Re: [PATCH v7 8/8] xen/arm: mmu: move MMU specific P2M code to mmu/p2m.{c,h}

[Julien Grall <julien@xxxxxxx>]

Hi Henry,

On 17/10/2023 06:55, Henry Wang wrote:
> > On Oct 14, 2023, at 02:22, Julien Grall <julien@xxxxxxx> wrote:
> >
> > Hi Henry,
> >
> > On 09/10/2023 02:03, Henry Wang wrote:
> > > diff --git a/xen/arch/arm/include/asm/p2m.h b/xen/arch/arm/include/asm/p2m.h
> > > index 940495d42b..a9622dac9a 100644
> > > --- a/xen/arch/arm/include/asm/p2m.h
> > > +++ b/xen/arch/arm/include/asm/p2m.h
> > > @@ -19,6 +19,22 @@ extern unsigned int p2m_root_level;
> > >   #define P2M_ROOT_ORDER    p2m_root_order
> > You seem to use P2M_ROOT_ORDER to allocate p2m->root in arm/p2m.c. However, as I 
> > mentioned before, I don't think the defintion of p2m->root is suitable for the MPU. I 
> > think the two functions using p2m->root should be moved in mmu/p2m.c and 
> > P2M_ROOT_ORDER should be moved in mmu/p2m.h.
> While working on this, I noticed that if we move p2m_final_teardown() (one of 
> the two
> functions you mentioned that consuming p2m->root), we also need to move the 
> static
> function p2m_free_vmid(). This seems reasonable as on MPU we only have dom0less
> domUs so we don’t really need to free vmid.
Regardless on whether you need to free VMID on MPU, the allocation and 
free functions should live in the same unit. So if you plan to move 
p2m_final_teardown() in mmu/p2m.c, then p2m_free_vmid should be exported.
Cheers,

--
Julien Grall