From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55718) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eX8yM-0006fJ-F3 for qemu-devel@nongnu.org; Thu, 04 Jan 2018 12:06:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eX8xr-0002yu-Td for qemu-devel@nongnu.org; Thu, 04 Jan 2018 12:06:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54858) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eX8xr-0002vy-CQ for qemu-devel@nongnu.org; Thu, 04 Jan 2018 12:05:59 -0500 Date: Thu, 4 Jan 2018 19:05:56 +0200 From: "Michael S. Tsirkin" Message-ID: <20180104190309-mutt-send-email-mst@kernel.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH net-next v3 1/3] virtio_net: propagate linkspeed/duplex settings from the hypervisor List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jason Baron Cc: davem@davemloft.net, jasowang@redhat.com, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org On Thu, Jan 04, 2018 at 12:16:44AM -0500, Jason Baron wrote: > The ability to set speed and duplex for virtio_net is 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'. > > Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention > is that device feature bits are to grow down from bit 63, since the > transports are starting from bit 24 and growing up. > > Signed-off-by: Jason Baron > Cc: "Michael S. Tsirkin" > Cc: Jason Wang > Cc: virtio-dev@lists.oasis-open.org > --- > drivers/net/virtio_net.c | 19 ++++++++++++++++++- > include/uapi/linux/virtio_net.h | 13 +++++++++++++ > 2 files changed, 31 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 6fb7b65..0b2d314 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -2146,6 +2146,22 @@ static void virtnet_config_changed_work(struct work_struct *work) > > vi->status = v; > > + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX)) { BTW we can avoid this read for when link goes down. Not a big deal but still. > + u32 speed; > + u8 duplex; > + > + speed = virtio_cread32(vi->vdev, > + offsetof(struct virtio_net_config, > + speed)); > + if (ethtool_validate_speed(speed)) > + vi->speed = speed; > + duplex = virtio_cread8(vi->vdev, > + offsetof(struct virtio_net_config, > + duplex)); > + if (ethtool_validate_duplex(duplex)) > + vi->duplex = duplex; > + } > + > if (vi->status & VIRTIO_NET_S_LINK_UP) { > netif_carrier_on(vi->dev); > netif_tx_wake_all_queues(vi->dev); OK so this handles the case when VIRTIO_NET_F_STATUS is set, but when it's clear we need to call this from virtnet_probe. I propose moving this chunk to a function and calling from two places. > @@ -2796,7 +2812,8 @@ 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..5de6ed3 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 /* Device set linkspeed and duplex */ > + > #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 +78,17 @@ struct virtio_net_config { > __u16 max_virtqueue_pairs; > /* Default maximum transmit unit advice */ > __u16 mtu; > + /* > + * 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