From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 270CE26AA8F for ; Tue, 18 Feb 2025 14:37:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739889432; cv=none; b=qwV2PzXam5W3+D3nJgYaSyUVCTLrUMDvXKJdA2E7lrbHrNCS8r53bqdn/dtbEKla/NVS3vlhS4YEaQAEmfigluyzkap0ugWajcZdgEK4yzKJlbUE90fvlUEsp4ukw7PEK8stNLVShftohZJVDanzPS0gtVF+0/k+80zT4BST690= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739889432; c=relaxed/simple; bh=LmtrYjD6Th35wCymIT2wd4L+fI0DTneob1fX71ep0qM=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=HkG2SZD58nt09dVVWGjW5ZKajWLeUcMTkMNRTG35bIRhoFyDrWrZs0XhUQE1R5OAKjVbnxHNjl1z0Nb2RSv0cO5f1gQWMOEswdJ3j4EDSVUVptGGWYAuQA9Hwyv6ByHM1EOeWnQaWFRASTGFKxaFN4kPFpR/BnOQSZCAYAHI2kc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A/2xNzw3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="A/2xNzw3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B6DDC4CEE2; Tue, 18 Feb 2025 14:37:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739889431; bh=LmtrYjD6Th35wCymIT2wd4L+fI0DTneob1fX71ep0qM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=A/2xNzw3iJTljWHHQ6WIoyMWy97XBn1jBwmnEpQRly5l94h4rLcwMeTGOYjMRO9Vv z9Q6WImFZiPpNZnNETesgQzLJq342m4ifknXxyh5T8K3FE58ZKhc2crF80kd/76q/P PjTv8XHFn2vGHRsGoiwzhMpvgZgXCIk3vW/Qg9gLkH9C/rH/HB3eWNSTnMXyD+P4sz GXkoeQT8hJjtSF9FNv63gcwLh5EA5bA2cJMRG3d/DejcCoj5sLiNLvNuLpQdcGVuAS hjpQtvqbIGd3Mreku4mwe7aVGkMDmfJcX5rMZpfU+iBrbPZdkrlyKp4RiTrsixeDc5 8brsvH0pL2jmw== Date: Tue, 18 Feb 2025 06:37:10 -0800 From: Jakub Kicinski To: Toke =?UTF-8?B?SMO4aWxhbmQtSsO4cmdlbnNlbg==?= Cc: "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , netdev@vger.kernel.org Subject: Re: [PATCH net-next] rtnetlink: Allow setting IFLA_PERM_ADDRESS at device creation time Message-ID: <20250218063710.7e1ba2ab@kernel.org> In-Reply-To: <874j0ro1pd.fsf@toke.dk> References: <20250213-virt-dev-permaddr-v1-1-9a616b3de44b@redhat.com> <20250213074039.23200080@kernel.org> <87zfipom9q.fsf@toke.dk> <20250217095150.12cdec05@kernel.org> <874j0ro1pd.fsf@toke.dk> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, 18 Feb 2025 13:51:42 +0100 Toke H=C3=B8iland-J=C3=B8rgensen wrote: > >> Hmm, and you don't see any value in being able to specify a permanent > >> identifier for virtual devices? That bit was not just motivated > >> reasoning on my part... :) =20 > > > > I can't think of any :( Specifying an address is already possible. =20 >=20 > Right, but the address can be changed later. Setting the perm_addr makes > it possible for a management daemon to set a unique identifier at device > creation time which is guaranteed to persist through any renames and > address changes that other utilities may perform. That seems like a > useful robustness feature that comes at a relatively low cost (the patch > is fairly small and uncomplicated)? >=20 > > Permanent address is a property of the hardware platform. > > Virtual devices OTOH are primarily used by containers,=20 > > which are ephemeral by design. At least that's my mental model. =20 >=20 > Sure, any device feature that comes from hardware is only going to fit > virtual devices by analogy. But I don't think the analogy here is super > far fetched (cf the above)? :) I'm not sure how to answer this. It all sounds really speculative and disconnected with how I see virtual devices being used.