From 283e2c2adcb80148c7f67d71d52134af80d2fbae Mon Sep 17 00:00:00 2001 From: Yuri Benditovich Date: Tue, 13 Dec 2016 10:12:08 +0200 Subject: net: virtio-net discards TX data after link down https://bugzilla.redhat.com/show_bug.cgi?id=1295637 Upon set_link monitor command or upon netdev deletion virtio-net sends link down indication to the guest and stops vhost if one is used. Guest driver can still submit data for TX until it recognizes link loss. If these packets not returned by the host, the Windows guest will never be able to finish disable/removal/shutdown. Now each packet sent by guest after NIC indicated link down will be completed immediately. Signed-off-by: Yuri Benditovich Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/net/virtio-net.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'hw/net/virtio-net.c') diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 5009533cfa..6f98eab2ba 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -218,6 +218,14 @@ static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t status) } } +static void virtio_net_drop_tx_queue_data(VirtIODevice *vdev, VirtQueue *vq) +{ + unsigned int dropped = virtqueue_drop_all(vq); + if (dropped) { + virtio_notify(vdev, vq); + } +} + static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status) { VirtIONet *n = VIRTIO_NET(vdev); @@ -262,6 +270,14 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status) } else { qemu_bh_cancel(q->tx_bh); } + if ((n->status & VIRTIO_NET_S_LINK_UP) == 0 && + (queue_status & VIRTIO_CONFIG_S_DRIVER_OK)) { + /* if tx is waiting we are likely have some packets in tx queue + * and disabled notification */ + q->tx_waiting = 0; + virtio_queue_set_notification(q->tx_vq, 1); + virtio_net_drop_tx_queue_data(vdev, q->tx_vq); + } } } } @@ -1323,6 +1339,11 @@ static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq) VirtIONet *n = VIRTIO_NET(vdev); VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))]; + if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) { + virtio_net_drop_tx_queue_data(vdev, vq); + return; + } + /* This happens when device was stopped but VCPU wasn't. */ if (!vdev->vm_running) { q->tx_waiting = 1; @@ -1349,6 +1370,11 @@ static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq) VirtIONet *n = VIRTIO_NET(vdev); VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))]; + if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) { + virtio_net_drop_tx_queue_data(vdev, vq); + return; + } + if (unlikely(q->tx_waiting)) { return; } -- cgit v1.2.3-55-g7522 From a93e599d4a04c3cf7edcf5a24f3397e27431c027 Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Sat, 10 Dec 2016 16:30:38 +0100 Subject: virtio-net: Add MTU feature support This patch allows advising guest with host MTU's by setting host_mtu parameter. If VIRTIO_NET_F_MTU has been successfully negotiated, MTU value is passed to the backend. Cc: Michael S. Tsirkin Cc: Aaron Conole Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/net/virtio-net.c | 19 +++++++++++++++++++ include/hw/virtio/virtio-net.h | 1 + 2 files changed, 20 insertions(+) (limited to 'hw/net/virtio-net.c') diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 6f98eab2ba..7b3ad4a9f0 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -55,6 +55,8 @@ static VirtIOFeature feature_sizes[] = { .end = endof(struct virtio_net_config, status)}, {.flags = 1 << VIRTIO_NET_F_MQ, .end = endof(struct virtio_net_config, max_virtqueue_pairs)}, + {.flags = 1 << VIRTIO_NET_F_MTU, + .end = endof(struct virtio_net_config, mtu)}, {} }; @@ -81,6 +83,7 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config) virtio_stw_p(vdev, &netcfg.status, n->status); virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queues); + virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu); memcpy(netcfg.mac, n->mac, ETH_ALEN); memcpy(config, &netcfg, n->config_size); } @@ -152,6 +155,16 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status) qemu_net_queue_purge(qnc->incoming_queue, qnc->peer); } + if (virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_MTU)) { + r = vhost_net_set_mtu(get_vhost_net(nc->peer), n->net_conf.mtu); + if (r < 0) { + error_report("%uBytes MTU not supported by the backend", + n->net_conf.mtu); + + return; + } + } + n->vhost_started = 1; r = vhost_net_start(vdev, n->nic->ncs, queues); if (r < 0) { @@ -1721,6 +1734,7 @@ static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features) { int i, config_size = 0; virtio_add_feature(&host_features, VIRTIO_NET_F_MAC); + for (i = 0; feature_sizes[i].flags != 0; i++) { if (host_features & feature_sizes[i].flags) { config_size = MAX(feature_sizes[i].end, config_size); @@ -1750,6 +1764,10 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) NetClientState *nc; int i; + if (n->net_conf.mtu) { + n->host_features |= (0x1 << VIRTIO_NET_F_MTU); + } + virtio_net_set_config_size(n, n->host_features); virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size); @@ -1948,6 +1966,7 @@ static Property virtio_net_properties[] = { DEFINE_PROP_STRING("tx", VirtIONet, net_conf.tx), DEFINE_PROP_UINT16("rx_queue_size", VirtIONet, net_conf.rx_queue_size, VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE), + DEFINE_PROP_UINT16("host_mtu", VirtIONet, net_conf.mtu, 0), DEFINE_PROP_END_OF_LIST(), }; diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h index 0ced975c57..8ea56a8f60 100644 --- a/include/hw/virtio/virtio-net.h +++ b/include/hw/virtio/virtio-net.h @@ -36,6 +36,7 @@ typedef struct virtio_net_conf int32_t txburst; char *tx; uint16_t rx_queue_size; + uint16_t mtu; } virtio_net_conf; /* Maximum packet size we can receive from tap device: header + 64k */ -- cgit v1.2.3-55-g7522