Commit 9ea813be authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Borislav Petkov
Browse files

x86/boot/compressed: Move startup32_load_idt() out of head_64.S 



Now that startup32_load_idt() has been refactored into an ordinary
callable function, move it into mem-encrypt.S where it belongs.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221122161017.2426828-13-ardb@kernel.org
parent c6355995

arch/x86/boot/compressed/head_64.S

+0 −72
Original line number Diff line number Diff line
@@ -707,78 +707,6 @@ SYM_DATA_START(boot_idt) 
	.endr

SYM_DATA_END_LABEL(boot_idt, SYM_L_GLOBAL, boot_idt_end)



#ifdef CONFIG_AMD_MEM_ENCRYPT

SYM_DATA_START(boot32_idt_desc)

	.word   boot32_idt_end - boot32_idt - 1

	.long   0

SYM_DATA_END(boot32_idt_desc)

	.balign 8

SYM_DATA_START(boot32_idt)

	.rept 32

	.quad 0

	.endr

SYM_DATA_END_LABEL(boot32_idt, SYM_L_GLOBAL, boot32_idt_end)



	.text

	.code32

/*

 * Write an IDT entry into boot32_idt

 *

 * Parameters:

 *

 * %eax:	Handler address

 * %edx:	Vector number

 * %ecx:	IDT address

 */

SYM_FUNC_START_LOCAL(startup32_set_idt_entry)

	/* IDT entry address to %ecx */

	leal	(%ecx, %edx, 8), %ecx



	/* Build IDT entry, lower 4 bytes */

	movl    %eax, %edx

	andl    $0x0000ffff, %edx		# Target code segment offset [15:0]

	orl	$(__KERNEL32_CS << 16), %edx	# Target code segment selector



	/* Store lower 4 bytes to IDT */

	movl    %edx, (%ecx)



	/* Build IDT entry, upper 4 bytes */

	movl    %eax, %edx

	andl    $0xffff0000, %edx	# Target code segment offset [31:16]

	orl     $0x00008e00, %edx	# Present, Type 32-bit Interrupt Gate



	/* Store upper 4 bytes to IDT */

	movl    %edx, 4(%ecx)



	RET

SYM_FUNC_END(startup32_set_idt_entry)



SYM_FUNC_START(startup32_load_idt)

	push	%ebp

	push	%ebx



	call	1f

1:	pop	%ebp



	leal    (boot32_idt - 1b)(%ebp), %ebx



	/* #VC handler */

	leal    (startup32_vc_handler - 1b)(%ebp), %eax

	movl    $X86_TRAP_VC, %edx

	movl	%ebx, %ecx

	call    startup32_set_idt_entry



	/* Load IDT */

	leal	(boot32_idt_desc - 1b)(%ebp), %ecx

	movl	%ebx, 2(%ecx)

	lidt    (%ecx)



	pop	%ebx

	pop	%ebp

	RET

SYM_FUNC_END(startup32_load_idt)

#endif



/*

 * Check for the correct C-bit position when the startup_32 boot-path is used.

 *

arch/x86/boot/compressed/mem_encrypt.S

+71 −1
Original line number Diff line number Diff line
@@ -12,6 +12,8 @@ 
#include <asm/processor-flags.h>

#include <asm/msr.h>

#include <asm/asm-offsets.h>

#include <asm/segment.h>

#include <asm/trapnr.h>



	.text

	.code32
@@ -98,7 +100,7 @@ SYM_CODE_START_LOCAL(sev_es_req_cpuid) 
	jmp	1b

SYM_CODE_END(sev_es_req_cpuid)



SYM_CODE_START(startup32_vc_handler)

SYM_CODE_START_LOCAL(startup32_vc_handler)

	pushl	%eax

	pushl	%ebx

	pushl	%ecx
@@ -184,6 +186,63 @@ SYM_CODE_START(startup32_vc_handler) 
	jmp .Lfail

SYM_CODE_END(startup32_vc_handler)



/*

 * Write an IDT entry into boot32_idt

 *

 * Parameters:

 *

 * %eax:	Handler address

 * %edx:	Vector number

 * %ecx:	IDT address

 */

SYM_FUNC_START_LOCAL(startup32_set_idt_entry)

	/* IDT entry address to %ecx */

	leal	(%ecx, %edx, 8), %ecx



	/* Build IDT entry, lower 4 bytes */

	movl    %eax, %edx

	andl    $0x0000ffff, %edx		# Target code segment offset [15:0]

	orl	$(__KERNEL32_CS << 16), %edx	# Target code segment selector



	/* Store lower 4 bytes to IDT */

	movl    %edx, (%ecx)



	/* Build IDT entry, upper 4 bytes */

	movl    %eax, %edx

	andl    $0xffff0000, %edx	# Target code segment offset [31:16]

	orl     $0x00008e00, %edx	# Present, Type 32-bit Interrupt Gate



	/* Store upper 4 bytes to IDT */

	movl    %edx, 4(%ecx)



	RET

SYM_FUNC_END(startup32_set_idt_entry)



SYM_FUNC_START(startup32_load_idt)

	push	%ebp

	push	%ebx



	call	1f

1:	pop	%ebp



	leal    (boot32_idt - 1b)(%ebp), %ebx



	/* #VC handler */

	leal    (startup32_vc_handler - 1b)(%ebp), %eax

	movl    $X86_TRAP_VC, %edx

	movl	%ebx, %ecx

	call    startup32_set_idt_entry



	/* Load IDT */

	leal	(boot32_idt_desc - 1b)(%ebp), %ecx

	movl	%ebx, 2(%ecx)

	lidt    (%ecx)



	pop	%ebx

	pop	%ebp

	RET

SYM_FUNC_END(startup32_load_idt)



	.code64



#include "../../kernel/sev_verify_cbit.S"
@@ -195,4 +254,15 @@ SYM_CODE_END(startup32_vc_handler) 
SYM_DATA(sme_me_mask,		.quad 0)

SYM_DATA(sev_status,		.quad 0)

SYM_DATA(sev_check_data,	.quad 0)



SYM_DATA_START_LOCAL(boot32_idt)

	.rept	32

	.quad	0

	.endr

SYM_DATA_END(boot32_idt)



SYM_DATA_START_LOCAL(boot32_idt_desc)

	.word	. - boot32_idt - 1

	.long	0

SYM_DATA_END(boot32_idt_desc)

#endif