On Fri, 11 Feb 2022 13:40:52 +0800, Jason Wang <jasowang at redhat.com>
wrote:> On Wed, Feb 9, 2022 at 8:29 PM Xuan Zhuo <xuanzhuo at
linux.alibaba.com> wrote:
> >
> > The virtio spec already supports the virtio queue reset function. This
patch set
> > is to add this function to the kernel. The relevant virtio spec
information is
> > here:
> >
> > https://github.com/oasis-tcs/virtio-spec/issues/124
> >
> > Also regarding MMIO support for queue reset, I plan to support it
after this
> > patch is passed.
>
> So I had an idea, we can implement ethtool_set_ringparam() in this
> series to get one real users.
I agree, in fact my local test is using this feature.
>
> But this came into another question: it looks to me current virito-net
> just uses the maximum ring size, so it basically means we just can
> decrease the number from startup, so I wonder how much value if we
> don't limit the startup queue size to a dedicated value.
I also have this consideration, so I want to add a virtio-net module parameter
to specify an initial value.
This initial value also has another meaning. In order to achieve high
performance, the backend can provide a large ring size capability, but we also
hope that the ring size can only be increased through ethtool -G when the user
needs it.
To implement this function, we need to add a new parameter to find_vqs().
If there is no problem, I will bring this function in the next version.
Thannks.
>
> Thanks
>
> >
> > Please review. Thanks.
> >
> > v4:
> > 1. just the code of virtio, without virtio-net
> > 2. Performing reset on a queue is divided into these steps:
> > 1. reset_vq: reset one vq
> > 2. recycle the buffer from vq by virtqueue_detach_unused_buf()
> > 3. release the ring of the vq by vring_release_virtqueue()
> > 4. enable_reset_vq: re-enable the reset queue
> > 3. Simplify the parameters of enable_reset_vq()
> > 4. add container structures for virtio_pci_common_cfg
> >
> > v3:
> > 1. keep vq, irq unreleased
> >
> > Xuan Zhuo (14):
> > virtio_pci: struct virtio_pci_common_cfg add queue_notify_data
> > virtio: queue_reset: add VIRTIO_F_RING_RESET
> > virtio_ring: queue_reset: add function vring_setup_virtqueue()
> > virtio_ring: queue_reset: split: add __vring_init_virtqueue()
> > virtio_ring: queue_reset: split: support enable reset queue
> > virtio_ring: queue_reset: packed: support enable reset queue
> > virtio_ring: queue_reset: extract the release function of the vq
ring
> > virtio_ring: queue_reset: add vring_release_virtqueue()
> > virtio: queue_reset: struct virtio_config_ops add callbacks for
> > queue_reset
> > virtio_pci: queue_reset: update struct virtio_pci_common_cfg and
> > option functions
> > virtio_pci: queue_reset: release vq by vp_dev->vqs
> > virtio_pci: queue_reset: setup_vq() support vring_setup_virtqueue()
> > virtio_pci: queue_reset: vp_setup_vq() support ring_num
> > virtio_pci: queue_reset: support VIRTIO_F_RING_RESET
> >
> > drivers/virtio/virtio_pci_common.c | 65 +++++++---
> > drivers/virtio/virtio_pci_common.h | 11 +-
> > drivers/virtio/virtio_pci_legacy.c | 5 +-
> > drivers/virtio/virtio_pci_modern.c | 99 ++++++++++++--
> > drivers/virtio/virtio_pci_modern_dev.c | 36 +++++
> > drivers/virtio/virtio_ring.c | 173
++++++++++++++++++-------
> > include/linux/virtio.h | 6 +
> > include/linux/virtio_config.h | 13 ++
> > include/linux/virtio_pci_modern.h | 2 +
> > include/linux/virtio_ring.h | 37 ++++--
> > include/uapi/linux/virtio_config.h | 7 +-
> > include/uapi/linux/virtio_pci.h | 14 ++
> > 12 files changed, 375 insertions(+), 93 deletions(-)
> >
> > --
> > 2.31.0
> >
>