Messages in this thread | | | Subject | Re: [PATCH 2/3] vdpa/mlx5: Only return vq ready if vq is initialized | From | Jason Wang <> | Date | Tue, 1 Jun 2021 13:03:36 +0800 |
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在 2021/6/1 下午12:13, Eli Cohen 写道: > On Tue, Jun 01, 2021 at 10:18:04AM +0800, Jason Wang wrote: >> 在 2021/6/1 上午12:04, Eli Cohen 写道: >>> Only return the value of the ready field if the VQ is initialized in >>> which case the value of the field is valid. >>> >>> Failing to do so can result in virtio_vdpa failing to load if the device >>> was previously used by vhost_vdpa and the old values are ready. >>> virtio_vdpa expects to find VQs in "not ready" state. >>> >>> Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices") >>> Signed-off-by: Eli Cohen <elic@nvidia.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 02a05492204c..f6b680d2ab1c 100644 >>> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c >>> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c >>> @@ -1407,7 +1407,7 @@ static bool mlx5_vdpa_get_vq_ready(struct vdpa_device *vdev, u16 idx) >>> struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev); >>> struct mlx5_vdpa_virtqueue *mvq = &ndev->vqs[idx]; >>> - return mvq->ready; >>> + return mvq->initialized && mvq->ready; >> >> I think the more suitable fix is to reset mvq->ready during reset. The >> vq_ready should follow the queue_enable semantic in virtio-pci: >> >> " >> The device MUST present a 0 in queue_enable on reset. >> " > Thinking again, I think we should call set_vq_ready() from > qemu/virtio_vdpa etc. after reset to explicitly set ready to false.
This is not what I read from the spec and how the current driver behave.
And I don't see why we need to stick to 1 after the reset.
> > The ready indication is not necessairily a reflection of the hardware > queue: > > "Virtual queue ready bit > Writing one (0x1) to this register notifies the device that it can > execute requests from this virtual queue. Reading from this register > returns the last value written to it. Both read and write accesses apply > to the queue selected by writing to QueueSel."
My understanding that this applies if not reset in the middle. We can clarify this in the spec if needed.
Thanks
> > >> Thanks >> >> >>> } >>> static int mlx5_vdpa_set_vq_state(struct vdpa_device *vdev, u16 idx,
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