From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [virtio-dev] Re: [Qemu-devel] [PATCH] qemu: Introduce VIRTIO_NET_F_STANDBY feature bit to virtio_net Date: Tue, 26 Jun 2018 04:50:25 +0300 Message-ID: <20180626044650-mutt-send-email-mst@kernel.org> References: <20180622053141-mutt-send-email-mst@kernel.org> <20180623002628-mutt-send-email-mst@kernel.org> <20180623012406-mutt-send-email-mst@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Cc: Alexander Duyck , virtio-dev@lists.oasis-open.org, Jiri Pirko , konrad.wilk@oracle.com, Jakub Kicinski , Netdev , Cornelia Huck , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, Siwei Liu , Venu Busireddy , boris.ostrovsky@oracle.com, aaron.f.brown@intel.com, Joao Martins To: "Samudrala, Sridhar" Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org On Mon, Jun 25, 2018 at 10:54:09AM -0700, Samudrala, Sridhar wrote: > > > > > Might not neccessarily be something wrong, but it's very limited = to > > > > > prohibit the MAC of VF from changing when enslaved by failover. > > > > You mean guest changing MAC? I'm not sure why we prohibit that. > > > I think Sridhar and Jiri might be better person to answer it. My > > > impression was that sync'ing the MAC address change between all 3 > > > devices is challenging, as the failover driver uses MAC address to > > > match net_device internally. > = > Yes. The MAC address is assigned by the hypervisor and it needs to manage= the movement > of the MAC between the PF and VF.=A0 Allowing the guest to change the MAC= will require > synchronization between the hypervisor and the PF/VF drivers. Most of the= VF drivers > don't allow changing guest MAC unless it is a trusted VF. OK but it's a policy thing. Maybe it's a trusted VF. Who knows? For example I can see host just failing VIRTIO_NET_CTRL_MAC_ADDR_SET if it wants to block it. I'm not sure why VIRTIO_NET_F_STANDBY has to block it in the guest. -- = MST From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56604) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fXd7o-0002Hi-Ig for qemu-devel@nongnu.org; Mon, 25 Jun 2018 21:50:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fXd7j-0005VW-NR for qemu-devel@nongnu.org; Mon, 25 Jun 2018 21:50:32 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50412 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fXd7j-0005Ua-8w for qemu-devel@nongnu.org; Mon, 25 Jun 2018 21:50:27 -0400 Date: Tue, 26 Jun 2018 04:50:25 +0300 From: "Michael S. Tsirkin" Message-ID: <20180626044650-mutt-send-email-mst@kernel.org> References: <20180622053141-mutt-send-email-mst@kernel.org> <20180623002628-mutt-send-email-mst@kernel.org> <20180623012406-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [virtio-dev] Re: [PATCH] qemu: Introduce VIRTIO_NET_F_STANDBY feature bit to virtio_net List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Samudrala, Sridhar" Cc: Siwei Liu , Cornelia Huck , Alexander Duyck , virtio-dev@lists.oasis-open.org, aaron.f.brown@intel.com, Jiri Pirko , Jakub Kicinski , Netdev , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, Joao Martins , Venu Busireddy , vijay.balakrishna@oracle.com On Mon, Jun 25, 2018 at 10:54:09AM -0700, Samudrala, Sridhar wrote: > > > > > Might not neccessarily be something wrong, but it's very limite= d to > > > > > prohibit the MAC of VF from changing when enslaved by failover. > > > > You mean guest changing MAC? I'm not sure why we prohibit that. > > > I think Sridhar and Jiri might be better person to answer it. My > > > impression was that sync'ing the MAC address change between all 3 > > > devices is challenging, as the failover driver uses MAC address to > > > match net_device internally. >=20 > Yes. The MAC address is assigned by the hypervisor and it needs to mana= ge the movement > of the MAC between the PF and VF.=A0 Allowing the guest to change the M= AC will require > synchronization between the hypervisor and the PF/VF drivers. Most of t= he VF drivers > don't allow changing guest MAC unless it is a trusted VF. OK but it's a policy thing. Maybe it's a trusted VF. Who knows? For example I can see host just failing VIRTIO_NET_CTRL_MAC_ADDR_SET if it wants to block it. I'm not sure why VIRTIO_NET_F_STANDBY has to block it in the guest. --=20 MST From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-4531-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [66.179.20.138]) by lists.oasis-open.org (Postfix) with ESMTP id 14F395818086 for ; Mon, 25 Jun 2018 18:50:37 -0700 (PDT) Date: Tue, 26 Jun 2018 04:50:25 +0300 From: "Michael S. Tsirkin" Message-ID: <20180626044650-mutt-send-email-mst@kernel.org> References: <20180622053141-mutt-send-email-mst@kernel.org> <20180623002628-mutt-send-email-mst@kernel.org> <20180623012406-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: Subject: Re: [virtio-dev] Re: [Qemu-devel] [PATCH] qemu: Introduce VIRTIO_NET_F_STANDBY feature bit to virtio_net To: "Samudrala, Sridhar" Cc: Siwei Liu , Cornelia Huck , Alexander Duyck , virtio-dev@lists.oasis-open.org, aaron.f.brown@intel.com, Jiri Pirko , Jakub Kicinski , Netdev , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, Joao Martins , Venu Busireddy , vijay.balakrishna@oracle.com List-ID: On Mon, Jun 25, 2018 at 10:54:09AM -0700, Samudrala, Sridhar wrote: > > > > > Might not neccessarily be something wrong, but it's very limited = to > > > > > prohibit the MAC of VF from changing when enslaved by failover. > > > > You mean guest changing MAC? I'm not sure why we prohibit that. > > > I think Sridhar and Jiri might be better person to answer it. My > > > impression was that sync'ing the MAC address change between all 3 > > > devices is challenging, as the failover driver uses MAC address to > > > match net_device internally. >=20 > Yes. The MAC address is assigned by the hypervisor and it needs to manage= the movement > of the MAC between the PF and VF.=A0 Allowing the guest to change the MAC= will require > synchronization between the hypervisor and the PF/VF drivers. Most of the= VF drivers > don't allow changing guest MAC unless it is a trusted VF. OK but it's a policy thing. Maybe it's a trusted VF. Who knows? For example I can see host just failing VIRTIO_NET_CTRL_MAC_ADDR_SET if it wants to block it. I'm not sure why VIRTIO_NET_F_STANDBY has to block it in the guest. --=20 MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org