Commit 597cfe48 authored by Joerg Roedel's avatar Joerg Roedel Committed by Borislav Petkov
Browse files

x86/boot/compressed/64: Setup a GHCB-based VC Exception handler 



Install an exception handler for #VC exception that uses a GHCB. Also
add the infrastructure for handling different exit-codes by decoding
the instruction that caused the exception and error handling.

Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-24-joro@8bytes.org
parent c81d6002

arch/x86/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -1521,6 +1521,7 @@ config AMD_MEM_ENCRYPT 
	select DYNAMIC_PHYSICAL_MASK

	select ARCH_USE_MEMREMAP_PROT

	select ARCH_HAS_FORCE_DMA_UNENCRYPTED

	select INSTRUCTION_DECODER

	help

	  Say yes to enable support for the encryption of system memory.

	  This requires an AMD processor that supports Secure Memory

arch/x86/boot/compressed/Makefile

+5 −0
Original line number Diff line number Diff line
@@ -44,6 +44,11 @@ KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) 
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables

KBUILD_CFLAGS += -D__DISABLE_EXPORTS



# sev-es.c indirectly inludes inat-table.h which is generated during

# compilation and stored in $(objtree). Add the directory to the includes so

# that the compiler finds it even with out-of-tree builds (make O=/some/path).

CFLAGS_sev-es.o += -I$(objtree)/arch/x86/lib/



KBUILD_AFLAGS  := $(KBUILD_CFLAGS) -D__ASSEMBLY__

GCOV_PROFILE := n

UBSAN_SANITIZE :=n

arch/x86/boot/compressed/idt_64.c

+4 −0
Original line number Diff line number Diff line
@@ -46,5 +46,9 @@ void load_stage2_idt(void) 


	set_idt_entry(X86_TRAP_PF, boot_page_fault);



#ifdef CONFIG_AMD_MEM_ENCRYPT

	set_idt_entry(X86_TRAP_VC, boot_stage2_vc);

#endif



	load_boot_idt(&boot_idt_desc);

}

arch/x86/boot/compressed/idt_handlers_64.S

+2 −1
Original line number Diff line number Diff line
@@ -73,4 +73,5 @@ EXCEPTION_HANDLER boot_page_fault do_boot_page_fault error_code=1 


#ifdef CONFIG_AMD_MEM_ENCRYPT

EXCEPTION_HANDLER	boot_stage1_vc do_vc_no_ghcb		error_code=1

EXCEPTION_HANDLER	boot_stage2_vc do_boot_stage2_vc	error_code=1

#endif

arch/x86/boot/compressed/misc.c

+7 −0
Original line number Diff line number Diff line
@@ -442,6 +442,13 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, 
	parse_elf(output);

	handle_relocations(output, output_len, virt_addr);

	debug_putstr("done.\nBooting the kernel.\n");



	/*

	 * Flush GHCB from cache and map it encrypted again when running as

	 * SEV-ES guest.

	 */

	sev_es_shutdown_ghcb();



	return output;

}

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