Re: [Qemu-devel] [PATCH v6 05/14] target/arm: Reorganize PMCCNTR accesses

[Aaron Lindsay]

On Oct 15 12:50, Richard Henderson wrote:
> On 10/10/18 1:37 PM, Aaron Lindsay wrote:
> > pmccntr_read and pmccntr_write contained duplicate code that was already
> > being handled by pmccntr_sync. Consolidate the duplicated code into two
> > functions: pmccntr_op_start and pmccntr_op_finish. Add a companion to
> > c15_ccnt in CPUARMState so that we can simultaneously save both the
> > architectural register value and the last underlying cycle count - this
> > ensures time isn't lost and will also allow us to access the 'old'
> > architectural register value in order to detect overflows in later
> > patches.
> > 
> > Signed-off-by: Aaron Lindsay <address@hidden>
> > ---
> >  target/arm/cpu.h     | 26 ++++++++----
> >  target/arm/helper.c  | 96 +++++++++++++++++++++++---------------------
> >  target/arm/machine.c |  8 ++--
> >  3 files changed, 73 insertions(+), 57 deletions(-)
> 
> Ok, looking at this follow-up makes more sense than the previous patch.  Would
> it make sense to squash these two together?

I was attempting to keep the migration plumbing separate from the PMU
implementation details, but I'm not particularly partial to this
staging.

> It also makes sense why you'd need the post_save hook.

Okay. I attempted to describe this in the commit message in a way that
communicated the need for the hook without being overly verbose - but
suggestions in that area are very welcome if you think a different
commit message would help.

-Aaron