virtio pci support VIRTIO_F_RING_RESET

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/89f3bfa3265554d1...

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.

v13:
  1. virtqueue attached by vq->split = *vring_split / vq->packed = *vring_packed
  2. call __virtqueue_break() unconditionally

v12:
  1. access vq->num_max directly without helper
  2. rename the vq reset callbacks:
 	     int (*disable_vq_and_reset)(struct virtqueue *vq);
 	     int (*enable_vq_after_reset)(struct virtqueue *vq);

  3. rename vring to vring_split, vring_packed
  4. protect sq->reset by tx lock

v11:
  1. struct virtio_pci_common_cfg to virtio_pci_modern.h
  2. conflict resolution

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

Xuan Zhuo (42):
  virtio: record the maximum queue num supported by the device.
  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: extract the logic of freeing vring
  virtio_ring: split vring_virtqueue
  virtio_ring: introduce virtqueue_init()
  virtio_ring: split: stop __vring_new_virtqueue as export symbol
  virtio_ring: split: __vring_new_virtqueue() accept struct
    vring_virtqueue_split
  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 vring init
  virtio_ring: split: extract the logic of attach vring
  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 vring init
  virtio_ring: packed: extract the logic of attach vring
  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: allow to unbreak/break virtqueue individually
  virtio: queue_reset: add VIRTIO_F_RING_RESET
  virtio_ring: struct virtqueue introduce reset
  virtio_pci: struct virtio_pci_common_cfg add queue_reset
  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                 | 208 +++++-
 drivers/platform/mellanox/mlxbf-tmfifo.c |   3 +
 drivers/remoteproc/remoteproc_virtio.c   |   3 +
 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       | 153 ++++-
 drivers/virtio/virtio_pci_modern_dev.c   |  39 ++
 drivers/virtio/virtio_ring.c             | 786 ++++++++++++++++-------
 drivers/virtio/virtio_vdpa.c             |   3 +
 include/linux/virtio.h                   |  10 +
 include/linux/virtio_config.h            |  40 +-
 include/linux/virtio_pci_modern.h        |   9 +
 include/linux/virtio_ring.h              |  10 -
 include/uapi/linux/virtio_config.h       |   7 +-
 include/uapi/linux/virtio_pci.h          |   2 +
 tools/virtio/virtio_test.c               |   4 +-
 20 files changed, 1037 insertions(+), 301 deletions(-)

--
2.31.0