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authorArd Biesheuvel <ardb@kernel.org>2022-11-22 17:10:12 +0100
committerBorislav Petkov <bp@suse.de>2022-11-24 08:57:41 +0100
commit9ea813be3d345dfb8ac5bf6fbb29e6a63647a39d (patch)
tree962e9e605711b13f6231a80e0d74bba21a7c44c5 /arch/x86/boot/compressed/mem_encrypt.S
parentc6355995ba471d7ad574174e593192ce805c7e1a (diff)
downloadlinux-9ea813be3d345dfb8ac5bf6fbb29e6a63647a39d.tar.bz2
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: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20221122161017.2426828-13-ardb@kernel.org
Diffstat (limited to 'arch/x86/boot/compressed/mem_encrypt.S')
-rw-r--r--arch/x86/boot/compressed/mem_encrypt.S72
1 files changed, 71 insertions, 1 deletions
diff --git a/arch/x86/boot/compressed/mem_encrypt.S b/arch/x86/boot/compressed/mem_encrypt.S
index a73e4d783cae..6747e5e4c696 100644
--- a/arch/x86/boot/compressed/mem_encrypt.S
+++ b/arch/x86/boot/compressed/mem_encrypt.S
@@ -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