diff options
| author | H. Peter Anvin <hpa@zytor.com> | 2008-01-30 13:33:02 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:33:02 +0100 |
| commit | 88089519f302f1296b4739be45699f06f728ec31 (patch) | |
| tree | a0ffb023be68d0b83503e77ba4a9d9b43acea88b | |
| parent | c4d9ba6da9f050ebb7e0d70769e3dca0fd45334f (diff) | |
x86 setup: initialize LDTR and TR to make life easier to Intel VT
Intel VT doesn't like to engage when the protected-mode state isn't
fully initialized. Make life easier for it by initializing LDTR (to
null) and TR (to a dummy hunk of low memory which will never actually
be touched.)
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | arch/x86/boot/pm.c | 4 | ||||
| -rw-r--r-- | arch/x86/boot/pmjump.S | 7 | ||||
| -rw-r--r-- | include/asm-x86/segment.h | 3 |
3 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/boot/pm.c b/arch/x86/boot/pm.c index 09fb342cc62e..b23cbdc7d547 100644 --- a/arch/x86/boot/pm.c +++ b/arch/x86/boot/pm.c @@ -121,6 +121,10 @@ static void setup_gdt(void) [GDT_ENTRY_BOOT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff), /* DS: data, read/write, 4 GB, base 0 */ [GDT_ENTRY_BOOT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff), + /* TSS: 32-bit tss, 104 bytes, base 4096 */ + /* We only have a TSS here to keep Intel VT happy; + we don't actually use it for anything. */ + [GDT_ENTRY_BOOT_TSS] = GDT_ENTRY(0x0089, 4096, 103), }; /* Xen HVM incorrectly stores a pointer to the gdt_ptr, instead of the gdt_ptr contents. Thus, make it static so it will diff --git a/arch/x86/boot/pmjump.S b/arch/x86/boot/pmjump.S index ef0da1f2c7fd..f7153d0d476e 100644 --- a/arch/x86/boot/pmjump.S +++ b/arch/x86/boot/pmjump.S @@ -36,6 +36,7 @@ protected_mode_jump: addl %ebx, 2f movw $__BOOT_DS, %cx + movw $__BOOT_TSS, %di movl %cr0, %edx orb $1, %dl # Protected mode (PE) bit @@ -63,6 +64,9 @@ in_pm32: # a valid stack if some debugging hack wants to use it. addl %ebx, %esp + # Set up TR to make Intel VT happy + ltr %di + # Clear registers to allow for future extensions to the # 32-bit boot protocol xorl %ecx, %ecx @@ -71,6 +75,9 @@ in_pm32: xorl %ebp, %ebp xorl %edi, %edi + # Set up LDTR to make Intel VT happy + lldt %cx + jmpl *%eax # Jump to the 32-bit entrypoint .size in_pm32, .-in_pm32 diff --git a/include/asm-x86/segment.h b/include/asm-x86/segment.h index 1ff05a9f5513..57c8d3723836 100644 --- a/include/asm-x86/segment.h +++ b/include/asm-x86/segment.h @@ -9,6 +9,9 @@ #define GDT_ENTRY_BOOT_DS (GDT_ENTRY_BOOT_CS + 1) #define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8) +#define GDT_ENTRY_BOOT_TSS (GDT_ENTRY_BOOT_CS + 2) +#define __BOOT_TSS (GDT_ENTRY_BOOT_TSS * 8) + #ifdef CONFIG_X86_32 /* * The layout of the per-CPU GDT under Linux: |