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authorLinus Torvalds <torvalds@linux-foundation.org>2019-02-03 09:08:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-02-03 09:08:12 -0800
commit24b888d8d59847871387aa3b241b524661070a6e (patch)
tree9c48641b881abd4687ffe7469083646478ebe9f1 /arch/x86/boot/compressed/head_64.S
parentcc6810e36bd875f197fcd6c74ad01f48090ecc05 (diff)
parente6d429313ea5c776d2e76b4494df69102e6b7115 (diff)
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner: "A few updates for x86: - Fix an unintended sign extension issue in the fault handling code - Rename the new resource control config switch so it's less confusing - Avoid setting up EFI info in kexec when the EFI runtime is disabled. - Fix the microcode version check in the AMD microcode loader so it only loads higher version numbers and never downgrades - Set EFER.LME in the 32bit trampoline before returning to long mode to handle older AMD/KVM behaviour properly. - Add Darren and Andy as x86/platform reviewers" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/resctrl: Avoid confusion over the new X86_RESCTRL config x86/kexec: Don't setup EFI info if EFI runtime is not enabled x86/microcode/amd: Don't falsely trick the late loading mechanism MAINTAINERS: Add Andy and Darren as arch/x86/platform/ reviewers x86/fault: Fix sign-extend unintended sign extension x86/boot/compressed/64: Set EFER.LME=1 in 32-bit trampoline before returning to long mode x86/cpu: Add Atom Tremont (Jacobsville)
Diffstat (limited to 'arch/x86/boot/compressed/head_64.S')
-rw-r--r--arch/x86/boot/compressed/head_64.S8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 64037895b085..f105ae8651c9 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -600,6 +600,14 @@ ENTRY(trampoline_32bit_src)
leal TRAMPOLINE_32BIT_PGTABLE_OFFSET(%ecx), %eax
movl %eax, %cr3
3:
+ /* Set EFER.LME=1 as a precaution in case hypervsior pulls the rug */
+ pushl %ecx
+ movl $MSR_EFER, %ecx
+ rdmsr
+ btsl $_EFER_LME, %eax
+ wrmsr
+ popl %ecx
+
/* Enable PAE and LA57 (if required) paging modes */
movl $X86_CR4_PAE, %eax
cmpl $0, %edx