From: Si-Wei Liu <si-wei.liu@oracle.com> To: mst@redhat.com, jasowang@redhat.com, elic@nvidia.com Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, si-wei.liu@oracle.com Subject: [PATCH v2 3/3] vdpa/mlx5: defer clear_virtqueues to until DRIVER_OK Date: Wed, 10 Feb 2021 13:48:00 -0800 (PST) [thread overview] Message-ID: <1612993680-29454-4-git-send-email-si-wei.liu@oracle.com> (raw) In-Reply-To: <1612993680-29454-1-git-send-email-si-wei.liu@oracle.com> While virtq is stopped, get_vq_state() is supposed to be called to get sync'ed with the latest internal avail_index from device. The saved avail_index is used to restate the virtq once device is started. Commit b35ccebe3ef7 introduced the clear_virtqueues() routine to reset the saved avail_index, however, the index gets cleared a bit earlier before get_vq_state() tries to read it. This would cause consistency problems when virtq is restarted, e.g. through a series of link down and link up events. We could defer the clearing of avail_index to until the device is to be started, i.e. until VIRTIO_CONFIG_S_DRIVER_OK is set again in set_status(). Fixes: b35ccebe3ef7 ("vdpa/mlx5: Restore the hardware used index after change map") Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com> Acked-by: Jason Wang <jasowang@redhat.com> --- drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index 7c1f789..ce6aae8 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -1777,7 +1777,6 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status) if (!status) { mlx5_vdpa_info(mvdev, "performing device reset\n"); teardown_driver(ndev); - clear_virtqueues(ndev); mlx5_vdpa_destroy_mr(&ndev->mvdev); ndev->mvdev.status = 0; ++mvdev->generation; @@ -1786,6 +1785,7 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status) if ((status ^ ndev->mvdev.status) & VIRTIO_CONFIG_S_DRIVER_OK) { if (status & VIRTIO_CONFIG_S_DRIVER_OK) { + clear_virtqueues(ndev); err = setup_driver(ndev); if (err) { mlx5_vdpa_warn(mvdev, "failed to setup driver\n"); -- 1.8.3.1
WARNING: multiple messages have this Message-ID (diff)
From: Si-Wei Liu <si-wei.liu@oracle.com> To: mst@redhat.com, jasowang@redhat.com, elic@nvidia.com Cc: si-wei.liu@oracle.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v2 3/3] vdpa/mlx5: defer clear_virtqueues to until DRIVER_OK Date: Wed, 10 Feb 2021 13:48:00 -0800 (PST) [thread overview] Message-ID: <1612993680-29454-4-git-send-email-si-wei.liu@oracle.com> (raw) In-Reply-To: <1612993680-29454-1-git-send-email-si-wei.liu@oracle.com> While virtq is stopped, get_vq_state() is supposed to be called to get sync'ed with the latest internal avail_index from device. The saved avail_index is used to restate the virtq once device is started. Commit b35ccebe3ef7 introduced the clear_virtqueues() routine to reset the saved avail_index, however, the index gets cleared a bit earlier before get_vq_state() tries to read it. This would cause consistency problems when virtq is restarted, e.g. through a series of link down and link up events. We could defer the clearing of avail_index to until the device is to be started, i.e. until VIRTIO_CONFIG_S_DRIVER_OK is set again in set_status(). Fixes: b35ccebe3ef7 ("vdpa/mlx5: Restore the hardware used index after change map") Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com> Acked-by: Jason Wang <jasowang@redhat.com> --- drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index 7c1f789..ce6aae8 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -1777,7 +1777,6 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status) if (!status) { mlx5_vdpa_info(mvdev, "performing device reset\n"); teardown_driver(ndev); - clear_virtqueues(ndev); mlx5_vdpa_destroy_mr(&ndev->mvdev); ndev->mvdev.status = 0; ++mvdev->generation; @@ -1786,6 +1785,7 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status) if ((status ^ ndev->mvdev.status) & VIRTIO_CONFIG_S_DRIVER_OK) { if (status & VIRTIO_CONFIG_S_DRIVER_OK) { + clear_virtqueues(ndev); err = setup_driver(ndev); if (err) { mlx5_vdpa_warn(mvdev, "failed to setup driver\n"); -- 1.8.3.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2021-02-10 21:51 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-02-10 21:47 [PATCH v2 0/3] mlx5_vdpa bug fixes Si-Wei Liu 2021-02-10 21:47 ` Si-Wei Liu 2021-02-10 21:47 ` [PATCH v2 1/3] vdpa/mlx5: should exclude header length and fcs from mtu Si-Wei Liu 2021-02-10 21:47 ` Si-Wei Liu 2021-02-10 21:47 ` [PATCH v2 2/3] vdpa/mlx5: fix feature negotiation across device reset Si-Wei Liu 2021-02-10 21:47 ` Si-Wei Liu 2021-02-11 7:33 ` Eli Cohen 2021-02-18 6:36 ` Jason Wang 2021-02-18 6:36 ` Jason Wang 2021-02-10 21:48 ` Si-Wei Liu [this message] 2021-02-10 21:48 ` [PATCH v2 3/3] vdpa/mlx5: defer clear_virtqueues to until DRIVER_OK Si-Wei Liu 2021-02-11 7:33 ` Eli Cohen 2021-02-16 15:21 ` Eli Cohen 2021-02-17 21:55 ` Si-Wei Liu 2021-02-17 21:55 ` Si-Wei Liu 2021-02-18 6:37 ` Jason Wang 2021-02-18 6:37 ` Jason Wang
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