2 files changed, 48 insertions, 0 deletions
diff --git a/OvmfPkg/XenBusDxe/X64/hypercall.S b/OvmfPkg/XenBusDxe/X64/hypercall.S
new file mode 100644
index 0000000000..83cf466953
--- /dev/null
+++ b/OvmfPkg/XenBusDxe/X64/hypercall.S
@@ -0,0 +1,22 @@
+# INTN
+# EFIAPI
+# XenHypercall2 (
+#   IN     VOID *HypercallAddr,
+#   IN OUT INTN Arg1,
+#   IN OUT INTN Arg2
+#   );
+ASM_GLOBAL ASM_PFX(XenHypercall2)
+ASM_PFX(XenHypercall2):
+  push %rdi
+  push %rsi
+  # Copy HypercallAddr to rax
+  movq %rcx, %rax
+  # Copy Arg1 to the register expected by Xen
+  movq %rdx, %rdi
+  # Copy Arg2 to the register expected by Xen
+  movq %r8, %rsi
+  # Call HypercallAddr
+  call *%rax
+  pop %rsi
+  pop %rdi
+  ret
diff --git a/OvmfPkg/XenBusDxe/X64/hypercall.asm b/OvmfPkg/XenBusDxe/X64/hypercall.asm
new file mode 100644
index 0000000000..5b3451473d
--- /dev/null
+++ b/OvmfPkg/XenBusDxe/X64/hypercall.asm
@@ -0,0 +1,26 @@
+.code
+
+; INTN
+; EFIAPI
+; XenHypercall2 (
+;   IN     VOID *HypercallAddr,
+;   IN OUT INTN Arg1,
+;   IN OUT INTN Arg2
+;   );
+XenHypercall2 PROC
+  push rdi
+  push rsi
+  ; Copy HypercallAddr to rax
+  mov rax, rcx
+  ; Copy Arg1 to the register expected by Xen
+  mov rdi, rdx
+  ; Copy Arg2 to the register expected by Xen
+  mov rsi, r8
+  ; Call HypercallAddr
+  call rax
+  pop rsi
+  pop rdi
+  ret
+XenHypercall2 ENDP
+
+END