x86/boot: Move SEV startup code into startup/

Move the SEV startup code into arch/x86/boot/startup/, where it will
reside along with other code that executes extremely early, and
therefore needs to be built in a special manner.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Loughlin <kevinloughlin@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20250418141253.2601348-12-ardb+git@google.com

5 files changed, 5 insertions, 21 deletions

diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 714e30c66eae..478c65149cf0 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -144,7 +144,7 @@ int svsm_perform_call_protocol(struct svsm_call *call);
 u8 snp_vmpl;
 
 /* Include code for early handlers */
-#include "../../coco/sev/shared.c"
+#include "../../boot/startup/sev-shared.c"
 
 int svsm_perform_call_protocol(struct svsm_call *call)
 {
diff --git a/arch/x86/boot/startup/Makefile b/arch/x86/boot/startup/Makefile
index bb7c826e586c..21d911b61459 100644
--- a/arch/x86/boot/startup/Makefile
+++ b/arch/x86/boot/startup/Makefile
@@ -17,7 +17,7 @@ UBSAN_SANITIZE	:= n
 KCOV_INSTRUMENT	:= n
 
 obj-$(CONFIG_X86_64)		+= gdt_idt.o map_kernel.o
-obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= sme.o
+obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= sme.o sev-startup.o
 
 lib-$(CONFIG_X86_64)		+= la57toggle.o
 lib-$(CONFIG_EFI_MIXED)		+= efi-mixed.o
diff --git a/arch/x86/coco/sev/shared.c b/arch/x86/boot/startup/sev-shared.c
index 815542295f16..815542295f16 100644
--- a/arch/x86/coco/sev/shared.c
+++ b/arch/x86/boot/startup/sev-shared.c
diff --git a/arch/x86/coco/sev/startup.c b/arch/x86/boot/startup/sev-startup.c
index 9f5dc70cfb44..10b636009d1c 100644
--- a/arch/x86/coco/sev/startup.c
+++ b/arch/x86/boot/startup/sev-startup.c
@@ -422,7 +422,7 @@ static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt)
 }
 
 /* Include code shared with pre-decompression boot stage */
-#include "shared.c"
+#include "sev-shared.c"
 
 noinstr void __sev_put_ghcb(struct ghcb_state *state)
 {
diff --git a/arch/x86/coco/sev/Makefile b/arch/x86/coco/sev/Makefile
index 57e25f946663..2919dcfc4b02 100644
--- a/arch/x86/coco/sev/Makefile
+++ b/arch/x86/coco/sev/Makefile
@@ -1,25 +1,9 @@
 # SPDX-License-Identifier: GPL-2.0
 
-obj-y += core.o sev-nmi.o startup.o
-
-# jump tables are emitted using absolute references in non-PIC code
-# so they cannot be used in the early SEV startup code
-CFLAGS_startup.o += -fno-jump-tables
-
-ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_startup.o = -pg
-endif
-
-KASAN_SANITIZE_startup.o	:= n
-KMSAN_SANITIZE_startup.o	:= n
-KCOV_INSTRUMENT_startup.o	:= n
-
-# With some compiler versions the generated code results in boot hangs, caused
-# by several compilation units. To be safe, disable all instrumentation.
-KCSAN_SANITIZE		:= n
+obj-y += core.o sev-nmi.o
 
 # Clang 14 and older may fail to respect __no_sanitize_undefined when inlining
-UBSAN_SANITIZE		:= n
+UBSAN_SANITIZE_sev-nmi.o	:= n
 
 # GCC may fail to respect __no_sanitize_address when inlining
 KASAN_SANITIZE_sev-nmi.o	:= n