TDX guests are not allowed to clear CR4.MCE. Attempt to clear it leads to #VE. Preserve the flag during kexec. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> --- arch/x86/kernel/relocate_kernel_64.S | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 4a73351f87f8..18f19dcc40e9 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -145,8 +145,12 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) * Set cr4 to a known state: * - physical address extension enabled * - 5-level paging, if it was enabled before + * - Preserve MCE, if it was set. Clearing MCE may fault in some + * environments. */ - movl $X86_CR4_PAE, %eax + movq %cr4, %rax + andl $X86_CR4_MCE, %eax + orl $X86_CR4_PAE, %eax testq $X86_CR4_LA57, %r13 jz 1f orl $X86_CR4_LA57, %eax -- 2.39.1 _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
