On 1/21/26 3:48 PM, Stefano Garzarella wrote: >> diff --git a/Documentation/admin-guide/kernel-parameters.txt >> b/Documentation/admin-guide/kernel-parameters.txt >> index a8d0afde7f85..b6e3bfe365a1 100644 >> --- a/Documentation/admin-guide/kernel-parameters.txt >> +++ b/Documentation/admin-guide/kernel-parameters.txt >> @@ -8253,6 +8253,20 @@ Kernel parameters >> them quite hard to use for exploits but >> might break your system. >> >> + vsock_init_ns_mode= >> + [KNL,NET] Set the vsock namespace mode for the init >> + (root) network namespace. >> + >> + global [default] The init namespace operates in >> + global mode where CIDs are system-wide and >> + sockets can communicate across global >> + namespaces. >> + >> + local The init namespace operates in local mode >> + where CIDs are private to the namespace and >> + sockets can only communicate within the same >> + namespace. >> + > > My comment on v14 was more to start a discussion :-) sorry to not be > clear. > > I briefly discussed it with Paolo in chat to better understand our > policy between cmdline parameters and module parameters, and it seems > that both are discouraged.
Double checking the git log it looks like __setup() usage is less constrained/restricted than what I thought. > So he asked me if we have a use case for this, and thinking about it, I > don't have one at the moment. Also, if a user decides to set all netns > to local, whether init_net is local or global doesn't really matter, > right? > > So perhaps before adding this, we should have a real use case. > Perhaps more than this feature, I would add a way to change the default > of all netns (including init_net) from global to local. But we can do > that later, since all netns have a way to understand what mode they are > in, so we don't break anything and the user has to explicitly change it, > knowing that they are breaking compatibility with pre-netns support.\ Lacking a clear use-case for vsock_init_ns_mode I tend to think it would be better to postpone its introduction. It should be easier to add it later than vice-versa. If there is a clear/well defined/known use-case, I guess the series can go as-is. /P
