Re: [PATCH V1 12/32] vl: pause option

[Eric Blake]

On 7/30/20 10:14 AM, Steve Sistare wrote:
> 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 would you set this option with libvirt?

It feels like you are trying to reinvent something that is already 
well-documented:

https://www.berrange.com/posts/2011/10/12/debugging-early-startup-of-kvm-with-gdb-when-launched-by-libvirtd/

> Usage:
>    qemu -pause <seconds>
>    or
>    export QEMU_PAUSE=<seconds>
>
> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
> ---
>   qemu-options.hx |  9 +++++++++
>   softmmu/vl.c    | 15 ++++++++++++++-
>   2 files changed, 23 insertions(+), 1 deletion(-)

> @@ -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);

atoi() cannot detect overflow.  You should never use it in robust 
parsing of untrusted input.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org