Re: [Qemu-devel] [PATCH 4/4] Warning messages on net devices hotplug

[Paolo Bonzini <pbonzini@redhat.com>]

Il 17/10/2012 15:15, Eduardo Otubo ha scritto:
> With the inclusion of the new "double whitelist" seccomp filter, Qemu
> won't be able to execve() in runtime, thus, no hotplug net devices
> allowed.
> 
> Signed-off-by: Eduardo Otubo <otubo@linux.vnet.ibm.com>

Please check this in net_init_tap instead.  When using libvirt, hotplug
is done with a completely different mechanism that involves
file-descriptor passing and does not require executing a helper.

Paolo

> ---
>  hmp.c |  6 ++++++
>  net.c | 13 +++++++++++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/hmp.c b/hmp.c
> index 70bdec2..f258338 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -1091,6 +1091,12 @@ void hmp_netdev_add(Monitor *mon, const QDict *qdict)
>      Error *err = NULL;
>      QemuOpts *opts;
>  
> +#ifdef CONFIG_SECCOMP
> +    error_set(&err, ERROR_CLASS_GENERIC_ERROR,
> +            "Cannot hotplug TAP device when -sandbox is in effect");
> +    goto out;
> +#endif
> +
>      opts = qemu_opts_from_qdict(qemu_find_opts("netdev"), qdict, &err);
>      if (error_is_set(&err)) {
>          goto out;
> diff --git a/net.c b/net.c
> index ae4bc0d..a652ee9 100644
> --- a/net.c
> +++ b/net.c
> @@ -752,6 +752,12 @@ void net_host_device_add(Monitor *mon, const QDict *qdict)
>      Error *local_err = NULL;
>      QemuOpts *opts;
>  
> +#ifdef CONFIG_SECCOMP
> +    error_set(&local_err, ERROR_CLASS_GENERIC_ERROR,
> +            "Cannot hotplug TAP device when -sandbox is in effect");
> +    goto out;
> +#endif
> +
>      if (!net_host_check_device(device)) {
>          monitor_printf(mon, "invalid host network device %s\n", device);
>          return;
> @@ -765,6 +771,7 @@ void net_host_device_add(Monitor *mon, const QDict *qdict)
>      qemu_opt_set(opts, "type", device);
>  
>      net_client_init(opts, 0, &local_err);
> +out:
>      if (error_is_set(&local_err)) {
>          qerror_report_err(local_err);
>          error_free(local_err);
> @@ -800,6 +807,12 @@ int qmp_netdev_add(Monitor *mon, const QDict *qdict, QObject **ret)
>      QemuOptsList *opts_list;
>      QemuOpts *opts;
>  
> +#ifdef CONFIG_SECCOMP
> +    error_set(&local_err, ERROR_CLASS_GENERIC_ERROR,
> +            "Cannot hotplug TAP device when -sandbox is in effect");
> +    goto exit_err;
> +#endif
> +
>      opts_list = qemu_find_opts_err("netdev", &local_err);
>      if (error_is_set(&local_err)) {
>          goto exit_err;
>