On Wed, Mar 30, 2022 at 05:03:32PM +0800, Xuan Zhuo wrote:

On Wed, 30 Mar 2022 16:38:18 +0800, Jason Wang [off-list ref] wrote:

quoted

On Wed, Mar 30, 2022 at 2:59 PM Xuan Zhuo [off-list ref] wrote:

quoted

On Wed, 30 Mar 2022 14:56:17 +0800, Jason Wang [off-list ref] wrote:

quoted

On Wed, Mar 30, 2022 at 2:34 PM Michael S. Tsirkin [off-list ref] wrote:

quoted

On Thu, Feb 24, 2022 at 07:03:53PM +0800, Xuan Zhuo wrote:

quoted

virtqueue_add() only supports virtual addresses, dma is completed in
virtqueue_add().

In some scenarios (such as the AF_XDP scenario), DMA is completed in advance, so
it is necessary for us to support passing the DMA address to virtqueue_add().

I picked up a couple of patches. Others are waiting for some acks
(Jason?) and improved commit logs for documentation.

I will review them.

hi, the core code of premapped, I will merge it into 'virtio pci support
VIRTIO_F_RING_RESET' because this function will be used when reusing the buffer
after resize.

I still prefer not to do that.

We can make rest work for resize first and add pre mapping on top. It
will simplify the review.

Yes, I am also worried about the review problem, the number of my local resize
patch has reached 44 (including reuse bufs).

hi, Michael, can we implement resize on top of v8 first? (drop unused bufs directly)

Then we implement premmapd and reuse the bufs after resize.

We need to get the address (DMA address) and len from the reset ring and submit
it to the new vq through virtqueue_add(). So let virtqueue_add() support
premapped first.

Thanks.

Not sure I understand.
So the plan is
- remap
- resize on top
?

quoted

Thanks

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Thanks.

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Thanks

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Thanks!

quoted

v2:
    1. rename predma -> premapped
    2. virtio net xdp tx use virtio dma api

v1:
   1. All sgs requested at one time are required to be unified PREDMA, and several
      of them are not supported to be PREDMA
   2. virtio_dma_map() is removed from this patch set and will be submitted
      together with the next time AF_XDP supports virtio dma
   3. Added patch #2 #3 to remove the check for flags when performing unmap
      indirect desc

Xuan Zhuo (9):
  virtio_ring: rename vring_unmap_state_packed() to
    vring_unmap_extra_packed()
  virtio_ring: remove flags check for unmap split indirect desc
  virtio_ring: remove flags check for unmap packed indirect desc
  virtio_ring: virtqueue_add() support premapped
  virtio_ring: split: virtqueue_add_split() support premapped
  virtio_ring: packed: virtqueue_add_packed() support premapped
  virtio_ring: add api virtio_dma_map() for advance dma
  virtio_ring: introduce virtqueue_add_outbuf_premapped()
  virtio_net: xdp xmit use virtio dma api

 drivers/net/virtio_net.c     |  42 +++++-
 drivers/virtio/virtio_ring.c | 280 ++++++++++++++++++++++++++---------
 include/linux/virtio.h       |  12 ++
 3 files changed, 254 insertions(+), 80 deletions(-)

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2.31.0