Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 23 Feb 2022 19:44:26 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Marek =?UTF-8?B?TWFyY3p5a293c2tpLUfDs3JlY2tp?= 
        <marmarek@invisiblethingslab.com>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Michael Brown <mcb30@ipxe.org>, Wei Liu <wei.liu@kernel.org>,
        Paul Durrant <paul@xen.org>,
        "David S. Miller" <davem@davemloft.net>,
        xen-devel@lists.xenproject.org (moderated list:XEN NETWORK BACKEND
        DRIVER),
        netdev@vger.kernel.org (open list:XEN NETWORK BACKEND DRIVER)
Subject: Re: [PATCH v2 1/2] Revert "xen-netback: remove 'hotplug-status'
 once it has served its purpose"
Message-ID: <20220223194426.6948b28c@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
In-Reply-To: <20220222001817.2264967-1-marmarek@invisiblethingslab.com>
References: <20220222001817.2264967-1-marmarek@invisiblethingslab.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Tue, 22 Feb 2022 01:18:16 +0100 Marek Marczykowski-G=C3=B3recki wrote:
> This reverts commit 1f2565780e9b7218cf92c7630130e82dcc0fe9c2.
>=20
> The 'hotplug-status' node should not be removed as long as the vif
> device remains configured. Otherwise the xen-netback would wait for
> re-running the network script even if it was already called (in case of
> the frontent re-connecting). But also, it _should_ be removed when the
> vif device is destroyed (for example when unbinding the driver) -
> otherwise hotplug script would not configure the device whenever it
> re-appear.
>=20
> Moving removal of the 'hotplug-status' node was a workaround for nothing
> calling network script after xen-netback module is reloaded. But when
> vif interface is re-created (on xen-netback unbind/bind for example),
> the script should be called, regardless of who does that - currently
> this case is not handled by the toolstack, and requires manual
> script call. Keeping hotplug-status=3Dconnected to skip the call is wrong
> and leads to not configured interface.
>=20
> More discussion at
> https://lore.kernel.org/xen-devel/afedd7cb-a291-e773-8b0d-4db9b291fa98@ip=
xe.org/T/#u
>=20
> Cc: stable@vger.kernel.org
> Signed-off-by: Marek Marczykowski-G=C3=B3recki <marmarek@invisiblethingsl=
ab.com>

Wei, Paul, do these look good?