Re: [PATCH v2 13/18] xen: init memory regions for PVH

[Juergen Gross <jgross@suse.com>]

On 22/10/2018 13:31, Daniel Kiper wrote:
> On Tue, Oct 09, 2018 at 01:03:12PM +0200, Juergen Gross wrote:
>> Add all usable memory regions to grub memory management and add the
>> needed mmap iterate code.
> 
> I am missing a few words why this patch is needed. Especially why
> grub_machine_mmap_iterate() has to belong to this patch. However,
> I think that it should be introduced by patch in which
> grub_machine_mmap_iterate() is used at some point.

That would again lead to one giant PVH patch which you didn't like.

grub_machine_mmap_iterate() is being used by grub common code like
grub-core/lib/relocator.c or grub-core/mmap/mmap.c

grub_machine_mmap_iterate() belongs into this patch as it is the
main user of the memory map introduced here.


Juergen

> 
>> As we are running in 32-bit mode don't add memory above 4GB.
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> ---
>>  grub-core/kern/i386/xen/pvh.c | 35 +++++++++++++++++++++++++++++++++++
>>  1 file changed, 35 insertions(+)
>>
>> diff --git a/grub-core/kern/i386/xen/pvh.c b/grub-core/kern/i386/xen/pvh.c
>> index 93ed68245..c4a8bccf4 100644
>> --- a/grub-core/kern/i386/xen/pvh.c
>> +++ b/grub-core/kern/i386/xen/pvh.c
>> @@ -222,6 +222,30 @@ grub_xen_get_mmap (void)
>>    grub_xen_sort_mmap ();
>>  }
>>
>> +static void
>> +grub_xen_mm_init_regions (void)
>> +{
>> +  grub_uint64_t modend, from, to;
>> +  unsigned int i;
>> +
>> +  modend = grub_modules_get_end ();
>> +
>> +  for (i = 0; i < nr_map_entries; i++)
>> +    {
>> +      if (map[i].type != GRUB_MEMORY_AVAILABLE)
>> +        continue;
>> +      from = map[i].addr;
>> +      to = from + map[i].len;
>> +      if (from < modend)
>> +        from = modend;
>> +      if (from >= to || from >= 0x100000000ULL)
>> +        continue;
>> +      if (to > 0x100000000ULL)
>> +        to = 0x100000000ULL;
>> +      grub_mm_init_region ((void *) (grub_addr_t) from, to - from);
>> +    }
>> +}
>> +
>>  static grub_uint64_t
>>  grub_xen_find_page (grub_uint64_t start)
>>  {
>> @@ -302,10 +326,21 @@ grub_xen_setup_pvh (void)
>>    grub_xen_shared_info = grub_xen_add_physmap (XENMAPSPACE_shared_info,
>>  					       (void *) par);
>>
>> +  grub_xen_mm_init_regions ();
>> +
>>    grub_rsdp_addr = pvh_start_info->rsdp_paddr;
>>  }
>>
>>  grub_err_t
>>  grub_machine_mmap_iterate (grub_memory_hook_t hook, void *hook_data)
>>  {
>> +  unsigned int i;
>> +
>> +  for (i = 0; i < nr_map_entries; i++)
>> +    {
>> +      if (map[i].len && hook (map[i].addr, map[i].len, map[i].type, hook_data))
>> +        break;
>> +    }
>> +
>> +  return GRUB_ERR_NONE;
> 
> Daniel
>