[Qemu-block] [RFC PATCH 0/5] atapi: change unlimited recursion to while loop

[Paolo Bonzini]

Real hardware doesn't have an unlimited stack, so the unlimited
recursion in the ATAPI code smells a bit.  In fact, the call to
ide_transfer_start easily becomes a tail call with a small change
to the code (patch 4).  The remaining four patches move code around
so as to the turn the call back to ide_atapi_cmd_reply_end into
another tail call, and then convert the (double) tail recursion into
a while loop.

I'm not sure how this can be tested, apart from adding a READ CD
test to ahci-test (which I don't really have time for now, hence
the RFC tag).  The existing AHCI tests still pass, so patches 1-3
aren't complete crap.

Paolo

Paolo Bonzini (5):
  ide: push call to end_transfer_func out of start_transfer callback
  ide: push end_transfer callback to ide_transfer_halt
  ide: make ide_transfer_stop idempotent
  atapi: call ide_set_irq before ide_transfer_start
  ide: introduce ide_transfer_start_norecurse

 hw/ide/ahci.c             | 12 +++++++-----
 hw/ide/atapi.c            | 37 ++++++++++++++++++++-----------------
 hw/ide/core.c             | 37 +++++++++++++++++++++++--------------
 include/hw/ide/internal.h |  3 +++
 4 files changed, 53 insertions(+), 36 deletions(-)

-- 
2.14.3