[U-Boot] [PATCH v5 03/13] efi: sandbox: Adjust memory usage for sandbox

[Simon Glass]

Hi Alex,

On 12 June 2018 at 02:05, Alexander Graf <agraf at suse.de> wrote:
>
>
> On 12.06.18 07:26, Simon Glass wrote:
>> With sandbox the U-Boot code is not mapped into the sandbox memory range
>> so does not need to be excluded when allocating EFI memory. Update the EFI
>> memory init code to take account of that.
>>
>> Also use mapmem instead of a cast to convert a memory address to a
>> pointer.
>>
>> Signed-off-by: Simon Glass <sjg at chromium.org>
>> ---
>>
>> Changes in v5: None
>> Changes in v4: None
>> Changes in v3: None
>> Changes in v2:
>> - Update to use mapmem instead of a cast
>>
>>  lib/efi_loader/efi_memory.c | 31 ++++++++++++++++++-------------
>>  1 file changed, 18 insertions(+), 13 deletions(-)
>>
>> diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
>> index ec66af98ea..210e49ee8b 100644
>> --- a/lib/efi_loader/efi_memory.c
>> +++ b/lib/efi_loader/efi_memory.c
>> @@ -9,6 +9,7 @@
>>  #include <efi_loader.h>
>>  #include <inttypes.h>
>>  #include <malloc.h>
>> +#include <mapmem.h>
>>  #include <watchdog.h>
>>  #include <linux/list_sort.h>
>>
>> @@ -393,7 +394,7 @@ efi_status_t efi_allocate_pool(int pool_type, efi_uintn_t size, void **buffer)
>>                              &t);
>>
>>       if (r == EFI_SUCCESS) {
>> -             struct efi_pool_allocation *alloc = (void *)(uintptr_t)t;
>> +             struct efi_pool_allocation *alloc = map_sysmem(t, size);
>
> We want to eventually be able to run efi binaries inside sandbox, so we
> need to expose a 1:1 memory map inside the efi interfaces.
>
> That means the memory argument of efi_allocate_pages() already needs to
> be set to the virtual address in real VA space. The easiest way to get
> there is if you just put virtual addresses in the efi memory map.

Can you please explain that a bit more, or give a code example? I'm
not quite sure what you mean.

>
>>               alloc->num_pages = num_pages;
>>               *buffer = alloc->data;
>>       }
>> @@ -504,18 +505,22 @@ int efi_memory_init(void)
>>
>>       efi_add_known_memory();
>>
>> -     /* Add U-Boot */
>> -     uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK;
>> -     uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT;
>> -     efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false);
>> -
>> -     /* Add Runtime Services */
>> -     runtime_start = (ulong)&__efi_runtime_start & ~EFI_PAGE_MASK;
>> -     runtime_end = (ulong)&__efi_runtime_stop;
>> -     runtime_end = (runtime_end + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
>> -     runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
>> -     efi_add_memory_map(runtime_start, runtime_pages,
>> -                        EFI_RUNTIME_SERVICES_CODE, false);
>> +     if (!IS_ENABLED(CONFIG_SANDBOX)) {
>> +             /* Add U-Boot */
>> +             uboot_start = (gd->start_addr_sp - uboot_stack_size) &
>> +                             ~EFI_PAGE_MASK;
>> +             uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT;
>> +             efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA,
>> +                                false);
>
> I guess it's ok to hide U-Boot from the payload for sandbox, yes. Please
> extract the code into a function though, so that we don't get into too
> much indenting.
>

OK

>> +
>> +             /* Add Runtime Services */
>> +             runtime_start = (ulong)&__efi_runtime_start & ~EFI_PAGE_MASK;
>> +             runtime_end = (ulong)&__efi_runtime_stop;
>> +             runtime_end = (runtime_end + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
>> +             runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
>> +             efi_add_memory_map(runtime_start, runtime_pages,
>> +                                EFI_RUNTIME_SERVICES_CODE, false);
>> +     }
>
> I guess we do want to indicate RTS, no? But like everything else we want
> to expose it with the real VA addresses.

I suspect it would never be used but also that we should indicate RTS
is present so that things that check for it don't fail. What do you
think we should do here?

Regards,
Simon