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>
diff --git a/arch/x86/boot/pmjump.S b/arch/x86/boot/pmjump.S
index ef0da1f..f7153d0 100644
--- a/arch/x86/boot/pmjump.S
+++ b/arch/x86/boot/pmjump.S
@@ -36,6 +36,7 @@
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 @@
# 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 @@
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