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

Also regarding MMIO support for queue reset, I plan to support it after this
patch is passed.

Performing reset on a queue is divided into four steps:
     1. virtio_reset_vq()              - notify the device to reset the queue
     2. virtqueue_detach_unused_buf()  - recycle the buffer submitted
     3. virtqueue_reset_vring()        - reset the vring (may re-alloc)
     4. virtio_enable_resetq()         - mmap vring to device, and enable the queue

The first part 1-17 of this patch set implements virtio pci's support and API
for queue reset. The latter part is to make virtio-net support set_ringparam. Do
these things for this feature:

      1. virtio-net support rx,tx reset
      2. find_vqs() support to special the max size of each vq
      3. virtio-net support set_ringparam

#1 -#3 :       prepare
#4 -#12:       virtio ring support reset vring of the vq
#13-#14:       add helper
#15-#17:       virtio pci support reset queue and re-enable
#18-#21:       find_vqs() support sizes to special the max size of each vq
#23-#24:       virtio-net support rx, tx reset
#22, #25, #26: virtio-net support set ringparam

Please review. Thanks.

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 (26):
  virtio_pci: struct virtio_pci_common_cfg add queue_notify_data
  virtio: queue_reset: add VIRTIO_F_RING_RESET
  virtio: add helper virtqueue_get_vring_max_size()
  virtio_ring: split: extract the logic of creating vring
  virtio_ring: split: extract the logic of init vq and attach vring
  virtio_ring: packed: extrace the logic of creating vring
  virtio_ring: packed: extract the logic of init vq and attach vring
  virtio_ring: extract the logic of freeing vring
  virtio_ring: split: implement virtqueue_reset_vring_split()
  virtio_ring: packed: implement virtqueue_reset_vring_packed()
  virtio_ring: introduce virtqueue_reset_vring()
  virtio_ring: update the document of the virtqueue_detach_unused_buf
    for queue reset
  virtio: queue_reset: struct virtio_config_ops add callbacks for
    queue_reset
  virtio: add helper for queue reset
  virtio_pci: queue_reset: update struct virtio_pci_common_cfg and
    option functions
  virtio_pci: queue_reset: extract the logic of active vq for modern pci
  virtio_pci: queue_reset: 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: get ringparam by virtqueue_get_vring_max_size()
  virtio_net: split free_unused_bufs()
  virtio_net: support rx/tx queue reset
  virtio_net: set the default max ring size by find_vqs()
  virtio_net: support set_ringparam

 arch/um/drivers/virtio_uml.c             |   2 +-
 drivers/net/virtio_net.c                 | 257 ++++++++--
 drivers/platform/mellanox/mlxbf-tmfifo.c |   3 +-
 drivers/remoteproc/remoteproc_virtio.c   |   2 +-
 drivers/s390/virtio/virtio_ccw.c         |   2 +-
 drivers/virtio/virtio_mmio.c             |  12 +-
 drivers/virtio/virtio_pci_common.c       |  28 +-
 drivers/virtio/virtio_pci_common.h       |   3 +-
 drivers/virtio/virtio_pci_legacy.c       |   8 +-
 drivers/virtio/virtio_pci_modern.c       | 146 +++++-
 drivers/virtio/virtio_pci_modern_dev.c   |  36 ++
 drivers/virtio/virtio_ring.c             | 584 +++++++++++++++++------
 drivers/virtio/virtio_vdpa.c             |   2 +-
 include/linux/virtio.h                   |  12 +
 include/linux/virtio_config.h            |  74 ++-
 include/linux/virtio_pci_modern.h        |   2 +
 include/uapi/linux/virtio_config.h       |   7 +-
 include/uapi/linux/virtio_pci.h          |  14 +
 18 files changed, 979 insertions(+), 215 deletions(-)

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2.31.0