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-rw-r--r--arch/x86/kvm/vmx/vmenter.S34
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index 799db084a336..90ad7a6246e3 100644
--- a/arch/x86/kvm/vmx/vmenter.S
+++ b/arch/x86/kvm/vmx/vmenter.S
@@ -4,6 +4,7 @@
#include <asm/bitsperlong.h>
#include <asm/kvm_vcpu_regs.h>
#include <asm/nospec-branch.h>
+#include <asm/segment.h>
#define WORD_SIZE (BITS_PER_LONG / 8)
@@ -294,3 +295,36 @@ SYM_FUNC_START(vmread_error_trampoline)
ret
SYM_FUNC_END(vmread_error_trampoline)
+
+SYM_FUNC_START(vmx_do_interrupt_nmi_irqoff)
+ /*
+ * Unconditionally create a stack frame, getting the correct RSP on the
+ * stack (for x86-64) would take two instructions anyways, and RBP can
+ * be used to restore RSP to make objtool happy (see below).
+ */
+ push %_ASM_BP
+ mov %_ASM_SP, %_ASM_BP
+
+#ifdef CONFIG_X86_64
+ /*
+ * Align RSP to a 16-byte boundary (to emulate CPU behavior) before
+ * creating the synthetic interrupt stack frame for the IRQ/NMI.
+ */
+ and $-16, %rsp
+ push $__KERNEL_DS
+ push %rbp
+#endif
+ pushf
+ push $__KERNEL_CS
+ CALL_NOSPEC _ASM_ARG1
+
+ /*
+ * "Restore" RSP from RBP, even though IRET has already unwound RSP to
+ * the correct value. objtool doesn't know the callee will IRET and,
+ * without the explicit restore, thinks the stack is getting walloped.
+ * Using an unwind hint is problematic due to x86-64's dynamic alignment.
+ */
+ mov %_ASM_BP, %_ASM_SP
+ pop %_ASM_BP
+ ret
+SYM_FUNC_END(vmx_do_interrupt_nmi_irqoff)