KVM: VMX: Add a trampoline to fix VMREAD error handling

[tomoyo/tomoyo-test1.git] / arch / x86 / kvm / vmx / vmenter.S

diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index ca20651..9651ba3 100644 (file)
--- 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)