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[vhost,00/17] virtio: drivers maintain dma info for premapped vq

Message ID 20240130114224.86536-1-xuanzhuo@linux.alibaba.com (mailing list archive)
Headers show
Series virtio: drivers maintain dma info for premapped vq | expand

Message

Xuan Zhuo Jan. 30, 2024, 11:42 a.m. UTC
As discussed:
http://lore.kernel.org/all/CACGkMEvq0No8QGC46U4mGsMtuD44fD_cfLcPaVmJ3rHYqRZxYg@mail.gmail.com

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.
So we can release the memory used to store the dma info.

But if the desc_extra has not dma info, we face a new question,
it is hard to get the dma info of the desc with indirect flag.
For split mode, that is easy from desc, but for the packed mode,
it is hard to get the dma info from the desc. And for hardening
the dma unmap is saft, we should store the dma info of indirect
descs.

So I introduce the "structure the indirect desc table" to
allocate space to store dma info with the desc table.

On the other side, we mix the descs with indirect flag
with other descs together to share the unmap api. That
is complex. I found if we we distinguish the descs with
VRING_DESC_F_INDIRECT before unmap, thing will be clearer.

Because of the dma array is allocated in the find_vqs(),
so I introduce a new parameter to find_vqs().

Please review.

Thanks

Xuan Zhuo (17):
  virtio_ring: introduce vring_need_unmap_buffer
  virtio_ring: packed: remove double check of the unmap ops
  virtio_ring: packed: structure the indirect desc table
  virtio_ring: split: remove double check of the unmap ops
  virtio_ring: split: structure the indirect desc table
  virtio_ring: no store dma info when unmap is not needed
  virtio: find_vqs: pass struct instead of multi parameters
  virtio: vring_new_virtqueue(): pass struct instead of multi parameters
  virtio_ring: reuse the parameter struct of find_vqs()
  virtio: find_vqs: add new parameter premapped
  virtio_ring: export premapped to driver by struct virtqueue
  virtio_net: set premapped mode by find_vqs()
  virtio_ring: remove api of setting vq premapped
  virtio_ring: introduce dma map api for page
  virtio_net: unify the code for recycling the xmit ptr
  virtio_net: rename free_old_xmit_skbs to free_old_xmit
  virtio_net: sq support premapped mode

 arch/um/drivers/virtio_uml.c             |  29 +-
 drivers/net/virtio_net.c                 | 298 +++++++---
 drivers/platform/mellanox/mlxbf-tmfifo.c |  24 +-
 drivers/remoteproc/remoteproc_virtio.c   |  31 +-
 drivers/s390/virtio/virtio_ccw.c         |  33 +-
 drivers/virtio/virtio_mmio.c             |  30 +-
 drivers/virtio/virtio_pci_common.c       |  59 +-
 drivers/virtio/virtio_pci_common.h       |   9 +-
 drivers/virtio/virtio_pci_legacy.c       |  16 +-
 drivers/virtio/virtio_pci_modern.c       |  24 +-
 drivers/virtio/virtio_ring.c             | 660 ++++++++++++-----------
 drivers/virtio/virtio_vdpa.c             |  33 +-
 include/linux/virtio.h                   |  10 +-
 include/linux/virtio_config.h            |  48 +-
 include/linux/virtio_ring.h              |  82 +--
 tools/virtio/virtio_test.c               |   4 +-
 tools/virtio/vringh_test.c               |  32 +-
 17 files changed, 812 insertions(+), 610 deletions(-)

--
2.32.0.3.g01195cf9f

Comments

Zhu Yanjun Feb. 1, 2024, 7:43 a.m. UTC | #1
在 2024/1/30 19:42, Xuan Zhuo 写道:
> As discussed:
> http://lore.kernel.org/all/CACGkMEvq0No8QGC46U4mGsMtuD44fD_cfLcPaVmJ3rHYqRZxYg@mail.gmail.com
> 
> 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.
> So we can release the memory used to store the dma info.
> 
> But if the desc_extra has not dma info, we face a new question,
> it is hard to get the dma info of the desc with indirect flag.
> For split mode, that is easy from desc, but for the packed mode,
> it is hard to get the dma info from the desc. And for hardening
> the dma unmap is saft, we should store the dma info of indirect
> descs.
> 
> So I introduce the "structure the indirect desc table" to
> allocate space to store dma info with the desc table.
> 
> On the other side, we mix the descs with indirect flag
> with other descs together to share the unmap api. That
> is complex. I found if we we distinguish the descs with
> VRING_DESC_F_INDIRECT before unmap, thing will be clearer.
> 
> Because of the dma array is allocated in the find_vqs(),
> so I introduce a new parameter to find_vqs().
> 
> Please review.
> 
> Thanks
> 
> Xuan Zhuo (17):
>    virtio_ring: introduce vring_need_unmap_buffer
>    virtio_ring: packed: remove double check of the unmap ops
>    virtio_ring: packed: structure the indirect desc table
>    virtio_ring: split: remove double check of the unmap ops
>    virtio_ring: split: structure the indirect desc table
>    virtio_ring: no store dma info when unmap is not needed
>    virtio: find_vqs: pass struct instead of multi parameters
>    virtio: vring_new_virtqueue(): pass struct instead of multi parameters
>    virtio_ring: reuse the parameter struct of find_vqs()
>    virtio: find_vqs: add new parameter premapped
>    virtio_ring: export premapped to driver by struct virtqueue
>    virtio_net: set premapped mode by find_vqs()
>    virtio_ring: remove api of setting vq premapped
>    virtio_ring: introduce dma map api for page
>    virtio_net: unify the code for recycling the xmit ptr
>    virtio_net: rename free_old_xmit_skbs to free_old_xmit
>    virtio_net: sq support premapped mode

The above can not be cleanly merged into kernel 6.8-rc2.

Perhaps a base-commit is needed. About base-commit, please see the link
https://people.kernel.org/monsieuricon/all-patches-must-include-base-commit-info

Zhu Yanjun

> 
>   arch/um/drivers/virtio_uml.c             |  29 +-
>   drivers/net/virtio_net.c                 | 298 +++++++---
>   drivers/platform/mellanox/mlxbf-tmfifo.c |  24 +-
>   drivers/remoteproc/remoteproc_virtio.c   |  31 +-
>   drivers/s390/virtio/virtio_ccw.c         |  33 +-
>   drivers/virtio/virtio_mmio.c             |  30 +-
>   drivers/virtio/virtio_pci_common.c       |  59 +-
>   drivers/virtio/virtio_pci_common.h       |   9 +-
>   drivers/virtio/virtio_pci_legacy.c       |  16 +-
>   drivers/virtio/virtio_pci_modern.c       |  24 +-
>   drivers/virtio/virtio_ring.c             | 660 ++++++++++++-----------
>   drivers/virtio/virtio_vdpa.c             |  33 +-
>   include/linux/virtio.h                   |  10 +-
>   include/linux/virtio_config.h            |  48 +-
>   include/linux/virtio_ring.h              |  82 +--
>   tools/virtio/virtio_test.c               |   4 +-
>   tools/virtio/vringh_test.c               |  32 +-
>   17 files changed, 812 insertions(+), 610 deletions(-)
> 
> --
> 2.32.0.3.g01195cf9f
>
Xuan Zhuo Feb. 1, 2024, 9:57 a.m. UTC | #2
On Thu, 1 Feb 2024 15:43:51 +0800, Zhu Yanjun <yanjun.zhu@linux.dev> wrote:
> 在 2024/1/30 19:42, Xuan Zhuo 写道:
> > As discussed:
> > http://lore.kernel.org/all/CACGkMEvq0No8QGC46U4mGsMtuD44fD_cfLcPaVmJ3rHYqRZxYg@mail.gmail.com
> >
> > 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.
> > So we can release the memory used to store the dma info.
> >
> > But if the desc_extra has not dma info, we face a new question,
> > it is hard to get the dma info of the desc with indirect flag.
> > For split mode, that is easy from desc, but for the packed mode,
> > it is hard to get the dma info from the desc. And for hardening
> > the dma unmap is saft, we should store the dma info of indirect
> > descs.
> >
> > So I introduce the "structure the indirect desc table" to
> > allocate space to store dma info with the desc table.
> >
> > On the other side, we mix the descs with indirect flag
> > with other descs together to share the unmap api. That
> > is complex. I found if we we distinguish the descs with
> > VRING_DESC_F_INDIRECT before unmap, thing will be clearer.
> >
> > Because of the dma array is allocated in the find_vqs(),
> > so I introduce a new parameter to find_vqs().
> >
> > Please review.
> >
> > Thanks
> >
> > Xuan Zhuo (17):
> >    virtio_ring: introduce vring_need_unmap_buffer
> >    virtio_ring: packed: remove double check of the unmap ops
> >    virtio_ring: packed: structure the indirect desc table
> >    virtio_ring: split: remove double check of the unmap ops
> >    virtio_ring: split: structure the indirect desc table
> >    virtio_ring: no store dma info when unmap is not needed
> >    virtio: find_vqs: pass struct instead of multi parameters
> >    virtio: vring_new_virtqueue(): pass struct instead of multi parameters
> >    virtio_ring: reuse the parameter struct of find_vqs()
> >    virtio: find_vqs: add new parameter premapped
> >    virtio_ring: export premapped to driver by struct virtqueue
> >    virtio_net: set premapped mode by find_vqs()
> >    virtio_ring: remove api of setting vq premapped
> >    virtio_ring: introduce dma map api for page
> >    virtio_net: unify the code for recycling the xmit ptr
> >    virtio_net: rename free_old_xmit_skbs to free_old_xmit
> >    virtio_net: sq support premapped mode
>
> The above can not be cleanly merged into kernel 6.8-rc2.
>
> Perhaps a base-commit is needed. About base-commit, please see the link
> https://people.kernel.org/monsieuricon/all-patches-must-include-base-commit-info

The target branch is Michael's vhost.

https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git/log/?h=linux-next

Thanks.

>
> Zhu Yanjun
>
> >
> >   arch/um/drivers/virtio_uml.c             |  29 +-
> >   drivers/net/virtio_net.c                 | 298 +++++++---
> >   drivers/platform/mellanox/mlxbf-tmfifo.c |  24 +-
> >   drivers/remoteproc/remoteproc_virtio.c   |  31 +-
> >   drivers/s390/virtio/virtio_ccw.c         |  33 +-
> >   drivers/virtio/virtio_mmio.c             |  30 +-
> >   drivers/virtio/virtio_pci_common.c       |  59 +-
> >   drivers/virtio/virtio_pci_common.h       |   9 +-
> >   drivers/virtio/virtio_pci_legacy.c       |  16 +-
> >   drivers/virtio/virtio_pci_modern.c       |  24 +-
> >   drivers/virtio/virtio_ring.c             | 660 ++++++++++++-----------
> >   drivers/virtio/virtio_vdpa.c             |  33 +-
> >   include/linux/virtio.h                   |  10 +-
> >   include/linux/virtio_config.h            |  48 +-
> >   include/linux/virtio_ring.h              |  82 +--
> >   tools/virtio/virtio_test.c               |   4 +-
> >   tools/virtio/vringh_test.c               |  32 +-
> >   17 files changed, 812 insertions(+), 610 deletions(-)
> >
> > --
> > 2.32.0.3.g01195cf9f
> >
>