Subject: Re: [PATCH v10 00/41] virtio pci support VIRTIO_F_RING_RESET

From: "Michael S. Tsirkin" <[email-masked]>
Date: Fri, 24 Jun 2022 03:00:12 -0400

On Fri, Jun 24, 2022 at 10:55:40AM +0800, Xuan Zhuo 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
>     https://github.com/oasis-tcs/virtio-spec/issues/139
> 
> Also regarding MMIO support for queue reset, I plan to support it after this
> patch is passed.
> 
> This patch set implements the refactoring of vring. Finally, the
> virtuque_resize() interface is provided based on the reset function of the
> transport layer.
> 
> Test environment:
>     Host: 4.19.91
>     Qemu: QEMU emulator version 6.2.50 (with vq reset support)
>     Test Cmd:  ethtool -G eth1 rx $1 tx $2; ethtool -g eth1
> 
>     The default is split mode, modify Qemu virtio-net to add PACKED feature to test
>     packed mode.
> 
> Qemu code:
>     https://github.com/fengidri/qemu/compare/89f3bfa3265554d1d591ee4d7f1197b6e3397e84...master

Pls rebase on top of my latest tree, there are some conflicts.

> In order to simplify the review of this patch set, the function of reusing
> the old buffers after resize will be introduced in subsequent patch sets.
> 
> Please review. Thanks.
> 
> v10:
>   1. on top of the harden vring IRQ
>   2. factor out split and packed from struct vring_virtqueue
>   3. some suggest from @Jason Wang
> 
> v9:
>   1. Provide a virtqueue_resize() interface directly
>   2. A patch set including vring resize, virtio pci reset, virtio-net resize
>   3. No more separate structs
> 
> v8:
>   1. Provide a virtqueue_reset() interface directly
>   2. Split the two patch sets, this is the first part
>   3. Add independent allocation helper for allocating state, extra
> 
> v7:
>   1. fix #6 subject typo
>   2. fix #6 ring_size_in_bytes is uninitialized
>   3. check by: make W=12
> 
> v6:
>   1. virtio_pci: use synchronize_irq(irq) to sync the irq callbacks
>   2. Introduce virtqueue_reset_vring() to implement the reset of vring during
>      the reset process. May use the old vring if num of the vq not change.
>   3. find_vqs() support sizes to special the max size of each vq
> 
> v5:
>   1. add virtio-net support set_ringparam
> 
> 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
> 
> *** BLURB HERE ***
> 
> Xuan Zhuo (41):
>   remoteproc: rename len of rpoc_vring to num
>   virtio: add helper virtqueue_get_vring_max_size()
>   virtio: struct virtio_config_ops add callbacks for queue_reset
>   virtio_ring: update the document of the virtqueue_detach_unused_buf
>     for queue reset
>   virtio_ring: remove the arg vq of vring_alloc_desc_extra()
>   virtio_ring: extract the logic of freeing vring
>   virtio_ring: split vring_virtqueue
>   virtio_ring: introduce virtqueue_init()
>   virtio_ring: split: introduce vring_free_split()
>   virtio_ring: split: extract the logic of alloc queue
>   virtio_ring: split: extract the logic of alloc state and extra
>   virtio_ring: split: extract the logic of attach vring
>   virtio_ring: split: extract the logic of vring init
>   virtio_ring: split: introduce virtqueue_reinit_split()
>   virtio_ring: split: reserve vring_align, may_reduce_num
>   virtio_ring: split: introduce virtqueue_resize_split()
>   virtio_ring: packed: introduce vring_free_packed
>   virtio_ring: packed: extract the logic of alloc queue
>   virtio_ring: packed: extract the logic of alloc state and extra
>   virtio_ring: packed: extract the logic of attach vring
>   virtio_ring: packed: extract the logic of vring init
>   virtio_ring: packed: introduce virtqueue_reinit_packed()
>   virtio_ring: packed: introduce virtqueue_resize_packed()
>   virtio_ring: introduce virtqueue_resize()
>   virtio_pci: struct virtio_pci_common_cfg add queue_notify_data
>   virtio: queue_reset: add VIRTIO_F_RING_RESET
>   virtio: allow to unbreak/break virtqueue individually
>   virtio_pci: update struct virtio_pci_common_cfg
>   virtio_pci: introduce helper to get/set queue reset
>   virtio_pci: extract the logic of active vq for modern pci
>   virtio_pci: support VIRTIO_F_RING_RESET
>   virtio: find_vqs() add arg sizes
>   virtio_pci: support the arg sizes of find_vqs()
>   virtio_mmio: support the arg sizes of find_vqs()
>   virtio: add helper virtio_find_vqs_ctx_size()
>   virtio_net: set the default max ring size by find_vqs()
>   virtio_net: get ringparam by virtqueue_get_vring_max_size()
>   virtio_net: split free_unused_bufs()
>   virtio_net: support rx queue resize
>   virtio_net: support tx queue resize
>   virtio_net: support set_ringparam
> 
>  arch/um/drivers/virtio_uml.c             |   3 +-
>  drivers/net/virtio_net.c                 | 209 +++++-
>  drivers/platform/mellanox/mlxbf-tmfifo.c |   3 +
>  drivers/remoteproc/remoteproc_core.c     |   4 +-
>  drivers/remoteproc/remoteproc_virtio.c   |  13 +-
>  drivers/s390/virtio/virtio_ccw.c         |   4 +
>  drivers/virtio/virtio_mmio.c             |  11 +-
>  drivers/virtio/virtio_pci_common.c       |  32 +-
>  drivers/virtio/virtio_pci_common.h       |   3 +-
>  drivers/virtio/virtio_pci_legacy.c       |   8 +-
>  drivers/virtio/virtio_pci_modern.c       | 157 ++++-
>  drivers/virtio/virtio_pci_modern_dev.c   |  39 ++
>  drivers/virtio/virtio_ring.c             | 794 +++++++++++++++++------
>  drivers/virtio/virtio_vdpa.c             |   3 +
>  include/linux/remoteproc.h               |   4 +-
>  include/linux/virtio.h                   |   9 +
>  include/linux/virtio_config.h            |  38 +-
>  include/linux/virtio_pci_modern.h        |   2 +
>  include/uapi/linux/virtio_config.h       |   7 +-
>  include/uapi/linux/virtio_pci.h          |  14 +
>  20 files changed, 1063 insertions(+), 294 deletions(-)
> 
> --
> 2.31.0