diff mbox series

[kvm-unit-tests,3/3] x86: replace segment selector magic number with macro definition

Message ID 20250221225406.2228938-4-seanjc@google.com (mailing list archive)
State New
Headers show
Series x86: Use macros for selectors in asm | expand

Commit Message

Sean Christopherson Feb. 21, 2025, 10:54 p.m. UTC 
From: Hang SU <darcysail@gmail.com>

Add assembly check in desc.h, to replace segment selector
magic number with macro definition.

Signed-off-by: Hang SU <darcy.sh@antgroup.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 lib/x86/desc.h    | 7 ++++++-
 x86/cstart64.S    | 8 ++++----
 x86/trampolines.S | 8 +++++---
 3 files changed, 15 insertions(+), 8 deletions(-)

Comments

Sean Christopherson Feb. 21, 2025, 11:34 p.m. UTC | #1 
On Fri, Feb 21, 2025, Sean Christopherson wrote:
> @@ -15,7 +17,7 @@ sipi_entry:
>  	or $1, %eax
>  	mov %eax, %cr0
>  	lgdtl ap_rm_gdt_descr - sipi_entry
> -	ljmpl $8, $ap_start32
> +	ljmpl $KERNEL_CS32, $ap_start32

Gah, this is wrong, it should be KERNEL_CS, not KERNEL_CS32.  It was wrong in the
original posting as well.  Not sure how I missed it the first time around.

I'll fixup when applying.
diff mbox series

Patch

diff --git a/lib/x86/desc.h b/lib/x86/desc.h
index aa6213d1..5634de94 100644
--- a/lib/x86/desc.h
+++ b/lib/x86/desc.h
@@ -69,6 +69,8 @@ 
 #define __ASM_SEL(a,b)		__ASM_FORM(b)
 #endif
 
+#ifndef __ASSEMBLER__
+
 #include <setjmp.h>
 
 void setup_idt(void);
@@ -338,4 +340,7 @@  do {									\
 
 #define asm_safe_report_ex __asm_safe_report
 
-#endif
+
+#endif /* __ASSEMBLER__ */
+
+#endif /* _X86_DESC_H_ */
diff --git a/x86/cstart64.S b/x86/cstart64.S
index 4dff1102..2b14c076 100644
--- a/x86/cstart64.S
+++ b/x86/cstart64.S
@@ -1,5 +1,5 @@ 
-
 #include "apic-defs.h"
+#include "desc.h"
 
 ipi_vector = 0x20
 
@@ -66,7 +66,7 @@  start:
 	mov $stacktop, %esp
 	setup_percpu_area
 	call prepare_64
-	jmpl $8, $start64
+	jmpl $KERNEL_CS, $start64
 
 switch_to_5level:
 	/* Disable CR4.PCIDE */
@@ -86,11 +86,11 @@  switch_to_5level:
 	bts $12, %eax
 	mov %eax, %cr4
 
-	mov $0x10, %ax
+	mov $KERNEL_DS, %ax
 	mov %ax, %ss
 
 	call enter_long_mode
-	jmpl $8, $lvl5
+	jmpl $KERNEL_CS, $lvl5
 
 smp_stacktop:	.long stacktop - 4096
 
diff --git a/x86/trampolines.S b/x86/trampolines.S
index 6a3df9c1..f0b05ab5 100644
--- a/x86/trampolines.S
+++ b/x86/trampolines.S
@@ -3,6 +3,8 @@ 
  * transition from 32-bit to 64-bit code (x86-64 only)
  */
 
+#include "desc.h"
+
  /* EFI provides it's own SIPI sequence to handle relocation. */
 #ifndef CONFIG_EFI
 .code16
@@ -15,7 +17,7 @@  sipi_entry:
 	or $1, %eax
 	mov %eax, %cr0
 	lgdtl ap_rm_gdt_descr - sipi_entry
-	ljmpl $8, $ap_start32
+	ljmpl $KERNEL_CS32, $ap_start32
 sipi_end:
 
 .globl ap_rm_gdt_descr
@@ -66,7 +68,7 @@  MSR_GS_BASE = 0xc0000101
 	mov $MSR_GS_BASE, %ecx
 	rdmsr
 
-	mov $0x10, %bx
+	mov $KERNEL_DS, %bx
 	mov %bx, %ds
 	mov %bx, %es
 	mov %bx, %fs
@@ -123,7 +125,7 @@  ap_start32:
 	call prepare_64
 
 	load_absolute_addr $ap_start64, %edx
-	pushl $0x08
+	pushl $KERNEL_CS
 	pushl %edx
 	lretl
 #endif