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Date: Thu, 20 Jul 2023 01:21:43 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Jason Wang <jasowang@redhat.com>
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Subject: Re: [PATCH vhost v11 10/10] virtio_net: merge dma operation for one
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	lindbergh.monkeyblade.net

On Thu, Jul 20, 2023 at 03:41:56PM +0800, Jason Wang wrote:
> > Did you actually check that it works though?
> > Looks like with swiotlb you need to synch to trigger a copy
> > before unmap, and I don't see where it's done in the current
> > patch.
> 
> And this is needed for XDP_REDIRECT as well.

DMA always needs proper syncs, be that for swiotlb or for cache
maintainance, yes.