diff options
Diffstat (limited to 'arch/x86/realmode')
| -rw-r--r-- | arch/x86/realmode/rm/trampoline_64.S | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/x86/realmode/rm/trampoline_64.S b/arch/x86/realmode/rm/trampoline_64.S index d380f2d1fd23..e38d61d6562e 100644 --- a/arch/x86/realmode/rm/trampoline_64.S +++ b/arch/x86/realmode/rm/trampoline_64.S @@ -143,11 +143,22 @@ SYM_CODE_START(startup_32) movl %eax, %cr3 # Set up EFER + movl $MSR_EFER, %ecx + rdmsr + /* + * Skip writing to EFER if the register already has desired + * value (to avoid #VE for the TDX guest). + */ + cmp pa_tr_efer, %eax + jne .Lwrite_efer + cmp pa_tr_efer + 4, %edx + je .Ldone_efer +.Lwrite_efer: movl pa_tr_efer, %eax movl pa_tr_efer + 4, %edx - movl $MSR_EFER, %ecx wrmsr +.Ldone_efer: # Enable paging and in turn activate Long Mode. movl $CR0_STATE, %eax movl %eax, %cr0 |