From 3f3b3d549bd5f308aaf425a9ab58473e4fb812b1 Mon Sep 17 00:00:00 2001 From: Yuanhan Liu Date: Sat, 5 Nov 2016 17:40:56 +0800 Subject: [PATCH] net/virtio: revert fix restart This reverts commit 9a0615af7746 ("virtio: fix restart"); conflict is manually addressed. Kyle reported an issue with above commit qemu-kvm: Guest moved used index from 5 to 1 with following steps, 1) Start my virtio interfaces 2) Send some traffic into/out of the interfaces 3) Stop the interfaces 4) Start the interfaces 5) Send some more traffic And here are some quotes from Kyle's analysis, Prior to the patch, if an interface were stopped then started, without restarting the application, the queues would be left as-is, because hw->started would be set to 1. Now, calling stop sets hw->started to 0, which means the next call to start will "touch the queues". This is the unintended side-effect that causes the problem. We should not touch the queues once the init is done, otherwise, the vring state of virtio PMD driver and vhost-user would be inconsistent, leading some issue like above. Thus this patch is reverted. Fixes: 9a0615af7746 ("virtio: fix restart") Reported-by: Kyle Larose Signed-off-by: Yuanhan Liu Reviewed-by: Maxime Coquelin --- drivers/net/virtio/virtio_ethdev.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c index b3881340e9..5815875aab 100644 --- a/drivers/net/virtio/virtio_ethdev.c +++ b/drivers/net/virtio/virtio_ethdev.c @@ -550,9 +550,6 @@ virtio_dev_close(struct rte_eth_dev *dev) PMD_INIT_LOG(DEBUG, "virtio_dev_close"); - if (hw->started == 1) - virtio_dev_stop(dev); - if (hw->cvq) virtio_dev_queue_release(hw->cvq->vq); @@ -560,6 +557,7 @@ virtio_dev_close(struct rte_eth_dev *dev) if (dev->data->dev_flags & RTE_ETH_DEV_INTR_LSC) vtpci_irq_config(hw, VIRTIO_MSI_NO_VECTOR); vtpci_reset(hw); + hw->started = 0; virtio_dev_free_mbufs(dev); virtio_free_queues(dev); } @@ -1296,15 +1294,17 @@ static int eth_virtio_dev_uninit(struct rte_eth_dev *eth_dev) { struct rte_pci_device *pci_dev; + struct virtio_hw *hw = eth_dev->data->dev_private; PMD_INIT_FUNC_TRACE(); if (rte_eal_process_type() == RTE_PROC_SECONDARY) return -EPERM; - /* Close it anyway since there's no way to know if closed */ - virtio_dev_close(eth_dev); - + if (hw->started == 1) { + virtio_dev_stop(eth_dev); + virtio_dev_close(eth_dev); + } pci_dev = eth_dev->pci_dev; eth_dev->dev_ops = NULL; @@ -1543,12 +1543,9 @@ static void virtio_dev_stop(struct rte_eth_dev *dev) { struct rte_eth_link link; - struct virtio_hw *hw = dev->data->dev_private; PMD_INIT_LOG(DEBUG, "stop"); - hw->started = 0; - if (dev->data->dev_conf.intr_conf.lsc) rte_intr_disable(&dev->pci_dev->intr_handle); -- 2.20.1