diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3b3acb7f1b07..5a72c98e60bc 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -785,6 +785,9 @@ config PARAVIRT_SPINLOCKS
 
 	  If you are unsure how to answer this question, answer Y.
 
+config X86_HV_CALLBACK_VECTOR
+	def_bool n
+
 source "arch/x86/xen/Kconfig"
 
 config KVM_GUEST
@@ -836,6 +839,17 @@ config JAILHOUSE_GUEST
 	  cell. You can leave this option disabled if you only want to start
 	  Jailhouse and run Linux afterwards in the root cell.
 
+config ACRN_GUEST
+	bool "ACRN Guest support"
+	depends on X86_64
+	select X86_HV_CALLBACK_VECTOR
+	help
+	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
+	  a flexible, lightweight reference open-source hypervisor, built with
+	  real-time and safety-criticality in mind. It is built for embedded
+	  IOT with small footprint and real-time features. More details can be
+	  found in https://projectacrn.org/.
+
 endif #HYPERVISOR_GUEST
 
 source "arch/x86/Kconfig.cpu"
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 15f0749d0a15..a829dd3117d0 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1164,6 +1164,11 @@ apicinterrupt3 HYPERV_STIMER0_VECTOR \
 	hv_stimer0_callback_vector hv_stimer0_vector_handler
 #endif /* CONFIG_HYPERV */
 
+#if IS_ENABLED(CONFIG_ACRN_GUEST)
+apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
+	acrn_hv_callback_vector acrn_hv_vector_handler
+#endif
+
 idtentry debug			do_debug		has_error_code=0	paranoid=1 shift_ist=IST_INDEX_DB ist_offset=DB_STACK_OFFSET
 idtentry int3			do_int3			has_error_code=0	create_gap=1
 idtentry stack_segment		do_stack_segment	has_error_code=1
diff --git a/arch/x86/include/asm/acrn.h b/arch/x86/include/asm/acrn.h
new file mode 100644
index 000000000000..4adb13f08af7
--- /dev/null
+++ b/arch/x86/include/asm/acrn.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_ACRN_H
+#define _ASM_X86_ACRN_H
+
+extern void acrn_hv_callback_vector(void);
+#ifdef CONFIG_TRACING
+#define trace_acrn_hv_callback_vector acrn_hv_callback_vector
+#endif
+
+extern void acrn_hv_vector_handler(struct pt_regs *regs);
+#endif /* _ASM_X86_ACRN_H */
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index d9069bb26c7f..07533795b8d2 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -37,7 +37,7 @@ typedef struct {
 #ifdef CONFIG_X86_MCE_AMD
 	unsigned int irq_deferred_error_count;
 #endif
-#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
+#ifdef CONFIG_X86_HV_CALLBACK_VECTOR
 	unsigned int irq_hv_callback_count;
 #endif
 #if IS_ENABLED(CONFIG_HYPERV)
diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h
index 8c5aaba6633f..50a30f6c668b 100644
--- a/arch/x86/include/asm/hypervisor.h
+++ b/arch/x86/include/asm/hypervisor.h
@@ -29,6 +29,7 @@ enum x86_hypervisor_type {
 	X86_HYPER_XEN_HVM,
 	X86_HYPER_KVM,
 	X86_HYPER_JAILHOUSE,
+	X86_HYPER_ACRN,
 };
 
 #ifdef CONFIG_HYPERVISOR_GUEST
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 89e76523cedc..d7a1e5a9331c 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_X86_CPU_RESCTRL)		+= resctrl/
 obj-$(CONFIG_X86_LOCAL_APIC)		+= perfctr-watchdog.o
 
 obj-$(CONFIG_HYPERVISOR_GUEST)		+= vmware.o hypervisor.o mshyperv.o
+obj-$(CONFIG_ACRN_GUEST)		+= acrn.o
 
 ifdef CONFIG_X86_FEATURE_NAMES
 quiet_cmd_mkcapflags = MKCAP   $@
diff --git a/arch/x86/kernel/cpu/acrn.c b/arch/x86/kernel/cpu/acrn.c
new file mode 100644
index 000000000000..676022e71791
--- /dev/null
+++ b/arch/x86/kernel/cpu/acrn.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ACRN detection support
+ *
+ * Copyright (C) 2019 Intel Corporation. All rights reserved.
+ *
+ * Jason Chen CJ <jason.cj.chen@intel.com>
+ * Zhao Yakui <yakui.zhao@intel.com>
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <asm/acrn.h>
+#include <asm/apic.h>
+#include <asm/desc.h>
+#include <asm/hypervisor.h>
+#include <asm/irq_regs.h>
+
+static uint32_t __init acrn_detect(void)
+{
+	return hypervisor_cpuid_base("ACRNACRNACRN\0\0", 0);
+}
+
+static void __init acrn_init_platform(void)
+{
+	/* Setup the IDT for ACRN hypervisor callback */
+	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, acrn_hv_callback_vector);
+}
+
+static bool acrn_x2apic_available(void)
+{
+	/*
+	 * x2apic is not supported for now. Future enablement will have to check
+	 * X86_FEATURE_X2APIC to determine whether x2apic is supported in the
+	 * guest.
+	 */
+	return false;
+}
+
+static void (*acrn_intr_handler)(void);
+
+__visible void __irq_entry acrn_hv_vector_handler(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	/*
+	 * The hypervisor requires that the APIC EOI should be acked.
+	 * If the APIC EOI is not acked, the APIC ISR bit for the
+	 * HYPERVISOR_CALLBACK_VECTOR will not be cleared and then it
+	 * will block the interrupt whose vector is lower than
+	 * HYPERVISOR_CALLBACK_VECTOR.
+	 */
+	entering_ack_irq();
+	inc_irq_stat(irq_hv_callback_count);
+
+	if (acrn_intr_handler)
+		acrn_intr_handler();
+
+	exiting_irq();
+	set_irq_regs(old_regs);
+}
+
+const __initconst struct hypervisor_x86 x86_hyper_acrn = {
+	.name                   = "ACRN",
+	.detect                 = acrn_detect,
+	.type			= X86_HYPER_ACRN,
+	.init.init_platform     = acrn_init_platform,
+	.init.x2apic_available  = acrn_x2apic_available,
+};
diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index 479ca4728de0..87e39ad8d873 100644
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -32,6 +32,7 @@ extern const struct hypervisor_x86 x86_hyper_xen_pv;
 extern const struct hypervisor_x86 x86_hyper_xen_hvm;
 extern const struct hypervisor_x86 x86_hyper_kvm;
 extern const struct hypervisor_x86 x86_hyper_jailhouse;
+extern const struct hypervisor_x86 x86_hyper_acrn;
 
 static const __initconst struct hypervisor_x86 * const hypervisors[] =
 {
@@ -49,6 +50,9 @@ static const __initconst struct hypervisor_x86 * const hypervisors[] =
 #ifdef CONFIG_JAILHOUSE_GUEST
 	&x86_hyper_jailhouse,
 #endif
+#ifdef CONFIG_ACRN_GUEST
+	&x86_hyper_acrn,
+#endif
 };
 
 enum x86_hypervisor_type x86_hyper_type;
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index cc496eb7a8d2..4215653f8a8e 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -135,7 +135,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 		seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
 	seq_puts(p, "  Machine check polls\n");
 #endif
-#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
+#ifdef CONFIG_X86_HV_CALLBACK_VECTOR
 	if (test_bit(HYPERVISOR_CALLBACK_VECTOR, system_vectors)) {
 		seq_printf(p, "%*s: ", prec, "HYP");
 		for_each_online_cpu(j)
diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c
index ba95bc70460d..6857b4577f17 100644
--- a/arch/x86/kernel/jailhouse.c
+++ b/arch/x86/kernel/jailhouse.c
@@ -203,7 +203,7 @@ bool jailhouse_paravirt(void)
 	return jailhouse_cpuid_base() != 0;
 }
 
-static bool jailhouse_x2apic_available(void)
+static bool __init jailhouse_x2apic_available(void)
 {
 	/*
 	 * The x2APIC is only available if the root cell enabled it. Jailhouse
diff --git a/arch/x86/platform/geode/alix.c b/arch/x86/platform/geode/alix.c
index 8d4daca81eda..c33f744b5388 100644
--- a/arch/x86/platform/geode/alix.c
+++ b/arch/x86/platform/geode/alix.c
@@ -20,7 +20,6 @@
 #include <linux/moduleparam.h>
 #include <linux/leds.h>
 #include <linux/platform_device.h>
-#include <linux/gpio.h>
 #include <linux/input.h>
 #include <linux/gpio_keys.h>
 #include <linux/dmi.h>
diff --git a/arch/x86/platform/geode/geos.c b/arch/x86/platform/geode/geos.c
index 136974ec9a90..73a3f49b4eb6 100644
--- a/arch/x86/platform/geode/geos.c
+++ b/arch/x86/platform/geode/geos.c
@@ -18,7 +18,6 @@
 #include <linux/string.h>
 #include <linux/leds.h>
 #include <linux/platform_device.h>
-#include <linux/gpio.h>
 #include <linux/input.h>
 #include <linux/gpio_keys.h>
 #include <linux/dmi.h>
diff --git a/arch/x86/platform/geode/net5501.c b/arch/x86/platform/geode/net5501.c
index 2c24d8d30436..163e1b545517 100644
--- a/arch/x86/platform/geode/net5501.c
+++ b/arch/x86/platform/geode/net5501.c
@@ -18,7 +18,6 @@
 #include <linux/string.h>
 #include <linux/leds.h>
 #include <linux/platform_device.h>
-#include <linux/gpio.h>
 #include <linux/input.h>
 #include <linux/gpio_keys.h>
 
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index e07abefd3d26..ba5a41828e9d 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -7,6 +7,7 @@ config XEN
 	bool "Xen guest support"
 	depends on PARAVIRT
 	select PARAVIRT_CLOCK
+	select X86_HV_CALLBACK_VECTOR
 	depends on X86_64 || (X86_32 && X86_PAE)
 	depends on X86_LOCAL_APIC && X86_TSC
 	help
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index c423e57ae888..9a59957922d4 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -6,6 +6,7 @@ config HYPERV
 	tristate "Microsoft Hyper-V client drivers"
 	depends on X86 && ACPI && X86_LOCAL_APIC && HYPERVISOR_GUEST
 	select PARAVIRT
+	select X86_HV_CALLBACK_VECTOR
 	help
 	  Select this option to run Linux as a Hyper-V client operating
 	  system.