[XEN PATCH] x86/hvm: make ACPI PM timer support optional

[Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>]

Introduce config option X86_PMTIMER so that pmtimer driver can be disabled on
systems that don't need it.

Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>
---
 xen/arch/x86/Kconfig               |  9 +++++++++
 xen/arch/x86/hvm/Makefile          |  2 +-
 xen/arch/x86/include/asm/acpi.h    |  5 +++++
 xen/arch/x86/include/asm/hvm/vpt.h | 10 ++++++++++
 4 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index 62f0b5e0f4..0a762be14e 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -385,6 +385,15 @@ config ALTP2M
 
          If unsure, stay with defaults.
 
+config X86_PMTIMER
+       bool "ACPI PM timer emulation support" if EXPERT
+       default y
+       depends on HVM
+       help
+         Build pmtimer driver that emulates ACPI PM timer for HVM guests.
+
+         If unsure, say Y.
+
 endmenu
 
 source "common/Kconfig"
diff --git a/xen/arch/x86/hvm/Makefile b/xen/arch/x86/hvm/Makefile
index 4c1fa5c6c2..321241f0bf 100644
--- a/xen/arch/x86/hvm/Makefile
+++ b/xen/arch/x86/hvm/Makefile
@@ -18,7 +18,7 @@ obj-y += irq.o
 obj-y += monitor.o
 obj-y += mtrr.o
 obj-y += nestedhvm.o
-obj-y += pmtimer.o
+obj-$(CONFIG_X86_PMTIMER) += pmtimer.o
 obj-y += quirks.o
 obj-y += rtc.o
 obj-y += save.o
diff --git a/xen/arch/x86/include/asm/acpi.h b/xen/arch/x86/include/asm/acpi.h
index 217819dd61..8d92014ae9 100644
--- a/xen/arch/x86/include/asm/acpi.h
+++ b/xen/arch/x86/include/asm/acpi.h
@@ -150,8 +150,13 @@ void acpi_mmcfg_init(void);
 /* Incremented whenever we transition through S3. Value is 1 during boot. */
 extern uint32_t system_reset_counter;
 
+#ifdef CONFIG_X86_PMTIMER
 void hvm_acpi_power_button(struct domain *d);
 void hvm_acpi_sleep_button(struct domain *d);
+#else
+static inline void hvm_acpi_power_button(struct domain *d) {}
+static inline void hvm_acpi_sleep_button(struct domain *d) {}
+#endif
 
 /* suspend/resume */
 void save_rest_processor_state(void);
diff --git a/xen/arch/x86/include/asm/hvm/vpt.h 
b/xen/arch/x86/include/asm/hvm/vpt.h
index 0b92b28625..333b346068 100644
--- a/xen/arch/x86/include/asm/hvm/vpt.h
+++ b/xen/arch/x86/include/asm/hvm/vpt.h
@@ -187,10 +187,20 @@ void rtc_deinit(struct domain *d);
 void rtc_reset(struct domain *d);
 void rtc_update_clock(struct domain *d);
 
+#ifdef CONFIG_X86_PMTIMER
 void pmtimer_init(struct vcpu *v);
 void pmtimer_deinit(struct domain *d);
 void pmtimer_reset(struct domain *d);
 int pmtimer_change_ioport(struct domain *d, uint64_t version);
+#else
+static inline void pmtimer_init(struct vcpu *v) {}
+static inline void pmtimer_deinit(struct domain *d) {}
+static inline void pmtimer_reset(struct domain *d) {}
+static inline int pmtimer_change_ioport(struct domain *d, uint64_t version)
+{
+    return -ENODEV;
+}
+#endif
 
 void hpet_init(struct domain *d);
 void hpet_deinit(struct domain *d);
-- 
2.25.1