On 2021/2/2 上午3:17, Si-Wei Liu wrote:
On Mon, Feb 1, 2021 at 10:51 AM Si-Wei Liu <siwliu.kernel@xxxxxxxxx> wrote:
On Thu, Jan 28, 2021 at 5:46 AM Eli Cohen <elic@xxxxxxxxxx> wrote:
suspend_vq should only suspend the VQ on not save the current available
index. This is done when a change of map occurs when the driver calls
save_channel_info().
Hmmm, suspend_vq() is also called by teardown_vq(), the latter of
which doesn't save the available index as save_channel_info() doesn't
get called in that path at all. How does it handle the case that
aget_vq_state() is called from userspace (e.g. QEMU) while the
hardware VQ object was torn down, but userspace still wants to access
the queue index?
Refer to https://lore.kernel.org/netdev/1601583511-15138-1-git-send-email-si-wei.liu@xxxxxxxxxx/
vhost VQ 0 ring restore failed: -1: Resource temporarily unavailable (11)
vhost VQ 1 ring restore failed: -1: Resource temporarily unavailable (11)
QEMU will complain with the above warning while VM is being rebooted
or shut down.
Looks to me either the kernel driver should cover this requirement, or
the userspace has to bear the burden in saving the index and not call
into kernel if VQ is destroyed.
Actually, the userspace doesn't have the insights whether virt queue
will be destroyed if just changing the device status via set_status().
Looking at other vdpa driver in tree i.e. ifcvf it doesn't behave like
so. Hence this still looks to me to be Mellanox specifics and
mlx5_vdpa implementation detail that shouldn't expose to userspace.
So I think we can simply drop this patch?
Thanks
-Siwei
Signed-off-by: Eli Cohen <elic@xxxxxxxxxx>
---
drivers/vdpa/mlx5/net/mlx5_vnet.c | 8 --------
1 file changed, 8 deletions(-)
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 88dde3455bfd..549ded074ff3 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1148,8 +1148,6 @@ static int setup_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
static void suspend_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
{
- struct mlx5_virtq_attr attr;
-
if (!mvq->initialized)
return;
@@ -1158,12 +1156,6 @@ static void suspend_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *m
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)
--
2.29.2
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