Re: [Qemu-devel] [PATCH for-1.4 0/2] target-s390x: CPU cleanups preparing for 1.5

[Alexander Graf]

On 31.01.2013, at 17:15, Andreas Färber wrote:

> Am 31.01.2013 16:48, schrieb Alexander Graf:
>> 
>> On 31.01.2013, at 16:23, Andreas Färber wrote:
>> 
>>> Am 30.01.2013 23:48, schrieb Andreas Färber:
>>>> As a reminder here's a link to one of my original discussions of the new 
>>>> types:
>>>> https://lists.nongnu.org/archive/html/qemu-devel/2012-05/msg01286.html
>>>> 
>>>> That is, for any non-TCG functions (TCG does not support CPUState yet) an
>>>> S390CPU argument should be preferred over CPUS390XState since it allows 
>>>> cheap
>>>> access to its own fields, CPUState's via CPU() and to CPUS390XState via 
>>>> ->env.
>>>> Doing this consistently avoids costs of casting back and forth 
>>>> unnecessarily.
>>>> 
>>>> s390 code should use s390_env_get_cpu() where needed, not ENV_GET_CPU().
>>>> 
>>>> As a rule of thumb, any field in include/exec/cpu-defs.h:CPU_COMMON can be
>>>> expected to end up in CPUState (or accessible from there) sooner or later.
>>> 
>>>> Per-target functions can be expected to change to CPUState soon.
>>> 
>>> Maybe too brief: This was referring to functions like kvm_arch_*() that
>>> each target implements, knowing its CPU type. In particular
>>> do_interrupt() is one of my next candidates.
>> 
>> Any particular reason this is 1.4 material?
> 
> 1/2 is the cleanup of 1.4's virtio-ccw that we discussed at IBM.
> 2/2 shows that variable placement inside do_interrupt() was no accident.
> 
> The alternative is you acking it and me putting it in qom-cpu-next.
> It's a prereq for other series as indicated in the commit messages and
> we're not in Hard Freeze yet, so you get to decide.

Well, I'd hope having it in now makes backporting patches later easier, so I 
just applied them.

Thanks a lot for all your refactoring work :)


Alex