[PATCH] qemu_extdevice: Add a comment into qemuExtDevicesSetupCgroup()

[Laine Stump]

On 2/15/23 10:22 AM, Michal Privoznik wrote:
> The way setting up CGroups for external helpers work, is:
> qemuExtDevicesHasDevice() is called first to determine whether
> there is a helper process running, the CGroup controller is
> created and then qemuExtDevicesSetupCgroup() is called to place
> helpers into the CGroup. But when one reads just
> qemuExtDevicesSetupCgroup() it's easy to miss this hidden logic.
> Therefore, add a warning at the beginning of the function.
> 
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>

Reviewed-by: Laine Stump <laine at redhat.com>

Thanks for indulging me!

> ---
>   src/qemu/qemu_extdevice.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/src/qemu/qemu_extdevice.c b/src/qemu/qemu_extdevice.c
> index 47e97f3565..1c397972e4 100644
> --- a/src/qemu/qemu_extdevice.c
> +++ b/src/qemu/qemu_extdevice.c
> @@ -331,6 +331,9 @@ qemuExtDevicesSetupCgroup(virQEMUDriver *driver,
>       virDomainDef *def = vm->def;
>       size_t i;
>   
> +    /* Don't forget to adjust qemuExtDevicesHasDevice() accordingly.
> +     * Otherwise, this function might not be called at all. */
> +
>       if (qemuDBusSetupCgroup(driver, vm, cgroup) < 0)
>           return -1;
>