Re: [PATCH v4 1/6] virtio-net: Stop doing DMA from the stack

[Andy Lutomirski]

On Fri, Oct 30, 2015 at 6:55 AM, Christian Borntraeger
<borntraeger@xxxxxxxxxx> wrote:
> Am 30.10.2015 um 02:09 schrieb Andy Lutomirski:
>> From: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
>>
>> Once virtio starts using the DMA API, we won't be able to safely DMA
>> from the stack.  virtio-net does a couple of config DMA requests
>> from small stack buffers -- switch to using dynamically-allocated
>> memory.
>>
>> This should have no effect on any performance-critical code paths.
>>
>> [I wrote the subject and commit message.  mst wrote the code. --luto]
>>
>> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
>> signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
>
> I still get an error when using multiqueue:
>
> #  ethtool -L eth0 combined 4
> [   33.534686] virtio_ccw 0.0.000d: DMA-API: device driver maps memory from stack [addr=00000000629e7c06]

Fixed in my branch, I think.

--Andy
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