On Tue, Mar 19, 2024 at 2:56 PM Michael S. Tsirkin [off-list ref] wrote:

On Tue, Mar 12, 2024 at 11:35:47AM +0800, Xuan Zhuo wrote:

quoted

As discussed:

http://lore.kernel.org/all/CACGkMEvq0No8QGC46U4mGsMtuD44fD_cfLcPaVmJ3rHYqRZxYg@mail.gmail.com (local)

If the virtio is premapped mode, the driver should manage the dma info by self.
So the virtio core should not store the dma info. We can release the memory used
to store the dma info.

For virtio-net xmit queue, if the virtio-net maintains the dma info,
the virtio-net must allocate too much memory(19 * queue_size for per-queue), so
we do not plan to make the virtio-net to maintain the dma info by default. The
virtio-net xmit queue only maintain the dma info when premapped mode is enable
(such as AF_XDP is enable).

This landed when merge window was open already so I'm deferring this
to the next merge window, just to be safe. Jason can you review please?

Will do.

Thanks