On Wed, 30 Mar 2022 06:51:03 -0400, "Michael S. Tsirkin" <mst at
redhat.com> wrote:> On Wed, Mar 30, 2022 at 05:03:32PM +0800, Xuan Zhuo wrote:
> > On Wed, 30 Mar 2022 16:38:18 +0800, Jason Wang <jasowang at
redhat.com> wrote:
> > > On Wed, Mar 30, 2022 at 2:59 PM Xuan Zhuo <xuanzhuo at
linux.alibaba.com> wrote:
> > > >
> > > > On Wed, 30 Mar 2022 14:56:17 +0800, Jason Wang <jasowang
at redhat.com> wrote:
> > > > > On Wed, Mar 30, 2022 at 2:34 PM Michael S. Tsirkin
<mst at redhat.com> wrote:
> > > > > >
> > > > > > On Thu, Feb 24, 2022 at 07:03:53PM +0800, Xuan
Zhuo wrote:
> > > > > > > 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
> ?
#1 resize with drop unused bufs directly
#2 premapped and resize support reuse the unused bufs
This way "premaped" will have a user.
Between #1 and #2, I may submit some code with optimized formatting, because
jason doesn't like my introduction of struct vring_split and struct
vring_packed
in #1 for passing parameters between extracted functions.
Thanks.
>
>
>
> >
> > >
> > > Thanks
> > >
> > > >
> > > > Thanks.
> > > >
> > > >
> > > > >
> > > > > Thanks
> > > > >
> > > > > >
> > > > > > Thanks!
> > > > > >
> > > > > > > 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(-)
> > > > > > >
> > > > > > > --
> > > > > > > 2.31.0
> > > > > >
> > > > >
> > > >
> > >
>