Re: [PATCH] vdpa/mlx5: should keep avail_index despite device status
From: Jason Wang <hidden>
Date: 2020-10-10 07:34:27
Also in:
lkml, virtualization
On 2020/10/2 上午4:18, Si-Wei Liu wrote:
A VM with mlx5 vDPA has below warnings while being reset: vhost VQ 0 ring restore failed: -1: Resource temporarily unavailable (11) vhost VQ 1 ring restore failed: -1: Resource temporarily unavailable (11) We should allow userspace emulating the virtio device be able to get to vq's avail_index, regardless of vDPA device status. Save the index that was last seen when virtq was stopped, so that userspace doesn't complain. Signed-off-by: Si-Wei Liu <redacted>
Acked-by: Jason Wang <redacted>
quoted hunk ↗ jump to hunk
--- drivers/vdpa/mlx5/net/mlx5_vnet.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index 70676a6..74264e59 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c@@ -1133,15 +1133,17 @@ static void suspend_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *m if (!mvq->initialized) return; - if (query_virtqueue(ndev, mvq, &attr)) { - mlx5_vdpa_warn(&ndev->mvdev, "failed to query virtqueue\n"); - return; - } if (mvq->fw_state != MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY) return; if (modify_virtqueue(ndev, mvq, MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND)) mlx5_vdpa_warn(&ndev->mvdev, "modify to suspend failed\n"); + + if (query_virtqueue(ndev, mvq, &attr)) { + mlx5_vdpa_warn(&ndev->mvdev, "failed to query virtqueue\n"); + return; + } + mvq->avail_idx = attr.available_index; } static void suspend_vqs(struct mlx5_vdpa_net *ndev)@@ -1411,8 +1413,14 @@ static int mlx5_vdpa_get_vq_state(struct vdpa_device *vdev, u16 idx, struct vdpa struct mlx5_virtq_attr attr; int err; - if (!mvq->initialized) - return -EAGAIN; + /* If the virtq object was destroyed, use the value saved at + * the last minute of suspend_vq. This caters for userspace + * that cares about emulating the index after vq is stopped. + */ + if (!mvq->initialized) { + state->avail_index = mvq->avail_idx; + return 0; + } err = query_virtqueue(ndev, mvq, &attr); if (err) {