Re: [PATCH] swiotlb: Validate bounce size in the sync/unmap path

From: Christoph Hellwig
Date: Tue Feb 09 2021 - 03:28:09 EST


On Mon, Feb 08, 2021 at 12:14:49PM -0500, Konrad Rzeszutek Wilk wrote:
> > ring buffer or whatever because you know I/O will be copied anyway
> > and none of all the hard work higher layers do to make the I/O suitable
> > for a normal device apply.
>
> I lost you here. Sorry, are you saying have a simple ring protocol
> (like NVME has), where the ring entries (SG or DMA phys) are statically
> allocated and whenever NVME driver gets data from user-space it
> would copy it in there?

Yes. Basically extend the virtio or NVMe ring/queue concept to not just
cover commands and completions, but also the data transfers.