From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sridhar Samudrala Subject: [PATCH net-next v9 3/4] virtio_net: Extend virtio to use VF datapath when available Date: Fri, 27 Apr 2018 10:06:59 -0700 Message-ID: <1524848820-42258-4-git-send-email-sridhar.samudrala__37687.4125250199$1524848716$gmane$org@intel.com> References: <1524848820-42258-1-git-send-email-sridhar.samudrala@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1524848820-42258-1-git-send-email-sridhar.samudrala@intel.com> 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 To: mst@redhat.com, stephen@networkplumber.org, davem@davemloft.net, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, virtio-dev@lists.oasis-open.org, jesse.brandeburg@intel.com, alexander.h.duyck@intel.com, kubakici@wp.pl, sridhar.samudrala@intel.com, jasowang@redhat.com, loseweigh@gmail.com, jiri@resnulli.us, aaron.f.brown@intel.com List-Id: virtualization@lists.linuxfoundation.org This patch enables virtio_net to switch over to a VF datapath when a VF netdev is present with the same MAC address. It allows live migration of a VM with a direct attached VF without the need to setup a bond/team between a VF and virtio net device in the guest. The hypervisor needs to enable only one datapath at any time so that packets don't get looped back to the VM over the other datapath. When a VF is plugged, the virtio datapath link state can be marked as down. The hypervisor needs to unplug the VF device from the guest on the source host and reset the MAC filter of the VF to initiate failover of datapath to virtio before starting the migration. After the migration is completed, the destination hypervisor sets the MAC filter on the VF and plugs it back to the guest to switch over to VF datapath. It uses the generic failover framework that provides 2 functions to create and destroy a master failover netdev. When STANDBY feature is enabled, an additional netdev(failover netdev) is created that acts as a master device and tracks the state of the 2 lower netdevs. The original virtio_net netdev is marked as 'standby' netdev and a passthru device with the same MAC is registered as 'primary' netdev. This patch is based on the discussion initiated by Jesse on this thread. https://marc.info/?l=linux-virtualization&m=151189725224231&w=2 Signed-off-by: Sridhar Samudrala --- drivers/net/Kconfig | 1 + drivers/net/virtio_net.c | 35 ++++++++++++++++++++++++++++++++++- 2 files changed, 35 insertions(+), 1 deletion(-) diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index 891846655000..c4995625d9b1 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -331,6 +331,7 @@ config VETH config VIRTIO_NET tristate "Virtio network driver" depends on VIRTIO + select NET_FAILOVER ---help--- This is the virtual network driver for virtio. It can be used with QEMU based VMMs (like KVM or Xen). Say Y or M. diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 51a085b1a242..c326ee5344c0 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -30,8 +30,11 @@ #include #include #include +#include +#include #include #include +#include static int napi_weight = NAPI_POLL_WEIGHT; module_param(napi_weight, int, 0444); @@ -210,6 +213,9 @@ struct virtnet_info { u32 speed; unsigned long guest_offloads; + + /* failover when STANDBY feature enabled */ + struct net_failover *failover; }; struct padded_vnet_hdr { @@ -2306,6 +2312,22 @@ static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp) } } +static int virtnet_get_phys_port_name(struct net_device *dev, char *buf, + size_t len) +{ + struct virtnet_info *vi = netdev_priv(dev); + int ret; + + if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY)) + return -EOPNOTSUPP; + + ret = snprintf(buf, len, "_sby"); + if (ret >= len) + return -EOPNOTSUPP; + + return 0; +} + static const struct net_device_ops virtnet_netdev = { .ndo_open = virtnet_open, .ndo_stop = virtnet_close, @@ -2323,6 +2345,7 @@ static const struct net_device_ops virtnet_netdev = { .ndo_xdp_xmit = virtnet_xdp_xmit, .ndo_xdp_flush = virtnet_xdp_flush, .ndo_features_check = passthru_features_check, + .ndo_get_phys_port_name = virtnet_get_phys_port_name, }; static void virtnet_config_changed_work(struct work_struct *work) @@ -2876,10 +2899,16 @@ static int virtnet_probe(struct virtio_device *vdev) virtnet_init_settings(dev); + if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) { + err = net_failover_create(vi->dev, &vi->failover); + if (err) + goto free_vqs; + } + err = register_netdev(dev); if (err) { pr_debug("virtio_net: registering device failed\n"); - goto free_vqs; + goto free_failover; } virtio_device_ready(vdev); @@ -2916,6 +2945,8 @@ static int virtnet_probe(struct virtio_device *vdev) vi->vdev->config->reset(vdev); unregister_netdev(dev); +free_failover: + net_failover_destroy(vi->failover); free_vqs: cancel_delayed_work_sync(&vi->refill); free_receive_page_frags(vi); @@ -2950,6 +2981,8 @@ static void virtnet_remove(struct virtio_device *vdev) unregister_netdev(vi->dev); + net_failover_destroy(vi->failover); + remove_vq_common(vi); free_netdev(vi->dev); -- 2.14.3