[0/7] Supoort shared irq for virtqueues

Message

Zhu, Lingshan Jan. 10, 2022, 5:19 a.m. UTC

On some platforms, it has been observed that a device may fail to
allocate enough MSI-X vectors, under such circumstances, the vqs have
to share a irq/vector.

This series extends irq requester/handlers abilities to deal with:
(granted nvectors, and max_intr = total vq number + 1(config interrupt) )

1)nvectors = max_intr: each vq has its own vector/irq,
config interrupt is enabled, normal case
2)max_intr > nvectors >= 2: vqs share one irq/vector, config interrupt is
enabled
3)nvectors = 1, vqs share one irq/vector, config interrupt is disabled.
Otherwise it fails.

This series also made necessary changes to irq cleaners and related
helpers.

Pleaase help reivew.

Thanks!
Zhu Lingshan

Zhu Lingshan (7):
  vDPA/ifcvf: implement IO read/write helpers in the header file
  vDPA/ifcvf: introduce new helpers to set config vector and vq vectors
  vDPA/ifcvf: implement device MSIX vector allocation helper
  vDPA/ifcvf: implement shared irq handlers for vqs
  vDPA/ifcvf: irq request helpers for both shared and per_vq irq
  vDPA/ifcvf: implement config interrupt request helper
  vDPA/ifcvf: improve irq requester, to handle per_vq/shared/config irq

 drivers/vdpa/ifcvf/ifcvf_base.c |  65 ++++--------
 drivers/vdpa/ifcvf/ifcvf_base.h |  45 +++++++-
 drivers/vdpa/ifcvf/ifcvf_main.c | 179 +++++++++++++++++++++++++++-----
 3 files changed, 215 insertions(+), 74 deletions(-)