Re: [Qemu-devel] [PATCH 0/6] exec: Cleanup watchpoints

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

Ping for 5/6, as yet unreviewed.


r~

On 8/24/19 2:34 PM, Richard Henderson wrote:
> As discussed with David earlier this week, the current implementation
> of watchpoints cannot work, at least reliably.  We are raising an
> exception out of the middle of the i/o access path which does not
> even attempt to unwind the guest cpu state, nor does it have the
> information required to do so.
> 
> This moves the implementation to the cputlb helpers.  This is a point
> at which we can and do raise exceptions properly.
> 
> In addition, this fixes a bug in that unaligned stores were detecting
> watchpoints in the middle of the byte-by-byte operation, which means
> that we didn't signal the watchpoint early enough to avoid state change.
> 
> 
> r~
> 
> 
> David Hildenbrand (2):
>   exec: Factor out core logic of check_watchpoint()
>   tcg: Check for watchpoints in probe_write()
> 
> Richard Henderson (4):
>   exec: Move user-only watchpoint stubs inline
>   cputlb: Fold TLB_RECHECK into TLB_INVALID_MASK
>   exec: Factor out cpu_watchpoint_address_matches
>   cputlb: Handle watchpoints via TLB_WATCHPOINT
> 
>  include/exec/cpu-all.h |   8 +-
>  include/hw/core/cpu.h  |  37 +++++++++
>  accel/tcg/cputlb.c     | 156 ++++++++++++++++++++++++--------------
>  exec.c                 | 167 +++++++++--------------------------------
>  4 files changed, 173 insertions(+), 195 deletions(-)
>