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-rw-r--r--arch/x86/kvm/vmx/vmenter.S58
1 files changed, 58 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index 81ada2ce99e7..861ae40e7144 100644
--- a/arch/x86/kvm/vmx/vmenter.S
+++ b/arch/x86/kvm/vmx/vmenter.S
@@ -234,3 +234,61 @@ SYM_FUNC_START(__vmx_vcpu_run)
2: mov $1, %eax
jmp 1b
SYM_FUNC_END(__vmx_vcpu_run)
+
+/**
+ * vmread_error_trampoline - Trampoline from inline asm to vmread_error()
+ * @field: VMCS field encoding that failed
+ * @fault: %true if the VMREAD faulted, %false if it failed
+
+ * Save and restore volatile registers across a call to vmread_error(). Note,
+ * all parameters are passed on the stack.
+ */
+SYM_FUNC_START(vmread_error_trampoline)
+ push %_ASM_BP
+ mov %_ASM_SP, %_ASM_BP
+
+ push %_ASM_AX
+ push %_ASM_CX
+ push %_ASM_DX
+#ifdef CONFIG_X86_64
+ push %rdi
+ push %rsi
+ push %r8
+ push %r9
+ push %r10
+ push %r11
+#endif
+#ifdef CONFIG_X86_64
+ /* Load @field and @fault to arg1 and arg2 respectively. */
+ mov 3*WORD_SIZE(%rbp), %_ASM_ARG2
+ mov 2*WORD_SIZE(%rbp), %_ASM_ARG1
+#else
+ /* Parameters are passed on the stack for 32-bit (see asmlinkage). */
+ push 3*WORD_SIZE(%ebp)
+ push 2*WORD_SIZE(%ebp)
+#endif
+
+ call vmread_error
+
+#ifndef CONFIG_X86_64
+ add $8, %esp
+#endif
+
+ /* Zero out @fault, which will be popped into the result register. */
+ _ASM_MOV $0, 3*WORD_SIZE(%_ASM_BP)
+
+#ifdef CONFIG_X86_64
+ pop %r11
+ pop %r10
+ pop %r9
+ pop %r8
+ pop %rsi
+ pop %rdi
+#endif
+ pop %_ASM_DX
+ pop %_ASM_CX
+ pop %_ASM_AX
+ pop %_ASM_BP
+
+ ret
+SYM_FUNC_END(vmread_error_trampoline)