From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jianfeng Tan Subject: [PATCH] net/virtio-user: fix cannot get initialized Date: Fri, 7 Apr 2017 07:57:40 +0000 Message-ID: <1491551860-15005-1-git-send-email-jianfeng.tan@intel.com> Cc: Jianfeng Tan , Maxime Coquelin , Yuanhan Liu To: dev@dpdk.org Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 7F6922FDD for ; Fri, 7 Apr 2017 09:56:55 +0200 (CEST) List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" After the introduction of vhost MTU, VIRTIO_NET_F_MTU is enabled by default. However, virtio-user vtpci does not support to get MTU from device yet, i.e., vtpci_read_dev_config(MTU) fails. Plus, struct virtio_net_config is defined as a uninitialized variable, and could be different values in virtio_negotiate_features() and virtio_init_device(). In some cases, it passes the check in virtio_negotiate_features() but fails the check in virtio_init_device(). As a result, virtio-user canno be initialized. To fix it, (1) accessing uninitialized variable is not a good practice, so initialize it as zero; (2) explicitly disable MTU feature in virtio-user. Fixes: 49d26d9e3f47 ("net/virtio: support MTU feature") Cc: Maxime Coquelin Cc: Yuanhan Liu Signed-off-by: Jianfeng Tan --- drivers/net/virtio/virtio_ethdev.c | 4 ++-- drivers/net/virtio/virtio_user/virtio_user_dev.c | 6 ++++++ 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c index 78cb3e8..4c43784 100644 --- a/drivers/net/virtio/virtio_ethdev.c +++ b/drivers/net/virtio/virtio_ethdev.c @@ -1163,7 +1163,7 @@ virtio_negotiate_features(struct virtio_hw *hw, uint64_t req_features) /* If supported, ensure MTU value is valid before acknowledging it. */ if (host_features & req_features & (1ULL << VIRTIO_NET_F_MTU)) { - struct virtio_net_config config; + struct virtio_net_config config = {0}; vtpci_read_dev_config(hw, offsetof(struct virtio_net_config, mtu), @@ -1332,7 +1332,7 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features) { struct virtio_hw *hw = eth_dev->data->dev_private; struct virtio_net_config *config; - struct virtio_net_config local_config; + struct virtio_net_config local_config = {0}; struct rte_pci_device *pci_dev = NULL; int ret; diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c index 6871cd4..529b3d7 100644 --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c @@ -362,6 +362,12 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues, /* The backend will not report this feature, we add it explicitly */ dev->device_features |= (1ull << VIRTIO_NET_F_STATUS); + /* TODO: VIRTIO_NET_F_MTU is for QEMU to advertise MTU to both frontend + * and backend driver. For virtio-user, disable it for now, until we + * have a parameter to specify the MTU. + */ + dev->device_features &= ~(1ull << VIRTIO_NET_F_MTU); + return 0; } -- 2.7.4