Re: [Qemu-devel] [RFC PATCH v1 4/4] target-arm: Compute page size based on ARM target cpu type

[Peter Maydell <peter.maydell@linaro.org>]

On 17 June 2016 at 11:20, Vijay Kilari <vijay.kilari@gmail.com> wrote:
> On Fri, Jun 17, 2016 at 1:12 AM, Richard Henderson <rth@twiddle.net> wrote:
>> On 06/14/2016 04:36 AM, Peter Maydell wrote:
>>> It would be better to delay the point at which we allocate
>>> the data structures which care about page size, rather than
>>> moving init of the CPU earlier.
>>
>> It would be *best* if we could re-initialize and re-allocate these data
>> structures so that we can follow the current page size as it changes.
>>
>> Yes, this might require flushing just about everything, but it's the kind of
>> thing that's likely to happen only at system startup.  After that, everything
>> benefits from having the correct (larger) page size.
>
> I tried shuffling the memory initialization code after cpu initialization.
> but it was full mess. So could not proceed further.
>
> However, I tried early creation cpu objects instead of doing it from
> machvirt_init.
> With this, initfn of the cpu model is called earlier and feature set is updated.
> With that I could fetch arm architecture info. Based on this we can
> choose page size.

This won't work, because machvirt_init needs to be able to specify
properties of the CPU. I think we need to solve the issues with
dynamically reinitializing and reallocating the data structures,
as rth suggests.

thanks
-- PMM