Re: [PATCH RFC V3 24/29] target/arm: Add support of *unrealize* ARMCPU during vCPU Hot-unplug

[Peter Maydell]

On Mon, 19 Aug 2024 at 13:59, Salil Mehta <salil.mehta@huawei.com> wrote:
>
> >  From: Peter Maydell <peter.maydell@linaro.org>
> >  Sent: Friday, August 16, 2024 6:00 PM
> >  To: Alex Bennée <alex.bennee@linaro.org>
> >
> >  On Fri, 16 Aug 2024 at 16:50, Peter Maydell <peter.maydell@linaro.org>
> >  wrote:
> >  > We shouldn't need to explicitly call cpu_address_space_destroy() from
> >  > a target-specific unrealize anyway: we can do it all from the base
> >  > class (and I think this would fix some leaks in current code for
> >  > targets that hot-unplug, though I should check that). Otherwise you
> >  > need to duplicate all the logic for figuring out which address spaces
> >  > we created in realize, which is fragile and not necessary when all we
> >  > want to do is "delete every address space the CPU object has"
> >  > and we want to do that for every target architecture always.
> >
> >  I have a patch to do this now, but I need to test it a bit more and 
> > confirm (or
> >  disprove) my hypothesis that we're currently leaking memory on existing
> >  architectures with vCPU hot-unplug before I send it out.
>
> I think you are referring to this patch?
>
> https://lore.kernel.org/qemu-devel/20230918160257.30127-9-philmd@linaro.org/

I'd forgotten that Phil had sent that patch out. My patch
is a bit different because it refactors cpu_address_space_destroy()
into a single function that destroys all the ASes (and so we
don't for instance need cpu->cpu_ases_count any more).

-- PMM