[Qemu-devel] [RFC v2 0/5] Move notdirty handling to cputlb

[Richard Henderson <richard.henderson@linaro.org>]

RFC because it *still* doesn't work, just like v1.

However this time the changes are extremely minimal, and now
I really *really* don't understand why they don't work, because
as far as I can tell the new locking is *identical* with the
current i/o path.

In particular, the actual access happens between _prepare
and _complete, just like before.  Indeed, since this doesn't
work as-is, then I can't believe the atomic path works either.

I have included the TLB_BSWAP stuff just so that the
patch set is self-contained.

I did experiment with qemu_ram_addr_from_host_nofail(), but
an assertion for equality with addr + iotlbentry->addr does
not trigger.  As expected, really, since that's what the i/o
path uses.  One more cleanup for the atomics path...

Ideas?


r~


Richard Henderson (5):
  cputlb: Disable __always_inline__ without optimization
  cputlb: Replace switches in load/store_helper with callback
  cputlb: Introduce TLB_BSWAP
  exec: Adjust notdirty tracing
  cputlb: Move NOTDIRTY handling from I/O path to TLB path

 include/exec/cpu-all.h    |   2 +
 include/exec/cpu-common.h |   1 -
 include/qemu/compiler.h   |  11 ++
 accel/tcg/cputlb.c        | 243 +++++++++++++++++++++-----------------
 exec.c                    |  57 +--------
 memory.c                  |  20 ----
 trace-events              |   4 +-
 7 files changed, 157 insertions(+), 181 deletions(-)

-- 
2.17.1