[PATCH v8 1/2] x86/boot: Align mbi2.c stack to 16 bytes

[Frediano Ziglio <frediano.ziglio@cloud.com>]

Doing previous testing with an Adler Lake Intel machine the following
patch (improving MBI structure checking) started to fail.
Excluding it makes the tests succeed however there was not apparent
reason (looking at the code) for the failure.
So I instrumented code to output the structure and tested code with
this extracted data with and without the following patch and results
were the same.
Compiled assembly code from lab was also fine beside not keeping
the 16-byte alignment for the stack.
Turning on stack alignment solve the problem on Adler Lake machine.

Signed-off-by: Frediano Ziglio <frediano.ziglio@cloud.com>
---
 xen/arch/x86/efi/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xen/arch/x86/efi/Makefile b/xen/arch/x86/efi/Makefile
index 7e2b5c07de..c2cad86856 100644
--- a/xen/arch/x86/efi/Makefile
+++ b/xen/arch/x86/efi/Makefile
@@ -11,6 +11,8 @@ $(obj)/boot.init.o: $(obj)/buildid.o
 $(call cc-option-add,cflags-stack-boundary,CC,-mpreferred-stack-boundary=4)
 $(addprefix $(obj)/,$(EFIOBJ-y)): CFLAGS_stack_boundary := $(cflags-stack-boundary)
 
+$(obj)/mbi2.o: CFLAGS_stack_boundary := $(cflags-stack-boundary)
+
 obj-y := common-stub.o stub.o
 obj-$(XEN_BUILD_EFI) := $(filter-out %.init.o,$(EFIOBJ-y))
 obj-bin-$(XEN_BUILD_EFI) := $(filter %.init.o,$(EFIOBJ-y))
-- 
2.34.1