Re: [PATCH 3/3] [DO NOT COMMIT] xen/arm: Create a trampoline for secondary boot CPUs

[Julien Grall <julien@xxxxxxx>]

On 16/01/2024 14:24, Carlo Nonato wrote:
> Hi Julien,
>
> On Tue, Jan 16, 2024 at 12:55 PM Julien Grall <julien@xxxxxxx> wrote:
> > From: Julien Grall <jgrall@xxxxxxxxxx>
> >
> > In order to confirm the early boot code is self-contained, allocate a
> > separate trampoline region for secondary to boot from it.
> >
> > Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
> > ---
> >   xen/arch/arm/arm64/mmu/mm.c |  7 +++++++
> >   xen/arch/arm/mmu/smpboot.c  |  4 +++-
> >   xen/arch/arm/psci.c         |  5 ++++-
> >   xen/arch/arm/smpboot.c      | 15 ++++++++++++++-
> >   4 files changed, 28 insertions(+), 3 deletions(-)
> >
> > diff --git a/xen/arch/arm/arm64/mmu/mm.c b/xen/arch/arm/arm64/mmu/mm.c
> > index d2651c948698..3c4988dc75d1 100644
> > --- a/xen/arch/arm/arm64/mmu/mm.c
> > +++ b/xen/arch/arm/arm64/mmu/mm.c
> > @@ -110,11 +110,18 @@ void __init arch_setup_page_tables(void)
> >       prepare_runtime_identity_mapping();
> >   }
> >
> > +extern mfn_t trampoline_start;
> > +
> >   void update_identity_mapping(bool enable)
> >   {
> >       paddr_t id_addr = virt_to_maddr(_start);
> >       int rc;
> >
> > +    if ( !mfn_eq(trampoline_start, INVALID_MFN) )
> > +    {
> > +        id_addr = mfn_to_maddr(trampoline_start);
> > +    }
> > +
> >       if ( enable )
> >           rc = map_pages_to_xen(id_addr, maddr_to_mfn(id_addr), 1,
> >                                 PAGE_HYPERVISOR_RX);
> > diff --git a/xen/arch/arm/mmu/smpboot.c b/xen/arch/arm/mmu/smpboot.c
> > index f1cf9252710c..d768dfe065a5 100644
> > --- a/xen/arch/arm/mmu/smpboot.c
> > +++ b/xen/arch/arm/mmu/smpboot.c
> > @@ -72,13 +72,15 @@ static void clear_boot_pagetables(void)
> >       clear_table(boot_third);
> >   }
> >
> > +extern mfn_t trampoline_start;
> > +
> >   static void set_init_ttbr(lpae_t *root)
> Isn't this function not present in the patch series?
Oh. It looks like I forgot to post one patch. Let me resend it.

Cheers,

--
Julien Grall