> + a debugger after QEMU has been launched by some other entity.
> +ERST
> +
It seems like having an option to race with the debugger is just asking
for trouble.
> DEF("S", 0, QEMU_OPTION_S, \
> "-S freeze CPU at startup (use 'c' to start execution)\n",
> QEMU_ARCH_ALL)
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index 8478778..951994f 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -2844,7 +2844,7 @@ static void create_default_memdev(MachineState *ms,
> const char *path)
>
> void qemu_init(int argc, char **argv, char **envp)
> {
> - int i;
> + int i, seconds;
> int snapshot, linux_boot;
> const char *initrd_filename;
> const char *kernel_filename, *kernel_cmdline;
> @@ -2882,6 +2882,13 @@ void qemu_init(int argc, char **argv, char **envp)
> QemuPluginList plugin_list = QTAILQ_HEAD_INITIALIZER(plugin_list);
> int mem_prealloc = 0; /* force preallocation of physical target memory */
>
> + if (getenv("QEMU_PAUSE")) {
> + seconds = atoi(getenv("QEMU_PAUSE"));
> + printf("Pausing %d seconds for debugger. QEMU PID is %d\n",
> + seconds, getpid());
> + sleep(seconds);
> + }
> +
> os_set_line_buffering();
>
> error_init(argv[0]);
> @@ -3204,6 +3211,12 @@ void qemu_init(int argc, char **argv, char **envp)
> case QEMU_OPTION_gdb:
> add_device_config(DEV_GDB, optarg);
> break;
> + case QEMU_OPTION_pause:
> + seconds = atoi(optarg);
> + printf("Pausing %d seconds for debugger. QEMU PID is %d\n",
> + seconds, getpid());
> + sleep(seconds);
> + break;
> case QEMU_OPTION_L:
> if (is_help_option(optarg)) {
> list_data_dirs = true;
--
Alex Bennée
