xen/riscv: introduce vm_event_*() functions

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>

xen/arch/riscv/Makefile

@@ -5,6 +5,7 @@ obj-$(CONFIG_RISCV_64) += riscv64/
 obj-y += sbi.o
 obj-y += setup.o
 obj-y += traps.o
+obj-y += vm_event.o
 
 $(TARGET): $(TARGET)-syms
 	$(OBJCOPY) -O binary -S $< $@

xen/arch/riscv/vm_event.c

@@ -0,0 +1,19 @@
+#include <xen/bug.h>
+
+struct vm_event_st;
+struct vcpu;
+
+void vm_event_fill_regs(struct vm_event_st *req)
+{
+    BUG_ON("unimplemented");
+}
+
+void vm_event_set_registers(struct vcpu *v, struct vm_event_st *rsp)
+{
+    BUG_ON("unimplemented");
+}
+
+void vm_event_monitor_next_interrupt(struct vcpu *v)
+{
+    /* Not supported on RISCV. */
+}