Re: [PATCH v5 14/44] x86/boot: transition relocation calculations to struct boot_module

["Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>]

On 10/7/24 16:44, Jason Andryuk wrote:
> On 2024-10-06 17:49, Daniel P. Smith wrote:
> > Use struct boot_module fields, start and size, when calculating the 
> > relocation
> > address and size. It also ensures that early_mod references are kept 
> > in sync.
> > Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
> > ---
> >   xen/arch/x86/setup.c | 36 +++++++++++++++++-------------------
> >   1 file changed, 17 insertions(+), 19 deletions(-)
> >
> > diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
> > index f968758048ed..4f540c461b26 100644
> > --- a/xen/arch/x86/setup.c
> > +++ b/xen/arch/x86/setup.c
> > @@ -1490,7 +1490,7 @@ void asmlinkage __init noreturn 
> > __start_xen(unsigned long mbi_p)
> >               struct boot_module *bm = &bi->mods[j];
> >               unsigned long size;
> > -            size = PAGE_ALIGN(bm->headroom + bm->mod->mod_end);
> > +            size = PAGE_ALIGN(bm->headroom + bm->size);
> Is there a mismatch from mod_end in PFNs to bm->size in bytes?  Or is 
> mod_start in pfns and mod_end in bytes?
The conversion is the latter, mod_start is in PFN and mod_end is in bytes.

> >               if ( bi->mods[j].flags & BOOTMOD_FLAG_X86_RELOCATED )
> >                   continue;
> > @@ -1504,13 +1504,13 @@ void asmlinkage __init noreturn 
> > __start_xen(unsigned long mbi_p)
> >               if ( s < end &&
> >                    (bm->headroom ||
> > -                  ((end - size) >> PAGE_SHIFT) > bm->mod->mod_start) )
> > +                  paddr_to_pfn(end - size) > paddr_to_pfn(bm->start)) )
> Drop the paddr_to_pfn if both sides are now in bytes?
True, both are in addresses, will drop.

> >               {
> > -                move_memory(end - size + bm->headroom,
> > -                            (uint64_t)bm->mod->mod_start << PAGE_SHIFT,
> > -                            bm->mod->mod_end);
> > -                bm->mod->mod_start = (end - size) >> PAGE_SHIFT;
> > -                bm->mod->mod_end += bm->headroom;
> > +                move_memory(end - size + bm->headroom, bm->start, 
> > bm->size);
> > +                bm->start = (end - size);
> > +                bm->mod->mod_start = paddr_to_pfn(bm->start);
> > +                bm->size += bm->headroom;
> > +                bm->mod->mod_end = bm->size;
> >                   bm->flags |= BOOTMOD_FLAG_X86_RELOCATED;
> >               }
> >           }
> > @@ -1700,13 +1698,13 @@ void asmlinkage __init noreturn 
> > __start_xen(unsigned long mbi_p)
> >       for ( i = 0; i < bi->nr_modules; ++i )
> >       {
> > -        set_pdx_range(bi->mods[i].mod->mod_start,
> > -                      bi->mods[i].mod->mod_start +
> > -                      PFN_UP(bi->mods[i].mod->mod_end));
> > +        set_pdx_range(paddr_to_pfn(bi->mods[i].mod->mod_start),
> > +                      paddr_to_pfn(bi->mods[i].mod->mod_start) +
> Shouldn't these be
>      paddr_to_pfn(bi->mods[i].start)
> ?
Correct, will fix.

> > +                      PFN_UP(bi->mods[i].size));
> >           map_pages_to_xen(
> > -            (unsigned long)mfn_to_virt(bi->mods[i].mod->mod_start),
> > -            _mfn(bi->mods[i].mod->mod_start),
> > -            PFN_UP(bi->mods[i].mod->mod_end), PAGE_HYPERVISOR);
> > +            (unsigned long)maddr_to_virt(bi->mods[i].start),
> > +            maddr_to_mfn(bi->mods[i].start),
> > +            PFN_UP(bi->mods[i].size), PAGE_HYPERVISOR);
> First argument should fit on same line as map_pages_to_xen().
If it fits, yes I will move it up.

v/r,
dps