[XEN PATCH v1 1/3] x86/hvm: introduce config option for ACPI PM timer

[Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>]

Introduce config option X86_PMTIMER so that pmtimer emulation driver can later
be made configurable and be disabled on systems that don't need it.

As a first step the option is hidden from user, thus not making any functional
changes here.

Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>
CC: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/Kconfig               |  3 +++
 xen/arch/x86/hvm/Makefile          |  2 +-
 xen/arch/x86/include/asm/acpi.h    |  5 +++++
 xen/arch/x86/include/asm/domain.h  |  3 ++-
 xen/arch/x86/include/asm/hvm/vpt.h | 10 ++++++++++
 5 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index 9cdd04721a..95275dc17e 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -144,6 +144,9 @@ config INTEL_VMX
          If your system includes a processor with Intel VT-x support, say Y.
          If in doubt, say Y.
 
+config X86_PMTIMER
+       def_bool HVM
+
 config XEN_SHSTK
        bool "Supervisor Shadow Stacks"
        depends on HAS_AS_CET_SS
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/domain.h 
b/xen/arch/x86/include/asm/domain.h
index bdcdb8de09..3f65bfd190 100644
--- a/xen/arch/x86/include/asm/domain.h
+++ b/xen/arch/x86/include/asm/domain.h
@@ -496,7 +496,8 @@ struct arch_domain
 
 #define has_vlapic(d)      (!!((d)->arch.emulation_flags & X86_EMU_LAPIC))
 #define has_vhpet(d)       (!!((d)->arch.emulation_flags & X86_EMU_HPET))
-#define has_vpm(d)         (!!((d)->arch.emulation_flags & X86_EMU_PM))
+#define has_vpm(d)         (IS_ENABLED(CONFIG_X86_PMTIMER) && \
+                            !!((d)->arch.emulation_flags & X86_EMU_PM))
 #define has_vrtc(d)        (!!((d)->arch.emulation_flags & X86_EMU_RTC))
 #define has_vioapic(d)     (!!((d)->arch.emulation_flags & X86_EMU_IOAPIC))
 #define has_vpic(d)        (!!((d)->arch.emulation_flags & X86_EMU_PIC))
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