hv: implement lowlevel S3 enter/wakeup

The S3 enter lowlevel routine saves the cpu context to memory
and enter S3 state

The S3 wakeup lowlevel routine restore cpu context and return.

Signed-off-by: Zheng Gen <gen.zheng@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/include/arch/x86/host_pm.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (C) <2018> Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef	HOST_PM_H
+
+extern void __enter_s3(struct vm *vm, uint32_t pm1a_cnt_val,
+		uint32_t pm1b_cnt_val);
+extern void restore_s3_context(void);
+
+#endif	/* ARCH_X86_PM_H */

hypervisor/include/arch/x86/hv_arch.h

@@ -19,6 +19,7 @@
 #include <vcpu.h>
 #include <trusty.h>
 #include <guest_pm.h>
+#include <host_pm.h>
 #include <vm.h>
 #include <cpuid.h>
 #include <mmu.h>