From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH net-next v2 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor Date: Wed, 3 Jan 2018 16:01:55 +0200 Message-ID: <20180103155026-mutt-send-email-mst@kernel.org> References: <44da522ecee60792ec918234ee4d61a84e4574f0.1513974243.git.jbaron@akamai.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, qemu-devel@nongnu.org, jasowang@redhat.com To: Jason Baron Return-path: Received: from mx1.redhat.com ([209.132.183.28]:52746 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752082AbeACOB5 (ORCPT ); Wed, 3 Jan 2018 09:01:57 -0500 Content-Disposition: inline In-Reply-To: <44da522ecee60792ec918234ee4d61a84e4574f0.1513974243.git.jbaron@akamai.com> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, Dec 22, 2017 at 04:54:01PM -0500, Jason Baron wrote: > The ability to set speed and duplex for virtio_net in useful in various > scenarios as described here: > > 16032be virtio_net: add ethtool support for set and get of settings > > However, it would be nice to be able to set this from the hypervisor, > such that virtio_net doesn't require custom guest ethtool commands. > > Introduce a new feature flag, VIRTIO_NET_F_SPEED_DUPLEX, which allows > the hypervisor to export a linkspeed and duplex setting. The user can > subsequently overwrite it later if desired via: 'ethtool -s'. > > Signed-off-by: Jason Baron > Cc: "Michael S. Tsirkin" > Cc: Jason Wang > --- > drivers/net/virtio_net.c | 17 ++++++++++++++++- > include/uapi/linux/virtio_net.h | 5 +++++ > 2 files changed, 21 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 511f833..4168d82 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -2621,6 +2621,20 @@ static int virtnet_probe(struct virtio_device *vdev) > netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs); > > virtnet_init_settings(dev); > + if (virtio_has_feature(vdev, VIRTIO_NET_F_SPEED_DUPLEX)) { > + u32 speed; > + u8 duplex; > + > + speed = virtio_cread32(vdev, offsetof(struct virtio_net_config, > + speed)); > + if (ethtool_validate_speed(speed)) > + vi->speed = speed; > + duplex = virtio_cread8(vdev, > + offsetof(struct virtio_net_config, > + duplex)); > + if (ethtool_validate_duplex(duplex)) > + vi->duplex = duplex; > + } > > err = register_netdev(dev); > if (err) { It would seem that speed/duplex can change at link up time. Update it from virtnet_config_changed_work please. > @@ -2746,7 +2760,8 @@ static struct virtio_device_id id_table[] = { > VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \ > VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \ > VIRTIO_NET_F_CTRL_MAC_ADDR, \ > - VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS > + VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \ > + VIRTIO_NET_F_SPEED_DUPLEX > > static unsigned int features[] = { > VIRTNET_FEATURES, > diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h > index fc353b5..0f1548e 100644 > --- a/include/uapi/linux/virtio_net.h > +++ b/include/uapi/linux/virtio_net.h > @@ -57,6 +57,8 @@ > * Steering */ > #define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */ > > +#define VIRTIO_NET_F_SPEED_DUPLEX 63 /* Host set linkspeed and duplex */ > + Host -> device, to match virtio spec terminology. > #ifndef VIRTIO_NET_NO_LEGACY > #define VIRTIO_NET_F_GSO 6 /* Host handles pkts w/ any GSO type */ > #endif /* VIRTIO_NET_NO_LEGACY */ > @@ -76,6 +78,9 @@ struct virtio_net_config { > __u16 max_virtqueue_pairs; > /* Default maximum transmit unit advice */ > __u16 mtu; > + /* Host exported linkspeed and duplex */ I would rather drop this and document each field. /* speed, in units of 1Mb. All values 0 to INT_MAX are legal. Any other value stands for unknown. */ > + __u32 speed; /* 0x00 - half duplex 0x01 - full duplex Any other value stands for unknown. */ > + __u8 duplex; > } __attribute__((packed)); > > /* > -- > 2.6.1