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Subject: Re: [PATCH] vdpa/mlx5: Clear vq ready indication upon device reset
From:   Jason Wang <jasowang@redhat.com>
To:     Eli Cohen <elic@nvidia.com>, mst@redhat.com,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
References: <20210602085924.62777-1-elic@nvidia.com>
 <6e4f9e1b-2c67-fae6-6edd-1982d0f48e22@redhat.com>
Message-ID: <782562f2-6903-68cb-d753-ac90aea854e4@redhat.com>
Date:   Thu, 3 Jun 2021 15:06:31 +0800
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在 2021/6/3 下午3:00, Jason Wang 写道:
>
> 在 2021/6/2 下午4:59, Eli Cohen 写道:
>> After device reset, the virtqueues are not ready so clear the ready
>> field.
>>
>> 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>
>
>
> Acked-by: Jason Wang <jasowang@redhat.com>


A second thought.

destroy_virtqueue() could be called many places.

One of them is the mlx5_vdpa_change_map(), if this is case, this looks 
wrong.

It looks to me it's simpler to do this in clear_virtqueues() which can 
only be called during reset.

Thanks


>
>
>> ---
>>   drivers/vdpa/mlx5/net/mlx5_vnet.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c 
>> b/drivers/vdpa/mlx5/net/mlx5_vnet.c
>> index 02a05492204c..e8bc0842b44c 100644
>> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
>> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
>> @@ -862,6 +862,7 @@ static void destroy_virtqueue(struct 
>> mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtq
>>           return;
>>       }
>>       umems_destroy(ndev, mvq);
>> +    mvq->ready = false;
>>   }
>>     static u32 get_rqpn(struct mlx5_vdpa_virtqueue *mvq, bool fw)