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diff --git a/guest/linux/hvm-ros/v3_hvm_ros_user_low_level.S b/guest/linux/hvm-ros/v3_hvm_ros_user_low_level.S
new file mode 100644
index 0000000..3cbcc07
--- /dev/null
+++ b/guest/linux/hvm-ros/v3_hvm_ros_user_low_level.S
@@ -0,0 +1,88 @@
+.section .text
+	
+.extern __v3_hvm_ros_signal_handler  
+
+/* 
+   This is the entry point for signal dispatch
+   from the VMM.
+	
+   VMM invokes this stub when a user signal is
+   raised and:	the relevant address space
+   is active, and we are at user-level.
+   It will be invoked  on exactly one core,  
+   although there are  no guarantees on which one.
+   
+*/
+
+
+#define GPR_SAVE()                                               \
+	pushq %rbp              ;                                \
+	pushq %rax      	;                                \
+	pushq %rbx      	;                                \
+	pushq %rcx      	;                                \
+	pushq %rdx      	;                                \
+	pushq %rsi      	;                                \
+	pushq %rdi      	;                                \
+	pushq %r8       	;                                \
+	pushq %r9       	;                                \
+	pushq %r10      	;                                \
+	pushq %r11      	;                                \
+	pushq %r12      	;                                \
+	pushq %r13      	;                                \
+	pushq %r14      	;                                \
+	pushq %r15      	;                                \
+
+#define GPR_LOAD()                       \
+	popq %r15       	;                                \
+	popq %r14       	;                                \
+	popq %r13       	;                                \
+	popq %r12       	;                                \
+	popq %r11       	;                                \
+	popq %r10       	;                                \
+	popq %r9        	;                                \
+	popq %r8        	;                                \
+	popq %rdi       	;                                \
+	popq %rsi       	;                                \
+	popq %rdx       	;                                \
+	popq %rcx       	;                                \
+	popq %rbx       	;                                \
+	popq %rax               ;                                \
+	popq %rbp               ;          
+
+	
+/*
+   The VMM puts us here with what looks like a long mode 
+   interrupt dispatch, but it's from CPL 3 to CPL 3 and
+   it's not done as an interrupt injection per se, so
+   we can be interrupted, and deliverable interrupts
+   automatically prioritize over us.
+
+        48bitsblank | return SS (16 bits)
+	Return RSP
+	Return RFLAGS
+	48bitsblank | return CS (16 bits)
+	Return RIP
+	ERROR CODE (HVM-specific non-zero number here)  <- RSP on entry
+	
+	We then need simply to do this:
+
+	save regs
+	call the handler (if installed)
+	restore regs
+	iret
+	
+*/
+
+.global __v3_hvm_ros_signal_handler_stub
+__v3_hvm_ros_signal_handler_stub:
+	GPR_SAVE()
+	movabs __v3_hvm_ros_signal_handler, %rax
+	testq %rax, %rax
+	jz skip_handler
+	movq 120(%rsp), %rdi /* error code becomes argument */
+	callq *%rax	
+skip_handler:	
+	GPR_LOAD()
+	addq $8, %rsp /* nuke the error code */
+	iretq
+