Re: [PATCH] target/mips: Fix PageMask with variable page size

[Jiaxun Yang]

在 2020/6/15 17:13, Peter Maydell 写道:
> On Sun, 14 Jun 2020 at 22:52, Aleksandar Markovic
> <aleksandar.qemu.devel@gmail.com> wrote:
> > When you change machine.c the way you did it, you need to bump the version. 
> > Please see git log on machine.c for details.
>
> > > --- a/target/mips/cpu.h
> > > +++ b/target/mips/cpu.h
> > > @@ -617,7 +617,8 @@ struct CPUMIPSState {
> > >   /*
> > >    * CP0 Register 5
> > >    */
> > > -    int32_t CP0_PageMask;
> > > +    target_ulong CP0_PageMask;
> > > +#define CP0PM_MASK 13
>
> Does CP0_PageMask ever actually hold a value that won't fit
> in an int32_t? If not, it might be preferable to avoid changing
> its type to avoid the migration compat break, even if MIPS
> doesn't have any versioned boards where we have a strict
> don't-break-compat promise to users.

In Release2, PageMask was extended to 64bit on MIPS64 processors.

Is it necessary to follow that?

Thanks.

> thanks
> -- PMM

--
- Jiaxun