hv: emulate ACPI reset register for Service OS guest

Handle the PIO reset register that is defined in host ACPI:

Parse host FADT table to get the host reset register info, and emulate
it for Service OS:

- return all '1' for guest reads because the read behavior is not defined
  in ACPI.
- ignore guest writes with the reset value to stop it from resetting host;
  if guest writes other values, passthru it to hardware in case the reset
  register supports other functionalities.

Tracked-On: #2700
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/arch/x86/configs/apl-mrb/platform_acpi_info.h

@@ -20,6 +20,11 @@
 #define WAKE_VECTOR_32		0x7A86BBDCUL
 #define WAKE_VECTOR_64		0x7A86BBE8UL
 
+/* reset register */
+#define RESET_REGISTER_ADDRESS	0xCF9U
+#define RESET_REGISTER_VALUE	0x0EU
+#define RESET_REGISTER_SPACE_ID SPACE_SYSTEM_IO
+
 /* DRHD of DMAR */
 #define DRHD_COUNT		2U
 

hypervisor/arch/x86/configs/platform_acpi_info.h

@@ -20,6 +20,10 @@
 #define WAKE_VECTOR_32		0UL
 #define WAKE_VECTOR_64		0UL
 
+#define RESET_REGISTER_ADDRESS	0UL
+#define RESET_REGISTER_VALUE	0UL
+#define RESET_REGISTER_SPACE_ID 0UL
+
 /* DRHD of DMAR */
 #define DRHD_COUNT		0U